CN107402252A - High temperature refractory mineral laser BrF5Method oxygen isotope composition analysis system and method - Google Patents

Abstract

The invention belongs to the field of determination of isotope composition of oxygen-containing minerals, and specifically discloses a high-temperature refractory mineral laser-BrF ₅ method oxygen isotope composition analysis system and method, and the reagent purification system of the system is respectively reacted/separated/purified with a sample system and a vacuum system One end of the sample reaction/separation/purification system is connected to one end of the product collection/determination system, and the other end of the product collection/determination system is connected to the vacuum system; the method is as follows: put the high-temperature refractory mineral sample to be analyzed into In the analysis system; bake and vacuumize the entire analysis system; pre-fluorinate the high-temperature refractory mineral samples in the sample laser pool; perform fluorination reaction on the high-temperature refractory mineral samples in the sample laser pool—O isotope Extraction; O ₂ purification, collection and mass spectrometry; waste collection and treatment. The invention improves the analysis and test accuracy and the analysis and test efficiency of the high-temperature refractory mineral oxygen isotope.

Description

High-temperature refractory mineral laser-BrF5 oxygen isotope composition analysis system and method

technical field

The invention belongs to the field of isotopic composition determination of oxygen-containing minerals, and in particular relates to a laser-BrF ₅ oxygen isotopic composition analysis system and method for high-temperature refractory minerals.

Background technique

Oxygen isotope is an important means to study the source, migration and evolution of ore-forming materials and ore-forming fluids, and provides a theoretical basis for elucidating the ore-forming mechanism of ore deposits. Fully extracting and transforming oxygen in minerals and purifying and collecting them is the prerequisite for the analysis of oxygen isotope composition of high-temperature refractory minerals (high-temperature refractory minerals are usually formed at temperatures above 800°C, and the highest can reach above 2000°C).

In terms of oxygen isotope analysis methods of high-temperature refractory minerals, the conventional bromine pentafluoride method is basically used for extraction and analysis at home and abroad, but this method has several disadvantages: 1) The amount of sample required for experimental analysis is relatively large, at least 20 mg of bromine pentafluoride is required. 2) The sample preparation cycle is long, resulting in low analysis efficiency; 3) Due to the long chemical reaction time, the static vacuum of the system is extremely high, and the reactor uses It is difficult to ensure the vacuum degree of the system under the high and low temperature alternating environment, and it is easy to cause the oxygen in the air to enter the system and undergo isotope exchange with the sample. In addition, there is a great safety hazard because of the need for overnight reaction; 4) the used The nickel reaction tube is easy to be polluted and difficult to clean after analyzing several batches of high-temperature refractory samples, which seriously affects the sample analysis and test results; 5) the use of external heating can easily lead to the production of nickel fluoride in the reactor, which affects the oxygen isotope composition of the sample determination.

In terms of test objects, the traditional method is to convert the oxygen generated by the reaction with graphite into _CO2 under high temperature conditions for mass spectrometry. Because carbon has two isotopes of ¹² C and ¹³ C involved in the calculation, the measurement results need to be corrected, and the conversion process is likely to cause O isotope fractionation; the conversion system needs to introduce glass pipelines, and the glass piston needs to be regularly coated with vacuum grease to ensure the sealing performance of the piston And rotation flexibility, the system is exposed to the atmosphere during the process of applying vacuum grease, oxygen and water vapor in the air enter the system to cause pollution, and the vacuum sealing grease is easy to cause cross-contamination due to oxygen.

Contents of the invention

The purpose of the present invention is to provide a new high-temperature refractory mineral laser-BrF ₅ method oxygen isotope composition analysis system and method, to solve the problem of high-temperature refractory minerals in the oxygen isotope analysis of large sample consumption, low spatial resolution, and insufficient oxygen extraction. The conversion process is easy to cause problems such as oxygen isotope fractionation, which improves the accuracy and efficiency of analysis and testing.

The technical solution for realizing the object of the present invention: a high-temperature refractory mineral laser-BrF ₅ method oxygen isotope composition analysis system, the system includes a reagent purification system, a sample reaction/separation/purification system, a product collection/measurement system and a vacuum system; The purification system is connected to one end of the sample reaction/separation/purification system and the vacuum system respectively, the other end of the sample reaction/separation/purification system is connected to one end of the product collection/measurement system, and the other end of the product collection/measurement system is connected to the vacuum system.

The reagent purification system includes a rotary vane mechanical vacuum pump, a first metal cold trap, a first bromine pentafluoride storage tank, a vacuum pressure gauge, a 1/2inch stainless steel pipeline, a second bromine pentafluoride storage tank, a third five The bromine fluoride storage tank, the second metal cold trap, the top of the 1/2inch stainless steel pipe is equipped with a vacuum pressure gauge, and the upper part of one side of the 1/2inch stainless steel pipe is respectively connected with the top outlet of the first bromine pentafluoride storage tank, the first The inlet of the metal cold trap is connected, the outlet of the first metal cold trap is connected to the inlet end of the rotary vane mechanical vacuum pump; the bottom of one side of the 1/2inch stainless steel pipe is respectively connected to the second bromine pentafluoride storage tank and the third bromine pentafluoride storage tank The outlet on the top of the tank is connected, and the upper part of the other side of the 1/2inch stainless steel pipe is connected to the inlet of the second metal cold trap.

A fifth 1/4inch metal valve is arranged between the top of the 1/2inch stainless steel pipe and the vacuum pressure gauge.

A fourth 1/4inch metal valve is provided between the 1/2inch stainless steel pipeline and the first bromine pentafluoride storage tank, and a third 1/4inch valve is provided between the 1/2inch stainless steel pipeline and the first metal cold trap inlet. Metal valve, there is a second 1/4inch metal valve between the outlet of the first metal cold trap and the inlet end of the rotary vane mechanical vacuum pump, and there is a second 1/4inch metal valve in parallel with the second 1/4inch metal valve at the outlet of the first metal cold trap First 1/4inch metal valve.

The twelfth 1/4inch metal valve, the eleventh 1/4inch metal valve, the twelfth 1/4inch metal valve are arranged between the bottom of the 1/2inch stainless steel pipe and the top outlet of the third bromine pentafluoride storage tank 10th 1/4inch metal valve, ninth 1/4inch metal valve, tenth 1/4inch metal valve and ninth An eighth 1/4inch metal valve connected to both of the 1/4inch metal valves is arranged.

The middle part of one side of the 1/2inch stainless steel pipe is also connected to one end of the seventh 1/4inch metal valve, and the other end of the seventh 1/4inch metal valve is connected to the sixth 1/4inch metal valve 1 .

The other side of the 1/2inch stainless steel pipe and the inlet of the second metal cold trap are provided with a thirteenth 1/4inch metal valve connection, and the outlet of the second metal cold trap is provided with a first spherical bellows metal valve, A first spherical bellows metal valve is connected to the vacuum system.

The sample reaction/separation/purification system includes a third metal cold trap, a _CO2 infrared laser, an imaging observation system, a sample laser pool, a fourth metal cold trap, a fifth metal cold trap, a KBr metal heat trap and a sixth metal Cold trap, the inlet of the third metal cold trap is connected to the thirteenth 1/4inch metal valve of the reagent purification system, the outlet of the third metal cold trap is connected to one end of the sample laser pool, and the other end of the sample laser pool is connected to the fourth metal cold trap One end of the metal cold trap is connected, the other end of the fourth metal cold trap is connected to one end of the fifth metal cold trap, the other end of the fifth metal cold trap is connected to one end of the KBr metal heat well, and the other end of the KBr metal heat well is connected to the sixth metal heat trap. One end of the cold trap is connected, and the other end of the sixth metal cold trap is connected to the product collection/measurement system; a CO ₂ infrared laser is installed above the sample laser pool, and an imaging observation system is installed on the CO ₂ infrared laser.

A fourteenth 1/4inch metal valve is provided between the entrance of the third metal cold trap and the 1/2inch stainless steel pipe, and a fifteenth 1/4inch metal valve is provided between the outlet of the third metal cold trap and the sample laser pool, A second spherical bellows metal valve is provided between the sample laser pool and the fourth metal cold trap, a third spherical bellows metal valve is provided between the fourth metal cold trap and the fifth metal cold trap, and the fifth metal cold trap is connected to the The fourth spherical bellows metal valve is set between the KBr metal hot trap, the fifth spherical bellows metal valve is set between the KBr metal hot well and the sixth metal cold trap, and the sixth metal cold trap and the product collection/measurement system There is a sixth spherical bellows metal valve.

The product collection/measurement system includes a capacitance vacuum gauge, the seventh spherical bellows metal valve, the eighth spherical bellows metal valve, 1/2inch stainless steel collection pipe, turbomolecular pump, isotope mass spectrometer, the seventh spherical bellows metal One end of the valve is connected to the sixth spherical bellows metal valve of the sample reaction/separation/purification system through a pipeline, and the capacitance vacuum gauge is respectively connected to the sixth spherical bellows metal valve and the seventh spherical bellows metal valve; the seventh spherical bellows The other end of the metal valve is respectively connected with the metal valve of the eighth spherical bellows, the 1/2inch stainless steel collection pipe and the isotope mass spectrometer.

The vacuum system includes an ionization vacuum gauge and a turbomolecular pump with a rotary vane mechanical pump as the front stage, the turbomolecular pump is connected to the first spherical bellows metal valve of the reagent purification system, and the ionization vacuum gauge is connected to the turbomolecular pump, The first ball bellows metal valve connection.

The analysis system also includes a waste treatment system, and the waste treatment system includes a first 1/4inch metal valve, a second 1/4inch metal valve, a rotary vane mechanical vacuum pump, a first metal cold trap, and a third 1/4inch metal valve , the fourth 1/4inch metal valve, the first bromine pentafluoride storage tank, the fifth 1/4inch metal valve, 1/2inch stainless steel pipe, the sixth 1/4inch metal valve, the seventh 1/4inch metal valve, the tenth Four 1/4inch metal valves, the third metal cold trap and the fifteenth 1/4inch metal valve, one end of the first 1/4inch metal valve is connected to the outlet of the first metal cold trap, one end of the second 1/4inch metal valve is connected to The first 1/4inch metal valve is connected to the outlet of the first metal cold trap, and the other end of the second 1/4inch metal valve is connected to the intake end of the rotary vane mechanical vacuum pump; the inlet of the first metal cold trap is connected to the third 1/4 inch metal valve. One end of the 4inch metal valve is connected, the other end of the third 1/4inch metal valve is connected to the 1/2inch stainless steel pipe; one end of the fourth 1/4inch metal valve is connected to the first bromine pentafluoride storage tank, and the fourth 1/4inch The other end of the metal valve is respectively connected with the third 1/4inch metal valve and 1/2inch stainless steel pipe; the other end of the fifth 1/4inch metal valve is connected with the 1/2inch stainless steel pipe; one end of the seventh 1/4inch metal valve is connected with 1/2inch stainless steel pipe connection, the other end of the seventh 1/4inch metal valve is connected to one end of the sixth 1/4inch metal valve; one end of the fourteenth 1/4inch metal valve is connected to 1/2inch stainless steel pipe, the fourteenth The other end of the 1/4inch metal valve is connected to the inlet of the third metal cold trap, and the outlet of the third metal cold trap is connected to one end of the fifteenth 1/4inch metal valve.

A method for analyzing the oxygen isotope composition of high-temperature refractory mineral laser-BrF ₅ method using the above-mentioned high-temperature refractory mineral laser-BrF ₅ method oxygen isotope composition analysis system, the method specifically includes the following steps:

Step 1. Load the high-temperature refractory mineral sample to be analyzed into the analysis system;

Step 2. Baking and vacuuming the entire analysis system to remove gas;

Step 3, pre-fluorinating the high-temperature refractory mineral sample in the sample laser pool;

Step 4, performing fluorination reaction-O isotope extraction on the high-temperature refractory mineral sample in the sample laser pool;

Step ₅ , O purification, collection and mass spectrometry;

Step 6, waste collection and treatment.

The specific steps of step 1 are as follows: remove the _CO2 infrared laser and imaging observation system from directly above the sample laser pool, close all valves in the analysis system, open the sample laser pool, and place the high-temperature refractory to be analyzed Put the mineral sample into a clean sample tray and make a record, and place the sample tray containing the high-temperature refractory mineral sample to be analyzed in the sample laser pool, close and tighten the sample laser pool, and complete the sample loading operation.

The specific steps of the step 2 are as follows: turn on the power supply of the heating belt, heat and bake the analysis system; put a liquid nitrogen cup on the first metal cold trap coat, open the fifteenth 1/4inch metal valve and the fourteenth 1/4inch metal valve, first diffuse part of the air in the sample laser pool into the main pipe of 1/2inch stainless steel pipe; close the fifteenth 1/4inch metal valve, open the third 1/4inch metal valve and the second 1/4inch metal valve For the valves, the low vacuum in the 1/2inch stainless steel pipeline is drawn by the rotary vane mechanical vacuum pump, and the fourteenth 1/4inch metal valve and the third 1/4inch metal valve are closed. Slowly open the fifteenth 1/4inch metal valve, diffuse the air in the sample laser pool into the 1/2inch stainless steel pipe and draw a low vacuum through the rotary vane mechanical vacuum pump, and finally fully open the fifteenth 1/4inch metal valve , the fourteenth 1/4inch metal valve, the tenth 1/4inch metal valve and the twelfth 1/4inch metal valve; open the third 1/4inch metal valve and the second 1/4inch metal valve to draw samples in the laser pool. After 20 minutes of vacuum, close the third 1/4inch metal valve; put a liquid nitrogen cup on the second metal cold trap, open the first spherical bellows metal valve, the third spherical bellows metal valve, the fourth spherical bellows metal valve, The fifth spherical bellows metal valve, the sixth spherical bellows metal valve, the seventh spherical bellows metal valve and the eighth spherical bellows metal valve are connected to the turbomolecular pump to pump a high vacuum for the system and continue to vacuum for 30 minutes. The gauge monitors system vacuum.

The heating and baking temperature of the system in step 2 is 250° C.; the turbomolecular pump pumps the system to a high vacuum to a vacuum degree of 10 ⁻⁶ Pa.

The specific steps of described step 3 are as follows: turn off the power supply of the heating belt, wait for the analysis system to return to room temperature, put a liquid nitrogen cup on the third metal cold trap and the first bromine pentafluoride storage tank coat; close the tenth 1/4inch Metal valve, the twelfth 1/4inch metal valve, the fourteenth 1/4inch metal valve, the fifteenth 1/4inch metal valve and the thirteenth 1/4inch metal valve, open the top of the third bromine pentafluoride storage tank After the eleventh 1/4inch metal valve, slowly half-open the twelfth 1/4inch metal valve, control the pressure of the BrF ₅ reagent diffused into the main pipe of the 1/2inch stainless steel pipe through the vacuum pressure gauge, and close the twelfth 1/4inch metal valve Valve; after opening the fourteenth 1/4inch metal valve, the BrF ₅ in the main pipe of the 1/2inch stainless steel pipe is frozen into the third metal cold trap, close the fourteenth 1/4inch metal valve, and remove the BrF 5 outside the third metal cold trap After the liquid nitrogen cup and the third metal cold trap are naturally thawed and returned to room temperature; open the fifteenth 1/4inch metal valve, diffuse the BrF ₅ reagent into the sample laser pool for 2min, then open the fourteenth 1/4inch metal valve, The fourth 1/4inch metal valve, freeze the residual BrF ₅ reagent into the first bromine pentafluoride storage tank, open the third 1/4inch metal valve and the second 1/4inch metal valve, and the residual reactants that cannot be frozen go through After the first metal cold trap is frozen, it is sucked away by a rotary vane mechanical vacuum pump, and the fourth 1/4inch metal valve on the first bromine pentafluoride storage tank is closed.

In the step 3, the vacuum pressure gauge controls the pressure of the BrF ₅ reagent diffused into the main pipeline of the 1/2 inch stainless steel pipe to be 0.02MPa.

Repeat the above step 3 three times to fluorinate the sample and the inner wall of the sample laser cell. The last BrF ₅ reagent is kept in the sample laser cell for 2 hours to completely remove the high-temperature refractory mineral sample and the water vapor adsorbed on the inner wall of the sample laser cell.

The specific steps of step 4 are as follows: after the high-temperature refractory mineral sample in the sample laser pool has been pre-fluorinated, the analysis system is evacuated to a high vacuum of 10 ^-6 Pa and then pumped for 30 minutes, and all valves are closed; Put a liquid nitrogen cup on the metal cold trap, open the eleventh 1/4inch metal valve on the third bromine pentafluoride storage tank, open the fifth 1/4inch metal valve, and slowly half-open the twelfth 1/4inch metal valve , the 0.01MPa purified BrF ₅ reagent is controlled by a vacuum pressure gauge to diffuse into the 1/2inch stainless steel main pipe, close the eleventh 1/4inch metal valve and the twelfth 1/4inch metal valve; open the fourteenth 1 /4inch metal valve to freeze the BrF ₅ reagent in the pipeline into the third metal cold trap, close the fourteenth 1/4inch metal valve; remove the liquid nitrogen cup outside the third metal cold trap to return to room temperature, open the fifteenth 1 The /4inch metal valve diffuses the BrF ₅ reagent into the sample laser pool, closes the fifteenth 1/4inch metal valve; adjusts the CO ₂ infrared laser to the top of the sample laser pool, and locates the high-temperature refractory mineral sample to be analyzed through the imaging observation system Directly above, guide the laser beam of the CO ₂ infrared laser into the sample hole of the high-temperature refractory mineral sample to be analyzed, adjust the laser spot size and laser energy of the CO ₂ infrared laser, and heat the high-temperature refractory mineral sample to be analyzed. The refractory mineral sample reacts with the _BrF5 reagent at high temperature to release oxygen and complete the O isotope extraction of the sample.

The specific steps of step 5 are as follows: put a liquid nitrogen cup on the fourth metal cold trap, the fifth metal cold trap, the sixth metal cold trap and the 1/2inch stainless steel collection tube, and slowly open the metal valve of the second spherical bellows , freeze the reactants and residual BrF ₅ reagents in the laser cell into the fourth metal cold trap; open the third spherical bellows metal valve after 10 minutes, and freeze the reactants and residual BrF ₅ reagents again through the fifth metal cold trap After 5min, the fourth spherical bellows metal valve is opened, and the reactant and residual BrF5 reagent are further absorbed by the KBr metal hot trap; after _5min , the fifth spherical bellows metal valve is opened, and the generated O is passed through the sixth metal cold trap. _2. Further freeze and purify; open the metal valve of the sixth spherical bellows after 5 minutes, and monitor the pressure of O ₂ generated by the reaction through a capacitance vacuum gauge; open the metal valve of the seventh spherical bellows, and O ₂ is collected into the filling In the 1/2inch stainless steel collection tube of the molecular sieve, monitor the _O2 being collected by a capacitance vacuum gauge, and close the metal valve of the seventh spherical bellows after the _O2 is completely collected; remove the liquid nitrogen outside the 1/2inch stainless steel collection tube, and restore After reaching room temperature, O ₂ is released, and the released O ₂ is introduced into an isotope mass spectrometer for isotope determination.

The 1/2inch stainless steel collecting tube in the described step 5 is filled with Molecular sieve.

The specific steps of described step 6 are as follows: put a liquid nitrogen cup on the first metal cold trap, the first bromine pentafluoride storage tank and the third metal cold trap outer jacket, close the sixth spherical bellows metal valve, open the third 1 /4inch metal valve, fourteenth 1/4inch metal valve, fifteenth 1/4inch metal valve, second spherical bellows metal valve, third spherical bellows metal valve, fourth spherical bellows metal valve and fifth spherical Bellows metal valve, after fully freezing the remaining BrF ₅ reagents and reactants in the system through the first metal cold trap, the third metal cold trap, the fourth metal cold trap, the fifth metal cold trap, and the sixth metal cold trap ;Slowly open the second 1/4inch metal valve and pump out the impurity gas that cannot be frozen by liquid nitrogen through the rotary vane mechanical vacuum pump, close the third 1/4inch metal valve, the fourth spherical bellows metal valve and the fifth spherical bellows metal Valve; remove the liquid nitrogen cup outside the third metal cold trap, the fourth metal cold trap, the fifth metal cold trap and the sixth metal cold trap, and after the cold trap returns to room temperature, open the fourth 1/4inch metal valve One metal cold trap, the third metal cold trap, the fourth metal cold trap, the _fifth metal cold trap, the residual BrF5 reagent frozen in the sixth metal cold trap and the reaction product are frozen in the first bromine pentafluoride storage tank; Close the fourth 1/4inch metal valve, open the third 1/4inch metal valve, the fourth spherical bellows metal valve and the fifth spherical bellows metal valve, and further evacuate the system pipeline through the rotary vane mechanical vacuum pump. The remaining impurities in the analysis system are frozen in the first metal cold trap; close all valves, remove the liquid nitrogen cup outside the first metal cold trap, and open the sixth 1/4inch metal valve, the seventh 1/4inch metal valve, The third 1/4inch metal valve and the first 1/4inch metal valve carry the residual waste gas into the lime bucket in the fume hood with Ar gas to complete waste disposal.

The beneficial technical effect of the present invention is that: the present invention adopts CO ₂ infrared laser as the heating device of high-temperature refractory mineral samples, and the high temperature generated by the laser can fluorinate high-temperature refractory minerals in a very short time to completely release oxygen, avoiding In the traditional method, the problem of oxygen isotope fractionation caused by the static vacuum reduction of the sample preparation system caused by the long reaction time is solved. At the same time, the laser spot is small, the energy is concentrated, the beam homogenization is high, and the power is continuously adjustable. Samples (less than 1mg) can be analyzed, and micro-area in-situ (125-6000um) analysis can also be realized for special samples; the gas path of the system is designed with 316 stainless steel metal pipelines, which avoids the use of vacuum sealing grease due to the use of glass pipelines in conventional methods Oxygen-containing components interfere; the metal pipeline and the outer wall of the laser pool are wrapped with heating tape, which is convenient for vacuum baking and degassing the system, and reduces the influence of oxygen and water vapor in the air on the sample test; The molecular sieve directly collects the oxygen generated by the reaction under the sufficient freezing of liquid nitrogen for mass spectrometry measurement, avoiding the problem of correcting the measurement results due to the introduction of graphite in the traditional method, and overcoming the problem of exposing the system to the atmosphere by regularly applying vacuum lubricating grease to the glass piston defects, while avoiding cross-contamination caused by the use of oxygen-containing vacuum sealing grease; the rotary vane mechanical pump is used as the front-stage turbomolecular pump as the high vacuum pump unit of the system to ensure that the whole system reaches a high degree of vacuum and further reduce the air containing The influence of oxygen gas on the experimental process; the combination of polytrifluoroethylene valve and spherical bellows valve is used to control the system to avoid the problem of valve body corrosion and sealing performance degradation caused by long-term contact with bromine pentafluoride reagent; The design of combining multiple cold traps and hot traps is used to purify the oxygen released by the reaction step by step, completely remove the by-products and residual bromine pentafluoride reagents generated by the reaction, and protect the collection system and isotope mass spectrometer; The bromine pentafluoride reagent storage tank is made of ethylene material, and the storage and use status of the reagent in the storage tank can be determined by visual observation, and three bromine pentafluoride reagent storage tanks are designed to store primary purity, advanced purity and reaction residue respectively Bromine pentafluoride; after the whole system is baked and the sample is pre-fluorinated to remove water vapor, the heating, reaction, purification and isotope analysis of a sample can be completed in 25 minutes, which greatly improves the analysis efficiency and obtains the precision and accuracy of the analysis results The accuracy is high, and the error range is better than ±0.2‰.

Description of drawings

Fig. 1 is a schematic diagram of a high-temperature refractory mineral laser-BrF ₅ method oxygen isotope composition analysis system provided by the present invention.

In the figure: 1 is the first 1/4inch metal valve, 2 is the second 1/4inch metal valve, 3 is the rotary vane mechanical vacuum pump, 4 is the first metal cold trap, 5 is the third 1/4inch metal valve, 6 The fourth 1/4inch metal valve, 7 is the first bromine pentafluoride storage tank, 8 is the vacuum pressure gauge, 9 is the fifth 1/4inch metal valve, 10 is 1/2inch stainless steel pipe, 11 is the sixth 1/4inch 4inch metal valve, 12 is the seventh 1/4inch metal valve, 13 is the eighth 1/4inch metal valve, 14 is the ninth 1/4inch metal valve, 15 is the second bromine pentafluoride storage tank, 16 is the tenth 1st /4inch metal valve, 17 is the eleventh 1/4inch metal valve, 18 is the third bromine pentafluoride storage tank, 19 is the twelfth 1/4inch metal valve, 20 is the thirteenth 1/4inch metal valve, 21 22 is the first spherical bellows metal valve, 23 is the 14th 1/4inch metal valve, 24 is the third metal cold trap, 25 is the 15th 1/4inch metal valve, 26 is CO ₂ infrared laser, 27 is the imaging observation system, 28 is the sample laser pool, 29 is the second spherical bellows metal valve, 30 is the fourth metal cold trap, 31 is the third spherical bellows metal valve, 32 is the fifth metal cold trap Well, 33 is the fourth spherical bellows metal valve, 34 is the KBr metal hot well, 35 is the fifth spherical bellows metal valve, 36 is the sixth metal cold trap, 37 is the sixth spherical bellows metal valve, 38 is the capacitor Vacuum gauge, 39 is the seventh spherical bellows metal valve, 40 is the eighth spherical bellows metal valve, 41 is filling 1/2 inch stainless steel collection tube of molecular sieve, 42 is an ionization vacuum gauge, 43 is a turbomolecular pump, 44 is an isotope mass spectrometer.

detailed description

The present invention will be described in further detail below in conjunction with the accompanying drawings and embodiments.

As shown in Figure 1, a high-temperature refractory mineral laser-BrF ₅ oxygen isotope composition analysis system, the system includes reagent purification system, sample reaction/separation/purification system, product collection/determination system, vacuum system and waste treatment system.

The reagent purification system includes the first 1/4inch metal valve 1, the second 1/4inch metal valve 2, the rotary vane mechanical vacuum pump 3, the first metal cold trap 4, the third 1/4inch metal valve 5, the fourth 1/4inch Metal valve 6, the first bromine pentafluoride storage tank 7, vacuum pressure gauge 8, the fifth 1/4inch metal valve 9, 1/2inch stainless steel pipe 10, the sixth 1/4inch metal valve 11, the seventh 1/4inch metal Valve 12, eighth 1/4inch metal valve 13, ninth 1/4inch metal valve 14, second bromine pentafluoride storage tank 15, tenth 1/4inch metal valve 16, eleventh 1/4inch metal valve 17, The third bromine pentafluoride storage tank 18, the twelfth 1/4inch metal valve 19, the thirteenth 1/4inch metal valve 20, the second metal cold trap 21 and the first spherical bellows metal valve 22. One end of the first 1/4inch metal valve 1 is connected to the outlet of the first metal cold trap 4 through a horizontal pipeline, one end of the second 1/4inch metal valve 2 is connected to the horizontal pipeline through a tee, and the second 1/4inch metal valve 2 The other end of the pipe is connected with the intake end of the rotary vane mechanical vacuum pump 3 through a pipeline. The inlet of the first metal cold trap 4 is connected to one end of the third 1/4inch metal valve 5 through a pipeline, and the other end of the third 1/4inch metal valve 5 is connected to the 1/2inch stainless steel pipeline 10 by welding the 1/4inch stainless steel pipeline; One end of the fourth 1/4inch metal valve 6 is connected to the top outlet of the first bromine pentafluoride storage tank 7 through a 1/4inch stainless steel pipeline, and the other end of the fourth 1/4inch metal valve 6 is respectively connected to the third 1/4 inch through a tee. 4inch metal valve 5, 1/2inch stainless steel pipe 10 connections. The vacuum pressure gauge 8 is connected to one end of the fifth 1/4inch metal valve 9 through a 1/4inch stainless steel pipe, the other end of the fifth 1/4inch metal valve 9 is welded to the 1/2inch stainless steel pipe 10, and the fifth 1/4inch metal valve The valve 9 controls the opening and closing of the vacuum pressure gauge 8 . One end of the seventh 1/4inch metal valve 12 is welded to the 1/2inch stainless steel pipe 10 through a pipeline, and the other end of the seventh 1/4inch metal valve 12 is connected to the sixth 1/4inch metal valve 11 through a pipeline. One end of the eighth 1/4inch metal valve 13 is connected with the bromine pentafluoride cylinder outside the system, the other end of the eighth 1/4inch metal valve 13 is connected with one end of the tenth 1/4inch metal valve 16 through a pipeline, and the tenth One end of the 1/4inch metal valve 16 is connected to one end of the twelfth 1/4inch metal valve 19 through a pipeline, and the other end of the twelfth 1/4inch metal valve 19 is connected to the 1/2inch stainless steel pipe 10 by welding; the ninth 1/4inch metal valve 19 is connected by welding; One end of the 4inch metal valve 14 is respectively connected to the eighth 1/4inch metal valve 13 and the tenth 1/4inch metal valve 16 through a tee, and the other end 14 of the ninth 1/4inch metal valve is connected to the second 1/4inch metal valve through a 1/4inch stainless steel pipeline. The top outlet of bromine pentafluoride storage tank 15 is connected; one end of the eleventh 1/4inch metal valve 17 is respectively connected to the tenth 1/4inch metal valve 16 and the twelfth 1/4inch metal valve 19 through a tee, and the eleventh The other end of the 1/4inch metal valve 17 is connected to the top outlet of the third bromine pentafluoride storage tank 18 through a 1/4inch stainless steel pipeline. One end of the thirteenth 1/4inch metal valve 20 and one end of the fourteenth 1/4inch metal valve 23 are connected to the 1/2inch stainless steel pipe 10 through pipeline welding; the other end of the thirteenth 1/4inch metal valve 20 is connected through the pipeline It is connected with the inlet of the second metal cold trap 21, and the outlet of the second metal cold trap 21 is connected with one end of the first spherical bellows metal valve 22 through a pipeline.

The sample reaction/separation/purification system includes the fourteenth 1/4inch metal valve 23, the third metal cold trap 24, the fifteenth 1/4inch metal valve 25, the CO ₂ infrared laser 26, the imaging observation system 27, and the sample laser pool 28 , the second spherical bellows metal valve 29, the fourth metal cold trap 30, the third spherical bellows metal valve 31, the fifth metal cold trap 32, the fourth spherical bellows metal valve 33, the KBr metal hot trap filled with KBr crystals 34. The fifth spherical bellows metal valve 35 , the sixth metal cold trap 36 and the sixth spherical bellows metal valve 37 . One end of the fourteenth 1/4inch metal valve 23 is welded and connected with the 1/2inch stainless steel pipeline 10 through the pipeline, and the other end of the fourteenth 1/4inch metal valve 23 is connected with the inlet of the third metal cold trap 24 through the pipeline, and the third The outlet of the metal cold trap 24 is connected to one end of the fifteenth 1/4inch metal valve 25 through a pipeline, and the other end of the fifteenth 1/4inch metal valve 25 is welded to the inlet end of the sample laser pool 28 through a 1/4inch stainless steel pipeline , the outlet end of the sample laser cell 28 is connected to one end of the second spherical bellows metal valve 29 through a 1/4 inch stainless steel pipeline. The CO ₂ infrared laser 26 is suspended above the sample laser pool 28 and is not directly connected. The imaging observation system 27 is integrated with the CO ₂ infrared laser 26 and moves synchronously. The other end of the second spherical bellows metal valve 29 is connected with the inlet of the fourth metal cold trap 30 through the pipeline, and the outlet of the fourth metal cold trap 30 is connected with one end of the third spherical bellows metal valve 31 through the pipeline, and the third spherical The other end of the metal bellows valve 31 is connected to the inlet end of the fifth metal cold trap 32 through a pipeline, and the outlet end of the fifth metal cold trap 32 is connected to one end of the fourth spherical bellows metal valve 33 through a pipeline, and the fourth spherical bellows The other end of the pipe metal valve 33 is connected with the inlet of the KBr metal heat well 34 filled with KBr crystals through pipelines, and the outlet of the KBr metal heat wells 34 filled with KBr crystals is connected with one end of the fifth spherical bellows metal valve 35 through pipelines. The other end of the five spherical bellows metal valve 35 is connected with the inlet end of the sixth metal cold trap 36 through a pipeline, and the outlet end of the sixth metal cold trap 36 is connected with one end of the sixth spherical bellows metal valve 37 through a pipeline.

The product collection/measurement system includes a capacitance vacuum gauge 38 , a seventh spherical bellows metal valve 39 , an eighth spherical bellows metal valve 40 , a 1/2 inch stainless steel collection tube 41 , a turbomolecular pump 43 , and an isotope mass spectrometer 44 . One end of the seventh spherical bellows metal valve 39 is connected to the other end of the sixth spherical bellows metal valve 37 through a pipeline, and the first capacitor vacuum gauge 38 is respectively connected to the sixth spherical bellows metal valve 37 and the seventh spherical bellows metal valve 37 through a tee. Pipe metal valve 39 is connected; the other end of the seventh spherical bellows metal valve 39 is respectively connected with the eighth spherical bellows metal valve 40, filling The 1/2inch stainless steel collection tube 41 of the molecular sieve and the dual-way system sampling end of the isotope mass spectrometer 44 are connected.

The vacuum system includes an ionization vacuum gauge 42 and a turbomolecular pump 43 with a rotary vane mechanical pump as the front stage. The inlet end of the turbomolecular pump 43 is connected with the other end of the first spherical bellows metal valve 22 through a pipeline, and the ionization vacuum gauge 42 is respectively connected with the intake end of the turbomolecular pump 43 and the other end of the first spherical bellows metal valve 22 through a tee.

The waste treatment system includes the first 1/4inch metal valve 1, the second 1/4inch metal valve 2, the rotary vane mechanical vacuum pump 3, the first metal cold trap 4, the third 1/4inch metal valve 5, the fourth 1/4inch Metal valve 6, the first bromine pentafluoride storage tank 7, the fifth 1/4inch metal valve 9, 1/2inch stainless steel pipe 10, the sixth 1/4inch metal valve 11, the seventh 1/4inch metal valve 12, the tenth Four 1/4inch metal valves 23, the third metal cold trap 24 and the fifteenth 1/4inch metal valve 25. One end of the first 1/4inch metal valve 1 is connected to the outlet of the first metal cold trap 4 through a horizontal pipeline, and the other end of the first 1/4inch metal valve 1 is connected to the waste liquid bucket in the fume hood outside the system through a pipeline. One end of the second 1/4inch metal valve 2 is connected to the horizontal pipeline through a tee, and the other end of the second 1/4inch metal valve 2 is connected to the intake end of the rotary vane mechanical vacuum pump 3 through a pipeline. The inlet of the first metal cold trap 4 is connected to one end of the third 1/4inch metal valve 5 through a pipeline, and the other end of the third 1/4inch metal valve 5 is connected to the 1/2inch stainless steel pipeline 10 by welding the 1/4inch stainless steel pipeline; One end of the fourth 1/4inch metal valve 6 is connected to the first bromine pentafluoride storage tank 7 through a 1/4inch stainless steel pipeline, and the other end of the fourth 1/4inch metal valve 6 is respectively connected to the third 1/4inch metal valve through a tee The valve 5 and the 1/2inch stainless steel pipe 10 are connected. The other end of the fifth 1/4inch metal valve 9 is connected to the 1/2inch stainless steel pipe 10 by welding. One end of the seventh 1/4inch metal valve 12 is welded to the 1/2inch stainless steel pipe 10 through a pipeline, and the other end of the seventh 1/4inch metal valve 12 is connected to one end of the sixth 1/4inch metal valve 11 through a pipeline, and the sixth The other end of the 1/4inch metal valve 11 is connected with the gas outlet port of the Ar gas cylinder outside the system through a pipeline. One end of the fourteenth 1/4inch metal valve 23 is connected to the 1/2inch stainless steel pipeline 10 through the welding of the pipeline, and the other end of the fourteenth 1/4inch metal valve 23 is connected with the inlet of the third metal cold trap 24 through the pipeline, and the third The outlet of the metal cold trap 24 is connected with one end of the fifteenth 1/4inch metal valve 25 through a pipeline.

The entire system pipeline and sample laser pool are all designed with 316 stainless steel, the inner wall of the pipeline has been specially polished, and all pipelines except the metal cold trap are wrapped with heating tape.

The metal valve is connected with the pipeline through a metal ferrule sealing method.

said Molecular sieve is filled in a stainless steel tube with an outer diameter of 1/2inch to form a filling The 1/2inch stainless steel collection tube 41 of molecular sieve, the 1/2inch stainless steel collection tube 41 collects oxygen by freezing with liquid nitrogen.

As shown in Figure 1, a method for analyzing the oxygen isotope composition of high-temperature refractory mineral laser-BrF ₅ method using the above-mentioned high-temperature refractory mineral laser-BrF ₅ method oxygen isotope composition analysis system, the method specifically includes the following steps:

Step 1. Load the high-temperature refractory mineral sample to be analyzed into the analysis system

Remove the _CO2 infrared laser 26 and imaging observation system 27 from directly above the sample laser pool 28, close all valves in the analysis system, open the sample laser pool 28, and put the high-temperature refractory mineral sample to be analyzed into a clean Make records in the sample tray, place the sample tray containing the high-temperature refractory mineral samples to be analyzed in the sample laser pool 28, close and tighten the sample laser pool 28, and complete the sample loading operation.

Step 2. Baking and vacuuming the entire analysis system to remove gas

Turn on the power supply of the heating belt, and heat and bake the analysis system at 250°C. The entire analysis system is heated and baked with a wound heating belt, and the baking temperature is 250°C.

Put the liquid nitrogen cup on the outer cover of the first metal cold trap 4, slowly open the fifteenth 1/4inch metal valve 25 and the fourteenth 1/4inch metal valve 23, first part of the air in the sample laser pool 28 ("part of the air") About one-fifth of the total gas in the sample laser cell) diffuses into the 1/2inch stainless steel pipe main pipe 10; close the fifteenth 1/4inch metal valve 25, open the third 1/4inch metal valve 5 and the second 1 /4inch metal valve 2, through the rotary vane mechanical vacuum pump 3, pump 1/2inch stainless steel pipe 10 to low vacuum (because the air volume is very small, it only takes more than ten seconds to pump, and this step does not require high vacuum degree), close the second Fourteen 1/4inch metal valves 23 and third 1/4inch metal valves 5 . Slowly open the fifteenth 1/4inch metal valve 25, and diffuse the air in the sample laser pool 28 into the 1/2inch stainless steel pipe 10 in stages (take out most of the gas in the sample laser pool in five times) and pass through the rotary The chip mechanical vacuum pump 3 draws a low vacuum (because the air volume is very small, it can be pumped for more than ten seconds, and the operation of this step does not require a high degree of vacuum), and finally fully open the fifteenth 1/4inch metal valve 25, the fourteenth 1 /4inch metal valve 23, tenth 1/4inch metal valve 16 and twelfth 1/4inch metal valve 19. Open the third 1/4inch metal valve 5 and the second 1/4inch metal valve 2 to pump the sample in the laser pool 28 to a low vacuum of 10 ⁻¹ Pa for 20 minutes, then close the third 1/4inch metal valve 5; in the second metal cold trap 21 Put the liquid nitrogen cup on the jacket, open the first spherical bellows metal valve 22, the third spherical bellows metal valve 31, the fourth spherical bellows metal valve 33, the fifth spherical bellows metal valve 35, the sixth spherical bellows metal valve The valve 37, the seventh spherical bellows metal valve 39 and the eighth spherical bellows metal valve 40 are connected to the turbomolecular pump 43 to draw a high vacuum for the system, and the vacuum degree of the system is monitored by the ionization vacuum gauge 42. After the vacuum degree reaches 10 ^-6 Pa Continue vacuuming for 30 minutes.

Step 3. Pre-fluoridate the high-temperature refractory mineral sample in the sample laser pool 28

After the vacuum reaches the requirement, turn off the power supply of the heating belt, wait for the analysis system to return to room temperature, put a liquid nitrogen cup on the third metal cold trap 24 and the first bromine pentafluoride storage tank 7; close the tenth 1/4inch metal valve 16 , the twelfth 1/4inch metal valve 19, the fourteenth 1/4inch metal valve 23, the fifteenth 1/4inch metal valve 25 and the thirteenth 1/4inch metal valve 20, open the third bromine pentafluoride storage tank After the eleventh 1/4inch metal valve 17 above 18, slowly and half-open the twelfth 1/4inch metal valve 19, the pressure of the BrF ₅ reagent diffused into the 1/2inch stainless steel pipe main pipeline 10 controlled by the vacuum pressure gauge 8 is 0.02MPa, close the twelfth 1/4inch metal valve 19; open the fourteenth 1/4inch metal valve 23, the BrF ₅ in the 1/2inch stainless steel pipe main pipeline 10 is frozen into the third metal cold trap 24, close the tenth Four 1/4inch metal valves 23, remove the liquid nitrogen cup outside the third metal cold trap 24, after the third metal cold trap 24 naturally thaws and returns to room temperature; open the fifteenth 1/4inch metal valve 25, and BrF ₅ reagent After diffusing into the sample laser pool 28 and keeping it for 2 minutes, open the fourteenth 1/4inch metal valve 23 and the fourth 1/4inch metal valve ₆ in turn, freeze the residual BrF5 reagent into the first bromine pentafluoride storage tank 7, Open the third 1/4inch metal valve 5 and the second 1/4inch metal valve 2, and the residual reactants that cannot be frozen are sucked away by the rotary vane mechanical vacuum pump 3 after being frozen by the first metal cold trap 4, and the first five The fourth 1/4inch metal valve 6 on the bromine fluoride storage tank 7.

Repeat the above method three times to carry out fluorination treatment on the sample and the inner wall of the sample laser pool 28. The last BrF ₅ reagent can be kept in the sample laser pool 28 for 2 hours, which can completely remove the high-temperature refractory mineral sample and the adsorption on the inner wall of the sample laser pool 28. of water vapor.

Step 4. Perform fluorination reaction on the high-temperature refractory mineral sample in the sample laser pool 28—O isotope extraction

After the high-temperature refractory mineral sample in the sample laser cell 28 is pre-fluorinated, the analysis system is pumped to a high vacuum of 10 ⁻⁶ Pa and then pumped for 30 minutes, and all valves are closed. Put a liquid nitrogen cup on the third metal cold trap 24 coat, open the eleventh 1/4inch metal valve 17 on the third bromine pentafluoride storage tank 18, after opening the fifth 1/4inch metal valve 9, slowly and half-open the second Twelve 1/4inch metal valves 19, through the vacuum pressure gauge 8 to control the diffusion of 0.01MPa BrF ₅ reagent that has been purified many times into the main pipeline 10 of 1/2inch stainless steel pipe, close the eleventh 1/4inch metal valve 17 and the tenth Two 1/4inch metal valve 19; open the fourteenth 1/4inch metal valve 23 and freeze the BrF ₅ reagent in the pipeline to the third metal cold trap 24, close the fourteenth 1/4inch metal valve 23; remove the third metal The liquid nitrogen cup outside the cold trap 24 returns to room temperature, opens the fifteenth 1/4inch metal valve 25 to diffuse the BrF ₅ reagent into the sample laser pool 28, closes the fifteenth ₁ /4inch metal valve 25; 26 is adjusted to the top of the sample laser pool 28, positioned directly above the high-temperature refractory mineral sample to be analyzed through the imaging observation system 27, and the laser beam of the _CO2 infrared laser 26 is guided to the sample hole containing the high-temperature refractory mineral sample to be analyzed , according to the needs of high-temperature refractory mineral samples, adjust the CO ₂ infrared laser 26 laser spot size and laser energy, heat the high-temperature refractory mineral samples to be analyzed until "white heat", and conduct high-temperature refractory mineral samples with BrF ₅ reagent at high temperature The reaction releases oxygen and completes the extraction of O isotopes from the sample.

For example, for olivine particle samples, due to its high formation temperature and refractory properties, the laser spot diameter can be adjusted to 125um, and the continuous excitation mode is used, and the laser energy is slowly increased to 20W, and the "white heat" phenomenon of olivine minerals can be seen.

Step 5. Purification, collection and mass spectrometry of _O2

In the 4th metal cold trap 30, the 5th metal cold trap 32, the 6th metal cold trap 36 and filling The 1/2inch stainless steel collection pipe 41 of the molecular sieve is covered with a liquid nitrogen cup, and the second spherical bellows metal valve 29 is slowly opened to freeze the reactant in the laser pool 28 and the remaining _BrF5 reagent into the fourth metal cold trap 30; Open the third spherical bellows metal valve 31 after 10 minutes, and freeze the reactant and residual BrF ₅ reagent through the fifth metal cold trap 32; open the fourth spherical bellows metal valve 33 after 5 minutes, and pass through the KBr metal hot trap 34 pairs The reactants and residual BrF5 reagents are further absorbed; after ₅ minutes, the fifth spherical bellows metal valve 35 is opened, and the generated _O2 is further frozen and purified by the sixth metal cold trap 36; after 5 minutes, the sixth spherical bellows metal valve 37 is opened , monitor the reaction to generate O ₂ pressure through capacitance vacuum gauge 38; open the seventh spherical bellows metal valve 39, O ₂ is collected to fill with In the 1/2inch stainless steel collecting pipe 41 of the molecular sieve, monitor the situation that _O2 is collected by a capacitance vacuum gauge 38, and close the seventh spherical bellows metal valve 39 after the _O2 is completely collected; The liquid nitrogen outside the 1/2 inch stainless steel collection tube 41 of the molecular sieve, O ₂ is released after returning to room temperature, and the released O ₂ is introduced into the isotope mass spectrometer 44 for isotope determination.

Step 6. Waste collection and treatment

After the O isotope determination of the sample is completed, the residual BrF ₅ reagent and reaction products adsorbed in each cold trap need to be harmlessly treated.

Put a liquid nitrogen cup on the first metal cold trap 4, the first bromine pentafluoride storage tank 7 and the third metal cold trap 24, close the sixth spherical bellows metal valve 37, open the third 1/4inch metal valve 5, Fourteenth 1/4inch metal valve 23, fifteenth 1/4inch metal valve 25, second spherical bellows metal valve 29, third spherical bellows metal valve 31, fourth spherical bellows metal valve 33 and fifth spherical Bellows metal valve 35, the residual _BrF5 reagent and reactant in the system pass through the first metal cold trap 4, the third metal cold trap 24, the fourth metal cold trap 30, the fifth metal cold trap 32, the sixth metal cold trap After the well 36 is fully frozen; slowly open the second 1/4inch metal valve 2 and pump out the impurity gas that cannot be frozen by liquid nitrogen through the rotary vane mechanical vacuum pump 3, close the third 1/4inch metal valve 5 and the fourth spherical bellows Metal valve 33 and the 5th spherical bellows metal valve 35; Remove the liquid nitrogen cup outside the 3rd metal cold trap 24, the 4th metal cold trap 30, the 5th metal cold trap 32 and the 6th metal cold trap 36, wait for cold trap After returning to room temperature, open the fourth 1/4inch metal valve 6 to put the first metal cold trap 4, the third metal cold trap 24, the fourth metal cold trap 30, the fifth metal cold trap 32, and the sixth metal cold trap 36 The frozen residual BrF ₅ reagent and reaction product are frozen into the first bromine pentafluoride storage tank 7; close the fourth 1/4inch metal valve 6, open the third 1/4inch metal valve 5, and the fourth spherical bellows metal valve 33 and the fifth spherical bellows metal valve 35, the system pipeline is further evacuated to 10 ⁻¹ Pa through the rotary vane mechanical vacuum pump 3, and the possible residual impurities in the analysis system are frozen in the first metal cold trap 4; close For all valves, remove the liquid nitrogen cup outside the first metal cold trap 4, open the sixth 1/4inch metal valve 11, the seventh 1/4inch metal valve 12, the third 1/4inch metal valve 5 and the first 1/4inch metal valve in sequence. The 4inch metal valve 1 carries the possible residual waste gas into the lime bucket in the fume hood with Ar gas to complete waste disposal and avoid environmental pollution.

The present invention has been described in detail above in conjunction with the accompanying drawings and embodiments, but the present invention is not limited to the above-mentioned embodiments, and can also be made without departing from the gist of the present invention within the scope of knowledge possessed by those of ordinary skill in the art. kind of change. The content that is not described in detail in the present invention can adopt the prior art.

Claims (23)

1. A high-temperature refractory mineral laser _- BrF method oxygen isotope composition analysis system is characterized in that: the system includes reagent purification system, sample reaction/separation/purification system, product collection/determination system and vacuum system; reagent purification system Connect to one end of the sample reaction/separation/purification system and the vacuum system respectively, the other end of the sample reaction/separation/purification system is connected to one end of the product collection/measurement system, and the other end of the product collection/measurement system is connected to the vacuum system. 2. A kind of high-temperature refractory mineral laser _- BrF method oxygen isotope composition analysis system according to claim 1, is characterized in that: described reagent purification system comprises rotary vane mechanical vacuum pump (3), the first metal cooling Well (4), the first bromine pentafluoride storage tank (7), vacuum pressure gauge (8), 1/2inch stainless steel pipe (10), the second bromine pentafluoride storage tank (15), the third bromine pentafluoride Bromine storage tank (18), the second metal cold trap (21), the top of 1/2inch stainless steel pipe (10) is provided with vacuum pressure gauge (8), one side upper part of 1/2inch stainless steel pipe (10) is respectively connected with The top outlet of the first bromine pentafluoride storage tank (7) is connected to the inlet of the first metal cold trap (4), and the outlet of the first metal cold trap (4) is connected to the inlet end of the rotary vane mechanical vacuum pump (3); 1/ The bottom of one side of the 2inch stainless steel pipe (10) is respectively connected with the second bromine pentafluoride storage tank (15) and the top outlet of the third bromine pentafluoride storage tank (18), and the other side of the 1/2inch stainless steel pipe (10) The upper part of the side is connected with the inlet of the second metal cold trap (21). 3. A kind of high-temperature refractory mineral laser-BrF ₅ method oxygen isotope composition analysis system according to claim 2, is characterized in that: the top of described 1/2inch stainless steel pipeline (10) and vacuum pressure gauge (8) A fifth 1/4inch metal valve (9) is provided between them. 4. a kind of high-temperature refractory mineral laser _- BrF method oxygen isotope composition analysis system according to claim 3 is characterized in that: described 1/2inch stainless steel pipeline (10) and the first bromine pentafluoride storage tank A fourth 1/4inch metal valve (6) is provided between (7), and a third 1/4inch metal valve (5) is provided between the 1/2inch stainless steel pipe (10) and the inlet of the first metal cold trap (4). A second 1/4inch metal valve (2) is provided between the outlet of the first metal cold trap (4) and the inlet end of the rotary vane mechanical vacuum pump (3), and a second metal valve (2) is provided at the outlet of the first metal cold trap (4). The first 1/4inch metal valve (1) in parallel with the second 1/4inch metal valve (2). 5. A kind of high-temperature refractory mineral laser-BrF ₅ method oxygen isotope composition analysis system according to claim 4, is characterized in that: described 1/2inch stainless steel pipeline (10) bottom and the 3rd bromine pentafluoride storage The twelfth 1/4inch metal valve (19), the eleventh 1/4inch metal valve (17), the twelfth 1/4inch metal valve (19), the eleventh 1 The tenth 1/4inch metal valve (16), the ninth 1/4inch metal valve (14), the tenth 1 An eighth 1/4inch metal valve (13) connected to both the /4inch metal valve (16) and the ninth 1/4inch metal valve (14) is provided. 6. A high-temperature refractory mineral laser-BrF ₅ method oxygen isotope composition analysis system according to claim 5, characterized in that: the middle part of one side of the 1/2inch stainless steel pipeline (10) is also connected with the seventh 1 One end of the /4inch metal valve (12) is connected, and the other end of the seventh 1/4inch metal valve (12) is connected with the sixth 1/4inch metal valve (11). 7. A kind of high-temperature refractory mineral laser _- BrF method oxygen isotope composition analysis system according to claim 6, is characterized in that: the other side of described 1/2inch stainless steel pipeline (10) and the second metal cooling A thirteenth 1/4inch metal valve (20) is provided between the inlets of the wells (21) to connect, and the outlet of the second metal cold trap (21) is provided with a first spherical bellows metal valve (22), and the first spherical bellows Metal valve (22) is connected with vacuum system. 8. A kind of high-temperature refractory mineral laser _- BrF method oxygen isotope composition analysis system according to claim 7, is characterized in that: described sample reaction/separation/purification system comprises the 3rd metal cold trap (24), CO ₂ infrared laser (26), imaging observation system (27), sample laser pool (28), fourth metal cold trap (30), fifth metal cold trap (32), KBr metal heat trap (34) and sixth Metal cold trap (36), the inlet of the third metal cold trap (24) is connected to the thirteenth 1/4inch metal valve (20) of the reagent purification system, the outlet of the third metal cold trap (24) is connected to the sample laser pool (28) One end of the sample laser pool (28) is connected to the inlet port of the fourth metal cold trap (30), and the outlet port of the fourth metal cold trap (30) is connected to the inlet port of the fifth metal cold trap (32). Connect, the outlet port of the fifth metal cold trap (32) is connected with the inlet port of KBr metal hot trap (34), and the outlet port of KBr metal hot trap (34) is connected with the inlet port of the sixth metal cold trap (36), The outlet end of the sixth metal cold trap (36) is connected with the product collection/measurement system; _CO2 infrared laser (26) is provided on the sample laser pool (28), and the imaging observation system (26) is provided on the _CO2 infrared laser (26). 27). 9. A kind of high-temperature refractory mineral laser _- BrF method oxygen isotope composition analysis system according to claim 8, is characterized in that: described third metal cold trap (24) inlet and 1/2inch stainless steel pipeline (10 ) between the 14th 1/4inch metal valve (23), the 15th 1/4inch metal valve (25) between the outlet of the third metal cold trap (24) and the sample laser pool (28), the sample A second spherical bellows metal valve (29) is arranged between the laser pool (28) and the fourth metal cold trap (30), and three metal valves (29) are arranged between the fourth metal cold trap (30) and the fifth metal cold trap (32). A spherical bellows metal valve (31), a fourth spherical bellows metal valve (33) is arranged between the fifth metal cold trap (32) and the KBr metal heat trap (34), the KBr metal heat trap (34) and the sixth A fifth spherical bellows metal valve (35) is arranged between the metal cold traps (36), and a sixth spherical bellows metal valve (37) is arranged between the sixth metal cold trap (36) and the product collection/measurement system. 10. A kind of high-temperature refractory mineral laser _- BrF method oxygen isotope composition analysis system according to claim 9, is characterized in that: described product collection/measurement system comprises capacitance vacuum gauge (38), the seventh spherical corrugated Tube metal valve (39), eighth spherical bellows metal valve (40), 1/2inch stainless steel collection tube (41), turbomolecular pump (43), isotope mass spectrometer (44), seventh spherical bellows metal valve ( One end of 39) is connected to the sixth spherical bellows metal valve (37) of the sample reaction/separation/purification system through a pipeline, and the capacitance vacuum gauge (38) is connected to the sixth spherical bellows metal valve (37) and the seventh spherical bellows metal valve (37) respectively. The tube metal valve (39) is connected; the other end of the seventh spherical bellows metal valve (39) is respectively connected with the eighth spherical bellows metal valve (40), 1/2inch stainless steel collection pipe (41) and isotope mass spectrometer (44) connect. 11. A kind of high-temperature refractory mineral laser _- BrF method oxygen isotope composition analysis system according to claim 10, is characterized in that: described vacuum system comprises ionization vacuum gauge (42) and with rotary vane mechanical pump as The turbomolecular pump (43) of the front stage, the turbomolecular pump (43) is connected with the first spherical bellows metal valve (22) of the reagent purification system, and the ionization vacuum gauge (42) is respectively connected with the turbomolecular pump (43), the first Spherical bellows metal valve (22) is connected. 12. A high-temperature refractory mineral laser-BrF ₅ method oxygen isotope composition analysis system according to claim 11, characterized in that: the analysis system also includes a waste treatment system, and the waste treatment system includes the first 1/4inch Metal valve (1), second 1/4inch metal valve (2), rotary vane mechanical vacuum pump (3), first metal cold trap (4), third 1/4inch metal valve (5), fourth 1/4inch 4inch metal valve (6), the first bromine pentafluoride storage tank (7), the fifth 1/4inch metal valve (9), 1/2inch stainless steel pipe (10), the sixth 1/4inch metal valve (11), The seventh 1/4inch metal valve (12), the fourteenth 1/4inch metal valve (23), the third metal cold trap (24) and the fifteenth 1/4inch metal valve (25), the first 1/4inch metal valve One end of the valve (1) is connected to the outlet of the first metal cold trap (4), one end of the second 1/4inch metal valve (2) is connected to the first 1/4inch metal valve (1), the first metal cold trap (4) The outlet connection of the second 1/4inch metal valve (2) is connected to the inlet end of the rotary vane mechanical vacuum pump (3); the inlet of the first metal cold trap (4) is connected to the third 1/4inch metal valve ( 5), the other end of the third 1/4inch metal valve (5) is connected to the 1/2inch stainless steel pipe (10); one end of the fourth 1/4inch metal valve (6) is connected to the first bromine pentafluoride storage The tank (7) is connected, and the other end of the fourth 1/4inch metal valve (6) is connected with the third 1/4inch metal valve (5) and 1/2inch stainless steel pipe (10) respectively; the fifth 1/4inch metal valve ( The other end of 9) is connected with 1/2inch stainless steel pipe (10); one end of the seventh 1/4inch metal valve (12) is connected with 1/2inch stainless steel pipe (10), and the seventh 1/4inch metal valve (12) The other end is connected with one end of the sixth 1/4inch metal valve (11); one end of the fourteenth 1/4inch metal valve (23) is connected with the 1/2inch stainless steel pipeline (10), and the fourteenth 1/4inch metal valve ( The other end of 23) is connected with the inlet of the third metal cold trap (24), and the outlet of the third metal cold trap (24) is connected with one end of the fifteenth 1/4inch metal valve (25). 13. A method for analyzing the oxygen isotope composition of high-temperature refractory mineral laser-BrF ₅ method using the high-temperature refractory mineral laser-BrF ₅ method oxygen isotope composition analysis system described in claims 1 to 12 above, characterized in that the The method specifically includes the following steps: Step 1. Load the high-temperature refractory mineral sample to be analyzed into the analysis system; Step 2. Baking and vacuuming the entire analysis system to remove gas; Step 3, pre-fluorinating the high-temperature refractory mineral sample in the sample laser pool; Step 4, performing fluorination reaction-O isotope extraction on the high-temperature refractory mineral sample in the sample laser pool; Step ₅ , O purification, collection and mass spectrometry; Step 6, waste collection and treatment. 14. the method for high-temperature refractory mineral laser _- BrF method oxygen isotope composition analysis according to claim 13, is characterized in that, the concrete steps of described step 1 are as follows: CO ₂ Infrared laser (26) and imaging observation system (27) are removed from directly above the sample laser pool (28), all valves in the analysis system are closed, the sample laser pool (28) is opened, and the high temperature to be analyzed Put the refractory mineral sample into a clean sample tray and make a record, place the sample tray containing the high-temperature refractory mineral sample to be analyzed in the sample laser pool (28), close and tighten the sample laser pool (28), and complete Sample loading operation. 15. the method for high-temperature refractory mineral laser _- BrF method oxygen isotope composition analysis according to claim 14, is characterized in that, the specific steps of described step 2 are as follows: Turn on the power supply of the heating belt to heat and bake the analysis system; put a liquid nitrogen cup on the first metal cold trap (4), open the fifteenth 1/4inch metal valve (25) and the fourteenth 1/4inch metal valve (23), first diffuse part of the air in the sample laser pool (28) into the 1/2inch stainless steel pipe main pipe (10); close the fifteenth 1/4inch metal valve (25), open the third 1/4inch metal valve The valve (5) and the second 1/4inch metal valve (2) draw a low vacuum in the 1/2inch stainless steel pipe (10) through the rotary vane mechanical vacuum pump (3), and close the fourteenth 1/4inch metal valve (23) and a third 1/4inch metal valve (5). Slowly open the fifteenth 1/4inch metal valve (25), diffuse the air in the sample laser cell (28) into the 1/2inch stainless steel pipe (10) and draw a low vacuum through the rotary vane mechanical vacuum pump (3) , finally fully open the fifteenth 1/4inch metal valve (25), the fourteenth 1/4inch metal valve (23), the tenth 1/4inch metal valve (16) and the twelfth 1/4inch metal valve (19) ; Open the third 1/4inch metal valve (5) and the second 1/4inch metal valve (2) after sample low vacuum 20min in the sample laser pool (28), close the third 1/4inch metal valve (5); The second metal cold trap (21) is covered with a liquid nitrogen cup, and the first spherical bellows metal valve (22), the third spherical bellows metal valve (31), the fourth spherical bellows metal valve (33), and the fifth spherical bellows metal valve are opened. The spherical bellows metal valve (35), the sixth spherical bellows metal valve (37), the seventh spherical bellows metal valve (39) and the eighth spherical bellows metal valve (40) are connected to the turbomolecular pump (43) as After the system is evacuated to a high vacuum, continue to evacuate for 30 minutes, and monitor the system vacuum through an ionization vacuum gauge (42). 16. the method for high-temperature refractory mineral laser _- BrF method oxygen isotope composition analysis according to claim 15, is characterized in that: the system heating baking temperature in described step 2 is 250 ℃; ) to pump a high vacuum for the system to a vacuum degree of 10 ^-6 Pa. 17. the method for high-temperature refractory mineral laser _- BrF method oxygen isotope composition analysis according to claim 16, is characterized in that, the specific steps of described step 3 are as follows: Turn off the heating band power supply, treat that the analysis system returns to room temperature, put a liquid nitrogen cup on the third metal cold trap (24) and the first bromine pentafluoride storage tank (7) coat; close the tenth 1/4inch metal valve (16 ), the twelfth 1/4inch metal valve (19), the fourteenth 1/4inch metal valve (23), the fifteenth 1/4inch metal valve (25) and the thirteenth 1/4inch metal valve (20), After opening the eleventh 1/4inch metal valve (17) above the third bromine pentafluoride storage tank (18), slowly and half-open the twelfth 1/4inch metal valve (19), controlled by the vacuum pressure gauge (8) Diffuse to the BrF ₅ reagent pressure in the 1/2inch stainless steel pipe main pipe (10), close the twelfth 1/4inch metal valve (19); open the 14th 1/4inch metal valve (23) and then 1/2inch stainless steel pipe BrF5 in the main pipeline ( ₁₀ ) freezes in the third metal cold trap (24), closes the fourteenth 1/4inch metal valve (23), removes the liquid nitrogen cup outside the third metal cold trap (24), After the third metal cold trap (24) thaws naturally and returns to room temperature; open the fifteenth 1/4inch metal valve ( ₂₅ ), diffuse the BrF5 reagent into the sample laser pool (28) and keep it for 2min, then open the fourteenth trap in turn. 1/4inch metal valve (23), the fourth 1/4inch metal valve (6), freeze the residual BrF ₅ reagent in the first bromine pentafluoride storage tank (7), open the third 1/4inch metal valve (5 ) and the second 1/4inch metal valve (2), after the residual reactant that cannot be frozen is frozen by the first metal cold trap (4), it is sucked away by the rotary vane mechanical vacuum pump (3), and the first pentafluoride The fourth 1/4inch metal valve (6) on the bromine storage tank (7). 18. The method for oxygen isotope composition analysis of high-temperature refractory mineral laser-BrF ₅ method according to claim 17, characterized in that: in the step 3, the vacuum pressure gauge (8) controls the diffusion to the main 1/2inch stainless steel pipe The BrF5 reagent pressure in pipeline ( ₁₀ ) is 0.02MPa. 19. the method for high-temperature refractory mineral laser _- BrF method oxygen isotope composition analysis according to claim 18, is characterized in that: repeat three times by the method for above-mentioned step 3, carry out sample and inner wall in sample laser pool (28) For fluorination treatment, the last BrF ₅ reagent is kept in the sample laser cell (28) for 2 hours to completely remove the high-temperature refractory mineral sample and the water vapor adsorbed on the inner wall of the sample laser cell (28). 20. the method for high-temperature refractory mineral laser _- BrF method oxygen isotope composition analysis according to claim 19, is characterized in that, the specific steps of described step 4 are as follows: After the high-temperature refractory mineral sample in the sample laser pool (28) has completed the pre-fluorination treatment, the analysis system is evacuated to a high vacuum of 10 ^-6 Pa and then continued for 30 minutes, and all valves are closed; in the third metal cold trap (24) Put the liquid nitrogen cup on the coat, open the eleventh 1/4inch metal valve (17) on the third bromine pentafluoride storage tank (18), open the fifth 1/4inch metal valve (9), slowly and half open the tenth Two 1/4inch metal valves (19), through the vacuum pressure gauge (8) control the 0.01MPa diffusion of BrF ₅ reagent through repeated purification into the 1/2inch stainless steel pipe main pipeline (10), and close the eleventh 1/4inch metal valve Valve (17) and the twelfth 1/4inch metal valve (19); open the fourteenth 1/4inch metal valve (23) and freeze the _BrF5 reagent in the pipeline to the third metal cold trap (24), close the 14th metal cold trap (24) Fourteen 1/4inch metal valves (23); remove the liquid nitrogen cup outside the third metal cold trap (24) to return to room temperature, open the fifteenth 1/4inch metal valve (25) to diffuse the BrF ₅ reagent to the sample laser pool In (28), close the fifteenth 1/4inch metal valve (25); adjust the CO ₂ infrared laser (26) to the top of the sample laser pool (28), and locate the high temperature difficult to be analyzed through the imaging observation system (27). Directly above the molten ore sample, the laser beam of the CO ₂ infrared laser (26) is guided into the sample hole of the high-temperature refractory mineral sample to be analyzed, and the laser spot size and laser energy of the CO ₂ infrared laser (26) are adjusted for analysis. The high-temperature refractory mineral sample is heated, and the high-temperature refractory mineral sample reacts with the BrF ₅ reagent at high temperature to release oxygen, and the O isotope extraction of the sample is completed. 21. the method for high-temperature refractory mineral laser _- BrF method oxygen isotope composition analysis according to claim 20, is characterized in that, the specific steps of described step 5 are as follows: Put a liquid nitrogen cup on the fourth metal cold trap (30), the fifth metal cold trap (32), the sixth metal cold trap (36) and the 1/2inch stainless steel collection tube (41), and slowly open the second spherical bellows Metal valve (29), the reactant in the laser cell (28) and residual BrF5 reagent are frozen in the _4th metal cold trap (30); Open the 3rd spherical bellows metal valve (31) after 10min, pass through the 4th metal cold trap (30) Five metal cold traps (32) freeze the reactant and the remaining BrF5 reagent again; after _5min , the fourth spherical bellows metal valve (33) is opened, and the reactant and the residual _BrF5 reagent are cooled by the KBr metal hot trap (34). Absorb further; Open the 5th spherical bellows metal valve (35) after 5min, by the 6th metal cold trap (36) to the O further freeze purification _; Open the 6th spherical bellows metal valve (37) after 5min, pass The capacitance vacuum gauge (38) monitors the reaction to generate O ₂ pressure; open the seventh spherical bellows metal valve (39 ₎ , O is collected into the filling In the 1/2inch stainless steel collecting pipe (41) of the molecular sieve, monitor the situation that _O2 is collected by a capacitance vacuum gauge (38), and close the seventh spherical bellows metal valve (39) after _O2 is completely collected; remove 1/ The liquid nitrogen outside the 2inch stainless steel collection tube (41) returns to room temperature after O ₂ is released, and the released O ₂ is introduced into the isotope mass spectrometer (44) for isotope determination. 22. the method for high-temperature refractory mineral laser _- BrF method oxygen isotope composition analysis according to claim 21, is characterized in that: the 1/2inch stainless steel collecting pipe (41) in the described step 5 is filled with Molecular sieve. 23. _The method for analyzing the oxygen isotope composition of high-temperature refractory mineral laser-BrF method according to claim 22, characterized in that: the specific steps of the described step 6 are as follows: Put the liquid nitrogen cup on the first metal cold trap (4), the first bromine pentafluoride storage tank (7) and the third metal cold trap (24), close the sixth spherical bellows metal valve (37), open the first Three 1/4inch metal valves (5), fourteenth 1/4inch metal valves (23), fifteenth 1/4inch metal valves (25), second spherical bellows metal valves (29), third spherical bellows Metal valve (31), the fourth spherical bellows metal valve (33) and the _fifth spherical bellows metal valve (35), the residual BrF5 reagent and reactant in the system pass through the first metal cold trap (4), the second After the three metal cold traps (24), the fourth metal cold trap (30), the fifth metal cold trap (32), and the sixth metal cold trap (36) are fully frozen; slowly open the second 1/4inch metal valve (2 ) through the rotary vane mechanical vacuum pump (3) to remove impurity gases that cannot be frozen by liquid nitrogen, and close the third 1/4inch metal valve (5), the fourth spherical bellows metal valve (33) and the fifth spherical bellows metal Valve (35); remove the liquid nitrogen cup outside the third metal cold trap (24), the fourth metal cold trap (30), the fifth metal cold trap (32) and the sixth metal cold trap (36), and wait for the cold trap After returning to room temperature, open the 4th 1/4inch metal valve (6) with the first metal cold trap (4), the 3rd metal cold trap (24), the 4th metal cold trap (30), the 5th metal cold trap ( 32), the residual _BrF5 reagent and the reaction product frozen in the sixth metal cold trap (36) are frozen in the first bromine pentafluoride storage tank (7); close the fourth 1/4inch metal valve (6), open the first The three 1/4inch metal valves (5), the fourth spherical bellows metal valve (33) and the fifth spherical bellows metal valve (35) further evacuate the system pipeline through the rotary vane mechanical vacuum pump (3), and the The remaining impurities in the analysis system are frozen in the first metal cold trap (4); all valves are closed, the liquid nitrogen cup outside the first metal cold trap (4) is removed, and the sixth 1/4inch metal valve (11 ), the seventh 1/4inch metal valve (12), the third 1/4inch metal valve (5) and the first 1/4inch metal valve (1), carry the residual waste gas to the lime in the fume hood with Ar gas bucket, complete waste disposal.