WO2024041037A1 - Efficient fluidizing chlorination method for carbide slag - Google Patents

Abstract

Disclosed is an efficient fluidizing chlorination method for carbide slag. The method comprises the following steps: setting chlorination conditions of a primary fluidizing chlorination furnace and a secondary fluidizing chlorination furnace on the basis of the content of TiC in the carbide slag, and introducing a high-concentration mixed gas into the secondary fluidizing chlorination furnace, wherein the primary fluidizing chlorination furnace and the secondary fluidizing chlorination furnace are connected in series; adding the carbide slag into the primary fluidizing chlorination furnace for a primary chlorination reaction; and discharging the primarily chlorinated carbide slag into the secondary fluidizing chlorination furnace for a deep chlorination reaction, discharging tailings after the reaction, subjecting the residual gas in the secondary fluidizing chlorination furnace to cyclone dust removal, and then introducing the residual gas into the primary fluidizing chlorination furnace. By means of serially arranging the two fluidizing chlorinations, the method of the present invention achieves the contact reaction between the high-concentration Cl2 and the inactive carbide slag and the reaction between the low-concentration Cl2 and TiC on the surface layer of new carbide slag, thereby increasing the utilization rate of chlorine, greatly reducing the alkali consumption, improving the cost-efficiency of titanium tetrachloride production, and improving the chlorination rate and efficiency of the carbide slag and the comprehensive chlorination effects.

Description

An efficient boiling chlorination method for carbonized slag Technical field

The invention relates to the technical field of chemical engineering, and in particular to an efficient boiling chlorination method of carbonized slag.

Background technique

Vanadium-titanium magnetite reserves are abundant in the world, and my country's reserves are among the best. The Panxi region has reserves of tens of billions of tons, and the total titanium resource reserves rank first in the country. Vanadium-titanium magnetite is a multi-element symbiotic ore containing 30-34Wt% of iron (existing in the form of iron oxide in the ore). It is mainly used as a raw material for extracting iron, vanadium and titanium.

The vanadium-ilmenite concentrate produced in the Panxi area contains a certain amount of TiO _2. After smelting in the blast furnace, it enters the blast furnace slag and is discarded. It is not fully utilized, which greatly affects the comprehensive titanium resources in the vanadium-titanium magnetite in the Panxi area. usage efficiency.

The existing process of "carbonizing blast furnace slag at high temperature and selective chlorination at low temperature to generate TiCl ₄ " can effectively extract Ti from blast furnace slag. At present, the thermal reduction treatment of blast furnace slag is running stably, and the TiO ₂ reduction rate in the slag is stably controlled at more than 85%, which is good. The low-temperature selective chlorination process adopts single-stage boiling chlorination. In order to maintain effective chlorination of the effective component TiC in the carbonized slag, there is excessive chlorine in the furnace, resulting in low chlorine utilization and high chlorine consumption. In addition, excessive chlorine requires the use of alkali solution absorption, resulting in high alkali consumption; at the same time, the chlorination efficiency of TiC in the carbonized slag is also low, and it is difficult to stably reach more than 85%, which seriously affects the Ti utilization efficiency in the blast furnace and the economy of the entire process.

Therefore, there is a need in the prior art for improving the efficient boiling chlorination method of carbonized slag.

Contents of the invention

In view of this, the purpose of the embodiments of the present invention is to propose an efficient boiling chlorination method for carbonized slag. In order to solve the problems of low low-temperature selective chlorination efficiency of existing carbonized slag and high chlorine gas consumption, the use of two-stage boiling chlorination not only improves the chlorine gas utilization efficiency, but also improves the carbonized slag after two-stage chlorination. The chlorination rate can effectively improve the utilization rate of titanium element and chlorination in carbonized slag and improve the comprehensive chlorination effect.

Based on the above objectives, embodiments of the present invention provide an efficient boiling chlorination method, which method includes:

The chlorination conditions of the first-level boiling chlorination furnace and the second-level boiling chlorination furnace are set based on the TiC content in the carbonized slag, and a high-concentration mixed gas is introduced into the second-level boiling chlorination furnace. Stage boiling chlorination furnaces are connected in series;

Add the carbonized slag to the first-stage boiling chlorination furnace for preliminary chlorination reaction;

The carbonized slag after the preliminary chlorination reaction is discharged into the second-level boiling chlorination furnace for deep chlorination reaction. After the reaction, the tailings are discharged. The remaining gas in the second-level boiling chlorination furnace is passed into the first-level boiling chlorination furnace after cyclone dust removal. .

In some embodiments, the two-stage boiling chlorination furnace is the main reactor, and 55% to 88% of the chlorination reaction is performed in the main reactor. The one-stage boiling chlorination furnace is the secondary reactor, and 20% to 45% of the chlorination reaction is performed in the main reactor. carried out in the secondary reactor.

In some embodiments, the one-stage boiling chlorination furnace is configured to feed materials at the upper end and discharge materials at the lower end.

In some embodiments, the two-stage boiling chlorination furnace is configured to feed materials at the lower end and discharge materials at the upper end.

In some embodiments, chlorination conditions include gas flow, temperature, and gas velocity.

In some embodiments, the reaction temperature of the two-stage boiling chlorination furnace is 20-40°C higher than the reaction temperature of the one-stage boiling chlorination furnace.

In some embodiments, the gas velocity in the two-stage boiling chlorination furnace is 0.03 m/s to 0.05 m/s higher than the gas velocity in the one-stage boiling chlorination furnace.

In some embodiments, the gas supply pipes of the two-stage boiling chlorination furnace and the one-stage boiling chlorination furnace are equipped with a regulating valve and a flow meter, and the gas velocity in the boiling furnace is adjusted through the regulating valve.

In some embodiments, the first-stage boiling chlorination furnace and the second-stage boiling chlorination furnace are provided at the connection There is a fluidized discharge valve connection.

In some embodiments, the reactor diameters of the primary boiling chlorination furnace and the secondary boiling chlorination furnace are the same.

The present invention has at least the following beneficial technical effects:

The method of the present invention is based on an in-depth analysis of the carbonized slag material characteristics and the boiling chlorination reaction mechanism. By setting up two-stage boiling chlorination in series, high-concentration chlorine gas is introduced into the two-stage boiling chlorination furnace, and the two-stage boiling chlorination furnace is The remaining gas is introduced into the first-stage boiling chlorination furnace to achieve counter-current contact between chlorine gas and carbonized slag, increase the concentration difference between reactants, increase the reaction rate, and achieve contact reaction between high-concentration Cl ₂ and refractory carbonized slag (surface TiC has reacted) , low-concentration Cl ₂ reacts with TiC on the surface of the new carbonized slag, which not only improves the utilization rate of chlorine, greatly reduces alkali consumption, reduces the production cost of titanium tetrachloride, but also improves the chlorination rate and efficiency of the carbonized slag, thereby effectively increasing the titanium element in the carbonized slag. And the utilization rate of chlorination, improve the comprehensive chlorination effect, and enhance the market competitiveness of the blast furnace slag titanium extraction process.

Description of drawings

In order to explain the embodiments of the present invention or the technical solutions in the prior art more clearly, the drawings needed to be used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings in the following description are only These are some embodiments of the present invention. For those of ordinary skill in the art, other embodiments can be obtained based on these drawings without exerting creative efforts.

Figure 1 is a schematic diagram of an embodiment of the high-efficiency boiling chlorination method of carbonized slag provided by the present invention;

Figure 2 is a schematic diagram of an embodiment of a high-efficiency boiling chlorination device for carbonized slag provided by the present invention.

In the picture:
1-High-level silo, 2-Feeding screw and matching frequency conversion motor, 3-Carbonized slag feed fluidization U-shaped valve,
4-First-level boiling chlorination furnace, 5-First-level fluidized U-shaped slag discharge valve, 6-Second-level boiling chlorination furnace, 7-Tails slag discharge valve, 8-Gas mixing tank, 9-Tails slag Silo, 10-first-level cyclone dust collector, 11-secondary cyclone dust collector, 12-tailings silo, 13-first-level cyclone slag discharge valve, 14 tailings silo slag discharge valve, 15-secondary cyclone discharge Slag valve, 16-secondary cyclone dust removal and slag valve, 17-fluidized nitrogen flow meter, 18-fluidized nitrogen gas regulator Throttle valve, 19-fluidized chlorine gas flow meter, 20-fluidized chlorine gas regulating valve, 21-two-stage boiling chlorination furnace fluidized gas regulating valve, 22-supplementary nitrogen flow meter, 23-supplementary nitrogen regulating valve, 24-inlet Material U-shaped valve loose air regulating valve, 25-Feeding U-shaped valve conveying air regulating valve, 26-First-stage slag discharge U-shaped valve loose air regulating valve, 27-First-stage slag discharge U-shaped valve conveying air regulating valve.

Detailed ways

In order to make the purpose, technical solutions and advantages of the present invention more clear, the embodiments of the present invention will be further described in detail below with reference to specific embodiments and the accompanying drawings.

The terms "including" and "having" and any variations thereof in the description and claims of the present invention and the description of the above drawings are intended to cover non-exclusive inclusion; in the description and claims of the present invention or the description of the above drawings The terms "first", "second", etc. are used to distinguish different objects and are not used to describe a specific order. "Plural" means two or more, unless otherwise expressly and specifically limited.

Furthermore, reference herein to "an embodiment" means that a particular feature, structure or characteristic described in connection with the embodiment can be included in at least one embodiment of the present invention. The appearances of this phrase in various places in the specification are not necessarily all referring to the same embodiment, nor are separate or alternative embodiments mutually exclusive of other embodiments. Those skilled in the art understand, both explicitly and implicitly, that the embodiments described herein may be combined with other embodiments.

In view of the existing low-temperature selective chlorination efficiency of carbonized slag and high chlorine gas consumption, through in-depth analysis of the material characteristics of carbonized slag and the boiling chlorination reaction mechanism, it was found that the reaction between carbonized slag and chlorine is a typical gas-solid reaction, which can be divided into Two stages. The first stage is the contact reaction, which is controlled by the TiC reaction. The main reason is that under certain temperature conditions, the surface TiC in the carbonized slag comes into contact with Cl ₂ and reacts. The first stage reaction is fast and efficient. The second stage is the infiltration contact reaction, which is controlled by the penetration of Cl ₂ into the carbonized slag particles. The main process is: when the TiC reaction on the surface of the carbonized slag is completed, the TiC in the inner layer cannot be in direct and effective contact with Cl _2. Cl ₂ needs to penetrate into the interior of the carbonized slag particles and contact with TiC before the reaction can occur. Therefore, the reaction is affected by the Cl ₂ concentration, Cl _2. Penetration ability and control of particle cracks and channels on the surface of carbonized slag. In the same boiling chlorination reactor, when operated under the same conditions, the Cl ₂ concentration in the later stage of the reaction is low and the permeability is reduced; the surface TiC content is low and the reaction is slow, resulting in carbonized slag particles. The internal TiC reaction capacity is weakened, and the chlorine gas cannot be fully reacted, resulting in low overall chlorination rate of carbonized slag, low chlorine gas utilization rate, and high alkali consumption.

Therefore, in view of the problems existing in the prior art, the present invention proposes a high-efficiency boiling chlorination method of carbonized slag, combining the reaction characteristics of TiC and Cl ₂ , through two-stage boiling chlorination in series, chlorine gas and carbonized slag are counter-currently contacted to increase the reaction The concentration difference between the substances increases the reaction rate and achieves contact reaction between high-concentration Cl ₂ and refractory carbonized slag (surface TiC has reacted). Low-concentration Cl ₂ reacts with new carbonized slag surface TiC, which not only improves the chlorination rate and efficiency of carbonized slag. , while improving chlorine gas utilization and significantly reducing alkali consumption.

Figure 1 is a schematic diagram of an embodiment of the high-efficiency boiling chlorination method of carbonized slag provided by the present invention. The method includes the following steps:

S1 sets the chlorination conditions of the primary boiling chlorination furnace and the secondary boiling chlorination furnace based on the TiC content in the carbonized slag, and introduces high-concentration mixed gas into the secondary boiling chlorination furnace;

S2 adds the carbonized slag to the first-stage boiling chlorination furnace for preliminary chlorination reaction;

S3 discharges the carbonized slag after the preliminary chlorination reaction into the second-level boiling chlorination furnace for deep chlorination reaction. After the reaction, the tailings are discharged. The remaining gas in the second-level boiling chlorination furnace is dedusted by a cyclone and then passed into the first-level boiling chlorination furnace. furnace.

Further, the two-stage boiling chlorination furnace is the main reactor, 55% to 88% of the chlorination reaction is carried out in the main reactor, the one-stage boiling chlorination furnace is the secondary reactor, and 20% to 45% of the reaction is carried out in the side reaction performed within the device. The carbonized slag of the first-stage boiling chlorination furnace adopts the upper feeding and lower discharging method. It can not only maintain the continuous and stable flow of carbonized slag into and out of the boiling chlorination furnace, and controllable residence time of carbonized slag, but also increase the concentration gradient of reactants as much as possible. The lowest chlorine concentration and the highest TiC content carbonized slag contact reaction to improve chlorine gas utilization efficiency. The carbonized slag of the two-stage boiling chlorination furnace adopts the bottom feeding and top discharging method. The residence time of the carbonized slag in the two-stage boiling chlorination furnace is fully guaranteed to be stable. At the same time, the excessive chlorine gas and high concentration in the two-stage boiling chlorination furnace can ensure the full reaction of TiC in the carbonized slag.

In some embodiments, the first-stage boiling chlorination reactor and the second-stage boiling chlorination reactor are independent and designed with the same diameter. In other embodiments, different diameters can also be designed according to material characteristics, and the same gas distributor can also be designed. Can be designed into different gas distributors.

Further, chlorination conditions include gas flow, temperature, gas velocity, etc. : Determine the required amount of chlorine based on the reactor diameter, fluidization gas velocity and TiC content in the carbonized slag, calculate the amount of nitrogen to be added, complete the mixing of chlorine and nitrogen in the mixing tank and then enter the secondary boiling reactor to maintain The reaction within the reaction is stable, which can effectively prevent the local high chlorine concentration, violent reaction, and the failure of the reaction heat to be discharged in time, resulting in the end of the material. In order to enhance the rapid and efficient chlorination reaction of carbonized slag, the reaction temperature of the second-stage boiling chlorination furnace is 20-40°C higher than that of the first-stage boiling chlorination furnace; the gas velocity in the second-stage boiling chlorination furnace is higher than that of the first-stage boiling chlorination furnace. The speed is 0.03～0.05m/s.

Figure 2 shows a schematic diagram of an embodiment of a high-efficiency boiling chlorination device for carbonized slag provided by the present invention. The first-level boiling chlorination furnace 4 and the second-level boiling chlorination furnace 6 are connected in series. The carbonized slag is transmitted from the carbonized slag high-level bunker 1 through the feeding spiral and the matching frequency conversion motor 2, and passes through the first-level boiling furnace 4 and the second-level boiling chlorination furnace in sequence. 6. Among them, the carbonized slag feed valve, the discharge valve between the first-stage boiling chlorination furnace and the second-stage boiling chlorination furnace, and the second-stage boiling chlorination furnace slag discharge valve can choose a fluidized discharge valve, which can keep the material flowing smoothly. (The chlorinated slag after primary chlorination can effectively enter the secondary boiling chlorination furnace), and can effectively prevent gas from flowing back in the chlorination furnace. You can also choose stop valves, ball valves, etc. The first-stage boiling chlorination furnace 4 is equipped with a separate nitrogen gas supply pipe, equipped with a fluidized nitrogen regulating valve 18 and a fluidized chlorine gas flow meter 19 to regulate the gas velocity of the first-stage boiling chlorination furnace to ensure good flow in the reactor in the furnace. status.

The method for realizing high-efficiency boiling chlorination of carbonized slag of Panzhihua Iron and Steel Co., Ltd. using the present invention will be described in detail below with reference to specific examples.

This embodiment is a semi-industrial test. Both the first-level boiling chlorination reactor 4 and the second-level boiling chlorination reactor 6 are boiling chlorination reactors made of Φ200mm Income material. Canned liquid chlorine is used. A certain amount of liquid chlorine is vaporized and then sent The mixing tank and a certain amount of bottled nitrogen are decompressed and mixed as the fluidizing medium and reaction gas of the secondary boiling chlorination reactor. The raw material of carbonized slag is the blast furnace slag of the No. 1 blast furnace of Panzhihua Iron and Steel Group Corporation. It is the finished carbonized slag after high-temperature reduction, crushing and grinding in the electric furnace on the demonstration line. Its typical component distribution is shown in Table 1. Among them, the carbonized slag feed valve 3 and the first-stage boiling chlorination reactor slag discharge valve 5 are fluidized U-shaped valves, and the second-stage fluidized reactor rear slag discharge valve 7 is a ball valve.

The specific process includes the following steps:

After high-temperature carbonization reduction and crushing and grinding, the carbonized slag (finished carbonized slag produced by the high-temperature carbonization demonstration line) is added to the high-level silo 1 through the lifting device.

The typical particle size distribution of carbonized slag is analyzed by sampling and shown in Table 1. The minimum fluidization speed and minimum take-out speed of carbonized slag are calculated based on the average particle size of carbonized slag. It is determined that the gas velocity in the first-stage boiling chlorination reactor is controlled at 0.11~0.28m/s. , the preferred gas speed is 0.15m/s, the gas speed in the secondary boiling chlorination reaction is controlled at 0.15~0.33m/s, the preferred gas speed is 0.20m/s, the mixed gas flow rate introduced into the secondary boiling chlorination reactor is 16.96m3/h～37.2m3/h. The first-stage boiling chlorination reactor is not supplemented with nitrogen. The secondary boiling chlorination reaction temperature is controlled at 450-550°C, and the secondary boiling chlorination reaction temperature is controlled at 480-580°C.

According to the TiC content in the carbonized slag in Table 2, calculate the amount of chlorine gas, and add the amount of nitrogen according to the required gas problem.

According to the calculation results, set the chlorine gas amount, nitrogen gas amount, primary boiling chlorination furnace temperature, secondary boiling chlorination furnace temperature and other carbonized slag boiling chlorination conditions, open the fluidized chlorine gas regulating valve 20, the fluidized nitrogen gas regulating valve 18, The supplementary nitrogen regulating valve 23 adjusts the valve opening according to the readings of the fluidized chlorine flow meter 19, the fluidized nitrogen flow meter 17, and the supplementary nitrogen flow meter 22, controls the chlorine flow and nitrogen flow, and controls the mixed gas concentration. Start the boiling chlorination device, open the fluidizing gas regulating valve 21 of the secondary boiling chlorination furnace, and control the flow of fluidizing gas in the secondary boiling chlorination reactor.

The carbonized slag enters the high-level silo 1, opens the feeding screw and the matching variable frequency motor 2, and opens the loose gas regulating valve 24 and the conveying gas regulating valve 25 of the carbonized slag feed fluidizing U-shaped valve 3 to keep the carbonized slag feed unobstructed. Set the spiral frequency to 10Hz. After stabilizing for 5 minutes, gradually increase the frequency, increasing by 5Hz every 5 minutes, and finally stabilizing at 30Hz. The feeding amount is controlled at ~25kg/h, and the carbonized slag is added to the reactor of the first-stage boiling chlorination furnace 4. . In the early stage of feeding, close the loose gas regulating valve 26 and the conveying gas regulating valve 27 of the first-level fluidized slag discharge U-shaped valve 5 so that the materials in the first-level boiling chlorination furnace 4 cannot enter the second-level boiling chlorination furnace 6, forming a first-level boiling chlorination furnace. The carbonized slag layer in the boiling chlorination reactor.

60 minutes after the carbonized slag is fed, gradually open the loose gas regulating valve 26 and the conveying gas regulating valve 27 of the first-level fluidized slag discharge U-shaped valve 5, and discharge the chlorinated slag that has passed through the first-level boiling chlorination furnace 4 into the second-level The boiling chlorination furnace 6, the tailings slag discharge valve 7, the first-level cyclone slag discharge valve 13, and the tailings silo slag discharge valve 14 form a secondary boiling chlorination reactor material layer.

60 minutes after the secondary boiling chlorination reactor is fed, the secondary cyclone dust collector 10 is turned on, and the tailings slag discharge valve 7 and the primary cyclone slag discharge valve 13 are gradually opened, and the secondary boiling chlorination reactor begins to discharge outward. slag, regularly open the slag discharge valve 14 of the tailings silo to discharge the chlorinated tailings in the tailings silo from the system, but It is necessary to maintain a certain amount of chlorinated tailings in the tailings silo to form a material seal.

The gas after the secondary cyclone dust removal enters the primary boiling chlorination furnace 4 again, and the secondary chlorinated gas after the reaction is completed in the primary boiling chlorination furnace 4 enters the secondary cyclone dust collector 11, and the secondary cyclone slagging is started. Valve 15 allows the slag to enter the tailings silo 9, and the secondary cyclone dust removal and slag discharge valve 16 is opened regularly to collect the tailings, and the dust-removed gas enters the leaching process.

When the feeding is stable, the feeding amount reaches 20~28kg/h, and the first- and second-stage boiling chlorination reactors reach a certain filling rate. After the material layer is stabilized, the average residence time of carbonized slag in the first-stage boiling chlorination furnace is maintained at 40-90 min. , the average residence time of carbonized slag in the secondary boiling chlorination furnace is maintained at 60 to 120 minutes, and the system reaches balance. Multiple rounds of sampling were conducted to detect the particle size and chemical composition of the chlorinated tailings. The typical particle size distribution of carbonized residue and chlorinated tailings is shown in Table 1, the main components of carbonized residue and chlorinated tailings are shown in Table 2, and the main chemical components of chlorinated tailing gas are shown in Table 3.

Table 1 Typical particle size distribution of carbonized slag and chlorinated tailings/%

Table 2 Main chemical components of chlorinated tailings/%

Table 3 Main chemical components of chlorinated tail gas/(vt%)

It can be seen from Table 2 and Table 3 that the chlorination rate of carbonized slag can be increased to more than 88% using the technology of the present invention, which is significantly improved compared with the original chlorination rate during normal production (the average chlorination rate in 2021 is 82.5%); chlorinated tail gas The Cl ₂ content in the machine was reduced from 3.98% to 0.23%, and the Cl ₂ utilization rate was significantly improved.

To sum up, the present invention has the following advantages:

In order to solve the problems of low boiling chlorination rate of carbonized slag and low chlorine gas utilization rate, by setting up two-stage boiling chlorination in series, the carbonized slag and chlorine gas are counter-currently contacted with the chlorination process to increase the concentration difference between the reactants and increase the reaction rate. , improve the chlorination efficiency of carbonized slag before discharging it from the system, improve the chlorination rate of Ti in the blast furnace slag and the utilization rate of chlorine gas, achieve efficient recycling of Ti in the blast furnace, and improve the economy of the entire process. The method is simple and reliable; has good continuous stability and high efficiency; the equipment is simple to manufacture, has low investment, small floor space, good continuity, low energy consumption, stable operation, large processing capacity, and easy industrialization.

The above are exemplary embodiments disclosed by the present invention, but it should be noted that various changes and modifications can be made without departing from the scope of the disclosed embodiments of the present invention defined by the claims. The functions, steps and/or actions of the method claims in accordance with the disclosed embodiments described herein need not be performed in any particular order. In addition, although the elements disclosed in the embodiments of the present invention may be described or claimed in individual form, they may also be understood as plural unless expressly limited to the singular.

It will be understood that, as used herein, the singular form "a" and "an" are intended to include the plural form as well, unless the context clearly supports an exception. It will also be understood that as used herein, "and/or" is meant to include any and all possible combinations of one or more of the associated listed items.

The embodiment numbers disclosed in the above embodiments of the present invention are only for description and do not represent the advantages or disadvantages of the embodiments.

Those of ordinary skill in the art should understand that the above discussion of any embodiments is only illustrative, and is not intended to imply that the scope of the disclosure of the embodiments of the present invention (including the claims) is limited to these examples; under the thinking of the embodiments of the present invention , the above embodiments or technical features in different embodiments can also be combined, and there are many other changes in different aspects of the above embodiments of the present invention, which are not provided in details for the sake of simplicity. Therefore, any omissions, modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the embodiments of the present invention shall be included in the protection scope of the embodiments of the present invention.

Claims (10)

An efficient boiling chlorination method for carbonized slag, which is characterized by including: The chlorination conditions of the first-level boiling chlorination furnace and the second-level boiling chlorination furnace are set based on the TiC content in the carbonized slag, and a high-concentration mixed gas is passed into the second-level boiling chlorination furnace, wherein the first-level boiling chlorine The chlorination furnace and the two-stage boiling chlorination furnace are connected in series; Add carbonized slag into the first-stage boiling chlorination furnace to perform preliminary chlorination reaction; The carbonized slag after the preliminary chlorination reaction is discharged into the two-stage boiling chlorination furnace for deep chlorination reaction, and the tailings are discharged after the reaction. The remaining gas in the two-stage boiling chlorination furnace is passed through the cyclone dust removal The first-stage boiling chlorination furnace. The high-efficiency boiling chlorination method of carbonized slag according to claim 1, characterized in that the two-stage boiling chlorination furnace is the main reactor, and 55% to 88% of the chlorination reaction is performed in the main reactor, The first-stage boiling chlorination furnace is a secondary reactor, and 20% to 45% of the reaction is carried out in the secondary reactor. The high-efficiency boiling chlorination method of carbonized slag according to claim 1, characterized in that the first-stage boiling chlorination furnace is configured to feed materials at the upper end and discharge materials at the lower end. The high-efficiency boiling chlorination method of carbonized slag according to claim 3, characterized in that the two-stage boiling chlorination furnace is configured to feed materials at the lower end and discharge materials at the upper end. The high-efficiency boiling chlorination method of carbonized slag according to claim 1, wherein the chlorination conditions include gas flow, temperature and gas velocity. The high-efficiency boiling chlorination method of carbonized slag according to claim 5, characterized in that the reaction temperature of the two-stage boiling chlorination furnace is 20-40°C higher than the reaction temperature of the one-stage boiling chlorination furnace. The high-efficiency boiling chlorination method of carbonized slag according to claim 5, characterized in that the gas velocity in the two-stage boiling chlorination furnace is 0.03m/s to 0.05m higher than the gas velocity in the one-stage boiling chlorination furnace. /s. The high-efficiency boiling chlorination method of carbonized slag according to claim 7, characterized in that the gas supply pipes of the two-stage boiling chlorination furnace and the one-stage boiling chlorination furnace are equipped with a regulating valve and a flow meter. A regulating valve regulates the gas velocity within the boiling furnace. The high-efficiency boiling chlorination method of carbonized slag according to claim 1, characterized in that the first-stage boiling chlorination furnace and the second-stage boiling chlorination furnace are connected by a fluidized discharge valve at the connection point. The high-efficiency boiling chlorination method of carbonized slag according to claim 1, characterized in that the reactor diameters of the first-stage boiling chlorination furnace and the second-stage boiling chlorination furnace are the same.