RU2824640C1 - Method of processing antimony-containing materials - Google Patents

Abstract

FIELD: various technological processes.

SUBSTANCE: invention relates to pre-treatment of ores or scrap, particularly to processing of antimony-containing materials. Method involves mixing crushed antimony-containing materials with coal at ratio of 10 parts of crushed antimony-containing materials to 3 parts of coal to 10 parts of crushed antimony-containing materials to 4 parts of coal. Mixture is fired in furnace at temperature from 1,300 to 1,500 °C with simultaneous movement at speed of 0.3 to 1.5 m/min. At the same time inside the furnace the speed of gases movement is maintained from 1 to 5 m/s, and after burning of the mixture the obtained sublimates are trapped in the filter.

EFFECT: higher level of extraction of antimony in sublimates.

6 cl, 4 tbl

Description

The invention relates to the pre-treatment of ores or scrap using a roasting method, in particular to a method for processing antimony-containing materials [C22B 1/00, C22B 1/02, C22B 30/02, C22B 1/216].

A METHOD FOR PROCESSING METAL FROM FOIL ASH is known from the prior art [CN111286618A], which uses reducing smelting of pellet raw materials, the granules of the material are initially extracted by reducing smelting to obtain a raw tin alloy product, and then copper is removed from the raw tin alloy to improve the tin content in the raw tin alloy, and the raw tin after removing copper is fractionated and refined in a vacuum furnace to obtain a tin-copper alloy with a tin content of more than 97.5% and a by-product with a high Pb content, the granulated pellets are heated and sintered in a rotary kiln at a temperature of 500-600 ° C with the addition of auxiliary materials of coal powder, quartz sand and limestone, the added mass of pulverized coal is 8-10% of the added mass of the pellet raw materials.

The closest in technical essence is the METHOD OF PROCESSING MERCURY-ANTIMONY CONCENTRATES IN A FLUIDIZED BED FURNACE [SU157782A1], carried out according to the scheme of distillation roasting (for the purpose of selective extraction of mercury) in retort furnaces with subsequent precipitation smelting of the cinders obtained during roasting into rough antimony, characterized in that the initial concentrates are processed in a fluidized bed furnace at a temperature of about 500 °C with the return and additional roasting of the dust captured from the exhaust gases in a chamber installed in the cavity of the fluidized bed furnace and the gases purified from dust are sent for condensation to capture mercury, and the large and small cinders are combined and sent for the extraction of antimony from them.

The main technical disadvantage of the analogue and prototype is the insufficient level of extraction of antimony into sublimates during the processing of antimony-containing materials due to non-compliance with technological processes that allow increasing the level of extraction of antimony from antimony-containing materials during their processing.

The objective of the invention is to eliminate the shortcomings of the prototype.

The technical result of the invention is an increase in the level of extraction of antimony into sublimates during the processing of antimony-containing materials.

The specified technical result is achieved due to the fact that the method for processing antimony-containing materials is characterized by the fact that crushed antimony-containing materials are mixed with coal in a ratio of 10 parts of crushed antimony-containing materials to 3 parts of coal, up to 10 parts of crushed antimony-containing materials to 4 parts of coal, then the mixture is fired in a furnace at a temperature of 1300 degrees Celsius to 1500 degrees Celsius while simultaneously moving the mixture at a speed of 0.3 m/min to 1.5 m/min, while the speed of gas movement inside the furnace is maintained from 1 m/sec to 5 m/sec, after firing the resulting sublimates are captured in a filter.

In particular, antimony-containing materials are crushed to sizes from 15 mm to 25 mm.

In particular, the mixture is fired in a kiln.

In particular, the mixture is moved into the kiln by means of a device for raking the fired material.

In particular, a chain curtain is used as a device for raking the fired material inside the rotary kiln.

In particular, after firing, the resulting sublimations are captured in a bag filter.

Implementation of the invention.

A method for processing antimony-containing materials, where the materials are crushed to a size of 15–25 mm by crushing on commercially available crushing equipment, then mixed with coal in a ratio of 3–4 parts coal to 10 parts crushed antimony-containing materials (from 10:3 to 10:4). Mixing is carried out using dosing equipment. Next, the antimony materials are fired at a temperature of 1,300 to 1,500 degrees Celsius in a kiln with a device for raking the fired material in the firing zone at a movement speed of the antimony-containing material in the kiln of 0.3–1.5 m/min. The gas velocity inside the kiln is maintained within 1–5 m/sec. The resulting sublimates are captured in bag filters and sent to the production of commercial antimony. The cinders from the process are used to rehabilitate mine workings or to produce cement.

In one of the possible embodiments of the claimed invention, a rotary kiln is used as a firing furnace.

In one of the possible embodiments of the claimed invention, a chain curtain is used as a device for raking the fired material.

The declared technical result - an increase in the level of antimony extraction in sublimates during the processing of antimony-containing materials - is achieved due to the fact that antimony materials are mixed with coal in a ratio of 10:3 to 10:4. Such a ratio of materials ensures the creation of a sublimation mode for antimony contained in antimony materials under conditions of autogeneity of the roasting process. This, in turn, allows for an increase in the degree of antimony extraction in sublimates.

Then the materials are fired in a kiln with a device for raking the fired material at a temperature of 1300 to 1500 degrees. The stated temperature ensures complete transfer of antimony into sublimates, and the presence of a raking device allows the firing process to be carried out under conditions of melting of the fired materials. The device for raking the fired material means the use of any similar equipment known from the prior art, for example, a chain curtain used for these purposes in rotary kilns. A temperature below 1300 degrees Celsius will not allow a sufficient level of antimony extraction into sublimates, and more than 1450 will damage the quality of the final product and destroy the thermal insulation of the kiln, which will require stopping the kiln for repairs.

In this case, during the firing process, the speed of movement of materials in the furnace is maintained from 0.3 to 1.5 m/min. To comply with this stage, any firing furnace capable of using the process of mixing (movement) of materials, for example, a rotating furnace, can be used. The declared speed of movement of antimony-containing material inside the furnace ensures dust removal of the batch materials by no more than 2 - 3%, which, in turn, allows increasing the antimony content in the sublimates.

Also, the gas velocity inside the furnace is maintained within the range of 1 – 5 m/sec. The stated range allows achieving a reducing atmosphere inside the annealing zone, which also has a positive effect on the final level of antimony content in the sublimates.

After firing, the resulting sublimes are captured in bag filters. Without this stage, it will not be possible to capture freshly obtained antimony sublimes from the furnace.

Grinding materials to the specified sizes (size), in the embodiment of the method, also made it possible to achieve the stated technical result. Grinding to smaller sizes increases the probability of increased dust removal of the roasting residue and a decrease in the antimony content in the resulting antimony products. Grinding to larger sizes increases the probability of not obtaining a sufficient level of antimony extraction into sublimates.

As confirmation of the achievement of the technical result, the results of the conducted series of experiments are presented below:

1) Dependence of the firing temperature regime inside the firing furnace on the final extraction of antimony from antimony-containing material (Table 1).

2) The proportion of coal in the total mass of the calcined antimony-containing material and the influence of this proportion on the final amount of antimony obtained from this material (Table 2).

3) The ratio of the final amount of antimony in the absence and presence of a raking device inside the roasting furnace, the effect of the speed of movement of antimony-containing materials inside the roasting furnace on the final amount of antimony extracted from them, the effect of the speed of movement of gases inside the roasting furnace on the final amount extracted from antimony-containing materials, the effect of the presence of bag filters on the possibility of extracting the obtained antimony from the roasting furnace, subject to mixing before roasting the antimony-containing material with coal in a ratio of 100:30 and roasting the materials in the roasting furnace at a temperature of 1300 degrees Celsius (Table 3).

4) Carrying out the processing of antimony-containing material in compliance with all technological processes declared in the method (Table 4).

Table 1

Firing temperature (degrees Celsius) Extraction of antimony into sublimates (%) at a gas velocity of more than 5 m/sec 800 42.9 900 44.1 1000 63.2 1100 68.7 1200 74.5 1300 75.8

Table 2

The proportion of the ratio of antimony-containing material to carbon Extraction of antimony into sublimates (%) The speed of gas movement is more than 5 m/sec at a temperature of 1300 °C The speed of gas movement is 2-5 m/sec at a temperature of 1300 °C 100:10 52.3 68.2 100:20 64.5 85.4 100:30 74.2 94.1 100:40 75.8 94.5 100:50 84.3 89.1 100:60 82.7 87.2

Table 3

Production stage Extraction of antimony into sublimates (%) Availability of a raking device 94.5 Lack of raking device 68.3 The speed of movement of antimony-containing materials is less than 0.3 m/min 87.2 The speed of movement of antimony-containing materials is more than 1.5 m/min 61.3 The speed of gas movement is more than 5 m/sec 75.8 The speed of gas movement is less than 1 m/sec 82.8 The resulting sublimates are captured in bag filters. 94.5 The resulting sublimates are not captured in bag filters. 0

Table 4

Description of the firing process Extraction of antimony into sublimates (%) The crushed antimony-containing materials are mixed with coal in a ratio of 10 parts crushed antimony-containing materials to 3 parts coal, up to 10 parts crushed antimony-containing materials to 4 parts coal, then the mixture is fired in a furnace at a temperature of 1300 degrees Celsius to 1500 degrees Celsius, while simultaneously moving the mixture in the furnace at a speed of 0.3 m/min to 1.5 m/min, while the gas velocity inside the furnace is maintained at 1 m/sec to 5 m/sec, after firing the mixture, the resulting sublimates are captured in a filter 94.1 – 94.5

Based on the results of a series of experiments, the following conclusions can be drawn:

1) A ratio of coal to antimony-containing material of less than 100:30 leads to a decrease in the level of antimony extraction into sublimates; more than 100:40 does not increase the extraction of antimony into sublimates and, as a result, is an impractical process.

2) A firing temperature of less than 1300 degrees Celsius does not allow for a sufficient level of antimony extraction into sublimates, while more than 1500 will damage the furnace insulation and burn the antimony, preventing an increase in its content in sublimates.

3) The presence of a device for raking the fired material directly affects the increase in the level of antimony extraction in sublimates, while the absence of this device leads to the formation of accretions and a decrease in the level of antimony in sublimates.

4) The speed of movement of antimony-containing material inside the furnace of less than 0.3 m/min reduces the productivity of the process, more than 1.5 m/min increases the dust removal of the batch materials by more than 2–3%, which, in turn, reduces the antimony content in the sublimates.

5) The speed of gas movement inside the furnace is less than 1 m/sec and more than 5 m/sec, which does not allow achieving a reducing atmosphere inside the firing zone, which negatively affects the final level of antimony extraction into sublimates.

6) The absence of a stage for capturing antimony in bag filters does not allow capturing antimony sublimates released from the furnace, which will lead to the lowest level of antimony in the resulting sublimates – zero, as well as to environmental pollution.

Thus, only in combination the above-mentioned features make it possible to achieve the stated technical result - an increase in the level of antimony extraction into sublimates during the processing of antimony-containing materials.

Claims (6)

1. A method for processing antimony-containing materials, characterized in that crushed antimony-containing materials are mixed with coal in a ratio of 10 parts crushed antimony-containing materials to 3 parts coal to 10 parts crushed antimony-containing materials to 4 parts coal, then the mixture is fired in a furnace at a temperature of 1300°C to 1500°C while simultaneously moving the mixture in the furnace at a speed of 0.3 m/min to 1.5 m/min, while the gas velocity inside the furnace is maintained at 1 m/s to 5 m/s, after firing the mixture the resulting sublimates are captured in a filter. 2. The method according to item 1, characterized in that the antimony-containing materials are crushed to sizes from 15 mm to 25 mm. 3. The method according to item 1, characterized in that the mixture is fired in a kiln. 4. The method according to item 1, characterized in that the mixture is moved in the furnace by means of a device for raking the fired material. 5. The method according to paragraph 4, characterized in that a chain curtain is used as a device for raking the fired material inside the furnace. 6. The method according to item 1, characterized in that after firing, the resulting sublimates are captured in a bag filter.