Deep tellurium removal method for pyrogenic process antimony smelting

Abstract

A deep tellurium removal method for pyrogenic process antimony smelting comprises the following steps: (1) determining the weight of a tellurium removal reagent according to the tellurium content in crude antimony, and heating to melt the antimony; (2) heating to a certain temperature to melt antimony, adding a tellurium removal reagent, and stirring by adopting compressed air; and (3) slagging off and discharging after the reaction is completed, and separating antimony from slag. The method has the advantages that 1, the tellurium removal effect is good, and tellurium impurities in crude antimony are effectively reduced to be within a product demand range value; 2, the fixed number of workers is small, and the treatment cost is low; 3, the treatment time is short, and the treatment efficiency is high; and 4, the treatment capacity is high, the operation control is easy, the management and maintenance are convenient, and the investment is low.

Description

Technical Field

[0001] The invention relates to the technical field of impurity removal in pyrometallurgical antimony smelting, and in particular to a method for deep tellurium removal in pyrometallurgical antimony smelting. Background Art

[0002] Antimony is an important metal widely used in all aspects of the national economy. At present, due to the increasing amount of tellurium in the raw materials for antimony smelting, the tellurium content in the production process of antimony ingots is generally between several hundred ppm and several thousand ppm. The presence of tellurium will seriously affect the quality and use effect of antimony ingots, not only reducing the mechanical strength, hardness and toughness of antimony ingots, but also affecting its electrical properties such as conductivity and resistivity. When the tellurium content exceeds a certain amount, it will also have a great impact on the quality of products such as antimony white, which seriously restricts the application of antimony products in industry. At present, the existing process equipment in industrial production is increasingly difficult to complete the original process indicators and production tasks, especially the removal of tellurium. There is currently no good method, which makes it increasingly difficult for the quality of production products to meet customer needs. The product needs to be diluted and antimony without tellurium is added to meet the requirements, resulting in higher and higher costs.

[0003] There are generally two commonly used methods for removing tellurium in industry. One is the pyrochlorination roasting method, which is to add antimony ingots to a mixture of ferric chloride and sodium chloride, and then roast them at high temperature to oxidize the tellurium element into tellurium chloride gas, thereby achieving the purpose of removing tellurium. Although this method is simple to operate, it is only applicable to antimony ingots with low tellurium content, and there are serious problems of chlorine pollution and high energy consumption. Another commonly used method is the wet leaching method, which is to subject the tellurium-containing crude antimony to multiple oxidation leaching and evaporation processes to oxidize and evaporate the tellurium element, thereby achieving the purpose of removing impurities. This method is used to treat crude antimony with a high tellurium content, but the wet process has problems such as lengthy and complex procedures, high costs, and low leaching efficiency.

[0004] CN111041238A discloses a tellurium removal agent for antimony smelting production and its application. The tellurium removal agent for antimony refining is prepared by using three substances, namely, metal element sodium or sodium-containing compounds, metal element potassium or potassium-containing compounds, and metal element calcium or calcium-containing compounds, alone or in a certain proportion. The tellurium removal agent is added to the furnace during the reverberatory furnace for antimony smelting. After the reaction is completed, the tellurium removal slag produced will float on the surface of the antimony liquid, and the tellurium removal slag will be removed from the furnace through the operating door. The disadvantage of this method is that it takes a long time and needs to reach 950-1000℃, which will lead to an increase in the output of secondary antimony oxide and increase the production cost. The tellurium removal agent in its embodiment requires a mixed ratio of three reagents, the reagent dosage is large and it is easy to introduce new impurities. Summary of the invention

[0005] The technical problem to be solved by the present invention is to overcome the deficiencies of the prior art and provide a method for deep tellurium removal in pyrometallurgical antimony smelting with a simpler process and lower cost.

[0006] The technical solution adopted by the present invention to solve the technical problem is a method for deep tellurium removal from pyrometallurgical antimony smelting, comprising the following steps:

[0007] (1) Determine the weight of the tellurium removal reagent according to the tellurium content in the crude antimony, and heat to melt the antimony;

[0008] (2) After heating to a certain temperature (preferably 800-900°C) to melt the antimony, add a tellurium removal agent and stir with compressed air;

[0009] Under certain temperature conditions, especially 800-900℃, compressed air can be used for melt stirring and can also provide oxygen to oxidize tellurium in the metal melt, accelerate the formation of tellurium oxide, and further accelerate the reaction with the tellurium removal agent to quickly generate slag. Other inert gases cannot do this, and mechanical stirring is even more impossible.

[0010] (3) After the reaction is completed, the slag is removed from the furnace and the antimony and slag are separated.

[0011] Preferably, in step (1), the tellurium content in the crude antimony is 50 ppm-350 ppm.

[0012] Preferably, in step (1), the weight of tellurium removal reagent: weight of tellurium contained in crude antimony = 150-300:1.

[0013] Preferably, in step (1), the specific operation of heating and melting antimony is: heating the crude antimony to 800-900° C. to melt the crude antimony into antimony water.

[0014] Preferably, in step (2), the tellurium removal reagent is a mixture of reagent A and reagent B, wherein A is sodium hydroxide and B is potassium hydroxide. At different refining temperatures, adding reagent A or reagent B alone is effective for tellurium removal, but after adding the mixed reagents, the tellurium removal effect is better within a certain ratio range, resulting in a synergistic effect.

[0015] Preferably, in step (2), in the tellurium removal reagent, the weight percentage of reagent A is 60-90%, and the weight percentage of reagent B is 10-40%. The present invention can reduce the tellurium content in crude antimony to below 10 ppm, and even to 3 ppm at the lowest.

[0016] Preferably, in step (2), the tellurium removal temperature is 800-900°C.

[0017] Preferably, in step (2), the tellurium removal reaction time is 40-80 minutes.

[0018] Preferably, in step (3), separation of antimony and slag means that after the synergistic action of tellurium removal reagents A and B, refined antimony and tellurium removal slag are separated by layers due to the difference in density. Refined antimony can further meet the quality requirements of deep-processing products.

[0019] The present invention aims to provide a simple and efficient method for removing tellurium from antimony by pyrometallurgical smelting. After the crude antimony is treated by this method, the tellurium content in the antimony is reduced to below 10ppm, meeting the quality requirements of deep-processed products such as refined antimony or antimony white. This method is very suitable for deep removal of tellurium elements in the antimony smelting process.

[0020] The purpose of the present invention is to remove tellurium from tellurium-containing crude antimony, that is, to select and study key tellurium removal reagents and appropriate process conditions during the reverberatory furnace refining process, so as to achieve the goal of removing tellurium in antimony to below 10 ppm, reduce the introduction of new impurities, improve economic benefits, meet the quality requirements of deep-processing products such as refined antimony or antimony white, and expand the application field of antimony products in industry.

[0021] Advantages of the present invention:

[0022] 1. The present invention has a good tellurium removal effect and effectively reduces the tellurium impurities in crude antimony to within the product demand range;

[0023] 2. The present invention requires less labor and has low processing cost;

[0024] 3. The present invention has short processing time and high processing efficiency;

[0025] 4. The present invention has large processing capacity, is easy to operate and control, is convenient to manage and maintain, and requires little investment. DETAILED DESCRIPTION

[0026] The present invention is further described in detail below in conjunction with specific embodiments.

[0027] Example 1

[0028] The method for deep tellurium removal from pyrometallurgical antimony smelting of this embodiment uses crude antimony purchased by Xikuangshan Shanxing Antimony Industry Co., Ltd. as raw material, which contains 99.76% antimony, 0.049% arsenic and 0.035% tellurium. According to the steps of the present invention, 503.5g of crude antimony containing tellurium is weighed, placed in a muffle furnace, heated to 850°C, and 42.5g of tellurium removal reagent is added, the tellurium removal reagent is a mixture of reagent A and reagent B, A is sodium hydroxide, and B is potassium hydroxide; in the tellurium removal reagent, the weight percentage of reagent A is 60%, and the weight percentage of reagent B is 40%; under the condition of 850°C, the mixed tellurium removal reagent is added to the molten antimony water, and compressed air is used for stirring, and the reaction with the antimony water is 60 minutes. After the reaction is completed, it is naturally clarified and layered to achieve the purpose of separation of antimony and tellurium. After the reaction, the weight of refined antimony was 456.8g, and the weight of slag was 85.4g. Chemical analysis of refined antimony and slag showed that the refined antimony contained 2ppm arsenic and 6ppm tellurium; the slag contained 52.99% antimony, 0.36% arsenic, and 0.11% tellurium. The test results showed that the direct recovery rate of antimony was 90.7% and the tellurium removal rate was 98.4%.

[0029] Example 2

[0030] A method for deep tellurium removal in pyrometallurgical antimony smelting, using crude antimony purchased by Xikuangshan Shanxing Antimony Industry Co., Ltd. as raw material, wherein the raw antimony contains 99.76% antimony, 0.049% arsenic and 0.035% tellurium. According to the steps of the present invention, 502g of crude antimony containing tellurium is weighed, placed in a muffle furnace, and heated to 900°C, and a tellurium removal reagent weighs 42.5g, the tellurium removal reagent is a mixture of reagent A and reagent B, A is sodium hydroxide, and B is potassium hydroxide; in the tellurium removal reagent, the weight percentage of reagent A is 90%, and the weight percentage of reagent B is 10%; under the condition of 900°C, the mixed tellurium removal reagent is added to the melted antimony water, and the mixture is stirred with compressed air to react with the antimony water for 40 minutes, and after the reaction is completed, the mixture is naturally clarified and layered to achieve the purpose of separation of antimony and tellurium. After the reaction, the weight of refined antimony was 461.2g, and the weight of slag was 81.1g. Chemical analysis of refined antimony and slag showed that the refined antimony contained 19ppm arsenic and 8ppm tellurium; the slag contained 41.32% antimony, 0.38% arsenic, and 0.088% tellurium. The test results showed that the direct recovery rate of antimony was 91.9% and the tellurium removal rate was 97.9%.

[0031] Example 3

[0032] A method for deep tellurium removal in pyrometallurgical antimony smelting, using crude antimony purchased by Xikuangshan Shanxing Antimony Industry Co., Ltd. as raw material, wherein the raw antimony contains 99.76% antimony, 0.049% arsenic and 0.035% tellurium. According to the steps of the present invention, 503g of crude antimony containing tellurium is weighed, placed in a muffle furnace, and heated to 800°C, a tellurium removal reagent weighs 45g, the tellurium removal reagent is a mixture of reagent A and reagent B, A is sodium hydroxide, and B is potassium hydroxide; in the tellurium removal reagent, the weight percentage of reagent A is 70%, and the weight percentage of reagent B is 30%; under the condition of 800°C, the mixed tellurium removal reagent is added to the melted antimony water, and the mixture is stirred with compressed air to react with the antimony water for 80 minutes, and after the reaction is completed, the mixture is naturally clarified and layered to achieve the purpose of separation of antimony and tellurium. After the reaction, the weight of refined antimony was 463g, and the weight of slag was 87.5g. Chemical analysis of refined antimony and slag showed that the refined antimony contained 6ppm arsenic and 3ppm tellurium; the slag contained 46.95% antimony, 0.29% arsenic, and 0.12% tellurium. The test results showed that the direct recovery rate of antimony was 92.0% and the tellurium removal rate was 99.2%.

[0033] Example 4

[0034] A method for deep tellurium removal from pyrometallurgical antimony smelting, using crude antimony purchased by Xikuangshan Shanxing Antimony Industry Co., Ltd. as raw material, wherein the raw antimony contains 99.76% antimony, 0.049% arsenic and 0.035% tellurium. According to the steps of the present invention, 500g of crude antimony containing tellurium is weighed, placed in a muffle furnace, and heated to 830°C, a tellurium removal reagent weighs 40g, the tellurium removal reagent is a mixture of reagent A and reagent B, A is sodium hydroxide, and B is potassium hydroxide; in the tellurium removal reagent, the weight percentage of reagent A is 80%, and the weight percentage of reagent B is 20%; under the condition of 830°C, the mixed tellurium removal reagent is added to the melted antimony water, and the mixture is stirred with compressed air to react with the antimony water for 60 minutes, and after the reaction is completed, the mixture is naturally clarified and layered to achieve the purpose of separation of antimony and tellurium. After the reaction, the weight of refined antimony was 464g, and the weight of slag was 79.5g. Chemical analysis of refined antimony and slag showed that the refined antimony contained 9ppm arsenic and 4ppm tellurium; the slag contained 49.14% antimony, 0.26% arsenic, and 0.16% tellurium. The test results showed that the direct recovery rate of antimony was 92.8% and the tellurium removal rate was 98.9%.

[0035] Example 5

[0036] A method for deep tellurium removal in pyrometallurgical antimony smelting, using crude antimony purchased by Xikuangshan Shanxing Antimony Industry Co., Ltd. as raw material, wherein the raw antimony contains 99.79% antimony, 0.047% arsenic and 0.005% tellurium. According to the steps of the present invention, 500.3g of crude antimony containing tellurium is weighed, placed in a muffle furnace, and heated to 800°C, and the tellurium removal reagent weighs 7.5g, the tellurium removal reagent is a mixture of reagent A and reagent B, A is sodium hydroxide, and B is potassium hydroxide; in the tellurium removal reagent, the weight percentage of reagent A is 80%, and the weight percentage of reagent B is 20%; under the condition of 800°C, the mixed tellurium removal reagent is added to the melted antimony water, and the mixture is stirred with compressed air to react with the antimony water for 60 minutes, and after the reaction is completed, the mixture is naturally clarified and layered to achieve the purpose of separation of antimony and tellurium. After the reaction, the weight of refined antimony was 462.3g, and the weight of slag was 78.4g. Chemical analysis of refined antimony and slag showed that the refined antimony contained 11ppm arsenic and 9ppm tellurium; the slag contained 41.78% antimony, 0.28% arsenic, and 0.03% tellurium. The test results showed that the direct recovery rate of antimony was 92.4% and the tellurium removal rate was 83.4%.

[0037] In this embodiment, because the tellurium content in the raw material is low, the reaction rate of tellurium and the tellurium removal agent is limited by the reaction kinetics under low tellurium content conditions. Due to the low tellurium content, the contact opportunities between the reactants are reduced, resulting in an incomplete reaction, which affects the tellurium removal rate. When the tellurium content in the raw material is low, it becomes more difficult to separate tellurium from other components, resulting in a decrease in the tellurium removal rate.

[0038] Example 6

[0039] A method for deep tellurium removal in pyrometallurgical antimony smelting, using crude antimony purchased by Xikuangshan Shanxing Antimony Industry Co., Ltd. as raw material, wherein the raw antimony contains 99.79% antimony, 0.047% arsenic and 0.005% tellurium. According to the steps of the present invention, 500.8g of crude antimony containing tellurium is weighed, placed in a muffle furnace, and heated to 900°C, and the tellurium removal reagent weighs 7.5g, the tellurium removal reagent is a mixture of reagent A and reagent B, A is sodium hydroxide, and B is potassium hydroxide; in the tellurium removal reagent, the weight percentage of reagent A is 80%, and the weight percentage of reagent B is 20%; under the condition of 900°C, the mixed tellurium removal reagent is added to the melted antimony water, and the mixture is stirred with compressed air to react with the antimony water for 60 minutes, and after the reaction is completed, the mixture is naturally clarified and layered to achieve the purpose of separation of antimony and tellurium. After the reaction, the weight of refined antimony was 461.6g, and the weight of slag was 82g. Chemical analysis of refined antimony and slag showed that the refined antimony contained 9ppm arsenic and 10ppm tellurium; the slag contained 42.25% antimony, 0.26% arsenic, and 0.024% tellurium. The test results showed that the direct recovery rate of antimony was 92.2% and the tellurium removal rate was 81.6%.

[0040] In this embodiment, because the tellurium content in the raw material is low, the reaction rate of tellurium and the tellurium removal agent is limited by the reaction kinetics under low tellurium content conditions. Due to the low tellurium content, the contact opportunities between the reactants are reduced, resulting in an incomplete reaction, which affects the tellurium removal rate. When the tellurium content in the raw material is low, it becomes more difficult to separate tellurium from other components, resulting in a decrease in the tellurium removal rate.

[0041] Example 7

[0042] A method for deep tellurium removal from pyrometallurgical antimony smelting, using crude antimony purchased by Xikuangshan Shanxing Antimony Industry Co., Ltd. as raw material, wherein the raw antimony contains 99.71% antimony, 0.052% arsenic and 0.02% tellurium. According to the steps of the present invention, 501.3g of crude antimony containing tellurium is weighed, placed in a muffle furnace, and heated to 850°C, a tellurium removal reagent weighs 28g, the tellurium removal reagent is a mixture of reagent A and reagent B, A is sodium hydroxide, and B is potassium hydroxide; in the tellurium removal reagent, the weight percentage of reagent A is 80%, and the weight percentage of reagent B is 20%; under the condition of 850°C, the mixed tellurium removal reagent is added to the melted antimony water, and the mixture is stirred with compressed air to react with the antimony water for 60 minutes, and after the reaction is completed, the mixture is naturally clarified and layered to achieve the purpose of separation of antimony and tellurium. After the reaction, the weight of refined antimony was 463.8g, and the weight of slag was 83.6g. Chemical analysis of refined antimony and slag showed that the refined antimony contained 26ppm arsenic and 8ppm tellurium; the slag contained 47.31% antimony, 0.28% arsenic, and 0.11% tellurium. The test results showed that the direct recovery rate of antimony was 92.5% and the tellurium removal rate was 96.3%.

[0043] Comparative Example 1

[0044] A method for deep tellurium removal in pyrometallurgical antimony smelting, using crude antimony purchased by Xikuangshan Shanxing Antimony Industry Co., Ltd. as raw material, wherein the raw antimony contains 99.76% antimony, 0.049% arsenic and 0.035% tellurium. According to the steps of the present invention, 502.4g of crude antimony containing tellurium is weighed, placed in a muffle furnace, heated to 850°C, and the tellurium removal reagent weighs 33.5g, and the tellurium removal reagent is sodium hydroxide; under the condition of 850°C, the tellurium removal reagent is added to the molten antimony water, stirred with compressed air, and reacted with the antimony water for 60 minutes, and after the reaction is completed, it is naturally clarified and layered to achieve the purpose of separation of antimony and tellurium. After the reaction, the refined antimony weighs 464g and the slag weighs 65.4g. Chemical detection and analysis are performed on the refined antimony and the slag respectively, and the refined antimony contains 29ppm arsenic and 35ppm tellurium; the slag contains 44.34% antimony, 0.3% arsenic and 0.22% tellurium. The test results show that the direct recovery rate of antimony is 92.4% and the detellurization rate is 90.9%.

[0045] This comparative example shows that the tellurium removal effect of using only sodium hydroxide as the tellurium removal reagent is not as good as that of using a mixture of reagent A and reagent B as the tellurium removal reagent.

[0046] Comparative Example 2

[0047] A method for deep tellurium removal from pyrometallurgical antimony smelting, using crude antimony purchased by Xikuangshan Shanxing Antimony Industry Co., Ltd. as raw material, wherein the raw antimony contains 99.76% antimony, 0.049% arsenic, and 0.035% tellurium. According to the steps of the present invention, 503.9g of crude antimony containing tellurium is weighed, placed in a muffle furnace, and heated to 850°C, and the tellurium removal reagent weighs 33.5g, and the tellurium removal reagent is potassium hydroxide; under the condition of 850°C, the tellurium removal reagent is added to the molten antimony water, stirred with compressed air, and reacted with the antimony water for 60 minutes, and after the reaction is completed, it is naturally clarified and layered to achieve the purpose of separation of antimony and tellurium. After the reaction, the refined antimony weighs 441.5g and the slag weighs 103.5g. Chemical detection and analysis are performed on the refined antimony and the slag respectively, and the refined antimony contains 2ppm arsenic and 58ppm tellurium; the slag contains 40.36% antimony, 0.4% arsenic, and 0.14% tellurium. The test results show that the direct recovery rate of antimony is 87.6% and the detellurization rate is 85.5%.

[0048] This comparative example shows that the tellurium removal effect of using only potassium hydroxide as the tellurium removal reagent is not as good as that of using a mixture of reagent A and reagent B as the tellurium removal reagent.

[0049] Comparative Example 3

[0050] A method for deep tellurium removal in pyrometallurgical antimony smelting, using crude antimony purchased by Xikuangshan Shanxing Antimony Industry Co., Ltd. as raw material, wherein the raw antimony contains 99.76% antimony, 0.049% arsenic and 0.035% tellurium. According to the steps of the present invention, 504.1g of crude antimony containing tellurium is weighed, placed in a muffle furnace, and heated to 750°C, and the tellurium removal reagent weighs 39.8g, the tellurium removal reagent is a mixture of reagent A and reagent B, A is sodium hydroxide, and B is potassium hydroxide; in the tellurium removal reagent, the weight percentage of reagent A is 80%, and the weight percentage of reagent B is 20%; under the condition of 750°C, the mixed tellurium removal reagent is added to the melted antimony water, and the mixture is stirred with compressed air to react with the antimony water for 60 minutes, and after the reaction is completed, the mixture is naturally clarified and layered to achieve the purpose of separation of antimony and tellurium. After the reaction, the weight of refined antimony was 452.5g, and the weight of slag was 79.5g. Chemical analysis of refined antimony and slag showed that the refined antimony contained 16ppm arsenic and 37ppm tellurium; the slag contained 51.34% antimony, 0.3% arsenic, and 0.2% tellurium. The test results showed that the direct recovery rate of antimony was 89.7% and the tellurium removal rate was 90.5%.

[0051] This comparative example shows that if the temperature of the tellurium removal reaction is too low, the effect of tellurium removal will be affected.

[0052] Comparative Example 4

[0053] A method for deep tellurium removal in pyrometallurgical antimony smelting, using crude antimony purchased by Xikuangshan Shanxing Antimony Industry Co., Ltd. as raw material, wherein the raw antimony contains 99.76% antimony, 0.049% arsenic and 0.035% tellurium. According to the steps of the present invention, 503.6g of crude antimony containing tellurium is weighed, placed in a muffle furnace, and heated to 950°C, and a tellurium removal reagent weighs 39.8g, the tellurium removal reagent is a mixture of reagent A and reagent B, A is sodium hydroxide, and B is potassium hydroxide; in the tellurium removal reagent, the weight percentage of reagent A is 80%, and the weight percentage of reagent B is 20%; under the condition of 900°C, the mixed tellurium removal reagent is added to the melted antimony water, and the mixture is stirred with compressed air to react with the antimony water for 60 minutes, and after the reaction is completed, the mixture is naturally clarified and layered to achieve the purpose of separation of antimony and tellurium. After the reaction, the weight of refined antimony was 457.8g, and the weight of slag was 81.5g. Chemical analysis of refined antimony and slag showed that the refined antimony contained 50ppm arsenic and 51ppm tellurium; the slag contained 56.16% antimony, 0.18% arsenic, and 0.19% tellurium. The test results showed that the direct recovery rate of antimony was 90.9% and the tellurium removal rate was 86.8%.

[0054] This comparative example shows that if the temperature of the tellurium removal reaction is too high, the effect of tellurium removal will be affected.

[0055] Comparative Example 5

[0056] A method for deep tellurium removal in pyrometallurgical antimony smelting, using crude antimony purchased by Xikuangshan Shanxing Antimony Industry Co., Ltd. as raw material, wherein the raw antimony contains 99.76% antimony, 0.049% arsenic and 0.035% tellurium. According to the steps of the present invention, 500.7g of crude antimony containing tellurium is weighed, placed in a muffle furnace, and heated to 850°C, and the tellurium removal reagent weighs 32.5g, the tellurium removal reagent is a mixture of reagent A and reagent B, A is sodium hydroxide, and B is potassium hydroxide; in the tellurium removal reagent, the weight percentage of reagent A is 80%, and the weight percentage of reagent B is 20%; under the condition of 850°C, the mixed tellurium removal reagent is added to the melted antimony water, and the mixture is stirred with compressed air to react with the antimony water for 30 minutes, and after the reaction is completed, the mixture is naturally clarified and layered to achieve the purpose of separation of antimony and tellurium. After the reaction, the weight of refined antimony was 452.8g, and the weight of slag was 99.5g. Chemical analysis of refined antimony and slag showed that the refined antimony contained 21ppm arsenic and 40ppm tellurium; the slag contained 50.24% antimony, 0.26% arsenic, and 0.16% tellurium. The test results showed that the direct recovery rate of antimony was 90.4% and the tellurium removal rate was 89.7%.

[0057] This comparative example shows that if the tellurium removal reaction time is too short, the tellurium removal effect will be affected.

[0058] Comparative Example 6

[0059] A method for deep tellurium removal in pyrometallurgical antimony smelting, using crude antimony purchased by Xikuangshan Shanxing Antimony Industry Co., Ltd. as raw material, wherein the raw antimony contains 99.76% antimony, 0.049% arsenic and 0.035% tellurium. According to the steps of the present invention, 503.6g of crude antimony containing tellurium is weighed, placed in a muffle furnace, and heated to 830°C, and a tellurium removal reagent weighs 33.5g, the tellurium removal reagent is a mixture of reagent A and reagent B, A is sodium hydroxide, and B is potassium hydroxide; in the tellurium removal reagent, the weight percentage of reagent A is 80%, and the weight percentage of reagent B is 20%; under the condition of 830°C, the mixed tellurium removal reagent is added to the melted antimony water, and the mixture is stirred with compressed air to react with the antimony water for 90 minutes, and after the reaction is completed, the mixture is naturally clarified and layered to achieve the purpose of separation of antimony and tellurium. After the reaction, the weight of refined antimony was 461.2g, and the weight of slag was 81.1g. Chemical analysis of refined antimony and slag showed that the refined antimony contained 19ppm arsenic and 35ppm tellurium; the slag contained 41.32% antimony, 0.38% arsenic, and 0.19% tellurium. The test results showed that the direct recovery rate of antimony was 91.6% and the tellurium removal rate was 90.8%.

[0060] This comparative example shows that if the tellurium removal reaction time is too long, the tellurium removal effect will be affected. This is because during the long reaction process, some side reactions that are not conducive to tellurium removal may occur, and these side reactions may consume part of the tellurium removal agent or generate products that are not conducive to tellurium separation, thereby reducing the tellurium removal effect.

[0061] Comparative Example 7

[0062] A method for deep tellurium removal in pyrometallurgical antimony smelting, using crude antimony purchased by Xikuangshan Shanxing Antimony Industry Co., Ltd. as raw material, wherein the raw antimony contains 99.76% antimony, 0.049% arsenic and 0.035% tellurium. According to the steps of the present invention, 500.6g of crude antimony containing tellurium is weighed, placed in a muffle furnace, heated to 850°C, and 42.5g of a tellurium removal reagent is added, wherein the tellurium removal reagent is a mixture of reagent A, reagent B and reagent C, wherein A is sodium hydroxide, B is potassium hydroxide and C is calcium hydroxide; in the tellurium removal reagent, the weight percentage of reagent A is 60%, the weight percentage of reagent B is 20% and the weight percentage of reagent C is 20%; under the condition of 850°C, the mixed tellurium removal reagent is added to the melted antimony water, stirred by compressed air, reacted with the antimony water for 60 minutes, and after the reaction is completed, the mixture is naturally clarified and layered to achieve the purpose of separation of antimony and tellurium. After the reaction, the weight of refined antimony was 453.3g, and the weight of slag was 67.3g. Chemical analysis of refined antimony and slag showed that the refined antimony contained 58ppm arsenic and 56ppm tellurium; the slag contained 52.31% antimony, 0.39% arsenic, and 0.22% tellurium. The test results showed that the direct recovery rate of antimony was 90.7% and the tellurium removal rate was 85.5%.

Claims

1. A method for deep tellurium removal from antimony smelting by pyrometallurgy, characterized in that: The following steps are involved: (1) Determine the weight of the tellurium removal reagent according to the tellurium content in the crude antimony, and heat to melt the antimony; (2) After heating to a certain temperature to melt the antimony, add the tellurium removal agent and stir with compressed air; (3) After the reaction is completed, the slag is removed from the furnace and the antimony and slag are separated.

2. The method for deep tellurium removal from pyrometallurgical antimony smelting according to claim 1, characterized in that: In step (1), the tellurium content in the crude antimony is 50ppm-350ppm.

3. The method for deep tellurium removal from pyrometallurgical antimony smelting according to claim 1 or 2, characterized in that: In step (1), the weight of the tellurium removal reagent: the weight of the tellurium contained in the crude antimony = 150-300:

1.

4. The method for deep tellurium removal from pyrometallurgical antimony smelting according to claim 1 or 2, characterized in that: In step (1), the specific operation of heating and melting antimony is: heating the crude antimony to 800-900° C. to melt the crude antimony into antimony water.

5. The method for deep tellurium removal from pyrometallurgical antimony smelting according to claim 1 or 2, characterized in that: In step (2), the tellurium removal reagent is a mixture of reagent A and reagent B, wherein A is sodium hydroxide and B is potassium hydroxide.

6. The method for deep tellurium removal from pyrometallurgical antimony smelting according to claim 1 or 2, characterized in that: In step (2), in the tellurium removal reagent, the weight percentage of reagent A is 60-90%, and the weight percentage of reagent B is 10-40%.

7. The method for deep tellurium removal from pyrometallurgical antimony smelting according to claim 1 or 2, characterized in that: In step (2), the tellurium removal temperature is 800-900°C.

8. The method for deep tellurium removal from pyrometallurgical antimony smelting according to claim 1 or 2, characterized in that: In step (2), the tellurium removal reaction time is 40-80 minutes.