Method for producing sodium pyroantimonate from high-boiling-point substances and low-boiling-point substances in preparation process of high-purity antimony

Abstract

The invention discloses a method for producing sodium pyroantimonate from high and low boiling residues in the preparation process of high-purity antimony, and relates to the field of non-ferrous metal metallurgy. According to the method, the high-boiling-point substance and the low-boiling-point substance produced in the production process of the high-purity antimony are subjected to the steps of distillation, chlorination, hydrolysis, aging, neutralization, drying and the like to directly produce the sodium pyroantimonate product, so that direct productization of the high-boiling-point substance and the low-boiling-point substance in the preparation process of the high-purity antimony is realized, and the direct yield of the antimony in the production process of the high-purity antimony is improved; the method avoids on-site stockpiling of the high-purity antimony high-low boiling residues and environmental pollution, is simple to operate, and has good economic benefits.

Description

Technical Field

[0001] The invention belongs to the field of nonferrous metal smelting, and in particular relates to a method for producing sodium pyroantimonate from high-boiling and low-boiling substances in the process of preparing high-purity antimony. Background Art

[0002] Sodium antimony pyrophosphate, a widely used antimony salt, is primarily used as a flame retardant in textiles and plastics, a glass clarifier, a whitening agent for enamel products, an opacifying agent, and an opaque filler in casting paints. Demand for sodium antimony pyrophosphate has increased significantly, particularly since the glass industry gradually banned arsenic trioxide as a clarifier. The primary raw material for sodium antimony pyrophosphate in my country is stibnite. Production processes are generally categorized into pyrometallurgical and hydrometallurgical processes. Compared to pyrometallurgical processes, the hydrometallurgical process offers more complete reaction, higher conversion rates, lower energy consumption, and more stable product quality. Currently, the hydrometallurgical process is the mainstream process for producing sodium antimony pyrophosphate in my country.

[0003] The primary production process for 5-7N high-purity antimony in my country is the "chlorination-distillation-reduction" process. Using metallic antimony as the raw material, chlorination, distillation, and reduction processes produce 5-7N high-purity antimony. The distillation process produces high- and low-boiling-point products, primarily antimony trichloride, along with impurities such as arsenic and copper. These products are hazardous chemicals and contain impurities, making them unsuitable for sale as finished products. Furthermore, their strong corrosiveness makes them unsuitable for long-term storage. The primary treatment method for these products within the industry is direct hydrolysis to produce antimony oxychloride, which is then sold or returned to the antimony pyrometallurgical smelting system to produce metallic antimony or antimony white. The antimony white produced is then used to produce sodium antimonite pyrophosphate. The main drawbacks of this treatment method are the large wastewater volume and high treatment costs.

[0004] Therefore, how to directly and effectively recycle and utilize the high- and low-boiling products produced in the high-purity antimony production process in the form of sodium antimony pyroate products will greatly promote the processing and development of my country's rich antimony resources and has great economic value and significance. Summary of the Invention

[0005] In order to solve the above problems, the present invention provides a method for producing sodium antimonate pyroantimonate from high-boiling-point and low-boiling-point products in the preparation process of high-purity antimony. The method directly produces the sodium antimonate pyroantimonate product by subjecting the high-boiling-point and low-boiling-point products produced in the production process of high-purity antimony to the steps of distillation, chlorination, hydrolysis, aging, neutralization, drying, etc., thereby achieving the purpose of directly converting the high-boiling-point and low-boiling-point products in the preparation process of high-purity antimony into products.

[0006] The technical solution of the present invention is achieved as follows: a method for producing sodium pyroantimonate from high- and low-boiling-point substances in the preparation of high-purity antimony, comprising the following steps: (1) Distillation: The high-boiling and low-boiling products produced during the preparation of high-purity antimony are distilled. The distillation temperature is controlled at 140-150°C and the distillation time is controlled at 4-8 hours to remove a small amount of water and arsenic trichloride from the high-boiling and low-boiling products. The different boiling points of water (100°C), AsCl3 (130°C) and SbCl3 (283°C) are used to volatilize the water and a small amount of AsCl3 in the high-boiling and low-boiling products, thereby achieving preliminary separation from SbCl3. (2) Chlorination: Slowly introduce chlorine gas into the distilled high and low boiling points for chlorination. The initial chlorination temperature is controlled at 60~90℃ to convert antimony trichloride into antimony pentachloride. Antimony trichloride reacts with chlorine to produce antimony pentachloride. The reaction equation is as follows: SbCl3+Cl2=SbCl5; (3) Hydrolysis and aging: First, mix antimony pentachloride and water in a ratio of 1:1, then add the antimony pentachloride solution into a large amount of clean water for hydrolysis. The volume ratio of antimony pentachloride solution to clean water is controlled at 1:10~15, and the hydrolysis temperature is controlled at 20~60℃. The reaction equation is as follows: SbCl5+5H2O=HSbO3↓+5HCl+2H2O After the hydrolysis is completed, aging is carried out. The aging time is controlled to be 3 to 7 days, and the aging temperature is controlled at room temperature. The initial product of the hydrolysis is mainly in the form of amorphous antimony oxide. The purpose of aging is mainly to transform the crystal form of the hydrolysis product from amorphous to crystalline, which is convenient for filtration and neutralization steps. (4) Neutralization: Filter the aged solution, and then gradually add the precipitate to the sodium hydroxide solution. The concentration of the sodium hydroxide solution is controlled at 8-10%, the liquid-to-solid ratio is controlled at 4-5:1, the neutralization temperature is controlled at 60-90°C, and the neutralization reaction time is controlled at 2-4 hours. The precipitate reacts with the sodium hydroxide solution to generate sodium pyroantimonate. The reaction equation is as follows: HSbO3+NaOH+2H2O=NaSb(OH)6; Washing and drying: The sodium pyroantimonate produced after the neutralization reaction is washed and dried before packaging.

[0007] The beneficial effects of the present invention are: (1) the method of the present invention can realize the effective recovery and utilization of high-boiling and low-boiling products in the preparation process of high-purity antimony, and the direct recovery rate of antimony can be increased by about 5 to 8 percentage points compared with the traditional treatment process; (2) This method has a high level of resource utilization, achieving the goal of directly converting high- and low-boiling products in the preparation of high-purity antimony. Compared with traditional processes, the process flow is greatly shortened; (3) The present invention is simple to operate, the production process is easy to implement, and the production cost is low. BRIEF DESCRIPTION OF THE DRAWINGS

[0008] Figure 1It is a process flow chart of the present invention. DETAILED DESCRIPTION

[0009] For better understanding and implementation, a method for producing sodium pyroantimonate from high- and low-boiling-point substances in the preparation of high-purity antimony is described in detail below with reference to the accompanying drawings: Example 1: The high and low boiling point components produced during the preparation of high-purity antimony are shown in the following table: materials Sb (%) As (%) Cl（%） High and low boiling substances 52.21 0.02 45.41 The high-boiling and low-boiling substances are distilled at 150°C for 4 hours. After the distillation, when the solution temperature drops to 60°C, chlorine gas is slowly introduced for chlorination. When excess chlorine gas is in the buffer bottle, the chlorination is stopped. After the chlorination is completed, the antimony pentachloride solution is first mixed with clean water in a 1:1 ratio, and then added to clean water for hydrolysis. The volume ratio of antimony pentachloride solution to water is 1:10, and the hydrolysis temperature is controlled at 25°C. After the hydrolysis is completed, the solution is aged for 7 days and then filtered. The precipitate produced by filtration is added to sodium hydroxide solution for neutralization. During the neutralization process, the sodium hydroxide solution concentration is controlled at 10%, the liquid-to-solid ratio is controlled at 4:1, and the solution temperature is controlled at 70°C. After reacting for 2 hours, the solution is filtered. The precipitate is washed with water and dried to obtain the sodium pyroantimonate product (in compliance with YS / T 22-2010).

[0010] After the above steps, the amount of sodium pyroantimonate product produced is as follows: Example 2

[0011] The components of high and low boiling points produced during the preparation of high-purity antimony are shown in the following table: materials Sb (%) As (%) Cl（%） High and low boiling substances 52.08 0.04 45.32 The high-boiling and low-boiling substances are distilled at 145°C for 6 hours. After the distillation, when the solution temperature drops to 65°C, chlorine gas is slowly introduced for chlorination. When excess chlorine gas is in the buffer bottle, the chlorination is stopped. After the chlorination is completed, the antimony pentachloride solution is first mixed with clean water in a 1:1 ratio, and then added to clean water for hydrolysis. The volume ratio of antimony pentachloride solution to water is 1:15, and the hydrolysis temperature is controlled at 40°C. After the hydrolysis is completed, the solution is aged for 4 days and then filtered. The precipitate produced by filtration is added to sodium hydroxide solution for neutralization. During the neutralization process, the sodium hydroxide solution concentration is controlled at 10%, the liquid-to-solid ratio is controlled at 5:1, and the solution temperature is controlled at 80°C. After reacting for 4 hours, the solution is filtered. The precipitate is washed with water and dried to obtain the sodium pyroantimonate product (in compliance with YS / T 22-2010).

[0012] After the above steps, the amount of sodium pyroantimonate product produced is as follows: Example 3

[0013] The components of high and low boiling points produced during the preparation of high-purity antimony are shown in the following table: materials Sb (%) As (%) Cl（%） High and low boiling substances 52.34 0.02 45.52 The high-boiling and low-boiling substances are distilled at 140°C for 8 hours. After the distillation, when the solution temperature drops to 75°C, chlorine gas is slowly introduced for chlorination. When excess chlorine gas is in the buffer bottle, the chlorination is stopped. After the chlorination is completed, the antimony pentachloride solution is first mixed with clean water in a 1:1 ratio, and then added to clean water for hydrolysis. The volume ratio of antimony pentachloride solution to water is 1:12, and the hydrolysis temperature is controlled at 55°C. After the hydrolysis is completed, the solution is aged for 7 days and then filtered. The precipitate produced by filtration is added to sodium hydroxide solution for neutralization. During the neutralization process, the sodium hydroxide solution concentration is controlled at 8%, the liquid-to-solid ratio is controlled at 4:1, and the solution temperature is controlled at 90°C. After reacting for 2 hours, the solution is filtered. The precipitate is washed with water and dried to obtain the sodium pyroantimonate product (in compliance with YS / T 22-2010).

[0014] After the above steps, the amount of sodium pyroantimonate product produced is as follows:

Claims

1. A method for producing sodium pyroantimonate from high and low boiling points in the preparation of high-purity antimony, characterized in that The following steps are involved: (1) Distillation: Distill the high-boiling and low-boiling products produced during the preparation of high-purity antimony. The distillation temperature is controlled at 140-150°C and the distillation time is controlled at 4-8 hours to remove a small amount of water and arsenic trichloride from the high-boiling and low-boiling products. (2) Chlorination: Slowly introduce chlorine gas into the distilled high and low boiling points for chlorination. The initial chlorination temperature is controlled at 60-90°C to convert antimony trichloride into antimony pentachloride. (3) Hydrolysis and aging: first, mix antimony pentachloride and water in a ratio of 1:1, then add the antimony pentachloride solution into a large amount of clean water for hydrolysis. The volume ratio of antimony pentachloride solution to clean water is controlled at 1:10~15, and the hydrolysis temperature is controlled at 20~60℃. After the hydrolysis is completed, aging is carried out. The aging time is controlled at 3~7 days, and the aging temperature is controlled at room temperature. (4) Neutralization: Filter the aged solution, and then gradually add the precipitate to a sodium hydroxide solution. The concentration of the sodium hydroxide solution is controlled at 8-10%, the liquid-to-solid ratio is controlled at 4-5:1, the neutralization temperature is controlled at 60-90°C, and the neutralization reaction time is controlled at 2-4 hours. The precipitate reacts with the sodium hydroxide solution to generate sodium pyroantimonate. (5) Washing and drying: The sodium pyroantimonate produced after the neutralization reaction is washed and dried before packaging.

Images