阅读说明：本技术 一种湿法除去锑氧中铅、铜、铋的工艺 (Process for removing lead, copper and bismuth in antimony oxide by wet method ) 是由 刘鹊鸣 单桃云 廖光荣 于 2020-07-15 设计创作，主要内容包括：一种湿法除去锑氧中铅、铜、铋的工艺。本发明工艺是先对待浸出的锑氧进行预处理,然后,在60～100℃下,将锑氧在硝酸中浸出铅、铜和铋,固液分离,得低铅锑氧和含铜、铋的硝酸铅溶液；所述硝酸的质量浓度为10～20%。本发明工艺采用特定浓度的硝酸对锑氧进行浸出,将锑氧中的铅、铜、铋同时溶出,得到Pb、Cu和Bi含量均低于0.1%的低铅锑氧,锑回收率高达99%。(A process for removing lead, copper and bismuth in antimony oxide by a wet method. The process comprises the steps of pretreating antimony oxide to be leached, leaching the lead, copper and bismuth from the antimony oxide in nitric acid at the temperature of 60-100 ℃, and carrying out solid-liquid separation to obtain low-lead antimony oxide and lead nitrate solution containing the copper and the bismuth; the mass concentration of the nitric acid is 10-20%. The process of the invention adopts nitric acid with specific concentration to leach antimony oxide, and lead, copper and bismuth in the antimony oxide are simultaneously dissolved out to obtain low-lead antimony oxide with Pb, Cu and Bi contents lower than 0.1%, and the antimony recovery rate reaches 99%.)

1. A process for removing lead, copper and bismuth from antimony oxide by a wet method is characterized in that antimony oxide to be leached is pretreated, then the lead, copper and bismuth are leached from the antimony oxide in nitric acid at 60-100 ℃, and solid-liquid separation is carried out to obtain low-lead antimony oxide and lead nitrate solution containing copper and bismuth; the mass concentration of the nitric acid is 10-20%.

2. The process for removing lead, copper and bismuth from antimony oxide by a wet method according to claim 1, wherein the antimony oxide is high-lead antimony oxide and comprises, by mass, 45-65% of Sb, 5-25% of Pb, 0.5% or more of Cu and 0.5% or more of Bi.

3. The process for removing lead, copper and bismuth from antimony oxide by a wet method according to claim 1 or 2, wherein the mass volume ratio of antimony oxide to nitric acid in the leaching process is 1g: 2-6 mL, and the leaching time is 2-6 h.

4. The wet process for removing lead, copper and bismuth from antimony oxide according to any one of claims 1 to 3, wherein the solid-liquid separation is performed by adopting centrifugation or filter pressing of a filter press, and then washing with nitric acid with a mass percentage concentration of 5-8%.

5. The process for removing lead, copper and bismuth from antimony oxide by a wet method according to any one of claims 1 to 4, wherein the grain size of the pretreated antimony oxide is 100-300 meshes.

6. The wet process for removing lead, copper and bismuth in antimony oxide according to any one of claims 1 to 5, further comprising: concentrating the lead nitrate solution to a specific gravity of 1.7 at 100-105 ℃ under normal pressure, carrying out hot filtration to obtain a lead nitrate crude product and a mother solution, and mixing the mother solution with a lead nitrate solution to be distilled next time and a washing solution for distillation; and distilling the obtained distilled water to prepare nitric acid for leaching.

Technical Field

The invention belongs to the technical field of non-ferrous metal antimony smelting, and particularly relates to a process for removing lead, copper and bismuth in antimony oxide by a wet method.

Background

In the smelting process of non-ferrous antimony, lead, copper and bismuth are common impurities, which seriously affect the quality of antimony products and limit the application of antimony products in industry, so the national standard of antimony products stipulates the requirements of the content of lead, copper and bismuth in antimony products. In the pyrogenic process production process of antimony, lead is removed by adopting a lead removing agent pyrogenic process, copper is removed by adopting a copper removing agent, and bismuth does not have a proper separation technology so far.

The existing fire method lead removal technology is simple to operate, but the direct yield of antimony is greatly lost in the lead removal process, and particularly antimony oxide with high lead content has higher loss rate in the lead removal process; the produced lead slag removal amount is large, lead and antimony in the lead slag are further removed, and the process is very difficult. The existing technology for removing copper from crude antimony by a pyrogenic process has the defects of incomplete removal, or large antimony loss, and does not have a proper and effective copper removal technology. The existing fire bismuth removing technology for crude antimony is not used in industrial production. Thus, although some techniques are used in the pyrometallurgical antimony smelting of copper and bismuth, these techniques have been undesirable and require improvement or innovation.

CN1062175A discloses a method for preparing silver nitrate and recovering copper, lead and antimony from lead anode slime. The key point of the method is that the method comprises the following steps: (1) leaching with nitric acid; (2) leaching the filter residue with hydrochloric acid; (3) precipitating lead from the filtrate by using sulfuric acid; (4) hydrolyzing the hydrochloric acid leaching solution; (5) washing filter residues obtained by hydrolysis with alkali; (6) carrying out hydrochloric acid silver precipitation on the filtrate after lead precipitation by sulfuric acid, (7) combining the filter residues obtained in the steps (2) and (6), and carrying out ammonia leaching, complexing and reduction to prepare silver nitrate; (8) adding alkali into the filtrate obtained in the step (5) for neutralization, and then adding sulfide for copper precipitation; (9) and (5) mixing the filtrates obtained in the steps (5) and (8), and removing arsenic to obtain clear liquid and arsenic slag. The method mainly prepares silver nitrate and secondarily separates copper, lead and antimony. Although nitric acid leaching is used, the separation effect is not good. As in the examples, when 5N nitric acid was used at a liquid-solid ratio of 5 and the reaction was carried out at 80 to 95 ℃ for 3 hours, the leaching rate of Ag was 53.66%, the leaching rate of Cu was 99.10%, the leaching rate of Sb was 12.60%, the leaching rate of As was 53.58% and the leaching rate of Pb was 98.11%. The leaching rate of lead in this example is high, but the leaching rate of antimony also reaches 12.60%, and lead nitrate and antimony nitrate are precipitated in sulfuric acid solution to different degrees.

Disclosure of Invention

The invention aims to solve the technical problem of overcoming the defects and providing a process for removing lead, copper and bismuth in antimony oxide by a wet method.

The technical scheme adopted by the invention for solving the technical problems is as follows:

a process for removing lead, copper and bismuth from antimony oxide by a wet method comprises the steps of pretreating antimony oxide to be leached, leaching the lead, copper and bismuth from the antimony oxide in nitric acid at 60-100 ℃, and carrying out solid-liquid separation to obtain low-lead antimony oxide and a lead nitrate solution containing copper and bismuth; the mass concentration of the nitric acid is 10-20%.

The purpose of the antimony oxide pretreatment is to clean coarse impurities in the antimony oxide and simultaneously crush the antimony oxide with coarse particle size.

The concentration of the nitric acid is too low, and the reaction time is too long; the concentration of the nitric acid is too high, so that the leaching rate of antimony is increased, the loss of antimony is caused, and meanwhile, lead nitrate contains higher antimony; further, if the concentration of nitric acid is too high, the nitric acid is easily volatilized, and the working environment is easily deteriorated. Therefore, the concentration of the nitric acid is strictly controlled in the leaching process, and the leaching effect is very important.

Preferably, the antimony oxide is high-lead antimony oxide, and comprises, by mass, 45-65% of Sb, 5-25% of Pb, 0.5% or more of Cu, and 0.5% or more of Bi.

Preferably, in the leaching, the mass volume ratio of the antimony oxide to the nitric acid is 1g: 2-6 mL, and the leaching time is 2-6 h.

Preferably, the solid-liquid separation mode is to adopt centrifugation or filter pressing by a filter press, and then to adopt nitric acid with the mass percentage concentration of 5-8% for washing.

Preferably, the grain size of the pretreated antimony oxide is 100-300 meshes. The leaching rate of lead is reduced due to too coarse granularity of antimony oxide, and the leaching rate of lead, copper and bismuth is reduced due to the coarse granularity, so that the purpose of separating antimony from lead, copper and bismuth is difficult to achieve.

Preferably, the process further comprises: concentrating the lead nitrate solution to a specific gravity of 1.7 at 100-105 ℃ under normal pressure, carrying out hot filtration to obtain a lead nitrate crude product and a mother solution, and mixing the mother solution with a lead nitrate solution to be distilled next time and a washing solution for distillation; the distilled water obtained by distillation is used for preparing nitric acid used in leaching.

The principle of separating lead, copper and bismuth from antimony oxide is that at the temperature of 60-100 ℃, the lead, copper and bismuth in the antimony oxide are easy to react with nitric acid to generate corresponding nitrates, and the solubilities of the nitrates are high; and the antimony oxide is rarely dissolved in the nitric acid, so that the aim of separating impurities such as lead, copper, bismuth and the like from the antimony is fulfilled. The main chemical reaction formula is as follows:

PbO+2HNO₃＝Pb(NO₃)₂+H₂O

CuO+2HNO₃＝Cu(NO₃)₂+H₂O

Bi₂O₃+2HNO₃＝Bi(NO₃)₃+H₂O

the invention has the beneficial effects that:

(1) in the process, at the temperature of 60-100 ℃, the antimony oxide is leached by using nitric acid with specific concentration, so that lead, copper and bismuth in the antimony oxide are dissolved out, low-lead antimony oxide with Sb more than 65%, Pb less than 0.1%, Cu less than or equal to 0.05% and Bi less than or equal to 0.02% is obtained, the lead removal rate is more than 98%, and the antimony recovery rate is 99%;

(2) in the preferred scheme of the invention, the lead sulfate solution is concentrated under normal pressure and filtered thermally to obtain crude lead nitrate, which can be used for refining lead nitrate products and improve the added value of the lead sulfate solution;

(3) compared with fire refining, the process has the advantages of simple whole treatment process, low treatment cost, no generation of waste gas, waste water and waste residue in the whole process and good environment.

Detailed Description

The present invention is further illustrated by the following examples, which should not be construed as limiting the scope of the invention.