Method for recycling tin from lead bullion

Abstract

The invention discloses a method for recycling tin from lead bullion, and belongs to the technical field of pyrogenic process and wet process combined metallurgy. The method comprises the steps that after liguation decoppering processing is carried out on the lead bullion, caustic soda, caustic soda and salt are added into the lead bullion according to the content of the tin in the lead bullion to gather and remove the tin in the lead bullion, and tin-rich slag is obtained; sodium carbonate and reduction coal are added into the tin-rich slag and all tin-containing slag produced by a lead smelting system, and the tin-rich slag and the tin-containing slag generate terne metal through reduction smelting; the terne metal is processed through vacuum distillation to obtain crude tin; highly purified precipitated tin is obtained from the crude tin through electrolytic refining of mixed acid with silicofluoric acid-sulfuric acid as an electrolytic medium, and the precipitated tin is processed through simple smelting to obtain a tin ingot product meeting the national standard. The method sets the precedent for producing tin ingot products through comprehensive utilization of tin resources obtained from lead through smelting, has the advantages of being concise in technology, high in tin product yield, low in processing cost and the like, particularly separates tin alloys through introduction of vacuum distillation, and has the significant advantages in the aspects such as energy conservation and environment protection.

Description

technical field [0001] The invention relates to a method for recovering tin from crude lead, and belongs to the technical field of metallurgy combining fire and wet methods. Background technique [0002] Lead concentrates are generally desulfurized by sintering first, converted from sulfides to oxides, and the oxides are then reduced to elemental metals, namely crude lead. Sintering blast furnaces are often used for smelting. Nowadays, oxygen-enriched molten pool smelting methods are often used to save the desulfurization link. The desulfurization and reduction reaction process is directly completed in the metallurgical furnace. Generally, the tin metal associated with lead concentrate is as low as 0.1-1%. In the production process, due to the characteristics of tin easy to oxidize and form alloys with other metals, the distribution in the smelting process is relatively scattered, and it is difficult to concentrate and recover. The smelting cost is high and the product low ...

AI Technical Summary

Problems solved by technology

The disadvantages of this recycling method are: electrolysis of the crude lead anode without tin removal, high tin content will cause more tin to precipitate in the cathode, affecting the quality of the lead, and the anode is easily passivated; the lead anode slime produced by smelting The metal separation of tin blowing slag is poor, and more metals Pb, Sb, and Ag are taken away with the slag, especially antimony, which accounts for about 13% of the total antimony amount fed; it increases the cost of secondary smelting for repeated processing; the output of tin slag Low tin content (10-20%), low price;

[0004] There are also some lead smelting enterprises that use reverberatory furnace blowing to directly enrich tin from crude lead to obtain tin blowing slag, and then repeatedly reduce and smelt tin blowing slag to obtain tin alloy with the same composition as crude solder, and then send it to the tin factory for electrolysis or other processes. Recycling; this recycling method still has defects such as high energy consumption, high environmental pollution, and high secondary smelting costs for repeated processing in the production process.

[0005] These methods are all aimed at treating the tin-containing slag at different stages in the lead smelting process to achieve the purpose of tin recovery. This treatment method has tin scattered into different intermediate or final products, which increases the tin recovery process, and tin is used as a by-product. The product will also affect the quality of the lead

Images