Environment-friendly energy-saving normal pressure and temperature wet preparation process for refined bismuth

Abstract

The invention discloses an environment-friendly energy-saving normal pressure and temperature wet preparation process for refined bismuth. The process comprises the procedures of normal temperature leaching, liquid-solid separation, electrodeposition, alkali fusion and electrolysis. The process comprises the following concrete steps: placing bismuth oxide, a bismuth concentrate or a copper-bismuth concentrate in an acidic chlorine salt system at normal temperature and normal pressure, using air or oxygen as an oxidizing agent and carrying out normal temperature leaching; carrying out solid-liquid separation, i.e., directly delivering a leachate to a cyclone electrolyzer at normal temperature and normal pressure, carrying out electrolysis for 1 to 7 h under the conditions that direct voltage and current density are controlled to be 1 to 3.5 V and 150 to 800 A / m<2>, respectively, so as to obtain clear post-electrodeposition liquid and sponge bismuth and returning the post-electrodeposition liquid to the procedure of leaching for cyclic usage; subjecting sponge bismuth obtained in electrodeposition to alkali covering and melting so as to obtain crude bismuth; and allowing the crude bismuth to undergo electrolysis so as to obtain refined bismuth. According to the invention, air or oxygen is used for oxidizing leaching of a bismuth ore in the acidic chlorine salt system at normal temperature and normal pressure, cyclone electrodeposition is adopted to directly extract bismuth from the leachate, so the process can be implemented at normal temperature and normal pressure and has the advantages of simple and convenient operation, high leaching rate of the bismuth ore, low cost and environmental protection.

Description

technical field [0001] The invention belongs to the technical field of smelting and extraction of nonferrous metals, and in particular relates to an environment-friendly and energy-saving normal temperature and pressure wet process for preparing refined bismuth. Background technique [0002] Bismuth is a very rare metal in the earth's crust, ten times less than silver. In nature, it mainly exists in ores in a compound state, and most of them coexist (associate) with metal minerals such as tungsten, molybdenum, lead, tin, and copper, and rarely form deposits that can be mined independently. [0003] Among the heavy non-ferrous metals, bismuth is a low-yield and expensive metal, which needs to be separated and enriched in the process of other main metals. In addition, bismuth also often enters the by-products of other main metal refining processes, such as lead anode slime, copper smelting and cooking smoke. [0004] At room temperature, bismuth does not interact with water ...

AI Technical Summary

Problems solved by technology

Typical ones are: ① ferric chloride leaching - iron powder replacement method; ② ferric chloride leaching - diaphragm electrodeposition method; ③ ferric chloride leaching - hydrolysis bismuth precipitation method; ④ chlorine selective leaching method; ⑤ hydrochloric acid — Nitrous acid leaching method; ⑥ new chlorination hydrolysis method; ⑦ pulp electrolysis method; most of these technological processes have been tested or semi-industrial tests, only the pulp method has been applied to industrial production, and the effect is not ideal

The leaching of bismuth concentrate by the above-mentioned wet treatment adopts medium and high temperature leaching, the reagents are complicated, the cost is high, the process is long and it is not environmentally friendly

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