Method for leaching and separating bismuth from blast furnace gas dust or/and mud

Abstract

The invention discloses a method for leaching and separating bismuth from blast furnace gas dust or / and mud. The method comprises the following steps: firstly, stirring and leaching blast furnace gas dust or / and mud according to a solid-liquid mass ratio of 1: (1-20) by using an oxalic acid-based eutectic solvent as a leaching agent to obtain a leachate and reaction residues; adjusting the pH value of the leachate by using a NaOH solution, uniformly stirring, standing to form zinc oxalate precipitate, carrying out solid-liquid separation to obtain precipitate and hydrolysate, washing and drying the precipitate to obtain a zinc oxalate byproduct, irradiating the hydrolysate by using an ultraviolet light source to enable an iron element in the hydrolysate to generate light-induced reduction reaction to form ferric oxalate precipitate, and filtering to obtain a ferric oxalate byproduct, wherein the filtrate is a high-purity bismuth-containing solution. According to the method, the high-purity bismuth-containing solution can be selectively separated from the blast furnace gas dust or / and mud so as to be used for producing a bismuth-containing compound with a high additional value, the process is simple, the leaching separation selectivity of the bismuth element is high, and the recycled product and the byproduct are good in economical efficiency.

Description

technical field [0001] The invention relates to the technical field of hydrometallurgy, in particular to a method for leaching and separating bismuth from blast furnace gas ash or / and mud. Background technique [0002] Blast furnace gas ash or / and mud is solid dust or / and wet mud obtained from fine particles along with blast furnace gas in the top of the furnace through dry or wet dust removal during the blast furnace smelting process. The chemical composition of blast furnace gas ash or / and mud is relatively complex. In addition to mainly iron, unburned carbon, aluminum and silicon oxides, it also contains a small amount of non-ferrous metal oxides such as Pb, Zn and Bi with low boiling points. Blast furnace gas ash and / or mud are generally considered to be difficult to use or have little value in use, and currently they are mainly treated or disposed of by stockpiling or landfilling. Due to the strong toxicity of the heavy metals contained in it, it is easy to cause a gre...

AI Technical Summary

Problems solved by technology

This method can recover part of bismuth, but in addition to containing a small amount of bismuth compounds in the obtained leachate, it also contains a large amount of valuable impurity metals such as iron, lead, and zinc that have not been recycled, thus causing a waste of various valuable resources. At the same time, the existence of these impurity metals also increases the difficulty of purification and separation of bismuth compounds in the subsequent leaching solution, and some bismuth that is difficult to dissolve in the form of bismuth oxide and bismuth sulfide has not been leached, resulting in a low recovery rate of bismuth.

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