Method for extracting zinc indium and recovering iron from high-iron high indium zinc concentrate

Abstract

A method for extracting zinc indium and recovering iron from high-iron high indium zinc concentrate comprises the following steps: roasting high-iron high indium zinc concentrate which comprises 13-20% of Fe and 0.05-0.25% of In to produce zinc calcine; performing neutral leaching of zinc calcine; performing hot acid reduction and leaching of the neutral leached residues; performing preneutralization of the hot acid reduced leachate by zinc oxide; performing replacement and indium deposition of the preneutralized solution by zinc powder; performing iron deposition of the solution after indium deposition by oxygen-compressed hematite to produce hematite slag with 55-65% of iron; separating sulfur concentrate and flotation tailings from the hot acid reduced leached residues by a flotation method, returning the sulfur concentrate for boiling and roasting treatment, allowing the tailings to enter a fuming furnace for reduction and volatilization treatment.

Description

technical field [0001] The invention relates to a nonferrous metal smelting process, in particular to a method for extracting zinc indium and recovering iron from high iron and high indium zinc concentrate. Background technique [0002] At present, the smelting process for extracting zinc and indium from high-iron high-indium zinc concentrate is as follows: boiling furnace desulfurization of high-iron high-indium zinc concentrate; hot acid leaching of zinc calcine; precipitation of iron indium by alum method; purification of supernatant solution and electrowinning to produce electricity Zinc-alumina slag is reduced and volatilized to recover zinc and indium. This process is referred to as "hot acid leaching-jarosite method for iron precipitation" process. In this process, zinc obtains a higher leaching rate, and iron and indium are precipitated and enriched into the jarosite slag together; Reduction and volatilization treatment is carried out in the rotary kiln to obtain zi...

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Problems solved by technology

The main disadvantages of this process are: (1) the amount of alum slag is large, and a large amount of coke needs to be consumed during the reduction and volatilization treatment in the rotary kiln, which leads to high production costs; (2) the smelting recovery rate of indium is low, and the production cost The average content of indium in the rotary kiln slag is 0.03%, which makes it impossible to recover the indium which accounts for about 10% of the total indium metal of the raw material zinc concentrate; A large amount of sulfur dioxide gas is produced, and the reduction of volatile flue gas needs to be absorbed and treated before it can be discharged up to the standard

Chinese patent CN200510031335.0 proposes to use a conventional neutral leaching method to dissolve most of the zinc that is easy to recover and exist in the form of zinc oxide into the solution, separate it from the difficult-to-handle zinc ferrite, and then subject the neutral leaching residue to high temperature Reduction and volatilization treatment, then separate zinc, indium and iron, and finally recover zinc and indium from volatilized dust. In this process, 92% of zinc and 70% of indium have been effectively recovered, but the high-temperature reduction and volatilization treatment is neutral The leaching slag has a large amount of slag, and the slag contains more than 25% zinc. The production cost of high-temperature reduction and volatilization is very high, and the recovery rate of indium smelting is low, so it is impossible to finally process high-iron iron (Fe13-20%) in industry. , Application of high indium (In0.05~0.25%) zinc concentrate

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