Method for joint production of zinc sulphate monohydrate and zinc sulphate heptahydrate

Abstract

The invention discloses a method for joint production of zinc sulphate monohydrate and zinc sulphate heptahydrate. The method for preparing zinc sulfate in the prior art has the defects of higher production cost, complicated and tedious process, needs of evaporative crystallization, high investment in equipment and high energy consumption. The method comprises the following steps: extracting a zinc-containing solution to obtain a loaded organic phase; reversely extracting the loaded organic phase to obtain a zinc sulfate solution; dividing the solution subjected to oil removal into two parts;continuously adding sulfuric acid into one part of the solution and controlling the stirring speed and aging time and crystallizing zinc sulphate monohydrate, separating out, filtering, washing and drying to obtain a high-purity zinc sulphate monohydrate product; preparing zinc sulphate heptahydrate by adopting concentrated crystallization, taking one part of the obtained zinc sulphate heptahydrate to prepare a saturated zinc sulfate solution for washing zinc sulphate monohydrate and drying the other part of the obtained zinc sulphate heptahydrate to obtain a finished product of zinc sulphateheptahydrate. The method disclosed by the invention has the advantages of lower production cost, simpler process flow, less investment and the like.

Description

technical field [0001] The invention relates to a preparation process of zinc sulfate, in particular to a method for jointly producing zinc sulfate monohydrate and zinc sulfate heptahydrate through leaching, extraction, stripping and other processes for zinc-containing materials. Background technique [0002] At present, the process for preparing zinc sulfate at home and abroad can roughly include several steps such as acid dissolution, impurity removal, evaporation crystallization, and drying. This process has the following problems in the production process: First, a large amount of zinc is required in the impurity removal process. Second, the iron and ferrous iron obtained in the leaching process need to be oxidized to remove iron, which is a complex and cumbersome process; third, to obtain zinc sulfate monohydrate, evaporation crystallization is required, which requires large equipment investment and energy consumption. high. [0003] Therefore, it has become a necessit...

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Problems solved by technology

[0002] At present, the process for preparing zinc sulfate at home and abroad can roughly include several steps such as acid dissolution, impurity removal, evaporation crystallization, and drying. This process has the following problems in the production process: First, a large amount of zinc is required in the impurity removal process. Second, the iron and ferrous iron obtained in the leaching process need to be oxidized to remove iron, which is a complex and cumbersome process; third, to obtain zinc sulfate monohydrate, evaporation crystallization is required, which requires large equipment investment and energy consumption. high

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