Method for selectively precipitating magnesium in zinc-magnesium solution

Abstract

The invention belongs to the technical field of zinc smelting, and particularly relates to a method for selectively precipitating magnesium in a zinc-magnesium solution, which comprises the following steps of: adding a pre-reaction solution into the zinc-magnesium solution, carrying out pre-reaction to obtain a pre-reaction solution, respectively forming liquid flows by the pre-reaction solution and a combined precipitator solution, and contacting and mixing the liquid flows of the pre-reaction solution and the combined precipitator solution to carry out magnesium precipitation reaction; and controlling the pH value of the liquid flow mixing system to be 9.5-11, and then carrying out solid-liquid separation to obtain magnesium slag and zinc liquid. The method has excellent zinc and magnesium selectivity, magnesium can be selectively precipitated, and high-purity zinc liquid can be obtained at a high recovery rate.

Description

technical field [0001] The invention relates to the field of hydrometallurgy, in particular to a method for selectively precipitating magnesium in a zinc-magnesium solution. Background technique [0002] In the traditional zinc hydrometallurgy process, after roasting and leaching, most magnesium enters the zinc hydrometallurgy process in the form of ions such as common sulfate and nitrate, and is gradually enriched. In the magnesium-zinc solution, magnesium will crystallize out in the form of magnesium sulfate dihydrate. It will lead to pipeline blockage and scaling on the tank wall during the hydrometallurgy process, and will also affect the current efficiency of the electrowinning process, increasing the energy consumption of the hydrometallurgy zinc smelting process. At the same time, complexation will occur with fluoride ions, which will greatly increase the concentration of fluoride ions in the solution. [0003] At present, the commonly used magnesium removal methods...

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Problems solved by technology

However, many extractants also extract other impurity ions while extracting zinc, and the residual problem of the extractant is also likely to cause a series of problems such as burning boards. Therefore, finding an efficient and low-cost zinc extractant becomes the key to the solvent extraction method.

[0009] At present, there is no effective method for extracting magnesium in the hydrometallurgy process. Generally, hydrometallurgy factories employ special laborers to use some mechanical means to regularly deal with blocked pipelines. The crystallization of magnesium sulfate in the process is relatively simple to operate and the process is short, but it cannot completely solve the harm caused by impurity magnesium, and it needs to be processed in a fixed period. During the processing, the surface of the pipeline is damaged due to improper operation or too strong crystallization , so that the inner wall of the pipeline is more uneven, and the solution flows through the uneven place to form crystals more easily and block the pipeline. At this time, more labor and material resources are required to solve the harm caused by magnesium, and then the zinc hydrometallurgy The production cost has been greatly increased. It is understood that the various conveying pipelines of the wet zinc smelting plant need to be cleaned every month, and the filter cloth on the filter press used for filtration needs to be cleaned every day

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