Method for removing sulfur from waste lead-acid storage battery gypsum mud by using magnesium chloride

Abstract

The invention relates to a method for removing sulfur from waste lead-acid storage battery gypsum mud by using magnesium chloride, which is characterized by comprising the following steps of: firstly, decomposing a waste lead storage battery subjected to acid pouring to obtain the gypsum mud, and entering the next process for later treatment; then leaching the gypsum mud by using a magnesium chloride solution, converting lead sulfate in the gypsum mud into lead chloride entering into the solution, leaving other oxides of lead in leached slag, carrying out liquid-solid separation after leaching is ended, and smelting the leached slag at the low temperature to produce wet lead; cooling to crystallize a leachate to obtain solid lead chloride and crystallized mother liquor, smelting the solid lead chloride at low temperature to produce the wet lead, carrying out regeneration treatment on the crystallized mother liquor by using the crystallized mother liquor and then returning to the step of desulfurizing and leaching the gypsum mud; and finally, adding calcium chloride to the crystallized mother liquor to regenerate the magnesium chloride as a desulfurizing agent and simultaneously produce calcium sulfate as a byproduct. The invention has good desulfurizing effect, and the magnesium chloride as the desulfurizing agent has low price, is easy to regenerate and can be recycled. The invention does not have high requirement on production equipment, greatly reduces the production cost and has obvious advantages.

Description

Technical field: [0001] The present invention relates to a method for treating waste lead-acid batteries, in particular to a method for desulfurizing waste lead-acid battery paste, that is, using magnesium chloride as a desulfurizer to remove sulfur from waste lead-acid battery paste, It belongs to the technical field of hydrometallurgy. Background technique: [0002] With the development of the automobile and electric vehicle industry, lead has gradually become "battery metal", and the proportion of lead used in the production of lead-acid batteries is increasing year by year. The proportion of recycled lead production in western developed countries has exceeded 60% of the total lead production. The recycling rate of waste lead storage batteries in the United States has reached 98%, and the proportion of recycled lead exceeds 80%. The regenerated lead industry, which recovers lead from waste lead batteries, has received widespread attention from all over the world, and gov...

AI Technical Summary

Problems solved by technology

However, there are still some problems in using modern oxygen smelting technology to treat waste lead battery paste sludge: the paste needs to be used in conjunction with lead concentrate, the production scale is large, and the investment cost is high; although modern oxygen smelting technology solves the problem of sulfur dioxide flue gas acid production However, the pyro-method lead smelting process cannot completely eliminate the pollution of sulfur dioxide and lead-containing smoke to the environment; the modern oxygen lead smelting process can only process high-grade lead-containing raw materials, and is not suitable for processing low-grade and complex lead concentrates; There are still many problems to be solved in the process and technology of modern oxygen lead smelting

However, how to effectively recover by-products after desulfurization and how to reuse desulfurizers still needs to be further studied. These hydrometallurgical processes have long process flow, low efficiency, and high cost, and a series of problems need to be further solved.

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