Lithium sulfate leaching agent separation and purification technology

Abstract

The invention discloses a new lithium sulfate leaching agent separation and purification technology. The technology is characterized by comprising following steps: firstly, a microfiltration system is used for pretreating a lithium sulfate leaching agent, impurities and suspended matter in feed liquid are removed, and microfiltration dialyzate is obtained; secondly, the microfiltration dialyzate enters a nanofiltration system to obtain nanofiltration dialyzate and a nanofiltration concentrated solution; thirdly, the nanofiltration concentrated solution enters an electrodialysis system to be concentrated, electrodialysis concentrated water and electrodialysis contributing water are obtained, the electrodialysis concentrated water is used for MVR evaporation, and solid sulfuric acid lithium is obtained; and fourthly, the electrodialysis contributing water uses reverse osmosis for deep treatment, reverse osmosis concentrated water returns to the third step to be continuously concentrated, and reverse osmosis contributing water returns to the production technology. According to the lithium sulfate leaching agent separation and purification technology, through microfiltration, nanofiltration and electrodialysis concentration, the separation and purification aim of lithium sulfate is achieved; meanwhile, due to adding of chemical reagents, the evaporation cost is reduced, the recycling water amount is improved, and the outward zero emission of the whole system is achieved.

Description

technical field [0001] The invention relates to the field of hydrometallurgy, and particularly designs a process for separating and purifying lithium sulfate leachate. Background technique [0002] Hydrometallurgy is a process in which metal mineral raw materials are chemically treated or extracted with an organic solvent in an aqueous solution of an acidic medium or an alkaline medium, to separate impurities, and to extract metals and their compounds. Compared with pyrometallurgy, hydrometallurgy has the following advantages: 1) It has a wider scope of application. Hydrometallurgy is suitable for high, medium and low-grade raw materials, while pyrometallurgy requires high-grade raw materials; 2) Low energy consumption: wet Hydrometallurgy is generally carried out at relatively low temperature with low energy consumption, while pyrometallurgy is carried out at high temperature; 3) The process is green and environmentally friendly. During the process of extracting valuable co...

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Problems solved by technology

[0004] In the traditional treatment process, a large amount of suspended solids needs to be filtered by plate and frame, and the large amount of water treatment occupies an area, and the labor is relatively high.

The traditional process uses an evaporator to directly evaporate the leaching solution, which has a large amount of water and high cost, and due to the interference of sodium chloride, it is easy to corrode the equipment and the purity of lithium sulfate is low

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