Novel process for producing lithium salt by aid of sulfuric acid methods

Abstract

The invention relates to a novel process for producing lithium salt by the aid of sulfuric acid methods. The novel process includes calcining and then cooling spodumene concentrate to obtain spodumene calcined sand; grinding the spodumene calcined sand to obtain spodumene mineral powder; adding sulfuric acid into the spodumene mineral powder and calcining the spodumene mineral powder to obtain acid clinker; adding calcium carbonate into the acid clinker to obtain mixtures, adding water into the mixtures and filtering the mixtures when a pH (potential of hydrogen) value of the mixtures reaches 5.5-6.0 so as to obtain lithium sulfate leach liquor with the solid content higher than 10%; filtering the lithium sulfate leach liquor by the aid of micro-filtration membranes, removing solid impurities, softening filter liquor to obtain softened filter liquor with the Li+ content of 20-25 g / L, concentrating the softened filter liquor to obtain concentrated liquor with the Li+ content of 40-05 g / L, collecting wastewater obtained after the softened filter liquor is concentrated and recycling the wastewater; adding soda saturated solution into the concentrated liquor, precipitating lithium carbonate, filtering and separating lithium carbonate precipitates, washing the calcium carbonate precipitates by the aid of hot water and drying the calcium carbonate precipitates to obtain lithium carbonate finished products.

Description

technical field [0001] The invention relates to a new process for producing lithium salt by sulfuric acid method, which belongs to the field of chemical production. Background technique [0002] Lithium is an important strategic resource material and an indispensable raw material for modern high-tech products. my country's proven total reserves of lithium resources rank second in the world, but lithium production only accounts for about 5% of the global total, and it is a net importer of lithium products. [0003] Lithium carbonate is the basic material for the production of secondary lithium salts and lithium metal products, so it has become the most used lithium product in the lithium industry, and other lithium products are basically downstream products of lithium carbonate. The production process of lithium carbonate can be divided into salt lake brine extraction and ore extraction according to the source of raw materials. At present, foreign countries mainly use the s...

AI Technical Summary

Problems solved by technology

This process determines a large amount of energy consumption, and the processing cost and difficulty are relatively large

[0010] 3) The evaporation and concentration process requires more equipment, and the maintenance cost and difficulty are higher

[0011] 4) Evaporation and concentration wastes water resources and pollutes the environment, which is not conducive to the sustainable and healthy development of enterprises