Method for extracting lithium carbonate and aluminum hydroxide through lepidolite and fly ash

Abstract

The invention provides a method for extracting lithium carbonate and aluminum hydroxide through lepidolite and fly ash. The method comprises the steps of an extraction process and calcination additive obtaining. The extraction process comprises the substeps of powder sieving, mixing, prilling, calcination, soaking, alumina precipitation, separation, impurity removal, concentration, lithium precipitation, drying, crushing and the like; a calcination additive is composed of active CaCO3, Na2SO4, NaOH, CaO and the like, the calcination conversion ratio and leaching rate of Li and Al can be increased, and the comprehensive utilization rate of lithium carbonate is increased and can reach 85% or above. Accordingly, the production process is simple, free of pollution and high in comprehensive utilization rate, and the method is suitable for large-scale industrial production.

Description

technical field [0001] The invention relates to a method for extracting lithium carbonate and aluminum hydroxide by using lepidolite and fly ash. Background technique [0002] In recent years, with the promotion of new energy vehicles and the development of nuclear power generation, the demand for lithium and its compounds has grown rapidly. At present, the raw materials for extracting lithium are mainly spodumene and lithium-containing brine. Using spodumene to extract lithium not only relies on imported raw materials, high prices, and difficulty in obtaining it, but also has problems such as high energy consumption, high equipment requirements, and high cost of ultrafine powder removal; lithium extraction from brine is subject to technical reasons, making magnesium and boron Extraction is difficult, the production process is complicated, and the product purity after extraction is not high. [0003] Lepidolite is the tailings after flotation of tantalum-niobium ore. Curre...

AI Technical Summary

Problems solved by technology

At present, there is a large backlog of lepidolite in my country, especially lepidolite with a lithium oxide content of less than 3.5%, reaching more than 300,000 tons in stock, which is a serious waste of limited mineral resources

With the development of the power industry, the discharge of fly ash has increased sharply, calculated in billions of tons per year, which has brought a series of environmental problems. Although my country has carried out comprehensive utilization of various fly ash, the common one is the preparation into alumina or silica products, but a large number of calcination processes are used in production and processing, causing secondary pollution, which can be said to have little effect

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