Method for extracting lithium by drying lepidolite with waste heat

Abstract

The invention provides a method for extracting lithium salt by drying lepidolite with waste heat. The method takes lepidolite as a raw material, adopts a rotary kiln to roast lepidolite, and comprisesthe processes of raw material crushing, waste heat drying, roasting in the rotary kiln, leaching, filtering, concentrating, lithium settling and the like. By fully utilizing the waste heat of the rotary kiln, dried lepidolite is mixed with salt and other auxiliary materials, so content of water of the obtained mixed material is 4-5% so that the uniform mixing of the mixed material with the acid is facilitated, and it is not easy to raise dust; the waste heat of the rotary kiln is fully utilized without additional fuel for drying the lepidolite, so that the energy consumption can be saved by 20-30%; the rubidium and cesium recovery rate is high and can reach 5-6 times that of an existing process; therefore, the comprehensive development and utilization rate of the lepidolite is improved.

Description

Technical field: [0001] The invention relates to a method for extracting lithium from lepidolite, in particular to a method for extracting lithium salt by drying lepidolite with waste heat. Background technique: [0002] Lepidolite is an important mineral resource, which is rich in rare metal materials, such as lithium, sodium, potassium, rubidium, cesium, aluminum, etc. As the world's energy becomes increasingly tense, the development and utilization of new energy is a common issue in the world. Lithium battery new energy, as one of the important industries for the development of new energy, has been paid more and more attention by various countries; lithium and its salts lithium carbonate, lithium sulfate, etc. Salt is the basic raw material product of the lithium battery new energy industry, and lepidolite contains lithium metal, the basic material of the lithium battery new energy industry, so the development and application of lepidolite has become a hot topic today. I...

AI Technical Summary

Problems solved by technology

There are following defects in this method, the one, the energy consumption is high, there must be separate drying treatment system to lepidolite, simultaneously in the lepidolite, the recovery rate of rubidium and cesium is low, and the recovery rate of rubidium and cesium is less than 10%.

Second, because the residual heat of the rotary kiln is not enough to dry all the required lepidolite, it is often necessary to add additional fuel to dry the lepidolite. Generally, the moisture content of the dried lepidolite is less than 1%. It is easy to raise dust and cause environmental pollution; on the other hand, the single calcination method and the stirring and mixing method of the extract have a great influence on the lithium extraction rate of lepidolite preparation

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