Process for preparing high purity lithium

Abstract

The invention relates to a highly pure Li preparing method, smelting, depositing and filtering the crude Li to eliminate most impurities, controlling Li liquor to uniformly and continuously flow in a vacuum distilling furnace and selectively vaporizing impurities at 450-650deg.C at pressure lower than 15MPa, and condensing and collecting Li at temperature under 150 deg.C. It adopts primary low-temperature thin layer vacuum vaporization of LI, reduces energy consumption, prolongs device service life, and has short flow, low cost, high direct yield and strong producing ability, where energy consumption is only equivalent to about 1 / 3 of that of high-temperature rectifying method. It is an effective method of preparing highly pure Li.

Description

Technical field [0001] The invention relates to a preparation method of high-purity lithium. Background technique [0002] In terms of refining high-purity lithium, the United States and the former Soviet Union have conducted vacuum purification research on lithium. The United States adopted a combined filtration-distillation method, and the former Soviet Union adopted a bubble tower, sieve plate tower, and distillation-zone fusion method. 99.9% or more. Since the 1950s, my country has successively carried out vacuum distillation and step-type continuous rectification to produce lithium with a purity of 99.99%. In 1980, it was produced by continuous distillation, and the product purity can reach 99.9%-99.99%. Relevant researches in Beijing and other places The research has studied the refining of industrial-grade metal lithium with a purity of 96%-99% to high-purity lithium with a purity of 99.9%-99.99% through vacuum distillation. At present, there are roughly two types of...

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Problems solved by technology

Its disadvantages are: a large amount of raw materials must be purified, the processing capacity is large, and the production cost is high; the other type is: lithium carbonate - lithium chloride - electrolysis - high temperature vacuum distillation, its disadvantages are high energy consumption, unstable product quality, The equipment is seriously corroded, the production capacity is small, and the direct yield is low

The main problems in the prior art are: ① unstable product quality; ② high energy consumption, 50-60Kw.h / KgLi; ③ high-temperature distillation, the temperature is controlled at about 800°C, which seriously corrodes the equipment and greatly shortens the life of the equipment ; 4. the direct yield is on the low side; 5. adopt secondary distillation (the second distillation is low temperature) to produce high-purity metal lithium

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