Purification method of sodium carbonate solution in lithium carbonate production

Abstract

The invention discloses a purification method of a sodium carbonate solution in lithium carbonate production. The method comprises the following steps: 1, preparing a sodium carbonate solution with sodium carbonate mass percentage concentration of 25%; 2, adding solid sodium hydroxide, reacting Ca and Mg ions in the sodium carbonate solution with NaOH and precipitating completely to obtain a mixture liquid; 3, carrying out primary filtration on the mixture to obtain a primary filtration liquid; 4, carrying out depth filtration on the primary filtration liquid to realize the content of Ca and Mg no more than 10ppm in a filtrate, so as to obtain a purified sodium carbonate solution finished product; and 5, using the sodium carbonate solution finished product in lithium carbonate production process for reaction with a lithium chloride solution. The method of the invention is characterized in that the deep purification of sodium carbonate solution is added before a traditional lithium carbonate production process, in order to reduce the content of Ca and Mg ions in the industrial grade sodium carbonate product, and can be used for the preparation of lithium carbonate with battery grade standard.

Description

technical field [0001] The invention belongs to the processing method of sodium carbonate solution, be specifically related to a kind of purification method of sodium carbonate solution in lithium carbonate production. Background technique [0002] LiCl solution purified and purified in salt lake brine or LiCl solution purified after dissolution of crude lithium carbonate hydrochloric acid is used to produce lithium carbonate. One of the key technology is to use LiCl and Na 2 CO 3 Precipitation reaction between Li 2 CO 3 , the quality of the finished lithium carbonate is mainly affected by the content of Ca and Mg in the product. The traditional lithium carbonate production process such as figure 1 As shown, it is divided into Na 2 CO 3 Solution preparation, lithium precipitation, separation washing, drying and other processes. As one of the raw materials for producing lithium carbonate, Na 2 CO 3， The market is divided into different grades. From the perspective of...

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Problems solved by technology

As one of the raw materials for producing lithium carbonate, Na 2 CO 3， The market is divided into different grades. From the perspective of economy, lithium carbonate production generally adopts industrial-grade quality standard Na 2 CO 3 , but limited by its process characteristics, industrial grade Na 2 CO 3 The content of Ca and Mg in the product is relatively high and fluctuates greatly. During the LiCl solution lithium precipitation process, CaCO will inevitably 3 , MgCO 3 Impurities introduce Li 2 CO 3 products, it is difficult to control the impurity content, the product quality fluctuates, and it is difficult to break through product upgrades

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