Method for preparing large-particle lithium carbonate from salt lake lithium-rich brine

Abstract

The invention discloses a method for preparing large-particle lithium carbonate from salt lake lithium-rich brine. The method comprises the following steps: step 1, heating the salt lake lithium-richbrine to 70-85 DEG C, after heating is completed, maintaining the temperature and adding a surfactant into the salt lake lithium-rich brine; step 2, maintaining the temperature in the step 1, adding acarbonate solution into the pre-treated salt lake lithium-rich brine, and performing a reaction for 1-3 h to obtain reaction product slurry; and step 3, allowing the reaction product slurry to standfor 10-20 h, performing solid-liquid separation, washing the obtained solid particles, and performing drying to obtain the large-particle lithium carbonate. According to the method provided by the invention, the certain surfactant is added into the reaction system, so that a particle size of the lithium carbonate is increased in the precipitation process, and the obtained lithium carbonate has a particle size d(0.9) of 300-600 [mu]m; and meanwhile impurity ions adsorbed at the surface of the lithium carbonate product are reduced, and purity and a yield of a primary product are improved, wherein the purity of the primary product is >=95%.

Description

technical field [0001] The invention belongs to the technical field of inorganic chemistry, and in particular relates to a method for preparing large-grain lithium carbonate from salt lake lithium-rich brine. Background technique [0002] The process route of lithium extraction from salt lake brine can be summarized as three processes: preparation of lithium-rich brine, purification process (deep impurity removal), and lithium carbonate precipitation; the purification process is divided into two processes, namely, magnesium-lithium separation and deep removal Miscellaneous, magnesium and lithium are generally separated by ion-exchange membrane electrodialysis. (Deep impurity removal) is to carry out Li + The separation process from impurity elements will directly affect the Li 2 CO 3 Product quality and yield. The lithium carbonate precipitation process is to add alkali to the purified lithium-rich solution to precipitate Li 2 CO 3 The product process that determines L...

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Problems solved by technology

[0004] In the prior art, the purity and yield of lithium carbonate primary products are low, which causes problems such as long-term refining and carbonization process flow, high equipment requirements and high energy consumption.

The lithium carbonate particle size d (0.9) that existing technology produces: between 10-39 micron, because lithium carbonate particle is little, thereby caused yield and purity to be low, in actual production, the fluidity of lithium carbonate product is poor, "sticking wall "The phenomenon is serious, and the equipment loss rate is high

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