Method for recovering lithium and producing high-purity boric acid or borax

Abstract

A method for recovering lithium and producing high-purity boric acid or borax comprises the steps that acid is added into a NamLinBxOy solution to adjust the pH to be 2.0-7.0, solution obtained afterpH adjustment is pumped into a membrane system, pressure is applied to the two sides of a reverse osmosis membrane to form a pressure difference, and part of water and H3BO3 in the solution are transferred from a high-voltage side to a low-pressure side through the membrane; lithium ions at the high-voltage side are enriched so as to obtain lithium-rich and poor-boron brine, and the aqueous solution on the low-pressure side is a boric acid solution containing a small quantity of lithium ions. The method is combined with a boron removal technology using a nanofiltration membrane method, the yield of the lithium ions is increased while boron elements in the brine are removed at low cost and at high efficiency, and comprehensive utilization of boron resources is achieved.

Description

technical field [0001] The present invention relates to a kind of method of reclaiming lithium and producing high-purity boric acid or borax, more particularly, relate to a kind of method from Na m Li n B x o y A method for recovering lithium in solution and producing high-purity boric acid or high-purity borax. Background technique [0002] Boron is necessary for the formation of ribonucleic acid, an essential building block of life. James Stephenson, a postdoctoral researcher at the NASA Astrobiology Institute at the University of Hawaii, said: "Boron may be important for the origin of life on Earth because it stabilizes nucleic acids, which are important components of ribonucleic acid. In early life, Ribonucleic acid is considered to be the informational precursor of deoxyribonucleic acid." [0003] The scientific community does not know enough about the absorption and metabolism of boron. Boron is easily absorbed in the diet, and most of it is excreted in urine. It ...

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Problems solved by technology

The boron removal rate of this method is low, the acid consumption is large, and the boric acid obtained has low purity and poor economic value, and at the same time causes entrainment loss of lithium and other high value-added elements

[0016] Detachment boron removal method: use meglumine-based chelating resin to remove boron in brine by ion exchange. This method removes boron thoroughly, but it is only suitable for low boron content brine. At the same time, the consumption of acid and alkali is high, and at the same time Regenerated wastewater is generated, and some lithium elements enter the recycled wastewater along with boron elements, resulting in waste of resources

[0017] Extraction boron removal method: The boron removal method is used to remove boron, and the removal rate of boron is high, but the organic solvent enters the raffinate brine, causing organic solvent pollution of the brine, and potential safety hazards of the organic solvent, which brings a greater environmental protection and safety burden

At the same time, the organic solvent enters the brine, which brings great restrictions to the subsequent separation and extraction (membrane technology, separation technology, etc. cannot be used)

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