Technology for extracting lithium from lithium-containing alkaline brine based on centrifugal extractor

Abstract

The invention discloses a technology for extracting lithium from lithium-containing alkaline brine based on a centrifugal extractor. The technology comprises the following steps including extraction water phase providing, extraction organic phase providing, the extraction step, the washing step, the reverse extraction step and the regeneration step. The brand new extraction system is adopted in the technology, the lithium is extracted from the lithium-containing alkaline brine system, and the extraction-washing-reverse-extraction-regeneration total process technology based on the centrifugal extractor is determined for the first time instead of staying on the basic study on the extraction workshop section, the series, the flow rate, reagent concentration and other technology parameters ofevery workshop section to which the extraction system is adaptive are determined finally, and the industrial production technology path based on the centrifugal extractor is provided. The technology for extracting lithium from lithium-containing alkaline brine is particularly suitable for a filter liquor system generated in the lithium carbonate product preparing process through a lithium chloridesolution, accordingly, the lithium is further extracted from the lithium chloride solution, real comprehensive cyclic utilization of salt lake brine is achieved, and practical significance is achieved.

Description

technical field [0001] The invention belongs to the technical field of salt lake chemical industry, and specifically relates to a process for extracting lithium from lithium-containing alkaline brine based on a centrifugal extractor. Background technique [0002] Lithium is the lightest metal in nature and has extremely strong electrochemical activity. Its metals and compounds are widely used in glass, ceramics, aluminum smelting, organic chemical industry, aerospace, nuclear fusion and other industries and fields as thermonuclear fusion (hydrogen bomb) explosives, high-performance propellant for aircraft, rockets and missiles, and shielding materials for nuclear reactors. Lithium batteries have 4 to 30 times higher energy storage than ordinary batteries and have good performance. They have long been used as propulsion for torpedoes, submarines, and spacecraft. Lithium-aluminum and lithium-magnesium alloys are high-strength and light-weight, and are good materials for aeros...

AI Technical Summary

Problems solved by technology

[0003] At present, effective methods for extracting lithium from salt lake brine include solvent extraction, and solvent extraction inevitably uses FeCl 3 As a co-extraction agent, the density of the extracted organic phase is increased, and the density difference between the two phases is reduced, which requires higher extraction and separation equipment; at the same time, the introduction of FeCl 3 Finally, it is very difficult to regenerate the extractant with alkali, and very precise flow control is required, otherwise it will cause problems such as a decrease in extraction rate or emulsification failure of the extractant

In addition, since the organic phase contains co-extractant FeCl 3 , this requires that the extraction material (brine) must be kept weakly acidic, otherwise Fe will be hydrolyzed, and the brine entering the extraction section must be acidified. Lithium and boron generally exist together in Qinghai Salt Lake, and boric acid must be precipitated during the acidification process. Filtration is required, so it is not suitable for the extraction of lithium in alkaline systems

Moreover, most of the extraction agents currently used for lithium can only achieve the separation of lithium and magnesium, and the extraction effect for alkali metal systems is very poor.

In short, due to the existence of the co-extraction agent FeCl3, the process flow is more complicated, the process control is very difficult, and the investment in equipment is large.

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