Collaborative extraction system of magnesium and lithium in salt lake brine and treatment method thereof

Abstract

The invention provides a collaborative extraction system of magnesium and lithium in salt lake brine and a treatment method thereof. The collaborative extraction system mainly comprises a spraying roasting system, a dust removing system, a pulping washing device, a solid-liquid separation device, a magnesium extracting unit, a lithium extracting unit and a smoke treatment system, wherein productsof the magnesium extracting unit comprise magnesium oxide; products of the lithium extracting unit comprise magnesium hydroxide precipitates and lithium carbonate; and the magnesium hydroxide precipitates are fed in the magnesium extracting unit for magnesium extraction. Wet reaction separation is organically coupled with pyrogenic purification; a traditional technological process for extracting salt lake brine elements is integrated to realize high-value collaborative extraction of valuable elements-magnesium and lithium in the salt lake brine; meanwhile, smoke afterheat is fully used in theextracting process to realize gradient utilization of heat; no waste water and no waste slag are generated; the tail gas emission is qualified; and the collaborative extraction system belongs to a green cleaning technological process.

Description

technical field [0001] The invention belongs to the field of salt lake brine resource extraction, and relates to a system for synergistically extracting magnesium and lithium in salt lake brine and a processing method thereof. Background technique [0002] With the gradual depletion of global mineral energy, lithium has become an ideal material for energy and lightweight alloys in the 21st century. It is known as an important element that drives the world forward and has important uses in high-energy batteries, aerospace, and nuclear fusion power generation. Magnesium is similar to lithium and has various uses of light metals. Magnesium oxide is the most important oxide, which has excellent alkali resistance, heat resistance and insulation properties, and has a wide range of uses. [0003] Salt lake brine is rich in resources and rich in a variety of valuable elements. After the salt lake brine is made into salt and extracts boron, potassium, bromine, iodine and other elemen...

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Problems solved by technology

Patent CN 1618997A provides a method for jointly extracting magnesium and lithium from salt lake brine, using ammonia and ammonium bicarbonate to precipitate magnesium in two stages to achieve effective separation and extraction of magnesium and lithium, and to produce magnesium series products and lithium carbonate. Involving the cycle of ammonia, similar to other precipitation methods, the process reliability is better, but the process flow is more complicated; patent CN106430254A discloses a method for extracting lithium from salt lake brine, which uses activated kaolin hydrochloric acid leaching to prepare aluminum salt, It is then added to salt lake brine for reaction to obtain lithium-containing precipitation, which is similar to other aluminate methods. Although the alkali consumption is low, the water volume evaporates and the treatment cost is high; patent CN 104925836A provides a method for extracting lithium from lithium-containing brine The ion exchange adsorption method has good selectivity and high recovery rate, but the high cost, short life and difficult regeneration of the adsorption resin have become the main restrictive factors; the patent CN 1335263A provides a method for carbonization to extract lithium. A precipitant is added to the salt lake brine, so that Mg 2+ and Li + Precipitate, and then make lithium precipitate and dissolve through carbonization or carbonation to achieve the effect of magnesium and lithium separation, and finally produce lithium carbonate. The carbonization method is low in cost and easy to realize industrialization, but the yield is low. In addition, there are problems with the source of carbon dioxide; patent CN 102001692A provides a cooperative extraction system for extracting lithium by salt lake brine extraction method. The extraction method used has good selectivity, but there are problems of serious equipment corrosion and loss of extractant, and the cost is high

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