Method for producing high-purity magnesium hydroxide, high-purity magnesium oxide and high-purity magnesia series magnesium products by using salt lake brine

Abstract

The invention discloses a method for producing high-purity magnesium hydroxide, high-purity magnesium oxide and high-purity magnesia series magnesium products by using salt lake brine. Purified salt lake brine is used as a raw material, high-purity magnesium hydroxide and high-purity basic magnesium carbonate are respectively prepared by two-stage magnesium precipitation reaction of ammonia and ammonium bicarbonate, and the total conversion efficiency of magnesium reaches 97-98%. The high-purity magnesium hydroxide is further processed to produce high-purity ultrafine magnesium hydroxide, high-purity heavy magnesium oxide, high-purity ultrafine magnesium oxide, high-purity sintered magnesia, high-purity fused magnesia and other products; and the high-purity light magnesium oxide product isproduced by further processing the high-purity basic magnesium carbonate. Ammonia vapor is obtained from an ammonium chloride mother liquor, obtained after basic magnesium carbonate is separated through two-stage magnesium precipitation, by adopting a lime milk reaction ammonia distillation process, and the ammonia vapor is conveyed into a system for producing magnesium hydroxide through one-stage magnesium precipitation reaction after being cooled by a corrugated pipe condenser and compressed and pressurized by an ammonia compressor, so that cyclic utilization of ammonia is realized. An ammonia distillation waste liquid is used for recovering high-quality anhydrous calcium chloride byproduct.

Description

technical field [0001] The invention relates to the technical field of chemical product preparation, in particular to a method for producing a series of magnesium products such as high-purity magnesium hydroxide, high-purity magnesium oxide and high-purity magnesia. Background technique [0002] my country is a country rich in salt lake resources. According to incomplete statistics, the area is greater than 1km 2 There are 813 inland salt lakes in China, mainly distributed in Inner Mongolia, Xinjiang, Qinghai, Tibet and other places. They are rich in salt lake resources such as potassium, sodium, magnesium, lithium, and boron, and the resource reserves are very huge. According to relevant reports, the reserves of sodium salts are hundreds of billions of tons, the reserves of magnesium salts are billions of tons, the reserves of potassium salts are hundreds of millions of tons, and the reserves of borate and lithium salts are tens of millions of tons. In recent years, in the...

AI Technical Summary

Problems solved by technology

What is more serious is that the magnesium hydroxide particles obtained by the direct reaction of seawater and underground brine raw materials with milk of lime are fine, and the filtration performance is very poor, so the production efficiency is low

Therefore, the current production of seawater magnesia in Japan and underground brine magnesia in the Netherlands, the United States, and Mexico has shrunk greatly

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