Method for producing high-purity magnesium hydroxide, high-purity magnesium oxide and high-purity magnesia series magnesium products from 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 from salt lake brine. The purified salt lake brine is used as raw material, and ammonia and ammonium bicarbonate are used for two-stage magnesium precipitation reactions, respectively. High-purity magnesium hydroxide and high-purity basic magnesium carbonate are produced, and the total conversion efficiency of magnesium reaches 97% to 98%. High-purity magnesium hydroxide is further processed to produce high-purity ultra-fine magnesium hydroxide, high-purity heavy magnesium oxide, high-purity ultra-fine magnesium oxide, high-purity sintered magnesia and high-purity fused magnesia and other products; high-purity basic magnesium carbonate is produced through further processing. Pure light magnesium oxide product. The ammonium chloride mother liquor obtained after the separation of basic magnesium carbonate in the second stage of magnesium sinking is used to react ammonia with milk of lime to obtain ammonia vapor, which is cooled by the bellows condenser and compressed by the ammonia compressor, and then transported to the first stage of magnesium sinking In the reaction production system of magnesium hydroxide, the recycling of ammonia is realized. Ammonia distillation waste liquid is used to recover high-quality anhydrous calcium chloride by-product.

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

Images