Method for recycling boric acid and magnesium sulfate from boric acid mother solution

Abstract

The invention discloses a method for treating a magnesium carbonate mother solution obtained after the production of boric acid by a carbonation method. The method disclosed by the invention is characterized by comprising the following steps: treating the magnesium carbonate mother solution, obtained after the production of the boric acid by the carbonation method, through the following technological processes: firstly, heating the mother solution to 95 to 100 DEG C; adding a proper amount of solid ammonium carbonate into the mother solution, wherein the weight ratio of the ammonium carbonateto magnesium carbonate is (1 to 1) to (1.4 to 1); dissolving and reacting to generate magnesium ammonium carbonate; filtering and cooling a generated solution; and crystallizing and separating out themagnesium ammonium carbonate, and then carrying out spin-drying treatment. By adopting the method disclosed by the invention, 80 percent or above of the magnesium carbonate in the mother solution canbe extracted without the need of concentrating the mother solution; the production speed is accelerated; coal and power are saved; the cost is reduced; compared with a traditional concentration method, the amount of the treated mother solution is reduced by one half and equipment is saved; meanwhile, the loss caused by the fact that boron is volatilized along with steam when the mother solution is concentrated and the pollution to environment are greatly reduced; and when the method is used, a lot of low-grade boron rocks also can be sufficiently utilized and the obtained magnesium ammonium carbonate is also a very good nitrogen magnesium carbon fertilizer in agriculture.

Description

technical field [0001] The invention relates to a method for recovering boric acid and magnesium sulfate from boric acid mother liquor. Background technique [0002] Boric acid is a chemical product with a wide range of uses. At present, the carbonic acid method is generally used in the industry to produce boric acid, that is, boron magnesium ore powder is added with carbonic acid to directly produce boric acid, also known as "one-step method". In addition, large-scale industrial production usually also uses "two-step method", that is, first produces borax (Na 2 B 4 o 7 .10H 2 O), then add carbonic acid to produce boric acid with borax. The "two-step method" has complex process equipment and large production investment, and only boron in boron ore is proposed, and more than 80% of other components in boron ore become slag public hazards, which pollute the environment, and boron ore cannot be comprehensively utilized, resulting in High costs and reduced competitiveness....

AI Technical Summary

Problems solved by technology

[0004] The purpose of the present invention is to overcome the most important problem that magnesium carbonate mother liquor is difficult to handle in the process of producing boric acid by carbonic acid method, and provide a new treatment method for magnesium carbonate mother liquor after producing boric acid by carbonic acid method