Method for preparing sodium metaborate with sodium perborate byproduct from low-grade ludwigite

Abstract

The invention discloses a method for preparing sodium metaborate with a sodium perborate byproduct from low-grade ludwigite. The method comprises the following steps: (1) boron ore concentrate powderis obtained through a mineral processing process; (2) sodium hydroxide and water are added according to the mass ratio of the sodium hydroxide to the boron ore concentrate powder to the water of 1:(1-1.2):(3-4); (3) alkaline hydrolysis is performed on the boron ore concentrate powder at the pressure of 0.5-0.6 MPa and the temperature of 155-160 DEG C, a reaction is performed for 2 h, and thereforea sodium metaborate solution is obtained; (4) after the reaction is completed, plate frame filtration is performed, and a crystallization liquid enters a crystallization tank; and plate frame filtration is performed, and a filtrate returns to the crystallization tank; (5) activated carbon is added into the filtrate, the filtrate is subjected to heat exchange and cooling through a heat exchanger,and the obtained filtrate is sent to a material preparing tank in the preparation process of the sodium perborate; and (6) a preparation process of the sodium perborate is performed: finally, materials are mixed according to a ratio after the sodium perborate product is crystallized so to improve the product stability. The method provided by the invention has the advantages of shortening an overall production process and saving a large amount of costs; and impurity removal of the product is more thorough, and the comprehensive utilization rate of the low-grade ludwigite is improved compared with a usual process.

Description

technical field [0001] The invention relates to the technical field of ore element extraction, in particular to a method for preparing sodium metaborate and co-producing sodium perborate from low-grade magnesium-boron-containing concentrate. Background technique [0002] Boron is an important chemical raw material. The natural abundance in nature is about 0.001%. It mainly exists as minerals such as borax, colemanite, sorbite and boronite. It exists in the form of liquid ore in some salt lakes. There is also a certain concentration of boron in seawater. The utilization of boron-containing minerals in the prior art is mainly aimed at high-grade boron ore or concentrated liquid ore, enriching and extracting boron-containing components to extract borax or boric acid. However, for boron ore, a mineral resource that is difficult to form ore, has few ore veins, and rich ore is in short supply, if boron can be extracted from low-grade boron-containing ores, the pressure on boron d...

AI Technical Summary

Problems solved by technology

Roasting a large amount of mineral powder in this technology consumes huge energy. In addition, coal combustion produces a large amount of waste gas, which has a great impact on the environment. At the same time, the extraction rate of boron only reaches 80%-85%. New processes must be used to change the status quo, reduce pollution and reduce waste gas emissions. Simultaneously improve the utilization rate of boron