Method for preparing sodium metaborate with coproduct of light magnesium carbonate from low-grade ores containing magnesium and boron

Abstract

The invention provides a method for preparing sodium metaborate with a coproduct of light magnesium carbonate from low-grade ores containing magnesium and boron. The method comprises the following steps: activating the ores containing magnesium and boron to obtain an activated ore concentrate containing magnesium and boron; performing sodium modification on the activated ore concentrate containing magnesium and boron to obtain a sodium metaborate solution and alkaline hydrolysis boron mud; performing concentration crystallization on the sodium metaborate solution to obtain hydrated sodium metaborate; mixing the alkaline hydrolysis boron mud with water to obtain an alkaline hydrolysis boron mud mixture, and carbonizing the alkaline hydrolysis boron mud mixture by adopting a carbon decomposition gas to obtain a heavy magnesium solution and boron mud; and pyrolyzing the heavy magnesium solution to obtain light magnesium carbonate. According to the method, the low-grade ore concentrate containing magnesium and boron is activated at first so as to improve the activity of boron and ensure that borne can be fully extracted; meanwhile, ores containing magnesium are decomposed to generate magnesium hydroxide, which creates a condition for subsequent extraction of magnesium compounds; and by virtue of sodium modification and carbon decomposition, the extraction of boron and magnesium from the activated ore concentrate containing magnesium and boron is realized.

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 light magnesium carbonate from low-grade magnesium-boron-containing ore. Background technique [0002] Boron is an important chemical element with a natural abundance of about 0.001% in nature. It mainly exists in minerals such as natural borax, colemanite, sorbite and boronite, or in the form of liquid ore in some in some salt lakes. The utilization of boron-containing minerals in the prior art is mainly aimed at high-grade boron ore or concentrated liquid ore, and is to enrich and extract boron-containing components to extract borax or boric acid. However, for boron, a resource that is difficult to form ore, has few veins, and is in short supply of rich ore, if boron can be extracted from low-grade boron-containing ores, it will certainly be able to greatly relieve the pressure on boron demand. [0003] ...

AI Technical Summary

Problems solved by technology

Alkaline hydrolysis uses strong alkali to decompose ore under heating and pressure, but the disadvantages are obvious: boric acid or borax cannot be directly obtained; the alkali content is high, the cost is high, and the equipment is corroded; the undecomposed slag is strongly alkaline, Difficult to handle

Although the carbon-soda method can process boron mafic ore, the magnesium element associated with boron is finally mixed in the boron mud in the form of basic magnesium carbonate and cannot be recovered by a simple process, and the leached slag is boron mud, because it contains carbonic acid Sodium makes it alkaline and difficult to handle, and when boron mud is stacked in the open air, it will also appear "return to alkali" and pollute the surrounding environment

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