Method for preparing metal magnesium from magnesium mineral

Abstract

The invention relates to the method used magnesium bearing mineral to make magnesium metal. It includes the following steps: fluidizing and activating roasting for the magnesium bearing mineral to make active magnesium oxide; processing chlorination reaction distilling dehydrating for the active magnesium oxide to gain high concentration anhydrous magnesium chloride organic medium solution; using anhydrous organic medium to match to make anhydrous magnesium chloride organic solution, cool and filter; reaction crystallization under ammonia saturated conditions for the filtrate to gain magnesium chloride hex-ammoniate organic slime; filtrating to separate the magnesium chloride hex-ammoniate crystal from the organic medium filtrate back to use repeatedly; washing by ammonia saturated micro-molecule anhydrous alcohol and rapid fluidizing dryi ng to gain anhydrous magnesium chloride hex-ammoniate; setting in de-ammoniation electrolysis coupled reactor to do de-ammoniation and electrolysis to gain magnesium metal.

Description

technical field [0001] The invention relates to a technical method for producing metal magnesium, and at the same time relates to the preparation of hexammoniated magnesium chloride and the production of metal magnesium, anhydrous magnesium chloride and active magnesium oxide. Background technique [0002] At present, there are three methods for the industrial production of magnesium metal at home and abroad: (1) use magnesium-containing magnesium halide (such as bischofite, potassium carnallite, ammonium carnallite) as raw materials, after they are dehydrated, in magnesium chloride molten salt Electrolytic production of magnesium metal; (2) Dolomite is used as raw material, which is calcined and ferrosilicon and other reducing agents are subjected to thermal reduction reaction at high temperature and high vacuum to produce metal magnesium (thermal reduction method); (3) Magnesium-containing minerals are used as The raw material is chlorinated with chlorine and carbon to gen...

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Problems solved by technology

Compared with the above-mentioned process, this process has the characteristics of low-temperature dehydration and high environmental protection level; but at present, there are the following shortcomings: (1) MgCl is obtained by leaching magnesium-containing mineral hydrochloric acid 2 ·(6-8)H 2 O polyhydrated magnesium chloride, the dehydration amount of polyhydrated magnesium chloride makes the energy consumption increase, and secondly, from the angle of atom utilization economy, in this reaction process, the hydrogen atom in the hydrogen chloride is converted into the water molecule that needs energy consumption to take off, and the cost increases; (2 ) Hexaammoniated magnesium chloride deamination to obtain anhydrous magnesium chloride and electrolysis of anhydrous magnesium chloride to produce metal magnesium are divided into two sections. Anhydrous magnesium chloride is very easy to absorb water and become hydrated magnesium chloride. It is difficult to ensure that the electrolytic raw materials do not absorb water during the transportation of anhydrous magnesium chloride. Process line growth complex

The characteristics of this process: magnesium chloride is generated at low temperature in organic liquid, and the environmental protection level is high; but in the process, the output rate of magnesium chloride prepared by unit organic solvent is low (about 118 g / 1000 ml organic solvent), which makes the heat consumption of unit product increase, production efficiency decreases, unit product investment increases, and product cost is high

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