SU379672A1 - METHOD OF PREPARING CHLOROMAGNY RAW MATERIALS - Google Patents

Description

one

The invention relates to the field of non-ferrous metallurgy, in particular, to the development of methods for the preparation of chlorine magnesium raw materials in the electrolytic production of magnesium.

A known method of preparing chlorine raw materials for electrolysis, including dehydration, settling and vacuuming it before entering the electrolyzer.

The proposed method is characterized in that evacuation is carried out at a residual pressure of at least 10 mm Hg. Art. and a melt temperature of 700-750 ° C.

This contributes to an increase in the rate and alignment of degassing processes and the removal of bound moisture with the rapid clarification of the melt from solid suspended magnesium oxide particles.

When evacuating chlorine-magnesium raw materials, for example carnallite, at 700-750 ° C (i.e., when it is overheated above the melting point of 210-260 ° C), the decomposition of magnesium hydroxide MgOHCl (bound moisture) occurs predominantly by the mono-molecular reaction MgOHCl-MgOl + nCIf.

The particles of solid magnesium oxide initially present in the melt play the role of “seed, ensuring the flow of pe2

shares, since the decomposition of MgOHCl should occur at the phase boundary “melt - solid. The decomposition of MgOHCl leads to the enlargement of MgO and its rapid sedimentation at the bottom of the vessel. In addition, an increase in temperature, which facilitates the reaction, reduces the viscosity of the melt, which accelerates the precipitation of MgO, and also allows the residual pressure in the apparatus to be increased to 10-30 mm Hg. Art. while ensuring greater degassing rate.

This contributes to the increase in current efficiency during the subsequent electrolysis by 3-5%.

Subject invention

A method of preparing chlorine-magnesium raw material for electrolysis, including dehydration, settling and vacuuming before entering it into the electrolyzer, characterized in that, in order to increase the speed and combine the degassing processes and remove the bound moisture with the rapid clarification of the melt from solid particulate magnesium oxide particles, under a residual pressure of at least 10 mm Hg. Art. and a melt temperature of 700-750 ° C.