Composite spinel material for side wall insulation of aluminum electrolytic cell and preparation method thereof

Abstract

The invention relates to a composite spinel material for insulation of the side wall of an aluminium electrolysis cell and a preparation method thereof. The technical scheme is that the composite spinel material comprises the procedures of: by adopting 65-75wt% of granule, 10-20wt% of iron-oxide fine powder, 5-15wt% of zinc-oxide fine powder and 5-10wt% of alpha-Al2O3 micropowder as a mixture, adding 0.5-2.0wt% of manganese monoxide and 2.5-5.5wt% of polyvinyl alcohol, stirring, forming, drying, and insulating for 2-8 hours at the temperature of 1350-1550 DEG C to obtain the composite spinel material for insulation of the side wall of the aluminium electrolysis cell. The preparation method comprises the following steps of: byadopting 55-65wt% of iron-oxide fine powder and 35-45wt% of zinc-oxide fine powder as materials, adding 0.5-2.0wt of vanadium pentoxide fine powder and 2.0-5.0wt% of polyvinyl alcohol, mixing, forming, drying, insulating for 2-6 hours at the temperature of 1300-1500 DEG C, cooling and crushing. A product prepared by the invention has the characteristics of low cost, lower heat-conductivity coefficient, good antioxidation property and excellent electrolyte-corrosion resistance.

Description

technical field [0001] The invention belongs to the technical field of composite spinel materials for heat preservation of aluminum electrolytic cells. In particular, the invention relates to a composite spinel material for thermal insulation of the side wall of an aluminum electrolytic cell and a preparation method thereof. Background technique [0002] Si is widely used in the sidewall of the current Hall-Héroult aluminum electrolysis cell 3 N 4 Combined with SiC material masonry. Since Si 3 N 4 Combined with the high thermal conductivity of SiC material, a large amount of heat will be quickly dissipated through the side wall during the electrolysis process, so that a layer of solidified electrolyte—the side wall is formed on the surface of the side wall. Under the protection of the hearth, Si 3 N 4 Combined with SiC sidewall material, it will not be in direct contact with molten electrolyte and oxidizing gas, so a better use effect has been achieved. However, to m...

AI Technical Summary

Problems solved by technology

Since Si 3 N 4 Combined with the poor oxidation resistance of SiC sidewall materials, it will react with oxidizing gases to form SiO in the absence of furnace side protection 2 ; SiO 2 It will react with high-temperature molten electrolyte to generate gaseous SiF 4 , resulting in severe damage to the sidewall material

In addition, Si 3 N 4 Combined with the high preparation cost of SiC materials, it is not suitable for large-scale use as a material for the side wall insulation of aluminum electrolytic cells

[0004] From the above, it can be seen that the side wall of the aluminum electrolytic cell is made of Si 3 N 4 Combined with SiC material, due to its high thermal conductivity, poor oxidation resistance and electrolyte erosion resistance, it can no longer meet the stable maintenance of heat preservation on the inner wall of the aluminum electrolytic cell, and the high manufacturing cost restricts the application of new energy-saving and consumption-reducing processes for aluminum electrolysis. and development