The results show that the desilicating process with calcium chloride is conducted by the immediate compound, hexagonal calcium hydroaluminate, the high desilication efficiency is achieved with this emerging product with the high surface activity.
Desilication efficiency is increased with the increase of solid content of slurry, but is decreased when the solid content of slurry is increased up to a some extent in the preheating process of bauxite slurry. The relationship between reaction efficiency of Ti-containing minerals and solid content of bauxite slurry is as same as that of Si-containing minerals.
The reaction of desilication with calcium chloride is fast, in 30min desilication with calcium chloride at 90℃, the content of SiO2 is reduced to 0.0175g/L and the silica module is up to 6022. The calcium chloride is a promising agent for desilication from sodium aluminate solution.
The efficiency of desilication was increased and the entrance of vapour and the using of calcium hydroxide was decreased. The density of the alumina of decomposition surpasses 5g/l. The equipment productivity of sintering process has the new breakthrough.
The slag has a low melting point and rapid melting rate. when treating hot metal(containing Si<0.2%,P<0.06-0.07%)with this slag, we have obtained desilion efficiency approximate to 100% and maximum dephosphorization efficiency more than 87%。