A method for the production of aluminium hydroxide containing aluminium oxide ores from

摘要

PURPOSE: To reduce loss of alkali and alumina and to obtain aluminum hydroxide which is hardly contaminated with silica when a liq. alumina extract from a tube reactor is desilicated and the aluminum hydroxide is deposited by specifying the extracting condition. ;CONSTITUTION: A concd. alumina-contg. ore is slurryed with a small amt. of an aq. alkali soln., and the slurry and an aq. alkali soln. preheated above the extraction temp. of alumina after being mixed with the slurry are simultaneously or the mixture is charged into a tube reactor. The alumina is extracted from the ore at 120-160°C within 10min, the insolubles are immediately separated from the liq. extract, the extract is then desilicated, and then a seed of aluminum hydroxide is added to deposit aluminum hydroxide. When the extraction temp. and time are increased above the above-mentioned values, the extraction rate of alumina is not enhanced, the elution of reactive silica is suppressed, and loss of alkali is increased.;COPYRIGHT: (C)1993,JPO&Japio