APPARATUS OF SEPARATING ALUMINA AND SILICA FROM KAOLIN AND THE METHOD OF THE SAME

摘要

PURPOSE: An apparatus of separating alumina and silica is provided to produce high purity alumina and silica for LEDs and solar cells by the pyrohydrolysis of kaolin using ammonium hydrogen fluoride. CONSTITUTION: A method of separating alumina and silica from kaolin comprises the following steps: mixing kaolin (Al2Si2O5x.H2O)4) and ammonium hydrogen fluoride (NH4.HF2) (S10); separating the kaolin and the ammonium hydrogen fluoride into alumina and perlite using the pyrohydrolysis (S20); sintering the alumina (S30); and purifying and crystalizing the sintered alumina using an electron beam machine (S40). An apparatus of separating the alumina and silica from the kaolin includes a storage chamber for the kaolin and ammonium hydrogen fluoride, an evaporator, a pyrohydrolysis reactor, a washer, a crusher, a second sintering furnace, a hydrolyzer, and a silica separator. The evaporator mixes and evaporates the kaolin and the ammonium hydrogen fluoride. The pyrohydrolysis reactor conducts the pyrohydrolysis with NH4(AIF6) discharged from the evaporator. The hydrolyzer desublimates (NH4)SiF6. [Reference numerals] (AA) Kaolin Al_2Si_2O_5(H_2O)_4; (BB) Mix; (CC) Ammonium hydrogen fluoride NH_4HF_2; (DD) Aggregate; (EE) Evaporation/Crystallization; (FF) Sintered material; (GG) Sublimation; (HH) Solid residue (NH_4)AIF_6; (II) Desublimation; (JJ) Pyrohydrolysis; (KK) Sublimation NH_3,HF,H_2O; (LL) Hydrolysis/dry; (MM) Wash alkaline (AI_2O_3,Fe_2O_3)