Production method of aluminum oxide
I.Production method of aluminum oxide
There are four aluminum oxide productionmethods including alkaline method, acid method, acid- alkaline combinationmethod and hot method. The industrial production of aluminum oxide is dominatedby alkaline method, which also includes Bayer’s method, sintering method andBayer-sintering combination method.
II.Requirements for alumina production in refining of aluminum through electrolysis
There are strict quality requirementsfor purity of aluminum dioxide in refining of aluminum through electrolysissince the oxides (Fe2O3, SiO2, TiO2 and V2O5) contains elements which have moreelectropositivity elements than the aluminum and are contained in aluminumdioxide can have precipitation on the cathode, which can affect the aluminumquality. If the aluminum dioxide contains the oxides which have more electronegativityelements than aluminum, these elements will react with aluminum fluoride duringelectrolysis, which will increase the consumption of aluminum fluoride. Basedon the calculation, the increase of 0.1% Na2O in aluminum dioxide will need3.8Kg more aluminum fluorides in producing one ton aluminum.
Therefore, the aluminum oxide used inrefining aluminum through electrolysis shall have higher purity but lowerimpurity content. The quality of aluminum oxide is related to production methodand the aluminum oxide produced through Bayer’s method has higher purity thanthat in sintering method.