Experimental Study On The Drying Property Of Aluminum Fluoride

Anhydrous aluminum fluoride is an important additive in electrolysis aluminum production, and its water content has a direct effect on the cost and operating environment. This paper, aimed at the problem of drying aluminum fluoride trihydrate, studied the most possible binding format of crystal water, and hereby deduced the process of crystal water dehydration. The effect of drying temperature and heating rate on the aluminum fluoride dehydration was studied by thermogravimetry experiments. The dehydration mechanism and isothermal kinetics of the dewatering of aluminum fluoride crystal hydrates were investigated also by TG-DTG analysis, it also proved that the dehydration process obtained from crystal structure analyse was true.It was obtained that a higher temperature would lead to higher pyrohydrolysis, and a higher heating rate would result in more drastic dehydration, but restrain hydrolysis, so a lower limit temperature of getting rid of crystal water entirely and a higher heating rate should be adopted when drying aluminum fluoride trihydrate.