Extraction of Alum from Sudanese Alunite Mineral

Abstract

Abstract _ The alum was extracted from alullite mineral l(Al3 (SO4);(OH)6 , which wascollected fi"o1n U1n1nbrakiet area no1tl1 east Showak. The representative samples of alunite as a rawématerial for ahnn were taken from two depths B 3 ( about O.51n) al1d 1?; ( about 2.0m). The samples were analyzed to detennine their consfitgituents. From the analysis results it was confirmed that the sample B 3 was , more silicified compared to the sample D2. F The alullite samples were calcined at 500°C then were finely pulverized so as to facilitate the reaction, after that tlle powder was digested with sulfuric acid with different concentratio11s. The optimum time of the reaction was two hows, ill which the alum separated in a faint green solution. Then it was filtered, and crystallized from solutions of specific gravities at 35° ,45° and 60°Be‘. The pregnant solution of alum was recrystallized at the room telnperature. After that the obtained crystals were recrystallized to p1u'ify them, after which they are weighed and analyzed. After reciystallization process, the alum which insoluble in ethyl alcohol was washed with ethyl alcohol to get rid of Fe20; which decreased gradually.