نوع مقاله : علمی-پژوهشی
نویسندگان
1 کارشناسی ارشد، گروه فرآوری مواد معدنی، دانشکده فنی و مهندسی، دانشگاه تربیت مدرس، تهران
2 استاد، گروه فرآوری مواد معدنی، دانشکده فنی و مهندسی، دانشگاه تربیت مدرس، تهران
3 استادیار، گروه فرآوری مواد معدنی، دانشکده فنی و مهندسی، دانشگاه تربیت مدرس، تهران
چکیده
کلیدواژهها
موضوعات
عنوان مقاله [English]
نویسندگان [English]
This paper studies the extraction of alumina from kaolin through an acidic leaching process. The kaolin sample used in this study was taken from the Zonuz kaolin mine (Iran Porcelain Industries Company) at particle sizes smaller than 150 microns. Calcination of the kaolin sample was conducted at 700 ºC for 2 hours. Aluminum was leached from calcined kaolin with an H2SO4 acid solution. Temperature and time of leaching, acid concentration, and liquid-to-solid ratio were investigated as leaching parameters. The optimal leaching conditions were considered at 90 °C, 3 hours duration, 2.5 M acid concentration, 7 ml/g liquid-to-solid ratio, and 600 rpm stirring speed, and under these conditions, aluminum leaching recovery was obtained at 94.87%. To remove the iron impurity that is transferred to the solution during leaching, the pregnant leaching solution was purified. Purification was done by solvent extraction with an organic phase containing D2EHPA as an extractant and oil as a diluent, iron removal was achieved at 88.71%. By precipitating the aluminum hydroxide from a solution of aluminum sulfate with sodium hydroxide followed by calcination of the produced aluminum hydroxide at a temperature of 1200 °C for 2 hours, alumina with a purity of 97% was produced. The total recovery of alumina obtained from the studied kaolin under optimal conditions was 89.46%, which is desirable.
کلیدواژهها [English]