Microbial refinement of kaolin by ironreducing bacteria
01/11/2002#0183;#32;To analyze the total iron content containing the kaolin sample, iron was extracted from the kaolin by heating it for 15 to 20 min in 6N HCl. 10% hydroxylamine hydrochloride was added to this extract to reduce Fe(III) to Fe(II), and then total iron content was determined by the ophenanthroline method (Furman, 1975).