The invention relates to a method for treating
pyrite cinder by combining acidic leaching with alkaline dissolving. The method mainly comprises the following steps that:
nitric acid is adopted to leach the
pyrite cinder, so that alkaline
oxide impurities containing
sulfur and
arsenic are desorbed, most of iron can still exist in a
solid phase in the form of
ferric oxide, and the iron is effectively enriched, wherein the iron
enrichment ratio is more than 90%, the
sulfur removal ratio is more than 98%, the
arsenic removal ratio is more than 99%, the
solid phase is acid-leached residue, and the
liquid phase is acid-leached liquor; when the content of
silicon dioxide is more than 15% and the total
iron content can reach about 50% in the
pyrite cinder, an alkaline dissolving treatment is needed, the alkaline-dissolved residue is
iron ore concentrate, white
carbon black is obtained after acidifying alkaline-dissolved liquor, and the
liquid phase is a
sodium chloride solution which can be used as a
raw material of
sodium hydroxide; the acid-leached liquor is added into
ammonium dihydrogen
phosphate to produce
ferric phosphate which can be used as raw materials and
ceramic raw materials of a
lithium iron phosphate electromagnetic material; and purified acid-leached liquor is obtained after carrying out
arsenic removal and can be applied to the production of
nitro compound fertilizer. With the adoption of the method for treating the pyrite cinder by combining the acidic leaching with the alkaline dissolving, the pyrite cinder can be fully and comprehensively utilized, and thus, the
resource utilization ratio is increased; and the energy-saving and emission-reduction effect is good, the method is beneficial to environment-friendliness, and the clean production in the acid making industry by using the pyrite cinder can be achieved.