Experimental Research On Comprehensive Recovery Of Polymetallic Iron Ore By Beneficiation

The polymetallic iron ores having huge reserves and often associating with a large number of useful components,the recovery technique for this kind of ores are often complicated because of the complex composition, minerals mutual embedded, nonuniform dissemination size, the overgrinding of minerals during mineral monomeric liberation, fine mud covers the formation, the flotability of minerals crisscross overlap.In order to get theoretical basis for comprehensive recovery of this ore, the process mineralogy, the reasonable ore separation process and appropriate pharmaceutical systems in combination with the nature of the ore, and the quantity and quality of closed circuit calculation are all researched in this thesis.This ore belongs to skarn-type polymetallic iron ore, the main useful elements are iron, copper, sulfur, accompanying gold, silver and cobalt, silicon, calcium, magnesium are the harmful elements. Magnetite and siderite are the mainly iron minerals, the oxidation ratio of copper and sulfur are high.Cobalt is mainly scattered into the pyrite in isomorphism, gold and silver is associated with other minerals.A lot of weakly magnetic iron loss in the tailing by LIMS, making some difficults for the recovery of iron.Conditions test indicate that the adding of regulators,such as copper sulphate, sodium sulphide,sodium silicate,lime,sodium carbonate, kerosene,has not obvious improvement for the copper-sulfide bulk roughing.Under the same dosage of reagents, reagent-adding in batches have more advantageous than concentrated dosing.The butyl xanthate and ammonium di-butyl dithiophosphate mixture collector has certain synergy.In contrast to conventional grinding process, the stage grinding process can improve the grade of copper concentrate 1% ~ 2%, and reduce the sulfur content of copper concentrate, but the copper recovery reduce 2% by open flowsheet test.The closed-circuit test show that the stage grinding cann't receive the expected result. The iron concentrate which sulfur content in it is below 0.1%, canbe obtained by the process of classification-reginding of coarse tailing, which can greatly disintegrate sulfide minerals intergrowth with coarse grained iron ores.The conventional grinding flowsheet is more suitable for processing this ore.By adopting the flowsheet of reagent-adding in batches, the bulk roughing flotation and then two-bulk cleaning to obtain Cu-S rough concentrate,rough concentrate dewatering and removing reagents residue,a separation of Cu-S rough concentrate by one-roughing,two-cleaning,two-scavenging in the flotation systems, after that recovery the iron from the flotation tailing by LIMS and further recovery the weakly magnetic iron concentrate by HIMS.With the conditions of the grinding fineness of -75μm 80%, a copper concentrate with copper grade of 16.47%,6.5g/t gold and 15g/t silver canbe obtained, the recovery of copper,gold and silver are 85.95%,74.55% and 52.95% respectively. The cobalt sulfide concentrate with the grade of sulfur and cobalt are 33.28% and 0.259%,which the recovery are 54.81% and 42.66% respectively.LIMS concentrate with iron content 62.73% and recovery of 41.85%,which sulfur content canbe reduced to 0.113%,is also obtained in the closed-circuit.The concentrate with iron content 40.04% and recovery of 35.05% canbe obtained by HIMS,which the ignition loss iron content canbe reached to 54.71%.