El medio ambiente en la minería

EL MEDIO AMBIENTE EN LA MINERIA 94 - adequately designed off-gas system comprising an efficient primary gas collecting hood arranged above the block opening in the blowing position, coarse dost removal, cooling of gas to max. 400 oC, final dedosting in hot gas electrostatic precipitators, high velocity interconnecting dust work and draft creation. - closed loop control systems permitting to operate the converter With con– stant blowing air volumes and adequate off-gas volumes. - overall control systems interlocking all relevant activities especialIy during tuming the converter into and out of stack which permits to become independent of the skill of the operator. - system permitting to charge siliea, reverts and serap during blowing through the primary hood. - secondary hoods in addition to the primary hoods serving to improve the situation when the converter is out of stack. Thos with a modem system incorporating above features it is possible to aehieve converter off-gas suitable for an acid plant both in respect to S{h-con– centration and residual dust content with mínimum secondary emissions. To reduce the problems in the acid plant due to the batehwise operation orthe copper converter resulting in strongly fluetuating gas volumes and S(ñ-con– centrations it is essential that the operation of the converter plant with several converters operated in parallel is adequately sehedtded to even out the total flow of converter off-gas as far as possible. Energy management and optimization in sulphuric acid plants for the copper industry Modem copper smelter concepts provide for continuous gas flows ofsufficient concentration to permit operation of the related sulphuric aeid plant with a gas-strenght of 10% S{hor above. Sueh an S02-concentration faeilitates the recovery of excess heat in the form of steam, hot gas or hot water in the acid plant. Thus it is possible to ¡nerease considerably the total energy recovery of a modem copper smelter complexo The potential for energy recovery heavily depends on the technieal concept of the smelter and on the chemical composi– tion of the feed materials. The possible energy recovery and the resulting overall energy balance has been investigated for a modem copper smeltinglrefining complex of a capacity of 100.000 tpy refined copper. The smelter is based on Outokumpu flash smelt– ing, operated with a suitable degree of oxygen enrichment.produeing a high grade matte. One matte converting altemative i.e. PS converter with discon– tinuous off-gas flow and fluctuating S02-concentrations representing todays