Browsing by Author "Mugica, J. C."
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Item Alternatives for processing metal sulfides without SOX emissions(1999) Allain, E.; Gaballah, I.; Kanari, N.; Malau, K.; Mugica, J. C.; Solozabal, R.; Tecnalia Research & InnovationOne of the major sources of the SOX emissions is the metallurgical processing of metal sulfides of Cu, Ni, Pb, Zn, etc. Although new technologies for metal sulfide smelting decrease these emissions, the generated quantity of sulfur oxides is considered as a serious threat to environment. Moreover, these emissions may be considered as an economic loss of the marketable sulfur. On the other hand, conversion of sulfur oxides to H2SO4 requires its consumption on the production sites as the cost of its transportation and stocking are important. Besides, the current state of the sulfuric acid market and the new regulations make the conversion of SOX to sulfuric acid less attractive. This paper deals with the low temperature treatment of complex sulfide ores 'CSO' or concentrates 'CSC' under neutral, reducing and chlorinating atmospheres or their combination. Treatment of CSC with nitrogen, at temperatures lower than 1000°C, allows the decomposition of the pyritic matrix to pyrrhotite and the volatilization of sulfur and As, Cd, Bi, Hg, Ge, Pb, etc., compounds. Using the same reactor, a reducing atmosphere will lead to the reduction of sphalerite to zinc and to a solid containing Cu°, Fe° and silicoaluminates. Selective dissolution of copper may be done by a hydrometallurgical process. Generated hydrogen sulfide could react with pyrrhotite to form pyrite and hydrogen. A flow - sheet of the suggested process is proposed. Complete chlorination of chalcopyrite concentrate was possible above 300°C. Iron and sulfur chlorides were fully volatilized and recovered by selective successive cooling of the gas phase. The chlorination residue is composed of valuable metals' chlorides. However, such process generates hazardous sulfur chlorides 'SXCly'. A part of sulfur chlorides such as SCl2 can be recycled as a chlorinating agent of metal sulfides. On the other hand, SXCly was either hydrolyzed, leading to the recovery of more than 90 pct of elemental sulfur or reduced by hydrogen, at temperatures lower than 600°C allowing the recovery of up to 90 pct of elemental sulfur. A flow sheet for the chlorination of metal sulfides and the treatment of sulfur chlorides is suggested.Item Recuperacion de metales mediante tecnologia de plasma: Aplicacion a los catalizadores agotados de hidrodesulfuracion(1997-01) Aguirre, P.; Mugica, J. C.; Vieitez, J. A.; Tecnalia Research & InnovationItem Treatment of industrial wastes by plasma technology(1998) Aguirre, P.; Mugica, J. C.; Solozabal, R.; Tecnalia Research & InnovationPlasma arc technology offers many advantages over conventional incinerators for industrial wastes treatment. Such advantages are: heat generation is independent of the chemistry involved; the added gas flow rates are low; plasma systems operate at high energy densities; and the atmosphere in the furnace can be selected. Two different plasma equipments are used to treat industrial wastes. The first equipment is orientated to the realization of laboratory scale trials and offers great versatility. The second equipment is orientated to perform pilot scale trials and allows continuous operation, and apart from the plasma reactor, a postcombustion chamber, a quenching and an scrubber are installed in the plasma pilot plant.Item Valuable metals recovery from spent catalysts by selective chlorination(1994-04) Gaballah, I.; Djona, M.; Mugica, J. C.; Solozobal, R.; Tecnalia Research & InnovationThe food, chemical, petroleum, petrochemical and other industries generate thousands of tons per year of spent catalysts containing up to 35% valuable metals such as Co, Cr, Cu, Ni, Mo, Ti, V, W. The recycling of these materials will lead to provision of significant quantities which are currently imported from outside the EC countries and could contribute to the improvement of the environment. Selective chlorination of these spent catalysts with different chlorinating gas mixtures between 300 and 600°C is investigated for the recovery of their valuable elements. Depending on the experimental conditions, it is possible to recover up to 98% of the Ni and Co, as chlorides from the chlorination residue and about 98% of the Mo, Ti & W and 80% of vanadium compounds in the condensates. The catalyst support chlorination could be limited to less than 5%. Besides the reaction temperature and time, the oxygen partial pressure in the chlorinating gas mixture is a key factor for the selectivity of the chlorination.