Abstract: A system and method for online, essentially instantaneous analyses of ore compositions on a moving belt use laser-induced break-down spectroscopy (LIBS), wherein intensity ratios of emission lines characteristic of specific minerals or ions are calculated on areas of the moving belt, with elevated contents of identifying ions or species being detectable. The ratios are derived from ions present in the sample that differentiate a first substance from a second substance, thus allowing sorting of the samples. The substance may include an ion, an element, or a compound.

Abstract: An improved reverse crago process for beneficiating siliceous phosphate includes the steps of subjecting a siliceous phosphate ore material to amine floatation so as to obtain a prefloat concentrate, and screening the prefloat concentrate so as to separate it into 1) a fine predominantly phosphate fraction without substantial amounts of silica, and 2) a coarse fatty acid floatation feed fraction containing phosphate and substantial silica. The coarse fraction is subjected to fatty acid flotation so as to recover phosphate as a fatty acid flotation concentrate.

Abstract: A method of dewatering mineral-containing sludge by adding to the sludge (a) an aqueous solution or emulsion of acrylamide polymer flocculating agent and (b) a microfiber additive. By using this method, such mineral-containing sludges can be quickly dewatered into a cake having 25-35% solids which can then be further processed to a 60% solids-containing material. The method is particularly suitable for use in methods for treating, recovering, rehabilitating and recycling residue of mining operations. The method also enhances the filtration characteristics of certain mineral residues. With modification, the method is also suitable for dewatering organic sludges. Kaolin clay and red mud from the Bayer process are disclosed among the mineral-containing sludges which may be dewatered in accordance with the process of the invention.

Abstract: A method of dewatering mineral-containing phosphatic clay sludge comprising adding to the sludge (a) an aqueous solution or emulsion of acrylamide polymer flocculating agent and (b) a microfiber additive. By using this method, such mineral-containing sludges can be quickly dewatered into a cake comprising 25-35% solids which can then be further processed to a 60% solids-containing material. The method is particularly suitable for use in methods for treating, recovering, rehabilitating and recycling residue of mining operations. With modification, the method is also suitable for dewatering organic sludges.

Abstract: The present invention relates to the coproduction of a combustible gas stream usable as an energy source, a sulfur-dioxide-containing second gas stream usable as a source of oxidant in the gasification of coal, and a sulfur-dioxide-containing third gas stream usable as a feedstock for the production of sulfuric acid. The process includes heating coal in a coal gasification zone in the presence of an oxygen and sulfur dioxide-containing atmosphere under partial coal gasifying conditions to produce a carbonaceous char and a crude coal gas stream. Sulfur-containing compounds are removed from the coal gas stream and converted to elemental sulfur. The carbonaceous char is combined with gypsum to form a feed mixture. The non-gypsum portion of the feed mixture contains sufficient reducing potential to release substantially all of the sulfur in the gypsum as gaseous compounds of sulfur in a +4 or lower oxidation state.

Abstract: A pelletized mixture of gypsum, carbonaceous material and pyrite is charged to a travelling grate where the charge is heated under suitable conditions to produce a solid sintered material which has a broad spectrum of applications due to its chemical and physical properties and a gaseous effluent containing sulfur dioxide, sulfur or mixtures thereof.

Abstract: A coal fired power plant includes a coal gasification zone where coal is gasified in the presence of an oxidant-lean atmosphere under partial coal gasifying conditions to produce a carbonaceous char and a crude gas stream, an acid separating zone where sulfur-containing compounds are separated from the crude gas stream to produce a combustible gas stream, and a converting zone where the sulfur-containing compounds are converted to elemental sulfur. The combustible gas stream and the carbonaceous char are fed into a boiler which drives a generator to produce electricity; portions of the carbonaceous char product and the combustible gas stream are diverted into a gypsum desulfurization zone. SO.sub.2 -containing flue gas from the boiler is fed into a flue gas desulfurization zone. There, the SO.sub.2 -containing flue gas is contacted with lime and limestone to produce gypsum.

Abstract: The present invention relates to the coproduction of a combustible feed gas stream useable as an energy source and a sulfur-containing second gas stream useable as a feedstock for the production of sulfuric acid. The process includes heating coal in the presence of an oxygen-lean atmosphere under partial coal gasifying conditions to produce a solid carbonaceous char and a crude coal-gas stream. Sulfur-containing compounds are removed from the coal gas stream and converted to solid sulfur-containing materials. The solid sulfur-containing materials are combined with the solid carbonaceous char and gypsum to form a feed mixture. The non-gypsum portion of the feed mixture contains sufficient reducing potential to release substantially all of the sulfur in the gypsum as gaseous compounds of sulfur in a +4 or lower oxidation state. The feed mixture is heated under reducing conditions to produce a sulfur-containing second gas stream and a solid sintered product.