Abstract: In producing a copper concentrate by flotation in which copper minerals are separated from arsenic minerals by using oxoacids of sulfur and oxidants, the arsenic in the copper concentrate is reduced by a simple method. In producing the copper concentrate by the flotation in which an arsenic-containing copper ore is a raw material, the oxoacids of sulfur and hydrogen peroxide as the oxidant are used together as additive reagents, and added in this order.

Abstract: The present invention provides a method for producing lithium carbonate, that can shorten the time required in the production of lithium carbonate and has excellent maintenance property and production efficiency without forming fixed matters that require complicated procedures to remove in a reaction apparatus.

Abstract: The present invention provides a method for producing lithium carbonate, that can shorten the time required in the production of lithium carbonate and has excellent maintenance property and production efficiency without forming fixed matters that require complicated procedures to remove in a reaction apparatus.

Abstract: The present invention relates to a method for producing lithium carbonate, which is important as a raw material of a lithium ion battery and the like, from brine resources. More specifically, the invention relates to a method for producing lithium carbonate, in which carbon dioxide gas obtained by calcining limestone is introduced, in the presence of ammonia, into a concentrated brine, which is prepared from a lithium-containing brine as a raw material through an evaporative concentrating step, a desulfurizing step and an electrodialysis step, thereby depositing lithium carbonate crystals, and the crystals thus deposited are recovered through solid-liquid separation.

Abstract: The present invention relates to a method for producing lithium carbonate, the method including: mixing ammonia and carbon dioxide gas (carbonate gas) with an aqueous solution containing lithium chloride to conduct a carbonation reaction; and thereafter, recovering a produced solid by solid-liquid separation, and also relates to a method for producing high purity lithium carbonate.

Abstract: The present invention relates to a method for producing lithium carbonate, which is important as a raw material of a lithium ion battery and the like, from brine resources. More specifically, the invention relates to a method for producing lithium carbonate, in which carbon dioxide gas obtained by calcining limestone is introduced, in the presence of ammonia, into a concentrated brine, which is prepared from a lithium-containing brine as a raw material through an evaporative concentrating step, a desulfurizing step and an electrodialysis step, thereby depositing lithium carbonate crystals, and the crystals thus deposited are recovered through solid-liquid separation.

Abstract: The present invention relates to a method for producing lithium carbonate, the method including: mixing ammonia and carbon dioxide gas (carbonate gas) with an aqueous solution containing lithium chloride to conduct a carbonation reaction; and thereafter, recovering a produced solid by solid-liquid separation, and also relates to a method for producing high purity lithium carbonate.

Abstract: Basic magnesium carbonate comprising a tubular aggregated particle of flaky fine crystals.

Abstract: Basic magnesium carbonate comprising a tubular aggregated particle of flaky fine crystals.

Abstract: To reliably diagnose catalyst degradation in an air fuel ratio control system without being subjected to the influence of engine operating conditions, a front O.sub.2 sensor output VFO and a rear O.sub.2 sensor output VRO are detected on both the upstream and downstream sides of catalytic converter; air fuel ratio feedback correction coefficients .alpha. are determined on the basis of basic feedback control constants P.sub.R,L or i.sub.R,L and correction values PHOS according to rich and lean air fuel ratio conditions; periods T and amplitudes .alpha..sub.R -.alpha..sub.L of the air fuel ratio feedback correction coefficient .alpha.