Purification of talc
AssigneeEngelhard Minerals & Chemicals Corporation
InventorFred R. Huege
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Abstract
An arsenic sulfide mineral impurity, such as gersdoffite, is removed from talc by an oxidative leach treatment at a pH below 2.
Claims7
A method for removing an arsenic sulfide impurity from talc which comprises acidifying an aqueous pulp of said impure talc to a pH below 2 with an acid selected from the group consisting of sulfuric and hydrochloric, adding to said pulp an oxidizing agent having an oxidation potential with a greater negative value than -1.0 volts, maintaining the pH of said pulp below 2 until said impurity is dissolved therein, separating the talc from said pulp and washing the resulting purified talc product.
Dependencies are inferred from the claim text.