Abstract: A process for recovering copper from copper sulfide minerals, the method comprising the steps of leaching copper sulfide minerals with an aqueous solution of ammonium chloride containing cupric chloride at a temperature of between about 40° C. and about 95° C. at atmospheric pressure, to produce a solution of cuprous/cupric chloride.

Abstract: A method for purifying heavy metal impurities (such as antimony, arsenic, iron, cadmium, and lead) from 28 to 38 weight percent aqueous crude sodium sulfate solution is achieved by adding ferric sulfate to the aqueous crude sodium sulfate solution to form a suspension, progressively neutralizing the suspension from a pH of less than 3.5 up to at least 6, and separating the ferric-sulfate-nucleated precipitate from the suspension. An oxidizing agent such as peroxide is optionally added to the suspension to augment adsorption of the heavy metals.