Abstract: Disclosed is a process for the selective removal of copper compounds, and other impurities with respect to molybdenum and rhenium, from concentrates of molybdenite (MoS2) with a copper content that is higher than 0.5% in dry weight.

Abstract: Disclosed is a method for the removal of arsenic from materials containing a high arsenic content, or materials containing a high content of arsenic and selenium.

Abstract: Disclosed is a process for the selective removal of copper compounds, and other impurities with respect to molybdenum and rhenium, from concentrates of molybdenite (MoS2) with a copper content that is higher than 0.5% in dry weight.

Abstract: Process for the removal of arsenic from materials with a high arsenic content or materials with a high content in arsenic and selenium that comprises: Adding the material to a pressurized reactor; Adding an alkaline lixiviating solution of a strong base dissolved in water to the reactor; Adding an oxidizing gas to the reactor; Mixing the above components in the reactor to obtain a homogenous pulp and subjecting it to a lixiviation under pressure that is selective for arsenic with respect to the other elements of interest present in the treated material; Subjecting the pulp obtained from the lixiviation step to a first solid-liquid separation step, thereby obtaining a liquor with dissolved arsenic and a solid with low arsenic content; Subjecting the liquor with dissolved arsenic to a precipitation of the arsenic with a precipitating agent, selecting compounds that supply the following cations: Ce3+, Fe3+, Mg2+, and a combination of Fe3+ and Ca2+; And, subjecting the product of the arsenic precipitation step