Abstract: Aqueous hydrogen peroxide solutions containing (1) an organophosphorus compound selected from the group consisting of alkylidene diphosphonic acids, aminotri(methylenephosphonic acid), ethylenediaminetetra(methylenephosphonic acid), and soluble alkali metal salts of the foregoing acids an (2) and organic hydroxy compound selected from allyl alcohol, methallyl alcohol, phenol, o-chlorophenol, o-nitrophenol, o-aminophenol, p-chlorophenol, p-nitrophenol, p-aminophenol, and mixtures thereof are stable during use over a pH range of about 0.5 to 10 against catalytic decomposition by heavy metal ions and by surfaces of insoluble heavy metal sulfides. The stabilizer combinations of this invention are apparently synergistic and give unexpected hydrogen peroxide stability. The stabilized hydrogen peroxide solutions of the invention are especially useful in hydrometallurgical processes and in mineral separations and purifications.

Abstract: An improvement in the process of leaching metal sulfide minerals with an oxidative leaching solution is obtained by adding to the leaching solution over only a portion of the leaching cycle aqueous hydrogen peroxide in an amount ranging from about 2 to about 25 percent by weight of the quantity of hydrogen peroxide required to bring the metal value of the mineral into solution if hydrogen peroxide were used as the sole oxidizing agent.