Abstract: A method is provided for reducing the consumption of alkaline pH modifier in a mineral separation circuit which employs sulfoxy radical-containing reagents. The method comprises the addition of a non-oxidizing gas to the mineral separation circuit prior to and/or simultaneously with the addition of the sulfoxy radical-containing reagent. The non-oxidizing gas is added in a quantity sufficient to achieve a chemical environment conducive to the flotation separation of minerals. The inventive process is suitable for a wide range of valuable minerals including sulfidic copper minerals or mixtures of sulfidic and non-sulfidic copper minerals, sulfidic iron minerals (particularly pyrite) and non-sulfidic gangue material. It is particularly suitable for sedimentary copper deposits, copper skarns, porphyry copper/molybdenum/gold deposits and super gene enrichments.

Abstract: The present invention provides a process for the recovery of base metal sulfides including chalcocite, chalcopyrite, pentlandite and platinum group metal bearing mineral ores. The process involves passing a slurry of the ore through a reagent conditioning stage wherein suitable activators, collectors, frothers and/or depressants are added, further conditioning the slurry with a non-oxidizing gas in a quantity conducive to the separation of the sulfide minerals from the remainder of the ore and subsequently subjecting the slurry to a final flotation treatment with a flotation gas having a higher oxygen content than the non-oxidizing gas. The non-oxidizing gas conditioning can be carried out prior to or after the reagent conditioning stage.

Abstract: A method for reducing both reagent consumption and scale formation in a mineral separation circuit employing sulfoxy compounds as reagents. The method involves introducing into the mineral separation circuit a non-oxidizing gas in a quantity sufficient to reduce the degree of oxidation of the sulfoxy radical. Preferably the gas is introduced during the reagent conditioning and flotation stages, the stages where the presence of dissolved oxygen in a slurry is most likely to create the conditions conducive to oxidation of the sulfoxy radicals which result in reagent consumption and scale formation problems. The process is suitable for a wide range of mineral separation circuits which use sulfoxy reagents for the separation of sulfidic minerals including chalcopyrite, pentlandite, pyrite, sphalerite, pyrrhotite or galena.

Abstract: A process for the separation of minerals of different mineralogical character. The process involves conditioning a milled slurry or a slurry of a flotation concentrate which contains a mixture of valuable sulfidic minerals and non-sulfidic gangue material with an inert/non-oxidizing gas and/or a reducing/deoxifying agent. The conditioning is conducted to achieve a controlled dissolved oxygen content or electrochemical reduction potential conducive to the separation of the valuable sulfidic mineral, non-sulfidic gangue material. The inert/non-oxidizing gas and/or reducing/deoxifying agent may be added to the slurry in a quantity sufficient to increase rejection of the non-sulfidic gangue minerals or to improve the selectivity between the valuable sulfidic minerals and non-sulfidic gangue minerals.

Abstract: A method of increasing both flotation selectivity and effectiveness of a sulfoxy radical-containing reagent added to a mineral separation circuit. The method involves adding a non-oxidizing gas to the mineral separation circuit prior to and/or simultaneously with the addition of the sulfoxy radical-containing reagent in a quantity sufficient to achieve a chemical environment conducive to flotation separation of minerals. The process is suitable for use with a broad range of slurries and flotation concentrates having a mixture of valuable materials including sulfidic copper minerals, sulfidic and non-sulfidic copper minerals, valuable lead and/or zinc and/or nickel minerals, sulfidic iron minerals (particularly pyrite) and non-sulfidic gangue material. It is particularly suitable for polymetallic ores containing economic values of copper and/or lead and/or zinc and/or nickel which is frequently in association with iron sulfide.

Abstract: A process for recovery of a precious metals containing mineral from a non-sulphidic gangue mineral comprising:preparing a pulp of a material containing the precious metals containing and gangue minerals;conditioning the pulp with an oxidizing gas containing a gas selected from oxygen and ozone; andsubjecting the conditioned pulp to a flotation operation for recovery of the precious metals containing mineral.

Abstract: An apparatus for dispersing a gas into a fluid stream. The apparatus has a generally annular body disposed to define an orifice in the fluid stream, a plurality of inwardly depending apertures formed in the body and in fluid communication with a supply of pressurized gas. Each of the apertures defines a localized injection point for dispersion of the pressurized gas into the fluid stream. The orifice includes a restricted throat section adapted to progressively reduce the effective cross-sectional flow area of the fluid downstream of the apertures, such that resultant velocity and pressure differentials enhance dissolution of the gas in the fluid.

Abstract: A process for recovering a secondary base metal mineral from a material containing it involving treatment of a pulp of the material with surface modifying reagent such as a water soluble sulphide. The pulp is subjected to deaeration by introduction of a non-oxidising gas to prevent oxidation of the reagent. The process is applicable to recovery of secondary minerals such as azurite, malachite, cerussite, anglesite and zinc ferrites from host materials.

Abstract: A flotation process for the separation of a mineral of non-sulphidic character, such as a talcose mineral, from a mineral of sulphidic character, for example a base metal sulphide, characterized in that a slurry containing a mixture of the minerals is subjected to a sequence of mineral dressing operations in which a non-oxidizing gas or gas mixture and a reducing agent are added to the slurry to maintain an electrochemical potential conducive to the separation of the minerals by flotation.