Newmont USA Limited

Newmont Gold Company

Newmont Mining Corporation

Newmont Mining Corporation and Newmont Gold Company

Gopalan Ramadorai

Anthony L Hannaford

Rene R Fernandez

Gurudas Samant

Gebhard Bandel

Bodo Peinemann

Arno Fitting

Hans Kofalck

K Marc Le Vier

K M Le Vier

Roasting of ores with metal values such as precious metal ores for recovery of metal values with conversion of arsenic to an insoluble form in-situ in presence of an additive such as iron and in presence of oxygen injected initially or supplementally in a roaster such as in a circulating fluid bed roaster; volatilized arsenic in roasting of ores may also be converted to an insoluble form in gas phase in a two stage roaster process after removal of solids from a gas phase and contact with an additive at high oxygen concentration in a second stage roaster.

Process for treating ore having recoverable metal values including arsenic containing components

Refractory gold ores are roasted in the presence of added fuels in an oxidizing atmosphere in a fluidized bed at a temperature from 450 to 650&deg; C., which is supplied with oxygen-containing gases; to achieve a low ignition and thus low roasting temperature, sulfur, pyrite or mixtures thereof are used as added fuels.

Recovery of a precious metal value from refractory carbonaceous and sulfidic ores, concentrates or tailings which also include arsenic-containing components is improved by roasting the ore or ore concentrate in an oxygen-enriched gaseous atmosphere having an initial oxygen content from about 25 percent (by volume) to about 65 percent (by volume) while maintaining a reaction temperature of less than about 600 degrees Celsius during the roasting and while maintaining a minimum amount of iron to react with arsenic and for forming ferricarsenate; thereafter recovering a thus-roasted ore as calcine, whereby the calcine is amenable to recovery of precious metal values in it; gold ores are preferred candidate ores.

Process for treating ore having recoverable gold values and including

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Tuscon, AZ, United States of America

Gopalan Ramadorai