Metallgesellschaft Aktiengesellschaft

Newmont USA Limited

Newmont Mining Corporation and Newmont Gold Company

Bodo Peinemann

Gurudas Samant

Gebhard Bandel

Anthony L Hannaford

Gopalan Ramadorai

Rene R Fernandez

Arno Fitting

Hans Kofalck

Walter Koch

K Marc 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.

Refractory gold ores are roasted at temperatures from 500.degree. to 650.degree. C. in an oxidizing atmosphere in a fluidized bed, which is supplied with a carbonaceous additional fuel. To effect a substantially complete combustion of the additional fuel to form CO.sub.2 and H.sub.2 O, methanol is added as a carbonaceous fuel.

Process for roasting refractory gold ores

Growing community of inventors

Frankfurt am Main, Germany

Bodo Peinemann