Metallgesellschaft Aktiengesellschaft

Newmont USA Limited

Newmont Mining Corporation and Newmont Gold Company

Gebhard Bandel

Gurudas Samant

Anthony L Hannaford

Bodo Peinemann

Gopalan Ramadorai

Rene R Fernandez

Arno Fitting

Hans Kofalck

Rainer Reimert

Hans Beisswenger

Georg Schaub

Dirk Hankel

K Marc Le Vier

Stephan Becker

Erhard Weilandt

Johann Renner

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.

Organic and/or inorganic substances and water are thermally separated from contaminated materials, solid aggregates, the contaminated material is pretreated and is subsequently heated in a directly or indirectly heated furnace, which includes a rotary kiln, a fluidized bed furnace or a floating zone reactor, and during the heating the material is treated with recycled hot gases or recycled hot steam and with oxidizing agents. The exiting processing gases, which contain water vapor, are dedusted, and 80 to 90% by volume of the water vapor-containing processing gases are recycled to the furnace to act as entraining gas. The remaining water vapor-containing processing gases are condensed, the resulting liquid phase is withdrawn, and pollutants are removed from the withdrawn liquid phase by a wet chemical or physical processing.

Process for thermally separating organic and/or inorganic substances

Granular coal is combusted in a circulating fluidized bed system comprising a combustion chamber, a separator and a recycle line for recycling solids from the separator to the combustion chamber. Gas from carbonization is added to the oxygen-containing combustion gas withdrawn from the combustion chamber and is at least partly combusted in said combustion gas to increase the temperature of the combustion gas to about 850.degree. to 1200.degree. C. The gas from carbonization is produced by the heating of granular coal.

Process of combusting coal in a circulating fluidized bed

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Frankfurt am Main, Germany

Gebhard Bandel