Metallgesellschaft Aktiengesellschaft

Basf Aktiengesellschaft

Sud-Chemie Ag

Michael Tacke

Hugo Grimm

Ulrich Heinrich Sander

Karl-Heinz Dorr

Waldemar Weber

Eberhard Stolarski

Walter Pierson

Arend Werner

Karl H Dorr

Heinz Neumann

Bruno Triebskorn

Georg Schmidt

Egon Winkler

Robert Peichl

Walter Beitelschmidt

Helmut Diekmann

Peter Ahrens

The ore which contains gold and at least one of the metals silver, copper, nickel, zinc or iron is calcined at temperatures in the range from 500.degree. to 900.degree. C. with the addition of oxygen-containing gas, thereby producing a metal-oxide-containing solids mixture and a SO.sub.2 -containing exhaust gas. The SO.sub.2 containing exhaust gas is brought in contact with aqueous solution, thereby producing a sulfite-containing solution. The solids mixture from the calcination is cooled to temperatures in the range from 50.degree. to 300.degree. C. and is stirred up with the sulfite-containing solution. Metal oxides are dissolved, and a sulfate-containing solution os formed. In a first separating zone, the sulfate-containing solution is separated from the solids, and either the solids are supplied to a gold leaching or the sulfate-containing solution is subjected to a further treatment for the separation of nonferrous metals.

Process for treating gold-containing sulfide ores

The ore which contains gold and/or silver and as accompanying metal at least iron is calcined at temperatures in the range from 500.degree. to 900.degree. C. with the addition of oxygen-containing gas. There is obtained a metal-oxide-containing solids mixture and a SO.sub.2 -containing exhaust gas. The solids mixture from the calcination is cooled, the temperature being reduced by at least 50.degree. C. The cooled solids mixture is added to a fluidized-bed reactor, and SO.sub.2 -containing exhaust gas is introduced into the fluidized-bed reactor. In the reactor, metal sulfate is produced in the solids mixture, so that at least 10% of the sulfur content are bound in the exhaust gas. Solids mixture containing metal sulfate is withdrawn from the fluidized-bed reactor, is stirred up with an aqueous acid solution, thereby dissolving metal sulfate. The remaining solids are supplied to a recovery of gold and/or silver.

Process for treating sulfide ores containing gold and/or silver and as

To effect a quasi-isothermal catalytic reaction of SO.sub.2 to SO.sub.3, a plurality of consecutive rows of banks of cooling tubes, are provided in the bed of shaped catalyst bodies in a contact reactor in such a manner that the banks of succeeding rows are staggered from the banks of the preceding rows. The distance between the cooling tubes in the banks is so selected that a penetration of entire catalyst bodies into the banks will virtually be prevented. The banks are so designed that the pressure drop of the gas in the banks is approximately the same as the pressure drop in the layer of catalyst between the bank. The distance between the banks is larger than the width of the banks.

Contact reactor for a quasi-isothermal catalytic oxidation of SO.sub.2

A process for the production of sulfuric acid from wet sulfur dioxide containing gases is disclosed. The sulfur dioxide containing gas is initially purified and cooled, then predried with dilute sulfuric acid, finally dried with concentrated sulfuric acid, converted to sulfur trioxide catalytically and, the sulfur trioxide is absorbed in sulfuric acid. Preliminary drying removes more water than needed to maintain the water balance in the following process steps. A portion of the dilute acid from the preliminary drying is concentrated prior to recycle to the preliminary drying step and another portion of the acid from the preliminary dryer is added to the sulfur trioxide absorber to adjust the water balance in the acid circulating between the final dryer and the sulfur trioxide absorber.

Process of producing sulfuric acid

Sulfuric acid is produced from sulfur trioxide-containing humid gases by a process wherein the sulfur trioxide-containing humid gases are directly cooled with aqueous sulfuric acid, sulfuric acid is condensed and the gas is cooled below dew point of the sulfuric acid, and the water not required to form sulfuric acid is discharged as water vapor with the end gases.

Process for producing sulfuric acid

Sulfur compounds oxidizable to form sulfuric acid and organic compounds oxidizable to CO.sub.2 and H.sub.2 O are removed from an exhaust gas of a contact-process plant for producing sulfuric acid by treating the exhaust gas with a scrubbing solution consisting of dilute sulfuric acid and peroxydisulfuric acid. The peroxydisulfuric acid is produced electrolytically from fresh dilute sulfuric acid and the resulting electrolyte is continuously introduced into the scrubbing acid cycle. The exhaust gas is treated in a vertical venturi with uniflow, i.e. codirectional flow of the gas and the scrubbing solution, and the gas is then passed through a horizontal venturi and subsequently upwardly through a packing layer.

Process for the removal of gaseous impurities from the exhaust gases of

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Friedrichsdorf, Germany

Michael Tacke