Deutsche Gold- Und Silber-scheideanstalt Vormals Roessler

Degussa Aktiengesellschaft

Leybold-heraeus Gmbh

Degussa Gmbh

Degussa Atiengesellschaft

Deutsch Gold-und Silber-scheideanstalt

Helmut Knorre

Joachim Fischer

Gerhard Pohl

Manfred Langer

Klaus Stutzel

Roy Norcross

Andrew Griffiths

Juergen Loroesch

M Quamrul Ahsan

Friedrich W Merz

Peter Leidl

Gerhard Morlock

Wolfgang Fischer

Heinz Haschke

Stephen Gos

Friedrich Fauser

Willi Fischer

Annette Ziegler

Steven Gos

Axel Waniorek

Mathias Stoll

A process is described for leaching gold and/or silver from ores or ore concentrates using an aqueous alkaline cyanide solution with addition of hydrogen peroxide. The addition of the aqueous H.sub.2 O.sub.2 solution is regulated and controlled through the concentration of the oxygen dissolved in the leaching solution, the leaching solution containing from 2 to 20 mg O.sub.2 and preferably from 7 to 13 mg O.sub.2 per liter. 0.5 to 5% by weight H.sub.2 O.sub.2 solutions are preferably added. The process is applicable both to leaching by agitation and to heap leaching, the addition of H.sub.2 O.sub.2 being regulated and controlled through measurement of the O.sub.2 concentration in the leaching solution and can also involve measurement in a measuring stream. Despite low consumptions of H.sub.2 O.sub.2 and NaCN, the gold yield is even increased in some cases and the leaching time shortened.

Process for the leaching of gold and silver with cyanidic leaching

A process for leaching gold and silver from ores and ore concentrates is disclosed using a cyanide leaching solution and hydrogen peroxide and maintaining an oxygen concentration of 2 to 20 Mg of O.sub.2 /liter. In the invention, leaching takes place in the presence of decomposition catalysts and preferably the formed cyano-complexes are separated during leaching from the leach solution. Decomposition catalysts are manganese compounds, present as 0.01 to 1 mg computed as Mn/liter of barren solution, or 1 to 50 mg computed as Mn per kg of ore slurry, or they are inorganic or organic polymers or carbon. Activated charcoal is preferred and simultaneously adsorbing cyano-complexes of precious metals. The process offers lowered consumption of H.sub.2 O.sub.2 and possibly cyanide and maximum gold yield in a shortened leaching time.

Process for leaching precious metals with hydrogen-peroxide and a

This invention pertains to a method of treating cyanide contained in wastewater with particularly high levels of solids in the stream. The process involves either simultaneous or step-wise dosage of hydrogen peroxide in the form of an aqueous solution of a concentration between 35% to 90% by weight, preferably at least 50% by weight, and SO.sub.2 either in the form of gaseous SO.sub.2 or solution of sodium and/or potassium sulfite or metabisulfite resulting in the conversion of cyanide ions to non-toxic cyanate ions.

Cost effective process for detoxification of cyanide-containing effluents

Treatment of effluent containing cayanide is disclosed wherein a mixture of H.sub.2 SO.sub.4 and H.sub.2 O.sub.2 with between 0.01 and 0.5 moles of H.sub.2 SO.sub.4 per mole of H.sub.2 O.sub.2 is used.

Process for the treatment of effluents containing cyanide and other

In purifying gas wash waters containing cyanide with formaldehyde, the exact dosing of formaldehyde presents a problem, especially with strongly fluctuating cyanide contents. By continuous potentiometric measurement in a side stream which is regulated to a pH of 7 to 10, while the pH of the main stream remains unchanged, the formaldehyde can be adjusted safely to any cyanide content.

Process for the purification of industrial gases or waste gases

There is provided a continuous process for the lowering of the content of toxic materials in waste waters which also contain other oxidizable materials by quickly and continuously ascertaining the requirement of hydrogen peroxide, namely by potentiometric determination of the oxidizing agent requirement in a branched-off side-stream using a strong oxidizing agent, such as peroxymonosulfate, peroxydisulfate, permanganate, hypochlorite or ozone, which acts more quickly than hydrogen peroxide under comparable conditions.

Process for the treatment of continuous waste water streams having

The object of the invention is a process for recycling used lubricating oils. After drying and gasoline removal, the oil is distilled and then treated with sodium or sodium hydride in a finely-divided state at elevated temperature. This is followed by a further distillation. Both distillations are at temperatures below 300.degree. C., the oil fractions of low volatility being respectively distilled in a molecular distillation apparatus at below 2 mbar.

Process for recycling of used lubricating oils

In the detoxification of waste waters containing nitrite ions by means of hydrogen peroxide the addition of hydrogen peroxide is automatically controllable by adding the hydrogen peroxide continuously or in portions with continuous measurement of the pH and stopping the addition when no further reduction of the pH is caused by it. By control of the hydrogen peroxide addition through the change of the pH it is guaranteed that sufficient hydrogen peroxide is added to reach a complete detoxification of the waste water while on the other hand there is not wasted hydrogen peroxide unnecessarily.

Process for automatically controlling the detoxification of waste waters

A method for reprocessing used lubricating oils is disclosed wherein the oil is dried, treated with finely dispersed sodium metal at elevated temperature, the remaining free or organically bound metal is decomposed by means of an active hydrogen containing compounds, followed by distillation of the oil for recovery.

Procedure for the reprocessing of used lubricating oils

A process for the reprocessing of used lubricating oil wherein said oils are treated with a mixture of potassium hydroxide and sodium hydroxide.

Process for the reprocessing of used lubricating oils (II)

Copper (Cu.sup.++)-ions are separated from an effluent containing complexing agents which are ethylenediamine tetraacetic acid and/or diethylenetriamine pentaacetic acid or their anionic salts, by using an HS-containing triazine compound and Fe.sup.+++ -ions in a quantity at least equal to the amount of complexing agent.

Process for the separation of Cu.sup.++ -ions from sewage, waste water

Cadmium (Cd.sup.++) ions are separated from an effluent containing complexing agent such as nitrilotriacetic acid, ethylenediamine tetraacetic acid and/or diethylenetriamine pentaacetic acid, or their anionic salts by using an HS-containing triazine compound and Fe.sup.+++ ions in a quantity at least equal to the amount of complexing agent.

Process for the separation of cadmium (Cd.sup.++)-ions from sewage,

There is described a process for the production of inert solvent soluble metal alcoholate free from alcohol of crystallization by reacting an alkali metal with an alcohol in an inert solvent above its melting point in an emulsion of the alkali metal in a solvent.

Process for the production of crystalline alcohol free alkali metal

The use of a container in a metallurgical process, said container comprising two or more components which are clinched or crimped together, said container having contents which comprise an air, moisture, or air and moisture sensitive material, said use comprising introducing said container with its contents into a melt comprising at least one metal. The combination of the container and additive and an improved metallurgical process are also provided.

Packages for the storage of air and moisture sensitive metallurgical

Gypsum plaster having a delayed setting time is made by adding a mixture of mesotartaric acid and l-tartaric acid or d,l-tartaric acid or a mixture of l-tartaric acid and d,l-tartaric acid to the gypsum plaster.

Growing community of inventors

Seligenstadt, Germany

Helmut Knorre