Degussa Aktiengesellschaft

Evonik Degussa Gmbh

Degussa Gmbh

Magotteaux International S.a.

Gerhard Arnold

Juergen Meier

Ingo Hamann

Alan Hitchiner

Horst Kruger

Oswald Helmling

Terry Brown

Christopher Greet

Walter Harper

Paul Reynolds

Ursula Schwartzkopff

Ron Choiniere

Sigrid Anspach

Hans Jelitto

Uwe Wagenknecht

Hans-Ulrich Suss

The present invention is directed to methods that can be used in the enrichment of metal sulfide ores in desired minerals in cases where the ores have sulfide-containing gangues. The method involves adding an oxidant to slurries prepared from the ores during, or immediately prior to froth flotation.

Enrichment of metal sulfide ores by oxidant assisted froth flotation

In a method for recovering a copper sulfide concentrate by froth flotation from an ore containing an iron sulfide, wet grinding of the ore with grinding media made of high chromium cast iron alloy having a chromium content of from 10 to 35% by weight is combined with an addition of hydrogen peroxide to the conditioned mineral pulp before or during flotation in order to improve concentrate grade and recovery of copper sulfides.

Method for recovering a copper sulfide concentrate from an ore containing an iron sulfide

Delignification and bleaching of lignocellulosic material is enhanced after the pulp has been treated with peroxomonosulfuric acid.

Process for bleaching and delignification of lignocellulosic materials

A process and an apparatus are described for the production of peroxyacids from concentrated solutions of hydrogen peroxide and an oxyacid. The total amount of concentrated hydrogen peroxide is divided into at least two portions which are added separately in series to the concentrated oxyacid.

Process for the generation of peroxyacids

Delignification and bleaching of lignocellulosic material is enhanced after the pulp has been treated with peroxomonosulfuric acid. The starting pH of the reaction with peroxomonosulfuric acid is between 7 and 11, and the reaction is continued until a final pH of 3 to 5 obtained. Subsequently the pulp is delignified and bleached with peroxide and/or oxygen.

Process for bleaching and delignification of lignocellulosic

A process for the delignification and bleaching of cellulose with oxygen and hydrogen peroxide, in which in a given case the delignification is carried out with oxygen in the presence of MgO, and the cellulose subsequently is bleached simultaneously with hydrogen peroxide and oxygen at a pH&lt;5.

Process for the delignification and acid bleaching of cellulose with

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Ringwood, NJ, United States of America

Gerhard Arnold