Abstract: The copper powder contains at least one substance, which is not soluble in copper, e.g. Al.sub.2 O.sub.3, TiO.sub.2, SiO.sub.2 or B.sub.2 O.sub.3. For the production of this copper powder, a surplus of copper metal granulate is mixed with an ammonium salt and/or ammonium hydroxide, together with a saline solution in an aqueous solution, while a gas containing oxygen is added, and at a pH-value of at least 4. A copper-containing precipitate is produced, which is separated and treated at a temperature in the range from 150.degree. to 500.degree. C. in a reducing atmosphere. During this process, Cu(OH).sub.2 and Cu-oxide are transformed into metallic copper powder, which contains the dispersoid. The dispersoid content of the copper powder is preferably in the range from 0.1 to 5% by weight.

Abstract: A process of producing blue copper hydroxide, wherein copper metal is treated with an ammonium ion-containing aqueous solution with stirring and with a simultaneous introduction of an oxygen-containing gas and the reaction product is separated from the copper metal. A particulate, floatable copper (II) hydroxide is produced in that a material which contains copper metal is treated at a temperature of 0.degree. to 40.degree. with a solution which contains 0.1 to 10 g/l ammonium salt (calculated as NH.sub.4), 0 to 10 g/l ammonium hydroxide (calculated NH.sub.3) and, if desired, 0 to 5 g/l copper (II) salt and the resulting copper (II) hydroxide is separated.

Abstract: Nonferrous metal powder or nonferrous metal powder mixtures are made by reacting a metal compound in an aqueous medium with an aqueous sugar or starch solution with stirring and optionally at an elevated temperature and the precipitated metal powder is separated. The nonferrous metal oxide or hydroxide in a concentration between 20 and 400 g/l (calculated as metal) is treated in the aqueous medium at a pH-value above 3.2 and at a temperature between 20.degree. and 160.degree. C. and the virtually oxide free nonferrous metal powder which is precipitated is separated. Oxides or hydroxides of the metals Cu, Ag, Ni, Co, Sn, Pb, Sb, As, or Bi are used.