Abstract: A method for producing amino acid chelate compounds, characterized in that metal oxides and/or metal carbonates and/or metal sulfates and/or metal chlorides and/or metal hydroxides in solid form are activated mechanically and then the activated metal oxides and/or metal carbonates and/or metal hydroxides and/or metal sulfates and/or metal chlorides are brought together with amino acids in solid form and converted to amino acid chelate compounds in a solid-state reaction.

Abstract: A method for producing amino acid chelate compounds, characterized in that metal oxides and/or metal carbonates and/or metal sulfates and/or metal chlorides and/or metal hydroxides in solid form are activated mechanically and then the activated metal oxides and/or metal carbonates and/or metal hydroxides and/or metal sulfates and/or metal chlorides are brought together with amino acids in solid form and converted to amino acid chelate compounds in a solid-state reaction.

Abstract: Complete dezincing of steel scrap is achieved by the addition of oils, whereupon the dissolution of iron is substantially suppressed through the autogenous inhibition effect of the oils. The steel scrap arising when the dezincing process has been completed is protected against corrosion by the remaining film of oil, the corrosion protection preventing the formation of iron oxide layers and thus blackening of the scrap material. The oil discharged with the dezincing solution can be separated as a pure phase by resorting to flotation in support of the process and can then be reused as an inhibitor.

Abstract: The invention claims a method for the selective acidic dezincing of steel scrap. The selective complete dezincing is achieved by the addition of oils, whereupon the dissolution of iron being substantially suppressed through the autogenous inhibition effect of the oils. The steel scrap arising when the dezincing process has been completed is protected against corrosion by the remaining film of oil, said corrosion protection preventing the formation of iron oxide layers and thus blackening of the scrap material. The oil discharged with the dezincing solution can be separated as a pure phase by resorting to flotation in support of the process and can then be reused as inhibitor.

Abstract: In order to recover in an environmentally sound and economic manner used hardening shop salts which contain nitrate-nitrite, the salts, comminuted to particle sizes of from 1 to 50 mm, are dissolved in a mixture of nitric acid and hydrogen peroxide without nitrogen oxides arising, and, by evaporation and cooling, potassium nitrate, sodium chloride, and sodium nitrate are obtained sequentially by fractional crystallization.

Abstract: The process for environmentally acceptable and economical recovery of chloride salts from hardening-shop used salts utilizing the steps of leaching of the used salt, detoxification of the cyanide and selective crystallization of the individual chloride salts. The process is characterized in that all the chloride salts that are present in the hardening-shop used salt are recovered in pure form.

Abstract: An eccentric vibrating mill with at least one grinding container, to which is solidly attached the exciter unit as vibrating drive, and in which for the purposes of improving the grinding properties of conventional vibrating mills according to the present invention there is provision for the grinding container to be excited eccentrically on one side, that is, outside the gravity axis and the mass center of the grinding container, whereby a balancing mass is provided for balancing the eccentric mass and the drive side spring axis lies between the gravity axes of the grinding container and the exciter unit and the exciter unit is operated such that uneven vibrations such as circular, elliptical and linear vibrations are produced.

Abstract: A process for the hydrometallurgical recovery of gold and silver by direct oxidizing sulphuric acid-digestion of arsenopyrite-concentrates (FeAsS.sub.2) containing carbonaceous materials with a silicate gangue, and/or a silicate and pyrite gangue whereby arsenic and iron are fully solubilized and the noble metals are quantitatively enriched in the silicate-residue. The concentrate is subjected to mechano-chemical stress to produce structural deformations before being digested in the presence of oxygen. After decarbonization of the residue, gold and silver can be recovered by cyanide leaching without losses due to adsorption. A bulk process for preparing gold and silver rich concentrates is also disclosed.