Abstract: The invention relates to a method and apparatus for extracting gold from gold ore. The apparatus and process save capital and operating costs in the extracting of gold from gold ore and include comminution and leaching of the ore, and more particularly the apparatus and process reduce the costs for the ore grinding, and make a fine ore grinding superfluous without having to accept a reduction in the gold yield during leaching. The gold ore is subjected to a product bed stressing and interparticle crushing in the nip of a high-pressure roller press before being leached and the product that has been product-bed-comminuted and subjected to interparticle crushing and the product agglomerates thereby formed are piled on a heap that is sprayed with a lixivium.

Abstract: The invention relates to an apparatus and method for producing a free flowing coal suspension high in solids content. The coal is ground in at least two stages utilizing a mill having a calibrating effect in one stage and a mill without calibrating effect in another stage and adding a sub-quantity of viscosity reducing additive to the coal before each grinding. A drying of the coal or reconcentration of the suspension is not required. A roller mill operating on the principle of materials bed comminution is preferred as the non-calibrating mill in the first grinding stage and a rotating drum mill or a vibration grinding mill with rods as grinding bodies is preferred as the calibrating mill.

Abstract: A method and apparatus for continuous pressure comminution of brittle grinding stock such as cement clinker wherein simultaneous operations of unit grain comminution and product bed comminution are carried out in the roller gap of the same roller machine in such a manner that the grinding stock is first precomminuted by means of the unit grain comminution in a wider roller gap and immediately thereafter, the grinding stock fragments produced in the unit grain comminution are further comminuted by the technique of product bed comminution in the region of the narrowest roller gap. The continuous pressure comminution is characterized by a high pressure of more than 2 metric tons per centimeter of roller length, with a sifter being provided after the pressure roller.

Abstract: A roller crusher for receiving a harder to grind material, means mixing the harder to grind material with an easier to grind material and delivering the mixed materials to a ball mill for common grinding, separating the remaining coarse particles from material received by the grinder by a sieve or a cyclone, and recirculating the remaining the coarse particles to the ball mill.

Abstract: The leaching, precipitation and flotation method of recovering metals from ores is simplified by carrying out the leaching and precipitation steps simultaneously in the same reaction vessel. The method is particularly useful for recovering metals from low grade ores. During the leaching and precipitation step, mechanical comminution of the ore is also effected. The preferred reaction vessel is oscillated and the leaching and precipitation process is continuously effected by passage of the materials through the reaction vessel. The method is particularly suitable for recovering copper from oxygen containing copper ores.

Abstract: Improved method and apparatus for the precipitation of cement copper from a copper solution mixed with pieces of iron. The cement copper depositing on the iron pieces is loosened therefrom by means of constant movement of such pieces and then is separated and collected from the decopperized solution.

Abstract: A reactant gas is mixed intimately with a liquid and/or particulate solution in a pressurized container and agitated with high energy. Mixing occurs initially by spraying the liquid and gas together to form an emulsion with great surface contact between the reactants, and the emulsion mix is improved and maintained by agitating in the container. The container is carried on oscillatable supports and is driven by an imbalance drive for vertical oscillation in any of several configurations. Loose mixing balls or bodies are optionally carried in the container to increase the agitation and to grind solid particles carried into the solution. The grinding bodies also source protective reaction-deposited layers from the solid particles to speed the reaction. Pressure and temperature of the process is readily controlled.