GB510320A - Process for the granulation of metals, alloys and other fusible materials - Google Patents

Abstract

510,320. Granulating materials. DEUTSCHE GOLD - UND SILBER - SCHEIDEANSTALT VORM. ROESSLER and TRUTHE. W. Jan. 26, 1938, No. 2548. [Class 82 (ii)] [Also in Group III] A method of comminuting molten materials, e.g., metals, metal alloys, metal compounds or slags by pouring them on to a rotating disc is characterised by subjecting the melt to as rapid a cooling as possible by directing a cooling agent as near as possible to the point of impingement of the melt upon the rotating disc, preferably directly on to the said point of impingement, so that the particles are quenched immediately after their formation. The cooling agent may be a stream of gas that serves to prevent too rapid a contact with the surrounding walls, which may be cooled, and the particles may be collected in various fractions in collecting chambers by the method of wind sifting. Examples of gas are nitrogen, carbon dioxide, hydrogen, producer gas, lighting gas or flue gas. Cooling liquids may also be used or cooling liquid and cooling gas may be used together. In certain kinds of melt, e.g., sodium, magnesium, or iron, inert cooling materials, e.g., benzol may be used, and the comminution may take place in an inert atmosphere. The cooling materials may react chemically with the melt. Gases such as oxygen, chlorine, or ammonia, or steam, mixed if desired with inert gas, can be used, and compounds such as oxide of iron or hydroxide of aluminium or zinc chloride or sodium amide can be produced. The reactionable gases, e.g., air, oxygen, steam, sulphurous acid, chlorine, ammonia, hydrogen, carbon dioxide, methane, producer and natural gas or a gas-steam mixture may take the form of an atmosphere in the comminuting chamber. Solid powdered substances such as coal dust, soot, salts, e.g., alkali chlorides may be introduced into the cooling gases and may also be introduced into the melt; or may be mixed with the comminuted material, e.g., metallurgical intermediary product, and the material further worked up. Sulphur or sulphur-containing substances such as sulphides may be introduced before or after comminution of the melt, preferably in quantities 3-10 per cent. The comminuted materials, e.g., oxides, may be collected in liquids to form compounds, e.g., salts. By the use of cooling liquids such as water, or neutral or acid or alkaline solutions the comminuted material may be obtained as a solution or suspension or leach. The comminuted material, if desired mixed with metalloids, carbon, silica, boron, oxides, carbides, sulphides, silicides, pumice, glass, porcelain, and phenol formaldehyde resins, can be pressed and sintered to form moulded bodies. In particular the invention is applicable to gold, silver and the noble metals, copper, iron, nickel, lead, aluminium, magnesium, sodium, alloys, lead glazes, sodium hydroxide, tin and zinc chlorides, ammonium nitrate and naphthalene, glazes, mattes and speiss.