Mineral granules prodn. with improved control of particle size - by continuous casting of fused mineral onto blades of rotating drum and quenching the prod.

摘要

Method of obtaining mineral material in divided form of predetermined granulometry comprises casting the molten material under pressurised jets of water on an inclined plane opt. cooled by spraying in air by the action of a rotating drum with fins or blades. Specifically, the number and positions of the blades are designed to bring about the desired granulometry. Pref. the drum has 2-4 blades arranged at 180-190 deg. on the surface to produce granules or balls contg. at least 40% of grains above 4mm and at least 10% of nodules of average dia. above 10mm. Alternatively the durm carries at least 12 blades regularly distributed over the surface to obtain a material contg. at least 40% of grains of dia. below 1mm and at least 5% granules above 4mm dia. The method is used to granulate molten material such as cements metallurgical slags and scoria, glass, ceramics and refractories, and to mfr. fibres, and hence building products. Thermal and acoustic reinforced insulating panels and concretes can be made. Improved control of particle size ranges is achieved by suitable control of the dimensions of the drum and blades, their number and the rate of rotation of the drum. The fibres are suitable for replacing asbestos.