Abstract: A method for producing colloidal mixtures, especially water-cement mixtures with or without further solid additions, comprising the steps of feeding the material for forming the colloidal mixture into a container, stirring the material fed into the container by a blade stirrer driven by a motor at a circumferential speed at the outer diameter of the blade stirrer of at least 500 and preferably 1,500 meters per minute, continuously measuring the variations in the energy take-up of the motor, and stopping stirring of the material when the continuously observed energy take-up indicates a sudden transition from a fluctuating to a substantially steady course; and an apparatus for carrying out this method.

Abstract: A mixture of fine-particle mineral coal and a fine-particle solid carrier of carbon is stored in a bulk store from which the mixture is withdrawn and continuously blown into a shaft furnace, e.g. a blast furnace. Sufficient carbon carrier is used to loosen the mixture and to prevent it from caking and sticking. A suitable carbon carrier is particulate compost obtained by rotting household refuse or sewage sludge.

Abstract: A process of producing a colloidal mortar suitable for use as a lining of steel conduit pipes, boilers or the like, includes filling a mixer with water while imparting to water a rotary motion by a rotary agitator at a speed of 1500 m/minutes, feeding the mixer with cement while maintaining the rotary motion whereby the mixture forms a funnel-like profile within the mixer and adding to the mixture wet sand of humidity of 5-15% and in proportion of 1 to 2 parts of the cement content to obtain the colloidal mortar. Fiber rovings may be added to the colloidal mortar.