GB190228256A - An Improved Process and Means for the Treatment of Blast Furnace and other Slags. - Google Patents

Abstract

28,256. Passow, H. Dec. 22. Slags, treatment of; cements. - Relates to the treatment of blast-furnace or other slags for the production of granulated or pulverized slags, which are chemically and physically suitable for the production of cements as described in Specifications No. 14,278, A.D. 1900, No. 13,793, A.D. 1901, and No. 18,953, A.D. 1902. The granulated slag is made in a chemically-active form in relation to carbonic acid, or in a chemically-inert form, or both kinds may be produced at the same time by regulating all the variable elements of the apparatus. The chemically-inert form is produced by breaking the molten slag into spherules or thin sheets, and cooling it as rapidly as possible below a visible heat without contact with water. The chemically-active form is produced by cooling the granulated slag rapidly to the plastic state, and then more slowly to a point below visible heat ; preferably also the pulverizing should be arranged to produce irregular spongy or blistered particles or masses, and this may be done by admitting some water and air to the acting surface of a revolving apparatus. The nature of the product may be determined by regulating one or more of the following items :-the flow of the slag; the pressure, temperature, &c. of the air, gas, or steam blast in spraying-apparatus ; or the velocity, temperature, &c. of the acting surface in revolving or other mechanical apparatus ; or the height of fall, if the granulation is produced in that way ; the disposition and temperature of the cooling or collecting surfaces ; and the temperature of the air and the distance through which the slag or granulated slag falls or is thrown. As shown in the diagrams, the slag falling from the spout A is granulated by a blast B, Fig. 4, by a revolving disc B, Fig. 2, or by falling through an air current F, Fig. 3, and is caught by collecting-surfaces and conveyers, such as C, D, E, placed in various positions and cooled by water circulation. Adjustments may be made in any one or more parts or stages of the apparatus.