Abstract: In order to manufacture a light, open-pored, mineral insulating board with a gross density below 130 kg/m.sup.3 the following steps are employed:a) producing a water-solids suspension by intensive mixing of the following raw materials in an intensive mixer with a rotating mix container and a mixer mechanism rotating at a higher speed, using water and, in each case referred to the total content of solids, 40 to 48 M % (mass percent) quartz flour with a specific surface area according to BET of at least 2.5 m.sup.2 /g, 15 to 20 M % slaked lime with a specific surface area of at least 15 m.sup.2 /g, 25 to 35 M % cement, 0.3 to 0.5 M % hydrophobic medium, the rest additives, wherein the ratio of cement to slaked lime amounts to 1.5 to 2.3:1, the binder proportion lies in the range from 45 to 52 M % and the suspension has a water/solids factor (without foam) from 0.7 to 1.2,b) preparing a foam from water, air and a pore former, with a gross density from 40 to 50 kg/m.sup.

Abstract: The apparatus for removing the waste layer arising in cutting porous concrete blocks comprises a beam (1) which extends above the porous concrete block in its longitudinal direction and can be raised and lowered, and at least two horizontal support frames (2, 2') mounted thereon and movable in height, which are arranged in pairs opposite one another to the two sides of a vertical central plane (M) of the beam (1) and beneath the same. A plurality of spikes (5, 5') which can be stuck into the waste layer are provided on the underside of each support frame (2, 2') and are aligned with their points facing down at an angle. All spikes (5) of the first support frame (2) of each frame pair (P) are parallel to one another and inclined at an acute angle (.mu.) to the longitudinal central plane (M) and all spikes (5') of the opposite second support frame (2') are parallel to one another and inclined at an opposite acute angle (.mu.l) to the longitudinal central plane (M).

Abstract: A method of autoclaving porous piece-goods, by steam under pressure, wherein the autoclaving operation includes sequential phases of heating with steam, holding, and then relaxing the pressure and temperature, wherein the holding phase includes a drying process. In order to obtain as dry a product as possible with the smallest possible energy input, it is provided that a drying process is carried out within the holding phase in which the autoclave is heated more than to compensate for heat losses and to a temperature above the temperature of vaporization of the water so that the material is dried by controlled discharge of steam from the interior of the autoclave. The steam discharged from one or more autoclaves during the drying process is used to heat up at least partially an autoclave to be heated.

Abstract: An autoclave for treating charged materials (6) with vapor under pressure, with a substantially cylindrical inner chamber (2) surrounded by an autoclave casing (1) and with a heating device (8) responsive to a heated heat transfer medium to generate vapor in the inner chamber (2). In order to provide the heating in a way which is favorable structurally and in terms of energy, it is provided that the heating device (8) is arranged within one of the curved side regions of the autoclave casing (1), and consists of at least one flue (10) arranged substantially vertically in the autoclave and a heat exchanger (11) arranged in the lower inflow region of the flue (10) and through which flows a heat transfer medium, so that a convection flow results circulating substantially in the circumferential direction of the casing (1) of the autoclave.