Abstract: A brickmaking press comprises a segmental ring, a brick shaping mold supported by the segmental ring in the mold cavity defined thereby, a clamping ring surrounding and enclosing the segmental ring, and the clamping and segmental rings defining an annular chamber maintained under fluid pressure.

Abstract: In an industrial process of preparing high-purity magnesia from an impure magnesium-containing starting material, wherein the starting material is dissolved in HCl and the resultant acidic solution is subjected to a multistep treatment for precipitating the impurities out of the solution, the precipitate is separated from the residual purified magnesium chloride solution, and the magnesium chloride is thermally decomposed to obtain magnesia, the purified magnesium chloride solution is first concentrated and sulfate ions are then added thereto to precipitate calcium ions from the concentrated solution as calcium sulfate.

Abstract: A control for the amount of a gaseous fluid absorbed in a liquid flowing through an absorption column comprises a gage in an outlet from the absorption column for the liquid having the gaseous fluid absorbed therein, an auxiliary absorption column of a substantially smaller capacity than that of the absorption column and receiving a comparatively small amount of the gaseous fluid in addition to the liquid, another gage in an outlet from the auxiliary absorption column for the liquid having the gaseous fluid absorbed therein, the gages measuring respective parameters which are a function of the amount of the gaseous fluid absorbed in the liquid in the respective outlets and producing output signals corresponding to the respective parameters, a comparator connected to the gages for receiving the output signals and comparing them to produce a control signal, and a flow control in the inlet for the gaseous fluid or the liquid of the absorption column, the flow control being connected to the comparator and control

Abstract: Granulated magnesium hydroxide is prepared by agglomerating finely divided magnesia with water as a binding agent to produce granules, the water serving to hydrate the magnesia. The magnesium hydroxide may be thermally decomposed to obtain magnesia of a large specific surface, such as microporous magnesia.

Abstract: A fired refractory brick composed of magnesia, 2 to 10% alumina, calcium oxide and up to 1.5% silica, the weight ratio of calcium oxide to silica being more than 1.4, and at least 2.2(CaO -1.4 SiO.sub.2)% zirconia, calcium and zirconium forming a calcium zirconate phase in the brick and the content of the calcium zirconate phase being from 0.5 to 8%, all percentages being by weight. This brick is prepared from a mixture of the components by pressing the mixture into the shape of a brick and firing the brick at a temperature of 1600.degree. C to 1800.degree. C until the brick contains the indicated amount of the calcium zirconate phase.

Abstract: An apparatus for building up and repairing a refractory lining of an industrial oven or like hot-running vessel comprises a disc rotatable in a horizontal plane for centrifugally depositing a granular refractory material on a portion of the lining to be built up or repaired. A conduit feeds the material to the disc and a stationary cover is mounted over the outlet opening of the conduit and has outlet ports distributed about its circumference. The ports may be selectively closed.