Abstract: A method of dewatering a subterranean space, especially a mine, comprising artificially tapping a water storage zone or collecting water of imbibition and flooding a refill zone, which is separated from said subterranean space by an impermeable seam, with said water through the use of a subterranean pumping station and at least one refill boring, wherein each refill zone is directly flooded with said water from said subterranean space without said water being raised to the surface and then reintroduced to said refill zone.

Abstract: A carbonaceous waste product, preferably containing 30 to 60% mineral substances, 35 to 55% carbonaceous materials, 5 to 20% water, and having a calorific value of 2,000 to 3,500 k cal/kg is fired to produce thermal energy and a combustion residue. The residue is adjusted, if necessary, by addition of mineral containing additives so that it contains 15 to 50% alumina, 15 to 20% silica and 13 to 45% other oxides (mainly iron oxide, manganese oxide and calcium oxide). Sufficient limestone is added to produce a mixture containing 1.8 to 2.2 moles of calcium oxide per mole of silica and 1.1 to 1.3 moles of calcium oxide per mole of alumina. The mixture is then sintered. The total energy requirements of the sintering step are supplied by the energy generated in the firing step. Useful products such as cement and cast stone can be produced from the sintered product.

Abstract: A low grade aluminum and silicon containing starting material is intimately mixed with limestone and the resultant mixture is fluidized. The fluidized mixture is preheated to a temperature of 700.degree. to 900.degree. C., then held at sintering temperature for 5 to 10 minutes. Aluminum may be recovered by extraction of the sintered powder so produced.

Abstract: A process for the production of aluminum chloride from raw materials such as coal slate or bituminous shale is disclosed. The raw material should preferably have an ash content of at least 30% by weight, and with the aluminum content of the ash being at least 20%, calculated as Al.sub.2 O.sub.3. The raw material is first calcined and then chlorinated with a gaseous stream containing chlorine and carbon monoxide to form the aluminum chloride product.

Abstract: A process for the production of aluminum chloride from raw materials such as coal slate or bituminous shale is disclosed. The raw material should preferably have an ash content of at least 30% by weight, and with the aluminum content of the ash being at least 20%, calculated as Al.sub.2 O.sub.3. The raw material is first calcined and then chlorinated with a gaseous stream containing chlorine and carbon monoxide to form the aluminum chloride product.