Abstract: Process for the treatment of dust- and oxygen-containing exhaust gases which contain sulfur oxides and nitrogen oxides which comprises treating said gases in a reactor at temperatures in the range of 200° to 500° C. and in the presence of a catalyst having free opening surfaces of more than 50% and passages with a hydraulic diameter of more than 2 mm and one or more substances selected from the group consisting of free oxides, carbonates, hydroxides of calcium, magnesium, sodium and potassium and at a Froude number in the range of 1 to 100.

Abstract: Roasting of ores with metal values such as precious metal ores for recovery of metal values with conversion of arsenic to an insoluble form in-situ in presence of an additive such as iron and in presence of oxygen injected initially or supplementally in a roaster such as in a circulating fluid bed roaster; volatilized arsenic in roasting of ores may also be converted to an insoluble form in gas phase in a two stage roaster process after removal of solids from a gas phase and contact with an additive at high oxygen concentration in a second stage roaster.

Abstract: Refractory gold ores are roasted in the presence of added fuels in an oxidizing atmosphere in a fluidized bed at a temperature from 450 to 650° C., which is supplied with oxygen-containing gases; to achieve a low ignition and thus low roasting temperature, sulfur, pyrite or mixtures thereof are used as added fuels.

Abstract: A method for regulating or controlling the content of NOx in the exhaust gases of a glass-melting furnace having several burners operated in alternation, wherein both the beginning and the end of a combustion break (FP+, FP−) are supplied to a binary signal generator (8) which passes a signal to a regulator (4) with a time delay and upon receipt of the time-regulator (4), and the amount of NH3 supplied to the denitrating plant is adjusted to a lower constant fixed value F1 via a control, and by means of a memory element (7) a higher constant fixed value F2 is calculated as amount of NH3 and supplied to the regulator (4), whereupon as soon as the regulator (4) has received the signal of the time-delayed end of a combustion break, the fixed value F1 is adjusted to the fixed value F2 via a control, and subsequently the regulation is directly continued.

Abstract: Organic and/or inorganic substances and water are thermally separated from contaminated materials, solid aggregates, the contaminated material is pretreated and is subsequently heated in a directly or indirectly heated furnace, which includes a rotary kiln, a fluidized bed furnace or a floating zone reactor, and during the heating the material is treated with recycled hot gases or recycled hot steam and with oxidizing agents. The exiting processing gases, which contain water vapor, are dedusted, and 80 to 90% by volume of the water vapor-containing processing gases are recycled to the furnace to act as entraining gas. The remaining water vapor-containing processing gases are condensed, the resulting liquid phase is withdrawn, and pollutants are removed from the withdrawn liquid phase by a wet chemical or physical processing.

Abstract: The starting material is a vanadium-containing residue, which contains at least 5 weight percent carbon on an anhydrous basis. The residue is thermally treated in a furnace a) at temperatures from 400.degree. to 700.degree. C. under an oxidizing atmosphere and an O.sub.2 partial pressure of at least 10.sup.-4 bar, measured within the region which is occupied by the residue, and/or b) at temperatures from 500.degree. to 1300.degree. C. under an O.sub.2 partial pressure not in excess of 10.sup.-2 bar, measured within the region which is occupied by the residue. A solids mixture which contains at least 5 weight percent vanadium oxide is withdrawn from the furnace. A multiple-hearth furnace or a rotary kiln or a fluidized bed reactor containing a stationary or circulating fluidized bed may be used as a furnace for the thermal treatment.