Abstract: Sewage sludge from municipal and industrial sewage systems can be incinerated in conjunction with the incineration of refuse in a refuse incinerator as environmentally safely as possible, with a favorable energy balance and low expenditures for technology and equipment. The sewage sludge can be fed into a rotary tubular kiln, while in a countercurrent, flue gas from a refuse incinerator can be passed through the rotary tubular kiln. The resulting vapors from the sewage sludge incineration can then be injected back into the refuse incinerator for afterburning, while the components of the vapors are useful for the reduction of the formation of nitrogen oxide during the incineration of the refuse.

Abstract: Conventional black coatings for objects of common use usually formed as a carbon layer or porous metal layers, have a deficient wear resistance and surface quality. The resistant high gloss black coatings according to the invention comprise oxycarbonitrides, the proportion of carbon. Preferably the layer comprises an oxycarbonitride of an alloy of Ti, Zr and Hf, the oxygen component between 40 and 60 atom percent. Use of the invention is mainly for decorative utility objects, e.g. watch cases.