Abstract: There is disclosed a method for processing heavy-metal-containing residues from the chemical industry. For an economical and at the same time ecologically safe processing of the heavy-metal-containing residues, the heavy-metal-containing residues are introduced into a primary-gas reaction zone of a shaft gasifier containing at least one solid bed of carbon-containing material. Slag-forming substances are introduced together with the charge substances and/or together with the solid-bed formers to absorb and set the heavy metals. The lower zone of the solid bed is maintained at a temperature above the slag and ash melting temperatures. The viscosity of the slag is less than 100 poise.

Abstract: Exhaust gases containing residual nitric oxide constituents from a processing operation are maintained at an elevated pressure, heated to from 260.degree. C. to 340.degree. C. in a separate heat exchanger, and subjected to multi-stage catalytic reduction with ammonia to produce purified exhaust gases. The pressure of the thus purified exhaust gases is then relieved in an expansion turbine.

Abstract: Exhaust gases containing residual nitric oxide constituents from a processing operation are maintained at an elevated pressure, heated to from 260.degree. to 340.degree. C., and subjected to catalytic reduction with ammonia to produce purified exhaust gases. The pressure of the thus purified exhaust gases is then relieved in an expansion turbine.

Abstract: Waste gas, for example exhaust gas from an adipic acid production process, containing nitrogen oxides and a high proportion of oxygen and/or oxygen compounds is treated to remove the nitrogen oxides by reducing the nitrogen oxides with ammonia at an elevated temperature in the presence of a catalyst comprising an iron oxide and a chromium oxide.