PCT No. PCT / CH96 / 00252 Sec. 371 Date May 15, 1998 Sec. 102(e) Date May 15, 1998 PCT Filed Jul. 8, 1996 PCT Pub. No. WO97 / 02864 PCT Pub. Date Jan. 30, 1997Mercury-contaminated substances are fed through a shredder to a
loader that loads a rotary tubular
kiln, in which a mercury content is evaporated by a primary burner. A temperature of an unlined
rotary kiln is monitored from an outside at various points over an entire length, by
infrared sensors. The thus acquired data are supplied to a regulating unit that regulates
fuel supply and primary air supply through various control lines. Burned gas is supplied through a duct to a
cyclone separator in which solids are separated and returned to the process. The gaseous substances are fed through a postcombustion chamber of a quench to a
washer in which mercury is removed. The residual gas reaches a
chimney through an active
coal filter. This process is particularly easy to control, economical and allows a particularly low residual mercury content to be reached, for example less than 0.1 ppm, in a residual
combustion product.