PROCESS AND FURNACE FOR THE PRODUCTION OF TiO2 PIGMENT ACCORDING TO THE SULFATE PROCESS

摘要

Method for the production of TiO2 pigments by dissolving titanium raw materials with sulfuric acid, producing a metal sulfate-containing titanyl sulfate solution, hydrolysing the titanyl sulfate, separation of the titanium dioxide hydrate from the metal sulfate-containing sulfuric acid by filtration, optional bleaching the titanium dioxide hydrate by reducing treatment in acidic solution, mixing the titanium dioxide hydrate with doping chemicals, and calcining the titanium dioxide hydrate to TiO2 pigment, characterized in that titanium dioxide hydrate is used as a starting material for the TiO2 calcining which has less than 3 kg sulfate ions per t TiO2 after a treatment with alkali hydroxide and washing out the alkali metal sulfate, the filter cake containing the titanium dioxide hydrate and doping chemicals is dried in a solid drier at 100 to 300 DEG C and the dried solid is subsequently calcined in a calcining furnace at temperatures up to 1100 DEG C (solid temperature) to TiO2 pigments and the exhaust is de-dusted, as well as a calcining furnace for the production of TiO2 pigments from dried sulfate-poor or sulfate-free titanium dioxide hydrate in the form of a rotary kiln with a length : diameter ratio in the range of 5 to 10.