Process for the production of titanium dioxide pigments
AssigneeBayer Aktiengesellschaft
InventorsEckhard Bayer, Gunter Lailach
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Abstract
A process for the production of TiO.sub.2 pigments by the sulfate process by digestion of titanium-containing raw materials with sulfuric acid, hydrolysis of the titanyl sulfate formed, purification of the hydrolyzate and calcination of the hydrolyzate in rotary kilns, wherein the calcination conditions are regulated through adjustment of the SO.sub.2 content of the waste gases issuing from the rotary kilns used for calcination.
Claims7
In a process for the production of TiO2 pigments by the sulfate process comprising digestion of titanium-containing raw materials with sulfuric acid, hydrolysis of the titanyl sulfate formed, purification of the hydrolyzate and calcination of the purified hydrolyzate in rotary kilns, the improvement comprising measuring the SO.sub.2 -content of the calcination off-gases and adjusting the SO.sub.2 content of the calcination offgases issuing from the rotary kilns used for calcination to a constant value said constant value being from 2 to 3.5 g SO.sub.2 /m.sup.3 or from 4 to 8 g SO.sub.2 /m.sup.3.
Dependencies are inferred from the claim text.