DE878638C - Manufacture of titanium dioxide - Google Patents

Description

Manufacture of titanium dioxide There are very many processes that titanium dioxide is produced Manufacture from titanium and iron ores. In these procedures, the Substances subjected to a decomposition process, which is a water-soluble compound of titanium supplies and then this water-soluble compound mostly hydrolytically split and separated from the accompanying substances during this hydrolysis. at all these processes require very difficult digestion and washing operations, to get to '110 pigments.

It has now been found that Ti0. can be obtained very easily from titanium and iron-containing substances if the reduced iron is heated to the melting temperature of the mixture with the addition of reducing substances and alkaline earth oxides or compounds providing alkaline earth oxide in the heat or, 'and alkali oxides or compounds providing alkali oxide in the heat and separating the titanium-containing slag from one another in the melt flow, extracting the alkali-containing titanium slag with acids and subjecting the extracted slag to annealing. According to this new process, it is thus possible to obtain valuable titanium pigments which are of very high quality with regard to their Ti O. content, without any significant consumption of acids. If you apply to this process z. If, for example, ilmenite is used, pigments are obtained which have a Ti 0 content of about 90%. Any remaining traces of iron that may be present can easily be distilled off by treatment with chlorine. In the latter case, annealing of the extracted slag is no longer necessary.

Example 100 kg of ilmenite, 20 kg of coal and 10 kg of caustic soda intimately mixed, pressed in a briquetting machine in briquette form and in one Rotary furnace heated to a temperature of 300 °. After melting has taken place, the Iron in liquid form is separated from the liquid slag. The obtained slag After cooling, it is heated with dilute hydrochloric acid and filtered off. The residue is now annealed at 8oo to .goo °. The titanic acid obtained is practically iron-free and can be used as a pigment. She has a Ti 02 salary of go ° / o.

. EXAMPLE 2 100 kg of ilmenite, 20 kg of coal and 10 kg of caustic soda are intimately mixed, pressed into briquette form in a briquetting machine and heated to a temperature of 300 ° in a rotary kiln. After melting, the iron is separated from the liquid slag in liquid form. After cooling, the slag obtained is heated with dilute sulfuric acid and filtered off. The residue is calcined in a stream of chlorine at goo ° and freed from the last traces of iron. The titanic acid obtained is pure white and can be used as a pigment.

Claims (2)

PATENT CLAIMS: i. Process for the production of titanium dioxide from titanium and iron-containing substances, characterized by the combination of the following process steps known per se: reduction of iron and titanium-containing substances with the addition of alkaline earth oxide or alkali oxide or alkaline earth oxide or alkali oxide-providing compounds, separation of the iron and the titanium-containing ones Slag from each other in the melt flow, drawing out the slag with acid and afterglowing the leaching residue. 2. The method according to claim i, characterized in that the leach residue to remove the last traces of iron in the presence of chlorine preferably is annealed at 8oo to goo °.