Method of obtaining titanium tanning agent and its application for tanning hides, pelts and fur skins

A method of tanning delimed and pickled, or delimed pickled and chromed pelt using ammonium titanyl double sulfate monohydrate as the tanning agent, wherein said tanning agent is taken in an amount of from 5 to 10 per cent of the pelt weight as referred to the percentage of TiO.sub.2 and wherein said tanning agent is prepared by dissolving titanium-containing material in sulfuric acid to form a solution containing titanium ions;

• adding ammonium sulfate to said solution in an amount of 180 to 300 g/l and adjusting the content of H.sub.2 SO.sub.4 to 300 to 450 g/l while keeping the aggregate concentration of ammonium sulfate and H.sub.2 SO.sub.4 to from 520 to 620 g/l in order to precipitate substantially all the titanium from said solution as ammonium titanyl double sulfate monohydrate at a temperature of 12.degree. to 30.degree.C.;
• removing said precipitate;
• washing said precipitate with a solution containing 300 to 450 g/l H.sub.2 SO.sub.4 and 180 to 300 g/l of (NH.sub.4).sub.2 SO.sub.4 ;
• and then washing the precipitate with a solution containing 300 to 400 g/l of ammonium sulfate.

A method of tanning delimed skins wherein delimed skins are treated with dichromic acid and then with ammonium titanyl double sulfate monohydrate as the tanning agent in an amount of from 2 to 4 per cent by weight of said skins with a subsequent reduction of chromium to the trivalent form and wherein said tanning agent is prepared by dissolving titanium-containing material in sulfuric acid to form a solution containing titanium ions;

• adding ammonium sulfate to said solution in an amount of 180 to 300 g/l and adjusting the content of H.sub.2 SO.sub.4 to 300 to 450 g/l while keeping the aggregate concentration of ammonium sulfate and H.sub.2 SO.sub.4 to from 520 to 620 g/l in order to precipitate substantially all the titanium from said solution as ammonium titanyl double sulfate monohydrate at a temperature of 12.degree. to 30.degree.C.;
• removing said precipitate;
• washing said precipitate with a solution containing 300 to 450 g/l H.sub.2 SO.sub.4 and 180 to 300 g/l of (NH.sub.4).sub.2 SO.sub.4 ;
• and then washing the precipitate with a solution containing 300 to 400 g/l of ammonium sulfate.