METHOD OF PRODUCING MINERAL TANNING AGENT Russian patent published in 2014 - IPC C14C3/04 

FIELD: chemistry.

SUBSTANCE: sulphate titanyl-containing and aluminium-containing salts and ammonium sulphate are mixed. The sulphate titanyl-containing salt used is crystalline titanyl sulphate and the sulphate aluminium-containing salt used is aluminium-ammonium alum or aluminium sulphate. The components are mixed in weight ratio of TiO₂:Al₂O₃:(NH₄)₂SO₄=1:0.02-0.1:1.7-2.5 and then reacted in solid-phase mechanical activation mode while supplying energy at a rate of 2-5 kW-h/kg of the mixture for 15-50 minutes to form a tanning agent. Before reacting the components, water can be added to the mixture in an amount of not more than 3.5 wt % with respect to the weight of the mixture. The disclosed method is characterised by a 5.5 times shorter duration on average and enables to reduce consumption of ammonium sulphate 1.75-2.25 times while avoiding use of sulphuric acid. The obtained composite tanning agent with content of the active titanium component of 17.6-22.7 wt % with respect to TiO₂ has basicity of 40-43.6%.

EFFECT: method is technologically effective and environmentally friendly.

3 cl, 8 ex