PRODUCT AND PROCESS FOR PRODUCING CHROME-FREE TANNED LEATHER

摘要

The invention relates to a product for leather tanning and to a process for using the former in tanning bovine and sheep hides. The product according to the invention consists of 8-5% technical grade sulfuric acid, 3-10% unrecyclable metallurgic waste (selected so as to have a composition of min. 95% Ti, min. 95% Zr, max. 5% Al, max. 1% Fe and max. 0.5% V), 10...20% technical grade sodium citrate, 1.0...4.0% technical grade magnesium oxide, having the appearance of a gray-white powder with a content of 8-18% titanium and zirconium metal oxides, a so that the ratio of TiO 2 :ZrO 2 ranges between 1:1 and 3:1 and the pH value of 10% solution is 1.8...2.2 and to a chromium-free bovine and sheep hide tanning process for semi-processed chrome-free wet-white leather, in which said powder tanning product is used.