Protein and chromium recovery from tannery waste - consists of grinding for treatment with milk of lime or sodium hydroxide soln., etc.

摘要

The process comprises grinding, reaction in alkali medium, removal of the chromium in acid medium, and acid washing of the protein. The protein is then dried, with concn. of the chromium soln..S Pref., complete hydrolysis of the protein via a sodium hydroxide soln., etc., for chromium hydroxide pptn. and filtration, can obviate some of the process stages. The pulp with 0.8-2 mm particles, is produced by addition of 10 m3 of water per t of waste, and is e.g. treated 2-6 hours at room temp. on using 7.7 kg of milk of lime (hydrated lime mixed with water) and 3% of calcium hydroxide per 100 kg of pulp.