New Treatment Process for Three Wastes Generated from Chloride TiO₂ Pigment Production

In view of shortcomings in conventional ’three wastes’ treatment method,a new process is developed to deal with the wastes generated from chloride TiO₂ pigment production.In the process,waste slag from chlorination can be slurried with acid waste water produced from washing off-gas,and then it can be recycled after filter pressing,neutralization and sedimentation,and refiltering.The liquid waste generated from filtration can be directly evaporated and concentrated with high temperature flue gas from burning off-gas containing high CO,and a co-product of calcium chloride dihydrate can be obtained at the same time by desulfurizing the off-gas.The process not only solves the problem that SO₂ concentration in the off-gas exceeds standard,but also creates economic benefits for enterprises through comprehensive treatment.The practical production shows that with this process,waste dust and waste water emissions are greatly reduced compared with the traditional process,and CO,SO₂ and COS difficult to deal with in the off-gas are successfully eliminated or recycled.About 100 kg of raw materials can be recycled and about 250 kg of by-product calcium chloride can be produced per ton TiO₂ product.