FIELD: separation.
SUBSTANCE: invention relates to sulphuric-alkaline waste purification units. Proposed are two variants of the unit including two carbonisation columns, an oxidising reactor with a cooling unit, an apparatus with a submerged burner, a recuperative heat exchanger, three refrigerators and a separation apparatus. During operation of the unit according to the first variant, sulphuric-alkaline wastewater is supplied to the first carbonisation column wherein light sulphuric compounds are blown off by a part of the flue gas supplied from the apparatus with a submerged burner. The produced sulphur dioxide together with the exhaust air and fuel are supplied to the burner. Carbonised wastewater is removed from the first carbonisation column, heated in the recuperative heat exchanger, and sent together with air to the bottom of the reactor wherein sulphuric compounds are oxidised in the presence of a heterogeneous catalyst. The oxidised wastewater is removed from the top of the reactor, cooled in the first refrigerator and separated in the separation apparatus into exhaust air and oxidised wastewater supplied to the apparatus with a submerged burner wherefrom the heated oxidised wastewater is removed, cooled in the recuperative heat exchanger, mixed with a circulating cooling agent after the cooling unit, cooled in the second refrigerator and supplied to the upper part of the second carbonisation column into the lower part whereof the remaining flue gas is supplied after being cooled in the third refrigerator. Exhaust gas is removed from the top and purified wastewater is removed from the bottom of the second carbonisation column, wherein some of the wastewater is supplied to the cooling unit as a circulating cooling agent. Operation of the unit according to the second variant is characterised by sulphur dioxide and air being supplied to the burner.
EFFECT: technical result is nonchemical and waste-free purification of sulphuric-alkaline wastewater.
2 cl, 2 dwg
