FIELD: chemistry.
SUBSTANCE: present invention pertains to methods of detoxicating toxic wastes and can be used for detoxicating spent solutions from oxidation of steel and cast iron, containing sodium nitrite, nitrate and hydroxide. The method involves adding aluminium metal to the spend solution, in form of wastes - aluminium and aluminium alloy cutting wastes, conversion of nitrite and nitrate into ammonia, and removal of ammonia from the neutralised solution. The first product of the reaction - ammonia - is removed from the solution through distillation at 60-125°C temperature. Optimum temperature of the solution is maintained using heat from reaction of sodium nitrite, nitrate and hydroxide with aluminium cutting wastes. The second product of the reaction is a sodium hexahydroxoaluminate solution, which can be used as a reagent and a coagulant for waste water treatment.
EFFECT: removal of toxic nitrites and nitrates from spent solution from steel oxidation, and reduces material inputs on neutralisation of toxic wastes.
5 cl, 3 ex
