Phosphorus compound recovery from incineration residues of sludge, animal or other bio-wastes involves dissolution of the phosphates in diluted mineral acid and gives by-products useful in building materials

摘要

Recovery of phosphorus compounds especially from incineration residues of sludge and/or animal- with other bio-wastes is effected by a process involving dissolution of the phosphates in diluted mineral acid, followed by separation processes. Recovery of phosphorus compounds from incineration residues (especially ash from complete or partial incineration residues of sludge and/or animal- (with other bio)-wastes involves: (i) applying diluted mineral acid to the residues to dissolve the phosphates; (ii) separating the phosphate-containing solution from the insolubles and from precipitated soluble non-phosphate components; (iii) working-up the phosphate solution according to its proposed use; and (iv) using the separation residues optionally with further work-up e.g. as building materials.