The invention discloses a method for harmless treatment on
arsenic-containing
sludge. The method comprises pre-treatment, first-stage
microwave oxidizing
roasting and second-stage
microwave oxidizing
roasting. Concretely, the method comprises carrying out
dehydration on
arsenic-containing
sludge until
water content is in a range of 60-70%, adding a curing agent into the
arsenic-containing
sludge, carrying out mixing to obtain a uniform mixture,
processing the mixture to obtain particles, heating the particles at a temperature of 90-110 DEG C for 4-6min, carrying out
microwave heating at a temperature of 300-500 DEG C, feeding
oxygen into the particles, carrying out
roasting for 10-30min so that trivalent arsenic in the sludge is oxidized to form pentavalent arsenic, continuously feeding
oxygen into the sludge, carrying out microwave heating at a temperature of 500-700 DEG C, and carrying out heat preservation for 20-40min so that trivalent arsenic is further oxidized and
organic arsenic obtained by oxidizing roasting
cracking in the step C is further oxidized and decomposed. The arsenic-containing sludge is subjected to microwave
catalytic oxidation so that curing effects are improved, process is simple, roasting time is short, a temperature is low, no secondary
pollution is produced in the whole process, arsenic-containing sludge stacking-caused environmental
pollution problem is solved, and good
economic benefits, environmental benefits and
social benefits are obtained.