PROCESS FOR THE TREATMENT OF ARSENIC-CONTAINING SLUDGE

摘要

The present invention relates to a process for the treatment of arsenic-containing sludge obtained by adjusting arsenic-containing waste water to a PH of 12 or greater by the addition of a calcium compound and subjecting the waste water to solid-liquid separation, the process comprising the steps of adding a calcium compound to the arsenic-containing sludge slurry obtained by the solid-liquid separation, dewatering the resulting sludge, drying the dewatered sludge, and calcining the dried sludge. According to the present invention, arsenic-containing sludge obtained by treating waste water to precipitate arsenic present therein can be calcined to yield a calcined product which involves no risk of arsenic redissolution when it is dumped. Moreover, there is no possibility that arsenic compounds may be volatilized during calcination.