Plasma in-flight treatment of electroplating sludge

Plasma melting is one of the best ways to treat effectively a wide variety of wastes. The present study is focused to develop a new plasma recycle pro cess for hazardous wastes, especially for electroplating sludge, which cont ains several percentages of heavy metals such as Ni and Cr. In-flight treat ments of electroplating sludge were made by DC non-transferred are with dif ferent plasma environments at reduced pressure. X-ray diffraction (XRD) res ults revealed the phase composition of both treated powders and deposits. D eposits prepared from N-2-O-2 plasma showed thermal stability. From energy dispersive X-ray spectroscopy (EDX) elemental analysis, it is found that he avy metals such as Ni, Cr and Zn are concentrated in collected powders. In this process both recovery of Ni and Cr metals and converting of residual s ludge into non-leachable slag are being pursued. (C) 2000 Elsevier Science Ltd. All rights reserved.