Thermal plasma treatment of electroplating sludge

Summary form ony given, as folllows. 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 process for hazardous wastes, especially for electroplating sludge, which contains several percentages of heavy metals such as Ni & Cr. In-flight treatments of electroplating sludge were made by a DC non-transferred arc with different plasma environments at reduced pressure. XRD results revealed the phase composition of both treated powders and deposits. Deposits prepared from N/sub 2/-O/sub 2/ plasma showed thermal stability. From EDX elemental analysis, it is found that heavy metals such as Ni, Cu and Zn are concentrated in the collected powders. Results of XRF showed that dependency of the plasma gas composition and specific enthalpy of the plasma on recovery of heavy metals from the sludge. The N/sub 2/-O/sub 2/ plasma showed good results on total recovery of heavy metals compared to others. In this process both recovery of heavy metals and converting of residual sludge into non-leachable slag are being pursued.