Soil washing using mineral processing plant in Hanaoka Mine, Dowa Mining Co., Ltd.

In Hanaoka Mine, which was one of the major "black ore" (Kuroko) mines in the north part of Japan, mining has finished in 1994, and only mineral processing plant is available now. Recently this mineral processing plant has been applied to the soil washing. Soils contaminated with heavy metals are excavated and transported to the plant. The soils are separated to cleaned soil and metal enrichment through the process which consists of scrubbing, classification, extraction, insolubilization, flotation, and so on. The process is flexibly designed for each contaminated soil, in order to the products can be recycled as cleaned soils or metal sources. Soils contaminated with arsenic and lead were treated in 1999, which were entrusted from Environmental Agency of Japan.