Mineral Processing Technologies for the Remediation of Soils Polluted by Trace Elements

Abstract

Soil washing is a remediation technology based on the adaptation of techniques habitually used in mineral processing to recover contaminants from polluted soils. Its main scope is the reduction of the total volume of contaminated soil, which could later be treated by biological, chemical, or thermal procedures. Since the contaminants are usually associated to the soil finer fractions, direct classification is the most widely employed technique. Moreover, other procedures, such as indirect classification, density and magnetic separation, as well as froth flotation are also extended. Soil washing is usually applied by means of on-site mobile plants which are located in the study sites. However, previously to these field applications, a detailed soil characterization and some trials are required in order to optimize the process. In this work, soils affected by heavy metals as a result of mining, metallurgical, and industrial activities are evaluated and pilot-scale treated. The diversity of soils and residues treated, together with the variety of the methodologies employed enabled the elaboration of a general feasibility protocol.

Keywords

• soil pollution
• mineral processing
• soil washing
• heavy metals