In-field remediation of tons of heavy metal-rich waste by Joule heating vitrification

An in-field remediation method of tons of Pb and Zn-rich ceramic waste based on Joule heating vitrification is presented. The progressive heating up to about 1850 °C led to the complete melting of the waste material and the rapid cooling of the melt formed a monolithic glass of 55 tons. The obtained glass was chemically and morphologically homogeneous and immobilized the heavy metals and non-volatile inorganic compounds. The occurrence of crystalline phases such as zircon and cordierite was observed in the lowermost part of the monolith due to the different cooling rate. Leaching tests showed that the vitrified monolith presented a high chemical resistance and metal ions were immobilized into the glass matrix. The presented in-field vitrification process was highly effective in the remediation of tons of heavy metal-rich materials and can be exploited further for remediation of large amounts of soils and asbestos-based materials.