Recent Research and Development on Dissolution and Release of Contaminants in Mineral Products

The consumption of raw ore and ore concentrate and the product of tailings are currently very high in China. The hazardous and toxic contaminants released from mineral products have become a general environmental problem. In this paper the components of contaminants in mineral products and recent research involving them is briefly introduced. The four different leaching simulation experiments of humidity cell, column, static immersion and extraction are discussed in this paper. The humidity cell experiment can simulate natural weathering reactions of products and determine the dissolution rates of contaminants and related products. The column experiment can simulate hydrometeor or drench conditions to provide the kinetic basis for both adsorption and desorption. The static immersion experiment can simulate immersion processing in water, in order to study the release law and related products. The extraction experiment can be used to conduct chemical morphological analysis for contaminants to evaluate the mobility and stability of contaminants in a medium. Various impact factors for contamination dissolution are summarized. Influencing factors in order of strong to weak were pH, leaching or soaking time, temperature, and solid-liquid ratio and ore particle size. In most cases, the higher the pH, the longer leaching or soaking time, the higher the temperature, the smaller solid-to-liquid ratio and the smaller the mineral products particle size, the easier to leach contaminants. Leaching of contaminants was found to be a long-term and latent process. There was a series of physical and chemical reactions that took place inside the products, which indicated the different leaching rules with the diffusion effect. At present, the object of this study is mainly focused on tailings, however, the leached contaminants from the stacked raw ore and ore concentrate products for human use need further research. Leached contaminants need to be predicted and assessed in order to take effective measures to control or manage pollution from mineral ores.