Non-solvent Based Surface Treatments for Sustainable Mineral Processing Applications

Author: Jennifer Johnson, Department of Materials and Metallurgical Engineering

Contributor: Bernardo Moreno Baqueiro Sansão, Department of Materials and Metallurgical Engineering

Mentor: Dr. Jon Kellar, Department of Materials and Metallurgical Engineering

Mentor: Dr. William Cross, Department of Materials and Metallurgical Engineering

Mentor: Dr. Albert Romkes, Department of Mechanical Engineering

Many mineral and metallurgical processes involve the use of water. For example, froth flotation requires the use of water and other solvents with collectors, pH modifiers, and surfactants to achieve separation based upon differences in surface properties. New, more sustainable practices are of critical importance to the future of ore treatment. This investigation evaluates non-solvent based surface treatment of minerals prior to separation. The overall project goal is to reduce the usage of solvents for ore processing. Thus, a non-solvent treatment was performed by mixing ground minerals (quartz, microcline, calcite, and hematite) with chemical treatments (trichloro(octadecyl)silane, and trimethoxysilylpropyl diethylenetriamine) in a planetary centrifugal mixer. Next, the interfacial energy of the dry blended minerals was evaluated. These measurements showed that the hydrophobic character of the particles resulted because of dry blending treatment. Additionally, ground minerals, like fluorite (CaF₂) with oleic acid (C₁₈H₃₄O₂) have been tested to show continual trends of hydrophobicity and working towards the goal of separation due to specific surface properties. Ongoing work includes testing the fluorite and oleic acid combinations and future combinations, at different humidity levels.