Development of a high-gradient magnetic separator for enhancing selective separation: A review

High-gradient magnetic separation (HGMS) has become the most common means of selectively enriching fine weakly magnetic minerals and purifying non-metal ores. However, with the increasing challenge of the global mining industry to confront declining grades and low-grade orebodies, higher selectivity is required to keep HGMS competitive. In this context, the current review attempts to summarize and refresh efforts regarding the selective separation of HGMS. Reasons for deteriorating selective separation, effects of applied forces, methods of selectivity improvement, and derivative industrial separators are systematically reviewed. On the basis of these descriptions, the future trends in HGMS should be directed toward the highly selective separation of ultrafine materials by enhancing particle dispersion, increasing the magnetic field force, and introducing more efficient competitive forces. These breakthroughs and innovations in selectivity problems may further extend the applicability of HGMS to a wider spectrum of industrial fields.