Extracting iron while minimizing the health and environmental risks associated with arsenic contamination necessitates the removal of arsenic from arsenic-bearing iron ores to ensure a safe and sustainable supply of this metal for industries. The beneficiation of iron minerals and arsenic-bearing minerals from arsenic-bearing iron ores with a calcification-magnetizing roasting and low-intensity magnetic separation (CMR-LMS) process is investigated in this work. The results show that the process is successful in extracting iron minerals and eliminating arsenic-containing minerals. The roasting involves two key steps: calcification and magnetizing, which change hematite and goethite into magnetite and arsenic-bearing minerals into calcium arsenates. The process’s separation efficiency of the CMR-LMS is closely linked to the parameters such as roasting temperature, roasting time, coke, alkalinity, and the liberation of gangue minerals from iron minerals. Through grinding and secondary magnetic separation, the iron minerals and gangue components, as well as arsenic, in roasted sand can be further separated. The optimum procedure results in a high-grade iron concentrate with an iron assay of 65.65%, an Fe recovery rate of 80.07%, and an arsenic content of 0.085%, while achieving a 93.29% As removal rate from the original ore that has 45.32% Fe and 0.70% As.

Tin-containing tailing is classified as a solid waste, but it possesses valuable resources such as tin and iron. Tin-containing tailing exhibits a fine distribution and compact symbiosis of cassiterite- and iron-containing minerals. Therefore, it is difficult to recover and separate cassiterite- and iron-containing minerals using traditional mineral processing methods. The study proposed a novel technology involving pre-concentration, reduction roasting, and magnetic separation for the treatment of tin-containing tailings with a tin grade of 0.14% and an iron grade of 12.79%. The classification pre-concentration method was achieved using a combination of shaking tables, suspension vibration cone separators, and high-gradient magnetic separation with a magnetic field strength of 1.4 T. The discarded tailings ratio reached 73.56%. The gravity pre-enriched concentrates and magnetic pre-enriched concentrates underwent reduction roasting to facilitate the conversion of hematite and goethite into magnetite, respectively. The optimal conditions for reduction roasting of the gravity pre-enriched concentrate were a 10% lignite dosage, a roasting temperature of 650 °C, and a holding time of 80 min. The optimal conditions for reduction roasting of the magnetic pre-enriched concentrate were a 8% lignite dosage, a roasting temperature of 750 °C, and a holding time of 100 min. The reduction roasted products were treated using magnetic separation with a magnetic field strength of 0.16 T. Finally, a tin-rich middling with a tin grade of 2.93% and a recovery ratio of 70.88%, as well as an iron concentrate with an iron grade of 61.95% and a recovery ratio of 68.08% were obtained. The study achieved efficient recoveries of tin and iron from tin tailings, thereby presenting a novel approach for the utilization of resources in the tailing.

To explore the flotation feasibility and flotation law of iron minerals from amphibole-type iron oxide ore with full-size minerals, a systematic study on the flotation behaviors of single minerals hematite, quartz, and amphibole was carried out with the anionic reverse flotation system. The effects of collectors, depressants, activators, and pH on the floatabilities of three single minerals was investigated. The flotation separations of binary mixed minerals and ternary mixed ores were carried out, respectively. The study results show that CaCl₂ is adsorbed on the surfaces of quartz and amphibole, which can activate them. The hydroxyl groups of the starch molecular chain were adsorbed on the surfaces of the hematite and amphibole in the form of hydrogen bonds, but were hardly adsorbed on surface of the quartz. Therefore, both hematite and amphibole were depressed, resulting in a poor separation effect of the three single minerals in the anionic flotation system.

Direct cyanide leaching of high-carbon gold ores typically results in poor gold extraction due to the “preg-robbing” effect of carbonaceous matter. This study investigates a refractory high-carbon gold ore from Laos. Based on detailed process mineralogy that identified the occurrence state of gold and the distribution of harmful impurities, a combined process consisting of flotation pre-concentration, oxidative roasting, and a Mill–Leach Coordination (MCL) process was developed. The MCL process, which integrates simultaneous grinding and leaching, continuously renews the particle surface and eliminates product-layer diffusion resistance, thereby significantly enhancing gold dissolution efficiency. Kinetic studies demonstrate that the leaching reaction follows the Avrami model and is controlled by internal diffusion, with a derived semi-empirical kinetic equation. This research provides a novel and efficient technical route for treating high-carbon gold ores and offers theoretical guidance for industrial scale-up.

The quality of sintering ore and the efficiency of the blast furnace are both heavily dependent on the high-temperature performance and compatibility of iron ores. A novel characterization technique, the Assimilation Melt Breakover method, is proposed to test the electrical performance during assimilation in sintering. Utilizing the two-electrode method, the electrical resistance of mixtures of ferrite oxide and calcium oxide was measured during their assimilation. A rise in temperature is associated with a reduction in electrical resistance, adhering to the principles of Arrhenius Law. The changes in conductivity observed during the assimilation process accurately reflect the mineral phase transformations, encompassing alterations within the solid state and transitions from solid to melt. The transition is marked by a substantial reduction in electrical resistance, specifically from several thousand to a few dozen Ohms in melting assimilation, along with notable variations in the activation energy associated with conductance. This research has the potential to swiftly differentiate between the assimilation characteristics of different iron ores, as well as to assist in the utilization of an electric field in iron ore sintering.