Search Results (4)

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. Full article

There are significant tin reserves in the dumps and tailings from Llallagua. Currently, this waste is being processed using gravity concentration or a combination of gravity concentration with a final stage of froth flotation. A process mineralogy study of the tailings and their products after processing in Llallagua was carried out to determine the failings of the processing system in order to contribute to designing an improved new processing scheme. The mineralogy of the feed tailings, concentrate, and final tailings was determined by X-ray diffraction, scanning electron microscopy, and mineral liberation analysis. The tailings were composed of quartz, tourmaline, illite, K-feldspar, plagioclase, cassiterite, rutile, zircon, and monazite. The concentrate essentially contains cassiterite (57.4 wt.%), tourmaline, quartz, hematite, rutile and rare earth minerals, mainly monazite and minor amounts of xenotime and florencite. The concentrate contained 52–60 wt.% of SnO₂ and 0.9–1.3 wt.% REE. The final tailings contained 0.23–0.37 wt.% SnO₂ and 0.02 wt.% of Rare Earth Elements (REE). Only 57.6 wt.% of cassiterite from the concentrate was liberated. The non-liberated cassiterite was mainly associated with quartz, tourmaline, and rutile. The average grain size of monazite was 45 µm and 57.5 wt.% of this was liberated. In other cases, it occurs in mixed particles associated with tourmaline, quartz, cassiterite, and muscovite. To improve the sustainability of this mining activity, the concentrate grade and the metal recovery must be improved. Reducing the particle size reduction of the processed tailings would increase the beneficiation process rates. In addition, the recovery of the REE present in the concentrate as a by-product should be investigated. Full article

A concentrate obtained from mining tailings containing mainly cassiterite and columbotantalite was reduced for the production of tin metal. The compounds CaCO₃, Na₂CO₃, K₂CO₃, and borax were used as fluxes in the pyrometallurgical reduction smelting process, and graphite was employed as the reducing agent. The greatest recovery of Sn (>95%) was obtained when using CaCO₃ as the flux; the purity of Sn was 96%. A slag equivalent to 25% of the mass of the initial concentrate was produced during the recovery of the Sn. This contained 45% Nb₂O₅ and Ta₂O₅, adding extra value to the mine tailings. The tin metal ingot was purified by electrorefining involving a tin and H₂SO₄ electrolyte solution and a 101.9 A/m² current applied for 148 h. Under these conditions, 90 wt % of the Sn in the ingot was recovered at a purity of 99.97%. Full article

Tajikistan has abundant copper–tin resources. In this study, mineralogical analysis of copper–tin ores from the Mushiston deposit of Tajikistan indicates that tin mainly occurred in mushistonite, cassiterite, and stannite, while copper mainly occurred in mushistonite, malachite, azurite, and stannite. The total grades of tin (Sn) and copper (Cu) were 0.65% and 0.66%, respectively, and the dissemination size of copper–tin minerals ranged from 4 μm to over 200 μm. Coarse particles of copper–tin minerals were partially recovered by shaking table concentrators with a low recovery rate. Based on the mineralogical analysis, flotation recovery was used for the first time on the fine particles of copper–tin minerals, including mushistonite, from shaking table tailings. Single factor flotation experiments, open circuit flotation tests, and closed circuit flotation tests were performed to determine the optimized flotation conditions. Results indicated that benzohydroxamic acid (C₆H₅CONHOH) and lead nitrate could effectively recover the mushistonite, cooperating with other depressants. The final concentrate contained 13.28% Sn, with a recovery rate of 61.56%, and 18.51% Cu, with a recovery rate of 86.52%. This method proved effective for the exploitation and use of this type of copper–tin resource in Tajikistan. Full article