The paper presents a comparison of the concentration methods conventional jig, air jig, and sensor-based sorting to treat construction and demolition waste. All tests were made with concrete, brick, and gypsum particles and the tests aim to separate these materials into different size ranges, depending on the method. The equipment tested, conventional jig, air jig, and sensor-based sorting present good results to concentrate construction and demolition waste particles, with different concentrations and mass recoveries. The results show particularly good mass recoveries and particle concentration for conventional jig, especially for concrete and gypsum particles. Sensor-based sorting should preferably use concentration circuits for best results.

Stability of bubble size in the pulp zone and froth control is an important parameter for a successful flotation process. The present study compares the action of the main frothers in terms of: mean bubble size in the pulp zone, froth stability, surface-tension-lowering ability and reagent participation in flotation of a naturally hydrophobic mineral. Bubble size was determined using a new technique adapted from HYDROMESS, a device designed to measure drop size. The remaining indicators were obtained by determining surface tension and conducting flotation tests with the addition of hydrophobic (graphite) and hydrophilic (calcite) particles. The results indicate that methyl isobutyl carbinol (MIBC) is the most efficient frother in controlling coalescence, with critical coalescence concentration (CCC) reached at 20 ppm. Moreover, this frother has greater potential for selective action, since it increased calcite entrainment by only 2.3% at a concentration of 30 ppm. In flotation tests with a sample of graphite, MIBC produced higher recoveries.

Asbolane is a secondary source of cobalt (Co) and manganese (Mn), essential for battery and alloy production. Enhancing the utilization of low-grade ores, typically containing ~1.2% Co and 14.7% Mn, is vital for conserving high-grade resources. However, fine grinding for such ores presents challenges for conventional gravity separation. This study investigates the effectiveness of the Multi-Gravity Separator (MGS) in processing finely disseminated asbolane ore from Agios Ioannis, Greece. The study was conducted at the Mineral Processing Laboratory of UPC/Bases Manresa. Two size fractions, D₈₀ (−100 +50 µm and −50 µm), were tested under varying drum speeds, tilt angles, and wash water flows. Response surface methodology (RSM) was implemented using Python-optimized (version 3.15) process parameters. The results demonstrate that a concentrate with 2.6% Co and 32.5% Mn can be obtained, achieving 82.1% Co recovery. Independent and multi-objective optimizations confirm MGS as a viable method for recovering Co and Mn from complex low-grade ores, with reduced overgrinding-related energy losses essential for production. The study aimed to implement and enhance low-grade asbolane ore from a feed containing 2.6% Co and 32.5% Mn. Variables were optimized with a multi-objective target, demonstrating their effectiveness.

In recent decades, there has been an upsurge in focus on the extraction of pyrite from sulfide ore deposits due to its vital role in the process of metal extraction and environmental management. This study explores the flotation behavior of pyrite in sulfide ores using mechanical-cell flotation. This study compared the performance of two commonly used flotation collectors, potassium butyl xanthate (KXT) and diethyl dithiophosphate (DTP), in the beneficiation of a sulfide ore from southwestern Spain. Statistical analysis performed using MiniTab 4.0 revealed that collector type, reagent dosage, and pulp pH were the principal factors affecting pyrite recovery. Under the tested conditions, KXT exhibited superior metallurgical performance and selectivity compared with DTP. The flotation kinetics demonstrate that the chemical was more efficacious throughout both the rougher and cleaner phases of the process. The findings robustly corroborate the notion that employing xanthate-based chemicals to enhance pyrite concentration facilitates metal extraction from the Sulfide Ore Deposit in southwestern Spain. The study sets out a basis for process growth, and it is proposed that further research be conducted under industrial water conditions to validate the findings.

Waste deposits from the Iberian Pyrite Belt that are rich in pyrite are a valuable secondary resource for getting back sulphide minerals and important metals that go with them. This study assessed the efficacy of a Multi-Gravity Separator (MGS) in concentrating pyrite and related polymetallic minerals from sulphide waste material sourced from the Alonso mining district (Huelva, Spain). Bench-scale MGS tests were done on two particle size fractions (−500 µm and −50 µm) to see how the speed of the drum rotation, the angle of the tilt, and the flow rate of the wash water affected the separation efficiency. Mineral Liberation Analysis (MLA) showed that both size fractions had about 65.8 wt% pyrite, but the −50 µm fraction was much more liberated. Under the best operating conditions, the MGS was able to recover about 58% of the pyrite from the −500 µm fraction and about 64% from the −50 µm fraction. The mass recoveries were about 38% and 42%, respectively. There was also a better recovery of related metals like Co, Cu, Zn, and Mn, especially for the finer fraction. This shows the improvement of the liberation and stratification behaviour. The results show that MGS is a good way to pre-concentrate fine-grained pyrite-rich waste. The performance is heavily influenced by the size distribution of the particles and the operating parameters. These results suggest that improvements in gravity separation may offer a long-term pathway for the recycling of sulphide mine waste within a circular economy.