Separation Techniques for Flotation and Recycling in Mineral Processing

Dear Colleagues,

Froth flotation, which is a crucial technique in mineral processing, exploits the differences in the surface hydrophobicity of the various constituent minerals and selectively separates valuable minerals from gangue by attaching them to air bubbles and recovering them from the mineral-laden froth. The combination and scheme of flotation reagents such as collectors, frothers, and modifiers can dramatically increase the efficiency of the flotation process, leading to higher recoveries of valuable minerals. This technique is particularly effective in separating sulfide minerals, oxide minerals, etc. from gangue materials, making it an indispensable tool in the processing of ores containing copper, lead, zinc, nickel, and other valuable metals. Furthermore, column flotation is an advanced mineral processing technique that offers several advantages over conventional flotation. Its reduced turbulence, deep froth bed, and wash water system effectively minimize the entrainment of fine gangue minerals, resulting in cleaner concentrates and improved recoveries.

Resource recycling is a key component of sustainable resource management. The benefits of recycling include resource conservation, energy savings, pollution reduction, and economic advantages. Mineral processing and hydrometallurgy, typically used in recycling methods, are essential for recovering valuable materials from waste in various applications, including e-waste, batteries, catalytic converters, solar panels, PCBs, steel dust, automotive shredder residue, and wastewater treatment. By effectively integrating mineral processing and hydrometallurgy, the efficient and sustainable recycling of valuable materials can be achieved, contributing to a circular economy and resource conservation.

This Special Issue welcomes recent advanced technologies in the areas of theory, mechanisms, process control, chemical reagents, surface characteristics, dynamics, and separation efficiency related to froth flotation, mineral processing, hydrometallurgy, and resource recycling.

Dr. Chulhyun Park
Dr. Hoseok Jeon
Guest Editors

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• flotation
• bubble size
• gas dispersion property
• surface chemistry
• sulfide/oxide minerals
• reagents
• technical theory/mechanisms
• process control
• dynamics
• separation efficiency
• mineral processing
• hydrometallurgy
• recycling
• waste

Title: Estimation of bubble size and gas dispersion property in column flotation
Authors: HyunSoo Kim; Chul-Hyun Park
Affiliation: Department of Advanced Energy Engineering, Chosun University, Gwangju 61452, Korea
Abstract: This study investigates bubble size measurements, bubble characteristics, and the relationship between key operating variables and gas dispersion properties in column flotation. The bubble size and gas holdup were measured using a manometer, high-speed camera, and image analysis program. The critical coalescence concentration (CCC) was identified as 120 ppm, above which the frother concentration minimally impacted the surface tension and effectively prevented bubble coalescence. Increasing the frother concentration from 30 to 120 ppm transformed the bubble size distribution (BSD) from bimodal to unimodal, achieving a minimum bubble size of 0.45 mm. Gas velocity and wash water velocity significantly influenced bubble size, with gas holdup peaking at 27% at 1.08 cm/s a gas velocity. The bubble surface area flux decreased linearly with increasing bubble size and was significantly affected by the gas velocity. A strong correlation (R² = 0.86) between measured and calculated bubble sizes was achieved, with an average size of 0.64 mm and estimation error of ±13%. The study demonstrated that bubble size and distribution could be effectively controlled under specific operational conditions (Jg = 0.65-1.3 cm/s, JW = 0.13-0.52 cm/s, frother = 30-150 ppm). These findings highlight the importance of optimizing key variables to enhance column stability, regime maintenance, and flotation performance.

Title: Systematic analysis of pyrargyrite mineral flotation collectorless
Authors: M. Reyes-Pérez1, M. Pérez-Labra1*, J. A. Romero-Serrano2, M. U. Flores-Guerrero3, A. Cruz-Ramirez 2, Iván A. Reyes Domínguez 4, F. Patiño-Cardona5, L. P. Angeles-Palazuelos1
Affiliation: 1 Academic Area of Earth Sciences and Materials. Autonomous University of Hidalgo State. Road Pachuca- Tulancingo Km 4.5 Mineral de la Reforma Zip Code 42184, Hidalgo México. 2 Metallurgy and Materials Department, ESIQIE-IPN. UPALM, Zacatenco, Zip Code 07738, México. 3 Industrial Electromechanics Area, Technological University of Tulancingo, 43642 Hidalgo, México. 4 Instituto de Metalurgia, Universidad Autónoma de San Luis Potosí, San Luis Potosí 78210, México 5 Consejo de Ciencia, Tecnología e Innovación de Hidalgo Science Building, Exhacienda de la Concepción 3, La Concepción, 42162, Hidalgo, México.
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