Performance Evaluation and Optimization of the REFLUX Flotation Cell (RFC) in Processing Kupferschiefer-type Copper Ore
Abstract
The demand for metals continues to surge, necessitating advancements in mineral processing technologies to increase production capacity and efficiency. Flotation, a predominant method for separating valuable minerals from an ore, remains critical in this context. However, current reserves are insufficient to meet growing demands, driving the need for higher throughput processing and innovative exploration techniques.
This PhD project focuses on assessing and optimizing the performance of the REFLUX Flotation Cell (RFC) in processing, a novel technology in mineral processing. The performance of the RFC was evaluated, and flotation conditions were optimized using copper sulfide ore, which is originated from the Kupferschiefer deposit, processed by the KGHM Polkowice Copper Concentrator (Polkowice, Poland).
The thesis was structured on four research questions (RQ). In RQ 1, the effects of operating parameters on the flow type and residence time distribution (RTD) within the RFC was investigated. RTD measurements were conducted in a two-phase liquid-gas system using a RFC-100 unit. The impulse response method was employed, where concentrated potassium chloride (KCI) tracer solution was injected into a feed inlet after achieving steady-state conditions. Conductivity measurements were taken from the underflow outlet to track the tracer's movement. Various operating conditions, including bias flux, feed flux, and gas flux, were tested to assess their effects on RTD. The RTD data were modeled using different approaches (1 Large and 2 Small Tanks in Series (1L2STS), 1 Large and 1 Small Tank in Series (lLlSTS), N tank-in-series, and Perfect Mixer models), and the mean residence time (MRT) was calculated to evaluate fluid behavior within the system. The results revealed that the fluid behavior within the RFC-100 tended towards a plug flow pattern rather than perfect mixing. Despite varying the experimental conditions, the shapes of the RTD curves remained largely unchanged, and the MRT values consistently stayed below 60 seconds, indicating a low residence time and a plug flow tendency. It was also observed that increasing the gas flux led to a decrease in MRT and shifted the maximum tracer concentration upward within the cell, emphasizing the significant impact of gas on the mixing regime. Among the factors studied, the feed flux was identified as the most influential on MRT, followed by the bias flux, while the gas flux had a comparatively minor effect. The strong correlation between the calculated and measured MRT values suggested that there were no dead zones in the system, confirming the accuracy of the RTD measurements In RQ 2, the optimal collector system for the Kupferschiefer type copper ore used was studied. Thiol collectors commonly used for copper sulfide flotation were reviewed, screened, and tested to identify the most effective reagents. The study focused on three primary collectors: AEROPHINE®3422, AERO®MX 5149, and NAX, which were selected after initial screening for further evaluation, A series of 42 flotation experiments were conducted with varying dosages and combinations of the three selected reagents. Statistical methods, including linear and nonlinear regression, as well as machine learning models. Such as Random Forests and Genetic Programming, were applied to predict flotation outcomes and optimize reagent combinations. A sensitivity analysis was performed to understand the impact of each reagent on the flotation performance. The study successfully identified optimal reagent combinations and dosages and provided insights into the synergistic effects of different reagent mixtures on copper recovery and grade.
In RQ 3, it was examined whether the RFC can increase the flotation efficiency under the same collector system and eliminate the use of xanthates in the flotation process. This study tested the reagent system optimized in RQ 2, using the same reagents but under different grinding conditions. The tests involved varying dosages of three reagents (NAX, AEROPHINE® 3422, and AERO® MX 5149) under specific operating conditions. Flotation performance was assessed using flotation kinetics, grade-recovery
Has parts
Paper 1: Güner, Mustafa Kadir; Hassanzadeh, Ahmad; Vinnett, Luis; Yianatos, Juan; Kowalczuk, Przemyslaw Boguslaw. Effects of operating parameters on residence time distribution in a REFLUX flotation cell. Minerals Engineering 2023 ;Volum 204. s. - Published by Elsevier Ltd. This is an open access article under the CC BY license. Available at: http://dx.doi.org/10.1016/j.mineng.2023.108439Paper 2: Güner, Mustafa Kadir; Hassanzadeh, Ahmad; Vinnett, Luis; Yianatos, Juan; Kowalczuk, Przemyslaw Boguslaw. (2022). Residence Time Distribution Measurements and Modeling of Lab-Scale Imhoflot™ Pneumatic Flotation Cell and REFLUX™ Flotation Cell. Proceedings of the 17th IMPS, 393-401.
Paper 3: Güner, Mustafa Kadir; Akyildiz, Ozge; Basarir, Hakan; Kowalczuk, Pshem. Exploring the impact of thiol collectors system on copper sulfide flotation through machine learning-driven modeling. Physicochemical Problems of Mineral Processing 2024 ;Volum 60.(4). Published by Technical University of Wroclaw. Open access. Available at: http://dx.doi.org/10.37190/ppmp/191709
Paper 4: Güner, Mustafa Kadir; Lode, Stefanie; Malafeevskiy, Nikita; Aasly, Kurt; Kowalczuk, Pshem. Mixed thiol collector system in the flotation of copper ore using the REFLUX Flotation Cell (RFC). Minerals Engineering 2024 ;Volum 216. s. 1-15. Published by Elsevier Ltd. This is an open access article under the CC BY license. Available at: http://dx.doi.org/10.1016/j.mineng.2024.108843
Paper 5: Güner, Mustafa Kadir; Kowalczuk, Pshem (2024). Impact Assessment and optimization of REFLUX Flotation Cell (RFC) Primary Settings on Copper Sulfide Ore Flotation (RFC) Available at SSRN: http://dx.doi.org/10.2139/ssrn.4970573.
Paper 6: Güner, Mustafa Kadir; Kowalczuk, Pshem (2024). Optimization of Operating Condition of REFLUX Flotation Cell (RFC) for Copper Sulfide Ore. XXXI IMPC-International Mineral Processing Congress 2024, Proceedings 2974-2982. © 2024 SME All Rights Reserved. This paper is not included due to copyright restrictions.