Minerals Engineering最新文献

{"title":"Extraction of precious metals from waste printed circuit boards using alkaline ferricyanide solutions: An exploratory study","authors":"Huan Li ,&nbsp;Elsayed Oraby ,&nbsp;Jacques Eksteen ,&nbsp;Wenhao Xie ,&nbsp;Jing Gu ,&nbsp;Haoran Yuan","doi":"10.1016/j.mineng.2024.109144","DOIUrl":"10.1016/j.mineng.2024.109144","url":null,"abstract":"<div><div>Precious metals leaching using conventional processes presents challenges due to the use of toxic, expensive, and complex leaching systems, such as cyanidation, thio-systems, and halide systems comprising both lixiviant and oxidant. The present study employed a simple leaching system of alkaline ferricyanide solution with dual functions of leaching and oxidization, to extract precious metals from waste printed circuit boards (PCBs). The ferricyanide concentration, pH and temperature were found affecting Au extraction considerably. The selective extraction of Au, Ag and Pd over base metals reached 68.3, 93.0 and 74.0 % (10 g/L ferricyanide, pH 11 and 80℃), respectively. The recovery of precious metals from leachate using carbon adsorption and the regeneration of ferricyanide from barren solutions employing ferri/ferrocyanide redox cycle were shown feasible. Around 91.7 % ferricyanide could be regenerated by oxidising ferrocyanide using potassium permanganate. Finally, conceptual flowsheets were proposed to extract and recover precious metals and to regenerate and reuse the only reagent introduced ferricyanide. The study proved the feasibility of the simple leaching method, paving the way for future development of the new process.</div></div>","PeriodicalId":18594,"journal":{"name":"Minerals Engineering","volume":"222 ","pages":"Article 109144"},"PeriodicalIF":4.9,"publicationDate":"2024-12-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142790161","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Mechanism of synergistic effect of aluminum ions and water glass on talc flotation depression","authors":"Tao Long ,&nbsp;Qubing Li ,&nbsp;Wei Yang ,&nbsp;Sha Deng ,&nbsp;Xiangyu Peng ,&nbsp;Jianping Jin","doi":"10.1016/j.mineng.2024.109127","DOIUrl":"10.1016/j.mineng.2024.109127","url":null,"abstract":"<div><div>Talc, a prevalent gangue mineral in sulfide ores, poses a significant challenge in the flotation process due to its good floatability. The application of water glass as a standalone reagent has been found to be less effective in suppressing talc. In this study, we delve into the synergistic inhibitory mechanism of Al³⁺ in conjunction with water glass on talc through a series of micro-flotation tests, wettability tests, ICP-MS tests and FTIR spectroscopy tests. Our findings demonstrated that the presence of Al³⁺ significantly enhanced the adsorption capacity of water glass on talc surface. Talc recovery was 23.34 % with the addition of both inhibitors, which was lower than the recovery of 55.82 % with the addition of water glass only. DFT calculation revealed that the adsorption of H₄SiO₄ and [H₃SiO₄]⁻ on the talc surface is relatively weak, with adsorption energies of −7.71 kJ/mol and −23.15 kJ/mol. Following the adsorption of Al³⁺ onto the talc surface, the adsorption energies of H₄SiO₄ and [H₃SiO₄]⁻ were further decreased to −78.41 kJ/mol and −119.63 kJ/mol. The presence of Al³⁺ significantly enhanced the interaction between water glass and the talc surface. This enhancement was attributed to the formation of hydrogen bonds between water glass and the Al³⁺ water complex–Al(OH)₃·H₂O, which augmented the interaction with the talc surface.</div></div>","PeriodicalId":18594,"journal":{"name":"Minerals Engineering","volume":"222 ","pages":"Article 109127"},"PeriodicalIF":4.9,"publicationDate":"2024-12-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142790051","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Dynamics of gas dispersion in a rising bubble plume in presence of surfactant","authors":"Abdullaziz Glabe Zakari,&nbsp;Mohammad Mainul Hoque,&nbsp;Peter Ireland,&nbsp;Geoffrey Evans,&nbsp;Subhasish Mitra","doi":"10.1016/j.mineng.2024.109145","DOIUrl":"10.1016/j.mineng.2024.109145","url":null,"abstract":"<div><div>Understanding dispersion behaviour of bubbles emitting from a sparger is a critical element of mineral flotation process. This aspect was investigated in the present study involving a bubble plume in a semi-batch rectangular column in the presence of an anionic surfactant. First, high-speed imaging was used to visualise the bubble plume behaviour at different air flow rates (0.1 – 0.5 L/min). An image processing code was developed to determine the mean bubble diameter which indicated a decrease in the mean bubble diameter from ∼ 0.60 mm to 0.51 mm with increasing gas flow rates. A transient 3D Eulerian-Eulerian multiphase CFD model with a bubble population balance sub-model was also developed to quantify the gas holdup and turbulence energy dissipation rate distribution in this system utilising the experimentally measured mean bubble size. Experimentally, it was observed that symmetry of the bubble plume was disrupted at higher gas flow rates leading to larger dispersion of gas bubbles towards the top of the column. This observation was explained by the CFD model which predicted asymmetric transverse velocity profiles that increased in the axial direction. The model also predicted increasing gas holdup in the system (∼0.02 to 0.11) with increasing gas flow rates. The corresponding turbulence energy dissipation rate increased from ∼ 0.014 to 0.076 m²/s³ with maximum turbulent energy dissipation rate occurring near the gas distributor zone. Also, a transition from a bubbly to a distinct foam zone was noted at the free surface in the higher gas flow rate cases which was explained by the turbulence energy dissipation rate in the system.</div></div>","PeriodicalId":18594,"journal":{"name":"Minerals Engineering","volume":"222 ","pages":"Article 109145"},"PeriodicalIF":4.9,"publicationDate":"2024-12-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142790160","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"New insights into the surface chemical properties of serpentine and flotation of pyrite using xanthomonas campestris as a novel selective serpentine depressant: Experimental and DFT investigation","authors":"Levie Mweene ,&nbsp;Govinda Prasad Khanal ,&nbsp;Emmanuel Etim","doi":"10.1016/j.mineng.2024.109141","DOIUrl":"10.1016/j.mineng.2024.109141","url":null,"abstract":"<div><div>The flotation separation of pyrite (Py) from serpentine (Spt) was studied using xanthamonas campestris (XC) as a novel Spt depressant. The adsorption of XC onto Spt and Py was observed to decrease with increase in pH attesting to increased repulsion between the negatively charged carboxylate portion of XC and the increased negativity of the mineral surface. However, the polysaccharide adsorption onto Py was less than that onto Spt due to a higher <em>iso</em>-electric point (IEP) of Spt compared to that of Py. Further, theoretical investigations using quantum theory of atoms in molecules (QTAIM) revealed that XC adsorption onto Spt was due to hydrogen bonding (HB), partial and non-covalent interactions, whereas that onto Py was due to partial covalent and non-covalent interactions. Additionally and in general, the adsorption of XC onto the minerals was due to the shift of electrons from the polysaccharide to mineral surface species. Flotation studies conducted at pH 7.8 of Py-Spt (1:1) in presence of 20 g/t, 80 g/t and 60 g/t of sodium tripolyphosphate (SPP), XC and potassium amyl xanthate (PAX) yielded Py grade and separation efficiency of 98.7 % and 97.8 %, respectively, at an economical cost. Therefore, XC is a potential depressant for Spt.</div></div>","PeriodicalId":18594,"journal":{"name":"Minerals Engineering","volume":"222 ","pages":"Article 109141"},"PeriodicalIF":4.9,"publicationDate":"2024-12-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142790162","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A new mixture of anionic collectors for improvement of apatite floatability","authors":"Saeed Abdollahi ,&nbsp;Sajjad Afraei ,&nbsp;Akbar Mehdilo ,&nbsp;Reza Kouchakzadeh ,&nbsp;Mehdi Irannajad","doi":"10.1016/j.mineng.2024.109129","DOIUrl":"10.1016/j.mineng.2024.109129","url":null,"abstract":"<div><div>Flotation is the most essential method for the concentration of phosphate reserves and, hence, the production of apatite concentrate. With the reduction of high-grade reserves and the necessity of exploiting low-grade phosphate ores, many efforts have been made to use different chemical reagents alone and their combinations as collectors for apatite flotation and achieving high-quality concentrates for preparing phosphoric acid and fertilizers. This work focuses on applying direct apatite flotation by employing a novel mixture of fatty acid collectors to optimize the apatite processing plants. Extensive experiments using tall oil fatty acid (TOFA) and oleic acid polyethylene glycol ester 6 mol (OAPEGE6) alone and their mixture in different ratios were conducted in micro-flotation, bench flotation, and plant flotation scales. The micro-flotation experiments showed that using OAPEGE6 and TOFA, the flotation recovery of apatite at a pH of 9.5 is 46% and 86%, respectively. However, by mixing TOFA and OAPEGE6 in a weight ratio of 70% to 30%, the flotation recovery of apatite increases to 95%. At this weight ratio of TOFA and OAPEGE6 using a 600 <span><math><mrow><mi>g</mi><mo>/</mo><mi>t</mi></mrow></math></span> mixed collector, an apatite concentrate containing 23.2% <span><math><mrow><msub><mrow><mi>P</mi></mrow><mrow><mn>2</mn></mrow></msub><msub><mrow><mi>O</mi></mrow><mrow><mn>5</mn></mrow></msub></mrow></math></span> with a recovery of 90.4% is achieved by rougher stage bench flotation in laboratory experiments. Finally, using the mixed collector with the formulation mentioned above on a plant-scale, an apatite concentrate with almost 33% <span><math><mrow><msub><mrow><mi>P</mi></mrow><mrow><mn>2</mn></mrow></msub><msub><mrow><mi>O</mi></mrow><mrow><mn>5</mn></mrow></msub></mrow></math></span> and 59% recovery is obtained through rougher and cleaner stages of the flotation process. FTIR analysis and zeta potential measurements show that the simultaneous presence of TOFA and OAPEGE6 with a synergetic effect can strengthen the chemisorption of oleate active species on the apatite surface. As confirmed by contact angle measurements, this improved the formation of an insoluble hydrophobic layer on the apatite surface and resulted in its flotation recovery.</div></div>","PeriodicalId":18594,"journal":{"name":"Minerals Engineering","volume":"222 ","pages":"Article 109129"},"PeriodicalIF":4.9,"publicationDate":"2024-12-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142790054","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Sustainable reprocessing of Pb–Zn mine tailings through froth flotation for resource recovery and environmental remediation in abandoned mining regions","authors":"Abdessamad Khalil ,&nbsp;Yassine Ait-khouia ,&nbsp;Hamza Beniddar ,&nbsp;Mustapha El Ghorfi ,&nbsp;Rachid Hakkou ,&nbsp;Yassine Taha ,&nbsp;Mostafa Benzaazoua","doi":"10.1016/j.mineng.2024.109132","DOIUrl":"10.1016/j.mineng.2024.109132","url":null,"abstract":"<div><div>The abandoned Touissit-Bou Beker mining district has accumulated tens of millions of tons of tailings, stored without environmental safeguards. Due to the limited ore processing method, the tailings exhibit a significant zinc (2 wt%) and lead (0.3 wt%) content, mainly buried in carbonate minerals. These tailings pose environmental concerns but also offer economic opportunities. This study investigated the feasibility of decontaminating these tailings using froth flotation to produce a clean mineral byproduct. Composite samples were collected via reverse circulation (RC) drilling, and flotation conditions were optimized. Quantitative mineralogy and environmental behavior were assessed using quantitative evaluation of materials by scanning electron microscope (QEMSCAN®) and toxicity characteristic leaching procedure (TCLP), respectively. Under optimal conditions — potassium amyl xanthate (KAX) 350 g/t, CuSO₄ 1,250 g/t, Na₂S 1,250 g/t, sodium hexametaphosphate (SH) 1,750 g/t, and pH 11—Zn and Pb recoveries reached up to 94 % and 71 %, respectively. Residual Pb–Zn remained partially locked within the non-sulfide gangue minerals or present as slime particles. TCLP results indicate minimal risk, suggesting reprocessing mine tailings in abandoned mine sites in Morocco could offer economic and environmental benefits. The current study is expected to serve as a reference for decision-makers when evaluating sustainable management options for mine tailings.</div></div>","PeriodicalId":18594,"journal":{"name":"Minerals Engineering","volume":"222 ","pages":"Article 109132"},"PeriodicalIF":4.9,"publicationDate":"2024-11-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142747410","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Model investigation of a dry vibrated fluidized sinkhole system for separating coarse particles based on density","authors":"Dusan Ilic,&nbsp;Aleksej Lavrinec,&nbsp;Kevin P. Galvin","doi":"10.1016/j.mineng.2024.109111","DOIUrl":"10.1016/j.mineng.2024.109111","url":null,"abstract":"<div><div>A simulation model of a dry, vibrated, fluidized medium (VFM) with sinkhole arrangement was developed and used to investigate the separation of relatively dense, coarse particles. The objective of the new model was to emulate a most unusual experimental result involving the sinkhole arrangement, separation densities much higher than the bulk density of the fluidized medium. The VFM was simulated using spherical sand particles <span><math><mrow><mn>225</mn><mspace></mspace><mi>μ</mi><mi>m</mi></mrow></math></span> in diameter, and density of 2500 kg/m³, while spherical coarse particles 2 to 4 mm in diameter, with density ranging from 2100 to 8400 kg/m³, were used as the density tracers. Coupled computational fluid dynamics (CFD)/discrete element method (DEM) was used to simulate interactions for up to 10 s duration. Remarkably, the model reproduced separation densities much higher than the bulk density of the suspension. Different combinations of frequency and amplitude of vibration, air flow velocity, and volume of VFM were used. The separation density was found to scale directly with the amplitude, and scale with the frequency to the 0.33 power. Vibration intensity correlated poorly with separation density. The critical condition governing the tendency of a particle to float or sink was examined in terms of the volume fraction and the density of the bed profile in the vicinity of the sinkhole. A pronounced reduction in the bed density is evident near the base of the VFM for particles that sink. The average solid volume fraction is observed to vary from 0.58 during initial settling, decreasing as the particles sink. Interestingly, re-circulation of the VFM is needed for a tracer particle to sink. Re-circulation is dependent on, and increases with, airflow as the bed expands up to a maximum beyond which it again reduces.</div></div>","PeriodicalId":18594,"journal":{"name":"Minerals Engineering","volume":"222 ","pages":"Article 109111"},"PeriodicalIF":4.9,"publicationDate":"2024-11-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142747414","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Advancements in the extraction of niobium and tantalum: Innovative strategies in hydrometallurgical processes","authors":"Darwin Michell Cheje Machaca,&nbsp;Thamyres Cardoso de Carvalho,&nbsp;Jorge Alberto Soares Tenório,&nbsp;Denise Crocce Romano Espinosa","doi":"10.1016/j.mineng.2024.109125","DOIUrl":"10.1016/j.mineng.2024.109125","url":null,"abstract":"<div><div>This article presents a comprehensive analysis of the challenges and advancements in the extraction of niobium (Nb) and tantalum (Ta), focusing on global production and the growing demand for strategic and critical metals. The extraction of these metals from their primary and secondary resources is carried out through well-known metallurgical techniques, based on the use of hydrofluoric acid in the various production chains. However, the operational processes and their sustainable production are hindered due to the negative impacts produced during the process, resulting in a particular challenge for the extraction of these two metals. Therefore, pyrometallurgical and hydrometallurgical processes have been explored as emerging alternatives to the existing commercial processes. Thermal treatment processes in acidic and alkaline media have been shown to be capable of preparing PLS loaded with the metals of interest. On the other hand, leaching using mineral and organic acids is essential for the efficient recovery of Nb and Ta, highlighting their advantages and limitations. Additionally, the precipitation of acidic or basic liquors from hydrometallurgy is described to advance towards selective recovery stages. In this context, emphasis is placed on traditional and novel extractants according to their separation function, to ensure the high quality of the products through current technology.</div></div>","PeriodicalId":18594,"journal":{"name":"Minerals Engineering","volume":"222 ","pages":"Article 109125"},"PeriodicalIF":4.9,"publicationDate":"2024-11-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142747415","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Application of inclined channels in the hydrodynamic classification of minerals by particle size – Extension to coarser separations","authors":"J.B. Starrett,&nbsp;K.P. Galvin","doi":"10.1016/j.mineng.2024.109114","DOIUrl":"10.1016/j.mineng.2024.109114","url":null,"abstract":"<div><div>A REFLUX™ Classifier was used to classify a silica feed (0–710 µm) based on particle size. Split Fluidisation was used to generate remarkably sharp separations involving solids throughputs of up to 92 t/m²/h. This work builds on the previous study by <span><span>Starrett and Galvin (2023)</span></span> but with a focus on coarser separations at higher throughputs. As the separation size increased, there was increasing misplacement of fine particles in excess of 75 µm into the coarse underflow stream. This problem was averted by halving the cross-sectional area of the lower section of the REFLUX™ Classifier. This change led to a doubling of the superficial fluid velocity in the lower section for a given set of flow rates, ensuring fine particles were unable to settle into the coarse underflow. In general, the separations performed in this study show complete closure of the partition curve at both the coarse and fine ends. It was also found that to deliver sharp separations it is essential to introduce sufficient water to the separator, per unit of solids transport to the overflow, especially for higher solids throughputs with coarser separations. Although the fluidisation rate can be used to control the separation size at finer separations (below 180 µm) and lower throughputs, ultimately the bias flux provides the basis for controlling the separation size at coarser sizes and higher throughputs.</div></div>","PeriodicalId":18594,"journal":{"name":"Minerals Engineering","volume":"222 ","pages":"Article 109114"},"PeriodicalIF":4.9,"publicationDate":"2024-11-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142747411","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Exploring the influence of surface roughness on the interface phenomenon between an air bubble and a glass bead: An experimental and theoretical investigation","authors":"Mianyan Yang,&nbsp;Zhijun Zhang","doi":"10.1016/j.mineng.2024.109126","DOIUrl":"10.1016/j.mineng.2024.109126","url":null,"abstract":"<div><div>The effect of surface roughness on the detachment between the bubbles and the glass beads (soda-lime) was comprehensively investigated. Glass beads with dimensions of −1.20 + 1.12 mm were acid etched to achieve varying degrees of surface roughness, followed by silanation reactions conducted for different immersion times. The characterization of surface roughness was conducted using a ContourGT-K 3D optical microscope. Measurements of receding contact angle, induction time and detachment force were conducted to assess the influence of surface roughness on bubble and glass bead attachment/detachment. It is observed that the etching surface of glass beads with uniform protrusions and depressions, the hydrophobic glass beads exhibited shorter induction time, larger contact angle and higher critical detachment force. However, the stability of aggregates of bubbles and hydrophilic glass beads was reduced, making them prone to detachment. Moreover, larger protrusions and depressions on hydrophobic glass bead surfaces with increasing etching time, resulted in an increase in induction time, a decrease in receding contact angle and critical detachment force. The stability of bubbles and hydrophilic glass bead aggregates remained unchanged.</div></div>","PeriodicalId":18594,"journal":{"name":"Minerals Engineering","volume":"222 ","pages":"Article 109126"},"PeriodicalIF":4.9,"publicationDate":"2024-11-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142747413","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}