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Correspondence of bubble size and frother partitioning in flotation

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Journal of Central South University 2014年第6期21卷 2383-2390页

作者：张炜 Jan E.Nesset James A.Finch Mining & Mineral Resources Division Department of Business AdministrationChinalco China Copper Corporation Limited Department of Mining and Materials Engineering McGill UniversityMontrealQCH3A 0C5Canada

The size of bubbles created in the flotation process is of great importance to the efficiency of the mineral separation ***,it is believed that frother transport between phases is perhaps the most important reason for the interactive nature of the phenomena occurring in the bulk and froth phases in flotation,as frother adsorbed in the surface of rising bubbles is removed from the bulk phase and then released into the froth as a fraction of the bubbles *** causes the increased concentration in the froth compared to the bulk concentration,named as frother *** reflects the adsorption of frother on bubbles and how to influence bubble size is not *** currently exists no such a topic aiming to link these two key *** fill this vacancy,the correspondence between bubble size and frother partitioning was *** size was measured by sampling-for-imaging(SFI)*** total organic carbon(TOC)analysis to measure the frother partitioning between froth and bulk phases was *** have shown,with no exceptions including four different frothers,higher frother concentration is in the bulk than in the *** results also show strong partitioning giving an increase in bubble size which implies there is a compelling relationship between these two,represented by CFroth/CBulk and *** CFroth/CBulkand D32 curves show similar exponential decay relationships as a function of added frother in the system,strongly suggesting that the frother concentration gradient between the bulk solution and the bubble interface is the driving force contributing to bubble size reduction.

关键词： flotation frother bubble size frother partitioning total organic carbon (TOC) analysis concentration gradient

Adsorption structures of frothers at gas–liquid interface using DFT method

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Journal of Central South University 2019年第3期26卷 536-549页

作者： ZHANG Yi-bing CHEN Jian-hua LI Yu-qiong ZHANG Pei-xin College of Resources Environment and Materials Guangxi University Guangxi Colleges and University Key Laboratory of Minerals Engineering College of Chemistry and Environmental Engineering Shenzhen University

Density functional theory (DFT) simulation was performed to investigate the adsorption mechanisms between frothers and gas–liquid interface. In water phase, the polar head group of the frother molecule was connected with water molecules by hydrogen bonding, while the non-polar group showed that hydrophobic property and water molecules around it were repelled away. The adsorption of water molecules on single frother molecule suggests that the complexes of α-terpineol-7H2O, MIBC-7H2O and DF200-13H2O reach their stable structure. The hydration shell affects both the polar head group and the non-polar group. The liquid film drainage rate of DF200 is the lowest, while α-terpineol and MIBC are almost the same. The adsorption layer of frother molecules adsorbed at the gas-liquid interface reveals that the α-terpineol molecules are more neatly arranged and better distributed. The DF200 molecules are arranged much more loosely than MIBC molecules. These results suggest that the α-terpineol molecule layer could better block the diffusion of gas through the liquid film than DF200 and MIBC. The simulation results indicate that the foam stability of α-terpineol is the best, followed by DF200 and MIBC.

关键词： frother water phase gas-liquid interface foaming DFT

A novel quantificational assessment method of frothers effect on bubble characteristics

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Journal of Central South University 2011年第6期18卷 1910-1916页

作者：胡岳华孟祥利孙伟 School of Mineral Processing and Bioengineering Central South University

A new visual method for quantitative measurement of frothers effect and flotation efficiency was presented. A self-designed electrolytic cell was chosen as the reaction environment with sodium chloride (NaCl) as the electrolyte. Constant current, supplied by a self-designed power supplier and fixed cathode and anode equipment, guaranteed the constant bubble volume per unit time. Even aperture of the cathode material guaranteed the original bubbles size to be uniform. Bubble generating equipment was connected with a microscopical camera. Statistic data collected by high speed charge-coupled device (CCD) and processed by software Sigmascan and Matlab could reflect bubble characteristics. The efficiency of dipropylene glycol monomethyl ether (DPM) and tripropylene glycol n-butyl ethel (TPnB) were measured at the same condition, and 2×10-4 mol/L and 5×10-2 mol/L were found to be the inflexions of bubble size changes.

关键词： frother bubble image processing data screening flotation efficiency

Flotation of carbonaceous copper shale-quartz mixture with poly(ethylene glycol) alkyl ethers

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Transactions of Nonferrous Metals Society of China 2015年第1期25卷 314-318页

作者： Przemyslaw B.KOWALCZUK Emilia ZALESKA Oliver DANCZAK Wroclaw University of Technology

The influence of different poly（ethylene glycol） alkyl ethers（CnH2n＋1O（C2H4O）mH, CnEm） on flotation of carbonaceous copper shale mixed with quartz as a gangue mineral was investigated. The results show that all of the ethers C4E1, C4E2, C4E3, C2E2, C6E2 investigated can be used for the flotation of carbonaceous copper shale. The best selectivity of separation in the flotation of the carbonaceous copper shale and quartz mixture is obtained with the C4E2 and C2E2 ethers. The obtained data can be used for developing separation of organic carbon present in carbonaceous shale at a rougher flotation stage on an industrial scale.

关键词： flotation frother selectivity shale quartz poly(ethylene glycol) alkyl ethers

Evaluation of effect of viscosity changes on bubble size in a mechanical flotation cell

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Transactions of Nonferrous Metals Society of China 2014年第9期24卷 2964-2968页

作者：张炜中铝中国铜业有限公司企业管理部矿产资源处北京100082 加拿大麦吉尔大学采矿与材料工程系

In operating flotation plants, the viscosity of the pulp can vary significantly. Consequently, the resulting impact on bubble size is of interest as many plants experience seasonal changes in water temperature, or particle size changes as ore hardness, mineralogy and throughput fluctuate. However, given its importance in flotation, there existed no mathematical relationship linking bubble size created in flotation machines to the key process variable of fluid viscosity. In this study, a program of investigation to develop such a model was utilizing a pilot-scale mechanical flotation machine, to investigate the effect of water viscosity due to temperature on bubble size distribution. The bubble sizes were determined using a specific bubble viewer and imaging technology. The temperature itself was varied as a method for introducing significant viscosity change. The viscosity-temperature effect introduced a correspondingly significant change in the water viscosity（1619 to 641 μPa·s）. It is suggested that a considerably stronger relationship may exist, yielding D32 versus（μ/μ20）0.776, and hence viscosity becomes an important design consideration for plants operating where pulp temperature fluctuations, very small particles or high solid fractions are present.

关键词： flotation bubble size viscosity surface tension frother

A novel approach to prevent bubble coalescence during measurement of bubble size in flotation

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Journal of Central South University 2014年第1期21卷 338-343页

作者：张炜 Jan E.Nesset James A.Finch Mining and Mineral Resources Division Department of Business AdministrationChinalco China Copper Corporation Limited Department of Mining and Materials Engineering McGill University

Effect of frothers in preventing bubble coalescence during flotation of minerals has long been *** evaluate the performance of a frother,an apparatus to measure the bubble size is a basic *** Bubble Size Analyzer(MBSA) or bubble viewer that has been developed and completed by McGill University's Mineral Processing Group during the last decade is a unique instrument to serve this *** parameters which are thought to influence the bubble size measurements by McGill bubble viewer include water quality and frother concentration in the *** show that there is no difference in Sauter mean(D32) when tap or de-ionized water was used instead of process ***,the frother concentration,in this research DowFroth 250(DF250),inside the chamber exhibited a pronounced effect on bubble *** concentration below a certain point can not prevent coalescence inside the chamber and therefore caution must be taken in plant *** was also noted that the frother concentration which has been so far practiced in plant measurements(CCC75-CCC95) is high enough to prevent coalescence with the bubble viewer.

关键词： flotation frother bubble size bubble coalescence

Bubble size as a function of some situational variables in mechanical flotation machines

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Journal of Central South University 2014年第2期21卷 720-727页

The specific results of the work investigating the effect of gas density and water temperature on bubble size were *** were surrogate variables designed to investigate the effect of viscosity(varying water temperature) and altitude(varying gas density).The results show that there is a measurable but relatively small effect of gas density on bubble *** D32 is revealed to increase proportionally as(ρ0/ρg)*** projected impact on flotation kinetics at 4500 m versus sea level is small,of the order of 0.5% recovery loss for a bank of eight flotation *** effect of water temperature(4-40 °C) on bubble size is more significant than gas *** relationship correlates with water viscosity values quite closely.A finding that D32 increases proportionally as(μ/μ20)0.776 highlights the importance of accounting for viscosity effects if,for example,large process temperature fluctuations or deviation from design/test conditions are expected.

关键词： flotation frother bubble size viscosity altitude

Flotation performance analysis on coal washery rejects

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Energy Geoscience 2021年第3期2卷 211-217页

作者： P.S.Kumar O.Sivrikaya S.Pradhan P.C.Nagannor Department of Mineral Processing VSKUPG CentreNandihalliKarnatakaIndia Adana Alparslan Türkes¸Science and Technology University Turkey Department of Mineral Engineering Government College of EngineeringKeonjharIndia

The coal washery rejects cause major environmental problems in various parts of the *** 1 Mt of coal rejects discarded as waste,is accumulated per annum in India,during washing or cleaning of raw *** coal,especially washery rejects,has posed a major challenge to the recovery of fine *** flotation is a better choice for processing coal washery *** this study,flotation studies are attempted on the coal slurry received from Sudamdih coal washery,Jharkhand,India.A statistical design package(Minitab V17)was used to study the effect of process variables like collector and frother dosages on the *** equations for froth height,froth density,recovery and ash content of clean coal were *** coefficient of correlation(R2)values between the experimental and the predicted values of the flotation responses was found to be greater than 0.98 for all the *** coal product was analyzed for recovery,froth height,and ash content by varying pulp *** show that the coal slurry sample could be evaluated with acceptable recovery via *** coal with an ash content of 17.2%is obtained with a 70%recovery from 35.5%*** cleaned coal can be used in powder coal-consuming industries.

关键词： Coal Flotation Collector frother Ash removal

2<sup>k</sup>Factorial Experiments on Factors that Influence the Recovery of Gold during the Upgrade of Ilesha-Itagunmodi Gold Ore through Froth Flotation

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Journal of Minerals and Materials Characterization and Engineering 2014年第1期2卷 32-39页

作者： Kayode Emmanuel Oluwabunmi Abraham Adewale Adeleke Adelana Razak Adetunji Samson Olaitan Jeje Abiodun Ayodeji Abioye Olusola Adedayo Adesina Fatai Afolabi Ayeni Folahan Peter Ibitoye Department of Chemical Engineering Landmark University Omu-Aran Nigeria Materials Science and Engineering Obafemi Awolowo University (O.A.U.) Ile-Ife Nigeria Prototype Engineering Development Institute (PEDI) Ilesa Nigeria Prototype Engineering Development Institute (PEDI) Ilesa Nigeria Materials Science and Engineering Obafemi Awolowo University (O.A.U.) Ile-Ife Nigeria

A low-grade gold ore from Ilesha-Itagunmodi, south western Nigeria was panned, dried and ball-milled before sieving into fractions. The morphological, mineralogical and chemical composition was studied by optical micro-scopy (Reflected and Transmission), X-ray diffraction (XRD) and Energy Dispersive X-ray fluorescence (XRF), respectively. The sieved fractions were subjected to chemical analysis (AAS). The +106 μm sieve had the highest concentration of the mineral and was then selected for the upgrade through froth flotation using standard reagents. In this paper a report on a 2k factorial experiment that provides an understanding of the impact of operational variables on the quantity of gold mineral obtained from the ore during froth flotation is presented. Analysis results showed that Ilesha-Itagunmodi gold ore is non-refractory with fine grain particles, amenable to froth flotation and contained about 20 other associated minerals, gold had a concentration of about 0.0024%. A com-bination of P-Xanthate and amine glycol collectors at a pH of 9.2 only produced a considerable increase in gold yield. This translated to about 87.13% increase in recovery of gold from the ore. Analysis of variance (ANOVA) was carried out and the model equation obtained was subsequently optimised to obtain a model equation that could be used in predicting the recoverable quantity of gold, indicating that F11,1-values for Collector concentration, frother concentration, pH and Conditioning time were 156.86, 6.96, 43.81, and 56.77 respectively. A model with an F value of 88.41 was obtained which indicated that the model was significant. The model equation obtained was subsequently optimised to be able to predict the recoverable quantity of gold. A “Pred R-Squared” value of 0.9365 (93.65%) was also obtained and is in reasonable agreement with the “Adj R-Squared” value of 0.9534 (95.34%). It was established that Ilesha placer gold ore is amenable to froth flotation using standard reagents.

关键词： Factorial Froth Flotation Collector frother Concentration Surface Graph Conditioning Time