Air bubble movement in pulsating liquid

The measurement data on the air bubble movement in a pulsating liquid are considered in order to define the mechanism of oscillatory flotation more exactly. The dependence of absolute and relative velocities of bubble oscillations on the parameters of liquid pulsation is established. __________ Translated from Fiziko-Tekhnicheskie Problemy Razrabotki Poleznykh Iskopaemykh No. 5, pp. 100–106, September–October, 2006.     

Interaction of a “gas-liquid” phase interface with a mineral particle

The interaction of a mineral particle with the surface of a bubble during froth flotation is studied. Results are presented from an analysis of the equation of motion of a particle fixed at the interface. It is shown that preservation of the “particle-bubble” aggregate depends on the frequencies of natural vibrations of the bubble and the particle and the properties of the surface of the mineral. Institute of Mining, Siberian Branch, Russian Academy of Sciences, Novosibirks. Translated from Fiziko-Tekhnicheskie Problemy Razrabotki Poleznykh Iskopaemykh, No. 4, pp. 115–120, July–August, 1999.     

Flotation kinetics equations and transfer functions for flotation machines taking account of the effect of the froth layer

Conclusions Flotation kinetics equations and transfer functions have been obtained for a two-phase flotation model. It has been demonstrated that specific flotation rate depends on concentration of minerals being floated in the froth layer. Sverdlovsk. Translated from Fiziko-Tekhnicheskie Problemy Razrabotki poleznykh Iskopaemykh, No. 4, pp. 107–111, July–August, 1984.     

Physically sorbed collectors in froth flotation and their activity. Part I

It is demonstrated that the basic factor, identifying the capability to form a flotation complex, is the availability of a reagent sorbed physically on a particle surface and promoting the thinning-down of water interlayer between a mineral particle and a bubble at final stages of their approach. The numerical evaluation of the effect of physically sorbed collector on variations in the velocity of water discharge from an interlayer, partitioning a mineral particle and a gas bubble at the moment of their meeting is given. __________ Translated from Fiziko-Tekhnicheskie Problemy Razrabotki Poleznykh Iskopaemykh, No. 6, pp. 118–125, November–December, 2008.     

Experimental-analytical methods of the investigating the effect of complexing reagents on platinum flotation

The paper considers the studies into the hydrophobic properties of platinum and platinum arsenide, sperrylite, in the solution with added complexing reagents by using the method of measuring the force of the air bubble abstraction from the mineral surface. The effect of these complexing reagents on the chemical properties of sperrylite and pyrrhotine is analyzed. A new-developed procedure for treatment of pyrrhotine by chloroplatinic acid is presented, and the comparative flotation of natural pyrrhotine and platinum-pretreated pyrrhotine with the complexing reagents is described. The collecting properties of diisobutyl dithiophosphinate for platinum are determined, and the use of this reagent as an additional collector for platinum-group metals is confirmed in the course of the experimental flotation of platinum-bearing copper-nickel ore samples. __________ Translated from Fiziko-Tekhnicheskie Problemy Razrabotki Poleznykh Iskopaemykh, No. 3, pp. 68–75, May–June, 2008.     

气泡负载测量装置的创新及应用

对比分析了现有气泡负载测量装置的应用及存在的不足,介绍了一种改进型的气泡负载测量装置及创新测量方法,能够实现长时间连续稳定测量取样,且干扰少,精度高。将该装置和方法应用在工业浮选设备的测试中,对江西某一选矿厂的两个平行选硫生产线的粗、扫选作业进行了气泡负载测量及其对比分析,一期选矿厂粗、扫选作业浮选机内的气泡负载率在最浅处仅为9.99g/L和2.64g/L,而二期选矿厂达到了16.25g/L和8.47g/L。同时,利用该装置,首次对浮选槽近液面区域内矿化气泡运输过程中的负载变化规律进行了探究,结果表明,随着气泡的上升,粗选浮选槽内气泡负载量在近液面区呈现上升趋势,而扫选浮选槽内气泡负载量在近液面区呈现相反的下降趋势,这一规律同时也在另一个生产系列得到验证。气泡负载量的差异和变化规律揭示了浮选槽内气泡的矿化过程,可为选矿厂工艺调整及浮选槽性能的改进提供参考依据。     

Stabilization of bubble size in a flotation cell

Conclusions  

On regularities observed in formation of liquid phase composition in flotation sulfide pulp

It is shown that modifiers decrease oxidation of pyrite following the line: cyanide > thiosulphate > sulfite > sulfide > dioxide. Action of the modifiers shows itself weaker for other sulfide minerals. The mode of selective flotation of cooper-zinc, copper-pyritic and other products has been developed with allowance for this fact. Iron powder and ferrous iron, as fine reducing agents, advantage to saving the natural surface of a sulfide mineral and improving the flotation selectivity. Decrease in the concentration of copper in liquid phase, that activates sphalerite, and stabilization of anionic composition depend on the mode of pulp conditioning by grinding and flotation, based on the use of various modifiers, their feeding points and pH of the medium. __________ Translated from Fiziko-Tekhnicheskie Problemy Razrabotki Poleznykh Iskopaemykh, No. 1, pp. 108–119, January–February, 2007.     

CFD modelling of bubble–particle attachments in flotation cells

In recent years, computational fluid dynamic (CFD) modelling of mechanically stirred flotation cells has been used to study the complexity of the flow within the cells. In CFD modelling, the flotation cell is discretized into individual finite volumes where local values of flow properties are calculated. The flotation effect is studied as three sub-processes including collision, attachment and detachment. In the present work, these sub-processes are modelled in a laboratory flotation cell. The flotation kinetics involving a population balance for particles in a semi-batch process has been developed.From turbulent collision models, the local rates of bubble–particle encounters have been estimated from the local turbulent velocities. The probabilities of collision, adhesion and stabilization have been calculated at each location in the flotation cell. The net rate of attachment, after accounting for detachments, has been used in the kinetic model involving transient CFD simulations with removal of bubble–particle aggregates to the froth layer.Comparison of the predicted fraction of particles remaining in the cell and the fraction of free particles to the total number of particles remaining in the cell indicates that the particle recovery rate to the pulp–froth interface is much slower than the net attachment rates. For the case studied, the results indicate that the bubbles are loaded with particles quite quickly, and that the bubble surface area flux is the limiting factor in the recovery rate at the froth interface. This explains why the relationship between flotation rate and bubble surface area flux is generally used as a criterion for designing flotation cells. The predicted flotation rate constants also indicate that fine and large particles do not float as well as intermediate sized particles of 120–240 μm range. This is consistent with the flotation recovery generally observed in flotation practice. The magnitude of the flotation rate constants obtained by CFD modelling indicates that transport rates of the bubble–particle aggregates to the froth layer contribute quite significantly to the overall flotation rate and this is likely to be the case especially in plant-scale equipment.     

浮选柱强化细粒分选的研究

为改善浮选柱对细粒矿物的浮选效果 ,根据浮选矿浆流体动力学及矿粒与矿粒之间、矿粒与气泡之间的相互作用机理 ,在强化细粒疏水性矿物与气泡之间作用的方法和减少细粒脉石矿物夹杂的方法两个方面做了深入分析 ,得出了细粒浮选柱结构设计的基本思想 ,为今后有效细粒浮选柱的结构设计提供了理论基础。     

Evaluation of the selective detachment process in flotation froth

The improved selectivity between particles of varying degrees of hydrophobicity in flotation froths has been well documented in literature, especially in the deep froths utilized in flotation columns. The phenomenon is believed to be due to the selective detachment process whereby the least hydrophobic particles are released from the bubble surface upon bubble coalescence. To quantify the selective detachment process, column flotation experiments were performed under various operating conditions that provided varying amounts of reflux between the froth and collection zones. Entrainment was eliminated by the use of relatively coarse 250 × 75 micron material. The flotation column incorporated the ability to provide instantaneous stoppage of the process streams and separation between the collection and froth zones after ensuring steady-state operation of the column. The samples collected from the two zones and process streams were evaluated to quantify the flotation rate distribution of the particles comprising each sample. The flotation rate was used as an indicator of the degree of hydrophobicity and thus a relative measure of the binding force between the particle and bubble in the froth zone. The flotation rate data was used as input into well known flotation models to obtain the froth zone recovery rate and the quantity of material that refluxes between the collection and froth zones.     

浮选体系中气泡运动特性研究进展

在浮选体系中,气泡的运动特性直接影响着矿物浮选的选别效果,因此,研究气泡的运动特性,对于优化浮选工艺与改善浮选效果有着重要意义。本文首先简述了浮选中常见的气泡生成方式,主要有机械搅拌发泡、气泡发生器发泡、电解发泡及超声波发泡四种方式;气泡参数中介绍了气泡形态特征参数、运动特征参数和分布特征参数的含义和计算公式;然后重点阐述了浮选中起泡剂、捕收剂、抑制剂、浮选机叶轮参数、浮选柱气泡发生器及充气量对气泡参数的影响;归纳了纳米气泡在微细粒矿物浮选中的应用;最后指出,完善气泡测量方法、侧重于气泡在实际浮选环境中的运动特性研究以及研发新型纳米气泡生成设备将是未来的发展方向。     

Thermodynamic and flotation analysis of influence exerted by chromate ions on separation of galena and chaclopyrite in alkaline media

The thermodynamic studies into the state of surface of galena and chalcopyrite in the presence of chromate ions and xanthate ions have been carried out along with the potentiometric measurements and flotation analysis. In the alkaline media, chromate ions are potential-determining for galena and are not such for chalcopyrite in a wide range of chromate ion concentrations. The qualitative composition of the sorption layer of the collecting and depressing agents on galena and chalcopyrite surfaces will depend on pH and redox potential of the fluid phase, and on the concentration of ions of the depressing and collecting agents. The flotation separation of galena and chalcopyrite in the alkaline media is feasible with the use of chromate ions as the depressing agents for galena. __________ Translated from Fiziko-Tekhnicheskie Problemy Razrabotki Poleznykh Iskopaemykh, No. 6, pp. 118–128, November–December, 2007.     

气泡、油泡和活性油质气泡在浮选中的应用和机理探讨

浮选是高效回收矿产资源应用最广泛的技术方法。气泡作为浮选载体在浮选过程中有着举足轻重的作用。以气泡-油泡-活性油质气泡为线索,对比了传统气泡与改性后油泡(气泡表层包裹一薄层油性捕收剂)、活性油质气泡(气泡表层包裹一薄层含有捕收剂的中性油)的浮选特性。通过浮选动力学分析了气泡与油泡、活性油质气泡浮选的区别,传统气泡浮选与改性后的油泡浮选均为2步反应,而活性油质气泡实现了1步浮选,大大降低了气泡与矿物颗粒间的黏附功,提高了浮选效率。从油-水界面表面活性剂解离度这个角度分析了活性油质气泡的表面性质,指出活性油质气泡的表面电性由表层中性油中添加的捕收剂和p H决定。通过DLVO理论计算了不同气泡与矿物颗粒间的相互作用能,从理论上解释了活性油质气泡浮选指标更好的原因。活性油质气泡在选矿中的成功应用表明,活性油质气泡与矿物表面的作用均强于传统气泡与矿物表面的作用,即活性油质气泡对矿物具有更强的捕收能力,相较于气泡和油泡的浮选,活性油质气泡浮选有利于提高浮选效率,降低捕收剂用量。活性油质气泡作为浮选载体从气泡这一特殊视觉为浮选行业开辟了一个崭新的研究领域。     

高气泡表面积通量充气器气泡特征参数试验研究

充气器生成气泡的特征参数是影响气泡表面积通量的关键因素。利用电导探针法和拍照测径法获取了充气器产生气泡的直径、速度及其分布特征。利用CCD高速相机获取了充气器的气泡分散特征。结合浮选柱的清水试验研究,分析了充气器喷嘴直径和充气压力两个关键参数对气泡特征参数影响。研究表明,KYZ浮选柱充气器能形成高气泡表面积通量的柱内分选环境。工业应用表明,KYZ浮选柱高气泡表面积通量充气器能够实现优异的分选性能。     

Physically absorbable reagents-collectors in elementary flotation

Based on the reviewed researches held at the Institute of Mining, Siberian Branch, Russian Academy of Sciences, the effect of physically absorbable reagents-collectors on formation of a flotation complex and its stability in turbulent pulp flows in flotation machines of basic types is considered. The basic requirements for physically absorbable reagents-collectors at different flotation stages are established. __________ Translated from Fiziko-Tekhnicheskie Problemy Razrabotki Poleznykh Iskopaemykh, No. 5, pp. 86–95, September–October, 2007.     

Scientific grounds for high-performance agent modes in platiniferous sulfide mineral flotation from rebellious ores

The author substantiates the choice of new selective agents PTTC, HPEDETC, and Hostaflot M-91 to float platiniferous sulfide minerals from rebellious ores. The study agent modes imply the use of PTTC, being a component of modified xanthate and providing 6–7% increase in recovery of copper, nickel, and PGM in flotation of the low-sulfide platiniferous copper-nickel ore from the Fedorovo-Pansky deposit. The substitution of HPEDETC and Hostaflot M-91 for xanthate makes it possible to increase recovery of platinum by 5.7–13%, palladium by 4–9% and 2–4 times the noble metal content in the flotation concentrate.     

The empirical prediction of bubble surface area flux in mechanical flotation cells from cell design and operating data

In the operation of mechanical flotation cells, the dispersion of gas into fine bubbles may be expressed by three indicators : bubble size, gas holdup and superficial gas velocity. Taken together, these properties determine the bubble surface area flux (S_b) in the cell, which has been found to have a strong correlation with the flotation rate constant (k). Previous work by the authors has indicated that it is possible to predict the value of k for a known ore in a cell from a knowledge of the bubble surface area flux generated in that cell.In order to make good use of this finding, an empirical model has been developed to predict S_b in mechanical flotation cells, using data from extensive pilot industrial scale test programs. The model is able to predict Sb from cell operating conditions, impeller design and feed properties. The model has been validated for different types and cell sizes, impeller types and ore types, in different independent investigations carried out at several concentrators in Australia and South Africa.This paper outlines the development of the model, the parameter estimation, and the validation using a number of additional data sets.     

Theoretical basis for optimal collector concentrations and pulp pH values during flotation of sulfide-free minerals

A hypothesis that associates optimal conditions of mineral flotation with a zero charge of their surface is put forward. This hypothesis serves as a basis for a methodology to obtain and verify quantitative physical-chemical models for a minimal necessary concentration of a collector during flotation of sulfide-free minerals. These models may be of use for upgrading engineering processes of flotation and as a job for the concentration plant automation systems. __________ Translated from Fiziko-Tekhnicheskie Problemy Razrabotki Poleznykh Iskopaemykh, No. 2, pp. 89–99, March–April, 2006.     

浮选微泡调控及其作用机制的研究进展

气泡作为浮选过程的载体,其特征对浮选效率有显著影响,气泡特征调控是强化浮选过程的有效手段,近年来,微泡浮选引起广泛的关注。本文从微泡生成、气泡特征调控及矿化机制等方面总结了微泡浮选的研究进展。介绍了射流发泡、微孔介质发泡、溶气发泡、超声发泡和电解发泡的发泡原理及应用。从表面活性剂、电解质和能量输入角度分析了微泡直径的调控机制,并基于气泡形态和上升速度方面探讨了微泡运动特性的调控机制;从颗粒与气泡的碰撞、粘附和脱附过程角度全面分析了微泡与颗粒的作用机理。最后对浮选微泡调控及其作用机制的未来发展趋势进行展望。