高气泡表面积通量浮选柱浮选硫化铜矿的研究

高气泡表面积通量浮选柱可以在较高表观充气速率情况下,有效地提高气泡表面积通量,避免因气泡携带能力不足导致的回收率损失。高气泡表面积通量浮选柱和机械搅拌浮选机浮选浸染型矽卡岩铜矿石的对比试验表明。采用铜硫混合浮选再铜硫分离流程或优先浮铜流程,高气泡表面积通量浮选柱在减少精选作业次数的情况下,浮选指标明显优于机械搅拌浮选机,提高的幅度与流程有关。     

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。     

浮选柱中气体分散与废纸脱墨研究

本文对直径为4英寸和20英寸浮选柱在废纸再生脱墨中，4个气体分散参数进行了研究。充气率(eg)和截面气体速度(Jg)为在线测定，气泡尺寸(db)用通量分析法估计，根据气泡尺寸能计算出泡沫表面积通量(Sb)。在接近零泡沫厚度条件下，测定了油墨在浮选柱中滞留时间(受底流流量所控制)与油墨回收率之间的函数关系。根据混合模型，借助回收率一浮选时间数据，估算了捕收区的浮选速率常数(ke)。与选矿中的浮选研究结果类似，浮选速率常数与Jg和db无关，但与eg和Sb呈线性相关。     

一种浮选机动力学性能测量系统的研制

浮选表观充气速率、气泡直径、气泡表面积通量是最为重要的评价浮选机动力学性能的参数。目前国内外用于测算这三个参数的设备或仪器存在功能单一、操作复杂、测量精度差、自动化程度不高等问题,给科研工作者的研究带来较大困难。介绍了一种自动在线检测与计算表观充气速率、气泡直径、气泡表面积通量三个浮选机动力学性能测量系统,可以为浮选机动力学基础理论的研究提供实时准确的数据,为在线优化浮选流程、诊断叶轮磨损、预测浮选指标等上层技术的研究和应用提供支撑。     

680m~3浮选机工业化应用过程中的动力学性能测试与分析

680m~3浮选机投入生产试运行已一年有余,表现出卓越的设备稳定性和分选性。本文从浮选流体动力学角度出发,对680m~3浮选机在带矿运行过程中的充气性能、矿浆循环悬浮性能和气泡大小及其负载性能进行了测试分析。结果表明,680m~3浮选机充气量可以达到1.1m~3/(m~2·min)以上,能够满足一般硫化矿大气量的生产需求,空气分散度在7以上,平均气含率约7%;不同深度浮选槽内矿浆浓度和粒级分布较为均匀,无明显分层现象。气泡表面积通量可达39.20s-1,随着气泡的上浮,气泡负载呈现上升趋势,最高可达3.37g/L。优越的浮选流体动力学特性充分地保障了680m3浮选机良好的分选效果。     

KYF型浮选机气泡特征参数分析与探讨—KYF浮选机流场测试与仿真研究(五)

浮选机内气泡特征参数和流动规律的研究一直是浮选机研究的重点和难点。本文利用电导探针法和CFD数值方法研究了浮选机内气泡特征参数及其分布特性。通过电导探针法获取了浮选机内气泡直径、速度和气含率等气泡特征参数。利用CFD数值方法揭示了浮选机内气含率的分布特征,预测结果同试验观察一致。并进一步研究了浮选机关键运转参数对气含率分布的影响规律。试验结果表明,CFD预测的气含率同试验测试结果吻合。     

KYF型浮选机内气泡特征参数分析与探讨——KYF浮选机流场测试与仿真研究(五)

浮选机内气泡特征参数和流动规律的研究一直是浮选机研究的重点和难点.本文利用电导探针法和CFD数值方法研究了浮选机内气泡特征参数及其分布特性.通过电导探针法获取了浮选机内气泡直径、速度和气含率等气泡特征参数.利用CFD数值方法揭示了浮选机内气含率的分布特征,预测结果同试验观察一致.并进一步研究了浮选机关键运转参数对气含率分布的影响规律.试验结果表明,CFD预测的气含率同试验测试结果吻合.     

高气泡表面积通量浮选柱浮选硫化铜矿参数的研究

通过浮选硫化铜矿的研究，检验高气泡表面积通量浮选柱的浮选性能，优化主要结构参数和操作参数。研究表明，高气泡表面积通量浮选柱采用多段相互独立的发泡器，可以在表观充气速率较高的情况下，不增大气泡直径，而增加气泡数量，从而有效地增大气泡表面积通量，并且减少了气泡在浮升过程中兼并的可能性，避免了疏水颗粒的脱落和因气泡携带能力不足导致的回收率损失，对分选效率的提高有着十分显著的效果。高气泡表面积通量浮选柱浮选硫化铜矿，在精矿品位下降不大的情况下，回收率可提高10个百分点以上。     

浮选气泡表面积通量多元耦合性分析与控制策略研究

气泡表面积通量不仅是评价浮选动力学的关键参数,也是浮选设备大型化研究设计的基础。针对目前国内、外对浮选气泡表面积通量的研究相对欠缺,本文提出了针对气泡表面积通量的多元耦合规律性分析以及在线过程调控的思路。综合数字图像处理、数据挖掘技术和案例推理算法,建立一个关于浮选气泡表面积通量的数学控制模型。本文对气泡表面积通量在工业现场的生产应用和科学研究提供了理论基础,对于提高浮选分选效率、优化浮选设备的设计都有重要意义。     

钼粗扫选作业KYF-320浮选机浮选动力学研究

对洛阳栾川钼业集团股份有限公司选矿三公司粗扫选作业技术改造采用的KYF-320浮选机空气分散度、气含率、气泡负载率、悬浮能力等关键浮选动力学参数进行了测试。测试结果表明:浮选机空气分散度均在2以上,分散效果良好;单台浮选机气含率分布均匀,最大气含率达到16.0%,能够保证矿物颗粒与气泡间的碰撞概率;气泡负载率变化幅度较小,证实在矿化气泡上升过程中矿物颗粒无明显脱附显现;近泡沫层区域矿物颗粒有一定分层现象,有利于目的矿物和脉石分离,KYF-320浮选机浮选动力学特征能够满足该项目钼浮选工艺要求。     

Review of hydrodynamics and gas dispersion in flotation cells on South African platinum concentrators

Hydrodynamic and gas dispersion parameters, obtained from industrial flotation cells on South African Platinum concentrators, are reviewed in this paper. Hydrodynamic results show that power intensities are slightly higher than those typically observed in industrial flotation cells while impeller tip speeds and Froude numbers are within the range found in industrial cells. Gas dispersion results show that air flow rates, air flow numbers and air flow velocities vary significantly from cell to cell but are within the range typically found in industrial flotation cells. Gas dispersion results also show reasonably broad variations in bubble size, gas holdup and superficial gas velocity, although bubble surface area fluxes are shown to lie within a fairly narrow range of 50–70/s.     

160m3浮选机浮选动力学研究

对160m3浮选机进行了浮选动力学研究,主要测量了充气量、空气分散度、转速、功率、气泡大小、含气率等有关参数,并分析了充气量与空气分散度、功率、气泡大小、空气保有量的关系,最后确定了最佳转速。     

Measuring gas dispersion parameters: Selection of sampling points

Bubble surface area flux has proven to be a key operational variable in flotation machines not only for diagnosis but also for optimization purposes. It is calculated as a combination of two gas dispersion properties, superficial gas velocity and bubble Sauter mean diameter. Since gas is not necessarily distributed evenly over the cross sectional area of a cell the sampling point where gas dispersion properties are measured must be carefully selected. This article illustrates that a radial parabolic gas velocity profile exists in mechanical cells, in some cases with significant variation in gas velocity as a function of radial distance from the center. An optimal sampling location for single point gas dispersion measurements in mechanical flotation machines is proposed.     

On the relationship between flotation rate and bubble surface area flux

Flotation scale-up has been a major difficulty and is becoming more so as the flotation machines continue to grow in size. It has been proposed by Gorain and his coworkers that the flotation rate constant has a linear relationship with the bubble surface area flux.This paper discusses that claim using the data presented to validate that claim. It can be shown that the measurement and computation of superficial gas velocity, and partially also the bubble size may be biased in some conditions. This makes the bubble surface area flux behave such that the final outcome is in doubt. The validation does not address the different particle sizes at all.     

Indirect estimation of bubble size using visual techniques and superficial gas rate

In this paper, an indirect method for determining the Sauter mean diameter of a bubble population is presented. The technique relies on the estimation of the percent area occupied by bubbles in a 2D image as well as on the superficial gas rate. The percent area was defined as the quotient between the black pixels (bubble representation) divided by the total pixels in a binary image. A linear model to describe the Sauter diameter as a function of the percent area and the superficial gas rate was proposed. The regressions showed a fairly good predictive capacity in laboratory and industrial flotation machines under bubbly regime, which makes the proposed methodology a promising tool for monitoring and controlling gas dispersion in real time.     

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.     

Bubble spargers in column flotation: Adaptation to precipitate flotation

The limiting factor for metal-organic precipitate flotation in a column is the level of aggregate stability under the turbulence created by the rising bubbles. The hydrodynamic conditions in a 75 mm diameter pilot column were optimised by using different bubble spargers (Microcel, Flotaire, Imox) and by varying the gas flow rate into the bubble sparger, feed flow rate in the column, type and concentration of frother and recirculating pump flow rate. With the bubble spargers used, the average bubble diameter ranges from 0.30 and 1.10 mm, with up to 25% gas hold-up. The parameters influencing average bubble diameter are the superficial gas velocity and the recirculating pump flow rate. For optimal concentrations (10 to 20 mg/1), the type of frother has a negligible role.Strong interaction occurs between superficial gas and feed velocities and recirculating pump flow rate for bubble size control. The optimum operating conditions must accordingly be maintained to prevent carryover of small bubbles into the recirculating pump or the purified solution. An example of the Mo precipitate flotation confirms the assumption made for the effect of bubble size and dissipation energy on the separation results. reserved.     

Flotation in a novel oscillatory baffled column

This paper presents an evaluation of an oscillatory baffled column (OBC) as a novel flotation device. The cell is based on a standard column design but employs a novel agitation mechanism where a series of baffle plates are oscillated sinusoidally through the fluid. This type of agitation has been shown to produce a more evenly distributed shear rate in the cell and allows the effect of agitation on particle–bubble contacting to be decoupled from gas dispersion effects. The column was first characterised in terms of mixing and gas dispersion, before being flotation tested using a quartz-amine system. Results indicated that the OBC was able to improve the flotation rate constant by up to 60% for fine particles (<30 μm) and by between 30% and 40% for coarser particles, relative to a standard flotation column. Interestingly, optimal flotation performance was obtained at power intensities orders of magnitude lower than those found in similar studies in stirred systems. This is believed to arise from the even distribution of shear in the OBC together with the oscillatory motion of the fluid in the cell. This oscillatory motion does not contribute to the average power intensity in the fluid and therefore results in more fluid motion per unit energy than would be obtained in a conventional stirred system. The OBC was therefore able to significantly improve flotation rates at power intensities orders of magnitude lower than those found in conventional cells.