高强度调浆对微细粒磷灰石浮选效果的影响研究

为了提高微细粒磷灰石的浮选指标,需要对入浮矿浆进行高强度调浆处理。本文以承德某地的斜板浓密溢流为研究对象,展开高强度调浆工艺条件试验。以实验室30L规格的高强度调浆机和工业上2m直径的高强度调浆机为研究手段,对调浆时间、调浆转速等展开条件试验。30L调浆机结果表明最佳的浮选时间为6分钟,最佳的线速度为8.35m/s,和普通改质机叶轮和直桨叶轮相比,新型叶轮的调浆效果更好,并且能耗较低。2m高强度调浆机的工业试验表明,150rpm是最佳的转速。并且和普通调浆机相比,在相同产率（粗选产率为5%~10%）下磷灰石的回收率提高了约10%,可见高强度调浆机能显著改善细粒磷灰石的浮选环境。清水条件高速摄像和浊度测试结果表明,高强度调浆机叶轮和普通搅拌槽叶轮相比,对油滴的分散效果更显著,搅拌后形成的乳浊液体系更为稳定。     

Estimation of flotation kinetic parameters by considering interactions of the operating variables

In this study, the classical first-order kinetic model was combined with a properly built statistical model based on a factorial experimental design, in order to accurately predict the rougher flotation efficiency for various flotation conditions. A three-level, three-factor experimental design was used to develop a statistical model to predict each of the kinetic model parameters as a function of the air flow rate, the feed grade and the froth thickness (or the pulp level). The statistical evaluation of the experimental results indicated that the ultimate recovery, the rate constant and time correction factor are not constant but each of these kinetic model parameters can be defined as a function of the variables considered. Furthermore, the rate of change in the kinetic parameters due to the feed grade fluctuation and their effects on the metallurgical performance can accurately be predicted by using the models developed. Thus, in order to reduce the detrimental effect of the feed grade fluctuations on the metallurgical performance, the operating variables of the flotation can be manipulated to obtain the desired concentrate grade. In addition, predictions with an error of less than 3.3% indicated that the versatility and viability of the classical first-order kinetic model could be improved by using the models developed.     

浮选柱操作参数对粗精煤产率的影响

为了解浮选柱操作参数(矿浆浓度、药剂用量、药剂种类)对细煤泥中粗精煤(0.25⁰.5 mm粒级)产率的影响程度,以矿浆浓度和起泡剂种类为研究对象,通过单因素试验和正交试验对其进行研究。试验结果表明:矿浆浓度与粗精煤产率成一定的线性相关关系,起泡剂种类对粗精煤产率的影响较显著;矿浆浓度与不同起泡剂的联合作用对粗精煤产率没有显著影响。实际生产中,应根据具体需要选择入浮矿浆浓度和起泡剂种类。     

Optimization of operating parameters for coarse sphalerite flotation in the HydroFloat fluidised-bed separator

Increasing the upper size limit of coarse particle flotation has been a long-standing challenge in the minerals processing industry. The HydroFloat separator, an air-assisted fluidised-bed separator, has been used in this study to float 250–1180 μm sphalerite particles in batch flotation tests and compared to results achieved utilizing a laboratory-scale conventional Denver cell. The quiescent environment within the HydroFloat cell significantly reduces the turbulent energy dissipation within the collection zone, hence decreasing the detachment of particles from bubbles during flotation. Three operating parameters including bed-level, superficial water and gas rates have been studied, and their effect on the flotation of coarse sphalerite particles is reported. It is shown that coarse sphalerite recovery increases with increasing bed-level, superficial water and gas flow rates. However, there are thresholds for each operating parameter above which recovery starts to decrease. A comparison of recovery with a conventional Denver flotation cell indicates that the HydroFloat separator vastly outperforms the conventional flotation machine for the very coarse particles (+425 μm), and this is mainly attributable to the absence of turbulence and the minimization of a froth zone, both of which are detrimental to coarse particle flotation.     

KYZ浮选柱操作参数对铜浮选效率影响的研究

对秘鲁某大型铜选矿厂的铜精选作业中KYZ浮选柱的操作参数进行探索性条件试验。在不影响选厂正常生产的前提下,以充气量、泡沫层厚度和喷淋水量三个操作参数为变量条件,对比不同条件下浮选柱的选别效果,找到了与工艺流程相适应的操作参数范围。进一步得出规律,浮选柱充气量越大则回收率越高而铜品位相对降低;喷淋水的添加对浮选柱精矿中铜品位具有显著的提升作用,但对铜回收率的降低也较明显。     

煤泥浮选工艺参数对浮选指标影响的试验研究

采用XFDⅣ型浮选机对汾西紫金矿选煤厂浮选入料进行浮选试验,研究了浮选机充气量、叶轮转速和药剂配比及用量对煤泥浮选指标的影响。试验结果表明:当浮选机充气量为150 L/h、转速为1 800 r/min,捕收剂和起泡剂配比为4∶1,捕收剂和起泡剂用量分别为1 200 g/t和300 g/t时,浮选效果最好。     

The hydrodynamics of an operating flash flotation cell

Key parameters for evaluating the hydrodynamic conditions within an operating flash flotation cell have been investigated. Profiles of the slurry at increasing depth within the cell have shown a strong trend of increasing slurry density (per cent solids) and coarseness (P₈₀), with a clear indication of segregation on the basis of particle specific gravity. Results of local gas dispersion measurements, taken with the Anglo-Platinum Bubble Sizer, show that bubble coalescence is occurring at shallower depths within the cell and there is a clear trend of decreasing gas velocity (J_g) with increasing depth at the axial location of measurement. Due to access restrictions gas dispersion measurements were taken close to the cell wall, but all data obtained falls well below the recommended minimum values for mechanically driven conventional flotation cells. However, the flash flotation environment is significantly different to a conventional cell, with higher per cent solids and a significantly coarser feed material, making this comparison qualitative (as unfortunately within the literature, there exists no other flash flotation data sets of this nature on which to base a comparison). The residence time distribution of solids indicates a significant amount of short-circuiting and/or internal recycle within the cell. Yet despite these findings, this cell contributes up to half of the pyrite recovery to the final concentrate at a very high grade.     

基于浮选柱的高灰煤泥浮选参数优化研究

阐述了高灰煤泥产生的原因及其浮选研究现状,介绍了旋流微泡浮选柱的特点及其对高灰煤泥浮选的适应性。利用实验室浮选柱试验系统,对邢台矿选煤厂高灰煤泥进行了浮选试验,并运用Design-Expert软件对试验结果进行了分析,得出最优浮选条件:捕收剂用量为2 400 g/t,入浮浓度为100 g/L,药比为8∶1,此时精煤产率为57.13%,精煤灰分为9.35%,尾煤灰分为48.63%,浮选完善指标为49.99%。     

Effects of hydrodynamic parameters on entrainment and flotation performance

The separation selectivity and efficiency of the flotation process depends not only on differences in the physico-chemical surface properties of various minerals within an ore, but also on the hydrodynamics of flotation. The hydrodynamics relate directly to many sub-processes of the flotation, such as suspension of particles in the pulp, dispersion of the air into bubbles and the probability of particle–bubble collision. Mechanical entrainment plays a major role in the quality of the flotation concentrate and the separation selectivity. Therefore, the effects of some important hydrodynamic parameters on both the entrainment and the flotation performance were investigated by means of a fractional factorial experimental design. Furthermore, many flotation tests were performed in order to generate sufficient data for use in empirical modelling and neural network based modelling, in light of the results of the experimental design. The adaptability and reliability of the models developed, depending on the treatment of available experimental data, have been studied comprehensively. Evaluation of the observed and predicted results demonstrated that the effect of some chemical and hydrodynamic parameters of the flotation process on both the metallurgical performance and entrainment in the training region, can successfully be predicted, with an error of less than 6%, by using the developed neural networks models without particular assumptions and additional experiments. In order to prove the validation of the empirical and neural networks models developed and to compare their performances, a few additional tests were conducted under predetermined flotation conditions. The results of these additional flotation tests indicated that the neural network models were consistently more accurate than the empirical models with a negligible error.     

半直接浮选工艺的研究与应用效果分析

为了解决原煤脱粉、块煤跳汰分选、煤泥浮选联合工艺中浮选入料浓度低的问题,在对直接浮选工艺与浓缩浮选工艺分析的基础上,提出煤泥水半直接浮选工艺,并探索跳汰浊水选煤的可行性和浮选入料的最佳入浮浓度。研究结果表明:煤泥半直接浮选工艺可以有效提高浮选入料浓度,并能够根据原煤中粉煤含量的变化在线调节浮选入料浓度;浮选系统、浓缩系统的煤泥仍为进入生产系统的全部煤泥,但由于浮选入料浓度升高,浮选系统、浓缩系统的入料量减小,所需设备的型号变小;东于选煤厂设计采用该浮选工艺,建设投资可降低10.80个百分点,生产加工成本可降低8.60个百分点。     

Effect of Jameson cell operating variables and design characteristics on quartz-dodecylamine flotation system

The Jameson cell is a relative newcomer to separation science and technology. Its mode of operation and mechanisms differ drastically from the other flotation machines. It has a number of unique parameters affecting flotation performance. An experimental investigation of Jameson cell operating variables and some design features was carried out within the quartz-dodecylamine flotation system. These parameters included jet length, bias, % solids, downcomer plunge length, and tank diameter studied for up to three different particle size groups (i.e., −250 + 106, −106 + 53 and −53 μm). The recovery of the medium and coarse size particles dropped by 10–15% as the free jet length increased, while that of fines was nearly independent of it. The bias factor negatively affected the recovery of all three size groups almost by same proportion. The effect of the downcomer plunging length on recovery was generally negative, but it was significant only for the coarsest size groups when the plunging length was beyond 50 cm. These negative effects on flotation recovery were mostly attributed to turbulence and its particle size dependent characteristics.     

Effects of operating parameters on the efficiency of dry stirred milling

Stirred media milling is an industrially accepted efficient grinding method for fine and coarse particles. The stirred mills can be operated both in vertical and horizontal configurations and the selection depending on the process variables. Successful operation of horizontal stirred milling (i.e. IsaMill) in wet applications encouraged the studies in dry applications. In this study, series of dry grinding tests were performed in a prototype horizontal stirred mill (42 L) to investigate the effects of operating parameters such as stirrer speed, feed rate, media filling and ball size on grinding considering the degree of size reduction and the energy consumption. The test results have shown that the stirrer speed, the media size and the media filling are directly proportional and the feed rate is inversely proportional with the specific energy consumption. Besides, energy savings up to 27% were achieved by adjusting the milling conditions properly (suitable media size) and the size reduction values (F₅₀/P₅₀) were between 1.05 and 2.42.     

基于Canny算子的浮选气泡形态特征参数提取

浮选过程中微观气泡的形态特征参数对浮选条件实验及机理研究具有重要意义,本文提出了一种基于气泡区域选取及Canny边缘检测的气泡形态特征提取的方法。首先,将拍摄到的浮选气泡图像进行预处理操作,阈值分割后的二值图像与原图像矩阵相乘得到气泡区域图像;然后利用Canny边缘检测提取气泡边缘坐标参数,基于此坐标信息计算出气泡面积、周长、圆心位置等参数,并实现向物理参数的转换。结果表明,此参数提取方法鲁棒性强、精度高,适用于光照不均和噪声干扰等复杂环境下气泡形态特征参数的提取。     

Evaluation of technological parameters for apatite extraction by surface miners

The article describes the research results on evaluation of rational technological parameters for open pit mining of Oshurkovo apatite deposit using Wirtgen Surface Miners. Basic relations between the surface miner capacity, ground conditions and technological factors are substantiated. The authors have constructed lag models and determined optimal design capacity of the open pit mine.     

马头洗选厂浮选操作方案的探索与实践

为解决马头洗选厂浮选系统入浮煤泥量大、浮选难度高的问题,通过改进浮选系统和完善浮选操作制度,探索出可行的浮选操作方案。生产实践表明:该操作方案为浮选系统的正常运行提供了有力保障,目前浮选系统生产效果良好,东西两系统的入浮煤泥矿浆量在1 700 m3/h左右,浮选精煤灰分在10.00%~11.00%之间,浮选尾煤灰分55.00%以上,每吨精煤的浮选药剂用量为0.38 kg,甚至下降至0.33 kg,由此带来的经济效益比较显著。     

Influence of the propagation of three phase contact line on flotation recovery

Froth flotation is considered the most effective process of beneficiating low grade ores and is widely used in the base metals industry. For effective flotation, the attachment of mineral particles to air bubbles is important and has been studied by many researchers by measuring quantities such as attachment time, film-thinning time and induction time. This paper identifies an important step in the bubble–particle attachment process, namely, the expansion mechanism of the three phase contact (TPC) line between liquid, solid and air. It has been shown that the TPC expansion time is determined by the drainage of the surrounding fluid. It is influenced by factors such as pulp chemistry surrounding the particle, variations in surface forces and pressure inside the bubble. It has been observed experimentally that the TPC expansion time bears square root relationship to attachment efficiency. In this work, it has been argued that the attachment efficiency is related to the TPC circle radius propagation.     

Study on the operating parameters of the 10 kW SOFC-CHP system with syngas

Solid oxide fuel cell combined with heat and power (SOFC-CHP) system is a distributed power generation system with low pollution and high efficiency.In this pap...