浮选机尾液控排闸的问题及改进

在“浮选生产中，浮选机容槽中矿浆的液面高度与浮选产品的回收率以及品位有着重要关系。矿浆液面高度则主要取决于设置在浮选机组末槽尾壁板上部的大控排闸和下部的小控排闸对废尾液外排的开度。因此，浮选机尾液控排问应该具备高可靠性，所以，浮选机有的尾液控排闸有必要加以改进。 １大控排闸 大控排闸是主要控排问，浮选机组容槽的液面高度，几乎完全依靠该闸来调控。 １．１存在的问题 现有的控排问（如图１）性能不佳，其主要原因为： （１）闸板密封性差。闸板２与升降杆１呈刚性连接，这种结构要求闸板２的平面平行于闸板的升降轨…     

矿物浮选动力学模型及影响因素研究进展

浮选动力学可对浮选过程进行量化描述,有助于提升选矿自动化水平,近年来受到了越来越多重视。基于浮选动力学模型的发展历程,综述了矿物晶体结构、矿物颗粒大小、矿物颗粒形状、药剂作用及浮 选设备影响等因素对矿物浮选动力学的影响。此外,还展望了浮选动力学发展,指出运用理论计算分析并结合矿物工艺学及矿浆流体运动规律可进一步加强浮选动力学模型对实际浮选过程的指导意义。     

浮选动力学研究进展

介绍了浮选动力学研究的发展历程,从浮选动力学实用性模型、应用浮选动力学解释浮选行为及浮选流程的合理性、浮选设备的浮选动力学研究3个方面论述了浮选动力学的研究进展,展望了浮选动力学研究今后的发展方向。     

排液采气技术在中原油田的应用

稳产和提高采收率,这是气田开发工作者不断追求的目标,除了对气藏工程、气井及气藏动态的深入研究分析和正确认识外,采气工艺技术是一项必不可少的手段.中原油田由于气藏类型多,气井存在的问题也复杂,这就对采气工艺的适应性提出了更高的要求.通过对中原油田气田开发动态特征及气井存在的主要问题的分析,论述了排液采气技术在中原油田的具体应用情况,并提出了一些建议.     

选矿厂过滤系统自动排液装置的改进

介绍永平铜矿选矿厂精矿过滤系统原自动排液装置的使用情况、存在问题及改进经验。     

陶瓷过滤机排液系统改进

雅矿公司选矿厂原有排液系统因真空泵、滤液泵故障率高造成陶瓷过滤机运行不平稳、故障率高而无法满足生产需要。经对排液系统原理的分析研究,最终通过技术改造实现了真空泵可靠运行及滤液罐自动排液,保证了陶瓷过滤机的正常运行,产生了很好的经济效益。     

大型真空过滤机的新型自动排液装置的开发与应用

开发了一种适用于大型真空过滤机气水分离要求的新型自动排液装置,通过理论计算,该新型装置满足了单机过滤面积200 m2的大型真空过滤机排液量的工艺要求。该装置已应用于俄罗斯斯科沃罗季诺区某金矿选矿厂的尾矿过滤作业。生产实践表明,该新型装置具有排液量大、运行稳定等特点,有良好的推广应用前景。     

陶瓷过滤机三种排液装置的比较分析

论述陶瓷过滤机脱水系统采取的三种排液装置,即滤泵排液装置、高差排液装置、自动排液装置。通过三种排液装置的对比分析,采用自动排液装置的脱水系统运行稳定,故障率较低,值得全面推广使用。     

压裂返排液水质在线检测控制技术研究及应用

对压裂返排液在线水质检测方法进行了分析。同时,详细讲述了压裂返排液在线离子检测的难点、检测工艺、控制算法及压裂返排液在线检测控制系统应用情况。压裂返排液在线检测控制系统具有运行稳定、节省药剂、可靠性高等优点,保证了压裂返排液处理后出水的稳定性。     

颗粒气泡黏附科学:基于AFM和DWFA的颗粒气泡间疏水作用力研究

为探索颗粒气泡体系疏水力的长程及短程来源机制,分别采用原子力显微镜(AFM)和浮选动态润湿膜分析仪(DWFA)对气泡与同一疏水玻璃基板间的疏水力进行测试。AFM发现气泡与亲水性玻璃基板间的相互作用力为单调斥力作用,体系不存在诱发液膜失稳的引力作用项。疏水性颗粒气泡间的液膜是不稳定的,当AFM负载力到达19. 3 nN时,力曲线中观察到了明显的跳入黏附现象。疏水玻璃与气泡间的疏水力以3. 50 nm的衰减长度按单指数模型衰减,液膜在32. 96 nm临界破裂厚度处破裂。该疏水力倾向于一种短程力(50 nm),其源自界面的水分子重排熵效应。DWFA法同样发现亲水性玻璃基板与气泡间的液膜是稳定的,当总分离压力与气泡内部拉普拉斯压力相等时,液膜到达133 nm的平衡膜厚度。疏水性玻璃基板与气泡间的液膜是不稳定的,液膜发生快速薄化并分别在185 nm临界膜厚处破裂。对疏水力进行定量求解发现该力以47. 30 nm的衰减长度衰减,所获得的疏水力为一种长程作用力,该力源于固液界面纳米气泡空化效应。AFM和DWFA排液试验中所用的气泡尺寸分别为微米级及毫米级,疏水力受气泡本身的尺寸影响,与气泡表面的毛细波传播有关,在吸引力作用下大气泡表面会形成更强烈的毛细波震荡。由于疏水界面水分子的热力学不稳定性,这种界面波动会诱发疏水固液界面空化气泡的析出,增加了引力作用程。     

颗粒气泡黏附科学——宏观尺度下颗粒气泡黏附研究进展及困境

颗粒气泡黏附指从颗粒与气泡相遇开始到液膜发生薄化破裂最后至三相润湿周边铺展形成稳定矿化气絮体的过程,是浮选中的核心作用单元。然而浮选颗粒气泡黏附机理至今仍不明确。黏附过程主要受颗粒气泡的表面物理化学性质及溶液化学条件影响,表面力及流体作用力协同支配微纳尺度下颗粒气泡间液膜薄化破裂行为。排液过程中气液界面的变形效应进一步增加了系统复杂性,上述因素使得颗粒气泡黏附的理论研究及试验探索步履维艰。早期关于颗粒气泡黏附的研究主要聚焦于黏附概率,其中宏观尺度下的诱导时间测试占据主导地位,通过诱导时间结果计算黏附概率。对国内外宏观尺度下颗粒气泡黏附概率模型及研究技术手段进展展开全面综述,并对现有技术瓶颈及局限进行分析。诱导时间测量仪及高速动态摄影技术大大促进了浮选工作者对颗粒气泡黏附的理解,“诱导时间与实际浮选回收率具有着良好的相关关系”也已经被广泛证明。然而因微纳尺度下的表面力及液膜薄化动力学信息的缺失导致宏观诱导时间并不能从基础层面揭示颗粒气泡的黏附机理,微纳尺度下颗粒气泡间相互作用力及液膜薄化动力学的定量测试表征是技术发展的必然趋势,其可为浮选微观矿化反应过程提供新的理论视角,同时也为难浮煤及难选矿浮选过程强化提供理论支撑。     

Quantifying particle pick up at a pendant bubble: A study of non-hydrophobic particle–bubble interaction

To study bubble interaction with non-hydrophobic particles an imaging technique has been developed to quantify particle pick up at a pendant bubble by measuring the bubble–particle attachment angle (BPA) made by the particle bed on the bubble. The technique was verified by correlating pick up mass against BPA. Pick up of alumina was shown to correlate with difference in alumina and bubble zeta potential supporting an electrostatic model of interaction with non-hydrophobic particles. Pick up also correlated with contact angle (Washburn method) indicating the electrostatic force is sufficient to establish a solid–air interface.     

红柱石与石英之间浮选交互影响研究

红柱石与石英之间浮选交互影响研究发现：在pH值为8、FeCl3?6H2O用量20 mg/L、油酸钠用量150 mg/L时,红柱石与石英颗粒间界面力的相互作用距离越小,总E-DLVO势能的负值越大,说明各粒级石英与不同粒级红柱石的作用力为吸引力,相互之间存在粘附罩盖。通过显微镜观察进一步验证了红柱石与石英之间确实发生了粘附现象。红柱石与石英浮选交互影响的主要作用形式为矿物间的相互粘附罩盖,包括细粒级石英可以向粗粒级红柱石粘附,表现为矿泥罩盖;细粒级红柱石可以向粗粒级石英粘附;细粒级红柱石可以与细粒级石英粘附聚集。在油酸钠体系中,可以利用柠檬酸来有效削弱石英与红柱石之间的粘附罩盖作用,柠檬酸对红柱石与石英的分离效果比较好的作用集中在-106+45 μm和-45+18 μm粒级。     

Influence of galvanic interaction between chalcopyrite and some metallic materials on flotation

Galvanic interactions between the grinding media and the ground mineral inside a ball mill could not only accelerate the media wear but also adversely affect the flotation response of the ground mineral. Rest potential, combination potential and galvanic current measurements were carried out to understand the probable electrochemical interactions between chalcopyrite and several metallic electrodes such as platinum, stainless steel, hyper steel, mild steel and cast iron. Flotation recovery of chalcopyrite was found to be significantly lowered when contacted with hyper steel, mild steel or cast iron prior to flotation unlike with platinum or stainless steel. The influence of the presence of collector during galvanic interaction as well as the effect of relaxation for fresh and galvanically interacted chalcopyrite samples were also studied with respect to its floatability. AES and ESCA analyses indicated that galvanic coupling of chalcopyrite with a hyper steel grinding medium resulted in the formation of hydroxide or oxide species of iron on the mineral surface. An electrochemical mechanism is proposed to explain the mineral-grinding media interaction and its effect on flotation.     

Influence of liberation on bubble–particle attachment time in flotation

Flotation is controlled by the bubble–particle attachment mechanism which depends on the particle surface properties i.e., the particle composition, the surface liberation of valuable minerals and collector adsorption. This paper focuses on using the bubble–particle attachment method to understand the factors affecting attachment time. The attachment time measurements were performed with sized concentrates obtained by flotation of a copper sulphide ore (Northparkes Mine, Australia) in a mechanically agitated batch flotation cell. Quantitative mineral liberation analysis was used to determine the mineralogy of flotation concentrates. The results showed that the higher the amount of highly and moderately liberated copper minerals in flotation concentrates, the lower the attachment time. By using attachment time and collector dosage, we defined a non-linear empirical correlation to estimate Cu grade. The proposed empirical correlation has shown a satisfactory agreement between the calculated and the experimental Cu grade. These results showed that attachment time measurements are related to the Cu grade. This relationship may be used in the future to develop a practical method (without assays) to monitor changing grade for a specified system (flotation plant). It also may be possible to infer potential grade if mineralogy samples are available, but not enough samples are available for conventional flotation tests. However this requires a significant amount of further work.     

A comparison of methods for measuring the induction time for bubble–particle attachment

Froth flotation is an exceedingly complex physicochemical process. The convenience of distilling much of the complexity of the particle–bubble interactions into a single parameter has led to the continuing popularity of the classical ‘induction time’ to quantify the threshold for particle–bubble attachment to occur. Despite this popularity and the simplicity of the concept, there is no single universal method of evaluating the induction period.In this paper, we begin with a critical review of the available techniques for estimating the induction period. These are: back-calculation from experimental (micro)flotation tests; pushing a particle toward a stationary bubble (or vice versa) using an atomic force microscope (AFM); pushing a bubble toward a stationary bed of particles in the ‘Induction Timer’; pushing a bubble toward a stationary solid surface using the ‘integrated thin film drainage apparatus’ (ITFDA); and dropping particles onto a submerged stationary bubble using the ‘Milli-Timer’ device. Each one of these methods has advantages and disadvantages, and the best choice depends on the application.In the experimental section, we present quantitative comparison of the induction periods estimated using two different techniques, namely the Induction Timer and the Milli-Timer. The same particles were tested in each device, under the same conditions. It was found that by tuning the operation of the particle pick-up device, similar estimates of induction period could be obtained to the estimates made by direct observation with the Milli-Timer. In the former device a bubble is driven toward a particle bed at a controlled rate, whereas in the latter a particle’s motion is governed by the hydrodynamics. The potential to match these presents an intriguing prospect for better understanding the bubble–particle interaction, and the possibility to ‘calibrate’ the simpler Induction Timer against direct observations.     

Estimate of the long-range interactions between hydrophobic surfaces as applied to flotation of sulphide minerals

Using pyrite, chalcopyrite and sphalerite for exemplification, the forces of electrostatic repulsion and hydrophobic attraction between particles are estimated. Based on the experimentally obtained values of the induction time, the limit thickness of a wetting film is calculated to demonstrate the long-range behavior of the attraction forces between sulphides and an air bubble. It is established that the surface hydrophobicity of the tested sulphides increases under the action of a hydrophobic polymer and compounded collecting agents (isopropyl ethyl thiocarbamate and butyl xanthate). This fact enables enhancing the extraction of zinc and sulphide products from tailings of copper-zinc ore concentration. __________ Translated from Fiziko-Tekhnicheskie Problemy Razrabotki Poleznykh Iskopaemykh, No. 5, pp. 107–114, September–October, 2006.     

A relationship between the bubble-particle attachment time and the mineralogy of a copper-sulphide ore

Flotation performance depends on bubble-particle attachment which is controlled by the particle surface properties which include the particle composition and the surface liberation of valuable minerals. This paper discusses the contribution of liberation of valuable minerals to bubble-particle attachment time measurements, under constant chemical conditions. The bubble-particle attachment time measurements were performed using a sized fraction from concentrates obtained at different times and tails by flotation of a copper-gold sulphide ore (Northparkes Mine, Australia) in a mechanically agitated batch flotation cell. All products and tails were analyzed using quantitative mineral liberation analysis. The results showed that there was a relationship between the time of the concentrate collected, the Cu grade of the sample and the bubble-particle attachment time, and that the measurements were most sensitive to the amount of unliberated material. The fast floating material was higher grade, with a lower attachment time indicating that the measured bubble-particle attachment time could be used to characterize flotation performance of an ore.     

基于耦合动力学模型的围岩-支架相互作用分析

液压支架处于与围岩相互作用的工作环境中,因此掌握其耦合作用规律,对于液压支架的抗冲击、自调适设计具有十分重要的意义。以ZY12000/28/64支顶掩护式液压支架为研究对象,运用拉格朗日第二类动力学理论建立6自由度围岩-支架耦合动力学方程。应用该动力学方程,分析了基本顶质量、基本顶初始高度及断裂点位置对液压支架动力学响应的影响。结果表明,立柱千斤顶、平衡千斤顶的受力随着基本顶质量和基本顶初始高度的增加呈线性增大;随着断裂点位置的前移,立柱千斤顶受力增大、平衡千斤顶受力减小。