磨机中磨矿介质的运动规律

磨机工作时主要依靠筒体旋转时充填介质的冲击和研磨作用来粉碎物料。而对物料施加冲击和研磨力的大小与充填介质所处的运动状态有关,其中磨机转速和介质充填率影响磨矿介质的运动状态。一般来说大体存在泻落、抛落及泻落和抛落的混合三种运动状态。因此充填介质的运动状态是取得好的磨矿效果的关键所在。在运动过程中,由于介质与介质之间以及介质与磨机筒壁之间存在着摩擦力,使得充填介质在随筒体旋转做公转的同时,又绕其自身轴线做自转运动。本文主要通过无物料钢棒实验,分析研究了转速为56.3r/min、106.9r/min,磨矿介质充填率为40%、50%、55%条件下充填介质的运动状态及磨矿介质的公转和自转运动规律。最后分析导致充填介质的实际冲击速度值(通过实验所得)与理论冲击速度值(通过计算得到)产生差异的原因。     

行星球磨机磨球运动规律的研究

行星球磨机中磨球的运动规律主要由离心力决定。通过绘制磨球在球磨罐内不同位置所受离心力的分布情况，分析了磨球相对于球磨罐的运动轨迹，研究了球磨罐公转速度、自转速度、半径及磨球大小对磨球运动的影响，得出同时提高球磨罐的公转速度和自转速度或采用大直径的磨球可显著增强粉磨效果的结论，为行星磨操作参数的选择提供了理论依据。     

转筒式磨机内物料分布的参数分析

在参照物料动态平衡模型「１」的基础上，通过力学分析，获得磨筒内物料提升段与滑移段的分界面形状参数，并进一步分析了这些参数与磨机的转速、自转与公转的传动比、粉体摩擦系数、填充率、公转半径和筒体内径之间的关系。     

铁矿石细磨动力学和圆筒型磨矿机参数的选择

矿石在圆筒型磨矿机中的磨矿是矿石准备的主要工艺作业。影响磨矿机工作效率的诸因素是众所周知的。这就是圆筒的几何参数,磨矿介质的形状、尺寸和强度,磨矿负荷充填率,矿石的物理力学性质,磨矿机的转速等。但是,至今尚不能把粒度范围宽的待磨物料的磨矿效率评价准则,以及按实验室试验结果和数学预测数据选择最佳参数的方法奉为典范。磨矿动力学,即产品磨细度与磨     

离心磨矿机有用功率的试验研究

通过对离心磨矿机滚筒内介质运动和介质分布区域的分析 ,从理论上探讨了离心磨矿机有用功率计算表达式。通过试验比较 ,离心磨矿机具有较高的碎矿效率。计算表达式基本反映了离心磨矿机有用功率的总体情况 ,说明其表达式合理可行。试验还得知 ,离心磨矿机的有用功率为输入功率的 4 0 %左右 ,高于普通球磨机 (30 % )。其有用功率计算值与实测值基本相符     

利用过负荷指示器控制格子型球磨机的充填率

从1981年起,米哈伊洛夫采选公司成功地应用了21型放射性同位素探测仪进行4500×6000型球磨机充填率的自动控制。探测仪的工作原理基于γ-射线束经过排矿口照射磨矿机内部装料和记录散射回来的强度。型球磨机排矿部件经过改造之后,可以使γ-射线通入并作用于磨矿机内部装料,从而能够进行这些磨矿机充填率的放射性同位素控制(发明证书号:997803)。新克拉马托尔斯克机器制造生产联合公司从1988年开始向米哈伊洛夫和新克里沃罗格采选公司以及“磷灰石”生产联合公司提供其结构可以利     

锡石多金属硫化矿磨矿优化试验研究

为了缓解锡石多金属硫化矿在磨矿实践中存在锡石过磨与硫化矿欠磨的矛盾,优化其磨矿过程。本文采用单因素试验方法,研究操作因素如磨矿时间、磨矿浓度及磨机充填率对磨矿技术效率、矿石欠磨与过磨以及磨矿合格粒级产出影响规律。结果表明,在磨矿时间8min、磨矿浓度70%、充填率30%时,获得的磨矿技术效率最优。磨矿时间和充填率对锡石多金属硫化矿矿石欠磨与过磨及磨矿合格粒级产出影响较大,而磨矿浓度对其影响相对较小。研究结果可为后续的工业磨矿过程的优化提供试验数据。     

GN8型搅拌磨机产品粒度分布宽度的影响因素研究

为了研究GN8型搅拌磨机的磨矿效果,运用Rosin-Rammler分布函数分析了搅拌器转速、矿浆浓度和介质充填率对磨矿产品粒度分布宽度的影响规律。研究结果表明,增加搅拌器转速或介质充填率,有利于降低磨矿产品的粒度分布宽度;矿浆浓度在45%~60%范围内,其对磨矿产品的粒度分布宽度无影响。     

棒销式搅拌磨机流场的数值模拟分析

采用FLUENT对棒销式搅拌磨机磨腔内的流场进行数值模拟,通过分析流场速度、湍流强度和剪切率参数,研究了磨腔内流场的运动规律。结果表明,随着搅拌器转速的增加,流场内的能量传递充分性降低,能量利用下降。通过对其数值模拟的研究,更加直观的了解搅拌磨矿机磨矿作业的工作原理,为机械参数的优化设计提供了理论依据。     

磨矿机效率的提高

考虑以增加球磨机的矿石和球介质的方法,提高球磨机工作效率的可能性。球磨机的充填率增加0.4-0.5的,最重要的是磨矿机的生产能力提高了,电耗约降低20-23％。     

基于离散单元法的球磨机净驱动功率预测

球磨机筒体内装料（物料和研磨介质）的运动状况很复杂，过去在球磨机的设计中多采用类比法和经验公式来确定其驱动功率，存在一定的局限性。通过记录某水泥厂一台球磨机的运行数据，计算得到了它的净驱动功率值（仅使装料运动的功率）。随后运用PFC3D离散元软件在相同条件下对筒体内装料的运动进行了数值模拟得到了净驱动功率值，发现实际运行值与模拟值之间仅存在7．7％的相对误差。最后还对不同格条高度、旋转速度和装料填充率下的球磨机分别进行了数值模拟并得到了净驱动功率值的变化规律，所得结果与实际运行状况和理论分析基本吻合。     

基于EDEM球磨机颗粒的分布与接触特性分析

球磨机是矿山机械中对物料进行粉碎与研磨的主要设备之一。根据球磨机的尺寸与物料的接触参数,采用EDEM软件建立了球磨机离散元计算模型,研究了在不同的物料填充率、转速率以及衬板数量时球磨机内部颗粒接触数占比、颗粒分布情况的变化规律,结果表明：随着填充率、转速率以及衬板数量的增加,球磨机的研磨效率均出现了先增大后减小的趋势。在转速率为75%~85%,填充率为15%~25%,衬板数量在12~16时,球磨机的研磨效率最佳,且改变衬板数量对球磨机内部颗粒的运动特性的影响较小。     

Comparison of open and closed circuit HPGR application on dry grinding circuit performance

A conventional cement grinding circuit is composed of a two compartment tube mill, a mill filter which collects the fine material inside the mill and a dynamic air separator where final product with required fineness is collected. In general the material fed to the circuit has a top size of 50 mm which is very coarse for the ball mill. For this purpose, later in 1980s, high pressure grinding rolls (HPGR) has found applications as a pregrinder which increased throughput of the grinding circuit at the same fineness.In early applications, HPGR was operated in open circuit. But later as the operating principle of the equipment based on the compression, some portion of the HPGR discharge recycled back to improve efficiency of the mill or operated closed circuit with classifiers. Within this study effect of open and closed circuit HPGR applications on dry grinding circuit performance was examined. For this purpose sampling studies around three different cement grinding circuit were completed. In the first study, a circuit including open circuit HPGR, ball mill and air separator was sampled and chosen as the basic condition. As the final product size distribution is important for grinding circuit, model structure of each equipment was developed. The second and third surveys were carried out around closed circuit HPGR operation with V and VSK separator to develop models for the separators. Finally the separator models were used in basic condition to simulate closed circuit HPGR application.It was understood from the studies that closed circuit HPGR operation improved the overall circuit efficiency at the same final product fineness by reducing the specific energy consumption.     

Effect of High Pressure Grinding Rolls (HPGR) pre-grinding and ball mill intermediate diaphragm grate design on grinding capacity of an industrial scale two-compartment cement ball mill classification circuit

Effect of High Pressure Grinding Rolls (HPGR) pre-grinding and two-compartment ball mill intermediate diaphragm grate design on grinding capacity of an industrial scale conventional two-compartment ball mill cement grinding and classification circuit was investigated. For this purpose, cement clinker was crushed in an industrial scale HPGR in open circuit and fed to a Polysius® two-compartment ball mill and air classifier closed circuit. Two-compartment ball mill intermediate diaphragm middle grate design was changed when HPGR crushed clinker was fed to the circuit to obtain optimum flow of material from the first compartment into the second compartment. Modifications on the diaphragm design were required due to the increased throughput when processing HPGR product. Two sampling campaigns were performed at the steady state conditions of the circuit. Raw clinker (uncrushed clinker) was fed to the conventional two-compartment ball mill air classifier circuit in sampling campaign-1 whereas HPGR crushed clinker was fed to the same circuit with modifications on the intermediate diaphragm middle grate design in sampling campaign-2. Mass balanced tonnage and particle size distributions were estimated by using JKSimMet Steady State Mineral Processing Simulator in both sampling campaigns. Polysius® two-compartment ball mill was modeled by using perfect mixing modeling approach (Whiten, 1974). Specific discharge and breakage rates in the grinding compartments were estimated by using the two-compartment ball mill model structure proposed by Genç and Benzer (2015). Specific discharge rates were found to increase at coarse size ranges when raw clinker was fed to the circuit in compartment-1. However, specific discharge rates of particles were increased slightly at coarse size ranges in the second compartment at higher mill capacity condition. Specific breakage rates were increased when the circuit was fed with HPGR crushed clinker. Modifications in the circuit and the ball mill intermediate diaphragm grate design enabled the optimization of the grinding capacity of the conventional two-compartment ball mill cement grinding and classification circuit. Ball mill grinding and classification circuit capacity was increased by 10% and specific energy consumption of the ball mill was decreased by 9.1%.     

基于总体平衡模型的半自磨机在线自诊断工具开发

工业云服务是工业互联网智能化升级,实现数字矿山建设的重要手段。介绍了针对矿物加工磨矿流程中重要的大型磨矿设备开发数字化模拟模型,并利用工业云服务模式进行半自磨机在线自诊断功能实现的具体研究过程。结果表明,利用基于机理模型开发的半自磨机在线自诊断工具可以在不同选矿生产时段对半自磨机内部物料运动情况、磨矿产品粒度分布等重要信息进行量化计算,并可通过云服务的模式对结果进行快速的可视化展示。该在线自诊断工具不但可以为半自磨机运行状态分析提供直观的判断方法,还可对半自磨操作和流程优化提供建议。     

基于T-S模糊模型的棒磨机给料优化决策

针对磨矿过程中棒磨机时常出现不饱或胀肚,从而影响生产效率这一问题,提出了一种基于T-S模糊模型的棒磨机给料优化决策方法。根据棒磨工艺流程和操作经验,以棒磨机实际给料量及其与棒磨后的筛下给矿料的比较值作为前件,建立了一个棒磨机给料的非齐次T-S优化决策模糊模型。仿真结果表明,应用这一方法可使棒磨机给料量达到最优值。     

应用专家PID实现某矿山半自磨机的控制

为了解决国内某矿山[?]8.8 m×4.8 m型半自磨机的自动控制问题，采用专家PID控制系统进行了系统控制设计研究。结果表明：①影响半自磨机工作状况的因素较多，主要包括矿石性质、磨矿介质、给矿速率、磨矿浓度、衬板和格子板的状态等；物料充填状态可通过半自磨机的功率、轴压和磨音来判断，而料位状态控制可通过调节给矿量、给水量、加球量实现。②专家PID算法与传统PID的算法有明显的优势，其本质上是采用非线性设计手段，将专家经验引入控制策略的制定中，更适合复杂对象控制策略的实施，较好地克服常规PID对非线性系统适应性差、难以克服异常扰动以及对滞后时间常数难以确定等缺点。③在充分考虑了半自磨机工作特点的基础上，设计的专家PID控制系统可将半自磨机的轴压、功率稳定在设定值范围内，同时能根据半自磨机给矿量、给水量、顽石量、磨音等参数的综合分析，判断出半自磨机处于较为稳定的工作状态。     

立式行星磨启动时间的确定与动态仿真

分析了立式行星磨的结构特性,利用牛顿定理建立了系统的动力学方程.采用线性关系表示异步电动机启动阶段转速与时间的关系,计算出立式行星磨的启动时间范围为7.94～10.32 s.采用多体动力学软件ADAMs模拟了立式行星磨启动阶段的动态行为,建议实际操作时以适当的软启动方式启动,开车10 s后加入物料并使加料均匀.