闭路磨磷矿石制浆的设计及应用

某磷肥项目磷酸装置的原料制备采用棒磨机十分级机＋球磨机的湿法闭路磨矿工艺。介绍了该工艺的原料粒度分布、工艺流程和系统控制；论述了棒磨机、斜窄流分级机等主要设备的工作原理和结构特征；通过磨矿系统产品分析数据，总结了湿法闭路磨矿工艺的应用效果和相关注意事项。     

离心式超细空气分级机研究——气流粉碎系统工艺参数优化

采用正交试验方法,研究与粉碎机组成系统的离心式超细空气分级机的工艺参数优化问题。在正交试验的基础上,得出最优工况条件。试验表明,分级机的转速、加料量、二次风量是影响分级机分级效率、分级粒径的主要因素。采用最小二乘法,对正交试验结果进行回归分析,得出可为控制分级粒径进而实现目标分级服务的经验公式。     

A comparison of the Bond method for sizing wet tumbling ball mills with a size—mass balance simulation model

A comparison is made of the results from a ball mill model simulation with those of the conventional Bond ball mill design method, for a material whose breakage characteristics and Work Index have been determined. In order to perform the simulation, ‘normal’ values were chosen for make-up feed size distribution, mill residence time distribution, ball mix, classifier behaviour, etc. At high flow rates through a mill (low reduction ratio), it is necessary to allow for the reduction in breakage rates caused by over-filling of the mill, using an empirical mass transfer relation: filling

. By suitable choice of the constant in this relation, it was found possible to duplicate the variation of mill capacity with feed size and product size (in wet closed-circuit grinding) predicted by the Bond method. The simulation model is then used to predict the variation of performance with design variables not included in the Bond method.     

A combined tracer and back-calculation method for determining particulate breakage functions in ball milling.: Part III. Simulation of an open-circuit continuous milling system

The combined tracer and backcalculation method for determining particulate breakage parameters described in Part I of this paper and applied to batch ball milling in Part II is extended here to the open-circuit continuous ball milling of martite iron ore. Breakage parameters are determined by this method in the continuous ball mill in the batch mode of operation. Residence time distributions are obtained in the continuous mode of operation with radioactive tracers. Segregated flow, models based on the dispersion model and the tanks-in-series model are given for use with the breakage parameter and residence time distribution data to predict product weight—size distributions. A particular model based on three perfectly mixed tanks in series is used to describe a mill with entrance and exit trunnions and is compared to both transient and steady-state experimental results. The comparison indicates that this method of simulation will be useful.     

基于智能控制系统的陶瓷球磨机神经网络控制方法的开发

介绍了球磨机负荷智能监控系统的整体结构设计。采用声发射波传感器提取信号，用分布式的微型控制器控制球磨机的运行状态，保证了球磨机的良好运行。同时，笔者基于神经网络的概念具体分析了智能控制系统的控制方法的开发步骤，引入神经网络对球磨机模型进行辨识，通过对物理特性跟踪实现对产量的控制，使其以最小方差保持在最佳值附近，以便实现高产、稳产。     

6R梯形磨在铝用炭素生产中的应用

针对国内外炭素行业早期磨粉用球磨机及后来又开发的风扫磨，即球磨机加风选系统在运行中存在燥声大，出粉率低，投资大等缺点，山东晨阳碳素股份有限公司经多方考察6R梯形磨，在炭素生产中采用了梯形磨粉系统。本文介绍了该系统组成及特点、运行效果，以期对炭素行业有借鉴作用。     

The back-calculation of specific rates of breakage from continuous mill data

Computer programs for back-calculation of specific rates of breakage S_i from continuous mill data, or batch grinding data, are described. A series of statistical tests to determine the statistically acceptable ranges of values are presented. The most reliable test uses independent estimates of error variance calculated from replicated data. It is shown that the interval-by-interval method of calculating S_i values is especially subject to errors in the top sizes. Back-calculation methods which use only the circuit product in the calculation give different ranges of statistically acceptable values than those which use all the size distributions round the circuit. The statistically acceptable ranges of values from using only the circuit product often do not include the values determined by direct laboratory investigation, and tend to be wider than the ranges given by using all the size distributions; thus, using only circuit product is a non-preferred method. The use of a fully-mixed residence time distribution (RTD) instead of a true RTD leads to radically incorrect values, which cannot be detected by statistical analysis except in the presence of unrealistically low experimental error. It must be realized that a set of breakage parameters which reproduce the data used in their back-calculation with good accuracy are not necessarily real, and statistical analysis is essential to define the statistically acceptable ranges of the parameters.     

中国超细粉碎和精细分级技术现状及发展

综述了中国超细粉碎与精细分级技术与设备的现状、近5年的进展 .20世纪90年代中期以来,中国超细粉碎和分级技术取得了显著进步,现已具备了研制和生产气流粉碎机、高速机械冲击式超细粉碎机、搅拌球磨机、振动球磨机、塔式搅拌磨、行星球磨机、高压射流磨、旋风自磨机等各类超细粉碎及涡轮式气流分级机和离心式水力分级机等设备的能力,并在流态化床式气流粉碎机、飓风自磨机、搅拌球磨机和砂磨机、行星球磨机、高压水射流磨机以及精细分级原理和分级设备等方面取得了一些进展,具有自主知识产权的新技术、新设备显著增多.指出中国目前在超细粉碎和精细分级领域仍然存在大型设备不足、工艺控制技术落后、磨耗和单位产品能耗偏高、特殊粒形超细粉体的生产工艺和设备落后等问题.最后对21世纪初中国超细粉碎和分级技术的主要发展趋势进行了展望.     

A generalized transfer parameter treatment of crushing and grinding circuit simulation

A generalized transfer parameter treatment for simulation models of crushing and grinding devices is presented. The treatment is illustrated for existing models of batch and continuous ball mills, air-swept ball mills, vertical (ball-and-race) mills, and double-roll crushers. An extension of the treatment to size reduction devices in closed circuit is given and a single algorithm for simulating open and three common closed circuit configurations is described.     

几种典型水泥粉磨系统的比较

水泥粉磨系统已由早先的球磨机系统逐步发展到现在的球磨机+辊压机系统和立磨系统。通过分析流程和主要配置及运行参数,归类出比较典型的七种水泥粉磨系统的技术性能持点。其中,立磨终粉磨系统流程最简单,能耗最低,是水泥粉磨方案的首选;辊压机+球磨(带涡流选粉机)组成的联合粉磨系统及立磨和球磨组成的联合粉磨系统流程相近,能耗相近,可作为水泥粉磨系统的优选方案;辊压机和球磨机组成的开流及半开流系统缺点最多,应尽量避免选用。     

改造电气控制系统提高球磨机工作效率

在球磨机励磁柜中，利用集成电路晶闸管控制单元取代原有励磁系统，解决了由于球磨机电气控制系统存在缺陷而引起生产不正常问题。能使球磨机生产过程中，故障率降低、运行稳定，降低生产成本，保证了企业连续、稳定的生产磷矿粉。     

Determination of ball mill residence time distributions form tracer data taken in closed-circuit operation

Based on a method which searches on the parameter values for models, the possible one- and two-detection system tracer methods for the determination of ball mill residence time distributions from data taken on closed-circuit recycle systems are treated. Mathematical relationships for the most promising approaches are developed for both methods. This includes deriving, demonstrating, and verifying (with existing simple analytical models of closed-circuit mills) analytical models of tracer input and output based on the use of tanks-in-series and finite stage models with the convolution integral principle. Simulated results for typical processes are given and non-linear search methods are described and demonstrated for determining mill residence time distribution model parameters.     

Optimization of variables in grinding brass particles for paint and pigment industry

Flaky metal powders commonly used as paint and pigments, are generally produced by grinding in ball mills or vibration mills. The key to good quality powder production is to optimize the processing parameters. In the present work grinding of brass particles is studied in detail in a laboratory size ball mill to determine the optimal levels of the ball to material ratio, type and amount of additives, mill speed, ball load, etc. The quality of the powder is assessed on the basis of water coverage, degree of flattening and luster by visual inspection. Preliminary results in a 35 cm diameter ball mill with 30% ball load show that a material to ball ratio of 0.067 with a 0.1% dosage of stearic acid is required for good quality powder. For determining optimal mill speed and ball size a 2² factorial design of experiment has been followed. It has been determined that to achieve best powder quality the mill must run at 70% critical speed and the ball size must not exceed 20 mm. The quality of the powder assessed through SEM study for surface morphology and particle size analysis compares very well with the industrial samples.     

Radial mixing of particles in a dry batch ball mill

Poor mixing in dry ball mills can lead to insufficient presentation of fine particles to the classifying air, overgrinding of particles and wastage of energy in a ball mill. A video capture method has been used to study radial mixing kinetics in a dry batch ball mill. Experiments were conducted in a ball mill with PVC plastic powders being used as particles so that the effect of size reduction could be neglected. Radial mixing in ball mills was studied at typical industrial speeds of 75%, 80% and 90% of critical. The rate of particle mixing was observed to increase with increasing mill speed. A simplified mathematical model is presented that can be used to predict the radial mixing of particles in a ball mill. A parameter, k, was used to quantify the kinetics of mixing as affected by the mill's speed.     

RESIDENCE TIME DISTRIBUTION IN AN OPEN REACTOR:EFFECT OF BACKGROUND REACTANT ON TRACER DISPERSION

A new approach is presented for deriving the residence time distribution(RTD)in open-type reactors with exclusion of residence in the fore section.Inasmuch as failure to predict the con-version of chemical reactions has been evidenced in many occasions,numerical solution of tracerdispersion in the presence of background concentration gradient of reactant is given to demonstratethe strong effect of background reactant on the true RTD a reactant molecule experiences.Withinthe error of computation,the conversion of a first-order chemical reaction under steady state is shownto be equal in both closed and open reactors,despite difference in relevant RTDs     

大规格球磨机球磨釉料的探讨

8吨球磨机应用氧化铝刚玉质异形砖与普通瓷质砖砌筑成具有过渡圆角及不连续螺旋的新结构内衬（以下简称为新内衬），在广东某大型企业的生产线上球磨陶瓷耐磨地砖釉料，并就釉料颗粒大小及粒度分布、电耗、介质磨耗等与1．5吨球磨机进行对比，进行了实验研究。结果表明：配有新内衬的8吨球磨机可磨出颗粒较小、粒度分布较窄的质量好的釉料，且具有好的经济效益；在墙地砖大批量生产的条件下，采用新内衬的8吨等大规格球磨机替代1．5吨球磨机球磨普通釉料切实可行。     

Empirical and scale-up modeling in stirred ball mills

Stirred ball mills are frequently used for ultrafine- and nanogrinding in food, pharmaceutical and chemical industry, but only few investigations have been published on empirical or scale-up modeling of stirred ball mills. Experiments have been carried out with a laboratory scale stirred ball mill. During the experiments the main technical parameters such as stirrer speed, grinding media, filling ratio, grinding time and the solid mass concentration have been systematically adjusted. The particle size distribution of mill products can be well estimated by empirical functions, so an empirical model has been prepared for the laboratory mill. The relation between the grinding fineness, grinding time and specific grinding work was represented for several materials such as pumice, andesite, limestone and tailings of ore mining industry. The power consumption of the stirred ball mill for scale-up was determined by a method based on the dimensional analysis. A new scale-up model has been presented as well by with industrial size stirred ball mills can be designed on the basis of the laboratory measurements.     

立磨选粉机叶片结构对分级区速度场影响分析

立磨选粉机分级区速度场是影响其分级性能的主要因素之一,其机内气固两相流为非理想流体。本文应用流体力学流体黏滞性与速度梯度原理,分析了速度梯度过大造成选粉机选粉精度和选粉效率下降的机理。通过构建不同叶片结构转笼的立磨选粉机模型,采用Fluent软件模拟分析了立磨选粉机不同叶片结构转笼的分级区速度场中速度流向、速度大小与速度梯度的变化规律。进行了立磨选粉机转笼叶片结构改造试验,试验表明：改造后的Z形叶片结构转笼的立磨选粉机产量在直叶片转笼结构的基础上提高了15 t/h,且0.08 mm颗粒的筛余降低了10%。     

球磨和立磨矿渣粉对矿渣水泥性能的影响研究

通过激光粒度分析仪(LPS)分析球磨和立磨粉磨的矿渣粉粒度,并用旋转黏度计测定矿渣水泥流变性能及胶砂强度。结果表明:球磨机加工的矿渣粉比立磨加工的矿渣粉颗粒粒度分布宽、细颗粒含量高;矿渣粉比表面积相近时,2种矿渣水泥的流变性能相差不大,球磨矿渣水泥的强度比立磨的稍好。     

立磨选粉机分级环间距对分级性能的影响

分级环间距大小是影响选粉机分级性能指标的重要因素之一。通过构建不同分级环间距的立磨选粉机模型,采用Fluent软件对SMG5500型立磨选粉机不同分级环间距下的流场特性进行研究,对比分析间距大小对速度场、压力场和分级效率的影响规律,得出最优的分级环间距,并对整机进行实验验证。数值模拟结果表明:当分级环间距过小时,大部分大于80 μm的粗颗粒都能进入转笼,使产品极易出现跑粗现象;当分级环间距过大时,大部分小于80 μm的颗粒不能进入转笼,这使得选粉机的循环负荷加大,选粉效率受到了极大的限制;当分级环间距为110 mm左右时,SMG5500型立磨选粉机的分级性能最优。