球磨机钢球磨损量的检测与计算

球磨机钢球级配的选取和保持合理级配稳定不变,对球磨机产质量都是至关重要的影响因素。合适的级配确定后要想在长期生产中保持此级配基本不变,最主要的是要确切知道钢球的磨损速度,掌握恰当的补球数量和种类,尤其高耐磨的合金钢球,如铬钼合金钢球在使用中钢球特性和磨损情况有     

Energy efficiency of cement finish grinding in a dry batch ball mill

Dry grinding experiments on cement clinker were carried out using a laboratory batch ball mill equipped with torque measurement. The specific energy was found to be dependent on operating parameters and clinker environment. Additional compounds such as gypsum and pozzolanic tuff improve energy efficiency. The optimal parameters allowing maximising the energy efficiency factor were determined. Energy efficiency factors were obtained both on the crude material (size minus 2.8 mm) and on a sieved fraction (1-0.71 mm). They demonstrate that a low initial rate of breakage implies higher energy efficiency. On the contrary, conditions ensuring an initial maximal rate of breakage lead to an increase of the energy consumption.     

Effect of mill diameter on the rate of initial grinding in vibration ball mills

Vibration ball milling was carried out using three kinds of mills with the same internal volume but different diameters. The variations of specific surface area produced with time were investigated at a constant vibration intensity using feldspar with an initial size range of 74 – 149 μm. As a result, it was found that the specific surface area of product was markedly influenced by the difference in mill diameter even at the same vibrating conditions. According to an empirical equation proposed in a previous paper, the rate of initial grinding was also found to vary by a factor of 1.4 to 2.0, depending upon the mill used. The dependence of the rate of grinding on mill diameter can be explained by considering an effective area of mill shell capable of colliding with balls and a motion of balls in each mill. An available suggestion for designing a mill pot was obtained from this work.     

球磨机钢球充填率和级配对磷矿磨矿的影响研究

安宁矿业分公司为了改善磷矿磨矿产品的粒度组成,通过实验室实验对球磨机钢球充填率及级配进行研究,探究合理的钢球添加方案。结果表明,适宜的球磨机钢球充填率为38%,适宜的钢球级配为m(50mm)∶m(40 mm)∶m(30 mm)=30∶45∶25;适宜的钢球充填率及级配,能减轻矿石过磨,提高磨机效率和产能,节约钢球消耗量和药剂用量,为后续的选别作业提供合格的入选产品。     

研磨体质量对球磨机产质量的影响

0前言 长钢集团自筹资金2.2亿元,本着"世界先进,国内一流"的建设理念,于2003年8月建成当时在全国规模最大、设备最先进、自动化程度最高、环境优美的矿渣水泥生产基地--长钢集团瑞吕水泥有限公司.该生产线采用矿渣和熟料分别粉磨,再进行搅拌均化的生产新工艺,充分利用炼铁高炉废渣生产各种环保、绿色的水泥产品,减少了资源浪费和环境污染,获得良好的经济效益和社会效益.     

球磨机内研磨体运动轨迹的探讨

球磨机内研磨体的运动轨迹是合理设计磨机和指导磨机经济运行的理论基础。我国传统理论认为研磨体呈抛落状态运动时的运动轨迹为圆弧———抛物线。本文拟通过理论推导指出我国传统理论的缺陷,阐明同一层研磨体在上升过程中应以等速率运行,导出抛落状态下新的研磨体运动方程式,最后简要提出球磨机需要进一步探讨的几个问题,以期达到抛砖引玉的目的。1我国传统理论的主要缺陷我国传统理论对球磨机内研磨体运动的分析是建立在“5个基本假设”的基础上,将研磨体看成与其相邻的研磨体不相关的独立质点,运用运动学的知识进行推导的。它的几个重要…     

高效节能H型环球式磨机

阐述了环球式磨机的特点及研磨机制,通过各种磨机的性能比较,说明了环球式磨机各项运转参数的合理性及其独特的结构设计和正压运转系统。     

A comparison of dry and wet grinding of a quartzite ground in a small batch ball mill

Classical grinding models involve the selection function (S), which gives the rates of breakage of particles of each screen size fraction, and the breakage function (B), which describes the instantaneous size distributions of fragments produced when the particles of each fraction are broken. In order to investigate the differences between dry and wet grinding as far as the selection and breakage functions are concerned, batch grinding experiments were performed on both dry and wet bases, on the same material, a quartzite, in a small ball mill under similar experimental conditions.On a dry basis, the rates of breakage were found to be time invariant and independent of the size environment in the mill. It is logical to postulate a similar behavior for the breakage function. On a wet basis (65% solids), an increase of the rates of breakage was observed as grinding proceeds. This behavior is essentially due to the variation of the size environment within the mill. This increase in breakage rates was, however, less and less important as the particle size decreased and was not observed for the smallest particles tested. These points were confirmed by considering the disappearance kinetics of samples of different screen size fractions of quartzite injected in the mill during the batch grinding of a limestone. Moreover, it is not impossible that the breakage function could also vary with grinding time, giving rise to finer instantaneous size distributions of fragments as the size environment in the mill becomes finer. As an overall result, wet grinding has appeared more selective than dry grinding for coarse material, while it did not produce more schlamms.     

The effect of ball size on mill performance

The specific rates of breakage of particles in a tumbling ball mill are described by the equation S_i = ax^α_i(Q(z), where Q(z) is the probability function which ranges from 1 to 0 as particle size increases. This equation produces a maximum in S, and the particle size of the maximum is related to ball diameter by x_m = k₁d². The variation of a with ball diameter was found to be of the form a = k₂/d^1.5. Both k₁ and k₂ vary with mill diameter, and simple power laws have been assumed, k₁ ∝ D^0.1, k₂ ∝ D^0.6. If it is also assumed that the mean overall values of S_i for a mixture of balls is the weighted mean of S_i values for each ball size, equations are derived for calculating this mean value. As an example, the results are used in a mill simulation to show the quantitative effect of different ball mixes in a two-compartment cement mill versus a uniform mix over the whole mill.     

Constrained model predictive control in ball mill grinding process

Stable control of grinding process is of great importance for improvements of operation efficiency, the recovery of the valuable minerals, and significant reductions of production costs in concentration plants. Decoupled multi-loop PID controllers are usually carried out to manage to eliminate the effects of interactions among the control loops, but they generally become sluggish due to imperfect process models and a close control of the process is usually impossible in real practice. Based on its inherent decoupling scheme, model predictive control (MPC) is employed to handle such highly interacting system. For high quality requirements, a three-input three-output model of the grinding process is constructed. Constrained dynamic matrix control (DMC) is applied in an iron ore concentration plant, and operation of the process close to their optimum operating conditions is achieved. Some practical problems about the application of MPC in grinding process are presented and discussed in detail.     

半终粉磨系统双立磨配单球磨的改造尝试

针对立磨加球磨组成的半终粉磨系统中存在的电耗高的问题,提出了采用两台立磨配一台球磨机的生产工艺方案,通过改造立磨选粉机、调整磨内级配、增加空气输送斜槽等措施,实现了稳定生产、降低分步电耗、优化水泥颗粒级配的目标,水泥适应性明显好转。     

联合粉磨系统双立磨带单球磨的技术改造

介绍了2台CKP240立磨和2台Φ4.8 m×9.5 m球磨机的双闭路水泥联合粉磨系统,2018年、2019年在平均分步电耗较高的情况下进行提产改造,采用了双立磨带单球磨运行的工艺模式,既能保证灵活生产,提高运行效率,又能在提高台时产量的同时降低能耗。     

Kinetics of fine wet grinding in a laboratory ball mill

The kinetics of batch wet grinding of quartz from a feed of 600×425 μm to a product of 80% less than 8 μm have been determined using sieving and laser diffractometer sizing for size analysis. A dispersing agent was added while proceeding to longer grinding times to prevent particle agglomeration in the mill. The specific rates of breakage (S_i) values obtained were higher than those of dry grinding of quartz at the same experimental conditions, but the primary breakage distribution (B_i,j) values were the same. Non-first order grinding was observed with continued decrease of the specific rates of breakage for finer grinding. The simulations of the product size distributions were in good agreement with the experimental data, providing the decrease in rates was included.     

An analysis of fine dry grinding in ball mills

The kinetics of dry grinding of several cement clinkers and two coals were investigated in a laboratory tumbling ball mill. The kinetic process is first-order at first, but the rates of breakage decrease as fines accumulate in the bed. It was demonstrated that the slowing of the breakage rates applies to all sizes in the mill, indicating that the cushioning action of fines affects the whole breakage process, even though mill power remains constant. Tests on cleaning or non-cleaning the balls showed that the major factor was not the build-up of a coating on the balls. Radio-tracing tests showed that the effect was not due to pelletizing of fines into larger particles. The quantitative magnitude of the cushioning action was different for different materials. It is, therefore, postulated that cushioning is affected not only by air trapped in the bed of fine particles but also by the cohesive attraction of fine particles, which is a function of the material.     

闭路水泥磨研磨体级配的探讨

1有效装载量研磨体的装载量如何配合才能体现其有效性是,水泥工作者不断研究的课题配合好的装载量被称为。有效装载量有效装载量还可以这样描述当磨机钢,:球装载量近乎于台时产量的2倍时其钢球装载量即,被视为有效装载量换言之有效装载量的目标是使。,水泥磨装载量低于台时产量     

Effect of media size in stirred ball mill grinding of coal

As a prerequisite to producing super-clean coal with any physical coal-cleaning process, such as microbubble flotation, the feed coal must be micronized to liberate finely disseminated mineral matter. The stirred ball mill is regarded as one of the most efficient devices for micronizing coal. Using a 13.4 cm batch mill, the optimum operating conditions have been determined in terms of media size, feed size and media type. The rate of breakage determined with monosized feeds are compared on the basis of specific energy consumption. It has been found that a 20:1 ball size/particle size ratio gives optimum grinding conditions.     

提高湿法间歇球磨机研磨效率的探析

影响湿法粉磨研磨效率的因素很多,尤其是球磨机研磨体级配、填充率、装载量和分散剂品种及用量的不同,对台时产量及粉磨能耗有着明显的影响。笔者从研磨体级配、装载量、分散剂的类型等影响因素进行分析论述,提高研磨效率是企业提升效益的关键。     

Disturbance rejection of ball mill grinding circuits using DOB and MPC

Ball mill grinding circuit is essentially a multivariable system with couplings, time delays and strong disturbances. Many advanced control schemes, including model predictive control (MPC), adaptive control, neuro-control, robust control, optimal control, etc., have been reported in the field of grinding process. However, these control schemes including the MPC scheme usually cannot achieve satisfying effects in the presence of strong disturbances. In this paper, disturbance observer (DOB), which is widely used in motion control applications, is introduced to estimate the disturbances in grinding circuit. A compound control scheme, consisting of a feedforward compensation part based on DOB and a feedback regulation part based on MPC (DOB-MPC), is thus developed. A rigorous analysis of disturbance rejection performance is given with the considerations of both model mismatches and external disturbances. Simulation results demonstrate that when controlling the ball mill grinding circuit, the DOB-MPC method possesses a better performance in disturbance rejection than that of the MPC method.