共查询到20条相似文献,搜索用时 31 毫秒
1.
闭路粉碎流程稳态的循环收敛法计算 总被引:1,自引:0,他引:1
对由粉碎作业和分级作业构成的闭路粉碎流程,可用循环收敛法进行流程稳态的仿真计算。根据计算时预设条件的不同,循环收敛计算法可进一步分为恒定回路给矿量和恒定磨机给矿量的两种计算方法。本文讨论了这两种计算方法的原理和公式并给出实施这两种算法的详细步骤。 相似文献
2.
应用于粉碎过程的耐磨材料范围很广,本文考察的主要范畴是特殊钢种、非金属和合金白铸铁。确定了那些磨损最为严重的作业,并结合与磨损作用机理以及所采用的机械设备进行了讨论。本文着重论述一种材料——高铬白铸铁的冶金发展过程。这种材料在耐磨方面的主要物理性质与其化学成份和微观结构有关。本文引用一系列涉及磨矿过程的具体应用,论证了利用此种合金所得到的成功应用和经济效益。通过强调将易磨损零部件的成本降至最低,使读者对正在进行的高铬铸铁发展的研究与实践有个深入的理解。 相似文献
3.
用浮选法回收复杂硫化矿石中的矿物时,一般是高密度矿物的冶金回收率比低密度矿物低。例如,在Ag—Pb—zn一脉石系中,细粒的银和铅矿化物的回收率很低。当这些矿石的磨矿在以旋流器为分级设备的闭路流程中进行时,情况更是如此。当矿物粗粒嵌布时,由于旋流器的作用,大密度的矿物会产生过磨。循环负荷通常很大,导致重矿物过磨。本文提出了一种分析一般磨矿流程的方法,该法也适用于改进的流程,流程的改进是把一排单元浮选槽引入磨矿回路,目的是浮出一种或几种矿物。文中提出的方法,利用磨矿—分级—浮选的动力学模型。计算了分级和浮选过程的冶金回收率。还计算了过程的其它参数,并与模拟普通磨矿流程所得的数据作了比较。按迭代算法建立了数字模拟程序,为了模拟能再现工业生产的实际情况,程序中把磨矿、分级和浮选的模型组合起来。 相似文献
4.
5.
6.
7.
磨矿回路存在多变量、强耦合、严重非线性以及时变等综合复杂特性,难以采用常规控制方法对其进行有效控制。基于事例推理技术,提出了闭路磨矿回路的智能多变量控制方法,用于对过程控制系统的设定值进行调节。通过各控制回路跟踪调整后的设定值,实现磨矿粒度的闭环控制。经过在某选矿厂的工业应用表明了所提方法的有效性。 相似文献
8.
根据首钢矿业公司大石河铁矿选矿车间1段闭路磨矿筛分分级返砂物料组成进行磁选试验,在127.39 k A/m的磁感应强度下,返砂磁选抛尾作业产率为31.64%,通过建立生产系统返砂磁选平衡状态下的数学模型,对返砂磁选抛尾工业应用进行预测。根据首钢矿业公司大石河铁矿选矿车间的生产数据,预测在增加返砂磁选抛尾作业后,选择返砂比为60.94%时,返砂磁选作业尾矿产率为18.75%,可增加1段球磨机新给矿处理能力20.36个百分点。返砂磁选抛尾可显著提高磨机生产能力,对矿山节能降耗、降低成本具有重要指导意义。 相似文献
9.
在超细粉碎过程中研磨时间与粒度的关系初探 总被引:7,自引:1,他引:6
在超细粉碎试验研究过程中,通过按不同的研磨时间取样,对所取样品进行粒度及粒度分布的测定,以及对所测数据的整理,可得出一定的规律。 相似文献
10.
11.
V. HasanzadehA. Farzanegan 《Minerals Engineering》2011,24(5):424-432
Mathematical modeling and simulation techniques are widely used to design and optimize comminution circuits in mineral processing plants. However, circuit performance predictions are prone to errors due to inaccurate calibration of models used in simulations. To address this problem, the authors applied a method based on genetic algorithms (GA) for estimation of HPGR (high pressure grinding rolls) model parameters. In this research, a simulation algorithm was developed and implemented in MATLAB™ based on published HPGR models to test and demonstrate GA application for model calibration. The GA toolbox of MATLAB was used to obtain the optimal values of HPGR model parameters. The authors successfully validated simulator predictions against HPGR data sets at laboratory and industrial scales. The results indicate that GA is a robust and powerful search method to find the best values of HPGR model parameters that lead to more reliable simulation predictions. 相似文献
12.
This paper describes a methodology to monitor axial mixing in an IsaMill as a function of mill feed flow rate, mill tip speed and media load. Steady state temperature measurements (profiles) along the mill length were used to quantify the degree of mixing during the comminution process. Combined mass and energy balances across the mill length were done to develop a predictive model for slurry mixing in the mill. The temperature measurements can be used for IsaMill control and optimisation. 相似文献
13.
The need for an accurate and comprehensive understanding of load behaviour in industrial mills is outlined, and the implications of the availability of techniques for measuring load behaviour in these mills for both design and control is explored. Some research performed on a pilot mill used to investigate the effect of grid liners on autogenous milling is described. Considerable slip between liners and load occurred, with the result that a simple torque model (taking into account the orientation of the load and the slurry pool as measured by conductivity probes passing through the mill shell) was adequate for describing mill power at high mill speeds. The different behaviour of overflow and discharge mills as affected by slurry and load volume was explored. Some work involving the measurement of the axially distributed behaviour of the load in an industrial mill is then described. Liner movement, load orientation (measured with conductivity probes) and load temperature were measured as a function of axial position. The load orientation was found (surprisingly) to be almost independent of axial position but was a strong function of load volume. The axial temperature profile correlated in a logical fashion with other operating conditions. The relevance of these measurements for mill control is explored. 相似文献
14.
This paper focussed on investigating the effects of chamber diameter and stirrer design on cement grinding performance of a horizontal type dry stirred mill. Within the scope, pilot scale test works were undertaken with two different chamber diameters (20.4 cm and 26.4 cm) having the same length and three different stirrer designs (wing, cross and disc) having the same diameter (16 cm). The chamber diameter tests were performed at the same stirrer design, media size and media filling. The studies concluded that, the use of larger chamber improved the grinding efficiency since 31.8% and 35.8% less energy was consumed than the smaller mill at the RRd50 of 1.41 and 1.66 respectively. This behaviour of the larger mill can be attributed to the increased gap distance between the chamber wall and stirrer edge. With regards to stirrer design, the statistical evaluations, grinding results and temperature measurements all indicated that the disc design of stirrer ground the particles more effectively at high energy levels (>40 kW h/t). The use of the disc design reduced the energy consumption by 21% (at RRd50 of 3.5). This was attributed to dissipation of energy as heat since the temperature measured for the wing and cross types were higher than the disc type. 相似文献
15.
高压辊磨机在矿物加工领域的应用 总被引:13,自引:1,他引:12
结合国内外一些典型的工业实例,从金刚石矿粉碎、铁矿石加工、有色和贵金属矿石粉碎3方面综述了高压辊磨机在矿物加工领域的应用进展和现状,并分析了高压辊磨机在矿物加工领域的发展趋势。 相似文献
16.
刘建远 《有色金属(选矿部分)》2016,(5):66-72
从高压辊磨机在矿石碎磨工艺流程中的地位及所起的作用角度综述此设备在矿物加工领域的应用现状和潜力,展望未来的发展前景及面临的挑战。 相似文献
17.
搅拌磨超细粉碎工艺的研究 总被引:3,自引:0,他引:3
介绍了搅拌磨超细粉碎的工艺过程和助磨剂对超细粉碎效果的影响。探讨了搅拌磨超细粉碎的行为特征。研究表明,用搅拌磨可制得平均粒径小于1μm的超细滑石粉,工艺简单,效率高,产品无污染;助磨剂主要是通过与滑石粉的吸附作用,降低矿浆粘度,提高磨矿过程的分散性而产生助磨作用; 相似文献
18.
Stirred mills are becoming increasingly used for fine and ultra-fine grinding. This technology is still poorly understood when used in the mineral processing context. This makes process optimisation of such devices problematic. 3D DEM simulations of the flow of grinding media in pilot scale tower mills and pin mills are carried out in order to investigate the relative performance of these stirred mills. Media flow patterns and energy absorption rates and distributions are analysed here. In the second part of this paper, coherent flow structures, equipment wear and mixing and transport efficiency are analysed. 相似文献
19.
The technique of developing curves of how the operation and product of a mill responds to a change in one of the prime operating variables is presented. This has been investigated to the great benefit of research into the comparison of mill performance when an operating parameter of interest is changed. These ‘grindcurves’ can be used to select the correct conditions for meaningful comparative tests. It is shown that the conclusions drawn from pilot work can be totally changed by shifting the mill to operate under optimal conditions for the comparison. The use of the technique in quantifying SAG mill performance is demonstrated. 相似文献
20.
P. Radiszewski 《Minerals Engineering》1999,12(12):1501-1520
In comminution research, recent trends have been made to describe internal dynamics of mills using the discrete element method (DEM). In this work, three modelling approaches to DEM implementation to charge motion modelling are compared these being single ball trajectories, system of individual balls describing the mill charge and charge balls grouped together using an arbitrary discretization scheme. After presenting some charge motion fundamentals as well as a presentation of the three approaches to DEM implementation, charge profile results are presented for a 12 m mill. Further power predictions for a number of ball mills are presented along with a brief internal charge dynamics comparison. A discussion focuses on the needed future research to improving these approaches. 相似文献