半自磨设计趋势-经济比较-磨机规格和传动方式

从当今应用的各种半自磨机结构和传动方式方面论述了半自磨机设计的发展趋势。确认了这些结构和传动方式对投资和生产费用的影响 ,并评述了关键的技术问题。所讨论的内容是基于传统的北美“偏平型” 磨机。     

半自磨设计趋势—经济比较—磨机规格和传动方式

从当今应用的各种半自磨机结构和传动方式方面论述了半自磨机设计的发展趋势。确认了这些结构和传动方式对投资和生产费用的影响，并评述了关键的技术问题。所讨论的内容是基于传统的北美“偏平型”磨机。     

半自磨设计趋势,经济分析,磨机规格和驱动装置

本文评述了目前应用的各种半自磨机结构设计和驱动装置选择的趋势，评估了这些选择对基本投资和操作成本的影响，介绍了关键的技术要点，本文的讨论以北美常用的“扁平式”磨机结构为基础。     

半自磨机传动方式的选择

磨矿是磨矿回路中的主要作业。近20年来,大直径半自磨机(SAG)成为优先选用的第一段磨机。随着磨机规格增大,传动系统变得更复杂,同时也积累了半自磨机运行和设计方面的经验。动力电子装置的高度可靠使半自磨机运行具有灵活性,可以满足降低生产费用之要求。以前大多数半自磨机是恒速运行的。现在由于使用交流同步电机或直流电机,半自磨机能以恒速或变速运行。但是这种灵活性     

自磨、半自磨机的选择与设计

在研究使用自磨或半自磨可能性的时候,生产厂家和工程公司经常需要在三个方面取得磨机制造厂的协助:对特定矿石使用自磨或半自磨是否适合的研究介绍;完成所要求磨矿的磨机尺寸;关于磨机设计和操作的介绍等等。棒磨和球磨机可以借助于小型的标准可磨性试验和所确定的计算程序进行选择,其中最常用的是邦德(Bond)可磨性试验和邦德功指数方程进行计算。它们的准确性可见本文作者罗兰的文章。该文介绍了根据工厂实践数据计算出来的和试验室可磨性试验得到的功指数之间的关系。     

关于“磨机中介质磨损的矩阵模型研究”一文的商榷

关于“磨机中介质磨损的矩阵模型研究”一文的商确在阐述了磨机稳定工作状态概念的基础上，着重论述了建立介质稳定磨损矩阵模型的前提条件，以及该矩阵的不可传递性和不可叠加性     

关于半自磨机磨矿产品传递粒度(T80)的讨论

半自磨—球磨流程在选矿厂粉磨工艺中占有重要地位,随着矿石品味的下降和选矿厂单系列生产线产能越来越大,半自磨—球磨工艺应用越来越广泛。在项目前期方案设计和后期实际生产过程中,半自磨回路的产品传递粒度(T_(80))都是重要的工艺参数之一,直接影响了半自磨回路和球磨回路的运行状态,进而决定了半自磨回路和球磨回路之间的负荷分配。结合半自磨—球磨的生产运行数据,进一步对该流程进行数学分析和理论预测,讨论了设备结构和矿石性质等因素对T_(80 )的影响,并进行了数据分析,针对不同状况提出了相应的调整优化措施,为后续新项目方案设计和旧项目改造方案的制定和优化提供技术支撑。     

单段半自磨与半自磨+球磨流程的兼容设计和关键因素分析

针对单段半自磨流程在国内应用较少与经验不足等问题,以巴西某金矿项目为例,结合项目前期采用单段半自磨流程,后期采用半自磨+球磨流程达到产能翻倍的特点和要求,系统分析了影响单段半自磨流程的选型设计、运行工况和磨矿性能的4个关键因素,重点讨论单段半自磨流程设计的关注点和解决措施,为项目达产达标提供可靠保证,也为广大工程技术设计人员提供参考。     

关于提高半自磨机产能方法的实践和探讨

近年来,随着矿山规模化、大型化、环保等需求,半自磨机逐渐成为选矿厂的主流磨矿设备,但是,由于半自磨机本身的碎磨特点,对矿石性质的敏感程度高于常规碎磨及高压辊磨等系统,所以,半自磨机如何做到达产、稳产、增产是矿山不断摸索和实践的重要环节。本文通过对某选矿厂?7.5 m×3.2 m半自磨机无法达产的原因进行分析及改进,提出了提高半自磨机产能的多种方法,并进行了对应的评价,以供同类矿山遇到此问题时参考。     

一种半自磨机出料端衬板的优化设计

阐述了矿用半自磨机出料端衬板的结构对磨机处理量的影响,分析了现有半自磨机出料端衬板存在的弊端,提出一种全新的半自磨机出料端衬板结构,并利用离散元分析软件对优化设计前后的出料端衬板结构进行模拟对比。结果显示,优化后的出料端衬板的提升物料能力大大加强,极大地提高了磨机生产效率。     

半自磨机简体衬板结构设计比较

作为易损件的磨机衬板,在满足产量、节约功耗的前提下,增加衬板的寿命一直是设计的重点.针对某半自磨机的筒体衬板设计情况,通过MillTraj软件模拟了初设衬板的钢球轨迹模型,优化了衬板截面参数,同时论述了不同筒体衬板形式的结构特点,为半自磨机衬板的结构优化设计提供了参考.     

Inferential measurement of SAG mill parameters II: state estimation

This paper discusses the combined state and parameter estimation of SAG mill inventories and model parameters. Recognised simulation models are utilised for the rock and water charge state equations. New models of the ball charge and mill shell lining states are presented. The 36 state system is detectable although not completely observable. Five ore grindability and mill discharge grate parameters augment the state system. One mill weight and two discharge measurement models are presented and utilised in two state estimation formulations. Results indicate that a size by size SAG mill discharge measurement model provides superior state estimates and improved discharge grate parameter estimation compared to a bulk SAG mill discharge measurement model.     

Inferential measurement of SAG mill parameters V: MPC simulation

This paper discusses a case study application of inferential measurement models for semiautogenous grinding (SAG) mills and is the last in a five-part series on Inferential Measurement of SAG Mill Parameters. Inferential measurements of SAG mill discharge and feed streams and mill rock and ball charge levels, detailed earlier in the series, are utilised in a simulation environment. A multi-variable, model predictive (MPC) controller simulation is developed from plant data and utilised to investigate the potential of utilising the inferential models in a mill charge control strategy. An operating curve is generated and discussed in terms of possible utilisation in conjunction with an MPC controller. The results are encouraging and potential avenues for further research are discussed.     

Inferential measurement of SAG mill parameters III: inferential models

This paper discusses the combined state and parameter estimation of SAG mill inventories and model parameters. Recognised simulation models are utilised for the rock and water charge state equations. New models of the ball charge and mill shell lining states are presented. The 36 state system is detectable although not completely observable. Five ore grindability and mill discharge grate parameters augment the state system. One mill weight and two discharge measurement models are presented and utilised in two state estimation formulations. Results indicate that a size by size SAG mill discharge measurement model provides superior state estimates and improved discharge grate parameter estimation compared to a bulk SAG mill discharge measurement model.     

半自磨机筒体衬板结构的模拟优化研究

在磨矿工艺中,半自磨机筒体衬板的结构型式对磨机效率与矿山开采成本有着重要的影响.采用离散元模拟方法,研究了半自磨机筒体衬板排数对磨机效率的影响,得到了半自磨机筒体衬板周向排数的设计方法;分析了半自磨机不同仓位筒体衬板的使用工况与磨损规律,设计出了沿筒体长度方向上变截面的筒体衬板结构,有效延长了衬板寿命;通过分析筒体衬板面角对磨机生产效率与衬板寿命的影响,设计出了变面角筒体衬板结构,兼顾了磨机效率与衬板寿命两个重要使用指标.     

Further validation of DEM modeling of milling: effects of liner profile and mill speed

Grinding mills are usually lined with lifters to improve their efficiency. During the course of operation, the lifters are worn away. This will affect the energy efficiency and capacity of mills and the behavior of the load in the mill and finally leads to a relining to replace the worn lifters. However, the effects of the profiles of lifters are not taken into account in all the previous power models for rotary mills. Discrete element method (DEM) is capable of demonstrating the effects of lifter profiles on mill power and load behavior. In this paper, two types of lifter profiles, square and trapezoidal, are investigated in terms of mill power and load behavior with a 2D mill and a DEM simulator, Millsoft, over a wide range of rotational speed. DEM satisfactorily predicted the load behavior and power draw for different lifter profiles at sub-critical speeds comparing with the experimental results. It is found that the trapezoidal lifters draw more power than the square lifters. An attempt has been made to explain the difference between measured and simulated power using photographs of experimental load behavior.     

大型半自磨机筒体衬板改型优化的研究与应用

对国内大型半自磨机筒体衬板的使用情况进行了调研,结合伊春鹿鸣矿业有限公司的生产实际和筒体衬板的失效形式,确定了半自磨机筒体衬板改型优化研究的重点方向。采用基于离散单元法的半自磨机介质冲击能量分析和基于Milltraj的半自磨机介质抛落轨迹计算技术,对半自磨机筒体衬板进行了改型优化,经过实际生产应用,取得了良好的效果。     

The relationship between charge shape characteristics and fill level and lifter height for a SAG mill

A predictive model that allows mill fill level and the lifter height to be determined from measurements of the head, bulk and impact toe positions for a generic SAG mill has been developed using data from a series of three dimension DEM simulations. A Design of Experiment (DOE) approach is used to define a series simulation conditions with the two factors being the lifter height and the fill level. The charge structure is characterised by the locations of the head, shoulder, bulk toe and impact toe. These are determined by visual analysis of the particle trajectories. The spatial variation of the liner pressure distribution can provide valuable information on the structure of the charge. This was found to vary systematically with lifter height and fill level. The relationships between the visual key locations and the key features of the pressure distributions were identified and found to be well described by linear equations. Finally, parametric models are fitted to the DEM data for both the lifter height and fill level allowing them to be estimated from measurements of the key charge locations. These could be used as part of a control strategy for the mill and/or to assist with re-line scheduling.