影响半自磨机顽石产率的因素研究

半自磨机在生产过程中会产生大量顽石,顽石在磨机内累积会影响磨机的产能及磨矿单位功耗。通过分析某铜矿半自磨机3个月的生产数据,研究给料粒度分布及磨机转速对顽石产率的影响,总结出如下规律:半自磨机给料粒度的稳定性和配比对顽石产率均有影响,当半自磨机给料粒度稳定,粒度分布合理,特别是超大粒度矿石分布合理时,半自磨机顽石产率高;半自磨机转速与顽石产率呈正相关,半自磨转速增大,加快了磨机的排矿能力,顽石产率高。针对此种规律,给出了现场半自磨机调节建议。     

基于离散元法的半自磨机磨矿过程的仿真研究

通过离散元软件EDEM建立了半自磨机仿真试验模型,并对其磨矿过程进行了模拟,分析了不同转速、衬板个数及衬板高度对半自磨机有效功率的影响。结果表明,随着转速率和衬板的增加,半自磨机的有效功率成线性增加;不同衬板高度对半自磨机有效功率的影响不同;随着L/H的变化,半自磨机的有效功率不断变化,在L/H=5左右,半自磨机的有效功率趋于最大值。可为半自磨机运行参数的选择提供一定的参考依据。     

自磨机给料粒度组成对自磨机产量的影响

湿式自磨机产量的高低取决于许多因素。在矿石性质、磨机规格和型号既定的条件下,自磨机的产量及效率取决于适宜的操作条件,例如,料位、磨矿浓度、磨机内部及产品的粒度特性、给料粒度组成、是否添加磨矿介质及流程结构等。本文仅就给料粒度组成的变化对自磨机产量的影响,进行一些探讨。关于自磨机给料粒度组成对自磨机产量的影响,有人作过系统的研究。例如,瑞典有色金     

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.     

湿式自磨机合理长径比的探讨

本文针对目前世界上使用的两种不同长径比的湿式自磨机进行分析,论述了由长径比不同所引起的对磨矿效果的影响;探讨和阐明了长径比对磨机造价及衬板磨损等方面的影响关系。认为长径比为0.5～1.0的“中短筒”自磨机是合适的,并对国内湿式自磨机设备型谱提出初步建议。     

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。     

给料粒度分布对半自磨机的影响

给料粒度分布是影响半自磨机运行的重要因素,但由于各种因素制约,各选厂对粒度分布对半自磨机影响的研究较少。基于福建某铜矿半自磨机给料输送带在线粒度检测系统的数据,通过分析半自磨机给料粒度与其处理量及单位功耗的关系,总结出以下规律:给料粒度分布稳定且合理,则磨矿效率高,产能大,能耗低;给料粒度分布波动大,特别是超大块分布不合理,则产能相对较低,能耗相对较高。针对此规律,给出了现场半自磨机给料粒度的调节建议。     

基于TRIZ理论的半自磨机衬板设计研究

磨机筒体衬板结构影响着磨机的工作效率,同时对衬板寿命也有一定的影响。运用TRIZ理论对衬板结构进行系统分析和创新设计研究,提出了半自磨机衬板变截面、不等厚、双金属复合、分体式衬板等结构的设计方案,并取得实践应用,其分析方法可用于指导半自磨机衬板结构的优化设计。     

湿式自磨机产量与产品粒度的回归模型及技术经济评价

影响湿式自磨机生产指标的因素很多。在给矿特性、磨机负荷和操作条件等既定情况下,不同工艺流程对自磨机产量及其技术经济效果,产生重大影响。本文试图就三种不同流程结构的自磨机工业试验结果,对产量(给矿速率)与细度(产品粒度)之间的变化特性,进行数理分析,求出一定工艺范围内的回归模型。用函     

高压辊磨机作为顽石破碎机的研究

在矿石硬度较高的矿山,应用自磨/半自磨工艺时,普通的圆锥破碎机作为顽石破碎机因破碎粒度太大,会导致部分大颗粒顽石在磨机内累积,影响磨机产能。针对该问题,研究了高压辊磨机作为顽石破碎机的优势及可行性,介绍了高压辊磨机作为顽石破碎机的主要工艺,并给出了使用中需注意的问题。实际应用证明,使用高压辊磨机作为顽石破碎机可以降低返回磨机的顽石粒度,提高磨机的处理能力,降低磨机功耗。     

广义磨在火电行业的应用优势分析

随着我国国民经济的高速发展,对电力的需求日益增加,根据我国资源情况,目前火力发电仍占主导地位。在火电厂中,有三种主要物料需要粉磨：一是火电厂的主要燃料煤;二是脱硫用的石灰石;三是煤燃烧后的粉煤灰。下面对作为专利产品的广义磨系列设备粉磨上述三种物料的适应性进行分析。     

高压辊磨+搅拌磨在某复杂难选铁矿石选别工艺中的优越性研究

为了验证在某复杂难选铁矿石的选矿工艺中,应用高压辊磨机和立式搅拌磨的优越性,进行了一系列对比试验。结果表明,与颚式破碎机相比,高压辊磨机产品的粉矿率更高,产品的可磨性更好;与球磨机相比,立式搅拌磨机细磨效率更高、效果更好,相同磨矿细度下,立式搅拌磨机磨矿产品的解离度更高,磁选铁精矿品位也更高;高压辊磨+立式搅拌磨在处理复杂难选铁矿石方面具有显著的优势。     

高效节能磨矿设备综述

着重阐述高效节能球磨机、高压辊磨机、塔式磨机和离心磨机的结构特点和应用效果。     

基于DCS采集的振动数据的磨机负荷分析

检测磨机负荷可了解磨机运转状况以指导生产。以国内某铜矿的半自磨机为研究对象,分析分布式控制系统(DCS)采集的磨机轴承座振动数据和磨机负荷之间的关系。基于主成分分析(PCA)方法从功率和电流数据中提取特征作为负荷参照指标,采用快速傅里叶变换(FFT)方法分析振动信号频谱,通过回归分析与假设检验,验证特定振动传感器的二倍转频频谱与负荷参照指标正线性相关,由此可以用振动传数据的二倍转频频谱表征磨机负荷。     

Measurement system of the mill charge in grinding ball mill circuits

Investigation of a dry fine grinding circuit has shown significant influence of the mill load (powder filling) on the production capacity. To improve the circuit performance at industrial scale, alternative ways of mill load measurement were investigated. Detection of strain changes in the mill shell during mill rotation, by using a piezoelectric strain transducer, provided very interesting results, allowing evaluation of the weight of the mill charge and control of the powder filling to obtain an optimal level. Power draw has thus been increased by about 5% compared to the old configuration where mill motor power input was used to control the mill charge. By measuring mechanical vibration with the transducer, additional useful information has been obtained about the behavior of the cataracting and cascading balls inside the mill shell. Finally an important factor was simplicity and low investment cost of the total installation, as many fine grinding mills operate in relatively small circuits that do not warrant large investment for alternative measurement methods.     

Control of the mill charge behavior in dry tumbling mills

Powder filling of a dry mill has a large influence on grinding capacity and wear rate of grinding media and liners. In particular low powder filling levels can cause extensive wear rates. This paper discusses the influence of some operating parameters of the mill circuit on powder filling, when airflow through the mill is applied. An method of warning against low powder filling levels inside the mill is shown, a piezoelectric strain transducer installed on the mill shell accomplishing this task.     

Use of temperature for diagnosing mixing in the IsaMill

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.     

Modeling of energy loss to the environment from a grinding mill. Part II: Modeling the overall heat transfer coefficient

The objective of the paper is to develop a model for the overall heat transfer coefficient as a function of the load volume, mill speed, and the design of the mill liners and shell, using the energy balances in order to model energy loss form the grinding mill. The energy loss via convection through the mill shell is accounted for by quantifying the overall heat transfer coefficient of the shell.     

Effect of cone-lifters on the discharge capacity of the mill product: Case study of a dry laboratory scale air-swept ball mill

The common use of air-swept ball mills in coal power plants is largely attributed to the ease of discharge of the pulverised coal by entrainment in the air stream passing through the mill. The efficiency of mill product discharge (which determines the capacity of the power plant), depends on the mill design and operating conditions. Presented in this paper is an investigation of the effect of liner/lifter profile on the discharge capacity of the mill product. The focus is on assessing the improvement in product discharge rate achievable by retrofitting worn liners with cone-lifters. The cases investigated were (i) bevel (45°, face angle) and (ii) bevel (45°, face angle) modified with cone-lifters. The discharge rate of the mill product was found to be 100% higher in the latter than in the former case. It is postulated that the ‘raking’ action by the cone-lifters helped to mix the load as a whole, which ensured fine particles are more exposed to the classifying air. This presumably enhanced the pre-classification efficiency inside the mill, thereby resulting in more fines removal from the mill. Further analysis was performed to assess the efficiency of particle discharge from the mill for different size classes, using an empirical equation, which is based on mass-size balance of material inside the mill and that discharged.     

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