落重试验测定内蒙古某铅锌矿石粉碎特性参数

通过标准落重试验和磨剥试验对内蒙某铅锌矿石进行了磨矿特性参数测定,测定结果表明,该矿石属于中软矿石,在试验粒度范围内(13.2~63mm)矿石抵抗冲击粉碎的能力随颗粒粒度的减小而增大。这些矿石特性参数为此铅锌矿132万t/a选矿厂碎磨流程的"半自磨-球磨"方案进行流程模拟和磨机选型提供了依据。     

落重试验测定矿石粉碎特性参数

为了科学、准确地进行碎磨设备选型,并确定合理的碎磨工艺流程,对国际上较盛行的自磨/半自磨工艺中物料粉碎特性参数的测定方法——JKTech落重试验法进行了系统介绍,在此基础上,采用JK落重试验仪和磨蚀粉碎试验设备,测定了承德某铁矿3个矿样的冲击粉碎参数A和b以及磨蚀粉碎参数Ta。将试验结果与数据库数据比较,可以得出:13个矿样的粉碎特性十分接近,都属于软-中软矿石。2矿样在破碎能为2.5、1.0 kWh/t时,颗粒的抗冲击破碎能力随颗粒粒度的增大而下降,且破碎能越大颗粒抗冲击破碎的能力下降越显著;当比破碎能为0.25kWh/t时,颗粒的抗冲击破碎能力随颗粒粒度的增大而上升,即随比破碎能下降,颗粒粒度-t10关系曲线的斜率变小。3试验结果可以成功用于磨机与破碎机处理量和能耗的计算以及自磨/半自磨流程设计和模拟计算。因此,JKTech落重试验所测得的粉碎特性参数不仅可以判断矿石性质,也可作为设备选型和流程确定的依据。     

粒度小于13.2 mm矿石颗粒的冲击粉碎试验研究

JK落重试验是测定矿石粉碎特性参数的一种方法。标准落重试验的试样粒度范围为-63.0+13.2 mm。在利用JKSim Met软件进行自磨/半自磨粉碎模拟时,由此试验获得的矿石特性参数被默认地运用于所有粒度颗粒的粉碎。以华东某金矿矿石为对象,进行了粒度小于13.2 mm矿石颗粒的冲击粉碎试验研究。结果表明,此矿石物料的粉碎存在粒度效应,随着粒度的减小,颗粒抵抗冲击粉碎的能力增大。另外还发现,试料制备时的破碎次数对颗粒的粉碎效果也有影响。     

关于矿石粉碎特性参数及其测定方法

从粉碎工艺设计应用的角度,综述各种表征矿石粉碎特性的物料参数及其测定方法,包括用于传统碎磨设备选型计算的物料参数及其测定方法、用于自磨/半自磨流程设计的物料参数及其测定方法,以及用于高压辊磨流程设计的粉碎试验方法。     

SCSE——表征矿石半自磨可磨度的新指标

JK落重试验及SMC试验作为测定矿石粉碎特性的试验方法在半自磨机选型和工艺条件优化中得到越来越多的应用。由JK落重试验或SMC试验获得的物料特性参数A和b是一种建立在特定粉碎数学模型基础之上的模型参数,这两个参数本身没有明确的物理意义,尽管其乘积A×b可作为衡量矿石抵抗冲击粉碎能力的一个指标,但A×b取值大小的工艺意义只有通过模型计算结果才能体现出来。为弥补这方面的不足,JKTech公司和SMCT公司新近联合推出了一种表征矿石半自磨可磨度的新指标——SCSE值。在综述JK落重试验、SMC试验以及利用JKSim Met软件进行半自磨磨矿流程模拟的方法和原理的基础上,介绍了这个新指标的定义、意义及局限性。     

白马钒钛磁铁矿破磨参数测定

系统测试了白马钒钛磁铁矿各类型矿石的破磨参数，这些参数反映了该矿石的碎磨特性；原生矿石具有较强自生介质能力，可开展自磨半工业试验。为消除风化矿的影响，对该矿石进行自磨矿碎磨工艺的研究是必要的。     

自磨技术的发展及其有关总是的评述（之二）

5　有关问题的评述5 1　关于自磨与常规磨矿与常规碎磨流程比较 ,自磨的主要优点是 :能接受较大的给矿粒度 (最大粒度一般为 3 50～ 2 0 0ｍｍ ) ,因此可以取代中、细破碎及粗磨作业 ,减少生产环节和粉尘污染 (对湿式自磨 ) ,简化车间组成和占地面积 ;具有一定的选择性碎磨作用 ,减少矿石过粉碎 ,有利于分选 ;不耗或少耗磨矿介质 ;对含水含泥较多的粘性矿石采用湿式自磨可以避免常规流程中破碎、筛分等环节的堵矿问题。自磨流程的主要缺点是 :电耗一般比常规磨矿高 ;设备作业率比球磨低 ;对给矿粒度及其可磨性变化比较敏感 ,生产易波动 ,操…     

电磁波预处理对黄铁矿碎磨经济性的试验分析

为解决当前传统碎磨流程能耗高、效率低的问题,并结合电磁波选择性、整体性、高效性的加热特性,试验探究经不同时间电磁波预处理后的矿石进行破碎、磨矿过程中产量、能耗、粒度及效率等经济性指标的变化。试验结果表明,电磁波作用能够有效提高破碎产量,而产品粒度不受影响;能够有效降低磨矿产品加权平均粒度,降低磨矿时间。将矿石置于输出功率为800 W的电磁波场中预处理180～240s,能够有效提高碎磨产量及效率,降低流程能耗。如电磁波预处理240s时,比未预处理的碎磨流程节能5.96%,破碎产量提高57.84%,磨矿产量提高26.23%,碎磨经济性显著提高。     

基于机器视觉的矿石块度智能识别及应用

给矿粒度特性以及矿石可磨性对半自磨过程的影响远大于常规碎磨流程,通过对给矿皮带上矿石图像进行矿石粒度特性分析,可从给矿源头上实现矿石块度实时检测。基于多尺度的矿石图像分析系统,实时采集半自磨给矿矿石图像,通过图像处理技术,实现矿石块度有效分割以及粒级统计,为半自磨给矿矿石块度控制提供数据支撑。     

大红山铁矿石自磨试验研究

以大红山铁矿石自磨介质适应性试验和半工业试验结果为依据,对自磨介质功指数、NORM基准数和流程试验结果进行了分析和讨论,结果表明,对大红山铁矿石可采用全自磨或半自磨,但采有半自磨,但采用半自磨工艺更为合理。     

基于矿物学特征的磁铁矿石破碎解离预测研究

为研究矿石矿物学特征对破碎后矿物解离程度的预测机制,以水厂铁矿沉积变质型磁铁矿石为研究对象,采用偏光显微镜观测矿石结构、构造与粒级组成,对比冲击破碎与二段磨矿产品的品位特征,分析磁铁矿石的破碎性质,预测矿石破碎后不同粒度范围下矿物颗粒的解离程度。结果表明,水厂铁矿磁铁矿石的结构构造简单,破碎过程中易产生沿晶断裂,冲击破碎至嵌布粒度的磁铁矿颗粒解离程度高于二段磨矿后磁铁矿颗粒的解离程度。矿石结构与构造特征可以反映矿石破碎与矿物解离的难易程度,通过分析磁铁矿石原矿矿物的粒级组成,可以有效预测矿石破碎后不同粒度范围内的矿物解离程度。研究结果丰富了矿石碎磨特性的分析方法,为矿山改进矿石加工工艺、实现节能增效提供了理论依据。     

The effect of breakage method on the shape properties of an iron-oxide hosted copper–gold ore

Using a mineral liberation analyser (MLA), the shape properties of an iron-oxide hosted copper–gold ore following comminution in either a hammer mill or a piston–die compression unit were examined. It was found that particle angularity distributions were able to be fitted to the beta distribution, providing a convenient way to quantify changes in particle shape properties as a function of the breakage method employed. Particles discharged from the hammer mill were less angular than particles discharged from the piston–die compression unit. This was attributed to attrition breakage mechanisms, whereby topographical features are chipped off parent particle surfaces. The results suggest that the quantification of shape properties is a convenient method for obtaining insight into the nature of breakage events that take place inside comminution devices.     

碎磨工艺现状及发展趋势

碎磨工艺是后续选冶工艺的准备过程或准备作业,必须满足选冶工艺对矿石处理的粒度要求,使矿物充分地单体解离才能获得高质量的选冶产品和高指标。碎磨产品质量直接影响到选矿指标和生产成本,是选矿厂的重要组成部分。本文通过分析选矿厂碎磨工艺流程现状,指出了存在的主要问题:碎磨流程试验研究重视程度不足、建设投资和生产能耗高;噪音和粉尘大污染环境等。针对这些问题,探讨了碎磨工艺有效的应对措施,以满足选别对产品粒度更严格的要求,适应节能、环境、操作更苛刻的条件,并对未来碎磨工艺发展趋势进行了展望。     

Fractal evaluation of particle size distributions of chromites in different comminution environments

Particle size distributions (PSDs) are often rendered as cumulative functions, either as number of particles larger than a certain diameter, or as mass smaller than a certain diameter. The fractional exponent of the number/mass-size power law has been interpreted as the fractal dimension of the distribution. An application of PSD in comminuted chromites by means of the fractal mass distribution is presented. The five types of chromite samples were subjected to four comminution events; jaw, cone, hammer crushing and ball milling. The PSDs generated by different comminution devices has been evaluated by mass-based fractal fragmentation theory and the fractal dimensions of fragmentation (D_F), a value quantifying the intensity of fragmentation, have been obtained for each chromite ore. The results of the present study show that the particle size distributions of the comminuted chromites having different mineralogical characteristics are fractal in nature. Single and multifractal methods have been successfully applied to characterize particle size distributions (PSD) of chromite samples comminuted by different comminution devices. In general, depending on the energy events, the chromite ores having different mineralogical characteristics showed a general trend of PSDs, and hence, the ranges of D_F for a specific device. It can be concluded that breakage mechanisms have more effective on fractal dimensions of chromite samples although the mineralogical properties and size of the chromite ores broken are also a factor.     

An energy benchmarking model for mineral comminution

A method for determining the minimum practical energy for comminution was developed and is presented in this paper. An objective of the method was to determine experimentally the energy-breakage relationship for a wide size range in order to evaluate the energy performance of both crushing and grinding processes using one energy benchmarking value.Single-particle compression breakage, referred to in the field of comminution as one of the more efficient forms of mechanical comminution, was the basis for a test regimen to characterize the energy-breakage properties of ores. Existing models for impact breakage were found to be valid for single-particle compression breakage when used in a modified form. A key parameter of the adopted model, the threshold energy, was also investigated for three ore types and a range of particle sizes.The energy performance of comminution processes at a Canadian mining operation was determined by comparing the determined minimum practical energy, using the new method, with actual site specific energy requirements. In order to evaluate the energy performance of different crushing and grinding technologies, the proposed energy benchmarking method was used to compare the energy performance of alternative comminution flowsheets.     

Large particle effects in chemical/biochemical heap leach processes - A review

The application of heap leach technology to recovery of economically important metals, notably copper, gold, silver, and uranium, is wide-spread in the mining industry. Unique to heap leaching is the relatively coarse particle size, typically 12-25 mm top size for crushed and agglomerated ores and larger for run-of-mine dump leaching operations. Leaching from such large particles is commonly assumed to follow shrinking core type behaviour, although little evidence for the validity of this assumption exists. This review investigates the current state of knowledge with respect to the understanding of the characteristics and mineralogy of large particles and how these influence leaching in a heap context and the tools to characterize these. This includes the study of ore and particle properties, visualization techniques for ore characterization, the connection between comminution and leaching behaviour, as well as particle models within heap leach modelling. We contend that the economics of heap leaching are strongly governed by the trade-off between the slow rate and limited extent of leaching from large particles and the cost of crushing finer. A sound understanding of the underlying large particle effects will therefore greatly inform future technology choices in the area of heap leaching.     

邦德球磨功指数试验的影响因素

邦德球磨功指数是选矿厂碎磨流程设计和磨矿回路作业效率评价的重要依据。不同的商业化邦德球磨功指数试验流程中存在的钢球配比与磨机筒体结构的差异常常被忽略,这种差异会对邦德球磨功指数的测试结果造成明显的影响。入料粒度、产品粒度、矿石性质等因素均会对邦德球磨功指数的测试结果造成影响,在试验时需要充分考虑这些因素的影响。尽管如此,邦德球磨功指数仍然是一种方便和准确的测定矿石可磨性的标准方法。     

Discrete element method simulation of bed comminution

This paper evaluates fragmentation behaviour, particle size distribution and liberation degree during bed comminution of particles. Three different cases of bed comminution are modelled through discrete element simulations. The role of stressing velocities on breakage, effects of crushing walls on fragmentation and influence of crushing gaps on liberation and particle size distribution are considered. The discrete element sample is modelled to represent the concrete specimens of B35 strength category.It has been observed that the particles around the stressing walls fail differently than the inner particles during bed comminution. The stressing velocity and the crushing walls have been found to affect the cracking mechanism of the particles. The liberation degree in bed comminution is less as compared to single particle crushing. The results presented in this paper can be used to model the liberation and recycling of valuable aggregates from cheaper matrixes.