基于80C552单片机的平仓机载荷限制器的研制

分析港口作业中平仓机操作安全的重要性,介绍了新研制的平仓机载荷限制器。该测控系统采用高性能单片机80C552及超大规模集成电路PSD311,简化了电路设计,提高了载荷限制器可靠性。     

Mine system availability concepts

ABSTRACT

During the last few years, there has been a marked tendency in mining industry to adopt complex and sophisticated technology to make mining operations economically viable. The concepts of integrated operating systems are being gradually introduced with increasing pace of automation in mines. This paper discusses the concepts and various forms of system availabilities which can be used by mine engineers and managers for controlling the system performance. Examples are given to show the differences between these availabilities. The concept of availability target setting is also introduced in brief.     

The Influence of Engineering Scale and Environmental Conditions on the Performance of Compost Bioreactors for the Remediation of Zinc in Mine Water Discharges

The effects of engineering scale on the performance of a compost-based system for the remediation of a discharge from an abandoned metal mine was investigated by simultaneous operation, under field conditions, of a laboratory-scale column and a pilot-scale system. The two systems contained identical reactive substrate, comprising limestone gravel, compost, wood chips and activated sludge from a municipal waste water treatment plant, and had an initial hydraulic residence time of approximately 19?h. The influent mine water contained around 2?C2.5?mg/L zinc and had a circumneutral pH. Clear differences in the performance of the systems were seen, demonstrating the importance of engineering scale in the remediation of zinc. The laboratory-scale column was most effective at removing zinc, with approximately 96?% of the influent zinc attenuated within the system, while the pilot scale system removed, on average, 84?% of the influent zinc. The poorer performance of the pilot-scale reactor may, in part, be due to preferential flow, as indicated by a greater reduction in hydraulic residence time than in the laboratory-scale system. Early indications are that temperature also plays an important role in the attenuation of zinc within such systems, possibly linked to reduced microbial activity during periods of low temperature. Despite an apparent decrease in sulphate concentration within both systems, it is unclear whether bacterial sulphate reduction is the dominant mechanism for metal removal or whether sorption processes prevail. Implications for full-scale design of these treatment systems are discussed.     

Numerical solution for dynamics of pneumatic DTH hammer system

The pneumatic down-the-hole(DTH)hammer is one of the efficient equipments used in medium hard to very hard rock drilling frield,and any change in its structure design affects all performance parameters of a pneuamtic DTH hammer directly.Yet,owing to the complexity of the dynamic interaction among the components in DTH hammer systems,until now it has been difficult to obtain reliable estimates of the design parameter affects.Thus providing an design parameter optimization and the layout of dynamics behavior of DTH hammer is of great importance.This paper documents the development and solution of a computational model for the dynamic response of a pneumatic DTH hammer.The model consists of rigid piston dynamics equation and chamber thermodynamics equations.The resulting model represented by a set of coupled nonlinear differential equations were computed in Visual C++ program.The developed solutions are used to perform a parametric study to illustrate the inffluence of the piston mass and supply pressure on the impact performance of DTH hammer system.     

摩擦衬垫摩擦系数测试实验机的设计与实验分析

以摩擦式提升机的钢丝绳与衬垫间的摩擦学性能检测和矿井提安全的重要问题为工程背景,研制出了钢丝绳摩擦衬垫磨损检测系统,并对其进行了性能分析和实验研究,对矿井安全生产有着理论和现实意义。     

Modelling of discrete downtime in continuous crushing operation

Crushing is a harsh process and production units are subjected to wear and failure over time which will reduce the overall performance of the plant. To achieve optimum process performance, both time dependant process dynamics and operating conditions should be taken into account.In this paper the aim is to simulate the process from a more operational perspective to evaluate process performance and process optimum for different operations. The objective is to model and simulate the discrete phenomena that can cause the process to alter performance and implement it with dynamic process simulations. An approach for combining discrete event simulations with time-dependent simulations for process evaluation and optimization is presented.The proposed approach demonstrates a systematic way to evaluate the process performance and locating optimum process configuration, for a given condition. The developed models can be used to optimize different aspects of the operation depending on the defined objective function and the system boundaries. Optimization of process throughput by manipulating configuration of both the grizzly and the crushers, as well as the time between calibrations has been illustrated in this paper. Adjusting the process continuously and calibrating it at the appropriate time can have major benefits when it comes to the process availability and utilization, increasing performance by 4.1–9.3% in these cases. Evaluation of process robustness and availability with regards to process specific factors and variation gave an indication of the process and unit performance under a long operating period. By combining discrete and dynamic simulation, a higher simulation fidelity can be achieved to provide a more operational perspective to the optimization and process analysis.     

Artificial Neural Network Prediction of the Performance of Upflow and Downflow Fluidized Bed Reactors Treating Acidic Mine Drainage Water

The performance of fluidized bed reactors treating synthetic acid mine drainage were predicted using an artificial neural network (ANN). The developed model gave satisfactory fits to the experimentally obtained sulfate, COD, alkalinity, and sulfide data; R-values were within 0.92 and 0.98. ANN can be effectively used to predict the performance of these complex systems and, with the proposed model-based applications, it is possible to reduce operational costs and risks.     

Statistical monitoring of a grinding circuit: An industrial case study

With the increasing availability of large amounts of real-time process data and a better fundamental understanding of the operation of mineral processing units, statistical monitoring of mineral processing plants is becoming increasingly widespread. Process plants are typically too complex to model from first principles and therefore models based on historical process data are used instead. Multivariate methods such as principal component analysis are indispensable in these analyses and in this paper, it is shown how the statistical analysis of process data from a grinding circuit and a sound fundamental knowledge of the operation of mineral processing plants complement one another. For this purpose a philosophy for the statistical monitoring and cause and effect analysis of a process was outlined. It was shown how a well defined process hierarchy with complementing performance measures can effectively be used to detect a shift in the operation of a mineral processing plant and find the root cause of the shift. Visualisation of the results was found fundamental in communicating the findings of the statistical analysis to the processing plant. This resulted in the requirement for multidimensional visualisation of the process for which principal component analysis plots and process performance graphs in the form of two-dimensional histogram plots and parallel plots were found to be the most effective. Data availability, process variable selection, process hierarchy definition and performance measure selection were also found to be critical factors directly impacting on the success of statistically monitoring a process.     

论计算机软件测试的重要性

自人类用语言编程把程序写出来的那一刻,就标志着"软件测试"已经诞生了,由于人们对计算机应用程序依赖的加深,计算机软件也越来越复杂,计算机软件测试的重要性也被人们所重视起来。如今科技发达在软件开发的过程中为了整理软件的性能及满足用户使用的需求,软件测试成为了软件开发中的重要步骤,也是软件质量保证的手段之一。     

基于multi-agent的煤矿水害演化模型

根据矿区的水文地质条件,分析了煤矿水害事故的形成原因和演化机制,采用复杂系统理论和多主体建模方法,建立了煤矿水害演化模型;利用NetLogo仿真平台,对不同类型水害事故进行仿真模拟,动态表现煤矿水害演化过程以及影响因素之间的脆弱性关系。研究表明：煤矿水害是一种受控于多种因素、具有非线性动力特征的复杂自适应现象,只有了解矿区水文地质条件,并将复杂系统理论和多主体建模方法引入水害防治研究中,才能从本质上描述水害演化机制。     

Study and application on fire extinguishing and preventing with light-paste material for coalmine

For preventing and extinguishing the spontaneous combustion of coal seam, based on the importance for sealing air leakage channels in roadway, developed a material of light-paste for coalmine, and research its ingredient, proportion and performance. The result indicates that the component ratio of the material is which PB exciting agent is 20%, complex reinforcing agent is 2%, complex expansion agent is 1%, and A-material is 77%. The performances of compressive strength, swelling ratio and expansion time are optimum. The light-paste material can effectively seal air leakage channels for preventing and extinguishing the spontaneous combustion of coal seam in coalmine.     

Monitoring of mineral processing systems by using textural image analysis

In the last few decades, developments in machine vision technology have led to innovative approaches to the control and monitoring of mineral processing systems. Image representation plays an important role in the performance of the recognition systems used in these approaches, where the use of feature representations based on second-order statistics of the image pixels have predominated. However, these representations may not adequately capture or express the visual textural structure associated with the observed patterns in images. In this study, the use of texton and complex multiscale wavelet representations (steerable pyramids) that exploit higher-order statistical regularities, is investigated. These techniques are applied to two image data sets: industrial platinum group metals froth flotation, and coal particles on a conveyor belt. Compared to grey level co-occurrence matrix and classical wavelet representations, these are observed to improve performance when used as input in the pattern recognition phase.     

基于模糊神经网络振动磨机控制系统研究

针对振动磨机破磨过程的复杂非线性,设计了二维模糊控制器;模糊控制过于依赖领域专家的先验知识,缺乏在线学习功能。将模糊逻辑推理与神经网络的自学习功能结合起来,提高整个系统自学习能力及表达能力,进一步改善了控制系统的动态性能,提高自适应能力。仿真实验证明了所提出BP算法的有效性。     

煤矿地测综合管理信息系统探析

随着计算机技术的不断发展,计算机软件的开发和应用已经深入到人们的生产生活中。而计算机信息系统应用于煤矿地测综合管理极大提高了煤矿地测的水平。文章介绍了煤矿地测信息系统的方法和管理目标,为信息系统更好地发展提供了基础。提高煤矿地测综合管理的精度和质量,关键在于提高地测工作的计算机信息系统。     

Selection procedure for hydraulic impact system parameters

The developed procedure to select parameters of positive-displacement hydropercussion systems has two stages. The first stage is the picking of the key parameters; the second stage is the engineering design of the system, adjustment of the selected parameters using the multivariate optimization procedure and the improvement of the system performance.     

云南小型矿山通风系统建立的若干问题分析

矿井通风系统作为金属非金属矿山地下开采八大系统之一,其建立并可靠运行对矿山地下开采有重要作用.云南省作为全国矿业大省,矿产资源分布广,拥有大量的矿山企业.其中,小型矿山开采过程中,未充分意识到矿井通风系统建立的重要性.本文针对目前这些矿山通风系统建立中存在的一些主要问题,提出云南省小型矿山通风系统建立的途径,以便为小型...     

下运带式输送机复合制动系统仿真及试验研究

针对现有各制动技术在单独作用时出现的一些缺限,致使其无法解决下运带式输送机由于输送物料愈发具有随机性、非线性和时变性等特点而带来的制动难题,提出由液压软制动器和液压瞬时盘式制动器组成的下运带式输送机恒减速复合安全制动系统,使其可以满足现有下运带式输送机制动要求,并且能在载荷实时变化下都能实现恒减速安全制动;在阐述两种制动器各自工作原理及实际使用过程中存在的缺点后,建立和分析了两制动器工作时的数学模型,并由此建立复合制动系统工作时的数学模型和仿真模型,对复合制动系统制动性能进行了仿真分析,完成了复合制动系统制动性能的试验研究。研究结果表明：复合制动系统能充分发挥和结合两种制动器的制动优点和特性,弥补了两种制动器单独使用过程中存在的缺点,实现了下运带式输送机在载荷实时变化下的恒减速度安全制动,避免了下运带式输送机安全事故的发生。     

Development of a flotation model incorporating liberation characteristics

A liberation/flotation model has been developed to evaluate flotation performance, in which the grade distribution of composite particles is incorporated explicitly. The grade distribution of particles at a given size fraction was calculated using a predictive liberation model developed by the authors. Flotation behaviour of these particles in narrow size fractions were evaluated using batch flotation tests. The recovery of particles in narrow size/grade classes at various flotation times under a given flotation environment were obtained from SEM images of mounted specimens of feed, concentrate and tailings samples using image analysis techniques.By describing the size, grade and recovery data of particles in narrow size/grade classes by separate matrices, a transformation matrix technique has been developed that can predict the flotation performance of a composite sample of an ore comprising various size classes. It has been shown that the predicted results agree well with the observed results.This liberation/flotation model has wide applications in geometallurgical testing and design, where the downstream flotation performance is to be determined with limited availability of ore samples and their liberation characteristics. It also alleviates the deficiencies involved with flotation models that assumes first order behaviour.     

煤矿通信系统中的建模仿真研究

随着通信技术的高速发展,通信系统的功能越来越强、性能越来越高、结构越来越复杂。另一方面,通信系统技术研究和产品开发的周期越来越短。这是因为强大的计算机辅助分析设计技术和仿真技术的应用。通过对通信系统的深入研究,本文对煤矿中通信系统的建模仿真研究有了阶段性成果,对于研究煤矿通信系统的研究人员,具有一定的参考价值。