Numerical investigation of a heuristic methodology for designing precise metal accounting measurement networks

This paper presents a numerical investigation of factors that influence the design of precise measurement networks based on the random error reduction attributes of data reconciliation. The cited factors provide a basis for developing design heuristics that target specified streams for maximal variance reduction. In this investigation, distinct network structures were generated from a case study flowsheet using a strategy that conserves the input and output stream configuration across all generated candidates. The factors were assessed by determining the extent of variance reduction experienced after data reconciliation. Input and output flows were targeted for optimisation owing to their custodial importance in high precision measurement applications such as metal accounting. The results confirm the dependence of variance reduction on measured variance as concluded in previous studies. However, the ratio of stream to parent-node variance emerges as a better predictor of variance reduction for individual streams, particularly in complex network structures.     

金属矿山主井进风流空气净化新装置研制

结合某矿山主井进风流含尘空气净化实例,设计开发了以波形板为主材的净化除尘装置。本装置汇集了湿式粘附、凝并、碰撞、惯性、重力等复合除尘原理,具有阻力小、过风量大、粉尘净化效率较高、管理维护方便、运行成本低的特点。该装置采用模块化设计思路,针对矿山环境具有较强的灵活性和适应性,具有广泛的推广应用价值。     

井底参数新型检测手段设计研究

绝缘硅（SOI）是一种新型电子材料。俄罗斯利用SOI技术设计研究出了一种新型井底参数检测手段,包括顶角测量仪和井底钻井液压力测量仪。这种手段具有热稳定性好、抗辐射能力强、精度高、灵敏度好和可靠性高的特点。建议引起重视并对此进行讨论和研究。     

Development of a techno-economic simulation tool for an improved mineral processing plant design

Simulation is widely used in design and optimization of mineral processing circuits to answer “what if” questions regarding the employment of different equipment and configurations. The questions could be answered better if the long-term economic impacts of different circuits are readily estimated within the designing stage, considering both economic and technical constraints and criteria. This paper introduces a new open source user-friendly techno-economic simulator developed in Matlab/Simulink that joins multivariate capital and operating cost models to technical models of equipment and estimates some economic analytical indicators of the circuits such as Net Present Value simultaneously when the circuit is being designed. The proposed approach enables the designer to easily consider the technical and economic interactions and tradeoffs. As a case study, the long-term economic impact of selecting different numbers of leaching tanks is investigated and it is shown that even the optimum number of tanks could be a function of discount rate of the project.     

The use of ion exchange resins for the treatment of cyanidation tailings part 1––process development of selective base metal elution

This work investigates the use of oxidative acid eluents for the elution of base metals from strong base ion exchange resins. Eluents composed of a mixture of H₂O₂ and H₂SO₄ were tested for eluting base metals from resins loaded with mixtures of base and precious metal cyanides. This process removed 100% of Cu and Zn loaded on the resin, without affecting the precious metal loading. It was found that copper could be removed separately from the other base metals. The elution technique was not effective for removing iron from the resin. Cyanide associated with base metals was recovered as NaCN. Some oxidation of cyanide was noticed, subject to the elution conditions.This oxidative acid elution process could be used in commercial operations for the selective elution of base metals from a strong base ion exchange resin bed operating in alternative adsorption/base metal elution cycles. Thus, virtually all metal cyanide species could be recovered from cyanide leached solutions or slurries to give relatively clean tailings without compromising precious metal recovery efficiency. The process also caters for cyanide recovery and recycling.     

Seismic vibration treatment of a pay zone for improvement of the filtration and production parameters of underground metal leaching

The paper sets forth the results of the theoretical and experimental research of the low frequency vibroseismic treatment effect on the permeability and metal recovery of an aqueous uranium bearing rock formation. The main vibro-treatment parameters, such that to improve the filtration and production characteristics of the underground metal leaching via wells, are determined.     

Development of a new covering strategy in Indonesian coal mines to control acid mine drainage generation: a laboratory-scale result

The waste dump of sulphide-containing rocks is one of the potential acid mine drainage sources, since it contains a huge amount of readily oxidised sulphide mineral, due to its exposure to air and water. The application of the dry cover system is regarded as one of the best practices since it prevents acid mine drainage of the waste rock dump at the surface coal mine. However, the implementation of the dry cover system in field practice has faced several obstacles due to the limited number of cover materials. The nature of geological condition is considered to be a controlled issue, whilst the problem is the mining method and equipment size. This article describes the acid generation mechanism and its control, application of cover system and the problems that are faced in Indonesian coal mines, whilst discussing the preliminary laboratory results of multi-layer cover systems. It finally proposes a new covering strategy in an attempt to overcome the problem.     

Development of a method for separation of PVC and PET using flame treatment and flotation

Flame treatment can be used to modify the surface of plastics to allow water-based coatings to be attached. The effect of the treatment is to produce hydrophilic species on the surface of the plastic. The process is therefore potentially useful for the separation of plastics by froth flotation, provided that the production of the hydrophilic surface can be achieved selectively. Polyvinyl chloride (PVC) and polyethylene terephthalate (PET) were selected for investigation as they are found as a co-mingled product from the recovery of beverage containers.In this paper we report on the development of a simple, but effective, flame treatment method for flaked plastics. The treatment involves the use of an acceleration chute that delivers the flakes through the flame of an angled burner. In experiments with virgin plastics the PVC was found to be less susceptible to surface modification than PET, as indicated by contact angle measurement. Separation of the treated virgin plastic by froth flotation was found to be possible, using careful control of frother addition.The technique was then considered for the treatment of post-consumer plastic bottles. It was demonstrated that flame treatment was effective in rendering the surface of both plastics hydrophilic, although the process alone was not sufficiently selective. Hydrophobic recovery of the PVC, but not the PET, was achieved by raising the temperature of the material to 140 °C for a period of 10 min. A two-stage flotation process was tested for the separation of the plastics. In the first stage the PET was floated away from the PVC utilising differences in particle thickness and surface contamination. The float product was then subjected to flame treatment and hydrophobic recovery prior to the second stage of flotation. In this stage the PVC reported to the float product leaving a PET-rich sinks fraction.     

地下开挖地表移动变形可视化系统开发

地下开挖必然会导致地表发生相应的移动与变形,而当地表的移动变形超过某一范围时,就会破坏地表的建筑物。通过预计地表的下沉、倾斜、曲率、水平移动和水平变形的大小和影响范围,就可以判别建筑物是否受到开采的影响以及受到开采影响的程度,从而科学指导地下开采。主要以概率积分法为理论基础,Matlab软件为编程平台,实现了地下开采地表移动变形的可视化,充分利用Matlab平台的优势,弥补了过去相似软件在某些方面的不足,为地表移动变形计算分析提供了帮助。     

The use of a new type of large vacuum batch furnace for the heat treatment of moulds and dies

The primary focus in vacuum heat treating of dies for the die casting industry is to reduce distortion, while obtaining a smooth surface finish with no post cleaning needed and easy process control. A slower gas quenching reduces distortion, but special larger dies show grain boundary precipitation with the consequence of a shorter die life. — With the increased use of high-pressure gas quenching and faster quench rates for moulds and dies, the quality of heat treatment has improved significantly over the last ten years. With quicker quench rates, distortion and post machining increased which, however, was accepted in return for the improvement in lifetime despite an increased risk of quench cracking. This paper discusses the vacuum heat treating of moulds and dies (over 5 metric tons) in the newly developed Super Turbo^TM vacuum furnace with 15·10⁵ Pa nitrogen gas quench combined with directional cooling.     

套装式立井井架技术研究及应用

鹤壁煤电公司三矿主井井架技术改造成功地采用了套装式立井井架技术，该井架结构的施工方案尚属国内首创。实现了新、老井架联合运行，有效地缩短了停产改造时间，井架的强度、刚度、稳定性和高度都能满足《煤矿安全规程》和现行抗震规范的规定以及矿井扩大提升能力后的要求，社会效益和经济效益显著。整体技改方案适应煤炭行业能力挖潜、立井井架技改，极具推广价值。     

Development of a Management Tool to Support the Beneficial Use of Treated Coal Seam Gas Water for Irrigation in Eastern Australia

An infiltration and salinity transport model (ISTM) based on the HYDRUS modeling platform was developed to support the beneficial use of treated coal seam gas (CSG) water to irrigate perennial forage plots in eastern Australia. The ISTM was used to support the expansion of irrigated areas under the CSG industry’s first specific irrigation beneficial use approval issued by the Queensland environmental regulatory administering authorities in March 2009. To support meeting regulatory requirements for expansion beyond the original irrigation area, forward modelling within the vadose zone was used to evaluate the fate and transport of the irrigation water as it migrates through the shallow soils and unsaturated bedrock toward the saturated zone; simulations beneath three agricultural systems with contrasting infiltration capacities were assessed. The model simulation results were used to guide irrigation activities to maximize water use in the readily available soil water capacity range for these agroecosystems, without detrimental impacts to plant growth or surface water/groundwater and soil resources. In this paper, a practical irrigation and rainfall systems-driven hydrogeochemical conceptual model is presented to identify processes that are likely to govern infiltration from the land surface, root water uptake, and solute transport into, and potentially through, the unsaturated zone. A numerical model is then parameterized to represent the primary processes hypothesized to affect water and salinity movement in the vadose zone. Finally, a series of simulations, conducted to identify the key parameters and processes governing the potential movement of water and salt through the root zone and into the bedrock vadose zone, are discussed. The simulations are used to support continuous improvement in modeling approaches for sustainably managing treated CSG extraction water allocated to irrigation.     

进一步整顿规范煤炭行业秩序 开创山西经济社会转型跨越发展新局面——聚焦2011年山西省煤炭工作会议

4月20日,2011年山西省煤炭工作会议在太原召开。山西省委副书记、省长王君作重要讲话,省人大常委会副主任、省总工会主席郭海亮,省政协常务副主席郭良孝等出席会议。山西省副省长任润厚主持大会并讲话,省煤炭工业厅厅长王守祯作了题为《加快转变煤炭经济发展方式,推动煤炭工业转型跨越发展》的主题报告。