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By Andre Balt, Pierre Hofmeyr

It is only recently that automation has been applied to mining analytical laboratories. This paper describes the use of automation in the laboratory analytical process of hard-rock mining and geological samples and slurries in mining concentrator plant process control laboratories. Types of analysis include fire assay, XRF, ICP and wet chemistry. The benefits of automation are reduced unit cost of analyses, greatly reduced staff requirements, higher quality of data and very fast turn-around times.

Jan 1, 2005

By M. Mead, J. Dumouchel, W. Yule, J. Giroux

The QMM mineral sands of South East Madagascar contain approximately 1,900 million tonnes of mineable sand with a total heavy mineral (THM) content of roughly 4.5wt%. The QMM deposits are the world’s largest known reserves of 60% TiO2 ilmenite and also contain a small volume of zircon. The deposits are semi-continuous and homogenous and the mineralized sands are free flowing with minimal overburden, induration & slimes. These characteristics are favourable to dredge mining and allow the application of conventional wet gravity, electrostatic & magnetic separation to final products. A mature THM mineral suite of high valuable heavy minerals (VHM) content has enabled the development of a relatively simple separation process.

Jan 1, 2005

By Rudolph P. Frizzi

Structures supported on ACIP and DD piles perform successfully when quality control is maintained from the initial site subsurface investigation through pile design, bidding, and construction. The four stages of ACIP / DD pile construction are: preparation, augering the pile, grout / concrete placement, and reinforcement installation. During all four stages, careful observations and communication between the contractor and the owner's engineering inspection personnel are vital to successful pile completion. Automated monitoring equipment (AME) exists to supplement, but not replace, the field personnel's observations during the pile augering and grouting operations. Full-scale field load testing is done to verify the pile's geotechnical and structural design, and the contractor's pile installation means and methods, using several procedures including: conventional top loading, high-strain dynamic, rapid axial compression (i.e. Fundex PLT and Statnamic), and Osterberg Cell. Non-destructive sonic testing is performed to investigate the below-grade sectional properties of the completed pile; such methods include: low-strain impulse testing, and single-hole and cross-hole sonic logging. Post-construction observations are necessary to verify pile location and top properties prior to overlying cap construction.

Jan 1, 2005

By A. K. Dikshit, H. R. Murty, S. K. Gupta

This paper deals with the development of environment performance indicators (EPIs) for the steel industry. Environmental performance has become one of the key measures of business success. Emergence of continuing pressure from customers, employees, government and NGOs for environmental performance evaluation (EPE) of industries has led to evolve a framework for the development of sector specific environmental performance indicators. EPIs can be used by steel industry for assessing the continual improvement in environmental perfromance, selecting various eco-friendly options, benchmarking, environmental reporting, technology assessment and dissemination, evaluating environmental impacts and building EPIs based environmental management systems. The objective of this paper is to develop EPIs for steel industry and provide framework for development of environmental performance indicators based environmental management system and its integration with the overall management system. An indepth discussion has been presented concerning identification of EPIs, eavaluation of significance of EPIs, their prioritization and its integration with Environmental Management Systems. A new methodology has been proposed for implementing EPIs based environmental management systems . The material presented is derived in part from PhD studies of Rajesh Kumar Singh.

Jan 1, 2005

By R. L. Virta

Common clay is a natural, fine-grained material composed of hydrous aluminum silicates. Shale is a laminated sedimentary rock that is formed by the consolidation of clay, mud or silt. Production About 160 companies produced common clay and shale in 41 states. In states not reporting production, common clay and shale probably was mined and sold for construction applications by companies not participating in the U.S. Geological Survey’s canvass of producers.

Jan 1, 2005

By Paul Laframboise, Nigel MacDonald, Mike Hallewell, Robert Thorpe

"Galmoy Mine, owned by Arcon Mines Limited, has operated since 1997, and is one of three operating lead/zinc mines in Ireland. Changes in ore type starting in mid 2002 created challenges to metallurgical operations at Galmoy. This resulted in unacceptable lead and zinc flotation performance, which prompted initiation of a formal plant review and a subsequent stabilization programme. This involved a structured review of operational practices, development of a new Standard Operating Procedure (SOP) which in turn led to significant changes in process control equipment needs in conjunction with extension of zinc flotation cell residence time.This paper will describe the metallurgy of the Galmoy operation. Reasons for the poor metallurgy experienced in 2002 will be described, as well as the solutions identified to overcome these problems. By the second quarter of 2003, these solutions had been implemented and recoveries had risen to record levels.INTRODUCTIONGeneralGalmoy Concentrator is located in County Kilkenny (Refer to Figure 1 below) and was constructed during 1996 and commissioned in 1997.The concentrator at Galmoy had been designed initially to treat 650,000 tonnes per annum of primarily CW ore type. The main mineral of economic significance was sphalerite (Typically 10 to 11% Zn) with some minor galena (0.7%Pb) in a dolomite (Magnesium Carbonate) host rock.The only other competing sulphide mineral was pyrite (Circa 3 to 5% Fe in Mill Feed. This CW ore type predominated the first 6 years of production, but in August 2002, the ore mineralogy changed due to significantly higher levels of pyrite rich G ore body being blended in with CW ore."

Jan 1, 2005

By K. Poorhaydari, B. M. Patchett, D. G. Ivey

In this paper, some applications of carbon extraction replicas, as samples for transmission electron microscopy (TEM), are discussed. Modern high strength microalloyed (HSMA) steels, used as structural or pipeline materials, have very small grains with substructures. Replicas used in TEM can resolve the grain boundaries and can be used for grain size measurements in cases where the small size of the grains pushes the resolution of conventional optical microscopes. The grain size variations obtained from replicas correlated very well with mechanical property variations, indicated by hardness, in the fine-grained heat-affected zone and base metal of some welded HSMA steels. Replicas are also very suitable samples for precipitate examination with analytical TEM. Advantages and limitations of the application of replicas, as well as some corrections for the estimation of the volume fraction of fine precipitates, are discussed.

Jan 1, 2005

By K. Adham, C. Lee

The demand for nickel is continuing to exceed inventories, and producers are working vigorously to increase capacity. Many nickel processes utilize the fluidized bed technology for its fast heat and mass transfer, excellent temperature control and low maintenance. The following four nickel applications of the fluidized bed technology have been commercialized: I) Sulfide ore roasting; II) Nickel sulfide (matte) roasting; III) Nickel oxide reduction; IV) Nickel chloride pyrohydrolysis. This paper examines the issues surrounding the application of fluidization technology to the above processes, from the stand point of the engineer modeling the process and designing the key equipment, based on the historical success stories and the fundamental principles of flow sheet synthesis. Using the available data in open literature, typical flow diagrams (with convenient bases of 1 t/h feed or product) are developed to illustrate the relative flow rates and to highlight the key features of each application. In addition, some historical background information is provided for each process with supplemental notes with regards to our company's involvements.

Jan 1, 2005

By Charles Dowding, Cathrine Aimone-Martin

This article summarizes an investigation of the structural response of a brick façade home in New Mexico. The subject Ricter residence was located some 1100 to 1400 ft away from an aggregate quarry, and was subjected to a maximum peak particle velocity and air blast over pressure of 0.29 ips and 122 dB, respectively. Superstructure (corner) and mid-wall responses to blasting and human induced activities were measured. An existing exterior crack in the brick work was instrumented to measure crack width response to blasting, human induced activities, and environmentally induced changes in temperature and humidity. Crack and structure response data were correlated with ground velocity and airblast excitations. Amplification of ground motions at the upper structure were calculated and compared with values for typical wood frame structures. The natural frequency and damping characteristics of the structure were determined to compare with measured amplification values. Wall strains produced by bending and inplane tension strains were computed from upper corner structure response and compared to failure strains for drywall and brick veneer. Calculated strains were found to be far lower than those required to crack brick and environmentally induced crack response was found to be far greater than that caused by blast induced ground motion or airblast overpressures

Jan 1, 2005

By G. P. Gu, B. Fang, R. W. Revie, M. Elboujdaini

Stress-corrosion cracking (SCC) tests were conducted in the near-neutral pH standard solution, NS4, and in an actual soil solution, using four-point bending at high a stress ratio and low frequency conditions very similar to those of operational pipelines. Pitting incubation appeared first and then pitting initiated and grew in both solutions although there were many more pits on the specimen tested in soil purged with 5% CO2 + 95% N2 than in the specimen tested in NS4 solution purged with the same gas. These observations show that samples in soil solution are more susceptible to pitting than those in NS4 solution. When the pit reached a critical size, the increased stress concentration around the pits, resulted in the transition to a crack.

Jan 1, 2005

By M. Dupuis

It has been previously demonstrated [1,2] that using selective collector bar rodding has a big impact on the uniformity of the current density at the top surface of the cathode block and hence on the intensity of the horizontal current in the metal pad, The present study investigates the impact of using selective collector bar rodding on the MHD stability of a 500 kA aluminium electrolysis cell, For this purpose the recently developed MHD package for the aluminium reduction cell time dependent behavior is used.

Jan 1, 2005

By R Lloyd

Coal Services (Health and Safety Trust) funded ARRB Transport Research Ltd to investigate fatigue and performance of truck drivers over consecutive shifts. The main questions were to assess: What is the most important contributor to acute fatigue in mining? Is it length of shift (eg eight hours versus 12 hours) or is it time of day (eg circadian effects)? What is the limit of successive day or night shifts before chronic fatigue affects operator performance in open cut mines? The project methodology included utilising ARRB Fatigue Monitoring Devices (forced-choice stimulus reaction) in eight haul trucks, testing 24 subjects over several weeks. Each subject filled in a Fatigue Risk Questionnaire on lifestyle and health. Operators worked a 14-night, one day off, 13-day roster of 12-hour shifts in a fly-in/fly-out operation with excellent opportunities for restorative sleep between shifts. A total of 3500 hours of real-time data was collected, representing the first set of objective, real-time driver performance data for Australian mining. The data showed that for a single night of driving haul trucks, there appears to be no effect on operator fatigue from the amount of time on task (for the 12 hours). In fact performance was worse through the first eight hours than the last four. The circadian influence had a stronger affect than working more than eight hours. Of the 14 nights worked at the site, nights 13, 14, seven and two respectively, were the worst. This presents a conundrum for policy makers who may like to place caps on working hours or rosters in the hope that it will alleviate the fatigue issue. It will not. The major finding within this study is the combined influence of circadian rhythms (human body clock) and individual variability on performance. The lifestyle habits and the health of individuals have a profound effect on operator performance as shown by the strong positive correlation between high fatigue risk scores from the Fatigue Risk Questionnaire and poor performance. An individualistic approach would appear to have the best chance of reducing high potential incidents due to fatigue through successive nightshifts.

Jan 1, 2005

ICMM’s vision is ‘a viable mining, minerals and metals industry that is widely recognised as essential for modern living and a key contributor to sustainable development’. The ICMM Sustainable Development Framework provides the basis for achieving this vision by assisting the industry to improve its performance. Two years on from the first SDIMI conference, significant progress has been made in further developing and implementing the Framework. To fulfill their commitment to implement and report performance against the ten sustainable development principles in the Framework, ICMM’s corporate members have committed to report ‘in accordance’ with the GRI 2002 Sustainability Reporting Guidelines and the Mining and Metals Sector Supplement, developed by the GRI and ICMM. While much remains to be done, development of the Supplement and the commitment to reporting mark an important milestone for ICMM and the sector.

Jan 1, 2005

By H. Abdollahi

Cold rolling is one of the most important techniques in metal forming since the cold rolling products are almost finished product, The product quality of this process is widely influenced by friction in the roll gap; therefore, controlling the friction and other parameters affecting the cold rolling is very important in order to have a product with high quality, Among the cold rolling parameters, the pressure distribution or friction hill within the roll gap is known as the most significant one, In this study, a new software (Matroll), is introduced which can determine the coefficient of friction (COF) and plot the friction hills for an industrial mill, Besides, based on rolling equations, it offers about 25 rolling parameters as outputs. To verify the software operation, the real industrial rolling data was used as inputs, The results (outputs) are in good agreements with the findings of other researchers, The COF values are very reasonable, The friction hill shows that COF is not constant over the whole arc of contact.

Jan 1, 2005

By B Mohanty, G Yamin

A number of parameters, aside from blast design and pre-existing rock conditions, can change the performance of the explosives system in actual blasting practice. Sympathetic pressures caused by detonation of preceding holes have been identified as a major contributor to explosive system malfunctions, leading to uneven blasting performance. These effects can occur both within a hole or across several holes. These can consist of high transient pressures related to the shock phase of the explosion or the relatively longer or quasi-static pressures associated with the explosion gas expansion phase. This study presents the findings from an on- going investigation on measurement and analysis of these pressures between donor and receptor holes in a granitic outcrop for representative inter-hole distances and borehole conditions, employing single cartridges of emulsion explosive in 45 mm diameter holes. The results, despite wide scatter in the measured values, show the very short duration pressures to range up to 7 MPa and arriving within a few milliseconds after detonation, whereas the much lower amplitude pressures arrive after tens of milliseconds. Both have the potential to seriously affect the performance of an explosives system.

Jan 1, 2005

By Randy Sandrik

Sampling has evolved at two large underground limestone mines as conditions and product requirements have grown tougher over 100 years of mine life, requiring innovative techniques to insure delivery of high purity limestone. Sampling insures delivery of consistent product to customers at the lowest possible cost. Statistical considerations have evolved from simple data collection to predictive and process capability analysis. Sample methods include borehole samples, face (using a proprietary face-sampling device), and total plant feed automatic, process, and final product sampling. Lessons learned, while keeping costs at historically low numbers, include the importance of geological models, exploration drilling density, face sampling, and blending of ore.

Jan 1, 2005

Breaks in coal slurry impoundments can threaten the lives and health of area residents, destroy homes and businesses and contaminate water supplies. This dangerous potential looms over coalmining regions in West Virginia and throughout Appalachia. The Coal Impoundment Project was begun in June 2003 to provide an inventory and mapping of active and abandoned impoundments in West Virginia. The project also provides the public with specific information about the impoundments in their communities. It is dedicated to alerting residents of danger and evacuation plans, reducing risk to residents and finding alternatives to impoundments. Since its first year, more than 100 impoundment sites have been added to the project’s Website.

Jan 1, 2005

By F. Khomamizadeh

In this study, deep cryogenic treatment was applied to A319 cast aluminum samples. Although the cryogenic treatment didn't have any significant effect on mechanical properties of the well degassed and fluxed samples, but the tensile strength of the samples containing a considerable amount of gas and shrinkage defects was improved surprisingly, This improvement was attributed to the strengthening of the a-aluminum matrix which slows down the propagation of the existing defects. There was no significant increase in the hardness after cryogenic treatment, The abrasion resistance of the alloy was improved after cryogenic treatment, by developing a homogeneous protector shield, composed of abrasive grains penetrated into the soft aluminum matrix and kept tight.

Jan 1, 2005

By P. C. Sui

Numerical investigation and parametric simulations of the coupled electrical conduction and mass diffusion in the GDL of a PEMFC are reported. The coupled transport is solved using a 2D, "under-the-rib" computational domain for the cathode GDL. The current density on the GDL/catalyst layer interface, which constitutes one of the boundary conditions for the GDL domain and reflects the activation overpotential in the catalyst layer and the ohmic loss in the membrane, is solved iteratively using a novel numerical algorithm. A parametric study is performed to investigate the effects on current density distribution of various operating conditions such as oxygen concentration and membrane resistance, and of design factors such as GDL geometry, anisotropic transport properties, and deformation under the land area. The results show that the current density distribution under the land area can be dominated by either electron transport or mass transport, depending on the operating regime.

Jan 1, 2005

By P. Harvey

"Following initial discovery in 1991, BHP Billiton Diamonds Inc. opened Canada’s first diamond mine, the EKATI Diamond Mine (EKATI) in the Northwest Territories on October 14, 1998. Four short years later, on November 29, 2002, saw the opening of North America’s first underground diamond mine, the Koala North mine. Nestled between the original Panda open pit and the new Koala pit, which is in the early stages of production, Koala North represents the only underground kimberlite mining venture in Arctic conditions outside the new underground mines being developed by ALROSA in the Yakutsk region of eastern Russia. Extensive underground kimberlite mining has been practiced in the Republic of South Africa for much of the 20th century and continues today.Underground mining represents a key component of the long-term business plan for EKATI. As various open pits reach their economic limit, continued recovery of high-value ore at depth is dependent upon the ability to productively mine the kimberlite pipes by underground methods. As a function of its location, size, and value, the Koala North pipe is ideally positioned to host the first underground mine at EKATI. Koala North is designed and approved as a learning mine, from which to gain valuable experience in preparation for the potential mining of other larger, higher value pipes by underground methods in the development, the Koala North mine is well into its production ramp-up phase and currently producing at around 1,200 t/day from the first two production levels."

Jan 1, 2005