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By IPMI Educational and Scientific Foundation

It is with great pleasure that we announce the availability of this fourth issue of the IPMI Journal, a publication of the International Precious Metals Educational and Scientific Foundation. This digital peer reviewed publication has been created as a vehicle for the sharing of technical information related to the science and technology of precious metals. Since 1976, the International Precious Metals Institute has championed the exchange of information of critical importance to the precious metals scientific and commercial communities through its various communications vehicles. This has included instructional videos, annual conference symposia, special topic committee meetings, regional seminars, and professional and student achievement awards. Due to the breadth of important topics related to all aspects of precious metals, it has been the vision of the IPMI to provide a publication available to the general public that would become a key source of pertinent topics containing high quality publications by experts in their fields of study. Historically, the IPMI has attracted world renowned experts in many fields (including Nobel Laureates Henry Taube, Ei-ishi Negishi, Robert Grubs, Professor Ben Feringa, and David MacMillan) in the dissemination of discoveries, inventions, and industry proven practices. Such information has a total value greater than the sum of its parts as seemingly unrelated innovations from distinct focus areas can be adapted to solve problems. Because of this important characteristic of information exchange, we have decided to create a digital journal, available to the general public, that will not only communicate state of the art discoveries and sound practices, but will also review historical communications from the IPMI’s archives that have value and use even in today’s environment. On behalf of the members and leaders of the IPMI, we hope you will find value in this new publication.

Dec 1, 2022

By A Kitchen

For the past decade, demand for Australian resources has reached unprecedented levels, thanks mainly to the emerging superpowers of China and India. Meeting demand has meant miners and governments alike have ploughed billions into capital expenditure projects for logistics infrastructure such as roads, rail and ports, to support the ever expanding number of mines and mineral volumes. In more recent times, however, the effect of the global economic crisis has led to a decline in demand for Australian minerals. The downturn has seen companies lay off workers in droves, and delay or cancel expansion projects, in an attempt to preserve cash flow. Whilst the current economic cycle has hit the mining sector hard, it is an opportunity for companies to take stock of their existing operations and plan for the future. As mining companies grapple for scarce capital resources, it is inevitable that industry consolidation will ensue. This presents challenges and opportunities for both buyers and sellers alike, looking to expand operations, or sell off assets to raise cash.

Jan 1, 2009

The state of sampling practice in South African minerals industry must be appreciated in the context of the changes that the country has recently lived through. These include the entrepreneurship and investment in local mineral developments, the 'unbundling of mineral assets', the rising foreign control of South Africa's mineral assets, developments in the regulatory environment, and the training that has come to the industry through international experts. In terms of their financial contribution the five most important commodities in the South African mining industry include gold, platinum, non-ferrous metals, ferrous metals, and coal. International Organization for Standardization (ISO) standards form the basis for international trade in two of these commodities and have had a steadying influence on sampling practice over the years. The contribution of the minerals industry to the economic well-being of South Africa and the strong financial links between good sampling practice and minerals marketing, has acted as a driver for improved sampling practice. The state of sampling practice at mining operations of the five main commodities was found to be quite widely divergent with 'pockets of sampling excellence' in each of the commodities. The stages of mineral development at mines for each of the commodities have been described in terms of the sampling sites, sampling mechanisms, and associated problems at different stages of mineral production from exploration, through face sampling, blasthole sampling, and in-mine grade control, ore processing and handling, metallurgical subsampling, process subsampling, and subsampling in the laboratory. In each case the principal errors were identified and their potential impact on value erosion was estimated. In the final analysis it is evident that the greatest problems arise in the early stage of mineral development, and that ferrous metals and coal are particularly susceptible to loss of value through poor sampling practice. Several examples of value lost through poor sampling at the marketing stage that arise from breaching contract specifications, either in terms of grade or sizing, are described. The conclusion is that larger companies with larger ore deposits and greater human, financial, and capital resources are probably more compliant with 'best sampling practice' than smaller companies. Finally the message that equipment suppliers are sending is that business is booming and the awakened awareness of the issues around sampling practice are translating into rands and cents spent on improved sampling equipment.

Mar 1, 2010

By M. Kahn

This paper traces the rise of South Africa's mining industry in the context of the different state forms that oversaw its development. It commences with the mining-led industrial revolution through four periods of conflict, each of which contributed to a deepening of the industrial base, with constant battles between domestic and foreign capital and labour, and the rise of both Afrikaner and African nationalism. The role of state-owned enterprises has been crucial in shaping this dynamic so that at its peak the public sector and leading mining houses constituted two massive centres of power. This was followed by a thirty-year period of neo-liberal experimentation. The current debate on the 'developmental state' is an attempt to reconstruct the state as a counterweight to capital. It is argued that while the country has moved toward inclusive political and economic institutions, these are both limited by deep 'extractive' characteristics. This transformation failure provides a fertile ground for populism that presents one of the biggest threats to inclusive growth. Cited examples point to the many ways that states have sought to deal with the bonanza that conversion of mineral non-resources into resources brings. Such greenfield resources on state land, or in areas where the state holds monopoly rights, do not present ownership issues. It is suggested that this is the route that South Africa should follow, as the alternative will be conflictual.

Jan 1, 2013

By J Fraser, M Scoble

Within the past decade, incidents of mining–community conflicts have grown dramatically and represent one aspect of a phenomenon known as social risk. Research published in 2014 indicates that a lack of social acceptance is now a leading and costly cause of delays for mining projects.The rise of social risk, complemented by the need to earn the trust of an increasing number of stakeholders so that mining projects can be developed effectively, is problematic for the industry. Conflicts are occurring in situations where companies are fully compliant with regulatory and legal requirements, despite initiatives by mining companies to earn social acceptance and despite the proliferation of tools to support corporate social responsibility. Intensifying the impact of social risk is the fact that it has increased during a time in the global mining sector when companies have had to grapple with declining commodity prices, increasing capital costs and debt levels and the challenges of mining lower-grade deposits.This paper will explore a hypothesis that in today’s interconnected society, social risk in the mining sector constitutes a legitimate business risk that must be managed strategically. The reality facing mining companies is that information, once considered confidential, now travels quickly on social networks and via a growing number of groups and individuals that have earned a legitimate right to be classified as stakeholders in projects that affect their communities. To be successful, it is suggested that companies will benefit from increasing internal collaboration and providing training to equip teams to mitigate social risk to mining projects and protect reputation capital. The paper is based upon PhD research being undertaken to assess the points of intersection between social risk and social responsibility during the construction stage of greenfield mining projects.CITATION:Fraser, J and Scoble, M, 2015. Mining–community conflicts – can the future mining sector transform social responsibility?, in Proceedings Third International Future Mining Conference, pp 159–168 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Nov 4, 2015

A model was developed to facilitate secondary tailgate support selection based on analysis of over 100 case studies, compiled from two different surveys of operating longwall coal mines in the United States. The ALPS (Analysis of Longwall Pillar Stability) program was used to determine adequacy of pillar design for the successful longwall case histories. A relationship was developed between the secondary support density necessary to maintain a stable tailgate entry during mining and the CMRR (Coal Mine Roof Rating). This relationship defines the lower bound of secondary support density currently used in longwall mines. The model used only successful tailgate case history data, with adequate ALPS SF according to the CMRR for each case. This model facilitates mine design by predicting secondary support density required for a tailgate entry depending on the ALPS SF and CMRR, which can result in significant economic benefits.

Jan 1, 1996

By Andrew B. Cecala, Emily J. Haas, Jay F. Colinet

A sociotechnical system (STS) creates a framework that allows an examination of how social and technical factors affect organizational outcomes within a specific environmental context. STS has been rigorously studied with a primary research focus addressing worker-technology interactions. Although these interactions are important, the social processes and interactions that occur whenever any technical or environmental change is introduced into the system have been undervalued. If social processes are better understood, mining organizations could efficiently prepare and stabilize for such changes. With this goal in mind, we sought to extend STS theory through applying principles of meta-design to analyze the results of two case study interventions. Specifically, we studied the impact of an unregulated dust control technology (the Helmet-CAM) and a regulated dust control technology (the Continuous Personal Dust Monitor) on factors within an STS including employees’ knowledge of, communication about, and use of technology to mitigate respirable dust sources. The results are presented in a way that first, addresses the overarching principles of meta-design STS including organizational participation, flexibility, and communication and second, examines how technology implementation processes differ when the organization is complying with a formal, higher-level requirement. Results show that a prominent focus on the social factors within an STS framework could help reduce unpredictability on the technical side and may improve communication within the system to help reduce adoption time, especially if and when accompanying a new, formal work process.

By D. Parks, A. Miller, M. McNinch, R. Jacksha

Each year, hundreds of mine workers are involved in machinery-related accidents. Many of these accidents involve inadequate or improper use of lockout/tagout (LOTO) procedures. To mitigate the occurrence of these accidents, new safety methods are needed to monitor access to hazardous areas around operating machinery, improve documentation/monitoring of maintenance that requires shutdown of the machinery, and prevent unexpected startup or movement during machine maintenance activities. The National Institute for Occupational Safety and Health (NIOSH) is currently researching the application of Internet of Things (IoT) technologies to provide intelligent machine monitoring as part of a comprehensive LOTO program. This paper introduces NIOSH’s two phase implementation of an IoT-based intelligent machine monitoring system. Phase one is the installation of a proof-of-concept system at a concrete batch plant, while phase two involves scaling up the system to include additional sensors, more detailed safety/performance metrics, proximity detection, and predictive failure analysis.

By H. S. Rathor

NTPC (National Thermal Power Corporation), a multi-unit organization, is generating 26% of India’s total power. This power is produced from its 14 coal based stations and 7 gas based stations. NTPC is entering into the business of power-distribution, power-trading, setting up of coal mines and diversification in non-conventional energy sector as well. For achieving the goal of the country “Power for All” NTPC has taken a giant stride by entering into Hydro Power generation which is also the cheapest and the cleanest renewable source of energy. In its pursuit for excellence, 800 MW Koldam Hydro Power Project is NTPC’s first venture in hydro sector. In Koldam, hydropower potential will be harnessed by constructing a 163m high earth and rock fill dam in a narrow gorge at upstream end of Bhakra reservoir. The river diversion is envisaged through two parallel, 14m finished diameter ‘horseshoe’ tunnels of length 901m and 934m at village Kian on the right bank, where the river forms a 180° loop. The diversion tunnels are designed to accommodate a flood of 6500m3/sec, taking into account the maximum probable discharge of 200 years return period. The tunnels pass through dolomite and limestone rock formations. The excavation of tunnels was done with drill and blast method. The excavation was attempted from both inlet and outlet faces. During geological investigation a rock fault was located at the outlet area. The location of the fault was such that it was passing through the edge of the Tunnel-1portal and around 30m away from the face of the Tunnel-2 portal. The quality of the rock at Inlet was also poor. To save the portals from slips, excavation of the tunnels was planned to start after the completion of the open excavation and its support system both at inlet and outlet. The tunnel excavation at inlet was envisaged by approaching the tunnels’ portal by constructing a road through 540EL bench and meeting the inlet portals on the upstream end, which would have been ready by mid2003, only after completion of the open excavation and its support system. To save time and cost, it was felt necessary to modify the planning by starting the tunnel excavation simultaneously along with open works both at inlet and outlet. The excavation at the inlet face of the tunnels started in December 2002 after rerouting the approach road to inlet portals through haulage road on the downstream and similarly Tunnel-1 at the outlet was started in the low cover area before completion of open area works. Thus the tunnel—heading excavation was started nearly 06 months early with the change of methodology.

Jan 1, 2005

By R. Guardia, J. Hoskins, E. Claros, Y. Kamiya, R. Ramirez, J. Dalenz, P. Fernandez, E. Ilgren

Crocidolite is a well known causative agent for mesothelioma. Studies have shown that the pathogenicity of the fiber from different mines varies considerably and it has been postulated the parameter that appears most likely to account for this variation is fiber width. Epidemiological studies have shown that ‘thin’ fibers from mining areas of Western Australia and the Cape Province, in South Africa are associated with a high mesothelioma risk while exposure to ‘thick’ asbestiform amphibole fiber of the same fiber type are associated with little or no mesothelioma risk. This study is concerned with ‘thick’ Bolivian crocidolite but similar findings also probably explain the paucity of mesotheliomas in the Finnish anthophyllite, South African amosite and African Transvaal crocidolite mines. The findings from the present study suggest the incidence of mesothelioma in the three major cities of Bolivia is not significantly elevated above background even though Bolivian crocidolite has been used for the past 60 years commercially and residentially in all three cities. Although some cases of mesothelioma may have been missed due to a failure to reach hospital or a shortened natural lifespan, mesothelioma generally occurs after the age of 50, we cannot tell precisely the extent to which these were confounding. We suggest the most likely explanation for the lack of mesotheliomas despite the large populations at risk from the long and extensive residential and commercial use of crocidolite containing products, is related to an increased fiber width distribution and a concomitant reduction in the ‘Stanton fiber size’ fraction.

Jan 1, 2012

By O. Nyandoro, K. Khoza-Shangase, M. Madahana, N. Moroe

"Occupational noise-induced hearing loss (ONIHL) is classified as the leading work-related disability in the mining industry. ONIHL has a negative impact, on not only the health and occupational productivity of affected individuals, but arguably also on the country’s mining industry and economy. Hearing conservation programmes (HCPs) are an effective strategy in the management of ONIHL. However, current literature indicates that HCPs are not achieving the anticipated and desired outcomes in the South African mining sector despite the efforts focused on the management of ONIHL. Therefore, the purpose of this study is to propose the use of a feedback-based noise monitoring model as a tool for monitoring and managing ONIHL in the South Africa’s mining sector. This model is a basic static feedback model with practical applications such as estimating, monitoring. and providing quantitative information to aid miners, mining administrators, and policy-makers in decision-making around HCPs. Additionally, the model could form part of an early intervention and management strategy for ONIHL in the workplace. The strength of this model, although currently static, is that it encompasses all the pillars of HCPs and takes into account the policies concerned with the management of ONIHL in the mining sector. IntroductionHazardous noise levels (above 85 dBA) in the workplace place exposed employees at risk of developing a disabling occupational noise-induced hearing loss (ONIHL). ONIHL is the ‘partial or complete hearing loss in one or both ears as a result of one’s employment’ (Nandi and Dhatrak, 2008, p. 1). This type of hearing loss develops gradually as a result of being exposed to continuous or intermittent high levels of noise over a long period of time (McBride, 2004; Patel et al., 2010; Rappaport and Provencal, 2001). A hearing threshold below 40 dBs is classified as a disabling hearing loss (Yadav et al., 2015), resulting in a hidden condition that does not readily manifest itself (Tye-Murray, 2009, p. 3). Dugan (2003) describes disabling hearing loss as the ‘most prevalent, least recognized and least understood physical disability’, while Copley and Frederichs (2010) and Hermanus (2007) argue that permanent disabling hearing loss is a major contributor to the global burden of disease on individuals, families, communities, and countries."

Jul 1, 2019

The objectives of this paper are to introduce the International Code of Practice for Risk Management of Tunnel Works and to illustrate to the participants of the 13th Australian Tunnelling Conference 2008 how the insurance industry would like to see the future of tunnelling insurance. Tunnel construction projects have suffered large losses over the years as can be shown from various loss examples and a list of major losses over the last ten to 15 years. Since the consequences of insufficient risk control had to be borne by insurers, these losses have heightened the need for improved and adequate risk management measures so that insurance cover can also in future be provided for this hazardous industry sector. Observations are made as regards to the prevailing trends in the tunnelling industry, which contribute to the increase in risk and have adverse consequences for the insurance industry. To find a solution to this dilemma various options are examined with the suggestion of a Joint Code of Practice for Tunnel Works being agreed by all stakeholders, which would become essential to secure future insurance protection for such project work. The British Tunnelling Society has, in cooperation with the Association of British Insurers, developed such a code, which the International Tunnelling Insurance Group has now adopted for global application in international markets. The content and concept of this code is explained to establish a framework of understanding and applied risk management principles for tunnel works. This initiative also has the support of the International Tunnelling Association and the International Association of Engineering Insurers. The international application of this new code is demonstrated with a few examples, which also includes Australian projects. It is the aim that this code forms in future part of the insurance coverage for tunnelling works in order to put this risk segment on a more sustainable basis. For that reason the insurance industry is seeking the support of all stakeholders of tunnelling construction projects.

Jan 1, 2008

By A. Roca, G. Ríos, I. Ruíz, M. Cruells

Flash Smelting Furnace (FSF) hot dust-laden is cooled in a waste heat boiler (WHB) and then dedusted in electrostatic precipitators (ESP’s) before being treated, together with the Peirce Smith Converters off-gases, in the sulfuric acid plants for SO2 removal. FSF dust is sulfated by SO2 and O2 in the WHB. Typically, 70% of the dust from the FSF drops in the WHB while the remainder is caught in the ESPs. The collected dust is recycled to the FSF for Cu recovery. Some smelters have developed hydrometallurgical treatments to recover Cu from the dust; impurities, such as As and Bi, are bled as leach plant residues. This paper presents a study (laboratory scale), of leaching the FSF dust, generated in Atlantic Copper Smelter using the weak acid bleed from the gas scrubbing/cooling section (GSCS) of sulfuric acid plants. Leaching was performed with 0.5 mol L-1 sulfuric acid concentration, 60ºC, and a solid/liquid ratio 1/3. After leaching, H2O2 was used for arsenic and iron oxidation. pH was adjusted for precipitation of arsenic and iron as scorodite or as scorodite and arsenical jarosite. The precipitation was carried out at 95ºC during 3-6 h. Liquids after precipitation are suitable for subsequent treatments of electrolysis. INTRODUCTION The copper smelter dusts are usually recirculated totally or partially to the flash furnace. This practice increases the amount of impurities feeding the furnace. Some authors have developed processes for treatment of these materials for copper and zinc recovery and for arsenic, antimony and bismuth inertization. The processes for the treatment of copper smelter dusts can be pyrometallurgical (Yu, 1987; Carter, Vance, Aldridge, Zaw, & Khoe, 1994; Fu, Jiang &Wang, 2000), hydrometallurgical, or mixed processes (Yin et al, 1992; Mulale, Mwema, & Mashala, 1999; Gorai, Jana, & Khan, 2002). Hydrometallurgical processes have been extensively studied and, in some cases, applied to an industrial scale. The most important chemical reagent proposed for leaching the dusts has been sulfuric acid (Roman-Moguel, Plascencia, Pérez, & Garcia, 1995; Gabb, & Evans, 1997; Larouche, 2001; Morales, Cruells, Roca, & Bergó, 2010; Cáceres, Cruells, Morales, & Roca, 2012; Ecometales, 2013; Yang, Fu, Liu, Chen, & Zhang, 2017). Processes developed in alkaline media, and in some cases with the presence of sulfide, have also been carried out (Gabler, & Jones, 1988; Morales, Hevia, & Cifuentes, 2009; Alguacil, Garcia-Diaz, Lopez, Rodriguez, & Alonso, 2013), as well as by using a bioleaching process (Massinaie, Oliazadeh, & Seyed Bagheri, 2006; Bakhtiari, Atashi, Zivdar, Seyedbagheri, & Fazaelipoor, 2011).

Jan 1, 2019

By A. Lane

The socio economic risks of mining in South Africa have been emerging for some time now, and have been brought into sharp relief by recent events in the platinum sector. The slow pace of social upliftment in the country has lead to widespread social unrest with consequent calls for different forms of resource nationalism. Fundamentally, the key stakeholders are not fully aligned, and are not engaging productively. This poses significant above-the-ground risk to mining companies. Measuring social impact, deploying inclusive solutions and engaging effectively with stakeholders are three ways in which mining companies can mitigate this risk.

Jan 1, 2013

By A. Lane

The socio economic risks of mining in South Africa have been emerging for some time now, and have been brought into sharp relief by recent events in the platinum sector. The slow pace of social upliftment in the country has lead to widespread social unrest with consequent calls for different forms of resource nationalism. Fundamentally, the key stakeholders are not fully aligned, and are not engaging productively. This poses significant above-the-ground risk to mining companies. Measuring social impact, deploying inclusive solutions and engaging effectively with stakeholders are three ways in which mining companies can mitigate this risk. Keywords platinum, mining, community, socio-economic impact, stakeholders, conflict, labour unrest, social licence to operate, investment, Africa.

Mar 1, 2013

By T. Holmes, J. Middlemiss

"Agnico-Eagle (AE) has been operating their Kittila Mine in Northern Finland since 2008. The mine has experienced considerable ore flow problems with ratholing, bridging and freezing in their mill feed bin since start up. In the first winter of operation, the entire central portion of the contents of the cylindrical flat-bottomed 2000 tonne mill feed bin froze. Flow was erratic and could only be achieved through small diameter ratholes. To maintain a reasonable, albeit limited, feed to the mill, the bin had to be kept less than ½ full and a portable steam generator was brought in to melt the frozen agglomerates that frequently blocked the outlets. The combination of limited surge capacity and frequent outages required the crushing plant to operate 24/7 and resulted in inconsistent production levels and high operating costs.AE had planned to expand the processing plant to increase throughput by about 30% when they transitioned from open pit to underground ore. These plans presented an opportunity to improve the material handling.To avoid the problems experienced with the original mill feed bin, AE enlisted Jenike & Johanson Ltd. (J&J) to test samples of the ore, and based on the measured flow properties to provide design recommendations to ensure that the new mill feed bin would operate reliably. The new 2000 tonne expanded flow mill feed bin and apron feeder were installed in 2014 and are now supplying almost 93% of the total mill feed with the remaining coming from the original bin.IntroductionIn early 2009, AE engaged J&J to visit their then recently opened Kittila mine and mill in Northern Finland (Figure 1). Over the first half-year of operation, production had been restricted in the ore handling and storage system by flow problems such as ratholing, bridging and freezing including blockages of chutes and hoppers as a result of frozen fines buildup and large frozen agglomerates. AE wanted to increase production in the existing open pit mine and mill feed operation and also wanted to avoid similar ore handling problems when they commissioned the new underground mining system under development at that time."

Jan 1, 2017

By S. K. Oraee

Managers always look for systems with minimum hazards. The hazards create problems for performance of projects. The largest and most important hazards of working underground mine can be related to health, safety and environmental, because if one of these sectors be in hazard, maybe lead to close mine. Failure mode and effects analysis (FMEA) is a widely used quality improvement tool to identify the potential failure modes for measuring reliability of a product or a process. FMEA is performed by developing a risk priority number (RPN), which is the product of severity, occurrence, and detection ratings. On the other hand, with regard to uncertainty in the decision-making, fuzzy theory will be able to model this uncertainty. Fuzzy FMEA provides a tool that can work in a better way with vague concepts and without sufficient information than conventional FMEA. This article by using Fuzzy FMEA and based on HSE criteria evaluate hazards of Parvade No. 1 Mine in Tabas Coal Mine. The results demonstrate the most hazardous parameter is rock burst in this mine.

Jan 1, 2011

By P G. Self, M D. Raven, R A. Eggleton

Investigation of an abandoned quarry near Rowland Flat in South Australia identified asbestiform antigorite as the fibrous serpentine mineral mined during the 1940s to 1978 for filler applications, not amphibole asbestos or chrysotile as reported in earlier investigations. Scanning and transmission electron microscopy (SEM and TEM) and selected area electron diffraction (SAED) of individual fibres were used to confirm the identification. Chrysotile is widely regarded as the only asbestos mineral in the serpentine group. Further work was done therefore, on the geology and mineralogy of the occurrence, and the health implications were reviewed. A zone of antigorite alteration, with associated talc, is traceable for 750 m along strike of recrystallised dolomitic siltstone within Woolshed Flat Shale of Neoproterozoic age. The antigorite formed, in part, by replacement of prismatic crystals of probable tremolitic amphibole. The deposit is proximal to the Williamstown Fault and the serpentine-talc alteration is possibly due to fluids expelled along the fault during late-stage deformation in the Early Palaeozoic Delamerian Orogeny. The antigorite comprises white to pale green bundles of lath-shaped fibres that occur either as randomly- arranged equant patches after amphibole or as cross-fibre veins, both intimately mixed with calcite. Highly fibrous product was mined from the weathered zone where calcite was leached during weathering. Gentle grinding releases fibres with a high aspect ratio (>10:1) that show a wide range of fibre thickness, including a significant proportion of fibres <0.25 ¦m width. Toxicological studies on fibrous antigorite from Poland and Italy indicate that the carcinogenic potential of this form of serpentine is similar to amphibole asbestos. X-ray diffraction (XRD) and fourier-transform infrared (FTIR) techniques readily distinguish antigorite from chrysotile. Determination of asbestiform habit and confirmation of antigorite mineralogy is most reliably done using electron microscopy, preferably with SAED capability.

Jan 1, 2008

By K. Donahue

Clay minerals play an important role in the gravitational stability of man-made rock piles by affecting geotechnical and hydrological characteristics of the material. The Goathill North rock pile at the Questa Mine in northern New Mexico has been the focus of a multi-disciplinary study to determine the effect of weathering on rock pile stability and in particular to determine if clay minerals are forming in the rock pile due to surface weathering. The results of x-ray diffraction (XRD) and scanning electron microscopy (SEM) analyses indicate the clay minerals found within the fine-grained soil matrix of the rock pile are of hydrothermal origins and did not detect any neoformation of clay minerals. The foremost mechanism for an increase in clay minerals within the rock pile is the physical break down of hydrothermally altered rock fragments to release hydrothermal clay minerals. The hydrothermal clay minerals within the rock pile show evidence of weathering by the dehydration of smectite from 2-water to 1-water interlayers within the clay mineral structure. This dehydration is most likely due to higher temperatures and low relative humidities in the Goathill north rock pile during surface exposure.

Jan 1, 2009

By J. E. McGill

The junior and small-scale mining sectors in South Africa play an important role in the livelihoods of numerous communities. Mining presents an opportunity, in the post-1994 democratic era, for many individuals to obtain access to much required empowerment and socio-economic development. These sectors are, however, not without numerous characteristics that pose problems for operators, legislators, and other role-players. Mining is inherently risky, with operators experiencing frequent difficulties and challenges throughout the life of mine. Opportunity exists, and needs to be enhanced, for junior and small-scale prospects and operations to include technical risk assessment techniques in documentation presented in search for funding, and in optimizing monthly planning and longer-term functioning. The focus here is to explore how the risk management cycle may currently be applied to a mineral resource suitable for exploitation by the junior and small-scale mining sectors. No management process can create additional value in the ground, but various available mechanisms can go a long way to quantifying the inherent risk that exists, highlighting the need to manage the risks and hopefully allowing the entrepreneur access to the intrinsic opportunities of the emerging mining sector in South Africa.

Jan 1, 2006