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By Walker. P. W. A.

Abstract -The Riviera tungsten occurrence in the Cape Province of South Africa was discovered in October 1979 as a result of stream-sediment panned concentrate sampling. The Cape age granite and late Precambrian Malmesbury Group carbonates and chlorite schists which it intrudes and which host the mineralization are covered by between 10 m and 30 m of Tertiary/Recent alluvium and clay. The scheelite/powellite and molybdenite mineralization occurs in a greisenized granite cupola with an overprint of porphyry-type alteration as well as in minor skarns. The ore reserve is estimated to be 46 million tonnes at an average grade of 0.2160Jo W03 and 0.020% Mo. The deposit is uneconomic at current tungsten prices.

Jan 1, 1994

By Seungyeol Lee

Currently, a new construction method using a robotic system is widely spreading in construction sites. This study is related to the design of glazing robot?s teach pendant which can improve convenience of handling and hence improve the productivity through the efficient interaction between an operator and a robot while doing glazing works, e.g., curtain wall installing. The suitability of selection and arrangement of control switches was assessed according to mechanical motions of a glazing robot, and design guidelines for improving convenience and productivity were drawn up through questionnaires carried out by site operators. To verify the proposed design guidelines, working time comparison of the proposed teach pendant and the existing teach pendant was executed.

Aug 1, 2013

By A. M. Ramadan

The composition of phosphate rocks, mainly used in manufacturing fertilizers, varies among deposits; therefore, phosphate rocks from different sources are expected to behave differently in acidulation processes. This paper examines the effect of preconcentration of phosphate ore from El-Sebaiya East, Egypt, using flotation on uranium leaching. A high-grade ore sample (27.3% P2O5, 168 mg/kg U) supplied by the Al-Nasr Mining Company, was subjected to reverse single-stage flotation to separate carbonate from the phosphate sample. Subsequently, P2O5 and U concentrations were 32.2% (92.1% recovery) and 225 mg/kg, respectively. After the leach process, the U concentration in the liquor was 319 mg/L.

Jan 1, 2014

By E. Viljamaa

In this research, earlier developed information integration method and novel web technologies are applied to intensify infrastructure construction process control. The applied method uses semantic methods to integrate scattered information that is later on exploited by process management using state-of-the-art web technologies. The applied method and web technologies not only improve the process management situation awareness by integrated up-todate multi-source process data but also provide platform independent access and visualization tool for process data. Utilization of such technologies potentially lead on cost savings, make processes safer and also more environmentally friendly. The integration method also enables intelligent queries to the integrated data making possible to use machine based inferring to the data.

Aug 1, 2013

By Lyle F. Smith

With the demand for larger diameter raises under all ground conditions and the increasing price of drill rods and operating costs, it was evident that there was a need for a raise borer with a variable-speed drive and fast-response torque limiting control. The raise boring machine described in this paper was developed after several years of market research and discussions with mine operators and construction contractors. This paper discusses the Ingersoll-Rand raise borers with the solid-state controlled DC motor drives. These machines have gained wide acceptance in the five-year period since being placed in operation and are designed to accommodate the range of raise diameters and lengths most required today.

Jan 1, 1978

By Paul T. Fitzgerald

Risk financing solutions are emerging to fully address environmental liabilities for mining operations. Supported by specialized insurance and alternative risk transfer (ART) products, mine owners can fund, cap and guarantee the environmental liabilities and closure obligations of a mine within a financial structure that will be acceptable to regulators. An environmental risk financing program will permit an owner to transfer the liabilities and indeed the ownership of a site to a third party that has the ability and resources to responsibly execute the closure plan. A properly structured program will be financially viable for the owner and will also respond to community and environmental opposition concerns about sustainable development and the environmental legacies associated with mining activities.

Apr 1, 2005

By B. H. Weber

"Industry generally has become noise-conscious and is realizing that damage to the human ear is expected to become more costly than any other compensation. Noise control has been recognized as a necessity and, fifteen years ago, in co-operation among different countries, inter-national organizations were set up to co-ordinate measures against dangerous noise and the development of silencing devices began. Rock drills for underground operations were particularly scrutinized because of the explosive nature of the noise developing from air escaping from exhaust. This paper describes the results and the present stage of development in the reduction and control of noise on rock drills, with special application to their use in mines."

Jan 1, 1970

By John F. Vynne

This paper will discuss several of the systems and processes that have been developed over the past few years, and are now being utilized by major mining companies on draglines in North America, Australia and South Africa. These technologies include production monitors and reporting systems, GPS navigation systems, structural integrity monitoring systems, structural analysis studies to increase the dragline RSLs, and inspection and response strategies. The use of these technologies provides significant increases in dragline production, and reduces maintenance costs and downtime. The question that needs to be asked is what value is there in monitoring? Increasing dragline productivity is dependent upon to two items with the overall goal being to maximize the number of bank cubic meters moved and to uncover more coal: 1) maximizing payload and 2) maximizing the number of cycles. If you do not measure and try to optimize the parameters that impact payload and number of cycles, there is very little chance that you can improve overall dragline productivity. These parameters are: Maximizing payload is dependent upon the following: ? Geology ? Blasting ? Monitor weighing accuracy ? Engage location ? Disengage Location ? Rigging ? Suspended load ? Bucket characteristics ? Operator skills ? Minimizing rehandle Maximizing the number of cycles depends upon maximizing digging time, and minimizing cycle and delay/down times by: ? Minimizing Operational Delays ? Minimizing Mechanical Delays ? Minimizing Idle time ? Minimizing Walking time ? Minimizing Fill Time ? Minimizing Swing Angle ? Maximizing Swing & Return Rates ? Minimizing Spot Time A third reason to monitor, conduct structural analysis studies, and have inspection strategies is to prevent catastrophic failures such as shown in the following photographs (figures 1 & 2).

May 1, 2008

By J. Roth

"While not taking issue with the general thesis expressed in Dr. Ridge's analysis of the role of genetic concepts versus observational data in ore exploration (Ridge, 1983), the criticism could be offered that the author tends to slight the importance of conceptual (i.e. theoretical) models in mineral exploration.As a general rule, observational data in science lacks significance and utility without a theoretical construct to organize those observations. Theory in turn dictates what observations are made-and which ones are judged important. Thus, for example, prior to the elaboration-and acceptance- of the current model for volcanogenic base metal deposits, the structural aspect s of these deposits were most closely observed and studied by explorationists. The nature of the enclosing rocks and any attendant alteration was given minimal attention, and certainly didn't figure prominently as an exploration guide.Similarly, the importance of alteration features to exploration for porphyry copper-molybdenum deposits was only perceived when a theoretical model was developed to account for these aspects. Indeed, many of these porphyry copper deposits were regarded as epigenetic vein deposits by geologists of an earlier era observing and examining on a different physical scale-and with a different theoretical bias.In constructing and evaluating such conceptual models, explorationists primarily rely on observation data and proximate associations; speculative thoughts as to ultimate provenance or crustal evolution clearly play a subordinate role, as Dr. Ridge argues. This, however, should not obscure the fact that concepts and theories do indeed exert a major influence in mineral exploration."

Jan 1, 1983

By Peter Babik

"Cable TV networks are extensively used throughout Canada for TV signal distribution. Mobile/portable radio communications are also used extensively throughout all sectors of industry. There are numerous manufacturer supplying these industries with a wide variety of equipment and accessories.IAL's underground radio communications system combines the techniques of cable TV and mobile radio to produce a flexible communications system with most of the advantages of both systems. Standard off-the-shelf mobile, portable, base-station and repeater equipment can be used. The equipment may need modification to be customized to particular end user requirements, but does not require a complete new unit redesign. Likewise, the cable TV distribution equipment is off the-shelf, with some items requiring modification for underground system application.Radio communications can be provided wherever the cable system is extended. Where traffic or type of activity warrants it, multiple radio channels can be provided on the same cable. Certain radio channels could also be used with data channels for control or supervision of remote equipment or environmental conditions. In addition, the same cable can be used to distribute or monitor signals from remote TV cameras in selected or dangerous areas. The system can be interfaced to a telephone system, if required, to provide extended communications to above-ground workshops, offices, medical stations or even hospitals and other emergency services.IntroductionReliable communications among personnel throughout an underground mine area have long been the dream and goal of various mine operations personnel. The system to be described was designed to meet this objective."

Jan 1, 1983

By Gordon E. Forward

Sustainable development in the mining and metallurgical industrial sectors can be implemented by two distinct groups: 1. The managers and operators of existing facilities ? working with industrial processes and systems that have been operating for many years, in some cases several decades 2. Those who are engineering and building new facilities or upgrades of existing plants. The focus of this paper is to look at approaches and tools available to bring sustainable development thinking and action to these two distinct areas. The paper will discuss: 1. The concept of working with existing facilities and processes to minimize waste and maximize product from a regional raw material/resource consumption perspective using By-product Synergy. The BPS concept has been carried out in Texas (TXI-Chaparral?s STAR Example), in Calgary, Alberta with Suncor assistance, in Montreal, Quebec with Noranda as project leader and currently in Ontario with Dofasco as industry champion. Successful outcomes are presented. 2. A new approach to designing greenfield facilities or upgrades to existing plants using a sustainable development review process. Undertaking the review early in every project can institutionalize the concept of discussing and implementing waste elimination, design for environment, eco-efficiency, risk minimization and community awareness and involvement in the future capital stock. The review process has been developed as an excellent tool for measuring and reporting on a corporation?s sustainable development progress. Examples of how this approach has been adopted in the mining and metallurgical industry, and the resultant outcomes are given.

May 1, 2002

By C. Tissot, R. Palmer

"Due to the low concentrations of gold, direct measurement of gold concentration in ore on belt has not been seriously considered to now. Pre-concentration or sorting strategies have largely consisted of particle sorting based on secondary characteristics such as colour, which can be successful in select cases. CSIRO has produced sample measurement results using gamma activation analysis of ~300 gm samples with accuracies of around 30 ppb at best. With this encouragement, a feasibility study into gold ore measurement on belt for the purpose of sorting pods of gold ore has been undertaken. The study described here included, prototype design options with existing industrial Linacs, extensive Monte Carlo modelling of measurement sensitivity and shielding, further sample measurement, a study of the interaction of target measurement accuracy and sorting efficiency, and a rough estimation of potential economic benefit. The projected model sensitivity of around 0.1-0.15 ppm (1 standard deviation) in 10 seconds for 1 ppm average feed result in good bulk sorting performance and intriguing economic potential.INTRODUCTION Pre-concentration or sorting strategies for gold ores have largely consisted of particle sorting based on secondary characteristics such as colour or density, which can be successful in select cases (Klein, 2010). No method is available to measure gold content for sorting in particles or even in bulk on belt, principally due to the low concentrations of gold present. In fact, in many cases it is difficult to do rapid bulk grade measurements of base metal ores with concentrations many orders of magnitude higher. By a fortunate quirk of nature gold is particularly amenable to gamma activation analysis (GAA). CSIRO has performed extensive work in GAA of samples of crushed ore (Tickner, 2017). This has resulted in the Photon AssayTM technique that is currently being commercialised through the CSIRO spinoff company Chrysos. The technique relies on the recent availability of industrial high intensity X-ray sources such as Linacs which are currently being used in industry for security, medical and sterilisation applications. This development has led to CRC ORE funding a feasibility study to determine whether on-belt measurement of gold concentration is possible at a rate and accuracy sufficient to be useful for bulk sorting, where pods of ore are diverted rather than individual rocks. The study in the first instance is based on Monte Carlo modelling that has successfully predicted the performance of the sample based gold measurements. As well as the measurement feasibility consideration was also given to the likely heterogeneity of gold ores and hence the degree to which useful separation could be achieved. This is then tied to a back of the envelope evaluation of the order of magnitude economics of bulk sorting in an example deposit."

Jan 1, 2017

By Robert White

?Introduction of BMS?Paste fill generalities?Development through paste?Development through rock fill?Conclusion ?Brunswick mine is operated by Xstrata. The mine has been in operation since 1964 and produces around 10 000 tons per day of ore containing (in order) zinc, lead and silver? The ore body consists of close to ten sub-parallel massive sulfide lenses. The length of the ore body is 1200 m with a width of up to 200 m. From the surface, the ore body extends to a depth to 1200m ?There is 100 km of active drifts for a total 400 km ?The mine is divided by 7 levels and 23 actives sub levels

Feb 1, 2008

By P. MacPhail, G. S. Dobby, I. M. Flint

"The objective of the laboratory work described in this paper has been to develop a method f or producing small gas bubbles at moderate to high gas rates in a flotation column. Small bubbles are particularly important for attaining reasonable flotation rates of fine particles. An ultrasonic aerosol generator has been employed to add frother solution directly to the gas stream. Using porous glass and filter cloth spargers, aerosol frother addition has produced bubbles at 1/2 to 2/3 the diameter of those produced by conventional frother addition to the liquid, at a lower frother consumption.IntroductionGas bubbles are generated in a flotation column most commonly by forcing gas through a porous medium called a sparger. Typical sparger material includes rubber (pierced with small holes) , fabric (such as filter cloth), fritted glass, or porous metal (steel or bronze) . Solid sparger material is suitable for laboratory use; however, for industrial applications a flexible sparger such as rubber or fabric is necessary to prevent the eventual plugging of orfices with solid particles and/ or precipitates. An exception to this is the use of a gas liquid contactor external to the column in combination with pressure release of gas in water, a method that has been demonstrated to produce very small gas bubbles. The typical objective of bubble generation for flotation column purposes is to produce bubbles with diameter of about 0.1 cm (and less) at a gas superficial velocity of 1 cm/s to 3 cm/s. In general, the smaller the bubble, the better. In man y cases, though, there is little , or nothing, gained by generating bubbles less than about 0.05 ern in diameter.Several factors affect bubble size when generated by a sparger: gas rate, orifice diameter, sparger surface area, surfactant type, surfactant dosage, and static head. At very low gas rates bubble diameter is independent of flow rate and is proportional to orifice diameter. At the moderate gas rates encountered in flotation columns bubble diameter, db' is related to gas flow by: db oc vg n, where vg is superficial gas velocity (rate of gas flow per unit column area). For porous steel and filter cloth, n has a value of about 0.25 for vg between 0.2 cm/s and 2 cm/s(2). The magnitude of the effect of orifice diameter at these gas rates is unclear. The effects of frother type and concentration on bubble size issuing from a single orifice have been measur ed by Miagkovaru , shown here in Figure I(IS). The reduction in bubble diameter upon surfactant addition is due to the lowering of interfacial tension created by adsorption of surfactant at the gas liquid interface."

Jan 1, 1988

By George Hope, Dave Green, Jacques McMullen

The Est Malartic mill has been treating massive sulphide, copper/gold ore from the Bousquet 2 mine since 1989. The need to minimize copper content in flotation tails which are leached for gold recovery and to produce a saleable copper concentrate led to the evaluation of Conventional, Column and HG flotation methods. The HG method was preferred and two full-scale cells were installed and operated over a two-year span. In 1992, it was decided to expand the mill capacity from 1500 tpd to 2500 tpd. A total of nine additional HG Tank Cells were installed to provide additional roughing and cleaning capacity. The expanded plant has been operating since June 1993.

Jan 1, 1994

By Cheryl L. Allen

The power required to operate a ventilation system can be 25% to 50% of the total energy requirements of a mine. In an effort to reduce energy consumption, initiatives are being introduced at Vale Inco to increase the efficiency of ventilation systems with the objective of decreasing energy usage. One energy conservation measure being introduced is the use of variable frequency drive (VFD) technology for fan motor control. Advancement in technology is making VFD applications more of a standard in industry. The benefits include improved operating performance and system control, reduction in current peak demand, and optimized power usage. This paper describes the application of VFDs for main and auxiliary mine fans; and associated potential energy savings.

May 1, 2009

By Mikael Ramström

In 2002 Atlas Copco Rock Drills AB released the new RCS technology for all of its drill rig types. RCS opened the way for a new generation of computerized drill rigs based on modern, standard PC-computer technology. Drilling accuracy, information logging and reduction in manpower in some types and serviceability, have all taken a quantum leap forward when compared with previous generations of drill rigs. The RCS (Rig Control System) is modularised and distributed is accomplished by means of CAN-bus technology. This technology, which is well proven in automobile applications, forms the communication backbone of the rig. The modularity facilitates almost unlimited possibilities for the expansion and adaptation of drill rig functions.

May 1, 2003

"Process specifications for classification system design f or closed circuit grinding are identified. A computer-assisted, mass balance procedure for estimation of material size distributions and required hydrocyclone separation performance is presented.GeneralClassification equipment application involves a large number of variables, but can be greatly simplified by consideration of the following two major steps:(A) Process analysis, in which the so lids and liquid material balances and solids size distributions in the three classifier streams are determined in order to establish the required classifier separation performance.(B) Equipment selection, in which the cyclone dimensions and feed conditions are selected to yield the de sired separation, and the number of units then determined by their capacity rating."

Jan 1, 1984

By Fathi Habashi

A new era in pressure hydrometallurgy is marked when the roasting - leaching - electrowinning process in the zinc industry was replaced by direct pressure leaching of zinc concentrate. Since then, the technology has received recognition as the technology of the future. Large autoclaves of unprecedented size have been manufactured and installed in a number of metallurgical plants for recovering copper and nickel from their concentrates or liberating gold from its refractory ores. An attempt to recover alumina from clay using pressure technology is underway. Autoclaves lined with acid resisting bricks or with titanium clad may weigh as much as 800 tonnes were transported successfully from the manufacturing workshop to the mine site over long distances.

Jan 1, 2014

By D. Moffat

Rio Algom Limited has mined uranium at Elliot Lake, Ontario for 20 years. The production of this energy-generating element results in the need to dispose of low-level radioactive solid wastes and liquid effluents. Because of the wet-temperate climate at Elliot Lake, the liquid effluents are of particular importance. Radium-226 is the isotope which requires most attention, and the current practice for its control is by addition of barium chloride and retention of the resultant precipitates in large settling ponds. Analyses of typical effluents and waste streams are discussed and typical levels of radium-226, thorium-230, thorium-232, thorium-228, lead-2iO, polonium-2iO, and uranium isotopes are presented.

Jan 1, 1979