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By J. Kazakoff

"The success of gold recovery at the Jolu gold mill depends on many variables. The most important ones are the people, the ore body, plant design parameters, equipment selection and cost control. This paper will briefly hiqhlight the above, the main focus, however will be on the gravity gold circuit.The gravity circuit requires judicious operator attention in order to operate properly. In return the circuit gives immediate visual results for mill peopleIntroductionThe development of the Jolu property to the production stage was carried out quickly, efficiently and economically. The property became a gold producer ahead of schedule and under budget.The Jolu property is a joint venture between International Mahogany Corp., a 70% partner, and Corona Corporation, a 30% partner. Corona Corporation operates the Jolu Gold Mine, located 140 kilometers north of LaRonge and 520 kilometers north of Saskatoon."

Jan 1, 1990

By J. H. Archibald

"IntroductionShot-saws are used for sawing rock throughout the dimension stone industry especially in granite quarry mills. Shot-saws, as currently designed, have an inherent wear problem which leads to slow cutting rates and repetitive blade changes which consumes much time. Because the saw blades are made from steel the abrasive shot used with them is limited to a certain hardness which effects the over-all efficiency of the sawing operation. Suggestions are made toward optimization of blade design and the sawing process. Blade DesignA common steel blade design is shown in Figure I. Note the perforations in the blade. These perforations or holes in the blade serve two or three purposes. The most obvious reason is to allow the abrasive shot a pocket in which to collect at the bottom of the blade, so that it can be distributed from these pockets into the cutting zone underneath the blade. The abrasive is fed to the saw in a slurry and usually comes in from the top. The blade must then cut a kerf wider than itself in order that the abrasive grains have a path leading from the top of the blade, down along its sides, and finally reaching the pockets and cutting zones. This circuitous path followed by the abrasive leads to side wear on the blades and high friction which can lead to blade buckling in severe cases. However, the fluidized path of the abrasives down the sides of the blade serves another purpose which is a positive gain if conditions are properly controlled. The abrasive slurry interacts with the perforations of the blade, the blade itself and the rock. This gap and the perforations in the blade, which are fluid filled, are sites of constant shearing motion. Eddy currents form in these gaps and pockets which tend to stabilize the blade by setting up balanced hydrodynamic forces which otherwise might not form in a non-perforated blade. A stable blade produces a more uniform cut in the rock. The third and final reason for the perforations are to allow the blade to wear in such a fashion that new pockets are always being formed and, consequently, new cutting surfaces between these pockets are also formed."

Jan 1, 1993

By A. Saigal

A finite element analysis based investigation using DEFORM software was undertaken to model the extrusion of 15% alumina and 15% silicon carbide reinforced aluminum metal matrix composites. The study dealt with predicting the extrusion load as a function of ram displacement and initial billet temperature. The finite element simulation was also used to determine the maximum extrusion load, temperature distribution, maximum temperature, strain rate, velocity and stress distributions in the billet during the hot extrusion process. The constitutive equation used was of the type: Z = E exp(Q RT) = A{sinh(ao-)}" where Z is the Zener-Hollman parameter (temperature compensated strain rate), s is the strain rate, Q is the activation energy, R is the gas constant, T is the absolute temperature, a is the flow stress and A, a and n are constants. Based on the work of Davies et al and McQueen and Konopleva, the values of Q (KJ/mol), a (MPa-1), n and A for aluminum 6061 composites reinforced with 15% alumina and 15% silicon carbide used are 181, 0.024, 4.15 and 1.33x10'2 and 233, 0.052, 2.60 and 1.26xl0'4, respectively. Even though the individual parameters are quite different, it was found that the predicted maximum extrusion load, temperature distribution, maximum temperature, strain rate, velocity and stress distributions are quite similar and differ by no more than 1-2 percent between the two composites indicating that the deformation behavior is primarily controlled by the matrix material and is not a function of the type of reinforcing ceramic particulates.

Jan 1, 2004

By E. I. Robinsky

"This paper describes a new, proven approach for tailing disposal. Not only is the disclosed system less damaging to the environment, it is also less costly to operate, to close down and maintain in perpetuity. The basic concept is to discharge thickened tailing from one permanent location.This creates a conical or hill-like deposit which:(1) requires lower perimeter dykes for equivalent storage capacity;(2) eliminates decant towers and decant lines;(3) requires no steep dams built of tailing;(4) is stable:(5) requires only a small pond outside the deposit;(6) decreases pollution of the surrounding environment by water seepage and deflation; and(7) simplifies abandonment and ""closing-down"" operations.The approach is made possible by the fact that, at a sufficiently high ratio of solids to water, tailing material can be made to accumulate at slopes of 5 or 6 per cent -- considerably steeper than possible by traditional methods using low solids-to-water ratios. To achieve the necessary solids-water ratio (35 to 60 per cent), it may be necessary to install a thickener. It is expected, however, that at many concentrators it may be possible to discharqe relatively clear plant water through a line separate from the tailing line, thus reducing the load on the thickener."

Jan 1, 1976

By J. Patterson

"Acid Mine Drainage (A.M.D.) formed from oxidation of disposed pyritic wastes presents a potential pollution hazard for Equity Silver Mines Limited and the mining industry in general. Failure to collect and treat these acidic effluents can eventually affect the quality of receiving streams and endanger aquatic life forms. Treatment and discharge of A.M.D. to the receiving environment must comply with stringent anti-pollution laws.Wastes mined at Equity Silver Mines Ltd. are predominantly acid generating and must be handled according to a materials management plan to minimize impact on the environment. Effluent collection and treatment facilities have been constructed to address the short term environmental concerns with reclamation and research programs being developed to address and monitor abatement measures for control over the long term.The purpose of this paper will be to offer a brief overview of these measures. Key topics for discussion will be: kinetics of Acid Mine Drainage, acid generating potential, water treatment and sludge handling, special wastes, waste dump construction, waste rock amendments, bacteriocide research, simulations, and reclamation measures. Programs designed to evaluate impact on the receiving environment, although they form an extensive part of the program, will not be discussed in this paper.INTRODUCTIONEquity Silver Mines Limited is located in the Central Interior of British Columbia, within the Omineca Division, 35 kilometers southeast of Houston Mining and approximately 575 kilometers by air north-northeast ofVancouver (Figure 1).The deposit consists of three economic mineralized zones: The Southern Tail, Main and Waterline Zones. Mining of the Southern Tail commenced in April, 1980 and was completed in the first quarter of 1984. Main Zone production was initiated during the last quarter of 1983 and the Waterline Zone remains undeveloped to-date. Remaining reserves are in the order of four years contingent on favourable metal prices. The three deposits (Figure 2) occur within a window of interbedded volcanic and minor sedimentary rocks. The older volcanic sequence is bounded on the west by a small granite-like stock and on the east by a gabbro-monzonite complex. All are overlain by a series of younger lava flows."

Jan 1, 1988

Geology grads mine heated job market Salaries up 44 per cent in three years ?[Geology student] passed up a $100,000-a-year job at a mining company last December when he finished his degree in geology. The 24-year-old Canadian said he?s confident he?ll get a better offer.? Rob Delaney and Stewart Bailey, Calgary Herald, Published: Saturday, March 15, 2008 Massive shortages across the mining industry > Trades and operators are a large component > Technical people are equally hard to find > Students are in an excellent positions to secure exciting jobs > Experience is at a premium. Why?

May 1, 2008

By A. J. Neale, B. C. Flintoff

"In most mineral processing operations the term audit is usually reserved for the exercise of checking financial records and/ or safety practices. While these activities are time consuming, no one disputes their necessity or value. If we subject these areas to such careful scrutiny, why is it that we don't normally apply the same principles to critically examine process operation. After all, the operating efficiency of the plant impacts directly on the measures of profitability.A mineral processing plant is a complex system that has a number of distinct, but mutually dependent elements: process equipment, instrumentation, operating policies, maintenance policies, control strategies and people. To ensure maximum economic performance, in the dynamic environment that characterizes a concentrator, requires a periodic review of each of these areas. However, to be useful, the study must be based on sound metallurgical principles and be conducted in a highly focused manner. Experience teaches us that the exercise is very revealing and potentially very rewarding.This paper will discuss the process audit process and illustrate its potential value through illustration taken from plant studies.IntroductionThe last twenty years have seen tremendous technological and organizational changes sweep the minerals industry. Process control systems, on-stream analyzers, and gold recovery techniques barely conceived twenty years ago are now incorporated in virtually all new installations in an effort to maximize operating efficiencies. In conjunction with these developments, changes in the way plants are managed, down-sizing of technical staff, reduction in the size of operating crews, and the flattening out of the management structure have significantly reduced operating costs. As a result, plants are making more efficient use of our natural resources, minimizing the costs of production, and in turn maximizing operating profits. Or are they?"

Jan 1, 1991

By Augustine O. Orumwense, Micheline Boisclair

"The use of stirred mill to complement tumbling mills in grinding fine grained minerals is increasingly becoming an attractive processing option. Parameters such as agitation speed, grinding media type and size, feed pulp density, and grinding time were studied in order to elucidate their impact on stirred milling. Test results showed that the parameters have a profound effect on stirred mill efficiency and operating cost. A comparative test with a tumbling ball mill was also made and the specific energies of both mills in fine grinding were analyzed. A difference of over 40% in energy savings particularly when the product size is smaller than 20 µm was obtained with the stirred mill.INTRODUCTIONIn industrial processes where very fine and ultrafine particles are required such as in chemical, ink, food, paint and lacquer, pulp and paper, plastics, pharmaceutical, metallurgical and ceramic industries, the use of stirred mills for grinding is well established. Mineral processing plants are gradually shifting focus to the use of stirred mills for fine grinding and /or regrinding purposes as the target liberation size gets very small. A number of plants processing finely/sparsely disseminated ores are known to have adopted stirred milling technology for their fine grinding needs (Enderle et al., 1997; Harbort et al., 1999; Gao et al., 2000; Davey, 2003 & 2006; Pease et al., 2006).There are different kinds/designs of stirred mills available on the market but, all can be divided into two sub groups namely fluidized and non-fluidized types. The non-fluidized stirred mills consist of Tower mill, Vertimill, Sala agitated mill (SAM), and ANI-Metprotech (SVM). These mills are characterized by their low-speed and the use of fairly coarse grinding media size, 3 – 20 mm. Hence, they are mostly suitable for relatively coarse grinding application. The fluidized type includes the Isamill, Netzsch mill and Stirred mill detritor (SMD). These mills have a characteristic high agitator speed, use fine grinding media size of 0.5 – 5 mm, and are employed in very fine grinding operations. The superior fine grinding capability of stirred mills is attributable to two main process parameters, which are the use of fine grinding media and a high mill speed."

Jan 1, 2008

By P. R. Day, W. K. Webster

"The introduction of large boreholes underground initially involved taking the techniques of open-pit bench blasting to the production stope, but with deeper boreholes and narrower stopes more controlled techniques must be developed in order to maintain good stope walls and prevent dilution of ore or structural damage to pillars due to blasting overbreak. The points discussed are drilling accuracy and drill pattern, the relationship between open-pit wall control and underground mining, the varied explosives products and initiation devices available, and some of the many ways that variations in loading, such as deck charging, etc., can produce desirable results.IntroductionThe use of large-diameter blastholes for underground mining began ten years ago and today they are widely employed in a variety of orebodies and stope configurations. These big blastholes, which range in size from 4.5 to 8 inches in diameter, were originally employed in the same manner ' as open-pit bench blasts; that is, the stope was silled out to full width and all holes were drilled vertical and parallel. This was suitable for competent, massive orebodies, however the popularity of the big drills saw their usage in more narrow stopes, often with poor ground conditions. The dipping orebodies and small drill sublevels resulted in inclined drilling.Today, there is full-ring drilling of 4.5-inch holes. Some 6.5-inch holes are drilled up to 350 feet deep. A 350-foot borehole may contain 6000 to 7000 pounds of explosive. The detonation of this size of charge weight within the confines of an underground stope can have considerable effect on the stability of stope walls and adjacent pillars. Obviously, precautions must be taken to minimize the damage which would result from the large charge weights possible with these big boreholes."

Jan 1, 1982

By Rob Barber

This paper shares the experience of the Alberta Energy and Utilities Board (EUB) Field Surveillance Branch over the past few years in building relationships with Aboriginal communities. Our goal is to provide and encourage best practices that may benefit you and your organization and result in strong, mutually beneficial relationships with a focus on Aboriginal communities. Historical information provides insight that aids in establishing effective working relationships with Aboriginal communities. An important component is appreciation of the perspective of these communities, which is achieved through awareness training. The use of local Aboriginal resource people as part of the training is recommended. A plan that is supported by management and staff is essential and lays the foundation for successful relationships. However, the plan must be flexible enough to change as circumstances warrant. The concept of having local people in communities address local issues is essential. This ?grass roots? approach, combined with the goal of exceeding a community?s expectations with respect to addressing issues, will go a long way to establish trust and credibility. Measuring the effectiveness of this work is the final building block to complete the picture.

May 1, 2004

By David Rahal, Des Erasmus, Ken Major

"Over the past twenty years there has been an increased emphasis on fine grinding in the minerals industry. This spurred the development of a range of new fine grinding equipment in the 1990s. At that time, the Knelson-Deswik mill was developed in South Africa for the pigments industry.Knelson Milling Solutions currently offers a wide range of laboratory, pilot and production scale mills. These mills bridge the gap between traditional low speed vertical mills and the high speed horizontal mills (tip speed < 3 and > 15 m/s respectively). They are designed to run at tip speeds between 10 and 12 m/s and are capable of operating with very dense grinding media. The result is a power intensity that is higher than the low speed mills and overlaps that of the high speed mills. This allows the mill to be customized for a wide range of grinding applications.A case study at Aquarius Platinum’s Kroondal Mine shows that the Knelson-Deswik technology can produce a consistent product size despite feed variations. It also shows that the throughput was proportional to the slurry density at Kroondal. The case study identified increasing the slurry density as a process change that can increase throughput and reduce the specific energy consumption.INTRODUCTIONThe increasing complexity and finer grain sizes of modern ore bodies have increased the importance of effective mineral liberation in obtaining acceptable grades and recoveries (Jankovic, Valery and La Rosa, 2003; Lichter and Davey, 2006; Napier-Munn, Morell, Morrison and Kojovic, 1996). This trend has increased the significance of fine grinding technology because the input energy increases exponentially as the required product size decreases from 100 to 10 microns (Gao and Weller, 1993a).The US Department of Energy recently provided the context for the potential energy savings in the US Mining Industry (BCS, 2007). They reported that grinding consumes approximately 494 TBtu/year. This was over double the consumption of the second highest equipment category, diesel materials handling systems (211 TBtu/yr). The proportion of grinding energy allocated to fine grinding can only be expected to increase as finer ore deposits are mined. It is therefore critical that fine grinding efficiency continue to improve through the selection of appropriate equipment and the development of best practices for existing applications."

Jan 1, 2011

By Nilce Alves Santos, Vânia Lúcia de Lima Andrade, Keila Lane Carvalho Gonçalves, Harold Wyslouzi1

"When confronted with the difficult decisions on advancing an exploration project to the feasibility and construction stages, it is important to know how various regions of the ore body will react in the milling and concentration processes. While bench scale test work is common and inexpensive, the results and information provided are somewhat limited due to the difficulty in accurately predicting the effects of recirculating middling streams or gradual changes in solution chemistry.Conventional Pilot Plants, processing 100 to 1,000 kg/hour of sample ore, provide the detailed engineering data required to develop a final process flowsheet and to size the equipment. They are, however, expensive to set-up and operate, and are really only viable for major projects that are well advancedIn the latter part of 1999, the Mineral Development Center at CVRD (MDC) purchased a new piece of mineral processing equipment which can run continuous flotation tests using drill core samples. To evaluate its performance, and to compare it with conventional testing methods, various types of flotation tests were carried out using two different types of copper ore. The limitations and advantages of open circuit and locked cycle bench tests, as well as the Mini Pilot Plant and the Conventional Pilot Plant were evaluated.Open circuit tests carried out at the bench scale only provide basic information. More complete and trustworthy information is obtained, in terms of the recirculation of flows and reaching a permanent and stable flotation regime, as the dynamics and complexity of the tests increases. The data obtained showed that the MPP’s metallurgical performance was equivalent to that of a conventional pilot plant."

Jan 1, 2002

By Bill Almdal

Today?s presentation ? Role of the Regional Issues Working Group ? What does RIWG do? ? How can RIWG?s work benefit Stakeholders? ? Review of forecasts vs. reality ? How have past investment compared to the reality? ? Risks to future growth ? The growth potential is very high and so are the risks ? Examples of outputs ? Housing needs ? Growth in population ? Tires for large trucks The Regional Issues Working Group ? Our vision ? To provide a proactive process which promotes the responsible, sustainable development of resources within the Regional Municipality of Wood Buffalo for the benefit of all stakeholders ? What we do ? Facilitate planning for growth ? Facilitate effective and efficient resolution of issues ? Involve all of the resource developers and affected stakeholders in planning ? Develop plans for sharing benefits with Aboriginal stakeholders ? Benefits for Stakeholders ? Our forecasts include up-to-date information from all developers ? including information on employment and housing needs ? Our forecasts are the basis of planning for many stakeholders ? and can assist in their development planning

May 1, 2002

By D. M. Wyslouzil

"Micron or sub-micron size gold inclusions in sulphide minerals cannot be extracted by conventional cyanidation. The gold surfaces must first be exposed by decomposition of the sulphides. As an alternative to roasting, pressure oxidation was found to be a most satisfactory method to decompose the sulphides and expose the gold particles. For cyanidation the pressure oxidation pulp has to be neutralized and stabilized with lime. It was found that thiourea can extract the gold directly from the pressure oxidation pulp without pH adjustment and oxidant addition. The main obstacles against the common use of thiourea are circumvented by a recently described control method of the emf during leaching.INTRODUCTION Amalgamation and cyanidation are the most conventional processes for gold extraction. The prerequisite for gold extraction is the possibility of gold surface to be contacted by mercury or by the cyanide solution. Encapsulated gold has little chance of contact and this leads to poor extractions.The reasons why a gold ore may be refractory are: micron or sub-micron size gold particles included in the sulphide minerals, such as pyrite and arsenopyrite; presence of and association with antimony, arsenic, tellurium and carbonaceous minerals. Some alternative processes, such as double oxidation(1,2), pretreatment with lime , H202, chlorine and Caro's acid, roasting and thiourea leach, have solved some of the problems of ""refractory"", but the sub-micron gold in sulphide minerals still shows little response. Roasting and the cyanidation of the calcine was one of the most successful approaches for this type of gold ore.There are two disadvantages to the roasting process: (1) the generation of sulphur, arsenic, antimony and mercury containing gases is undesirable and the control is extremely expensive; (2) gold particles might be fused in the roasted product and the oxidized base metals in the calcine might reduce the cyanidation efficiency. In recent years the pressure oxidation process has been considered as one of the more effective and satisfactory methods to decompose the sulphide minerals and expose the gold surface to the cyanide leach solution. The pollution problem could be better controlled and the gold extraction is more amenable."

Jan 1, 1985

By L. Lui, A. Cauchon, A. R. Laplante

"The gravity circuit at Les Mines Camchib Inc. consists of two pinched sluices to bleed a feed to one of two 76 cm (30"") Knelson concentrator. The Knelson concentrate is upgraded to smeltable grade with a smaller Knelson (18/30 cm) and a riffleless table. Their tails are column cyanided and washed prior to recycle to the grinding circuit. This paper details size-by-size circuit performance. The Knelsons recover around 90% of free gold (as determined by Mozley Laboratory Separator), even below 37 µm. The sluices are ineffective, with upgrading ratios around 2, but approaching unity in the fine sizes. Much of the effectiveness of the circuit lies in the high gold circulating loads in the grinding circuit, which partly atone for the poor sluice performance, and the ability of the Knelsons to recover free gold. Secondary upgrading recovers slightly above 99% of the primary concentrate gold, 90% of it in a 65% Au concentrate and the balance in a heavily loaded (10 to 20 oz/st) pregnant solution. INTRODUCTIONBackgroundThe operating performance of the mill of Les Mines Camchib Inc. has been described earlier (Laplante et al., 1989). The presence of significant chalcopyrite (1 % and up) makes flotation necessary prior to cyanidation, to limit cyanide consumption and minimize environmental impact. In 1982, the presence of very high gold circulating loads in the grinding circuit lead to the commissioning of a gravity circuit, schematically shown in Figure 1. Gravity recovery of gold has been found beneficial because it increases metallurgical recovery by 1-3% (Laplante et al, 1987), as only part of the flotation tail is cyanided, and economic recovery, because of the lower net smelter return of gold in the flotation concentrate (as compared with the gravity concentrate). The latter increase is estimated, with a net smelter return of 95%, at 1.5% when gold recovery by gravity is equal to 30%. In early 1988, a sampling program was initiated to characterize the behaviour of gold in the grinding/gravity circuit. This paper reports on the results of this study."

Jan 1, 1990

By Brad Wells, Wayne Bull, Wayne Dickinson

"Antiscalants were evaluated for control of calcium carbonate (CaCO3) in gold processing applications. Under severely supersaturated conditions, 100 percent inhibition was achieved with 30 ppm antiscalant. Laboratory and field testing established that an antiscalant could both inhibit scale buildup and remove an estimated 0.5 kg/m2 per annum of pre-existing scale. A program was developed to control CaCO3 at a gold mill experiencing severe scale buildup. Annual accumulation of as much as 3 cm of scale in process piping was reduced to unmeasureable levels when 10 ppm antiscalant was applied. No scale-related upsets in mill operation occurred during a five-month trial period.INTRODUCTION Inorganic mineral scale is a crystalline deposit that forms when dissolved mineral constituents exceed the solubility of the respective mineral phase. Formation of mineral scale adversely affects a wide range of industries and is of particular interest in mining and metals processing. Scale affects numerous stages of metal extraction processes. Restricted flow in piping, nozzles, valves, screens, pumps and other components used to transport mineral slurries, metal concentrates, and tailings as well as scale in millwater and thickener overflow circuits are primary concerns (Alfano & Boffardi, 1994). Heap leaching, comminuation, flotation, vat leaching, carbon adsorption, and heat exchangers as well as oxidation steps used in processing sulfidic ores are among key unit operations that may be adversely affected (Simmons & Gathje, 2003). Antiscalant chemicals are designed to prevent formation and growth of mineral scales such as CaCO3. These chemicals, which include two primary classes – phosphonates and anionic carboxylate polymers and copolymers - are added to the gold processing stream at low parts-per-million (ppm) concentrations to interfere with nucleation and growth of scale forming crystals and to disperse fine particulate material. Application points may be located throughout the gold extraction process. Evaluation of the performance of antiscalants plays a critical role in determining the best product for a specific application. Performance evaluations include laboratory testing, pilot scale studies, in-plant trials, and ongoing performance monitoring during mill operation."

Jan 1, 2014

By S. McAlister

"Falcon Concentrators Inc. has developed a high capacity centrifuge for the recovery of fine, free gold as well as other metals and minerals which were previously thought to be unrecoverable by gravity means. Development started in the early 1980's and the first commercial operation was commissioned in 1986. Gold applications include scavenging conventional gravity and cyanidation circuit tailings, cleaning gravity concentrates, cleaning flotation concentrates to melting grade, scavenging flotation tailings, and placer mining. Recent development work by Falcon has expanded the applications scope of the centrifugal concentrator to include many minerals amenable to gravity concentration including iron, tin, industrial minerals, and hazardous wastes. This paper discusses this technology including its history, present applications, and future potential. OVERVIEW OF CENTRIFIJGAL CONCENTRATIONUsing centrifugal force to enhance the separation of materials by differential specific gravity has been researched for over a century. Many attempts have been made to concentrate minerals in high gravity fields. Patents were granted on this subject as early as 1891 (see Figure 1). Patenting activity continued into the 1920's and has been relatively quiet since. It is significant that no centrifugal system of gravity concentration has been broadly accepted by the mineral processing community until recently. Much of the world's reserve of mineral deposits which are amenable to conventional gravity concentration technology (coarse-grained) have been mined and therefore there is an increasing demand for technology which can economically recover the fine-grained gravity recoverable minerals in the remaining deposits. In addition, centrifugal concentration can play an increasing role in solving environmental problems by offering an inexpensive method of concentrating hazardous materials such as uranium, plutonium, mercury, lead, and other heavy metals. The overall cost of disposing of these substances safely can be drastically reduced if they are recovered into a concentrated form prior to disposal."

Jan 1, 1992

The Stability Graph Method is widely used in Canadian underground hard rock mines for open stope support design and is frequently used in the mine planning phase to assess the viability of stope geometries and to determine maximum permissible spans. The Method is well accepted due to its simplicity and suitability to a wide range of mining methods requiring the use of sublevels to access and extract the mining blocks. While this Method is reliable in situations where the maximum induced tangential stress creates adequate compressive stress keeping the face in a state of confinement, the Method fails to reflect the effect of low confinement caused by lower compressive stresses and instances where tensile stresses are developed. In this paper, a new Rock Stress Factor, A?, an update to the original Rock Stress Factor, A, is proposed, which will reflect the impact of low confinement or overstress regime on critical face stability. Two case studies, based on two Canadian operating gold mine shows that using the new Rock Stress Factor A? to predict the stability of stope hanging-wall and footwall gives better agreement with the CMS survey results, compared with the prediction using the original rock stress factor.

May 1, 2011

By R. Gallinger, B. Kelley

"In 1997, a group of Canadian mining companies met to review the Mine Environment Neutral Drainage (MEND) program and to consider future activities. They concluded that (1) that Canadian industry and Natural Resources Canada (NRCan) should fund a small secretariat in Ottawa to support technology transfer in Canada and, (2) that it was important for industry to continue the momentum of MEND on an international scale.The need for the International Network for Acid Prevention (INAP) was strongly endorsed by consultants, company, university, and government experts from Australia, Canada, and the United States who convened in Vancouver in February 1998. The initial focus was the development of a solid knowledge base covering the collective experience of INAP’s members to promote the dissemination of successful practices, the identification of knowledge gaps, and the formulation of effective research proposals. The sharing of information on past successes and failures alone was viewed assufficient justification for the formation of INAP.INAP was officially launched in October 1998, and is now an effective, industry-based initiative to globally coordinate research and development in the management of sulphide mine waste. Significant improvements in the management of sulphidic mine materials through knowledge sharing, research, and development of technology by INAP will reduce liability associated with acid drainage.This paper will explore the international efforts and activities of INAP."

Jan 1, 2005

By R. Gallinger

In 1997, a group of Canadian mining companies met to review the Mine Environment Neutral Drainage (MEND) program and to consider future activities. They concluded that (1) that Canadian industry and Natural Resources Canada (NRCan) should fund a small secretariat in Ottawa to support technology transfer in Canada and, (2) that it was important for industry to continue the momentum of MEND on an international scale. The need for the International Network for Acid Prevention (INAP) was strongly endorsed by consultants, company, university, and government experts from Australia, Canada, and the United States who convened in Vancouver in February 1998. The initial focus was the development of a solid knowledge base covering the collective experience of INAP?s members to promote the dissemination of successful practices, the identification of knowledge gaps, and the formulation of effective research proposals. The sharing of information on past successes and failures alone was viewed as sufficient justification for the formation of INAP. INAP was officially launched in October 1998, and is now an effective, industry-based initiative to globally coordinate research and development in the management of sulphide mine waste. Significant improvements in the management of sulphidic mine materials through knowledge sharing, research, and development of technology by INAP will reduce liability associated with acid drainage. This paper will explore the international efforts and activities of INAP

May 1, 2005