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By N. Morrison, E. J. Rogans, A. J. Macintosh, N. Schoeman

"The design of carbon-in-pulp (CIP), and carbon-in-leach (CIL) adsorption circuits has essentially remained unchanged since the early days of the carbon process for gold recovery. For CIP circuit the pulp residence time is traditionally fixed at one hour per contactor with a carbon concentration of between 15 and 20 grams per litre, and the counter current carbon transfer rates are in the region of 15% pulp recycle. For CIL, the pulp residence time is usually three hours per contact or, with lower carbon concentrations ( 5 to 10 grams per litre).The drawbacks of using the counter current CIP/CIL adsorption circuits are discussed using modeling developed for CIP/CIL plant design. Counter current CIP/CIL, circuits are then compared with the carousel method of adsorption circuit design.The use of equipment suitable for the carousel approach is discussed which is, the AAC cylindrical and pumping (MPS) screens, the AAC pump-cell plant and launder designs.Finally, two plants at the Vaal Reefs Gold Mining and Exploration Company that use carousel adsorption circuits, namely the Vaal Reefs No. 1 Gold Plant, a CIL plant with stepped contactors, and the Vaal Reefs No. 2 Gold Plant, a CIP using a very short residence time (AAC pump-cell) are discussed."

Jan 1, 1998

By A. B. Szwilski

The paper outlines the factors taken into account for the selection of steel arch supports. The results are based on experience using the long wall system of coal mining where roadway closure can be extreme. Results of tests on scale-model steel arches and full-scale yield elements are also presented.

Jan 1, 1979

By J. Shibata, N. Murayama

"Rare earth elements are present in more than 100 minerals, of which monazite, bastnaesite and xenotime are typical. Rare earth elements have excellent chemical and physical properties for industrial use in functional materials such as phosphors, magnets, electronic components, abrasives and catalysts. China produces more than 90 % of the world’s rare earths, and Chinese trends significantly influence the demand and price of rare earths. From the viewpoint of resource securement, it is desirable to separate and recover rare earth elements from low-grade resources and wastes. Phosphate gypsum, which is a by-product of wet phosphoric acid manufacturing, contains low concentrations of rare earth elements. In this research, the separation and recovery of rare earth elements from phosphate gypsum were investigated. A series of recovery methods including washing of phosphate gypsum, leaching of the rare earth elements with sulfuric acid, adsorption and desorption of rare earth elements by using ion-exchange resin, and precipitation of rare earth oxalates were carried out. The separation of rare earth elements from Ca2+ simultaneously leached from phosphate gypsum was also investigated."

Jan 1, 2014

By William DeWit

When rivers are contaminated from industrial operations, as often occurs near repositories of spent mine tailings, decision-support tools can be critically important in evaluating the effectiveness of various engineering impact-management measures. Even where data describing river flows and quality are sparse, simple mixing-zone models can be constructed that can contribute greatly to understanding how impact-management measures can differentially affect existing river-chemistry regimes. There can be circumstances where accumulated surface waters near contaminated land can bear contaminant loadings that could be acceptable to river regimes if there were methods available to evaluate optional discharge rates and to predict post-mixing consequences on river chemistry. Nomographs can be constructed to evaluate discharge regimes that appear capable of releasing contaminated accumulated pond water without compromising water quality in a nearby river. River-mixing zone models also contribute to predicting rates of acceptable discharge and release to the receiving environment.

May 1, 2011

By Masashige Makifuchi, Hiroki Kumakura, Kota Nagai, Takahiro Kikuchi

"A large amount of platinum group metals (PGM) are used in automobile catalyst. It is important to recover the metals from wasted catalyst. Nomura and Kageyama (2013) suggested recovery process that PGM oxides were absorbed to perovskite-type oxide based on LaScO3. In their process, the PGM in wasted catalyst as absorbed to the perovskite-type oxide as PGM oxide. It has potential to each element in the process if the perovskite-type oxide is selected properly. In this study, the PGM oxide absorption properties of various perovskite-type oxides are investigated to develop a new recovery and separation process. The various perovskite-type oxide were synthesized with metallic platinum, palladium, rhodium at high temperature in air atmosphere. And the PGM contents in the perovskite-type oxide after the experiment are determined by chemical analysis. Some of them have the properties to absorb specific PGM oxide selectively. In addition, in order to increase the amount of absorption of PGM oxide and composition of the perovskite-type oxide experimental temperature was investigated. Then it is also found that doping another specific element to the perovskite-type oxide is effective to increase the amount of absorption of PGM oxide. Then a new recovery process of PGM from wasted automobile catalyst, in which PGM can be separate to each element, was designed.INTRODUCTIONA large amount of Platinum (Pt), Palladium (Pd), and Rhodium (Rh) are used in automobile catalysis (Figure 1) (Platinum, 2013). Natural supplies for these metals are limited and PGM mining can detrimental environmental impact. Therefore, the recycling of PGMs from wasted automobile catalysis is very important. The Rose process (Figure 2) was developed as a process to recover PGM from wasted automobile catalysis. In this process, the automobile catalysis is first crushed mechanically, and then extracting agent, copper (Cu), and flux are melted at high temperature. The mixture separates into a metal phase, (Cu alloy containing PGM) and slag. The PGM is enriched by oxidizing. Cu to Cu oxide. The PGM are then recovered and separated to each element in a wet process. However, it is hard to dissolve the PGM with acid because they are chemically stable and strong oxidation agent such as aqua regia is used. Moreover, to separate the PGM to each individual element, a solvent extraction process is required."

Jan 1, 2016

Caterpillar Inc The world's largest manufacturer of construction and mining equipment, diesel and natural gas engines and industrial gas turbines. Technology leader in logistics, construction, transportation, mining, forestry, energy and electric power generation.

Aug 1, 2013

By Robert B. Parsons

"One of the disadvantages of the federal government's idea of ""taxation by consultation"" is that it seems to take longer to enact new legislation. The proposed new rules for taxing automobile benefits is one example. Here is a ball which has been batted around between government and the public several times and still has not come down to earth. Fasten your seatbelts, there may be more to come. IntroductionThe draft legislation released on April 13 contains the details of the government's current proposals on car expenses and benefits. They differ significantly from the last announced position. Finance Minister Wilson has indicated that the release in draft form will provide an opportunity for the Commons Standing Committee on Finance and Economic Affairs (the Blenkarn committee) and other interested persons to comment before the legislation is introduced in Parliament. Accordingly, there may yet be revisions.Notwithstanding the prospect of further changes, the proposed rules generally come into force in 1988. While taxpayers may welcome some of these changes, particularly the increase in the tax-exempt allowance, many must be frustrated that, at this late date, the rules for the current taxation year are not yet finalized."

Jan 1, 1988

AGENDA ? Company Overview ? Industry Direction ? Technology to support maintenance ? data access, connectivity, process historian, downtime & production reporting. ? Case Studies Company Overview Corporate Offices Client Base ?16 consecutive years of growth & profitability ?#39 of Top 50 Control Companies (Worldwide) ?470 employees ?TSX: MTK Industry Direction Improved visibility into the business so they can: ? Reduce cost through better understanding of where costs are being incurred and making timely decisions. ? Optimize operations while leveraging existing assets. ? Have a single version of the ?truth? ? Deliver reliably to stakeholders on the demand for increased accountability (safety, environmental, regulatory performance etc?). ? Respond quicker to market conditions in order to out perform the competition ? Best in Class approach. Web is becoming the standard user interface.

Apr 1, 2005

By S. N. Bhatnagar, S. K. Haldar

"Mineral exploration is an expensive speculative venture and calls for optimization of sampling. Exploration is generally planned in grid pattern to be conducted in phased manner. The objective of any such campaign is to assess the quality, quantity and its reliability. The traditional estimation methods are unable to provide a means of calculating the degree of reliability. Application of mathematical models can quantify the precision of estimation and bring forth decision-making criteria at any stage.In this paper three statistical and geostatistical models, viz., Frequency, Probability, and Semi-variogram, have been employed to evaluate sequential exploration data of RampuraAgucha zinc-lead deposit. The optimization in exploration for a specific objective has been highlighted.IntroductionAny exploration campaign demands heavy resource investment starting from the collection of the first sample to the production of the first ton of ore. The best estimation would be if the entire orebody is taken out and sampled. However, this is neither possible, nor desirable. Drilling is the primary tool of geological sampling. It shares the major portion of the investment and, thereby, warrants critical analysis at every stage during the ongoing exploration projects.The exploration program should be conducted as a well planned scheme based on a sequential evaluation approach in a phased way to achieve a specific objective. It would then be possible to evaluate exploration data at the completion of each phase by employing computer-based mathematical techniques to quantify the precision of the estimate for fulfillment of objectives. The subsequent drilling program should be modified accordingly."

Jan 1, 1987

By Douglas H. Silvey

"The historical transformations in fire -resistant conveyor belt compositions in the past 20 years have been influenced by factors of material cost, changing flame and burn test requirements, material replacements, adhesion and oil resistance considerations, increased responsibility and legal liability. Specifically, this has resulted in a swing from neoprene-cotton belts to S.B.R. blends and synthetic fibre carcasses, and tighter quality control and documentation of test data.Flame dynamics are discussed and the function and performance of the multiple types of flame-resistant additives in the flame front are presented. Specific flame and burn test requirements are described. The belt manufacturers' requirements and criteria in selecting the types of flame-resistant additives are presented.The author will describe the composition of the types of flame-resistant compounds used in a practical production, the belts that are available on today's mark et and future developments in requirements that may further transform the composition of fire-resistant belts.IntroductionThe historical transformations of conveyor belt compositions in the past two decades have been based on factors common to those leading to changes in man y organic compositional products. These factors are material cost, new materials, the customer' s changing requirements, government regulation s and increased manufacturer' s liability.As a basis for understanding the product, I will provide a brief breakdown of the conveyor belt composite. Figure 1 represents a cross section of a typical belt. A skim rubber coats each fabric ply of the belt carcass and is of a different rubber composition than the outside layer of rubber which forms the cover. This outside cover layer is designed to protect the belt from environmental factors such as heat, oil and abrasion, and other factors involved in the service condition s under which the belt will operate. In the case of fire-retardant belt s, both the skim coat encapsulating the fabric plies and the outer cover must contain sufficient fire retardancy to overcome the contribution to burning of the decomosition products of the fabric."

Jan 1, 1982

By M. K. Kim

This study presents a framework for quality inspection of precast concrete components using the 3D laser scanning technique. As precast concrete-based rapid bridge construction is getting standardized, quality assessment of the precast concrete becomes critical for preventing any failures during the construction process. Moreover, as Building Information Modeling (BIM) gains popularity in the construction industry, autonomous and intelligent inspection systems are needed. Current method for quality control of precast concrete components, however, heavily relies on visual inspection and contacttype measurements, which are time and labor demanding. Also, storage and delivery systems of inspection information such as the procedures and results of quality inspection are lacking. To overcome these limitations of the current quality assessment technique for precast concrete, this study aims to develop a BIM-based framework for efficient quality inspection of precast concrete with the use of a 3D laser scanner. First, we formulate practical guidelines including detailed inspection procedure, selection of optimized scanner and scan location, inspection criteria, and data storage and delivery system. Second, to investigate the applicability of 3D laser scanning to precast concrete quality inspection based on the proposed framework, a case study inspecting quality of a lab-scale object assumed as precast concrete component is presented for detecting defects.

Aug 1, 2013

By Z. Wu, L. N. Y. Wong

The present study develops the numerical manifold method (NMM) as a tool to investigate the progressive failure in rock slopes. The entire processes of the progressive slide surface development related to crack initiation, propagation, coalescence and degradation to eventual catastrophic failure are successfully captured. To overcome the limitation of the original NMM associated with an improper removal of the interface cohesion of the discontinuities, the displacement-dependent cohesion removal method is adopted. Simple examples of failure of rock slopes containing different arrangements of discontinuities are modeled and their results are compared with those based on the popular limit equilibrium method proposed by famous pioneers Jennings and Jaeger. In cases of coplanar non-persistent discontinuities, close results are obtained despite the differences in the consideration of the stress concentrations at the crack/discontinuity tips. In cases of non-coplanar discontinuities, since the influence of the tensile strength is considered by both the Jaegers model and the NMM, the Factor of Safety (SF) values are similar despite the difference in the failure path trajectories predicted by these two models. The results also reveal that the original NMM without the displacement-dependent cohesion removal method is always more conservative due to the improper removal of the interface cohesion. The displacementdependent cohesion method can to some extent alleviate such a limitation.

Jan 1, 2015

By M. R. Babcock

"The Rabbit Lake story began in the late sixties and will continue well into the twenty-first century. It is a story of success, of multiple ore body discoveries, of unique systems, and new methods made possible through innovative and state-of-the-art design. Two quite different geological systems host the five ore bodies mined, or slated to be mined. These two systems have yielded two distinct ore types, each with characteristic mineralogical properties and each requiring its own specific mill circuit.Emphasis on communications and our unique systems have led to a satisfactory and fulfilling work environment resulting in the historically low employee turnover which has contributed to the operation success.A comprehensive environmental study after twelve years of operation has given the Rabbit Lake Operation a completely clean bill of health. INTRODUCTIONRabbit Lake can be described as Saskatchewan's first highgrade uranium mining operation, which set the stage for the province's current role as the leader in uranium mining throughout the western world. The importance of the Rabbit Lake operations - past, present and future.LocationThe Rabbit Lake operation is located in northeastern Saskatchewan (Fig. 1)- 805 km north of Saskatoon, Saskatchewan, and 814 km northeast of Edmonton, Alberta. OwnershipGulf Minerals Canada Limited discovered the Rabbit Lake deposit in 1968. Mining operations began in 1975and were operated by Gulf until purchased by Eldorado Nuclear Limited in 1982. In 1988, Eldorado merged with Saskatchewan Mining Development Corporation (SMDC) to form Cameco-A Canadian Mining &. Energy Corporation. The new corporation is one of the world 's largest uranium companies.Cameco's $1.5 billion in assets include the Rabbit Lake uranium mine (Cameco 100010); the Key Lake uranium mine (Cameco 66.67%; Uranerz Exploration and Mining Limited 33.33%); the Cluff Lake uranium mine (Cameco 20%; Amok Ltd. 80%); the Fuel Services Division at Blind River and Port Hope, Ontario (Cameco 100%); and a 100%); and a 48.75% interest in the Cigar Lake uranium deposit which is now at the test mining stage (Cogema Canada Ltd . 32.625% ; Idemitsu Uranium Exploration Canada Limited 12.875%; Corono Grande 3.75%; Korea Electric Power Corporation 2%). In addition, Cameco is involved in a number of base and precious metal explor ation projects."

Jan 1, 1989

By J. Robitaille, P. Cousin

"Agnico-Eagle Mines Ltd, Laronde Division, is a gold operation processing ore containing copper and zinc. Copper is recovered as a concentrate prior to gold cyanidation.Copper concentrate grade was improved with the implementation of an on-stream analyzer. Further improvements to the copper concentrate grade could be achieved throughefficient zinc depression.High cyanide cost linked to the copper content in the flotation circuit tails, prompted some modifications to the flotation circuit. Economics and environmental issues were considered. A Maxwell cell was retrofitted with an Outokumpu HG cell mechanism stabilizing it's operation. Secondly a flotation column was added to increase circuit capacity.This paper will address flotation circuit operation difficulties, successes and results achieved before and after modifications.RESUMELes Mines Agnico-Eagle division Laronde sont considéré comme étant un producteur d'or. Le minerai révèle toutefois des teneurs appréciables en cuivre et zinc. Un circuit de traitement combinant des étapes de flottation du cuivre et de cyanuration de l'or a été adopte. Le rejet de la flottation est lixivie pour son contenu en or.La teneur moyenne en cuivre du concentre final fut augmentée suite a l'implantation d'un système d'analyse en continu. Une séparation plus efficace de la sphalérite se devra d'être obtenue afin d'améliorer davantage la qualité du concentre produit.Le contenu en cuivre au rejet du circuit de flottation influence directement la consommation en cyanure. Pour cette raison, certaines modifications à la flottation sont devenues nécessaires. Des facteurs d'ordre économique et environnemental ont été considérées. Une cellule existante fut transformée en cellule HG d'Outokumpu, stabilisant son opération, et une colonne de flottation fut ajoutée au circuit afin d'accroitre sa capacité.Le présent document se veut une rétrospective des problèmes d'opération vécus, des solutions apportées ainsi que des résultats obtenus et de leurs implications suite aux améliorationseffectuees."

Jan 1, 1995

Overview of Presentation ?About MiHR ?Human Resources Challenges in the Minerals and Metals Industry ?Getting the Facts -Sector Study Project ?Key Findings ?Recommendations ?Conclusions ?MiHR?srole

May 1, 2006

By Ö Yilmaz

In this study, the behaviour of rock mass subjected to blasting load is investigated using three dimensional finite difference numerical modelling. In the analyses, Mohr-Coulomb failure criterion has been used for the characterisation of the rock mass strength. Stresses acting on the borehole boundary have been simulated by an exponential function which reaches its maximum within a short time and then falls to zero value in a considerable time period. The strain rate effect on the mechanical properties of rock material has also been taken into account in the analyses. Four different explosive-rock mass combinations have been studied to investigate blast induced damage zone. It has been observed that proposed equation for the dynamic compressive strength of rock material fits very well to general suggestions. Results have shown that blast damage analysis model recommended with this study is successful.

Aug 1, 2013

By F. Habashi

"Extractive metallurgy was divided into the three sectors pyro-, hydro-, and electrometallurgy in 1959 when Professor Joseph Newton at the Idaho School of Mines in Moscow mentioned this in his book Extractive Metallurgy. Pioneer hydrometallurgists who built this discipline can be traced to the alchemists in the ninth century. It is now a mature subject of great importance in which pressure plays a vital role. Short biographies of some hydrometallurgists and the processes they invented are briefly outlined.INTRODUCTIONHydrometallurgy is the use of aqueous solutions to recover metals from ores. It is a relatively new discipline when compared with pyrometallurgy the use of fire to melt ores and recover metals which was practiced in ancient times. Hydrometallurgy can be traced to the time of alchemists whose concern was the transmutation of base metals into gold. Although alchemists did not succeed in their venture yet they described many reagents that are useful today. For example, they prepared sulfuric acid by distillation of iron vitriol, muriatic acid by distillation of sulfuric acid with salt, and nitric acid by reaction of sulfuric acid by reaction of sulfuric acid with salpeter. Jabir Ibn Hayyan the Muslim alchemist who lived in the ninth century (Figure 1) described aqua regia a mixture of nitric and hydrochloric acid that can dissolve gold although either acid has no action on gold. THE MIDDLE AGESIn the Middle Ages, it was reported that copper was recovered at Rio Tinto in Spain by allowing copper-containing pyrite to be exposed in piles to the action of air and rain. Copper sulfate solution obtained was treated with pieces of iron to precipitate metallic copper—a process that was called cementation. Georgius Agricola (1494–1555) (Figure 2) a medical doctor in Saxony who used to visit mines and smelters to examine miners and metal workers, described in his book De Re Metallica the parting of gold, i.e., separating of silver from gold by acids."

Jan 1, 2016

By W. M. Moon, Hugh G. Miller, C. -S. So

"Digital image processing and enhancement techniques have been applied to airborne gamma ray spectrometry data from Sudbury, Ontario. These results have been correlated and compared with the available geological maps to evaluate their usefulness for identifying lithological units. Digital processing allows the correlation of various data sets, and different combinations of images can be tested and viewed as a composite image. Composite images with pseudocolours provide an opportunity to analyze and correlate information that is not otherwise apparent in individual images. Principal component analysis has been applied to the gamma ray spectrometry data to evaluate their efficacy and relative information contents of the measured and computed data. The results of this study indicate that the combined radioelements image (obtained by combining the radioelement image and the ratio images) is effective for defining areas of relative concentration of a specific element in near surface materials. Furthermore, the composite radioelements image (produced by combining three separate radioelement images) and composite principal components image reflect large-scale lithological variations. IntroductionThe Sudbury area is a unique geological structure located in the southern Canadian Shield (Fig. 1). Because the area hosts economically significant nickel-copper deposits (Pye et al., 1984), it has been surveyed in great detail by geological and geophysical methods. In order to obtain meaningful geological infonnation about the Sudbury area, several studies have been carried out with the application of innovative mathematical techniques for geophysical modelling, and attempts have been made to integrate the multisensor geophysical data available for the area (e.g. Gupta et aI., 1984; Moon et al., 1988; Singh et al., 1993). The main objective of this paper is to apply digital image processing and enhancement techniques to airborne ganuna ray spectrometry data in order to determine their usefulness for regional geological mapping."

Jan 1, 1994

"Cambior now holds a 49% interest in the Valdez Creek Placer, having acquired American Barrick's 23.125% interest in May 1990. At the same time, the company assumed the management of the operation and received environmental permits to divert the river. Plans are underway to divert the Valdez River in order to continue mining the deposit upstream, and to construct a new, higher capacity wash plant (by 60%) closer to the operations. Mining operations, which were suspended in October 1989 pending higher gold prices, resumed in August 1990. The mine is expected to produce 10000 ounces of gold in 1990and more than 80 000 ounces in 1991.IntroductionThe Valdez Creek Placer is located in the Valdez Creek mining district of Alaska on the western flank of the Clearwater mountain range, about 150 miles northeast of Anchorage by air (Fig. I) . The mine is accessible by air or by road.The mine is situated at an elevation of about 3000 ft and is isolated from towns and villages. Consequently, the mine site contains the facilities necessary to house and feed 135 people at any given time. The Valdez Creek Placer has 159 employees, including 130hourly and 29 salaried employees. The hourly employees are divided into three rotating teams. The daily schedule consists of two shifts of 12 hours, and each team works 14 days followed by seven days off, resulting in a weekly rotation of teams.The salaried employees work normal hours for ten consecutive days followed by four days off. A weekly rotation ensures continuity of services and management.Gold was first discovered at Valdez Creek in 1903, when a team of four men led by Peter Monahan left the village of Valdez to explore the area up the Susitna River, to the east of Mount McKinley. They discovered gold at the mouth of a creek that they immediately named Valdez Creek, in honour of their native town. In 1904, they discovered the Tammany Channel to the right of Valdez Creek. This was the beginning of a long period of mining in the area which continued until the beginning of World War II .In 1980, the Denali Mining Co. was formed. Geophysical work and drilling carried out through 1980 and 1981 led to the discovery of Channel A, a second channel which is older than the Tammany Channel. In 1983, Denali Mining optioned its claims to Camindex to explore, develop and mine the Valdez Creek property. A joint venture agreement was signed among Camindex, Talcorp, BCP Alaska (Barrick), Sum Resources (Cambior), Norfran and WGM to form Valdez Creek Mining Co., Inc., and production began in 1984. Valdez Creek Mining Co., Inc. (VCMC) was subsequently restructured and in 1989 was held by the following three companies: Camindex Mines Ltd. - 51070; Cambior Inc. - 25.875%; and American Barrick - 23.125%.VCMC is managed by a committee of the partners. Decisions made by the committee are subject to a 70% majority vote. Cambior receives its share of production in kind, and contributes in the same proportion to the expenses of the joint venture (VCMC)."

Jan 1, 1990

By Q. Han, W. Dai

Al-Ti-B type master alloys have been widely used in the grain refinement of aluminum since 1940s. The introduction of Al3Ti and TiB2(AlB2) particles reduces the grain sizes down to about 200 micrometer level and makes cold work possible. However, the mechanism for the grain refinement is still not clear, though it is believed that TiB2 in the presence of Al3Ti nucleate a-Al grains in solidification. This paper presents our finding on the formation of (Ti,Al)B2 solid solution, which leads to a proposed theory on grain refinement by Al-Ti-B type master alloys that upon addition into aluminum melt stable TiB2 particles react with aluminum slowly and release titanium into the melt. The titanium thus released in combination with titanium in the melt through dissolution of Al3Ti maintains a transient titanium-rich layer on the surface of (Ti,Al)B2. This layer offers a low crystal mismatch with a- Al and promotes the nucleation of aluminum grains.

Jan 1, 2014