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By Paykan Safe

?? Background ?? WorleyParsons Gas Cleaning ?? PT Inco Smelter ?? Process Design Considerations ?? Furnace Control and Combustion ?? Combustion Chamber ?? Spray Chamber ?? Draft Control ?? Baghouse ?? Secondary Ventilation ?? ID Fan ?? Dust Handling Equipment ?? Project Execution ?? Heat Recovery ?? Conclusion ?? WorleyParsons Gas Cleaning ? Irving, TX ?? Formerly Gas Cleaning Technologies ?? Acquired by WorleyParsons in 2005 and now part of a global EPCM company ?? 14 years experience in off-gas system design for ferrous and non-ferrous facilities worldwide

May 1, 2008

By T. G. Paradis, C. A. Mohns

"This paper summarizes the Wren CAT (Clarifier and Accelerated Thickener) deep bed thickener operation at the EKATITM Diamond Mine in Canada’s Northwest Territories. EKATITMs’ thickener project is presented in terms of initial design considerations and present day operating practices. A circuit description summarizes process equipment, reagent systems, and typical process conditions, and details of Wren CAT operating principles are provided. Operating strategies are discussed, with emphasis on process instrumentation and control and operating challenges.INTRODUCTIONThe EKATITM diamond mine, operated by BHP Diamonds, Inc., is located in the Northwest Territories near Lac De Gras, approximately 300 km NNE of Yellowknife, NT. 9000 dry metric tonnes of diamond-bearing kimberlite ore are processed daily. Processing operations commenced in October, 1998.The EKATITM process plant flowsheet features typical steps in diamond recovery plant design. Figure 1 shows the general plant flowsheet. Size reduction and feed preparation are accomplished by crushing, scrubbing, and high pressure grinding rolls (HPGR) through closed-circuit classification with vibratory screens. Heavy medium separation (HMS) is used as the initial stage of heavy mineral concentration. Secondary concentration is accomplished in the recovery plant by attrition milling; wet, high-intensity magnetic separation (both wet and dry); and X-ray sorting.The present budget throughput rate is 9000 dry tonnes per day. This will be increased to 18,000 tonnes during the first ten years of operation. Unlike most kimberlite treatment facilities, which process material from a single ore body, EKATITM’s process plant was designed to accommodate ore from five different kimberlite pipes, each with its own treatment characteristics.All processing, except for primary crushing, is carried out in a temperature-controlled environment in the main process plant building."

Jan 1, 2000

By R. Simkus, J. K. Gowans

Polaris Operations, a Cominco Ltd. lead-zinc mine, is located on Little Cornwallis Island, Northwest Territories, at Latitude 75°23' N and Longitude 96°75' w. When the Polaris Mine went into operation in late 1981, it became the world's most northerly base metal mine.The Polaris Concentrator, housed in a unique process barge, is a basic lead-zinc concentrator where flotation is used to produce the lead and zinc concentrates.The paper describes the ""coarse lead"" flotation feature incorporated in the concentrator flowsheet and describes the start-up problems and continuing operation of this circuit.

Jan 1, 1984

By Pierre Roy, Claude Gosselin, Maryam Sadeghi, Michel Bourassa, Christian Rochefort, Claude Bazin, Gautier Mahieu, François Lavoie, Marilène Renaud, David Cataford

"Spirals are gravity concentrators used for the concentration of iron oxide minerals from ores. This paper presents the mineral size recovery curves observed for spirals operating in two Canadian iron ore processing plants. The size recovery curves are presented for rougher, cleaner and re-cleaner spirals. The partition curves observed for the spirals are significantly different than those observed for typical gravity concentration devices such as hydrocyclones or hydraulic classifiers. The size recovery curves show the complex behaviour of the minerals as they flow down a spiral and are analysed with a view toward process modelling and simulation. Initial simulation results show that gains in the iron recovery can be achieved by increasing the recovery of coarse iron oxide particles in the rougher spirals.INTRODUCTION Spiral concentrators are gravity based separation devices used for the preparation of coal, iron and different heavy minerals ores (Wills, 1992). The classification of the particles in spirals is based on the combination of gravity, centrifuge, drag, lift and Bagnold forces (Atasoy and Spottiswood, 1995; Burt, 1984; Bouchard, 2001). Several papers are dedicated to the analysis of the forces acting on the particles flowing down a spiral (Das and al., 2007; Sivamohan and Forssberg, 1985; Holland-Batt and Holtham, 1991; Holtham , 1992). Most of these papers aim at the development of a general model for the simulation of the classification of the particles for coal ore processing. Few papers deal with the operation of spirals for processing iron ores (Hyma and Meech, 1989; Srivastava, 2001; Dallaire et al., 1978) and fewer papers present results for spirals used as cleaners following a rougher stage. Since the classification in spiral classifiers is dependent on the particle size and specific gravity a partition or performance curve commonly applied to classifiers (Mai Manga et al., 2012) is used here to analyse spiral operation. Few papers were found to describe the operation of spirals in terms of partition curves (Atasoy and Spottiswood, 1995; Holland-Batt and Holtham, 1991; Richards et al., 2000). Most of the investigations presented the application of a model to simulate the position of coal particles of various sizes and specific gravities along the trough of a spiral (Kapur et al., 1996; Holland-Batt and Holtham, 1991). In addition most of the available literature on spirals deals with one stage of concentration by spirals (Dallaire et al., 1978; Das and al., 2007; Sivamohan and Forssberg, 1985) while industrial circuits usually consist of rougher and cleaner spirals."

Jan 1, 2014

By Emilio Giuseppe Sarno Severi

Mining and Petroleum Similar Industries ?Asset Intensive ?Exposed to market volatility ?Highly Risky Operations ?Scarcity of Experienced and Trained resources ?Operating in diverse countries with different cultures ?Increasing Environmental and Safety Regulations

Nov 1, 2011

By K. Honkivaara, S. Junnikkala, J. Aho, K. Föhr, P. Lampinen

"Bubble area flux has been claimed to be a major tool to dimension flotation equipment. The paper describes laboratory scale (batch and 301 continuous cell using plant feed) and small-scale (1 ,8m3) industrial experiments with coarse-grained massive sulphide ore.Samples were taken with different froth thickness and air addition rates while the bubble size was measured with an UTC capillary device. Problems of averaging the bubble size measurements and the bubble area flux measurements are also discussed.Material balances were calculated using the commercial program BILCO. The flotation rate constants were calculated for pulp and for froth assuming that we can extrapolate the flotation rate constant of the pulp phase from tests using very thin froth thicknesses.The results indicate that the bubble area flux is not alone an adequate dimensioning tool. With fine sizes there was a nearly linear relationship between the bubble area flux and rate constant for constant impeller revolutions. For coarse sizes the form of the relationship is non-linear and seems to go through a maximum value. Thus the final flotation outcome is not a simple function of bubble area flux but depends on the particle size distribution and other more traditional flotation cell dimensioning variables. The effect of the froth residence time in the total recovery of coarse particles is large, but will not be treated in this paper."

Jan 1, 2000

The major factors limiting the establishing of vegetation on the shale and sandstone wastes at Minto are high exchange acidity and low pH (shale pH 4-5, sandstone pH < 4). In the first revegetation program (1967-74), 3.8 million trees were planted without grading on 4,000 acres (red, jack and scots pine and black locust). White dutch and sweet clover, birds-foot trefoil and red top were established in selected areas, and ponds were stocked with brook trout. In the second phase of reclamation, beginning in 1979, a comprehensive plan will be initiated which will allow for forest production, wildlife development and recreational activities.

Jan 1, 1977

By David W. H. Ellis

This presentation will discuss over 2 dozen past, present and future oils sands projects in Alberta. The very early projects as well as the most recent along with the ones that never got off the ground and the ones in production are all included. For each, the following will be given (where known): owners, location, type (mining/SAGD/refinery), production, capital budget, spent to date, status. Some overall impacts will be discussed.

May 1, 2004

By T. Peters, W. C. Ferguson

"Shebandowan is about 600 miles west of Sudbury and 50 miles west of Thunderbay close to the trans Canada highway. Shebandowan Lake is about 38 miles long. The ore body is located between No. 1 and No. 2 shafts at the lower end of the lake. The economic mineralization lies between 200 and 2000 feet below. Years ago development of this ore body would probably have entailed draining the lake and using the open pit method to mine the ore.The water of Gold Creek which flows into Lake Shebandowan is representative of all local waters and is very close to rain water in purity. It is obvious that any industrial water discharged would have a measurable impact on the local water. The dissolved solids content is low and consistent with what is normally found in northern Ontario.A Koepe headframe is the only visible evidence of the mine from the lake. The Koepe headframe is esthetically pleasing and quiet in operation. The structure is of concrete to control noise. Noise from ore dumping is controlled by dumping underground to an ore pocket 400 feet below the surface. A 3600 foot conveyor belt carries the ore underground to the mill and is out of sight of the lake and the cottagers. The main objective to all our environmental efforts has been to preserve the natural beauty of the region. The mill is housed in a conventional metal-clad-siding building painted in esthetically pleasing colours. A single service building houses warehouse, dry storage and offices. The area surrounding the mill and service building is paved or grassed and drainage from this area is collected and pumped to the tailings area. Air intake silencers are installed on the compressors which are mounted at the back of the mill. Sound measurements taken on the lake indicate that noise suppression is excellent."

Jan 1, 1975

"The measurement of error in assays collected as part of a mineral exploration program or mining operation historically has been undertaken in a variety of ways. Different parameters have been used to describe the magnitude of relative error, and each of these parameters is related to the standard measure of relative error, the coefficient of variation. Calculation of the coefficient of variation can be undertaken in a variety of ways; however, only one produces unbiased estimates of measurement error: the root mean square coefficient of variation calculated from the individual coefficients of variation.Thompson and Howarth’s error analysis approach has also been used to describe measurement error. However, because this approach utilizes a regression line to describe error, it provides a substantially different measure of error than the root mean square coefficient of variation. Furthermore, because regression is used, Thompson and Howarth’s results should only be used for estimating error in individual samples, and not for describing the average error in a data set. As a result, Thompson and Howarth’s results should not be used to determine the magnitudes of component errors introduced during geochemical sampling, preparation, and analysis.Finally, the standard error on the coefficient of variation is derived, and it is shown that very poor estimates of relative error are obtained from duplicate data. As a result, geoscientists seeking to determine the average relative error in a data set should use a very large number of duplicate samples to make this estimate, particularly if the average relative error is large."

Jan 1, 2007

By P. Choquet, F. Miller

"The development and testing of a simple low-cost gauge for measurement of tension in a cable bolt grouted in a borehole are presented. Its principle is based on a resistance wire which is wound on a 70 cm length into the spiral grooves of the wire strand cable bolt. Readings are then taken by a robust automatic data logger with a several day autonomy or by a portable readout. In order to have a complete profile of tension along the cable bolt, a number of tension gauges can be installed along its length.This paper provides a description of the development and laboratory calibration of the tension gauge and addresses the two modes of loading for a cable bolt in a rock mass, namely pure tension and shearing at a joint location.In the second part of the paper, four field tests in underground and open pit mines are reported. The first test was used to substantially modify both the gauge and the readout unit principles while the other tests which are still on-going show a very satisfactory behaviour of the modified version of the tension gauge. IntroductionCable-bolting is often used as ground support in Canadian mines for a variety of applications. In underground mines, cable bolts can be installed vertically at the back of cut and fill stopes or in an inclined fashion in the walls of large open stopes. Alternatively, cable bolts at Mines Gaspe (Noranda Inc.) are used in a fan-shaped pattern from a drill drift to stabilize the inclined roof in 25 m wide open stapes. This new application oriented our research efforts toward the design of a novel instrumentation to monitor the efficiency of most commonly used 5/8-inch cable bolts."

Jan 1, 1988

By Simon D. Handelsman

?Artisanalmining ?Application of human energy (e.g. pick & shovel) directly to produce minerals ?majority no technical skills and lack adequate working tools ?Small-scale mining ?Application of modern technology for limited scale mineral production Significance of ArtisanalMining ?15 million people in artisanaland small scale gold mining ?55 developing countries ?Use of mercury damages health of 100 million people

May 1, 2006

By John Kazakoff, Andrew Mortimore

"Production at the remote Kumtor Gold Mine in Kyrgyzstan commenced on schedule in December 1996.The ore mined during the first few months of 1997 from the upper benches of the pit did not produce the results predicted by the feasibility study. Low metallurgical recoveries experienced at the time were cause for great concern.It soon became clear the recovery difficulties centred around the preg robbing nature of the ore.Procedures were developed to selectively stockpile highly carbonaceous low recovery ore types. Testing methods were developed in the mill to quante the preg robbing activity of the ore. Preg robbing masking agents were added to the process to reduce the preg robbing activity of the ore.The importance of coconut carbon activity relative to the preg robbing activity of the ore was realized. Every aspect of the performance of coconut carbon in circuit was evaluated and optimized to improve carbon activity.Mineralogical analyses were completed defining the deportment of gold in ore and process tailingsBy year end the recovery difficulties had been overcome and plant design production had been achieved. Process improvements continue through 1998."

Jan 1, 1999

By Zoë Mullard

Just as a mine has a lifecycle, employees working within the mining sector also make several transitions throughout their career, from initial recruitment to retirement from the industry. Throughout the employment lifecycle, employees bring skills and knowledge that significantly contribute to the global economy. These skills are developed through education, professional training, coaching and through hands-on experience. Despite the current economic conditions and the demand for minerals, the mining industry is facing a substantial skills shortage due to the disparity between the number of new workers entering the mining industry and a largely ?graying workforce?. Although educational programs continue to evolve to attract people with a wide range of skills, the diversity of jobs and the strains of working in remote mining operations continue to present challenges for recruitment and retention of employees. This gap also presents challenges around knowledge transfer at a corporate and mine-site level; employers will require cultural and techno-sociological approaches to ease through these transitions. At the same time, there has been an explosion of social media tools that facilitate information sharing, cross-organizational collaboration, distance learning and knowledge capture. These tools have become increasingly popular in the last few years and their applications vary widely. The mining sector has started to adopt these tools for a number of purposes, including opportunities to harness social media to enhance human resources interactions, outreach and oversight. This paper will outline several case studies that explore leading practices for how the application of new media can assist organizations and individuals as they progress through their careers. This paper will illustrate how new social media communication technologies can be used to increase employee engagement and build organizational capacity in the mining industry. The paper will also include strategies for how to implement social media to enhance human resources applications and will cover ideas for monitoring and evaluation.

Aug 1, 2013

By U. Dillon, G. Blackwell

"Geographic information systems (GIS) provide an efficient means for the recording, manipulation, revision, display and analysis of spatially referenced data. GIS are widely used at the exploration stage of mine development, and are increasingly used for reclamation planning. The ability of a GIS to perform spatial searches and query spatially referenced data make it a powerful tool for use at all stages of mine development. As the amount of data available for analysis increases, so does the power and flexibility of GIS as a planning tool.Starting from the exploration database, this paper describes how a GIS can be used for the development of mining plans based on topography, geology and mineralization information stored in a relational database. Planning decisions approaching the optimal can then be made for a wide range of parameters, including stockpile and waste dump locations, the location of potentially acid generating and neutralizing material for dump design, profitable and risk-controlled mine extraction sequencing, and haul road locations. This is made possible by the overlay and buffer analysis capabilities of a GIS which are explored and exploited to produce a continuous mine production planning program, as well as site remediation and reclamation using a successful case study. IntroductionGeographic information systems (GIS) are a relatively new tool in the mining industry. Although they have existed for a number of years, the potential of GIS for mine management and planning is only beginning to be investigated and exploited. The unique spatial capabilities of GIS make them particularly wellsuited for use in mining, where spatial information is fundamental to the processes of mineral exploration, mine development, and environmental reclamation. A number of potential applications for GIS in the mining industry have been identified, and they are widely used for exploration and reclamation. The use of a GIS as a platform for the development of mine planning routines and software remains an interesting, but as of yet unexplored, application of this technology."

Jan 1, 2003

By Michael I. Brittan, Craig M. Sams

"Economies of scale and the variable characteristics of many large ore deposits have resulted in grinding installations using very large SAG mills fitted with variable speed drives. Low-aspectratio single-stage SAG mills were introduced in South Africa to process the consistent gold bearing Witwatersrand quartzites. Elsewhere, circuits were patterned after the more conventional North American circuits with high-aspect-ratio SAG mills followed by ball mills. This paper provides information on two recent Gold Fields group installations covering both types of SAG mill in large, single-stage applications. While these operations process similar tonnages, the mills represent opposite ends of the aspect-ratio spectrum. The Tarkwa mine in Ghana employs a low-aspect 27’ x 42’ 14MW SAG mill. The St Ives mine in Australia operates a conventional 36’ x 18’ 13.4MW SAG mill.INTRODUCTIONGold Fields is one of the world’s largest gold producers with annual production of approximately 4.2 million ounces. The Gold Fields group has operations in South Africa, Ghana and Australia, along with numerous exploration sites and advanced projects in several other countries. This paper discusses new milling operations in Ghana and Australia.TarkwaThe Tarkwa Gold Mine is located in Ghana, West Africa, approximately 350 kilometers west of the capital city of Accra (Figures 1 and 2). The site conditions are tropical with an average annual rainfall of 1,930 mm and a maximum temperature of around 35°C."

Jan 1, 2006

By Chen Xia, G. Deschenes, Wan-Tai Yen

"Ammonium thiosulphate is a potential replacement for the cyanide in gold leaching. However, the high reagent consumption hinders its practical applications. In order to reduce the thiosulphate consumption, chemical additives were used. The gold leaching tests were conducted on a sulphide copper-bearing gold ore with 0.3M thiosulphate, 0.03M copper sulphate and 3M ammonium hydroxide solution at 44% solids and pH 10.2. Sulphate, sulphite, amino acid and chelating agents were initially used as additives. It was found that chelating agents (EDTA and NTA) could reduce the thiosulphate consumption from 30 kg/t to 17.8 kg/t with some increase of gold extraction. The improvement from other additives was not significant. Other approaches were also attempted to reduce thiosulphate consumption with some success. The thiosulphate consumption could be reduced to about 17 kg/t by reducing copper sulphate concentration fiom 0.03M to 0.0015M; adding 0.04M of EDTA; replacing copper sulphate with 0.001M of nickel sulphate. The increase of pulp density fkom 44% to 60% solids could reduce the thiosulphate consumption to 17 kg/t as well. Limiting the dissolved oxygen content by sparging nitrogen reduced the thiosulphate consumption further to 10 kg/t. It could be concluded that the regulations of copper and oxygen supply in the lixiviant were the keys to reduce the reagent consumption.INTRODUCTIONCyanidation, as the predominant gold leaching method, has been used in mining industry for more than a century. The low reagent requirement and the high performance are the reasons for its great success. However, cyanidation cannot deal with ores containing large amount of copper, nickel, arsenic and zinc minerals. This type of ore may consume more reagents and result in a poor gold extraction. On the other hand, the carbonaceous materials may preg-rob the gold from pregnant solution and make cyanidation a problem leaching method. Further more, the high toxicity of cyanide represents another challenge to modern gold mines. In the beginning of the year 2000, an environmental disaster caused by an accidental spill in Yugoslavia was broadcasted world-widely (Gurevitch 2000). Gold mine operators are facing higher social pressures and increasing costs on environmental protections. The usage of cyanide in mining industry has been banned in some countries and locations such as Czech Republic, Japan, Turkey, California, Colorado, Wisconsin and Montana States. Thus, a non-cyanide lixiviant is required."

Jan 1, 2002

Overview ?Oil Sands Background ?Water Use in Surface Mining ?Tailings Disposal ?Water Balance for Surface Mining ?Implications of Emerging Regulations ?Water Management Framework ?Tailings Performance Criteria (Directive 074)

May 1, 2009

By F. Mohamm

"Recent changes in regulations and scientific advances concerning selenium bioaccumulation have placed greater importance on non-biological treatment systems for selenium control. Mining wastewater contains hexavalent selenium (selenate) as the predominant aqueous species and possibly small amounts of tetravalent selenium (selenite). Non-biological removal of selenite is accomplished readily and cost effectively by ferric co-precipitation and adsorption using ferric oxyhydroxides sourced from ferric salts or iron anodes in electrocoagulation cells. Selenate on the other hand is difficult to remove. It is often incorrectly assumed that electrocoagulation is suitable for removing both selenite and selenate. Selenate removal efficiency by electrocoagulation is low and the amount of waste residue produced high. In contrast, BioteQ’s Selen-IX™ process removes selenate very efficiently and produces a much smaller amount of stable residue. The process combines selective ion exchange with electro-reduction of selenate in electrocells that physically resemble electrocoagulation cells but are designed and operated differently. This paper summarizes four years of pilot scale demonstration on a wide range of mine waters and discusses the key benefits and limitations of Selen-IX™. The pros and cons of combining ion exchange with electro-reduction in comparison to direct electro-reduction of selenate are also reviewed.INTRODUCTION Selenium in Mining and Mineral Processing Effluents Similar to sulphate and metals, selenium presence in mining and mineral processing wastewater originates from minerals contained in the mined deposits. Therefore, no organoselenium species are typically present in these kinds of waters and inorganic species including selenite (SeO32-), selenate (SeO42) and elemental selenium account for the majority, if not all, selenium present in these streams. Elemental selenium is not always present in mine water but is often contained in smelter wastewater. To comply with new environmental regulations, a successful water treatment plant must remove selenium from all these forms effectively and economically without generating by-products that are difficult to dispose of or manage. Elemental selenium can be dealt with using filtration or gravity separation in clarifiers often assisted by flocculants and/or coagulants. Mine impacted waters typically contain other forms of suspended solids which are removed from water in this way. Once the solids are removed, the selenium species that remain untreated are the dissolved forms. In mining waters this is mostly selenate with small fraction of selenite. In smelter wastewater, the majority could be selenite. It is well established that tetravalent selenium is readily removed from water by using ferric iron co-precipitation at pH > 4 (NAMC SWG, 2010). Ferric hydroxide/ferrihydrite solids act as the adsorbent for tetravalent selenium when it is in one of the ionic forms of biselenite or selenite. This treatment for tetravalent selenium is highly efficient. Therefore, tetravalent selenium removal is generally not an issue and is often easily incorporated into lime neutralization or unit operations such as electrocoagulation used for removing other metals present in mine impacted waters. Another option of dealing with tetravalent selenium is sulphide precipitation in acidic pH which produces SeS2 and can separate selenite from other metals and/or sludge produced at neutral to alkali pH."

Jan 1, 2017

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