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By Bill Parnell

"Friction winders and double drum winders have been used in the vertical shaft mining industry for over 100 years. In that time, there have been many changes made in the electronic and mechanical fields of hoisting, but few changes made in the manufacturing and performance of steel wire rope, until recently.In the past ten years, with the advent of high polymer thermoplastics, the industry has seen some major advancements in steel wire rope. By incorporating a polymer with steel, improvement of rope life and reduction of costly maintenance downtime has been accomplished.IntroductionThe Williams Mine is Canada's largest gold producer with an annual production of some 500 000 ounces of gold from 2.2 million tonnes of ore. The Williams Mine is situated in the Hemlo area of northwestern Ontario, approximately 40 Ian east of the town of Marathon. It is operated by the Williams Operating Corporation which is owned equally by Teck Corporation and Homestake Canada Inc. It is one of three adjacent properties forming the Hemlo gold camp."

Jan 1, 1995

By K Hooper

Over the past 20 to 30 years statistics as a science has grown in significance. Not a day passes without reference to the latest statistics by the print, audio and audio-visual media. The Northern Territory Government has been part of this growth and like other public and private sector organisations collects a broad range of statistics. The Northern Territory Department of Mines and Energy participates in the government's statistics collection process. Statistics collected and published by the Department of Mines and Energy include geoscientific; mining and exploration tenure; environmental (e.g. mine site waste water management); production of minerals, oil and gas; mining sector employment; and occupational health and safety. The importance of statistics collection to the Northern Territory Government is discussed in the paper.

Jan 1, 1994

By M. Leroux, P. Lacombe, S. R. Rao, J. Y. Kim, J. A. Finch, G. Labonté, N. Macminn, M. Ounpuu

"Laboratory investigations on two complex ores, the A1 zone ore from Les Mines Selbaie and the Lyon Lake ore from Mattabi Mines Ltd. (Division of Noranda Minerals), have been carried out to determine some of the main variables in collectorless flotation. In particular, the effect of pulp potential (controlled by gas composition), conditioning time, pH and grinding media have been studied.Chalcopyrite showed the greatest response to collectorless flotation among the four major sulphide minerals present, followed by galena. Flotation of sphalerite was variable from minimal to important depending on the mineralogy and the pre-treatment performed. Appreciable silver recovery was achieved collectorlessly for the Lyon Lake ore while it could not be achieved for the A1 zone ore of Les Mines Selbaie. It appears that the difference between the two ores is related to silver's predominance as tetrahydrite in the Lyon Lake ore while it is as argentite and native silver in the A1 zone ore.The response of the ores to collectorless flotation is strongly dependent on the pulp potential, Ep, and pH. Using different gas compositions and different conditioning times it was found that collectorless flotation occurs when Ep is +195 to +295 mv (vs SHE). The actual on-set potential for collectorless flotation is dependent on the ore. A too high potential or prolonged oxidation leads to a decrease in selectivity. Some other factors were examined, notably the effect of pH and the type of grinding media on the selectivity achieved in the laboratory.Preliminary results from a plant trial at Mattabi Mines Ltd. confirmed that collectorless flotation occurs and that it is preferential for chalcopyrite and to a lesser extent galena. Collectorless flotation was not attempted at Les Mines Selbaie. However, examination of the distribution of collector between the different addition points in the copper circuit suggests that it may be present."

Jan 1, 1990

By John Brown

Let’s talk about things that you, the driIl boss, the pit boss and the driller can do to eliminate the trend in drilling related accidents that have come to plague our industry in recent years. My paper will focus on reaI issues, problems and solutions that will affect our everyday outlook and attitudes about our jobs and lives. There are some real hard facts we must address if we are going to reverse this terrible killing trend.

Jan 1, 2000

By H. O. Hofman

The mining and metallurgical laboratory, as we understand the term in this country, is a place .in which mechanical and chemical working-tests are made on ores, fuels and furnacematerials. It is of quite recent origin. The first laboratory of this kind to be used in connection with teaching was put into operation in 1871 at the Massachusetts Institute of Techilo1ogy. † The idea had already existed in the mind of President W. B. Rogers when he wrote, in 1864, his pamphlet 'on " The Scope and Plan of the School of Industrial Science of the Massachusetts Institute of Technology;" but several years elapsed, and an extended visit to the mines and mills of Colorado, Utah, Nevada and California was required before this idea could take a form adapted to the purposes of original research as well as of instruction. The laboratory was given from the first into the charge of Prof. R. H. Richards, who, by improving its methods and enlarging its scope, has brought it to the position which it occupies to-day as the leading representative of its class. Private laboratories for making tests upon ores had previously existed here and there, especially on the Pacific coast, for silver and gold ores; but in the educational field the

Jan 1, 1896

By Thomas O. Glover

Cameroon continued to enjoy sustained economic growth that began with its independence in 1960. Growth in the gross domestic product (GDP) averaged 2.8% per year during the 1960's and the first half of the 1970's. Starting in 1976 and for the succeeding 10 years, the GDP accelerated rapidly owing to the coming on-stream of Cameroon's small but domestically significant offshore oil industry. In 1985, the GDP grew by 7.8%, but in 1986, it was only up 5.5%. The country's sustained economic growth in dollar terms of gross national product (GNP) per capita reached $1,075 in 1986. The ranking in GNP per capita by the International Monetary Fund put Cameroon in the middle-income category for developing countries. The sustained economic growth rate up to 1986 was due to the injection of income from oil into the economy, but crude oil price reductions in 1986 brought a slowdown. In 1986, crude oil production grew to 200,000 barrels per day, an increase of 8.2% from that of 1985. Most of the oil came from the Société Nationale Elf Aquitaine (SNEA) wells in the multifield Rio del Rey complex. Additional output came from the Moudi Field operated by Compagnie Française des Pétroles S.A. Proven oil reserves in Cameroon were 540 million barrels. At 1986 production rates, and in the absence of further discoveries, Cameroon will have exhausted its recoverable oil reserves by the year 1995. Owing to worldwide crude price reductions, the country's oil income fell 60% between 1985 and 1986, from $1.82 billion2 to $0.72 billion. Cameroon's refinery operator commenced operating the Sonara refinery in 1981 at Point Limboh. Sonara's capacity of 43,000 barrels per day was small by most standards. In 1986, natural gas reserves, estimated at 100 billion cubic meters, were not produced commercially because there were no domestic users. Proposals for a multibillion-dollar liquefied natural gas plant at Kribi had been submitted; however, work on the plant had not commenced.

Jan 1, 1988

The introduction of computer technology to the mining industry has produced many benefits for the mining engineer. The most significant is the dramatic increase in productivity realized by the individual user. This is important during times of competitive market conditions. Software for the minerals and energy industries has evolved substantially over the past decade. But even today it remains difficult to find a system that features the flexibility and integration capabilities to effectively (and cost-effectively) handle the needs of professionals in each phase of the mining industry - from exploration to reclamation. Several national software developers are now addressing this challenge. One Denver-based company, MINEsoft Ltd., offers a software package that is currently being used in each phase of the mining industry. The basic technology used in MINEsoft's database management system was developed in the 1960s. But during these early years of the computer industry, most of the technology was available only on mainframe computers, and then only as separate entities. MINEsoft's system unifies these various systems in one package that can be used on most computers manufactured today. Database Management System TECHBASE is a flexible, integrated database management system designed specifically for technical applications. The system features a database manager with no practical limit to the amount of data it can store, retrieve, and manipulate, according to the company. TECHBASE in¬cludes Applications Packages (TAPs) designed to meet the needs of professionals in a host of industries. Clients use the TECH BASE system to prepare many reports, including important EPA information. The package reduces data to a manageable level and enables users to increase productivity with a smaller staff. Mining engineers no longer need to do things by hand. What used to be a day's work can be accomplished in an hour or two. Exploration "Using the TECHBASE system to generate maps has probably saved us the expense of three or four draftsmen," says Ralph Fitch, regional manager and senior staff geologist with Chevron Resources in Portland, ME. "The system has great flexibility. You can treat it much like a spreadsheet. If you are halfway through with a particular project, the system allows you to add fields and calculations with ease but without starting over." Fitch uses TECHBASE for the "straightforward" plotting of results and generation of geochemical and geophysical profiles. "In exploration," he says, "these are the two key elements ... the generation of maps and data profiles. The system allows you to plot as many elements and variables in these areas that you like." Other aspects are important, too, says Fitch, including drill hole sections. "We use all the basic capabilities the system provides in the complete package," he explains. "When shopping for a system, TECHBASE was clearly dedicated to exploration in the

Jan 9, 1987

By Brad Marchant, Rick Lawrence, David Kratochvil

"BioteQ has successfully developed commercial operations for ARD treatment and selective metal recovery using the patented BioSulphide and Thiopaq® biological reduction technologies. The BioSulphide-Thiopaq process was developed to provide biogenic sulphide for the selective recovery of high purity metal concentrates from acidic wastewater, which are sold to recover capital costs and off-set water treatment costs. The BioSulphide-Thiopaq process can be used on a stand-alone basis or in conjunction with a lime circuit. Process advantages include: selective recovery of metals, very low metal concentrations in effluent, reduced waste sludge liability, reduced lime treatment costs and, in some cases, profitable sale of metal concentrates. Two case studies are presented to illustrate operations focused on metal recovery at the Caribou Mine, New Brunswick, Canada, and at Phelps Dodge, Arizona. A third case study is presented to highlight environmental control as well as metal recovery for treatment of ARD at the Raglan Mine in Northern Quebec. Process flowsheets, capital and operating costs are presented for the three case studies.INTRODUCTIONProtection of water quality has become one of the most important environmental challenges facing the mining industry. Although new mining projects can be designed to minimize impacts to the environment, many existing and abandoned mining operations have water quality problems. The principal cause of water contamination is acid rock drainage (ARD), which is generated when residual sulphide minerals in waste rock, tailings and other mine components and products are exposed to air and water. These reactions can produce acidity and elevated concentrations of metals in drainage and seepage that can adversely affect surface and groundwater resources. To meet regulatory criteria for water quality in the receiving environment, many mine operators must consider treatment of mine water and other effluents prior to discharge."

Jan 1, 2003

The National Institute for Occupational Safety and Health (NIOSH) has continued study of the Personal Dust Monitor (PDM) developed by Rupprecht & Patashnick Co. Inc. through a CDC contract and currently being commercialized by Thermo Fisher Scientific. This report examines the effect of oversize particles, cyclone inversion, and cleaning procedures. Clean and exposed filters were examined using light microscopy and particulates counted before and after various instrument manipulations. The data presented show that the dry cleaning procedures do not cause significant (greater than limit of detection) sample contamination by respirable or oversize particulates and that the cyclone is resistant to particulate carry over during inversion.

Jan 1, 2009

By H. Ewaschuk

"INTRODUCTIONRio Algom's involvement with the Enviro-Clear thickener began in May 1975, when tests on a laboratory waif were carried out by our Research and Development group. Commencing in June, further tests were carried out using a 3 foot diameter pilot unit. By December, a 30 foot full-scale thickener had been installed. In the near future, 3 more Enviro-Clear thickeners will be commissioned. With in the space of a year, almost $2.5 million had been committed to liquid/ solid separation facilities using the Enviro-Clear thickener. This paper briefly traces the extent and development of this commitment.BRIEF HISTORY OF QUIRKEQuirke Mine started operating in September 1956 at a rated capacity of 3,000 TOD. Because of market conditions, Quirke was shut down in December 1960. The facilities were re-opened at an increased capacity of 4,000 TPD in July 1968, by which time the demand for uranium had returned. Also, a second shaft was sunk, and by 1970, all of the ore treated in the concentrator was coming from the new Quirke II mine. The Quirke I stopes were allowed to fill with natural seepage. As well, acidic barren solution from the concentrator was pumped underground.With increasing demand for uranium, the capacity of Quirke will be further expanded to 7,000 TPD by 1978. Studies of how this expansion could best he carried out led to the consideration of a fairly new piece of equipment, the Enviro-Clear thickener, for certain operations in the concentrator. These operations are as follows:"

Jan 1, 1977

By C Ferron, R Massimi

There is approximately 240 000 tonnes of arsenic trioxide dust stored in underground chambers at the Giant Mine in Yellowknife, Northwest Territories, Canada. To minimise the amount of arsenic released to the environment, a number of closure alternatives are being considered. One alternative is to mine the dust, encapsulate it and dispose the mixture into a secured landfill. The potential leaching behaviour of the encapsulated dust was examined in a laboratory programme. Cylinders of arsenic trioxide dust mixed with cement/aggregate and bitumen were prepared. The dust content varied between zero per cent and 60 per cent of dry weight charge. The cement cylinders were tested for strength, leaching and freeze/thaw durability. The bitumen cylinders were tested for leaching only. The results show that increasing dust content in the cement cylinders negatively impacts the strength and the freeze/thaw durability of the samples. A contributing factor is likely the high water to cement ratio in the samples. Leaching tests show that arsenic release from cement cylinders increase with increasing dust content. Arsenic concentrations in leachates do reach a plateau at a certain point in time. Arsenic release from bitumen cylinders was significantly lower compared to cement cylinders. Arsenic concentrations eventually were less than 0.05 mg/L in samples containing up to 25 per cent arsenic trioxide dust. Arsenic leaching rates were found to decrease by an order of magnitude over the course of three months.

Jan 1, 2003

By D. C. Rance

"The Quintette Coal Limited property is located in the north east coal area of British Columbia. A basic agreement with the Japanese steel industry was ex ecuted on January 27, 1981 for the sale of 69.5 million tonnes of Quintette metallurgical coal over a 14.5-year period. This contract period can be extended by Jive years by mutual agree ment. Sale agreements have also been signed for the sale of 19.4 million tonnes of oxidized coal over a 15-year period. Work started on site development in the late summer of 1981, and at present, two of the four eventual pits-the McConkey and Frame-are under development. The pits are currently in a pres/ripping phase. These pits are notable for the stripping volumes that have to be removed from relatively small pit areas. in order to provide for the required detailed rapid short-range planning of these pits, engineering will be computerized, as will the truck dispatch system. The mining area lies 21.1 km from the plant site by road and the transport of raw coal LO the plant is by means of a highspeed conveyor system which has a total length of 13.4 km with a vertical drop of 740 m. The surface plant facility was designed on a modularized basis to facilitate maintenance, and is designed to enable the use ofgravity flow ofraw coal and heavy media in the plant to minimize the use of pumps. The construction of the plant and mine site facilities is on-going, and the first coal production is scheduled for early December 1983. Introduction Quintette Coal Limited is a Canadian company incorporated in the province of British Columbia in 1971. Denison Mines Limited is the manager of Quintette's activities. Equity in Quintette Coal Limited is held by several shareholders, with interests as follows: Denison Mines 'Limited, 500Jo; Charbonnages de France International S.A., 120Jo; and Japanese interest, 38%. The project will develop almost 120 million tonnes of coal for marketing during its first 20 years of production. All of the planned production tonnage has been committed to Japanese markets. Most of the coal will be metallurgical grade, and the remainder will be a high-quality thermal coal. The Mcconkey and Frame pits, which will initially provide the mine's production, will commence production in early December 1983 and will, in 1985, reach the full annual production of 5 million tonnes clean metallurgical coal and 1,380,000 tonnes of clean thermal coal."

Jan 1, 1985

By W. G. Pariseau

This contribution focuses on the role of stress analysis for mine planning and the selection of suitable computer programs for the task with special emphasis on coal mine pillars. In this regard, barrier pillars that defend a set of five main entries at the Crandall Canyon coal mine in central Utah were formed during extensive longwall mining north and south of these main entries. Numerical analysis for ground control guided the mine planning and permitting. Retreat mining of pillars led to disastrous events August 6 and 16, 2007, with the loss of nine lives. A most difficult lesson taught by the Crandall Canyon tragedy is the need for education in the selection and use of computer programs for pillar design. Much of this contribution is taken from a report prepared for the Mine Safety and Health Administration (Gates, et al, 2008). Details appear in Appendix Q of the report (Pariseau, 2008). The Crandall Canyon mine is about 16 miles west of Huntington, Utah, in the Wasatch Plateau coal field. Geology of the Wasatch Plateau is described by Doelling (1972) as gently dipping Cretaceous sandstones, mudstones, coal seams, and shales. Joint systems are present in strata above and below coal seams where cleat systems are present as described by Hucka (1991). Several major fault systems transect the field and form grabens with 450- 760 m of drop. One such structure is Joes Valley fault that crosses the Crandall Canyon mine. Mines in the Wasatch Plateau are generally developed from outcrops in steep canyon walls. Overburden increases rapidly as mining progresses into the plateau; mining depth varies with topography between 450 and 600 m in the region of interest. A stratigraphic column derived from a borehole into the mine is shown in Figure 1. There are 11 layers in the column.

Jan 1, 2011

By Danny A. Riley, James R. Sanger, Hani S. Matloub, Michael Agresti, David Rowe, Lin-Ling Zhang, Yuhui Yan, Paula Galaviz, Judith Marchant-Hanson, Ji-Geng Yan

Until now there has been controversy about which tests should be performed to diagnose early Hand-Arm Vibration Syndrome (HAVS). Initial screening questions, especially about tingling and numbness, routinely given to patients prior to examinations proved to be a very important tool in the diagnostic process1, 4. However, standardized tests that are simple, quick, valid and reliable are needed to support a diagnosis of HAVS. Purpose: To find the most valid and reliable tests to diagnose HAVS. Material and Methods Five major tests were performed on Group I and Group II. Group I: Control group of 12 volunteers including students, nurses, secretaries and physicians with no history of using vibrating tools (age 20 to 50y, mean age 38.5y; 5male, 5 female.) Group II: 12 workers (age 17 to 65y, mean age 39y; 9 male, 3 female) were sent by a local trade union with a history of using vibrating power tools on their jobs for varying amounts of time (mean 12.2y, from 0.5 to 35y.) Pre-enrollment survey showed that each had more than 4 complaints commonly associated with use of vibrating tools (including numbness, tingling, weakness, pain, finger color or nail changes, temperature change, and difficulty moving.) 1. Sensory nerve conductive tests: Amplitude and nerve conductive velocity (NCV) were evaluated. 2. Cold Stress-Temperature recovery time tests were done on the index finger of the dominant hand following these steps: Confirm water bath is within 4-5º C. Place the finger temperature probe on pad of the index finger of the dominant hand. Record temperature every 15 seconds. Place subject’s hand in the cold- water bath for exactly five minutes. Record temperature every 15 seconds for ten minutes. 3. Blood test: Venous blood was taken by a 21-gauge needle with the yellow collection tube adapter. S-ICAM, Sera Thrombomodulin, Norepinephrine levels were evaluated by Henderson Research Centre, Canada. 4. Finger Sensory Evaluation: Semmes-Weinstein monofilament test and 2-point discrimination tests were performed on bilateral fingers. 5. Digital blood pressure test: blood pressure was measured in bilateral index fingers. Results 1. Median nerve sensory conductive amplitude from palm to wrist : GI: mean 96 ± 31µm; GII: mean 43± 30µm; for dominant hands. GI vs GII: P<0.001

Jan 6, 2006

By Joseph Moses Botbol

In passing the judgments essential to his trade, the geologist may be assisted by two new methods. These will enable him to (1) arrange the minerals of a selected group of base metal mining districts in the order of their typicalities and (2) compute the degree of mineralogic association between the model so derived and a district external to the model. It must be remembered, of course, that the methods discussed in this article are no more powerful than the structure of the model used and the data available. The geologist who employs these techniques must still exercise his expertise

Jan 1, 1970

By Y. F. Bulgakov, Y. V. Melnikova, V. S. Zakharov

A new technology of atmosphere in inertization of fire section with the help of gazeous nitrogen is presented in the report. This technology is based on membrane air subdivision into two streams, concentrated with nitrogen (up to 99%) and with oxygen correspondently with subsequent giving them into the place of fire. This technology belongs to environmentally friendly ones and it has a great number of technical, mobile and economic advantages comparing with the rest of well-known methods of fire extinguishing. This technology application in Ukrainian coal mines allowed to reduce the member of isolated places of fire at the expense of their extinguishing efficiency.

Jan 1, 2003

OneSteel and BlueScope Steel have been working with the CSIRO to develop sustainable carbon fuels and reductants which are suitable for use in the iron and steel industry. One of the initial focuses of this work has been a process called steel recarburisation which is the addition of carbon to liquid steel to produce particular steel grades. This paper reports on the preliminary work and the recent full scale recarburisation plant trials conducted at the OneSteel Sydney Steel Mill. &nbsp; Preliminary experimental work involved kilogram scale recarburisation of liquid steel with a range of commercial and prepared charcoal products. This work showed that charcoal dissolves into liquid steel very quickly and that carbon recovery to steel was inversely related to the charcoal volatile content. Initial larger scale work focused on the collection of wood, and preparation of low volatile charcoal which is required for steel recarburisation. Approximately three tonnes of charcoal was prepared at the Corrimal coke ovens of the Illawarra Coke Company. This charcoal was dried, crushed, sized and packaged in a form suitable for addition to 80 tonne liquid steel ladles. &nbsp; The recarburisation trial was conducted over 30 ladle heats during June 2009. The charcoal was manually added to the liquid steel in 5 kg bags using normal plant practice. Conventional commercial recarburiser was also added to the liquid steel in alternate ladle heats. The performance of the charcoal was compared with the conventional recarburiser based on the carbon recovery to steel, hydrogen pick-up by steel and the rate of carbon dissolution into steel. &nbsp; An analysis of the trial results showed that the charcoal performed at least as well as commercial recarburiser in carbon recovery and rate of dissolution but may have resulted in a slightly higher hydrogen content of steel. This is probably due to the higher moisture content of charcoal. The main challenges in the future include: increasing the charcoal density to improve transport and handling economics, securing a sustainable supply of biomass for the steel industry and developing a charcoal production industry so materials of suitable quality for both production and trials on other applications can be conducted.

Jun 1, 2010

In 1987 Wyoming became the largest coal producing state in the country. The state is known for its extensive coal resources and extremely thick coal seams. Wyoming&apos;s coal reserves total about 69.3 billion tons, or 14.2 percent of the U.S. coal reserve. Coal seams range generally from 10 to 80 feet in thickness, although one seam is 220 feet thick. The coal-bearing areas of Wyoming underlie approximately 41 percent of the state&apos;s total land area. Wyoming&apos;s coal ranges from lignite to high volatile bituminous. Most of the coal produced is subbituminous from the Powder River coal region near Gillette. The presence of coal in Wyoming was discovered before 1834 on the Belle Fourche River. The state&apos;s first mine opened in Carbon County in 1865, and with the completion of the trans- continental railroad, the demand for coal increased. Currently approximately 80 percent of Wyoming&apos;s coal production is shipped out-of-state to meet the growing demand for low- sulfur coal to fuel electric generating plants. Wyoming received conditional regulatory approval November 26, 1980. Its Abandoned Mine Land Program was approved February 14, 1983.

Jan 1, 1992

By Herty, C. H.

Three distinct processes take place during the conversion of iron ore to steel. First: the raw ore is reduced to metallic iron in the blast furnace and during this reduction certain constituents are dissolved in the iron, either through the solution of a solid into a liquid phase, as in the case of carbon, or by reduction of an oxide existing in the slag to the metallic element of that oxide, with subsequent solution of the metallic element in the iron. Thus by the process of solution and reduction, a pig iron results which contains about 4 per cent carbon, 1 per cent silicon, 1 to 2 per cent manganese, 0.1 to 0.4 per cent phosphorus, and 0.03 to 0.10 per cent sulfur. To obtain a sufficient yield of iron from the ore it is necessary that the reducing process be carried as far as possible, with the result that the impurities mentioned accompany the reduced iron. Second: to convert this iron into steel it is necessary to oxidize a part of the iron in eliminating the impurities to the extent desired for the particular product being made. In eliminating these impurities by oxidation a certain amount of iron oxide (FeO) dissolves in the steel. This dissolved FeO reacts with the metalloids, except sulfur, and to eliminate them to the desired extent it is necessary to leave a considerable amount of FeO in the metal. The reaction of iron oxide with silicon, manganese, and phosphorus results in the formation of the oxides of these elements. The oxides enter the slag and the extent of elimination of the elements depends on certain equilibria between the slag and the metal. The reaction of FeO with carbon results in the formation of the gases CO and CO, which, after saturating the metal, pass into the furnace gases. Third: after the iron has been purified to the desired extent as far as the elements listed are concerned, it is necessary to deoxidize the bath to remove the FeO, which is the vital factor in gas formation as the steel solidifies.

Jan 1, 1957

It should be stating the æbleeding obviousÆ to say that the most efficient method of recovery must be used during the testing and evaluation phases of an orebody. Furthermore, the company will be literally throwing away money by not using the most efficient recovery plant during mining. This is especially true in the case of a low concentration/high value commodity such as diamonds. Unfortunately, this economic recovery criterion is not always the driving force. Some inexperienced companies think that they can preserve capital by using cheaper, and generally less efficient, recovery plants to mine their product. This philosophy is invariably a fallacy. Furthermore, it is also important to use the correct sized plant for the proposed task. It is no use trying to use a small testing plant to treat large quantities of ore, as this may result in loss of recovery efficiency. The converse is equally true.

Jan 1, 2004