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By Y. Wang, S. Liu, K. Jiang

China is the world’s largest producer and consumer of non-ferrous metals. In recent years, significant progress has been made in research and commercial application of pressure leaching technology to produce some nonferrous metals. Research and development activities include a low-pressure, low-temperature leaching technology for complex copper concentrates, a hematite process to treat pressure leach solutions from zinc concentrates, and a pressure leaching - solvent extraction process for molybdenum and rhenium. Examples of commercial practices include a two-stage pressure leach technology in a zinc plant in Danxia, a direct leaching technology in a zinc plant in Zhuzhou, a high pressure acid leaching process for a nickel laterite project in RAMU, and a pressure leaching technology to treat arsenic sulfides in a plant in Guixi. The development of pressure leaching technology for the recovery of lead, vanadium, gallium, germanium, and precious metals in China will also be described in this paper.

Jan 1, 2015

By L. S. Beck

"IntroductionThe Beaverlodge District is an important mineralogenic province of pitchblende and occupies about 1300 square kilometres centred on Beaverlodge Lake near the north shore of Lake Athabasca in northwest Saskatchewan (Fig. 1). Uranium City is the main settlement of the area and is serviced by scheduled aircraft from Edmonton, some 700 km to the southwest, and from Prince Albert which lies a similar distance to the south.During the summer, boats and barges supply the area from the railhead to Fort McMurray via the Athabasca River and Lake Athabasca, a distance of about 550 km. For the past few years a winter road has been maintained across Lake Athabasca to Cluff Lake to connect with Highway 155.The topography of the area is typical of the Precambrian Shield with generally low relief and a disorganized drainage of numerous lakes separated by hummocky rock ridges, muskeg and drift-covered areas. Local topography in the area is, however, extremely rugged, particularly south and east of Beaverlodge Lake, where resistant rocks form prominent hills and ridges extending as much as 180 m above lake level. Rock exposures are abundant and form over 50 per cent of the land area.History of Exploration and DevelopmentEconomic interest was first aroused by Tyrrell (1896) who described an occurrence of iron formation at Fish Hook Bay; however, subsequent evaluation of the deposit indicated it to be uneconomic."

Jan 1, 1986

By Raj K. Rajamani, Nikhil Dhawan

"Agglomeration has become common pre-treatment step to improve heap leach percolation thereby recovery, the fundamental understanding of the agglomeration process for crushed ores is still lacking. Agglomeration is required for ores which either contain excessive amounts of clay or an excessive quantity of fines generated during mining and crushing. Numerous experiments have been carried out in laboratory scale batch drums using different ores. It has been found out that experimental agglomerate size distributions exhibit self-preserving spectra. The self-preserving/ similarity distribution of the agglomerates is found to be independent of operating conditions and is uniquely determined by the size enlargement mechanism. An empirical model based on the absolute difference between moisture applied and optimum moisture was developed. This model uses self-preserving spectra in the form of a Rosin-Rammler distribution function to predict size distribution at different operating conditions. The empirical model was considerably easier to work with plant scale agglomeration drums. Also, a test known as dip test is developed which improves fundamental understanding of the agglomerate formation and growth mechanisms. This test also provides the progeny size distribution of each agglomerate size. The progeny size distribution was analyzed with a model that partitions the particles into a host and guest category. The ensuing partition coefficient identifies the behaviour of a particle as a host for other particles or a guest layering on other particles. This concept helps in identifying the type of agglomerate that would result for a specific feed size distribution. INTRODUCTIONHeap leaching is one of the hydrometallurgical processes that have served as a green and economically viable process for the treatment of low grade complex ores of copper, uranium, nickel, silver and gold (Dhawan et al., 2013). Heap leaching appears to be a favorable candidate for the least energy consuming process for low grade ores. In heap leach operations nowadays a pretreatment step known as crushed ore agglomeration has been implemented (Dhawan et al., 2013). A bed of agglomerates improves the uniform percolation of solution through the heaps of ore. Therefore, it was possible to treat wastes and mill tailings via agglomeration and heap leaching. Agglomeration pretreatment is required for ores which either contain excessive amounts of clay or an excessive quantity of fines generated during mining and crushing (Bouffard, 2005; Dhawan et al., 2013).While agglomeration has become common practice pretreatment step in heap leach operations, the fundamental understanding of the crushed ore agglomeration process is still lacking. The author reviewed publications up to 2012 on the crushed ore agglomeration process and did not come up with modeling studies on the topic (Dhawan et al., 2013). Some of the possible reasons can be the stochastic nature of the process, experimental difficulties, and lack of instrumentation for fundamental studies."

Jan 1, 2016

By Erik Spiller

"Water and cyanide are highly contentious and conflict issues that many gold mining companies encounter worldwide when dealing with local farming communities, industries and cities competing for water as well as non-government and government organizations. Historically, the gold industry has used processes that required minimum amounts of water to treat and recover gold at locations around the world. Examples are dry grinding for refractory gold treatment in the late 1800s and early 1900s and dry blowing in arid/desert regions to recover alluvial gold. In recent times, new dry processing equipment has been developed and include equipment such as air tables and jigs. Researchers have also modified a Knelson concentrator to concentrate gold from dry solids. High pressure grinding rolls (HPGR) with air classifiers are used to treat industrial minerals and pilot trials have shown that the technology can be applied to comminute refractory gold ores ahead of roasting. Dry stacked tailings is being applied on gold mines to reduce overall water consumption This paper will review the available technologies that in combination may be able to substantially reduce the quantity of water used in the processing of gold ores.INTRODUCTION Water makes up most of the world: the planet is 75% water. Some 97.5% is saline water largely in the oceans, so that only 2.5% is fresh water and useful for human needs. The demand for water is driven primarily by population and concomitant economic growth. Overall, some 70% of the water withdrawn from the environment is used in agriculture, 20% by industry, 7% by households and 3% for mining (Brown, 2003: Maupin et al., 2010). Whilst the water needs of the mining industry are minor compared to those of agriculture, an operating mine requires a relatively large quantity of water on a daily basis to carry out operations. Mining activities are often located in remote, arid environments, with limited access to water. There are a multitude of water resources available to the mining industry for its needs. However, much of this water is saline and over the last two decades there has been a continual decline in water quality (i.e. salinity has increased). In today‘s world, there are enormous internal and external pressures to reduce water consumption at a mine, and/or alternatively use water not considered a resource by the local community. Strategies to meet these objectives can be achieved by implementing good water management practices, by recycling process water, reducing water losses by evaporation and seepage (i.e. by increasing and improving dewatering practices) and employing new technologies such as dry stacking and dry processing (Dunne, 2010)."

Jan 1, 2017

By Ltd. (CYMCO) Technology Center Yunnan Metallurgical Group Co., S. Jian, T. Song, J. D. Miller

"As sulfide zinc ore deposits become exhausted, nonsulfide zinc ore deposits become the other resource for zinc production. However, flotation for zinc recovery from nonsulfide deposits is much more difficult than the flotation of sphalerite from sulfide deposits and may become an option for zinc production only if a suitable processing technology is developed. In this regard, research efforts are being devoted to the flotation of nonsulfide zinc oxide minerals. Some common methods which have been used for the flotation of zinc oxide minerals include sulfidization-flotation, activation, and direct flotation with anionic and cationic collectors. The traditional flotation techniques have low efficiency and difficulty in separation and recovery of the zinc minerals from gangue minerals, for example, smithsonite (ZnCO3) from other carbonate gangue minerals and hemimorphite (Zn4Si2O7 (OH)2·H2O) from silicate gangue minerals. In this study potassium lauryl phosphate was evaluated as a collector for the flotation of nonsulfide zinc minerals. Results from contact angle and microflotation experiments at pH 6–9 show that hemimorphite (Zn4Si2O7 (OH)2·H2O) can be floated from quartz and that smithsonite (ZnCO3) can be floated from calcite. However, when dodecylamine, which is a common collector reported in literature for the flotation of nonsulfide zinc minerals, was used as collector, no significant difference between nonsulfide zinc minerals and gangue minerals was observed at any pH value. Initial evaluation suggests that potassium lauryl phosphate is effective at low concentration and may be a promising collector for zinc oxide mineral flotation.INTRODUCTIONBefore the twentieth century, zinc was mainly produced from nonsulfide ores (Large, 2001; Gilg, Boni, & Cook, 2008). With the development of differential flotation processes in the late 19th century major production switched from nonsulfide zinc sources to sulfide zinc ores (Hitzman, Reynolds, Sangster, Allen, & Carman, 2003; Gilg et al., 2008). However, as it is becoming more difficult to find new sulfide ores, recovery from nonsulfide deposits is being considered. Nonsulfide flotation for zinc recovery is much more difficult than the flotation recovery of sphalerite from sulfide deposits and may become an option for zinc production if a suitable technology is developed. Zinc and lead oxide ores are difficult to beneficiate ores due to their similar floatability with gangue, high solubility in water, and the influence of slimes (Fa, Miller, Tao, & Li, 2005). In order to improve the performance of oxidized minerals, lots of effort is being devoted to this field of study (Ejtemaei & Mahdi, 2014)."

Jan 1, 2016

"Beneficiation of low grade ores is the process of increasing the grade of a mineral through unit operations that remove and separate the waste (or gangue) material from the valuable mineral that can then be used for further processing or direct use. Important factors when deciding upon a beneficiation program are the feed grade, mass yield and the metal recovery. As lower grade ores are being processed beneficiation is a critical process. How predictive is laboratory test work for “as built” operating projects? Beneficiation includes all or some of the available unit operations to produce a beneficiation flow sheet i.e. associated unit operations including but not limited to optical sorting, radiometric sorting, crushing and screening, coarse cobbing, jigging, dense media separation (DMS), spirals, magnetic separation, flotation, thickening, filtering and drying. Reference to specific projects and the approach developed in formulating a beneficiation flow sheet and a comparison of difficult and simple beneficiation flow sheets are cited. INTRODUCTIONReserves of high-grade iron ores are reducing all over the world, at an alarming rate, over the years as a result of the rapid increase in demand for steel particularly from Japan and then China. The recovery of mineral value from the low-grade ores using present technology is more expensive than DSO ores due to high energy and capital costs. Beneficiation is defined as a variety of processes whereby extracted ore from mining is reduced to particles that can be separated into mineral and waste.Various physical properties of an ore can be exploited to separate a low grade fraction including variation in hardness, density, reflectance, conductivity and magnetism.""Beneficiation"" of iron ores includes concentration, generally by physical removal of unwanted gangue. Also considered beneficiation is the regulation of product size, or other steps such as agglomeration to improve its chemical or physical characteristics prior to smelting."

Jan 1, 2012

By H. W. Wevers

This paper is the result of an intensive literature search and practical study of the problems experienced by a mining company with the frame cracking of their large-tonnage haulage trucks. It explains the advantages of particular HSLA steels for applications in the welded structures of such equipment. Examples of existing welds in truck frames are analyzed. Modern fatigue models and linear elastic fracture mechanics techniques are explained.

Jan 1, 1978

By H. M. Woodrooffe

IT IS WELL KNOWN that chrysotile asbestos from various occurrences exhibits varied physical properties and certain differences in chemical corn position, both of which conditions may have an important bearing on the industrial utilization of the fibre. The usefulness of a harsh fibre in the manufacture of asbestos cement products and of low-iron fibre for certain electrical uses are examples. It is also .possible to obtain a fibre with a texture too harsh and brittle to be of economic value. Much research into the structure of the mineral and to a lesser degree observations relating the water of combination to certain physical properties have ?been reported. This paper is an attempt to show that the pyrolysis of ?chrysotile takes place in three stages and that the conditions of pyrolysis are peculiar to the fibre and may afford some clue to the variations in physical properties of asbestos fibres which affect their utilization.

Jan 1, 1956

By L. A. Homeniuk, R. J. McH. Clark

"The Maurice Bay deposit, the Stewart Island showing, the Fond-du-Lac deposit, the Middle Lake showing and the Nisto deposit are located on the North Rim of the Athabasca Basin. They are probably unconformity-related. These occurrences tend to be small. The Fond-du-Lac and Maurice Bay deposits are the largest and contain 450,000 kg and 650,000 kg of U10 8 respectively.Pitchblende is the main uranium mineral of all the occurrences, except at Middle Lake where autunite predominates. A II of the deposits are overlain and partially hosted by the Manitou Falls Formation of the Athabasca Group, except the Nisto deposit which is entirely within basement rocks, and the Maurice Bay deposit which is partially within the basement and overlying the Fair Point Formation of the Athabasca Group.The North Rim deposits are considered to be genetically similar to the other unconformity-type deposits found in northern Saskatchewan. It is suggested that a mechanical concentration of uranium may have occurred in heavy mineral beach sand type placers. The stability of the uranium minerals may have been enhanced by special local conditions. The fossil placers, after hydrothermal alteration and enrichment, would form the apparently ""rootless"" occurrences of uranium found totally within the sandstones above the unconformity.IntroductionAt least five deposits and showings and one train of mineralized glacial erratics of unknown provenance have been located on the North Rim of the Athabasca Basin from Maurice Bay in the west to Black Lake in the east. Distributed over a distance of 250 km, (Fig. l), they occur near the edge of the Basin, and are probably unconformity-related. The following have been identified from west to east (Fig. 2): The Maurice Bay deposit, the Stewart Island showing, the Isle Brochet train, the Fond-du-Lac deposit, the Middle Lake showing, and the Nisto deposit."

Jan 1, 1986

By Robert P. Dufresne

Electrolytic cells are used in electrowinning (EW) and electrorefining (ER) of non-ferrous metals such as zinc and copper, and are a critical part of the purification process. The cell is a large basin and has an electrolyte or aqueous solution, an anode and a cathode, an insulator, and incoming high amperage. Cells are exposed to unfavourable internal and external factors that have a direct impact on their lifespan. Their deterioration can be caused by incorrect polarity, insufficient magnitude, their construction, tension stress, thermal shock, corrosion and other, and their maintenance and replacement can be time-consuming, costly, difficult and environmentally unsafe. Occupational health hazards and dangers posed by the maintenance and removal of the cell should also be taken into consideration. Modifying the design and fabrication method of the cell, using chemical-resistant reinforcement, and increasing tensile and mechanical strength will defer maintenance for a very long time. This can be achieved by a double hull system that comprises full-length composite reinforcement, polymer concrete reinforced with fiberglass pultruded rods and rebars, fiberglass structural layers, and special resin matrices. This will provide protection against thermal shocks, corrosion, leakage, cracks. The design of this cell incorporates a lifting system that will afford quick and easy install without having to move a great number of cells in close proximity, since it is strong enough to stand on its own and not have to be bonded to adjacent cells. As well, the cell can be anchored with ease as it remains stable. This is especially important because space is limited to lift and manoeuver between the cell and the double-girder overhead travelling cranes. The lifting system can also prevent electrocution and loss in product quality, while increasing efficiency and safety in the workplace. Considerable savings in terms of production downtime are also part of the equation. INTRODUCTION Maintenance and replacement of electrolytic cells in electrowinning and electrorefining are operations that pose many challenges, health and safety concerns, and give rise to substantial operational costs. These problems have existed since time immemorial. Electrolytic cells are made of conventional concrete or polymer concrete, and because of the very nature of their composition and their exposure to severe and environmental conditions, their lifespan is short. Although polymer concrete is composed of high-quality materials, and has good thermal stability and resistance to chemicals, nonetheless, maintenance is frequently required in order to maintain the integrity of the cell and to ensure the quality of refined metals. Repairing concrete is a non-permanent solution as cracks will reappear, and every repair weakens the integrity of the cell a bit more, until it reaches a knock- down point and the structure is compromised. The cell needs to be replaced, otherwise the cell will collapse.

Jan 1, 2019

By Anthony A. Zoobkoff

Gotcha! ? What Did I Just Agree To? ? You can?t repeat or use anything you heard. ? Did you agree before you knew what you were going to be given, told or shown? ? If you knew what you were to be given, told or shown, would you have still agreed?

May 1, 2013

By Jeffrey D. Oke

While significant progress in underground construction engineering has occurred in the past few decades, a number of fundamental deficiencies persist regarding the recognition, prediction, and mitigation of underground construction hazards associated with complex geological conditions in rock and soil works, such as tunnelling. Many of these shortcomings could be addressed by improving geomechanical models which, in turn, would provide more realistic frameworks for determining input parameters for design analysis. This would improve predictions of construction efficiency for tunnelling and the formulation of more accurate modelling techniques (2D, 3D and 4D) required to optimize the design of engineered rock structures. This research focuses primarily on the issues related to forepole temporary tunnel support within weak rock masses. This research attempts to determine how best to numerically model forepole support. The behaviour and mechanics of forepole support has not been quantified and/or optimized. As well, there is a lack of in-situ and/or laboratory forepole and weak rockmass interaction parameters available. In terms of numerical modelling, there is a lack of understanding of the use of proper interaction parameters associated with the forepole and the rockmass. The parametric study that has been conducted by the authors demonstrates the influence of each of the forepole-rockmass interaction parameters and their sensitivity. Introduction

Jun 1, 2012

By Cindy Schiewek

Industrial injury occurrences are an ongoing concern for Mine Operators. Along with the personal suffering of injured workers comes an increase in compensation and productivity costs. Growing recognition of repetitive stress and bodily injuries, accompanied by recent studies, validates the assumption that a relationship exists between ergonomic injuries and machine design. Intuitively, there is a belief that an ergonomically designed machine will reduce repetitive stress injuries through design and education however; quantifying this belief has been a challenge for Mine Operators. Sandvik Tamrock has undertaken a project aimed at developing a business model to assist in quantifying the benefits of ergonomic intervention. This model focuses on distinguishing and quantifying this method of intervention to allow for a better evaluation of the machine. For simplicity, the project initially focused on the Face Drill Jumbos. The target of the project was three fold: !" Recognition of the cost drivers for compensation; ergonomic injuries !" Identification of the relationship between ergonomic machine design, and the decrease of the negative effects associated with the cost drivers !" Systematic prioritization for ?prevention by design? The project findings substantiate the expected reduction in injuries and compensation claims. Based on all ergonomic intervention studies conducted, each case showed a reduction in compensation cost; through prevention by design, one can reduce the amount of potential risk. The paper addresses the resources and methodology used, along with the findings and its relevance to the issues that face the Mining industry.

May 1, 2003

By K. C. Corin, Z. G. Song, J. G. Wiese

In the present study the effect of using different grinding media, viz, ceramic balls, forged steel balls, 15% Cr steel balls, stainless steel and mixture of stainless steel and 15% Cr steel balls (50:50) on the flotation performance of a Platinum Group Mineral (PGM) UG2 ore was investigated. Test work was conducted using a laboratory scale horizontal tumbling mill and a batch flotation cell. Power draw to achieve a specific P80 was determined for each media type. Changes in flotation behaviour were evaluated in terms of particle size distribution, water recovery, solid recovery and valuable mineral recovery. pH, Eh and DO levels were also measured. Grinding products of five different media produced similar solids and water recovery, which is indicative of the froth characteristics, but the grades and recoveries of PGE and chromite were different. The product obtained when using ceramic media showed the best flotation performance, producing the highest PGE recovery and the lowest Cr2O3 recovery. The products obtained when using stainless steel balls (SS) produced the lowest PGE recovery and highest Cr2O3 grade and recovery. The paper proposes possible reasons to explain these observations which may have significant importance for the operation of a PGM concentrator.

Jan 1, 2015

By N. A. Warner

Virtually zero gas emission smelting is promoted as a means for securing environmental advantages and the general public’s acceptance. Concerns about climate change will increasingly make it more difficult for new primary metals projects to come to fruition unless greenhouse gas emissions are decreased. Assuming a sustainable market for sulphuric acid is not locally available, the next best option is high temperature reaction of strong SO2 with limestone or dolomite. This is followed by CO2 liquefaction and disposal either underground or in the deep ocean. The Voisey’s Bay nickel project is cited as an example where appropriate location of a new smelter close to large dolomite or limestone deposits would lead to a virtually zero gas emission operation. Most of the electrical energy required for producing technically pure oxygen and for liquefying CO2 and transporting it to disposal can be derived from smelting a bulk sulphide concentrate and then reacting SO2 at high temperature. Provided the smelter gases are properly cleaned before sulphur fixation, the sulphated stone should be uncontaminated and environmentally benign and possibly of use in the building and construction industry.

Jan 1, 1999

By Grant S. Diamond

THE BIBLIOGRAPHY on the use of static electricity in mineral beneficiation consists largely of patents. Some references are found in mineral textbooks, but very little data on flow-sheets of commercial installations are known to the writer. As a matter of fact there have been relatively few successful commercial applications of importance. Johnson prepared and published a Table showing the polarity and static field intensity requirements of many minerals. There have been reports of successful beneficiation of rutile, zir-con, coal, potassium chloride, and phosphate rock. Otherwise, the field of success has been very limited. This may be due to three reasons: first, the mining industry has been averse to dry processes, be-cause of dust nuisances in dry crushing; second, the electrostatic processes used in the past apparently developed no substantial economic advantages; and third, because flotation or other . methods have proven successful on many minerals, the industry has not felt the need for a radically different process. In the feldspar industry there was ?an attempt at electrostatic beneficiation about twenty years ago which was based on the use of fluoride fuming of the pegmatite head feed, in order to make the mineral reactive in a static field. This process was originally said to be successful, but was discontinued because of corrosion damage to machinery. Another effort by use of a chemical additive such as an or-ganic hydroxyl compound has also been attempted. Neither of these processes is known to be in use today.

Jan 1, 1957

By Shek N. Lau, Nicola Samman

"Enclosed gear cases on board heavy mining equipment have traditionally been lubricated with regular heavy duty gear oils. However, equipment manufacturers, have recommended the use of an ISO-1000 gear oil for this application to ensure adequate lubricant film strength, especially at the higher end of the working temperature range. The majority of these ISO-1000 gear oils are based either on residual/asphaltic oil or synthetics, primarily higher viscosity polyalphaolefins. Although the performance of these lubricants has been satisfactory, they suffered other shortcomings that equipment users have lived with over the years.The major requirement at the user’s mine was to provide lubrication for the shovel Hoist gear case. Within such a gear case design, the gears and the roller bearings, that have different lubrication requirements, are lubricated with the same lubricant. Several lubricants were used, light gear oils as well as the recommended ISO-1000 heavy gear oils. On the one hand, the lighter oils performed adequately for the lubrication of the bearings that formed part of the enclosed gear system. These lighter oils did not perform as well for the lubrication of the gears due to their lower viscosities, resulting in shorter gear servicelives.On the other hand, the ISO-1000 gear oils performed well for the lubrication of the gears, but were too viscous to creep into the bearing elements to lubricate them adequately, especially during the cold northern Canadian winters. This resulted in catastrophic bearing failures and secondary damages to the gears.The challenge, then, was to formulate a lubricant which met the 1000 cSt at 40°C viscosity requirement as stipulated by the equipment manufacturer, while satisfactorily lubricating the bearings at the full working temperature range. This was achieved by the development of a semi-fluid grease lubricant, which has proven in field trials to give adequate performance in this application for the lubrication of both the bearings and gears down to -40°C.This product met the equipment manufacturer’s performance criteria and resolved, to a large extent, leakage of the lubricant through seals experienced with the use of conventional and synthetic gear oils.Although the main performance criteria of the fluid was its capability to lubricate the “Hoist” gear case, it was also used during the field trial in other gear cases on board the shovel to test its full capabilities.This unusual alternative lubricant was field tested and evaluated for more than two years. Based on this assessment, the product was reformulated to improve its fluidity, slumpability and the settling of debris/wear metals to the bottom of the gear cases. This reformulated softer grade, a semi-fluid grease, has been performing satisfactorily for more than eight months and is still undergoing longer term assessment."

Jan 1, 1996

By Yoshimasa Funakawa, Kazuhiro Seto, Akio Kobayashi

A new hot rolled high strength steel consisting of ferrite matrix and nanometer¬sized precipitates was developed. The ultra fine precipitates were identified as TiMoC2, and the strengthening by the precipitates was evaluated more than 300MPa in case of TS/800MPa grade steel. Due to the strengthening effect of the ultra fine precipitates, alloy elements for solid solution hardening can be reduced. It is notable that the steel shows very high yield strength (730MPa in case of TS/800MPa) and very high local elongation leading to excellent stretch flange formability at the same time. The mechanical properties of the steel are attractive for chassis parts and structural parts of auto body. The steel has been produced commercially, and applied to the parts successfully.

Jan 1, 2004

By Jan W. Merks

The objective of metrology in mineral exploration is to derive unbiased confidence limits for masses of metals contained in reserves and resources. Sets of test results for gold and silver determined in pairs of interleaved bulk samples give unbiased confidence limits for the central value of each metal. The same sets of test results show how to verify spatial dependence by applying Fisher?s F-test to the variance of a set and the first variance term of the ordered set. A significant degree of spatial dependence gives a higher degree of precision for the central values of gold and silver. Plotting variance terms of an ordered set against the variance of the set and its lower limits of asymmetric 99% and 95% confidence ranges gives a sampling variogram. Sampling variograms put in plain view where spatial dependence in sampling units or sample spaces dissipates into randomness. The application of statistical methods to test results for sets of ordered core samples within boreholes, and for sets of ordered ore volumes within profiles, plays an important role in defining reserves and resources.

Oct 1, 2009

By J. Cayouette, . Blatter, P. Cousin

The Laronde mill was commissioned in 1988 and has been treating the Laronde Perim ore since 2000. The Laronde plant, situated in the Abitibi region of Quebec, has experienced mill expansions to accommodate 7500 mtpd and to recover gold and silver as well as important amounts of base metals (Cu, Zn, Pb). Ten sequential metallurgical and environmental processes are responsible for metals recovery and process viability. Over 200,000 ounces of gold, 4,5 million ounces of silver, 7000 tonnes of copper, and 78,000 tonnes of zinc are produced annually. In 2008, the Goldex plant began trucking high wade (35-45 Wt Au) pyrite sulphide concentrate (TCGO) for gold extraction at a newly constructed treatment plant, increasing gold output at Laronde by 40,000 ounces. In 2009, the high gold wade Lapa ore processing facilities were annexed to the Laronde plant increasing output by 120,000 ounces of gold. TCGO and Lapa productions are forecasted until 2018 and 2015 respectively, with known reserves of each mine. Today, up to 140 permanent employees run and optimise the Laronde plant operation. As a result, Laronde has intricacies intrinsic to a large and varied operation. The paper will outline the metallurgical highlights, challenges, and future outlook related to the treatment of each ore type (Laronde, TCGO, and Lapa)

Jan 1, 2011