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By T. R. Raponi

"The Williams Mine, Canada's largest gold mine, processes over 6,000 t/d of ore utilizing SAG/ball milling, leaching and CIP, carbon stripping, electrowinning and refining to produce gold dare bullion.Grinding accounts for over 50% of milling costs with grinding media, power and mill liners making up over 75% of grinding costs. Since 1991, several changes in these areas have been made which have significantly reduced costs, while fineness of grind and mill recovery have both been increased.This paper discusses the changes made in the grinding circuit over the past few years and assesses their impact on operating costs and mill operations.IntroductionThe Williams Mine is located in the Hemlo area of northwestern Ontario, about 40 km east of Marathon. It is operated by the Williams Operation Corporation, which is equally owned by Teck Corp. and Homestake Canada Inc. Canada's largest gold mine, the Williams Mine commenced operation in October 1985 at a rate of 3, 000 t/d. Mill throughputs have typically exceeded design, averaging 3, 397 t/d in 1986, and 3,380 t/d in 1987. In August 1988, production was increased to 6,000 t/d. Throughput averaged 4,212 t/d in 1988. Production increased over the next few years averaging 5,477 t/d in 1989, 6,248 t/d in 1990, 5,987 t/d in 1991, and 6,283 t/d in 1992. With a recovery of over 95.5%, production for the first three quarters in 1993 is averaging 6,408 t/d.GeologyThe main ore body is a steeply dipping conformable zone of microcline-quartz-muscovite rock. It occupies the contact zone between hanging wall metasedimentary rocks and foot wall felsic quartz feldspar porpyritic rocks of possible volcanic or subvolcanic intrusive origin. The ore body is enveloped by muscovite schists which are thickest on the footwall side. The schist is enriched with tourmaline, pyrite, and green mica containing vanadium and barium. The ore body contains pyrite and barite which occurs mostly in laminae and bands to veinlets and breccia fillings. The gold occurs as free (native) grains, 20 to 30 µm in size at grain junctions of the microcline and quartz. Visible gold is rare in the main zone. There are commonly two or more discernable layers of economic value which are separated by weakly gold mineralized material which usually consists of muscovite schist, barite rich zones or sulphide poor-microcline-quartz rock and in the upper and western fringes by biotite rich schist with feldspathic fragmental characteristics. Molybdenite is a common constituent as very fine disseminated grains in the microcline-quartz rock and is most prominent with gold enrichment. Stibnite and realgar are two of the more common accessory sulphides."

Jan 1, 1994

By Kym Runge, Emmy Manlapig

"The objective of an industrial flotation circuit is to separate valuable minerals from non-valuable minerals utilising differences in their flotation recovery rate. Regrinding and reagent addition are particle modification processes which are employed within these circuits to maximise the flotation selectivity of one mineral with respect to the others present in the ore feeding the process.Batch test nodal analysis, or the ability to compare floatability through mathematical combination of laboratory batch flotation test results, is a powerful technique for assessing the effectiveness of particle modification processes on ore floatability in industrial flotation circuits.In this paper, the use of nodal analysis is demonstrated within an industrial flotation circuit. It is used to show that regrinding and staged reagent addition within Teck Cominco’s Red Dog zinc retreatment circuit is beneficial to pulp flotation selectivity. Optimisation of these processes could potentially improve the zinc recovery within the circuit. Lime addition, which is periodically employed to depress pyrite in the circuit, was found to depress sphalerite in preference to pyrite and to result in poorer metallurgical performance in the circuit.INTRODUCTIONThe objective of an industrial flotation circuit is to separate valuable minerals from non-valuable minerals utilising differences in their flotation recovery rate.Different minerals can only be effectively separated using flotation if they are sufficiently liberated from each other (i.e. do not co-exist within the same particles) and have a sufficient difference in surface hydrophobicity. Size reduction processes and chemical addition are utilised before and within a flotation circuit to achieve sufficient particle liberation and to maximise differences in mineral hydrophobicity. In effect, the objective of these processes is to maximise the flotation selectivity of one mineral with respect to the others present in the ore feeding the process."

Jan 1, 2004

By J. E. Nesset, L. S. Urbanoski, J. R. Goode

"The benefits and advantages of pre-competitive, collaborative industry/university research are not always well appreciated. This paper presents the case study of a current collaborative project between CAMIRO-Metallurgical Processing Division and McGill University that is investigating the understanding and prevention of sphalerite activation in lead and copper-lead flotation circuits. The benefits of the research findings to the sponsors can be maximized by an approach which links the researchers themselves with the sponsors at frequent, interactive project review sessions. Some examples of the findings and their application to industry are also presented along with a general update on CAMIRO-MPD.INTRODUCTIONThe history of Canadian efforts in the area of collaborative pre-competitive research is not long when compared to Australia (AMIRA) and Britain (MIRO). AMIRA (Australian Mineral Industry Research Association) began over 40 years ago and has had a well recognized role in bringing together industrial sponsors and researchers to fund a large variety of very significant development projects in that country, The total AMIRA funding effort for mineral processing work currently exceeds some $Aus 40 million with new projects valued at about $Aus 12 million initiated each year. This high level of commitment by industry has contributed to establishing Australian researchers and their facilities as among the best in the world.Canadian companies have traditionally funded much of their R & D in-house with extensive facilities and large funding commitments. The past 2 decades have seen most of these facilities disappear. The current situation is one in which only the largest integrated metal and mining companies have retained their own R & D groups (e.g. INCO, Falconbridge, Noranda). Industry-funded research at universities was primarily through individual efforts by the mining companies and rarely included collaboration with other mining companies, equipment or chemical suppliers, or engineering firms."

Jan 1, 2001

By A. E. Hall

"This paper summarizes findings of a two-month investigation in Zambia and Zimbabwe and a one-month visit to Britain in1990-1991. United States contacts have supplied information about that country.Zambia's political unrest and severe devaluation, combined with developments in Namibia and South Africa, enhanced staff recruiting problems in the School of Mines. Zimbabwe has a strong and developing mining department. The departments of mining in the United States and Great Britain are readjusting and contracting due to the reduction in the scale of the industry.The above factors are reviewed and their impact on the countries evaluated.IntroductionCanada trains the majority of its mining engineers domestically but a significant number are recruited from other countries. Examination of the qualifications of 200 professional engineers registered in the mining discipline in British Columbia showed that125 received their first degree from a Canadian university, 33 graduated from institutions in the United States and 42 from the rest of the world including 30 from the United Kingdom. This is a rough and-ready sample but it indicates that developments in the education of mining engineers in the United States and in Britain are relevant to the Canadian mining industry.The recent changes in the world economy and political structure have significant implications for the mining industry and for the supply and training of engineers. Change in eastern Europe coupled with the downturn in mining, especially in the European coalfields, has enabled many engineers to travel freely to the West. The low gold price and the legislative changes in Africa that have improved access to education for Africans with the ability to fill responsible positions, have reduced the South African mining industry’s overseas recruitment to a minimal level. The Australian recession has also lowered their recruitment of mining engineers from other countries."

Jan 1, 1993

By Hasan Ozturk

Laboratory testing examined the effect of a variety of intrinsic rock properties and environment conditions that influence the adhesive bond between rock and thin spray-on liners. The liner materials used for these tests were Tekflex, provided by Fosroc, Castonite, provided by Rohms and Haas Co., Rockweb provided by Spray-on Plastics, and CS 1251 2K, provided by Master Builders. Some of the variables examined include: rock strength (tensile/compressive strength) rock mineralogy, rock surface roughness (grain size, fracture/joint roughness), and surface contamination (oil, water or dust). Under optimal conditions, adhesive strengths reaching at least 3 MPa can be achieved. Where the rock surface is contaminated with dust or the rock is weak in tension, it may be difficult to reach adhesion strengths of 1 to 1.5 MPa.

May 1, 2004

By M. L. Goble

"Inco Metals Ltd. (Manitoba Division) operates a mining, milling, smelting and refining complex, 500 miles north of Winnipeg in central Manitoba. The Thompson Mill is presently operating at 12,000 S.T.P.D. on ore from both underground and open pit mines. The ore is treated in two separate milling and flotation circuits utilizing a common crushing system which is located inside the main mill building. The milling facility employs approximately 43 operating employees, 30 maintenance employees and 20 staff in supervisory or process development roles.In recent years an increasing awareness of the potential hazards of contaminants in the work place has made it mandatory that all employers maintain careful and accurate records of the work environment to which each employee has been exposed during his working career.The importance of this record keeping and general observation of the work place cannot be over emphasized. Proper monitoring of the work place provides an accurate and complete record of the contaminants and physical agents to which an employee is exposed during his work career. This can aid in studies which might be conducted in the future and can also be used as a basis for instituting improvements to the workplace."

Jan 1, 1980

By F. Malek

At Creighton Mine, magnitude events are a regular occurrence due to depth and major seismically-active structures. Over the last ten years, major advances have been made in research and development to develop strategies for the management of these major events. Today, the number of rockbursts has been drastically reduced at the mine and damage due to seismic events, when they occur, is often minimal. This paper describes the evolution and implementation of appropriate geomechanics strategies, designs, and practical ground control measures undertaken for the management of seismicity at Vale Inco?s Creighton Mine. A description of the research and development approach, implementation, and ground control strategy is provided for placement of enhanced support systems to manage the consequences of magnitude events at Creighton

May 1, 2009

By Ron Board

"Probably the only thing that can he said about conveyor belt scales without fear of contradiction is that they have been responsible for as much or more puzzlement, argument and frustration than almost any other piece of equipment commonly found in ore processing facilities. To be sure, there are certainly a good number of satisfactory installations, some of these having been achieved through forethought and careful consideration in the early stages of plant design, while others seem to owl their success to what seems to be little more than good luck or white witchcraft; and it might also appear that black witchcraft or other gremlins are solely responsible for the poor performance of many belt scales that enjoy well-designed installations with apparently good operating conditions.This paper is intended to acquaint users with the major operational reasons why belt scales seem so fickle (and downright ornery too), and establish some reasonably simple test standards against which the performance of scale hardware can be measured. Then it shall be shown how the design flexibility of electronic scale systems can offer particular advantages in overcoming some of these everyday problems in a practical way, and without undue inconvenience to plant operations."

Jan 1, 1975

By D. E. M. Plaumann, B. S. Fee, R. D. Hansen, R. R. Klimpel

"The steps from experimental curiosity through to commercial product can be slow and tortuous in spite of the quality of the technological advances offered by the new development. Data generation and interpretation need to be done in lab tests as well as full-scale evaluations and, in each, the advantages of the new reagent must be clearly identifiable and measurable.The Dow Chemical Company has patented a novel new collector for the flotation of zinc. Fl (2-hexylthioethylamine hydrochloride) has several unique structural features that suggest atypical mechanisms for zinc collection. Laboratory data have demonstrated significant flexibility with respect to grade and recovery balance at dosages lower than those typically used for xanthates.In mill trials, the same phenomanon is evident - the choice between high grade and high recovery allows one to select the desired quality of zinc concentrate. One trial in particular was run over a three month timeframe and Fl gave improvements in recovery of 2.5% and a reduction in lead levels with less than 0.5% loss in grade. The dosages of other reagents in the flotation circuit were also reduced.Data demonstrating improved recovery and grade in lab trials will be discussed. Extensive data from the mill trial will illustrate how Fl works in both rougher and cleaner circuits."

Jan 1, 1990

By Jaeheon Lee, Junmo Ahn, Jiajia Wu

In this project, low grade copper ore samples were obtained from two mining sites in the US, and they were chalcopyrite-rich (sample A) and conichalcite-rich (sample B) ore. Copper grades were 0.6% and 0.4% for the two samples, A and B, respectively. Leaching experiments were conducted by bottle roll tests for 24 hours, and various lixiviant systems were applied. Methanesulfonic acid (MSA) and glycine were used as alternative lixiviants to sulfuric acid. Oxidants including ferric ion and hydrogen peroxide were tested. The results showed the copper extraction of sample A increased after adding 1 g/L ferric ion in sulfuric acid and MSA solution, from 20% to 36%, but further increase was not observed with higher ferric ion concentration. The copper recovery increased significantly with H2O2 concentration, and over 80% copper recovery was obtained with 10% H2O2. For sample B, the copper dissolution kinetics were relatively fast and reached the maximum value in five hours. Around 60% copper were extracted in sulfuric acid and MSA solution. Copper recovery slightly increased after adding ferric ion and H2O2. Glycine is a weaker lixiviant for both samples, the copper extractions were 36% and 4% respectively. INTRODUCTION Chalcopyrite is the most abundant copper sulfide mineral on earth, and it is one of the most refractory copper minerals regarding chemical processing. The declining copper grade and depletion of copper oxide deposits stimulate the development of hydrometallurgical process to extract copper from chalcopyrite. The dissolution of chalcopyrite by ferric ion is normally illustrated as Equation (1) and (2) (Dutrizac & MacDonald, 1974): CuFeS2 + 4Fe3+ → Cu2+ + 5Fe2+ + 2S0 (1) CuFeS2 + 4Fe3+ + 3O2 + 2H2O → Cu2+ + 5Fe2+ + 2H2SO4 (2) However, slow kinetics are usually observed from chalcopyrite leaching at ambient temperature and pressure. Researchers attribute the slow kinetics to passivation during chalcopyrite dissolution, and different passivation products are also proposed (Klauber, 2008). In recent years, many efforts have made to develop new methods to extract copper from chalcopyrite, such as utilizing bacteria or stronger oxidant (Zhao et al., 2015; Ruiz-Sánchez & Lapidus, 2017).

Jan 1, 2019

By Weng Fu, James Vaughan, Stefan Lakemond

Uranium bearing copper sulphide flotation concentrates produced from iron oxide copper gold uranium (IOCG–U) ore contains radionuclides such as 238U, 230Th, 210Pb, 226Ra, 210Po, which have the potential to reduce their marketability, thus posing a challenge to the industry. Thus, a two–stage leach process has been proposed in this study. In first stage, a sulphuric acid leach process effectively dissolve most of the 238U and 230Th into solution, but other radionulclides (mainly 210Pb, 226Ra and 210Po) remain associated with copper sulphide minerals owing to their low solubilities in sulphuric acid solution. In the second leaching stage, the use of methanesulfonic acid (MSA, CH3SO3H) is investigated to selectively dissolve the 210Pb, 226Ra and 210Po from the residue of the first stage. The results indicate that 96% of 238U, 87% of 230Th, 90% of 210Pb, 86% of 226Ra and 17% of 210Po are dissolved using 3 mol/L MSA solution at 90°C for 3 hours, which represents a dramatic decrease in the radioactivity of the copper concentrate. INTRODUCTION Australia is host to one of the largest iron oxide copper–gold–uranium (IOCG–U) deposits in the world. Most of the value in these deposits is associated with copper. In mineral processing, the gangue minerals are separated from copper sulphide minerals that report to a copper flotation concentrate. However, due to the strong association of uranium with copper minerals and hematite, even clean copper concentrates can contain significant amounts of uranium (238U) and its radioactive decay elements, of which thorium (230Th), radium (226Ra), lead (210Pb), and polonium (210Po) are the long life radionuclides. These hazardous radionuclides negatively affect the marketability of the copper concentrates. Customer copper smelters in China, Japan and Europe may consider the radionuclides penalty elements or may not be able to process the feed. Therefore, there is a strong motivation to remove radionuclides from copper concentrates at the mine site before shipping to custom smelters in global market. Hydrometallurgical leaching has been widely employed to remove radionuclides from different kinds of minerals such as copper concentrates (Ragozzini & Sparrow, 1987), zircon concentrates (Aral, Sparrow, McDonald, & Norgate, 2007), and coal ash (Lei, Qi, Sun, Xu, & Wang, 2014). Leaching using sulphuric acid (H2SO4) solutions is the most widely used process for the extraction of uranium from uranium ores due to the relatively low cost and wide availability of the acid (Bhargava et al., 2015; Gilligan & Nikoloski, 2015). The leach process involves treating ground ore slurry with sulphuric acid at elevated temperatures (typically 60–90 °C) under oxidising conditions in order to convert the uranium in the minerals 2+ from the relatively insoluble tetravalent form (UO2) into water–soluble hexavalent state (UO2), which then complexes with SO42- and forms UO2(SO4)22- in solution. The uranium oxidation is generally carried out in the presence of ferric ion (Fe3+), regardless of the reagent and oxidant used. The most commonly used oxidants for uranium include sodium chlorate, pyrolusite and oxygen (Ring, 1980). These oxidants act indirectly by converting ferrous sulphate, formed by the oxidation reaction of UO2 in slurries, into ferric sulphate. The presence of Fe–containing gangue minerals such as hematite in the ore usually provides sufficient Fe required for the oxidation of UO2. After sulphuric acid leaching, the locked thorium (230Th), radium (226Ra), lead (210Pb), and polonium (210Po) elements are chemically liberated from hematite and uranium mineral grains (Ciobanu, Wade, Cook, Schmidt Mumm, & Giles, 2013). However, the extraction rate of radium (226Ra), lead (210Pb), and polonium (210Po) in sulphate solution is very low due to the limited solubilities of (Ra, Pb, Po)SO4 (Bagnall & Freeman, 1956; Liu & Papangelakis, 2006; Nikitin & Tolmachev, 1933).

Jan 1, 2019

By P. Dyas, H. Zouitt, D. M. Smith

"Falconbridge Copper's Lac Shortt gold mine is located in northern Quebec approximately 300 km northeast of Val D'Or and 100 km west of Chibougamau (Pig. 1). Engineering for the mill commenced in early 1983 with a feasibility study. The plant was commissioned in the fall of 1984 at a capital cost of approximately $12 million. Design capacity was 750 tpd which was increased in the fall of 1985 to the current level of 1200 tpd.The ore at Lac Shortt is free milling, grading an average of 5.5 g/t gold which is finely disseminated throughout the host rock. Pyrite at 3 to 5% by volume and traces of copper mineralization are also present.Some of the latest gold processing techniques known at the time of design were incorporated into the mill. These include carbon-in-pulp, pressure stripping, electrowinning of pregnant solution and induction furnace refining. The plant also features several innovations such as a unique interstage carbon retention screen in the CIP circuit and the outdoor location of the cyanidation feed thickener, mill solution tank and reagent storage silos despite -40° Celsius winter temperatures.This paper describes the current mill process and discusses some of the problems encountered during the first two years of the plant's operation. CRUSHINGThe Lac Shortt surface crushing facilities are located in a separate building, isolated from the wet processing circuits for dust and noise control reasons. The crushing plant equipment was originally utilized at the Manibridge operation in northern Manitoba where it had been designed to operate at 135 tph. However, at Lac Shortt a rate of only 80 tph has been achievable to date, mainly due to the hardness and frequently slabby breakage characteristics of the ore. Therefore, in order to meet fine ore requirements at the current mill throughput of 1200 tpd, the crushing circuit is run seven days a week. 24 hours a day. Availability has been averaging 65%."

Jan 1, 1987

By Andrea McGlynn

Iron Ore Company of Canada, Labrador City 2011?Canada's largest iron ore producer, leading global supplier of iron ore pellets and concentrates ?Rio Tinto (58.7%), Mitsubishi Corporation (26.2%), Labrador Iron Ore Royalty Income Fund (15.1%)

May 1, 2011

By E. S. Moore

"The Centre of the silver-producing section of the Gowganda area lies about 55 miles northwest of Cobalt, and the village of Gowganda is 71 miles by road from New Liskeard. The geological similarities of the Gowganda and Cobalt areas led prospectors westward from the rich Cobalt field, first to Elk Lake and then on to Gowganda, where mineralization was found in 1907. A year later many showings were found, and rich hand-picked ore was shipped. Most of the ore has come, however, from two mines, both of which are still operating; the Miller Lake-O'Brien, which was purchased by Siscoe Metals of Ontario Ltd. in 1945, and the Castle-Trethewey. The annual production of these two mines runs over one and one-half million ounces of silver and considerable cobalt. The total production of the camp has reached about 32,000,000 ounces of silver and a large amount of cobalt, the total not recorded.General GeologyThe general geology of Gowganda is in many respects much like that of Cobalt. There are areas of Keewatin basic and acid Javas mixed with tuffs and basic intrusions. These rocks are deformed and partly altered to schists, and have been intruded by some Haileyburian basic and ultra-basic rocks and by Algoman granite. These were followed by a large number of porphyritic Matachewan quartz diabase dykes. After a period of extensive erosion the Huronian sediments were deposited on a pene-planed surface over all the older rocks; these sediments include large quantities of conglomerate (partly tillite), quartzite, and greywacke. The Keweenawan rocks include the Nipissing quartz diabase sill, later quartz diabase dykes, and one long olivine diabase dyke, the latest Precambrian rock. The area has been extensively glaciated.Structural FeaturesThere has been little folding in the area since the Algoman batholiths were intruded, and the Huronian sediments lie nearly flat, with dips of 10, 15, or rarely 25 degrees. The Matachewan dykes show a remarkably uniform, nearly north strike, indicative of east-west tension when they were intruded. On the other hand, the dykes later than the sill strike nearly east, tangentially to the northeasterly and northwesterly strikes of the Miller Lake basin."

Jan 1, 1949

By J. A. Meech, R. J. Tucker

"A dynamic computer model has been developed to simulate the operation of ore crushing plants. The model was created in a general form to allow imitation of a wide variety of secondary crushing circuits with only minor program modifications. The system can be run on either a microcomputer or a large time-sharing main frame computer as required.The size reduction and separation characteristics of crushers and screens are based on standard manufacturers' design and performance data. These calculations are isolated within various subroutines to facilitate tailoring of the model to emulate any particular plant of interest. Input and output data are presented in a variety of formats. Crusher, screen and conveyor amperages and surge bin levels can be presented in a tabular form along with appropriate alarms arising from improper circuit operation or process interruptions. Graphical representation of the circuit together with strip chart data output are features of the system when operated in a microcomputer environment.The program is currently being used at Queen's University as a teaching aid to demonstrate plant operating characteristics, control strategies and design concepts. The acceptance of, and reaction to the program at this level indicates a good potential for it to provide a valuable tool for operator training."

Jan 1, 1985

By E. Pribonic

Failure of a mine material hoist can cause injuries, fatalities and significant infrastructure damage, along with an associated loss of production. Principal causes of hoist accidents are overwind and underwind. Past and present means of arresting hoisting equipment are marginally effective and utilize destructive systems that are not reusable following an arrest. The use of permanent magnet eddy current arrestor technology is proposed; the history and fundamental science of the technology are presented, followed by real world examples and calculations of performance for failsafe, friction-free, instantly reusable eddy current arrestors as applied to stopping a 30-ton ore skip traveling at 16 metres per second. A comparison of existing arrestor types with the eddy current arrestor is included and limitations of the ECA are also discussed.

Jan 1, 2008

By Manqiu Xu, Andrew Lee, Frederick D. Ford, Cara Wercholaz

"Platinum-group minerals (PGM) typically occur in such low concentrations that quantitative mineralogical evaluation is difficult or impossible. The FEI MLA system used by Vale Base Metals Technology Development has been successfully employed to produce large PGM data sets that are statistically robust. The MLA Sparse Phase Liberation mapping routine produces false colored images that accurately document mineral textures, including intergrowths between various platinum group minerals and between PGMs and other tellurides and sulfides. MLA PGM search results can be used in conjunction with mineral chemistry to calculate platinumgroup element distribution to minerals and the MLA PGM images can be used to produce model grade-recovery curves.INTRODUCTIONThe platinum-group minerals (PGM) found in Sudbury area deposits have been extensively catalogued and reviewed by many authors including, but not limited to: Farrow and Lightfoot (2002), Cabri and Laflamme (1984; 1976) and Cabri (1981). The PGM list currently used has 12 minerals summarized in Table 1. As noted by Farrow and Lightfoot (2002), platinum-group minerals in Sudbury are dominated by tellurides, bismuth-tellurides and arsenides, with an absence of platinum-group element (PGE) sulphides or ferro-platinum alloys such as tetraferroplatinum - PtFe."

Jan 1, 2011

By M. M. K. McCrank

"PRACTICAL SAMPLING TECHNIQUESIt is important to achieve reliability when sampling heterogeneous materials where there is a difference in composition, and non random distribution of the constituent particles. Throughout the design, construction and installation of sampling systems it must be borne in mind that the sampling point must be capable of:-allowing each particle in the stream an equal opportunity to be sampled.-accepting and collecting as large a volume or mass of material as necessary to satisfy the requirements of particle counting statistics.-establishing a sampling plan so that the sample is representative of the whole to a defined standard of accuracy.Design ConsiderationsFactors that may influence the design of the sample point include:-the mass, or volume flow rate of the material being sampled-the size and shape of the material or flowing stream-the physical condition of the material being sampled (i.e. temperature, wetness, size consist, density).-the chemical composition of the material being sampled -the location of the sample point and the space available for installation, extraction, reduction where necessary, secondary sampling, and return of the sample rejects downstream.-whether the process to be sampled is in an existing plant or one yet to be designed and built.-ease of access for servicing and maintaining the equipment.-whether the sampled material must be collected continuously or intermittently.-whether an existing sampling method is likely to be adequate or whether a new technique has to be developed."

Jan 1, 1989

By E. C. Grunsky, B. W. Smee

"The development of low-cost, rapid multielement analytical techniques has generated large geochemical databases in many exploration programs. When a sampling program consists of several thousand samples, the resulting data matrix is enormous and effective interpretation using all of the elements individually becomes burdensome. However, the application of multivariate statistical techniques can extract geochemical patterns related to the underlying geology, weathering, alteration and mineralization. Imaging the results over topography enhances the interpretation of these patterns. Examples of this approach are shown from mineral exploration programs in Canada and Mexico. IntroductionThere has been a dramatic change in the effectiveness of using geochemical survey data in the past ten years. This is mostly due to:• lower cost of geochemical analysis;• lower detection limits;• new methods of multi-element analysis;• a marked decrease in the turnaround time;and• the intelligent use of computers in presenting geochemical data.Geochemical surveys commonly have two objectives: locating abnormal concentrations of ore-forming or pathfinder elements and characterizing the underlying host lithologies. Geochemical surveys often employ a wide range of sample media that may typically include whole rock lithogeochemistry, various soil horizons, till and basal till sampling, stream sediments, lake sediments, and various forms of weathered regolith. Each of these sample media will exhibit a unique element distribution that must be factored in the interpretation phase of a geochemical survey study. This can become a cumbersome process if univariate data handling methods are employed."

Jan 1, 2003

By Stuart Elliot

Brownfield project portfolios are notoriously hard to manage. Day to day there is a constant stream of changes and challenges within projects and across the whole program. When the budget year is over, we?re often left wondering: did the facilities get what they really needed? Did we get value for the capital that was spent? Did we get all the project control and process improvement that we paid for? Great work has been done over the years by the Project Management Institute, Construction Industry Institute and Independent Project Analysis to identify what leads to project success, develop project delivery systems and equip project leaders to perform better. But is attention to individual projects all we need when the job is to deliver a portfolio of many projects? Let?s work with an analogy for a moment, and say a project is like a car, and a project manager the driver. Why can?t all the projects in the portfolio get home in time for dinner? The answer, of course, is that the commute home is about traffic, not just about cars. The road, the signals and the actions of other drivers affect us in our individual cars. Optimizing traffic flow is not about managing individual cars, it is about creating the conditions that allow all traffic to move as smoothly as possible. When we?re stuck in traffic, it doesn?t really matter that we are skilled drivers who know our exact location and our engine?s vital signs. Success with a brownfield portfolio requires more than the equivalent of driver training and a good GPS in every vehicle. Managing the annual budget requires more than tight management of each project. This is not a suggestion to abandon project management in the brownfield multi-projects world; the idea is to find and apply the right tools for delivering a portfolio. Remember, we want confidence in 3 areas: 1. that the facility is getting what it really needs, when it needs it 2. that we are getting value for money invested in facility modifications and improvements, and 3. that our controls are adding value by guiding our improvement What are those portfolio tools? The job they have to do is distinct from project-level thinking: ? Create a clear and balanced business pull for project ideas ? Maintain a respectable plan for fiscal, resource and business control ? Organize the work into a steady flow ? Manage the nature and timing of value-driven project substitutions and priority changes ? Focus on overall business value added and best use of resources ? Repurpose the projects organization into being the way the facility gets improved

Nov 1, 2011