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By D. A. Rhys

"The Red Bluff porphyry is a tabular 2 km long north-west trending Early Jurassic quartz diorite to monzodiorite body that intrudes a folded Triassic greywacke sequence in the lskut River area, northwestern British Columbia. The porphyry is 500 m to 800 m northeast of the Snip orebody, which is a southwest-dipping shear-vein, termed the Twin zone that contains approximately 35 tonnes of gold.The intrusion associated with the mineralization is characterized by 0.3 cm to 4 cm phenocrysts of K-feldspar in a mediumgrained plagioclase porphyritic matrix. It is overprinted by pervasive sericite + quartz ± K-feldspar ± biotite (potassic) alteration characterized by intense stockworking of quartz veins containing magnetite--hematite bands. This assemblage is cut successively by quartz veins with minor iron-oxides and pyrite, and by younger pyrite veins with phyllic envelopes. The system is gold-rich but copper-poor, with typical grades between 0.25 g/t and 0.6 g/t Au, and 0.1% and 0.2% Cu. All styles of alteration and veining have similar abundances of these metals. Where southwest- and north-east dipping shear zones are developed in the porphyry, veins of all types are sheeted and foliation parallel. These sheeted zones are interpreted to be syntectonic. Asymmetric phenocrysts, folded veins and oblique foliations developed in the 130 haulageway of the Snip mine imply oblique normally-directed shear on the southwest-dipping foliation.The adjacent Twin zone is a high-grade auriferous shear-vein system that is internally banded with: (1) carbonate-chlorite-biotite veins, with textures indicating formation at least partially by wallrock replacement, and (2) dilatant quartz-sulphide veins. Veins commonly have potassic alteration envelopes that contain biotite ± calcite ± K-feldspar. The zone is highly deformed and schistose, with numerous kinematic indicators including shear bands, asymmetric folds, rotated porphyroclasts and oblique foliations that indicate a normally-directed shear sense which is parallel to that indicated by fabrics within the porphyry.Precious and base metal veins within 2 km or 3 km of the Red Bluff porphyry are zoned. Veins and shear-veins proximal to the intrusion, such as the Twin zone, are typically enriched in gold, copper and molybdenum, and have potassic alteration envelopes dominated by biotite. Distal veins usually contain relatively abundant zinc and lead and have sericitic alteration envelopes. Structures of both types have an Early Jurassic galena Pb-Pb isotope signature.The similarities in structural fabrics and alteration histories in both the Twin zone and the porphyry, the zoning of the vein systems in the area, and the apparently concordant Early Jurassic zircon U-Pb age from the porphyry and galena Pb-Pb dates from the Twin zone and surrounding vein systems suggest that intrusion, semi-brittle deformation and a large mineralizing hydrothermal system were closely related temporally and genetically."

Jan 1, 1995

By L. H. Shang

The 319 Al-Si alloy is one of the most prominently used aluminium-based alloys in motor vehicle and engine applications, Microporosity present in 319 alloy castings reduces the load bearing capacity of the castings, The quantitative prediction of microporosity levels in Al-Si castings has been a subject of much interest for several years. In this research a new criteria function, tf 1,98 R13° (tf: local solidification time, R: cooling rate) was developed by multiple regression analyses, correlating thermal data from simulation studies to experimentally obtained microporosity values. This new criteria function gives a general prediction of microporosity in 319 Al-Si castings.

Jan 1, 2005

By A. Vien, B. C. Flintoff, R. P. Edwards

"A major thrust in industrial automation over the past few years has been the exploration and incorporation of higher level (supervisory and optimizing) control strategies aimed at more fully exploiting the existing control system infrastructure. There is little doubt that this is worthwhile pursuit, however, one must not lose sight of the maintenance and development requirements of the basic control system. Statistics on loop performance indicate that this too is an area of considerable potential. In this paper the authors look at some of the less elegant, but arguably equally important issues in mineral processing plant control. The focus is on controller structures, loop tuning, sampling, filtering, and some of the other principal components of the regulatory control foundations. In many cases significant improvements in control performance can be achieved by getting back to the basics.IntroductionEvery modem concentrator has a state-of-the-art computer control system in place. Several of these are contemplating installing, or have installed, advanced control systems, such as expert systems, but the foundation of their control system remains the PI controller. Although the authors are not aware of any survey or published information for the mineral processing industry, it is reasonable to assume that it would be similar to the pulp and paper industry. ""The average [pulp] mill has some 2000 control loops of which 97% use PI control. This means that PID, dead time compensation, adaptive controllers, specialized algorithms, ... , constitute only 3% of the installed base."" (Bialkowski [1992]).Bialkowski [1992] also stated that ""If you have been keeping score, only 20% of the loops surveyed actually decrease variability in automatic over manual mode of operation, in the short term."" He attributed the problems to: poor tuning (30% of all loops), control valve problems (30% of all loops) and process problems (20% of all loops). There appear to be a serious need to go back to basics and review the existing control system."

Jan 1, 1998

By V. G. c Papangelakis, M. Huang

A conductivity cell, developed previously, was employed in an effort to investigate the inter-relation between electrical conductivity and acidity of sulphuric acid - metal sulphate solutions at high temperatures. The measured solutions include the H2SO4-H2O, MgSO4-H2O, H2SO4-MgSO4-H2O, H2SO4-MgSO4-Al2(SO4)3-H2O solutions. All solutions reported in this paper were measured from 15 to 250 °C at equilibrium vapour pressure. The maximum measured concentrations of H2SO4, MgSO4 and Al2(SO4)3 were 0.45 m, 0.30 m and 0.10 m, respectively. It was found that, from 15 to 250°C, there is a linear relationship between H2SO4 concentration and electrical conductivities for acid concentration up to 0.45 m. At 250 °C and constant H2SO4 concentration, the solution conductivity drops with the increase of MgSO4 concentration. Lt is suggested that this drop is caused by a decrease in the concentration of H. Finally, an empirical model was developed based on the available measurements. This model has been tested against real laterite leach solutions where sulphuric acid and metal sulphates are dominant electrolytes. The average difference between the estimate acid concentration from this model and the one from titration was less than 5%.

Jan 1, 2004

By J. Flemming, R. O. Burt

"The Tanco pegmatite is located in the Bird River greenstone belt of southeastern Manitoba approximately 160 km northeast of Winnipeg (Figure 1). This pegmatite body was discovered in 1929 and subsequently attempts were made to exploit it for tin by Jack Nutt Mines Ltd. and later in the middle 1950's by Montgary Oil Ltd., who extensively developed but did not produce from, its lithium deposits. In 1966 systematic investigation of the pegmatite as a potential source of tantalum led to the founding of Tantalum Mining Corporation of Canada Ltd. (TANGO) in 1967 and production of tantalum concentrates from the Bernie Lake mine commenced in 1969. Tanco is currently jointly owned by Hudson Bay Mining and Smelting Co., Cabot Beryl co Inc. of Boston, and the Province of Manitoba. (Williams and others 1978, Burt 1979, Burt and others 1982), continued until the end of 1982, when, due to falling demand and prices, operations were suspended.During the 1970's Tanco had investigated the potential of the lithium orebody; carrying our research into both the concentration of the ore and into the production of lithium chemicals. However lithium chemicals were in an over-supply situation, due in part to the production from Chilean brine deposits (Buckley, 1983), and Tanco' s own plans were put into abeyance. The potential alternative market, the direct use of concentrates in the glass and ceramics industry, did not at the time justify the cost of constructing a new plant."

Jan 1, 1986

By John Starkey

"During the period June 2007 to March 2007, John Starkey of Starkey & Associates (Starkey) worked in Russia for High River Gold, supervising the engineering design work that was being done at the IRGIREDMET Research Institute, in Irkutsk Russia. The work entailed moving the Newmont No. 4 mill from Elko, Nevada to Berezitovy, a mine site north and west of the city of Skovorodino, in the Amur Region of Siberia. This was a grass roots project and required construction of all phases of the infrastructure and process facilities that are associated with a 5000 t/d open pit mine and CIP mill.During the course of this engineering design exercise, many aspects of doing business in Russia were encountered, with regard to laws, norms, and business practices. This paper discusses many of these findings. Also by living in Irkutsk, many observations on Russian life and social customs were made and these merit discussion from a general interest point of view.Prior to going to Russia, another engineering and ore testing firm (TOMS) had approached Starkey to find out if Starkey could assist them in upgrading their SAG ore testing procedures to Western standards in order to offer their clients turnkey projects, that included reliable SAG and AG grinding. TOMS was aware that Starkey had invented the SPI test but did not know that the SAGDesign test had by then been fully developed and was being offered commercially as the most accurate way in the world to design new grinding mills. They were also unaware that this new testing method had been patented by Outokumpu (now Outotec) and that this method allowed them access to a design method, through Starkey, that would lead to a manufacturer’s guarantee (by Outotec) of throughput and grind for any new semi-autogenous or autogenous grinding circuit, with or without ball mills.When Starkey started working at IRGIREDMET in June 2005, they also made a request to add a design method for SAG mills that would be considered acceptable to Western clients. From these requests, presentations were made in Russian to both institutes and each decided to join the SAGDesign Consulting Group as satellite members and buy a SAGDesign test mill to use with their Bond Ball Mill Work Index mills, to provide SAGDesign testing services. To complete the service, contracts have been put in place for Starkey to use these results to design new grinding equipment and to train engineers at TOMS and IRGIREDMET how to do this work.Starkey also undertook to train engineers at both labs to go into the field and to take the samples for SAGDesign testing programs. It is here where the SAGDesign testing service upgrades other grinding test programs because the samples to be used for design are professionally chosen, and the results will be much more likely to produce a satisfactory design. Starkey is a mining engineer and is uniquely qualified to do this task. This and the SAGDesign test are the key components that lead Outotec to offer a performance guarantee for mills designed by Starkey."

Jan 1, 2008

By Bradford C. Wesstrom, Ricardo Parra

The Freeport McMoRan El Paso Refinery uses co-generation to produce some of its electricity and all of its steam. This paper will cover the operation of the co-generation plant natural gas turbine at a fixed RPM for blade longevity and energy output. The by-product heat from the turbine passes through boilers with additional heat from a duct burner to produce steam for the Tank House and auxiliary operations. The steam demand varies dramatically throughout the day based on unloading activities in the Tank House. The use of an automated steam control system within the El Paso Refinery will help stabilize line pressure by incrementally controlling steam consumption based on electrolyte temperature. This will minimize steam line pressure fluctuations. INTRODUCTION In the mid 1920’s the Nichols Copper Company of Laurel Hill, New York recognized the need for a modern copper refining facility in the southwest. Due to the many railroad heads, affordable power and abundant labor supply, and the close proximity to regional copper smelters in Mexico, Arizona, and New Mexico, El Paso became the logical location. In December 1928, ground was broken for the joint venture refinery between the Nichols Copper Company, Phelps Dodge, and the Calumet and Arizona Mining Company. In September 1930, Nichols Copper Company became a part of Phelps Dodge Corporation after a stock exchange. In July 1938, Nichols Division officially became Phelps Dodge Refining Corporation. In March 2007, Freeport McMoRan Copper & Gold acquired Phelps Dodge. Energy costs (electrical and thermal) are critically important in the viability of modern copper electrorefineries. The El Paso Refinery produces electricity and steam through its cogeneration system. The El Paso cogeneration facility is a natural gas, 15-megawatt facility containing five turbine generators and associated waste heat recovery boilers. The facility is divided into two phases. Phase I consists of two Allison 2.2-megawatt turbine generators. Phase II consists of three Solar Taurus 3.5-megawatt turbine generators. Presently three units in Phase II are operated. The Phase I units were purchased and installed in 1986 and the Phase II units in 1992 (Solar 1991). The facility operated at full capacity until 2003 when steam demand was significantly reduced due to decrease in cathode production and closure of the copper sulfate and precious metal operations. Phase I units were taken out of service and put on care and maintenance status.

Jan 1, 2019

By G Zahary

THE most acceptable approacl1 to analyzing rock behaviour, at the present time, is based on the application of principles of mechanics and strength of materials. Analyses have been made in which the criterion of failure is based on maximum stress (1) and on Mohr's rupture theory (2). If such analyses are to be carried out, the mechanical properties of the rock must be known within acceptable limits. Although an adequate correlation of laboratory test results with field conditions has not been established, test results have been published (3) on the basis of their comparative value. That is, test results may be useful for comparing the behaviour of different rocks under similar loading conditions or of a particular rock under different loading conditions. This study aims at establishing some of the mechanical properties of an andesite rock by testing specimens cut _from diamond drill core. Drill core (EX) was provided from run-of-mine drilling by New Dickenson Mines Ltd. and Campbell Red Lake Mines Ltd.

Jan 1, 1963

By W. Dietzel

Fracture mechanics based techniques are used to gain insight into the phenomenon of stress corrosion cracking (SCC) and to develop guidance for avoiding or controlling SCC. From constant extension rate experiments under rising load or rising displacement conditions the susceptibility of high strength steels, aluminum, magnesium and titanium alloys to SCC and hydrogen embrittlement can be assessed. Such tests on pre-cracked specimens are also well suited for studying the mechanisms leading to SCC by employing appropriate models for the degradation of metallic materials which take into account the uptake of atomic hydrogen from the corrosive environment. Measurements of crack growth resistance curves using the crack tip opening displacement as fracture parameter can be compared with simulated R-curves obtained from modeling of the mechanism of hydrogen embrittlement. The materials investigated are a high strength steel and a magnesium alloy both exposed to environmental conditions which fostered the uptake of hydrogen.

Jan 1, 2010

By W. Blum

Progress made in improving the creep resistance of Mg alloys is reviewed with the emphasis on microstructural interpretation. Experimental results on the increase of creep strain with time at constant stress a measured for limited times and strains are displayed in a transparent form as creep rate-strain diagrams from which the minimum creep rate stress is safely derived. In addition, data on the thermal stress component a derived from high-precision a-reduction tests are reported. Within a simple statistical dislocation model these data allow one to quantify the relation between dislocation velocity v and a . In combination with structure evolution laws this relation serves as a basis for modeling the creep rate. New alloys have distinctly higher creep resistance than AZ91 where precipitation hardening plays a minor role. This is due to hardening by intermetallic phases which may form a continuous skeleton along the grain boundaries (e.g. Ca-alloyed AZ91) and/or submicron-sized precipitates within the grains (MRI230D, Mg-Zn-Ca alloys).

Jan 1, 2006

By M. Grenon

"The presence, size, orientation, nature, and persistence of geological discontinuities dictate the behaviour of a rock mass. Block size, which is defined by discontinuity spacing, by the number of joint sets, and by the persistence of the discontinuities delineating potential blocks is an important indicator of the degree of fracturing of a rock mass. Consequently, block size is represented either explicitly or implicitly in all rock mass classification systems employed for analysis and design of surface and underground mining structures. Insitu block size distributions may provide a better means to describe the structural complexity of a rock mass. These are the distributions that would be derived if the in-situ rock mass was separated into its constitutive blocks, delineated by existing discontinuities, and each block measured. This paper presents the results of a field campaign at Louvicourt Mine aiming to characterize the rock mass using different methods for determining block size and block size distributions. IntroductionGeological structural data are used to provide input data for analysis and design methods for surface and underground structures. As the collection of structural data involves considerable investment of time and effort, it is sometimes overlooked, thus denying an important source of information for mine design. What is somewhat surprising, however, is that when structural data are available, they are not used to their full potential. Recent work has shown that data on block size have potential applications in different areas of rock engineering:• Blasting — Hudson (1993) has described the excavation process as the change of a preexisting natural block size distribution to the debris fragment size distribution (Fig. 1). Lizotte and Scoble (1994) have reviewed previous efforts on integrating site specific geological conditions into blast design. Grenon et al. (1997) provide a case study where in-situ block size distributions are compared to photogrammetric studies of blasted rock.• Rock mass classifications — Block size is used in the majority of rock mass classification systems either explicitly, as in the RMi classification system Palmstrøm (1995), or implicitly, such as in the NGI system, Barton et al. (1974)."

Jan 1, 1998

By Ryan Montpellier, Paul Hebert

"Prospecting the Future: Meeting Human Resources Challenges in Canada's Minerals and Metals Sector is a comprehensive sector study of the short- and long-term human resource issues and challenges facing the minerals and metals industry. The study's in-depth assessment of current and emerging human resource needs and gaps served as a foundation for the recommendations designed to maintain the strength of the minerals and metals sector well into the future. The study provides insight and identifies strategies relating to each of the following areas:•,An aging workforce•,Significant retirements on the horizon•,Human resources demand growth•,Supply challenge - education and training programs•,Under-representation of non-traditional groups•,Supply advantage - attractive features of mining•,Supply and demand gap"

Jan 1, 2007

By Marc C. Bétournay

Under the requirement to define the economic advantages of using hydrogen fuelcell vehicles, a broadscoped project was initiated to quantify the costs associated with operating fuelcell vehicles and diesel vehicles. While ventilation savings are clearly an advantage for the former, a complete and detailed analysis of this and other operational and capital cost elements was undertaken in order to provide the mining industry with factual information in considering the changeover from one technology to another. This article outlines the results of the investigations to date defining the costs/benefits associated with: capital purchases, operations (electrical/diesel, mine air heating fuel, ventilation, openings, surface and underground infrastructure, maintenance, labour, etc.), delivery of energy, regulatory obligations, and mine production. Considerations are given to the type and size of a mining operation, the depth, and location in North America. Significant ventilation power, equipment and infrastructure savings are possible with the application of fuelcells for shallower mine applications. At depth, where heat is an issue, there is a reduction in benefit. Specific qualifiers such as minimum air velocities, dust dilution, shaft and heating system velocity limits must be considered on an individual mine basis. While the capital cost for fuelcell mining equipment is currently higher than diesel versions, the high cost of fuelcells is anticipated to be reduced significantly in the near future with the intensification of manufacturing. In either case the operational savings would probably be sufficient to balance the supplementary capitalization costs. A comprehensive cost-benefit report will be issued in the near future.

May 1, 2003

By Laura Mottola

This paper outlines a framework for ensuring the success of the implementation phase that follows research and development of new mining technologies and systems. It is based upon recent and past lessons learned that have demonstrated the critical challenges to effective technology transfer, which frequently receive inadequate attention within the culture of the mining business. The paper focuses on mining automation implementation challenges and then outlines a Roadmap which is proposed as an integrated framework to deal with the key aspects of people, process and technology. This framework is built upon: assembly of a Strategic Team to develop a Roadmap; fully understanding the business requirements of the technology initiative; defining Key Performance Indicators in a Balanced Score Card; performing a Stakeholder Analysis to identify the affected groups; and finally developing a master Project Plan to execute the Roadmap.

Oct 1, 2009

By Phil Thwaites

"The mining industry uses many types of mineral and metallurgical plants to produce saleable product from ore mined. Plant design history has left current operations with a mixture of manual operation and various forms of automated process controls. Consequently, we typically see high variability in the continuous operations together with a shortfall in the attainment of full capacity, or higher utilization of consumables.At a level of best practice, “Operational Performance Excellence” focuses on process control, using automation and control systems to deliver process optimization. This more sophisticated delivery is a great deal more difficult than the first stage of equipment selection / installation. It includes the appropriate selection of the right instrumentation, control system, key process knowledge, individuals with a solid control engineering background/experience, and the essential backing/ support of the operations management team together leading to higher value delivery. Robust solutions can be realized, considerably minimizing process variation, thus leading to process optimization. This approach results in an easier, efficient and safer process while providing considerable returns for the plant owners.How variable are your processes, and do you maintain optimized process performance with dedicated resources, modern instrumentation, ‘best practice’ control systems and performance monitoring tools? In this lecture, these questions and their possible answers are discussed.357"

Jan 1, 2013

By George H. Hope, Steve Ciccone

"The Red Dog Mine is both the largest known zinc reserve and the largest zinc producer in the world. The mine started in 1989, and by 1999 had increased production from approximately 300,000 tonnes per year (t/yr) of zinc concentrate to in excess of 900,000 t/yr. The VIP Mill Optimization Project further increased zinc concentrate production to 1.1M t/yr while improving both product quality and zinc recovery. The Mill Optimization project also addressed a number of issues related to risk reduction: power generation capacity, water treatment capacity and concentrate thickening. The project was faced with numerous challenges, the most daunting of which was the schedule. This US$105M project was executed, from conception to completion, inside of two years. Less than nine months elapsed from concept to delivery of materials and equipment to site. The project also faced a 100-day ice-free shipping window, the challenges of construction in an Arctic environment, and an extremely tight labour market for qualified craft personnel. These challenges were successfully addressed with several innovative approaches to project execution, including an Alliance contracting arrangement between the owner, engineer and contractor; full integration of the team; construction of modules in Anchorage; and fast-track engineering, procurement and construction.INTRODUCTIONThe Red Dog Mine, which began operations in 1989, is located above the Arctic Circle in Northwest Alaska, approximately 145 km north of Kotzebue (Figure 1). An 80-km road connects the mine site to the DeLong Mountain Transportation System (DMTS) port site. Red Dog is the largest known zinc deposit in the world, with known reserves totalling 94.5M tonnes, and is the largest zinc producer with a concentrate production rate of more than 1.1M t/yr.Open-pit mining is by typical drill, blast and load operation using moderately sized mining equipment. Ore is processed through conventional crushing, grinding, and flotation to produce separate lead and zinc concentrates. Filtered zinc and lead concentrates are trucked year-round to the DMTS port site, where they are stored in two A-frame buildings, 330 and 440 m long. A lightering barge system is used to transfer concentrate from the shallow water load-out to deep-sea vessels anchored approximately two miles offshore. Shipping is limited to a 100-day, ice-free window beginning in early July."

Jan 1, 2003

By Jean-Claude LeRoy, Herman Keller

"INTRODUCTIONEROCON's work is the reclamation of mine wastelands. It has had considerable experience in particular in the reclamation of gold mine tailings in the Canadian Shield since the latter part of the sixties when most gold mines were closing down.A typical example is the famous Hollinger Mine in Timmins which produced $566 million worth of metal from 1910 to 1968 and had left behind some 56 million tons of tailings covering about 1,000 acres which were reclaimed on very short order and are now lush meadows of agricultural quality.To date, practically all gold mine tailings have been reclaimed once and for all by establishing a permanent, self-sustaining and maintenance free vegetation cover.RECLAMATION & THE MINING TOWNSThe first appreciation of people in a mining community where the tailings have been revegetated will be noticing one day the elimination of dusty conditions that used to arise formerly on every dry and windy day. In that respect, EROCON encourages not only vegetating the tailings but also the immediate surroundings of the mills and plants themselves at active mines. The elimination of windborne dust will result in an appreciable decrease in maintenance costs of plant and machinery and more pleasant working conditions for all."

Jan 1, 1975

By S. Belair, V. Weigel

As a growing mining company, ERAMET is looking for new positions on the strategic metals market. In this context, the Gabonese Maboumine pyrochlore deposit is currently being studied for the recovery of niobium, tantalum, rare earth elements (REE), and uranium. This ore shows mineralogical and chemical characteristics that make it challenging to process by already known practices, from both technical and economic points of view. In this context, ERAMET has developed since 2008 an innovative hydrometallurgical process which has been successfully operated at a pilot plant scale. While the upstream part of the process aims to dissolve the valuable elements in sulphuric acid, the downstream part of the process aims to recover them separately in a marketable form. The focus here will be on the recovery of the REE. The ore deposit contains approximately 1.4% of REE including 87% of light REE and 13% of medium-heavy REE. The challenge in this process lies in the fact that the major elements in the matrix are iron and aluminum. An innovative process has been developed in order to recover all of the REE in these unfavourable conditions, described in this paper.

Jan 1, 2014

By M. Kerr, Petra Lampinen, Jinming Zhang, Petra Brodin, C. Hull, Nils-Johan Bolin, R. Asmatulu

"According to Darcy’s equation, the rate of dewatering varies as inverse square of the surface area of the particles to be dewatered and is proportional to the pressure drop across a filter cake. Thus, the difficulty in dewatering fine mineral concentrates can be overcome by using high-pressure filters. When treating ultrafine particles, however, it is often necessary to further dewater the filter cake using a thermal dryer. In the present work, novel dewatering aids that can reduce the pressure requirement have been developed. The reagents are designed to reduce surface tension, increase particle hydrophobicity and increase capillary radius, all at the same time. They were tested for dewatering mineral and coal concentrates in both laboratory and pilot-scale tests. The results show that the use of the novel dewatering aids can substantially reduce cake moistures and, at the same time, increase throughput. In this communication, the case history of using the reagents commercially at the Garpenberg concentrator is given. The use of the novel dewatering aids allowed the operators to use a vacuum filter to obtain desired cake moistures and obviate the need to use a thermal dryer.INTRODUCTIONDewatering is an integral part of mineral and coal processing operations, as it is necessary to remove water from concentrates (or clean coal) to minimize shipping costs, meet contract specifications, and recycle the process water. In general, the cost of dewatering increases with decreasing particle size, which can be attributed to the difficulty in removing the water trapped in the pores (or capillaries) formed between the particles constituting a filter cake.The various parameters affecting the process of dewatering, including the effect of particle size, can be understood in view of Darcy’s equation (Darcy, 1856):"

Jan 1, 2005

By R. A. Brown

RIGHT NOW the Canadian oil business is suffering from growing pains brought on by developments outside our borders. I would like, therefore, to place our industry in perspective for you in two ways. I would like first to describe it briefly and let you see it in relation to the world oil industry. Then I would like to bring it back and place it into perspective against a strictly Canadian background. Naturally, in such a discussion, it is necessary to use a certain amount of statistical material. I'll endeavour, however, to keep it to a minimum. Eleven years ago, before the discovery of Leduc, Alberta could boast of having 21,000,000 barrels of crude oil reserves. Five years ago we had 1,810,000,000 barrels. At year end, 1957, our remaining recoverable reserves totalled more than 3,000,000,000 barrels. In 1957, our potential production in Alberta reached an all-time high of 756,000 barrels a day. Unfortunately, our actual average daily production dropped from 393,000 barrels per day in 1956 to 376,000 barrels per day in 1957. And in 1958, to date, it has dropped sharply to around 300,000 barrels per day.

Jan 1, 1958