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By L. J. Heaslip, J. M. Toguri, T. R. Meadowcroft, R. L. Addinall

"""Pilot Plant Operations"" is a final-year core course given to the Metallurgy and Materials Science students at the University of Toronto. This course involves a laboratory study of an industrial project at an industrial site. Details of this program are discussed and reviewed after eight years of experience. IntroductionEducators in the field of Metallurgy and Materials Science have long agreed that ""hands-on"" experience is an important component in the education of metallurgical engineers. This philosophy is reflected in the undergraduate curricula of most metallurgical schools. The major problems encountered with laboratory-associated courses are the requirements for equipment, space and funds for both purchase and maintenance of equipment. For example, consider an exercise in crushing and grinding treatment in a mineral processing laboratory. Such operations require the handling of tons of material and often equipment of large size. The problems of storage of ore, methods of handling and maintenance of equipment are a few of the concerns facing the department. Considering that metallurgical departments at universities are, in general, relatively small, the support to purchase and maintain largescale equipment becomes an annual budgetary concern. In reality, universities today are not geared to operate mini-pilot plant equipment, either in terms of space or personnel.For the above reasons, in 1972an undergraduate core course called ""Pilot Plant Operations"" was introduced to the fourth year curriculum in Metallurgy and Materials Science at the University of Toronto. This course consists of I to 2 full weeks (8 hrs per day) of pilot plant laboratory study at an industrial site on a project of mutual interest with the industrial organization whose facility is being used. The first 5 years of the program were carried out at the pilot plant facility at the Ontario Research Foundation; Stelco's Research Centre in Burlington, Ontario, was used for the last 3 years. The nature of the projects undertaken during the 8-year period is shown in Table 1."

Jan 1, 1980

By Pathies Nawej Muteb, Tom Strombotne, Karl Leetmaa, Irma Gabric, Keith Darby

"Continuous control of the final grinding product size is important to optimize gold liberation for Gold Milling operations. At Meadowbank Mine an on-line Particle Size Monitor has been employed successfully to achieve the targeted final grind which leads to optimizing the gold recovery at maximum grinding circuit throughput. The live monitoring of the final product particle size leads to a maximum grinding circuit throughput every minute during the process. This paper discusses the optimal utilization of the Particle Size Monitor to assist the Mill operator to maximize the grinding circuit throughput as the milling conditions change due to variable ore processed at Meadowbank Mine. Also the paper includes the usage of the Particle Size Monitor to guarantee the final grind target at each instant of the process.IntroductionAgnico-Eagle is a Canadian-based company that Trades on the TSX & NYSE (AEM). It owns eight mines (8) operating in Nunavut, Quebec, Finland and Mexico and has more than 7,500 employees (Figure 1). 1.6 M ounces of gold were produced in 2015 and the annual average annual production from 2016 to 2018 is forecast to be approximately 1.53 million ounces of gold.The Meadowbank Mine is located in Nunavut, Canada (Figure 2). The mine opened in 2010 and from 2010 to 2014 a total of 1.8M oz of gold was produced. The milling rate is 4.2 Mt per year with an average mill throughput of 11,900 tpd or 496 tph. Average annual gold production over life of mine is expected to be 450,000 ounces. Meadowbank has 775 employees, of which 265 are Inuit or 36% of the total workforce. Estimated life of mine is 2010 to 2018. Gold production in 2015 was 381,804 oz. Meadowbank was Agnico-Eagle’s largest Gold producer in 2015."

Jan 1, 2017

By W. P. Tassie

"The location of Quintette Coal Limited's pit and geologic nature of the dedicated reserves combine to introduce a number of factors which can adversely affect waste dump stability. These factors include steep terrain, variable material type and particle size, and precipitation. This paper describes the solutions to related waste dump problems. A brief geotechnical review of the waste dumps is given and Quintette's operational strategies during periods of dump stability and instability are discussed. Despite best efforts, failures occasionally occur and discussion is included on Quintette's success at bringing failed dumps safely back into use. IntroductionQuintette Coal Limited (QCL) property is situated on the east slope of the Rocky Mountains near Tumbler Ridge, approximately 120 km southwest of Dawson Creek, British Columbia. This surface mine is located on mountainous terrain and is subject to climatic extremes of wind, precipitation and temperature.QCL has a current annual production of 4.75 million tonnes of metallurgical coal with a stripping ratio of 7: 1. This correctly implies the extraction of over 33 million bank cubic metres (BCM) of waste which is placed on numerous waste dumps at various locations adjacent to the pit.There are three active pits - Mesa, Wolverine, and Shikano (Fig. 1). Shikano is a newly developed pit located near the plant site. It is not subject to the unique dump management problems prevalent at the Mesa and Wolverine pits, therefore the Shikano waste dumps will not be discussed . The dumps for the Mesa and Wolverine pits, however, have been technically and operationally challenging since shortly after mining began in 1983. Their characteristics, associated site specifics and management, therefore, are the subject of this paper.Waste dump locations for the Mesa and Wolverine pits are shown in Figures 2 and 3 as is the relative waste distribution . Each sub-pit is connected to a principal waste dump in reasonable proximity and to an alternate dump should disposal of waste be necessary at that location. The waste dumps are constructed from the top elevations initially to coincide with subpit development. In the initial years (1-7) waste dump heights will be up to 250 m, then, as the mine matures (8-20 years), waste dump maximum heights will continuously decrease to coincide with lower bench elevations"

Jan 1, 1988

By Eric Bain Wasmund, Lance Christodoulou, Julio Jairo Carmona Franco, María Fernanda Castillo, Jose Concha

"A number of technologies are in practice for selectively removing coarse gold from conventional grinding circuits. These circuits are often designed so that the grinding mill output is size classified, with large (or high density) particles being removed before the tails are returned to the mill. Because of the high relative SG of gold, and the fact that some forms of gold such as free gold do not break apart during conventional grinding, coarse gold can accumulate in the circulating load, and eventually be lost.Eriez has developed a flotation cell that uses fluidized water to enhance flotation of coarse particles. More than 40 units have been sold in industrial minerals, and we are now exploring applications for the HydroFloat® in the gold industry.Mineros S.A currently produces approximately 120,000 oz of gold per year by gravity concentrating alluvial gold ore with a mean particle size of 330 microns, followed by further concentration using a Falcon separator. A 400 mm diameter pilot-scale HydroFloat® was added to the tails of the Falcon to test whether additional gold could be captured. Enrichments of 50-600 times and recoveries normally in excess of 95% were achieved. This allowed direct smelting of the gold concentrate. Metallurgical results and operating parameters such as water addition and power will be discussed during the presentation.This result opens the possibility that the HydroFloat® could be used directly in the grinding circuit, for removing coarse gold in the circulating load. This work also shows the possibility that the HydroFloat® can produce a throwaway tail, which will reduce the size of the circulating load stream and the grinding requirements of the circuit."

Jan 1, 2015

By P. H. Reynolds, S. Liaghat, A. Zarasvandi

"Darreh-Zerreshk and Ali-Abad are two relatively small porphyry copper-type deposits in Yazd Province in central Iran. They are located within the central Iranian volcano-plutonic belt, formed above the collisional convergent margin of the Iranian lithospheric plate from the late Eocene to the Miocene. This paper discusses the geochemical characteristics of the igneous rocks, and 40Ar/39Ar geochronology of plutons and alteration phases associated with the Darreh-Zerreshk and Ali-Abad deposits. The deposits are spatially associated with igneous complexes that consist of older and barren granites intruded by intermediate-composition granitoids, which are the carriers of Cu mineralization. The granites have relatively high content of Nb, Y, and K, a prominent negative Eu anomaly, and were probably derived from melting of, or contamination of mantle-derived magmas by, continental crust. Porphyritic diorites, quartz monzodiorites, and granodiorites show enrichment in light rare earth and large-ion lithophile elements, depletion in middle rare earth elements, and have no negative Eu anomaly. These intermediate-composition granitoids were derived from melting of the upper mantle or lower crust, and their differentiation was controlled partly by fractionation of hornblende. A pilot K/Ar whole-rock dating study suggests that the pre-ore granites were emplaced in the Oligocene. Dating by the 40Ar/39Ar method of nine samples of secondary biotite and sericitized rocks from drillcore within the mineralized and altered zones in both deposits yielded a well-defined age of ca. 16 Ma. This date is interpreted to be the time of hydrothermal alteration and of porphyry copper type mineralization in this part of Iran."

Jan 1, 2007

By N. W. Johnson

"Two analysis tools which have been applied to problems in industrial flotation processes are the application of kinetics and detailed mineralogical or liberation data, both on a size-by-size basis. This paper describes practical examples of the application of kineticsto examination of the entrainment recovery mechanism, the retardation of valuable minerals at the commencement of flotation sections and the resolution of problems related to valuable species with reduced rate constants at the end of sections. Examples of the usefulness of size-by-size liberation data for monthly composite samples of products from a concentrator are also described.IntroductionMuch of the published industrial flotation data on the behaviour of minerals in various size fractions have been obtained from specially conducted surveys with a duration of several hours. Such data are very valuable and provide a record of the behaviour of the entire flotation plant or sections during the interval of the survey. Some examples from the literature can be cited Cameron et al. (1971), Lynch et al. (1981), Frew (1982). Less attention has been given to the value of complementary sized data derived from compositing shift or daily inventory samples over an interval of one or several weeks with repetition of the procedure at the completion of each interval. Mineralogical point count data of the size fractions of such samples and data interpretation are rare in the literature.Kinetic data on the behaviour of valuable and gangue minerals in various size fractions have been reported often for flotation banks. In the experience 0 f the writer, there has been a tendency among operating metallurgists to ascribe problems in the flotation process to rate constant values for gangue minerals which were believed to be unsatisfactorily high. Less attention has been paid to the value for the rate constant for the valuable mineral over the length of a particular bank.Examples of the types of data which were mentioned previously have been obtained from the lead-zinc concentrator at Mount Isa Mines Limited. The various types of data have been collected to evaluate their worth in order to provide relevant information for both research and operational aspects of the plant."

Jan 1, 1987

By K. Najim, D. Hodouin

"The raw ores which are processed in mineral processing plants exhibit very strong variations of their physical and chemical properties. As a consequence, the performances of the comminution and separation processes vary greatly from time to time. Model-based control strategies improve the performance of the plant; however, they require some form of adaptation to cope with the variations of the are properties.This paper deals with the use of adaptive techniques for the control of mineral processes. It begins with a survey on adaptive control algorithms including parameters estimation aspects. Then several examples dealing with crushing, rod, ball, autogenous and semi-autogenous grinding, flotation , drying and calcination processes are reviewed.IntroductionThe operation of the various processes of mineral processing plants (crushing, grinding, flotation, dewatering, etc.) is generally controlled using empirically tuned regulators of constant structure, such as PID controllers. To improve the operation performance, mineral processors try to implement specifically designed controllers, i.e. controllers based on plant dynamic models. Most of the time, these techniques improve the control of the mineral processing installations. However, modelling is a complex procedure because of the problems of measurement and data management, specific to this industry, and because of the variations of the model parameters. In this context model-based control strategies do not always bring the expected improvements or are sometimes discarded and replaced by more conventional techniques .The sources of variation of the dynamic behaviour of mineral processing systems can be classified into three categories: (I) the inherent changes of the raw ore properties (composition, grindability, mineralogical texture, etc.); (2) the process tuning modifications (grinding media loads, number of hydrocyclones, slurry level in flotation cells, agitation speeds, etc.); (3) the feedrate variation of the ore, water, chemical reagents, etc. All these factors change the fundamental properties of the process dynamics such as the grinding or flotation rates and the residence time in the equipment. The simplified linear models which are used to describe the process dynamics are not able to track the complex behaviour of the mineral processing systems when the amplitude of the sources of variation are too large. The mismatch between the model and the plant behaviour is then frequently a cause of model-based controller failures."

Jan 1, 1992

By K. K. Murray, D. G. Gelderland

"The pressure oxidation autoclave at the Goldcorp’s Red Lake Gold Mines (RLGM) was commissioned in 1991. Since commissioning, the circuit has been well maintained and its capacity increased to mechanical and gaseous oxygen limitations. With advances in available technology, opportunities to produce more sulphide concentrate and a changing business environment, an optimization project has been initiated at RLGM. A multi-phase approach has been developed to optimize both the operations and economics of the circuit. This paper describes the history and future of the autoclave circuit at RLGM.AcknowledmentsWe would like to thank the operations and maintenance staff at Red Lake Gold Mines for their support and openness of mind to enact changes to enhance the operation. We would also like to acknowledge the members of the integrated team from Red Lake maintence, metallurgy, operations and corporate technical services that did the hard work to push past the status quo in order to advance productivity.OpportunityThe Red Lake Gold Mines (RLGM) pressure oxidation (POx) circuit has been in operation for over 25 years processing the high sulphide content gold bearing minerals. Increased sulphide concentrate production from improved flotation recovery and increasing gold sulphide association at depth has led to the POx circuit becoming a throughput bottleneck. The opportunity exists to process increased tonnages of sulphide concentrates and increase gold production. In order to realize this value, it will be necessary to increase the throughput capacity of the POx circuit.BackgroundThe POx autoclave at the RLGM, commissioned in 1991, was Canada’s first gold autoclave. It was installed to replace the two-stage fluid bed roaster that was built when the Campbell mine and mill were constructed in the late Forties. The circuit was originally designed to process 12.5 t/d sulphide sulphur in about 50 t/d of Campbell flotation concentrate. Following the merger of the Campbell and Red Lake Mines in 2006, the POx circuit started processing flotation concentrate from both Campbell and Red Lake Mills. In recent years, the circuit has been processing about 18 t/d sulphide sulphur in 75-85 t/d flotation concentrate."

Jan 1, 2017

Agenda ?Trends in Wireless Technology ?Success and Opportunities ?Improving plants efficiency ?Improving plants reliability ?Improving plants safety and security ?Wireless Ecosystem ?Lessons Learnt / Recommendations Why Wireless? ?Lower cost (no wiring cost) ?Flexibility (no wire) ?Standards-compliant wireless devices major factor enabling growth:?Standard WLAN (IEEE 802.11)?Wireless field I/Os (IEEE 802.11, ISA100.11 and WirelessHART) ??Wireless adoption will become a milestone that will rival the introduction of Fieldbus and the distributed control system (DCS) in its importance.? ARC Advisory Group

May 1, 2009

By J. Ling, L. Racine, P. Cousin, A. R. Laplante

"The problem of gold recovery by gravity from high density gangues is first discussed from a fundamental perspective. Three potential difficulties are presented: poor liberation and fine gold particle size, concentrate bed erosion by coarse dense particles, and slow percolation of gold particle through the high density gangue bed. Two case studies are presented to illustrate the impact of these three problems on circuit performance and the feasibility of gravity recovery. It is concluded that careful testing can determine the scope of the first problem and feed preparation can limit the extent of the second. The third problem is clearly the most serious and results in lower gravity recoverable gold recoveries than would be achieved with the same recovery effort on a low density gangue application.IntroductionSince the commercialisation of the Knelson Concentrator in 1980, gold gravity recovery has experienced a surge in interest, in Canada and the United States first, then Australia, Zimbabwe and Russia, and finally worldwide. Table I details number of units sold in various countries, which corresponds approximately to their importance as gold producers 1. Exceptions. such as the low rank of South Africa or the importance of Zimbabwe, despite the much higher gold throughput of the former, are generally the result of differences in the effectiveness of the local marketing strategies, as well as a reflection of the ""philosophy of recovery"" prevalent in the country.The impact of the Knelson has not been felt equally in all plants. Typically, a highly successful application falls into the following categories: (a) alluvial or hard rock recovery for which gravity is the sole recovery method, (b) hard-rock free gold milling with ores which have a very high gravity-recoverable gold (GRG) content, (c) low grade sulphide copper-gold ores which include flotation ahead of cyanidation and (d) free-milling gold ores ahead of Other applications can be successful, but are not as common. The ""explosion"" of centrifuge concentration, of which the Knelson is the most successful but by no means the sole model, has created a certain euphoria which can be summarized as ""gravity recovery will improve the profitability of gold milling, no matter what."" This presentation is about applications that are not so successful, or even downright unsuccessful. The rationale is not to down-play gold gravity recovery, but to set it in its rightful position: metallurgically, it is not appropriate all of the times; it can become inappropriate if poorly designed; and it can be metallurgically possible but economically unjustifiable. In this paper, this will be illustrated and explained rather than demonstrated, with the use of both industrial plant surveys and laboratory test work. Alternate gravity approaches will be suggested."

Jan 1, 1997

By R. Mohan Srivastava

"The goal of estimation is considered in the light of decision analysis. A simple example reveals the essential elements of decision-making in the face of uncertainty. A second example shows that these elements are also key features of many mining decisions. These two examples cause us to revive an old probabilistic notion that the goal of estimation should be to quantify what is unknown. The conditional probability distribution provides the complete statement of one's uncertainty. Once the conditional probability distribution has been established, one should retain as an estimate the value which minimizes some objective loss function. A third example shows how the ""best"" estimate depends on the chosen loss function. Current practice is almost exclusively based on the least squares method, which assumes a loss function which penalizes underestimation and overestimation equally. This is unfortunate not only because symmetry is an unrealistic assumption but also because mining offers a rare opportunity to state the loss function directly in terms of profitability. Both the theoretical framework and the practical tools exist to allow us to reconsider the conventional notion of the ""best"" estimate. IntroductionThis paper looks at estimation in the mining industry from the point-of-view of decision analysis. Virtually all decisions depend on estimates since few of the important parameters are ever known exactly. In this paper we will be referring mainly to the estimation of ore grades, though the approach discussed here is generally applicable to any decision in which relevant information is uncertain.In the first section we look at a very simple example of decision-making in the face of uncertainty. We will then tum to a mining example and see that the essential features of the simple example still pertain. From these two examples it will be clear that the decision analysis approach rests on two key concepts: the conditional probability distribution and the loss function. A third example demonstrates how different loss functions produce different ""best"" estimates from the same conditional probability distribution. In the final sections we willexamine the current practice of estimation in the mining industry. Though the tools for estimating the conditional probability distribution already exist, a change in the way we think about ""best"" estimates is needed. Very little attention is presently paid to the loss function even though it is readily available in many mining applications."

Jan 1, 1987

"Air Products approached LAC Minerals in 1987 to initiate trials with pure oxygen in the leach circuit at several LAC facilities in Canada. This paper gives an overview of oxygen use and covers specific operating data from the Doyon and Terrains Aurifères mills near Val D'Or in northwestern Quebec. LAC also uses oxygen at the Macassa mill in Kirkland Lake, Ontario.In addition to the LAC facilities, oxygen is currently in use for test purposes at the Holt McDermott mine in Kirkland Lake, Ontario and the Camflo mine near Val D'Or.There are two requirements for oxygen in the cyanide leach mill. Firstly, oxygen is required in the familiar gold dissolution reaction as follows:(1) 4 AU (s) + 8 NaCN (aq) + 02 (aq)+ 2H 20(aq) - 4NaAu(CN) 2(aq)+ 4Na OH(aq)Of the reagents on the left side of the equation, the availability of gold is fixed by the ore in question. Obviously, water is available in excess, 1eaving cyanide and oxygen as the limiting constituents in the process. Most mills operate with an excess of cyanide, which is fairly closely monitored. Dissolved oxygen levels, however, are not normally watched very closely and find their own level based on the temperature, the availability of compressed air and the ability of the ore to consume oxygen.Typical D.O. levels are in the 3-8 ppm range, however levels less than 1 ppm are not uncommon for refractory ores.With pure oxygen, dissolved oxygen levels as high as 30 ppm can be achieved. (Figure #1). This greatly accelerates the kinetics of the leach reaction and may also shift the reaction further towards completion thus increasing gold dissolution slightly."

Jan 1, 1990

By D. Bois, P. Keating, J. Lemieux, M. A. Vallée, M. Allard, R. S. Smith, L. Z. Cheng, M. Chouteau, K. Fountain

"A comparison of data from INPUT, GEOTEM, and MEGATEM airborne electromagnetic (AEM) systems over the Aldermac deposit, Québec, Canada, was undertaken to evaluate the relative ef¬ficiency of these systems for the detection of small, deep conductors. The Aldermac orebody was mined between 1933 and 1934 to a depth of 200 m. A deeper mineralized zone was discovered in 1987. The MEGATEMII system was used to acquire 90- and 30-Hz data over the deposit in 2003 as part of a research project. These MEGATEMII data were compared with data acquired by other AEM systems (GEOTEM and INPUT), and the results show that the MEGATEMII response is ten times larger than the other sys¬tems. For the dB/dt response, 30 Hz gives a better signal-to-noise ratio, whereas 90 Hz has a better signal-to-noise ratio on the B-field.The data were evaluated by numerical modeling. The deposit was best represented by a complex mod¬el, comprising two weakly conductive bodies to approximate the alteration halo, two deeper prisms repre¬senting known orebodies, and three bodies ranging in thickness from 3 to 6 m and in resistivity from 12 to 20 ohm·m, representing the chargeable overburden. This implies that the MEGATEMII system is able to see a small conductive body at more than 200 m depth in an area where the response is contaminated by conductive overburden."

Jan 1, 2009

By Balmer Neilly

We are regularly told that before making a new investment one should seek the advice of his banker. If we were to place the subject matter of this paper before bankers. other than those who have experience in our mining camps, their reply would probably be evasive. However, if for example: a mining company asks them for a loan and offers as security certain mining investments, they are, in most cases, explosively candid. The idea is preposterous, unless, under Section 88 of the Bank Act, the mining company is able to deposit with the bank, gold or silver bullion, to an amount sufficiently in excess of the loan, to provide for what the banker describes as a reasonable margin of safety in case of contingencies. In addition the directors of the mine personally must jointly and severally guarantee payment of the loan. With any of these conditions missing the banking atmosphere becomes chilly. The local manager explains that the general situation, and particularly European conditions, are so unsettled that head office has warned him that his discretionary powers must not be exceeded under any circumstances.

Jan 1, 1924

By E. W. Thorton

"This paper is intended to show that grinding media can effect flotation results, and in some instances the results are vastly different. I do not suggest that autogenous grinding is beneficial in the separation of all complex base metal ores, in fact I know of a case where autogenous grinding would be disastrous to any selective flotation. I do however contend that prospective flow sheets and reagent balances of any complex base metal ores should be tried with both types of grinding. I feel fortunate that the paper to be presented later in this meeting by Rene Klymouski will, I think, compliment and perhaps explain some of the results of my research.This paper will be in four parts. The first part deals with a literature survey on the subject. Surprisingly enough, very little information has been printed on the subject. The second part deals with results obtained in bench scale tests on an ore from Chester Mines Limited. It was in these tests that we realized that steel grinding was giving us serious problems. So bench scale tests are shown giving results with a stainless steel grind, a mild steel grind and a grind in a ceramic mill with ceramic billets.The third part of the paper deals with results obtained in the Mines Branch Pilot Plant, when again we ground the ore with three different types of grinding media. Incidentally, this has been the only pilot plant test made at the Mines Branch in which flotation products were made on both steel grinding and autogenous grinding on the same ore. The fourth part deals with two other New Brunswick ores and is intended to show that changing the grinding media effects ores other than that of Chester Mines Limited."

Jan 1, 1973

By L. Connolly, F. R. De Luca

"Rubber liners at Denison Mines Limited are used in 10 1/2x 24' low discharg0 pebble mills. These were originally 10 1/2 x 13 Dominion overflow type ball mills. Experience here shows that the wear of rubber and ni-hard lifters is approximately the same in the feed end half of the mill, while the wear of rubber lifters is much greater in the discharge half. The wear of rubber plates is considerably less than white iron in the feed end half of the Mill and slightly more in the discharge end half of the Mill. Rubber components are lighter to handle but their installation is time consuming. This leads to the conclusion that a combination of ni-hard lifters a~~ rubber plates is the most economical compromise in Denison's case, for the Mill. Rubber discharge grates are superior to steel grates, while steel feed end liners are superior to rubber.The Use of Rubber Mill Liners at Denison Mines LimitedGrinding is done in two identic0al circuits each consist-ing of one 10 1/2 x 14' Dominion overflow rod mill, two Dorr Oliver quadraplex rake type classifiers, two 10 1/2 x 24' Dominion low discharge grate pebble mills and ancillary pumps and conveyors for pebbles. There is one centrally located distributor box that receives the discharge of the 4 pebble mills and splits it out to the classifiers."

Jan 1, 1974

By N. M. Soonawala

Detailed regional geophysical and geochemical surveys, ground surveys and drilling were undertaken to follow-up the federal-provincial Uranium Reconnaissance Program (URP) over the 27,OOO-km2 Kasmere-Munroe area in northwestern Manitoba. An analysis of the URP data showed a fair correlation between the regional airborne radiometric results and lake-bottom geochemical results, both of which also correlated with the regional geology. More detailed surveys defined anomalies with greater precision within the broad zones outlined by the URP. The ground follow-up indicated that URP anomalies can be caused by varying degrees of uranium concentration in the rocks. Mineralization of interest was found in leucogranites at several locations within the survey area. Anomalous uranium concentrations were also found in coarse pegmatites and Hudsonian granitic intrusions. It can be concluded that large-scale regional surveys can be followed up in relatively short periods of time to yield meaningful results if a properly planned exploration sequence is employed, each stage of which successively narrows the area of interest.

Jan 1, 1979

By J. Davis, M. G. Reading

"INTRODUCTIONInternational Minerals and Chemical Corporation (Canada) Limited operates two potash mine/refinery complexes near Esterhazy, Saskatchewan. Annual production of approximately 4.2 million tons is sold in the United States and overseas in five grades according to size and quality.Ore grading 25% K2 0 equivalent is mined from a horizontal bed by continuous boring machines, crushed, and hoisted at 8 inches. The refinery operation consists of the eight basic steps shown in Figure 1. Particle sizes handled are similar to those experienced in other forms of mineral beneficiation: 8 inches to 100 mesh. The ore is crystalline and particles are angular. Fortunately the major mineral constituents, sylvite (KCl) and halite (NaCl), demonstrate relatively low hardness at 2 to 2.5.Therefore, while simple abrasion must be acknowledged, it is not a major problem except, of course, in circuits carrying magnetite.Corrosion, as represented by the classic equations of Figure 2, occurs in all its various forms."

Jan 1, 1983

By R. K. Netolitzky

The Weedy Lake, Tower Lake, and Wedge Lake gold deposits illustrate contrasting styles and different ages of mineralization within the same district. The discovery of these deposits was the result of systematic exploration of gold occurrences noted during research of assessment files. The Weedy Lake and Tower Lake depo its reflect a late-stage gold mineralizing event. The e deposits developed along the same major structural break, and also display simi lar mineralogy and alteration patterns. Mineralization is developed in all the lithologies present. The Wedge Lake property, while having occurrences similar to the Weedy and Tower deposits. has the more important Twin Zone which best fits a volcanogenic exhalative model. The Twin Zone has a complex structural history without a recognizable alteration halo. The setting may be proximal to a hydrothermal vent. Mineralization is hosted within a mixed ulphide/oxide/silicate facies iron formation breccia. and the gold is intimately associated with arsenopyrite. The origin and age of the brecciation is key to understanding the mineralizing event. Traditional prospecting procedures in conjunction with conventional B-horizon soil geochemistry were instrumental in the Twin Zone and Weedy lake disco,•eries. Tower Lake was a prospecting discovery partially defined by previous drill programs. This deposit was also identified by B-horizon oil sampling.

Jan 1, 1986

By Casey Erickson

Goldstrike Property ??Located in Elko, NV USA?Carlin Trend ??Mining Since 1985 ??27 Million Ounces of Gold Mined ??Production of 400,000 tons/day ??1,600 Employees

May 1, 2011