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By J. B. Boisvert, W. Board, C. R. Mooney

"Traditional geostatistical modelling methods are difficult to apply to heavy-tailed deposits because the extreme positive skew of the grade distribution leads to bias. The focus here is on an innovative method of modelling the high-grade population by conditionally simulating discrete volumes (nuggets) of gold with marked Poisson and Cox processes. Capping and other ad-hoc manipulation of the assay data is not required; however, an intensity map for the point processes is required. The method is demonstrated on a dataset from an epithermal deposit and demonstrates an improvement in reducing smearing and controlling the skew of the grade distribution.RÉSUMÉ Les méthodes traditionnelles de modélisation géostatistique sont difficiles à appliquer dans des gisements dont la distribution de la teneur est à queue lourde car l’extrême asymétrie positive de la distribution de la teneur génère des biais. Dans le présent article, l’accent est mis sur une méthode novatrice de modélisation de la population à haute teneur par la simulation conditionnelle des volumes discrets d’or (pépites) au moyen de procédés marqués de Poisson et de Cox. La limite d’utilisation et d’autres manipulations ad hoc des données ne sont pas requises; toutefois, il faut une carte des intensités pour le processus ponctuel. La méthode est démontrée sur un ensemble de données d’essais provenant d’un gisement épithermal et elle montre une amélioration dans le lissage du flou et dans le contrôle de l’asymétrie de la distribution de la teneur."

Jan 1, 2015

By M. J. Collins, B. Parekh, A. Hasenbank, B. Hewitt

Newcrest Mining Limited, originally as Lihir Gold, has operated a pressure oxidation plant for the recovery of gold from refractory ore since 1997. The mine and gold plant are located on Lihir Island in Papua New Guinea. Design of the original pressure oxidation circuit was based on the results of pilot plant tests conducted by Sherritt in Fort Saskatchewan. Following a decision to expand the plant in 2008, Lihir Gold contracted Sherritt to design a new autoclave. The design exercise utilized the original pilot plant test results, commercial process results at Lihir, and an understanding of advances in autoclave technology since the original plant was built. The new Lihir autoclave will be the largest horizontal, multiple-compartment autoclave in the world. The design process for the pressure oxidation expansion is described in this paper.

Jan 1, 2011

By R. W. Davis

INTRODUCTION CHURCHILL river was named for John Churchill, first Duke of Marl-borough and third Governor of the Hudson's Bay Company, in the latter part of the 17th century, some fifty years after the ill-fated Danish expedition, led by Munck, had abandoned the site of the now famous seaport of Churchill, as a worthless, cold, disease-ridden country. No other attempts were made to explore the interior until the river basin became a part of the grant to the Hudson's Bay Company and began to play its part in furnishing the luxury of fine furs to civilized people as it had furnished the necessities of food and dress for untold centuries to uncivilized natives. This was the sole contribution of the region to the economic life of the country for some two hundred and fifty years, until 1926, when the power site at Island Falls was discovered by engineers seeking a cheap power source to make possible the development of the great ore-body at Flin Flon. DRAINAGE BASIN OF CHURCHILL RIVER The river is some 1,325 miles long. Rising in the headwaters of the Beaver river, in east-central Alberta, it flows in an easterly direction across Saskatchewan and northeasterly across Manitoba to Hudson bay, through a remarkable basin of some 115,500 square miles, only 6,000 square miles less than the area of the British Isles. A journey down this river leads one through three distinct belts of country, each vastly different from the others geologically and in surface characteristics. For the first five hundred miles the river flows through a basin of 36,000 square miles of the great central-plains country, which is covered with fertile soil and carpeted in its southern part with prairie grass, which gradually gives way to the mixed forests of poplar, spruce, birch, and jackpine in the northern and eastern sections: About midway across Saskatchewan, bald-headed knolls and ridges begin to make their appearance as the river meets the western margin of the Canadian Shield. Then, for some seven hundred miles, it passes through country underlain by the pre-Cambrian rocks of the Shield, which continue to within one hundred miles of Hudson bay. Here the character of the country again changes to a low, clay plain underlain by sandstone, and through this 'clay belt' the river flows between steep clay banks, to empty into Hudson bay.

Jan 1, 1935

By Sylvie Lévesque, Frederic Couët, Laura Pérez-Barnuevo, Cory Hennessey

Determining mineralogical characteristics of samples throughout the iron ore concentration process – from drill core samples up to the concentrate – is critical to process improvement and remediation. However, assessment of mineral proportions, liberation, and texture, although essential, can be time-consuming and costly. Thus, a mineralogical study is often not performed or only restricted to a limited number of samples. New iron ore deposits or new ore zones in active mines will bring new challenges as they are known to be problematic due to their lower grades, complex textures and presence of mineral impurities. In those cases, applied process mineralogy will be necessary to understand and to diagnose potential processing issues. To take full advantage of mineralogical information along the iron ore concentration process, new tools are being developed to provide mineralogical data based on texture, composition and liberation. In an early stage at the mine, the automated identification of drill core textures could provide essential information for the prediction of ore concentrability and grindability. In a later stage, the automated modal tool, combining the knowledge of the iron ore mineralogy of a specific deposit and the results of chemical analyses, can quantify the mineral proportions of the ore; results show good agreement between mineral estimation via chemical analysis and modal analysis using a Mineral Liberation Analyser. A bulk mineralogical analyser allowing semi-quantitative evaluation of the liberation of iron oxides is being validated. The results from the bulk mineralogical analyser will eventually be linked with the mineral proportions issued by the automated modal tool to provide complete mineralogical characteristics of iron ore samples. Ultimately, these mineralogical tools could provide valuable and timely insight for predicting concentrators’ performances or troubleshooting gravity separation processes.

Jan 1, 2016

By J. D. Christian

WHEN mining development began in the Kirkland Lake camp, twenty-five years ago, there was very little information obtainable from surface showings as to the nature of the ore deposits. A length of almost a mile of the main 'break' lay under the south arm of the lake, and elsewhere most of the outcrops were covered with glacial drift. Shafts were sunk on ore-bodies of uncertain value, either on the outcrop of the veins or-because of the lake to the north-in the south or hanging-wall. In the second year of the camp's development, the Great War broke out and retarded progress for its duration. He would have been a real optimist who, in those early years, could have foreseen mining at depths of more than a mile.

Jan 1, 1939

By Art Hamilton

Abstract -The Zn-Pb-Cu-Ag ore deposits of the Boundary and N-5 zones near Bathurst, New Brunswick, occur in a polydeformed volcano-sedimentary sequence that is part of the Ordovician Tetagouche Group. Massive and disseminated sulfides are hosted by an argillaceous to cherty sedimentary sequence that is stratigraphically underlain by a siliceous fragmental unit and is overlain by a feldspar-rich crystal tuff and related tuffaceous rocks. The deposits have a low iron sulfide con­ tent relative to that of most stratabound sulfide deposits of the Bathurst-Newcastle mining district. The ore is commonly associated with chlorite- and talc-rich sediments. The N-5 deposit is considered to be the fault-displaced extension of the Boundary deposit. The Boundary deposit is estimated to contain 891 000 t grading 3.310Jo Pb, 7.96% Zn, 0.32% Cu and 44 g/t Ag; the estimate for the N-5 zone is 330 000 t grading 3.24% Pb, 7.15% Zn, 0.33% Cu, and 37 g/t Ag. The ore is processed at 1000 tpd at the Heath Steele mill.

Jan 1, 1992

By H. D. B. Wilson

"IntroductionRECENT ADVANCES in geo-chemistry and in •our knowledge •of crystal structure provide a key which enables us to create a systematic picture of the genesis of many ore deposits. This genetic scheme may be used with confidence in assessing certain types of orebodies and may be of some aid in actual exploration, since it affords a rational explanation of the dependence of the composition •of the ore minerals on that of the rock type in which they occur with which they -are •associated. For purposes of the present paper, .the elements chosen are •chromium, vanadium, iron, and titanium. The oxides of all these metals occur in deposits of similar or related type, and it is proposed to show that, for each, the composition of the •ore mineral is related to •the composition of the enclosing :rock, and that one of the principal factors controlling the composition of the ore is the ionic size of its constituent elements.Geochemical PrinciplesThe crystals of the rock-forming silicates and of the magmatic oxide minerals are essentially ionic types. This means that they are composed •of oppositely charged ions such as Mg²+ and 0²-, which are held together by electrostatic attraction. The ions of each element are spherical, with characteristic size known as the ionic radius. Crystals are built up by the packing of these spheres in the most stable arrangement compatible with the size and the size and valence of the ions• involved.Many of the principles governing the formation of ionic crystals are •simple ,and logical."

Jan 1, 1953

By C. P. Browning

Copper, as far as we know, was the first metal used by man, and due to the fact that it occurs in many places in the 'native' state, and also to the ease with which it may be shaped, it has played an important part in the evolution of civilization. Copper tools with inscriptions dating back to 6,000 B.C. are known in Egypt, where the metal probably got its start as a useful material in human hands. Just how far back the use of copper in Canada dates is difficult to say, but it was in use by the Indians in the Lake Superior country long before the arrival of the first white man. For many generations the Eskimos also have used copper derived fr0m deposits of the native metal found in the Coronation Gulf district. Due to the metal's many unique qualities, imperishable with age, ancient implements and utensils are apparently as good today as when they were made, having withstood the onslaught of time probably better than objects of any of the other base metals. Copper alloys so well with other metals that today it is second only to iron in its industrial value. Even at the beginning of the eighteenth century the world's production of copper was probably not more than seven thousand tons a year, with Great Britain producing three-fourths of this. One hundred years ago the mines of the United States, Chili, Mexico, Canada, South Africa, Australia, and Tasmania, which now produce about nine-tenths of the copper of the world, were totally undeveloped. Ln 1926 the world production of copper was approximately 1,658,000 tons, which was seventy thousand tons greater than in the preceding year; but growing demand absorbed the increased production, so that the stock of rough copper throughout the world is comparatively small. Of this huge tonnage of the metal, Canada produced four percent, two-thirds of it emanating from British Columbia, nearly one-third from the Province of Ontario, and the balance from Quebec.

Jan 1, 1927

By C. H. Hopper

THE gold orebodies of the Matachewan Consolidated mine are of particular interest geologically because of their odd shapes, their apparent lack of connection one with another, and the fact that they occur in a number of different formations. All of the orebodies exhibit a similar fracture pattern and the areas of fracturing appear related to the local folding. However, the lack of either horizontal or vertical continuity suggests additional controls not yet discovered. The question of origin, so ably discussed by H. C. Cooke in 1919, will be reviewed in the light of the additional evidence uncovered since his examination of surface trenches twenty-four years ago. The Matachewan Consolidated mine, with its neighbour, the Young-Davidson mine, is in Powell township, 25 miles by road northwest from Elk Lake, 30 miles west of Kirkland Lake, and 45 miles southeast of Porcupine. It may be considered as being on the westerly extension of the Kirk-land Lake sedimentary belt, where the rock column is markedly similar. There is no similarity in structure, however, for great ore-bearing shears and faults simply do not occur at Matachewan. Rather may it be said that the region, under stress, failed in isolated brecciated patches, some of which make up today's orebodies. The mine currently treats 1,000 tons a day of porphyry ore averaging 0.10 oz. gold per ton. It started operations in 1934 on greenstone ore, and the mill then treated 150 tons a day of ore averaging 0.23 oz. gold per ton. Total production to the end of 1941 has been 929,484 .tons averaging 0.160 oz. gold per ton.

Jan 1, 1942

By A. L. Mular

Some specific cases of the collection of data from industrial grinding and classifying operations, and the development of models from the data so obtained, will be described. The problems encountered, the effort involved, and the value of the derived models in improving the plant efficiencies will be discussed and documented where possible.

Jan 1, 1971

By Sherwin F. Kelly

With the progressive exhaustion of ore deposits easily discovered by surface prospecting, the attention of scientists is being turned more and more to the employment of mechanical means for the location of ore bodies whose outcrops are not visible. The dip needle, the Eotvos Torsion balance, and various methods of electrical prospecting are illustrative of the modem tendency. Interest in the possibility of applying electricity to the solution of many of the prospector's problems dates much farther back than is usually realized. The first person to notice an abnormal intensity of electrical activity in the region of certain ore bodies was an Englishman, R. W. Fox, who experimented on the Cornwall copper and tin veins about 1830. Dr. Barus, in the United States, carried the early experiments a step further in his work on the deposits of Eureka, Nevada, about 1880. He made the very definite suggestion that the phenomena noticed would be of material aid to the prospector. Not until Professor Schlumberger, of the Ecole des Mines, Paris, took up the matter, shortly before the war, was any definite effort made to put electrical prospecting on a commercial basis. His work resulted in the establishment of sound principles and practicable field technique, for two distinct methods of prospecting.

Jan 1, 1924

By R. W. Boyle

"EDITOR'S NOTEPart 1 of this paper, published in the August issue, covered lithochemical surveys based on major, minor and trace elements in whole-rock samples from primary enveloping halos.Part 2, which follows, continues with discussions of surveys based on leakage halos, zonation of elements, stable and radioactive isotopic distributions, and geothermometric, geobarometric, thermoluminiscent, pedochemical, hydro-chemical, atmochemical and biogeochemical methods. It concludes with a selected bibliography.Surveys Utilizing Leakage HalosLeakage halos can be used as scalar or vector quantities in thesearch for deeply buried blind mineral deposits. In the first case, the occurrence of a leakage halo (e.g. a small pitchblende seam) may simply indicate the possible presence of pitchblende mineralization or orebodies; in the second case, the areal or three-dimensional distribution of leakage halos may, by their increasing frequency and I or increasing metallic or gangue element content, provide a means of vectoring in on loci of mineralization and orebodies. Examples of both cases are given in the following text.Leakage halos are of many types, as shown in Figure 2 (Part 1), and are best discussed with respect to their associated mineral deposits. Furthermore, it should be noted that leakage halos are frequently offshoots or extensions of enveloping halos. Where this occurs, careful tracing of the leakage halo(s) downward or upward respectively will often lead to the apex or nadir (bottom) of the enveloping halo(s) and ultimately to mineralization or ore."

Jan 1, 1982

By Ree Llewellyn

"It has been estimated conservatively that the costs of wear damage and friction in the Canadian mining and mineral processing industry amount to over one billion dollars per year. These are mainly incurred through the repair or replacement of worn parts and production losses from related equipment downtime. The selection and application of the most appropriate wear protection components and systems, can thus have a very significant influence on productivity, profitability and global competitiveness.Details are presented of the wide diversity of materials used to counteract the varied and often complex wear attack mechanisms that occur in surface mining. The majority are various forms of steels and irons with generally very high hardness. However, they also include relatively soft elastomers and polymeric products.The main characteristics and applications of the different classes are reviewed. Case studies record significant performance improvements achieved through more judicious selections. Finally, some new developments which reduce maintenance charges by substantially increasing wear component life, are described."

Jan 1, 1996

By G. W. Smith

"The adsorption of dehydroabietylamine acetate on quartz, hematite, rutile and baddeleyite has been deter-mined for concentrations ranging from 0.3 to 5,600 µ. moles/I and for pH values ranging from 2.5 to 10.5.The surface tension, UV and IR spectra, equivalent conductance and ion concentrations for dehydroabiety lamine acetate solutions have been determined.Contact-angle and flotability studies have established that good collection may be obtained with this amine but that selectivity depends on the suitable use of depressants for some of the minerals."

Jan 1, 1971

By C. Samuelsson, H. Ahmed, B Björkman, A. Andersson

The cost of raw material and energy is a continuing driving force towards working with increasing the recycling of ore based steelmaking residues. In Sweden no on-site sinter plants are operated at the integrated steelworks. Instead, selected residues from the plant are incorporated in a cold bonded briquette product which is recycled to the process via the blast furnace (BF). Since the BF sludge is the major bleed of zinc out of the furnace it is required to be de-zinced prior to recycling in the briquette product. In the present work landfilled BF sludge has been characterized with respect to chemical composition, particle size distribution, X-ray diffraction (XRD), and scanning electron microscopy (SEM). The sludge was also subjected to laboratory scale hydrocyclone trials aiming at reducing the zinc content making the sludge viable for recycling. The results suggested that the sludge had been agglomerated prior to the characterization and hydrocyclone treatment. The zinc removal using the hydrocyclone was discussed.

Jan 1, 2015

By Arthur. H. Winckers, Stephan L. Chryssoulis

"The deportment of gold in residue samples of cyanide leach tests of David Bell ore from level 6A block 13 was established using a comprehensive quantitative mineralogical approach. In every test the feed was first pre-aerated for 4 hours, followed by 48h cyanidation. Test no. 2 was done without lead nitrate and yielded a residue assaying 3.03g Au/t. In test nos. 4 and 9 lead nitrate was added before pre-aeration at 0.03kg/t and 0.3kg/t respectively yielding residues of 1.04 and 0.81 g Au/t.The mineralogical approach employed to establish the deportment of gold involved superpanning, to preconcentrate the free gold and assaying of the tailing fraction to determine the gold associated with quartz. It was thus determined that without lead nitrate added 47.2% of the lost gold is in the form of residual free gold particles less than 20 µm in size. It is this form of gold which is under represented in the residues of leach tests with lead nitrate added.Having eliminated coarseness of gold particles as a factor for lower recovery, it was determined that the residual gold particles have extensively contaminated surfaces. Amongst the deleterious surface contaminants identified: S, As, Ag, Sb and Hg, the two most harmful are S and Hg because of their concentration on the surface and rate of accumulation.Mercury and Ag are minor constituents of native gold at David Bell (average composition Au: 78.9 wt%, Hg: 18.5 wt% and Ag: 2.6 wt%) and they become enriched on the surface of residual gold particles because of their slower rate of dissolution in cyanide. The other elements absorb onto the gold particles from solution.The beneficial effect of lead nitrate was documented by comparative surface analysis of gold from residue samples of 48 hour leach testing with and without lead nitrate added and from time dependent (0-2 hour) leach tests in the presence and absence of lead nitrate. Lead nitrate accelerates the dissolution of gold by performing the following functions: (i) catalytic effect on the cyanidation of gold by accepting electrons; (ii) reaction with surface sulphur to form PbS which is then removed by oxidation; (iii) catalytic reaction on amalgam and Ag facilitating the cyanidation of Hg and Ag thus slowing down their build up onto the dissolving gold particles and (iv) the precipitation of sulphide sulphur from solution thus minimizing its build up on the surface of dissolving gold particles which is believed to facilitate the access of cyanide ions."

Jan 1, 1996

By S. Bastola, Y. P. Chugh

"This research determines shear strength and stiffness properties of bedding planes and joints in the roof strata rocks within 7.5 to 9 m (25-30 ft.) overlying the Illinois #6 coal seam (within the pressure arch zone). A shear test loading device was designed into a 1.334 kN (150 t) Forney Compression Loading Machine to perform direct shear tests in accordance with ASTM D5607-08 “Standard Test Method for Performing Laboratory Direct Shear Strength Tests of Rock Specimens under Constant Normal Force”. The data were used to determine peak and residual friction angles and the dilation angle. A total of 49 bedding plane samples were tested, out of which 46 (36 intact and 10 relatively weak and loose) samples passed QA/QC procedures in accordance to ASTM D5607. Samples from eight (8) different bedding planes- shale/limestone (SL), shale/sandstone (SSs), shale/bone (SB), laminated sandstone (LS), shale/shale (SS), bone/bone (BB), bone/limestone (BL), and limestone/limestone (LL) were tested. The number of samples tested for each bedding plane were: SL- 11, SSs- 8, SB- 5, BB- 4, LS- 6, SS- 9, BL- 1, and LL- 2. Peak and residual shear strength values at 2.75 MPa normal stress range 1.06 – 6.26 MPa and 0.82 MPa to 0.82 – 4.14 MPa, respectively. The average normal and shear stiffness values are about 11.98 GPa/m and 3.11 GPa/m. Dilation angles are low (<10?) and negative in some cases. Angle of sliding friction values range from 9? to 42?. Joint Roughness Coefficient (JRC) values were less than 10.INTRODUCTIONRock mass may be defined as the total in situ rock medium containing bedding planes, faults, joints, folds and other structural features. Therefore, it is discontinuous and may have heterogeneous and anisotropic engineering properties. Upon creation of an excavation in a rock mass, bedding planes and joints are the most likely points of failure initiation. The failure typically occurs either in tensile or shear mode. Upon failure initiation stresses are transferred to the neighboring rock mass and the failure progresses until stability is achieved through equilibrium of stresses and strength. An example of this mechanism is development of the pressure arch. This study determined the shear strength and stiffness properties in shear and compression of bedding planes and joints in the immediate roof strata rocks within 7.5-9 m ( 25-30 ft.) overlying the Illinois No. 6 coal seam (within the pressure arch zone). Since such data are currently not available for Illinois Coal Basin mines, researchers and engineers have been using estimated values for design purposes. The immediate roof lithology in the proposed mining area consists of shale 0.62 m; Bone 0.09 m (0.3 ft.); Limestone, 0.10 m (0.33 ft.); Shale 2.37 m (7.9 ft.); and sandstone 0.55 m (1.83 ft.). The bedding plane samples were provided by a mine in south-eastern Illinois operating at a depth of about 180 m (600 ft.)."

Jan 1, 2015

By J. D. Wright

This paper describes current milling practice at Endako Mines Ltd., a molybdenum producer in central British Columbia. The various steps in the crushing, grinding and flotation of the ore are outlined, with emphasis on the metallurgy of the latter operation. Tailings disposal and concentrate assaying methods are also described.

Jan 1, 1969

By P. Clinton Milne

Uranium mines in Washington State include the producing Midnite and Sherwood mines and several mined-out deposits, the most productive of which was the Daybreak mine. The Midnite mine is generally classified as a hydrothermal deposit consisting of tabular orebodies in Precambrian pelitic and calcareous metasedimentary host rocks. The host rocks occur as roof pendants in a Cretaceous porphyritic quartz monzonite intrusive; the quartz monzonite averages 12 ppm U308 The uranium deposit appears to have undergone a complex genesis, involving a series of depositional and enrichment stages. The Sherwood uranium deposit, approximately 4 miles south of the Midnite mine, occurs near the bottom of a basal Late Cretaceous to Paleocene arkosic conglomerate. The conglomerate lies nonconformably on the porphyritic quartz monzonite that is associated with the Midnite deposit. The Sherwood and Midnite uranium deposits may have had a similar genetic history linked by a common uraniferous pluton source, ground-water action, and/or leaching of uranium-rich ash flows from now-eroded, overlying, Eocene volcanics. The Daybreak deposit, in northeastern Spokane County, consists entirely of secondary uranium mineralization (metaautunite) in a quartz monzonite pluton. Mineralization is confined to a low-angle fault zone and is most highly concentrated at the intersection of primary and secondary shears. Both hydrothermal and ground-water origins are feasible. Besides the Midnite-Sherwood area, 14 other areas in the western Okanogan Highlands physiographic province and Cascades region have favourable characteristics for uranium potential. Criteria include the existence of uranium occurrences, Tertiary basin sediments with intercalated volcanic and volcaniclastic rocks, favourable geochemical data, alkaline plutons associated with uranium occurrences or borders of Tertiary basins, and structural controls.

Jan 1, 1979

Who is CIBC? ? Canadian Imperial Bank of Commerce (?CIBC?) is a leading North American financial institution. ? Total Assets: US$315 billion ? Market Capitalization: US$29 billion ? CIBC comprises three strategic business lines: ? CIBC Retail Bank ? CIBC Wealth Management ? CIBC Wholesale Bank ? CIBC Wholesale Bank is a leading North American investment bank with niche capabilities in Asia, Australia & Europe. ? 1,000 + employees around the world ? Product range includes: Mergers & Acquisitions advisory and financing, Equity and Debt issues, Merchant Banking and Strategic Lending ? CIBC is ranked as the #1 investment bank in Canada across most of its key products and industries ? #1 Equity Underwriter in Canada ? #1 Mergers & Acquisitions Advisor in Canada

May 1, 2010