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By R. B. Allen, E. E. N. Smith, B. C. MacDonald

"LocationTHE MAIN PROPERTY and townsite of Eldorado Mining & Refining, Limited, Beaverlodge Operation, is on the north shore. of Beaverlodge lake, •about seven miles north of the deserted town of Goldfields on lake Athabasca, and four hundred and ninety air-miles equidistant from Prince Albert, Saskatchewan, and Edmonton, Alberta. Both Eldorado Airlines •and Canadian Pacific Airlines maintain scheduled flights from Edmonton to the 4,000-foot airstrip on the north boundary of the Company property. Bi-weekly flights are made by Saskatchewan Government Airways from Prince Albert. Men and priority freight are flown by Company aircraft direct from Edmonton. From June to-September, when the waterways .are ice-free, freight is carried by barge from the •railhead at McMurray, Alberta, down the Athabasca river to Chipewyan, and across lake Athabasca to• Bushell, the terminal on Black bay, lake Athabasca, a total distance of 265 miles.The Eldorado Operation has been connected by a 12-mile, all-weather highway to Bushell. Where the highway crosses the park-land along the Fredette river, the townsite, Uranium, is under construction to provide services to the uranium-producing district. Spur roads have been built to the Ace, Fay, Eagle, •and Martin mines of the Eldorado operation, and to the properties of Pitch-Ore Uranium Mines, Ltd., and Rix Athabasca Uranium Mines, Ltd."

Jan 1, 1954

By Nancy E. Wilk

In 2015, more than 1.2 million deaths annually were estimated to be caused by occupational risks (WHO, 2018). In 2021, this estimate increased with the publishing of the World Health Organization (WHO) and the International Labour Office (ILO) Joint Estimates of the Work-related Burden of Disease and Injury based on data from 2000 to 2016 (WHO/ILO, 2021). These global estimates reported that each year 1.9 million people die from exposure to occupational risk factors, 81% of these fatalities resulting from non-communicable, occupational diseases. WHO/ILO notes that the health-related risk factors with the largest number of attributable deaths were exposures to long working hours followed by workplace exposures to particulate matter, gases, and fumes. The health outcome with the greatest work-related burden of deaths was chronic obstructive pulmonary disease, followed by stroke and ischaemic heart disease. In considering the 2021 data published by WHO/ILO, it is likely that the estimates are low and underestimate the true burden of occupational disease and injury. In support of that position, more recently the ILO estimated that “2.3 million women and men around the world succumb to work-related accidents or diseases every year; this corresponds to over 6000 deaths every single day” (ILO, 2022).

Jan 1, 2023

By O. Hall

DISCUSSION AT QUEBEC MEETING MR. A. V. CORLETT: With drill holes radiating from a common point, is loading carried to the collars, and do you undertake to distribute the powder evenly? MR. R. V. PORRITT: When the collars of the holes, particularly the diamond-drill holes, are close together, two out of three holes are loaded only to within six or seven feet of the collars, and the intervening holes are loaded close to the collars. When the collars are farther apart, the holes are loaded close to the collars. No spacers are used, and the holes are filled solid with powder, this applying particularly to the diamond-drill holes, except, of course, where the collars are close together and some holes are not loaded close to the collars. MR. J. G. L. McCREA: I would like to enquire in respect to the various efforts made to reduce the cost of diamond drilling to the lowest point, what is. the relative cost of the solid bit to the standard bit? It would seem that the solid bit has the higher cost. MR. PORRITT: The non-coring or solid bit gives a slightly lower diamond cost than the coring bit. With the coring bit, the greatest diamond loss is on the inside stones, apparently due partly to vibration, but mainly to the core blocking against these stones. This condition, of course, does not apply with the non-coring bit. Our experience is that the non-coring bit, which drills out a much greater area, has a diamond consumption slightly less than the coring bit. The non-coring bit is sturdier, and is far less liable to damage in starting holes and in drilling through cracked or broken ground.

Jan 1, 1939

By S. Koski, J. Vanderbeek, J. Enriquez

"The Cerro Verde copper-molybdenum porphyry mine, majority owned and operated by Freeport- McMoRan Copper & Gold, is located 30 km southwest of Arequipa Peru. The concentrator, which produces copper and molybdenum concentrates, started operating in late 2006 with a 108,000 tpd design capacity, processing primary sulfide ore (mainly chalcopyrite and molybdenite). Plant capacity was recently increased to 120,000 tpd. The comminution circuit consists of one 60” x 113"" primary crusher, four MP-1000 secondary crushers in closed circuit with dry screens, four 2.4m x 1.6m High Pressure Grinding Rolls (HPGRs) in closed circuit with wet screens, and four 7.3m x 11m gearless ball mills in closed circuit with cyclones. The HPGR circuit is fed by the Secondary Crushing circuit product at a T80 of 35 millimeters, and the HPGR circuit product feeds the Ball Mill circuit at a T80 of 3000 microns.This paper describes operating experiences with HPGRs during these first four years highlighting improvements in operating practices and presentation of data regarding operational efficiencies, also discussed are the primary benefits provided by HPGRs such as production of micro fractured particles, reduced ore Bond Work Index, and reduced power consumption. Cerro Verde represents the first installation of HPGRs in both the copper industry and large scale hard rock mining."

Jan 1, 2012

By K. N. Karparov

?Two highwall failures in a South African coal mine defied analysis by widely accepted limit equilibrium methods. ?The geological conditions were complex, with undulating coal-bearing strata overlying a karstic topography formed in underlying dolomite belonging to the Transvaal Supergroup. ?It was clear that the simplifying assumptions made by all limit equilibrium methods were inappropriate in the conditions.

May 1, 2007

By C. Paulo, W. N. Wheeler, M. Kalin, M. P. Sudbury

Many researchers have tested the addition of various phosphatic materials, including Natural Phosphate Rock (NPR), to mining wastes. It was assumed that iron in the waste would form FePO4 precipitates, restricting oxygen access to pyrite surfaces and reducing oxidation. Phosphate additions were based on stoichiometry (phosphate mass to sulphide content of waste). Although some interesting, positive results were obtained with low dosages, these were considered accidental, not having followed the expected stoichiometry. In 1991, we began experimenting on tailings and waste rock with NPR, postulating that if chemo-lithotrophic microbes on the mineral surface accelerate oxidation, then heterotrophic (oxygen-consuming) microbes would reduce oxidation. All wastes with NPR produced effluents with elevated pH and low metal acidity. Later, microscopic investigations of the rocks found an organic layer on the mineral surface, which was confirmed by independent research organizations repeating experiments with very low NPR mass additions to sulphidic wastes. In 2013, heterotrophs were identified and quantified as they grew on German lignite with NPR. These data conclusively showed that the development of heterotrophic biofilms is a consequence of adding waste NPR leading to a reduction of sulphide oxidation and improved effluent from sulphidic mining wastes. We document our gradual understanding of the effects of NPR on the reduction of sulphide oxidation, covering 23 years of research.

Jan 1, 2014

By M. Leroux, S. R. Rao, J. A. Finch

"Poor Pb/Zn selectivity during Pb flotation in laboratory tests on a Mississippi Valley-type Pb/Zn ore was traced to a pH effect. In the pH range 9.5-11 sphalerite floated readily without copper activation. Compared to sphalerite flotation with copper activation this procedure gave equivalent selectivity but reduced flotation rate.Possible mechanisms of this sphalerite flotation without copper activation are discussed. Activation by Fe(OH) 2 is suggested, the Fe++ions being derived from superficial oxidation of pyrite in the ore.INTRODUCTIONGalena and sphalerite commonly occur together. The usual practice is to float galena first followed by the flotation of sphalerite after activation with copper (II) sulphate. If ores contain pyrite it is depressed by maintaining an alkaline pH (9- 10) and using NaCN as depressant.In flotation tests with a Pb/Zn ore from Polaris selective flotation of galena could not be achieved consistently as a considerable amount of sphalerite, even though unactivated, floated. A systematic study was carried out to determine the cause of this problem. This led to the unexpected finding that sphalerite floated in the alkaline pH range 9.5-11.0 without preactivation with Cuso 4 . This paper describes the results of this study and discusses a possible mechanism of the flotation of sphalerite."

Jan 1, 1987

By Chuck Crowell

ISO Standards ?Provide Information to Address Commercial and Safety Needs for Standardization: ?Definitions and Terminology ?Test Methods ?Performance Criteria ?Conformity Assessment Process ?Developed by Global Experts ?Promote Global Harmonization

May 1, 2013

By A. T. GRIFFIS, R. J. GRIFFIS

A large magnesite-talc body is locared in Delora Township, 11 km sourh-southeasr of Timmins, Onrario. The deposit occurs in part of an Archean greensrone belt dominated by volcanic and sedimenrary rocks and large bodies of ultramafic intrusions. The magnesite-talc zane is abour 1800 m long, has a maximum width of 300 m and has been drilled ro 120 m below surface. Chemical analyses of rhe main carbonate zane average 20 ro 28% soluble MgO (magnesia), 5 ro 6% rota/ iron oxide and less rhan 0.1 % CaO (lime). Mineralogically, the zane consists of approximately 54% magnesite, 28% rate, /5% quartz and 3% hematire. Perrographic srudies suggest that rhe various assemblages of magnesite, rate, quartz and serpentine were derived from a parenr serpenrinire (after dunire). An early carbonitization stage, which produced a high-magnesite, low-talc assemblage, preceded a farer decarbonitizarion stage, which formed rhe main magnesite-talc assemblage. Despite a favourably low calcium oxide content of rhe magnesite-talc rock, considerable iron in the magnesire /at rice has limited the quality of the beneficiared product: rhe besr flotation concentrate to dare yields 92 to 94% dead-burned MgO. Experimen- I L t r i i c:~:.•-4- -------- ? -_;> ,•----1---- ta/ work continues on finding a process whereby high-purity magnesia can be produced on a commercial scale.

Jan 1, 1984

By Charles W. Villiers

AS is well known, there are large and valuable deposits of coal in British Columbia, both on the mainland and on Vancouver island. These deposits are widely distributed over the Province. The chief sources of supply on the mainland are found in the Fernie and Princeton-Nicola districts and on Vancouver island in the Comox and Nanaimo districts. The coals range from a very high quality bituminous coal to lignite. On the Upper Skeena river there is said to be a very large deposit of anthracite or semi-anthracite, but this field has not been developed. Coal was first discovered in British Columbia on the north end of Vancouver island in the year 1835, but it was not until 1852 that coal mining was seriously undertaken by the Hudson's Bay Company at Nanaimo, where mining has been carried on continuously ever since that date. The production of coal in the Province continued to increase until the year 1910, when the annual output reached its peak at 3,100,000 tons and a total of 7,800 men were employed in the industry. Since 1910, the production has dropped steadily until, in 1934, only 1,347,000 tons of coal were produced and less than 3,000 men were employed. This continued decrease in production has in no way been caused by lack of coal reserves. It has been due entirely to curtailment of markets. I do not propose to discuss coal mining practice in British Columbia, where we have all sorts of mining conditions, including submarine mining. There is no lack of coal supplies for either industrial or domestic purposes, nor is there likely to be any shortage of coal in the Province for many generations. We have our mining troubles, which increase the cost of production, but there are no insuperable difficulties to prevent the extraction of a large and increasing supply of coal. Our main difficulty-in fact our only serious difficulty-is to find a market for our output, and we must consider means which can be evolved not only to conserve our existing markets but also to expand them, at any rate within the boundaries of Canada. I will therefore confine my remarks chiefly to the all-important factor of Markets for our coal.

Jan 1, 1936

By W. T. Boyes, J. M. Harrison

"Squall Lake Gold Mines, Limited, owns a group of claims at Squall lake, northern Manitoba, about 75 miles east of Flin Flon and 3 to 4 miles north of the Nor-Acme mine at Snow lake. Gold mineralization was discovered in this locality several years prior to 1944, but it was only in that year that a comprehensive examination of the occurrences was begun. Development work to the end of 1946 has been encouraging and the deposits show interesting relations to rock structure.GEOLOGICAL SETTINGThe gold occurs in a sill of biotite-hornblende diorite at or near its contact with gneisses derived from arkosic sediments . In detail, the contact between the diorite and the arkose to the southeast of it is irregular, with interfingering of the two rock types. On the northwest side of the sill, between it and Squall lake, the rock is staurolite schist (see accompanying sketch-map).Several mineralized shear zones are known, of which those shown are the most important. Within the zones, the diorite is silicified and somewhat carbonatized. Fairly coarse arsenopyrite is the chief sulphide mineral in these zones but, locally, they contain also pyrite and pyrrhotite. Where quartz and chlorite are present, rather coarse gold is associated with them. In that part of the main zone where gold assays have been most consistent, the diorite is rich in albite."

Jan 1, 1954

By D. A. Brown, C. Lowe

"Abstract -A multi-sensor (electromagnetics, magnetics, gamma-ray spectrometry, and VLF) geophysical survey was recently conducted in the Purcell Basin of southeastern British Columbia in an area encompassing the world-class Sullivan Sedex deposit. The purpose of the survey was to geophysically characterize the known mineral occurrences and to develop strategies to enhance future mineral exploration in the basin. Follow-up investigations of geology and measurements of rock physical properties helped constrain interpretations of the geophysical data sets.Despite extraction of more than 90% of the ore from the Sullivan deposit, it is clear that the mineralization there, as well as at other Sedex occurrences surveyed, is characterized by high conductivity values, strong bedrock conductors, and elevated magnetic anomaly values. The albite-sericite alteration which accompanies this mineralization yields high potassium and low thorium-potassium ratio values. Associated Moyie gabbro is characterized by low electrical conductivity and radioelement concentrations and by high magnetic anomaly values. The study has also aided exploration for other mineral deposit types including stratabound Cu-Ag, placer gold, vein and disseminated basemetal deposits. In addition, the geophysical data have helped constrain geological interpretations of the basin."

Jan 1, 1998

By W. L. Uglow

In recent years, the microscope has come to be recognized as a valuable aid to engineers whose business is the discovery, development, concentration or reduction of metallic ores. In many of the large treatment plants microscopical research has already an important status; and in the hands of efficient operators the microscope has indicated methods of solving ore problems resulting in the saving of thousands of dollars that otherwise might have been lost in tailings, or expended in freight rates or smelter charges. Failure to procure all the information that the microscope can supply concerning the physical and mineralogical characteristics of complex ores has in many cases led to the construction of unsuitable concentrators, just as the failure to investigate in detail the geological conditions of an ore deposit has often results in the squandering of money on shaft sinking, and mechanical installations which subsequent development of the deposit failed to justify. The great progress recently made in the selective separation of minerals by means of the various processes of flotation and leaching brings strongly to our attention, the scope of the field in which microscopical methods may be advantageously employed. The microscope enables one to observe the minute details of rock, ore, gangue, concentrate, tailing, matte, slag and metal, that are invisible to the naked eye. Furthermore, the technique of microscopal research has been so highly developed that a microscopist can not only observe, but deter-mine the compositions and measure the diameters of the mineral constituents in the ore to be treated. Magnifications of these constituents up to 3,000 diameters may be produced by the proper combination of eyepiece, objective, and projection apparatus, and the images thus viewed may be photographed through the microscope, and permanent records made of them.

Jan 1, 1924

By M. Proulx

"RÉSUMÉ Le diagramme ternaire Al2O3-Sr-Y est un nouvel outil servant à l’exploration de gisements de sulfures massifs volcanogènes (SMV) archéens. Le diagramme permet de discriminer entre les roches volcaniques à minéralisations à zinc dominant (domaine Zn+) et celles à minéralisations à cuivre dominant (domaine Cu+), ainsi que les roches volcaniques ayant subi une chloritisation hydrothermale pouvant aboutir à la formation de chloritites associées aux cheminées d’altération (domaine Cl+). Ces trois domaines délimitent des zones d’influence géochimique ou d’empreintes hydrothermales résiduelles ou fossiles produites par les cellules de convection hydrothermales générées par des magmas. Le diagramme permet aux sociétés d’exploration de déterminer de façon peu coûteuse la fertilité potentielle des roches volcaniques archéennes en ayant recours à leurs bases de données et aux résultats de leurs analyses de terrain, sans aucune manipulation des données. Le diagramme ne s’applique pas aux SMV aurifères.ABSTRACT The tertiary diagram Al2O3-Sr-Y is a new tool to explore Archean volcanogenic massive sulphide (VMS) deposits. The diagram can be used to discriminate between the volcanic rocks where zinc is the dominant mineralization (Zn+ domain) and the rocks where copper is the dominant mineralization (Cu+ domain), as well as the volcanic rocks that were subjected to hydrothermal chloritization that could have led to the formation of chloritites associated with alteration chimneys (Cl+ domain). These three domains define the zones of geochemical influence, or residual or fossil hydrothermal footprints produced by hydrothermal convection cells generated by magmas. Exploration companies can apply the diagram to determine, at low cost, the potential fertility of the Archean volcanic rocks by using their databases and the results of their field analyses, without any data manipulation. The diagram does not apply to gold-bearing VMS deposits."

Jan 1, 2015

By J. H. McKibbon

This paper outlines the basic steps in the sizing of electrostatic precipitators according to the Deutsch equation. Design parameters that do not appear in the equation are also described.

Jan 1, 1971

By M. Tanaka, H. Narita, T. Fuchikami, K. Morisaku, K. Nagao, T. Yoshida, K. Kuroda

The effect of various N-substituents on the performance of amide-containing tertiary amine compounds in the extraction of Rh(III) from HCl solutions was investigated to optimize the structure of these compounds for industrial use. It was found that N-2-ethylhexyl-bis(N-di-2-ethylhexyl-ethylamide)amine and tris(N-di-2-ethylhexyl-ethylamide)amine, which have long, branched alkyl chains, were suitable for Rh extraction, because they were soluble in a practical diluent (80 vol% n-dodecane?20 vol% 2-ethylhexanol) and stable against highly concentrated HCl/Rh solutions, and showed high selectivity for Rh(III) over Pd(II) and Pt(IV).

Jan 1, 2014

By William M. Luff

"The Bathurst area has recorded mining production as early as 1837, although the bulk of the production has come in recent years. Production has been mainly from the well-known massive sulphide deposits, but vein, gossan, and a variety of other deposits have also been mined. This paper summarizes the history of the mined deposits, along with tonnages and grades produced. A number of ""firsts"" have been noted in the Bathurst area. The A Zone deposit, located in the Heath Steele area, was the first in the world discovered using airborne electromagnetic methods. Heap leaching of gold from the gossan zone at Caribou was the first operation of its kind in Canada. The Keymet mine was the first base metal (lead-zinc) mine in New Brunswick. For the past few years, the Brunswick No. 12 mine has been one of the largest zinc mines in the world.IntroductionThe Bathurst area (Fig. 1) first had mining production in 1837 when copper was mined from a deposit on the Nepisiquit river (MacKenzie, 1958). The majority of the production, however, has been in recent years from massive sulphide deposits, but there are also other significant operations. . Table 1 is a summary of Bathurst area mineral production, showing concentrator feed tonnages and mill feed grades. The table does not include peat deposits, sand and gravel, dimension stone or rock quarries. Figure I is a general geology map of the Bathurst area, indicating deposit locations. The deposits are divided into four categories: massive sulphide, vein, gossan and other. The deposits in each category are described in chronological order of exploitation."

Jan 1, 1995

By Frank Lemy

This paper presents an application of digital face mapping in an underground mine. Based on photographs it was possible to construct discontinuity maps, which were used to characterise the rock mass. The results were compared favourably with values obtained through scanline and area sampling mapping for the same site. The case is made for digital mapping as a safe, fast, and efficient way to characterise rock mass structure for engineering purposes.

May 1, 2001

"HPGRs operate in a wide array of applications in mining and minerals. These range from relatively coarse crushing of copper and gold ores at one end of the spectrum to the processing of fine iron ore pellet feed and fine industrial mineral products at the other. Traditionally these circuits involve the treatment of relatively moist materials in pre-grinding circuits; using single stage HPGRs in open circuit or as a closed circuit operation with screening or partial product recycle. More recently, HPGR is increasingly deployed in dry grinding in combination with air classification. The high throughput demonstrated by larger HPGRs has stretched the application towards coarser size reduction duties for a number of new projects. At the same time, the basic principle of inter-particle crushing for generating a product with a high fines proportion gives ground to investigate applying the technology further towards finished product duties. The advantages that HPGR brings are clear. Multi Stage grinding enables energy efficient size reduction across more of the comminution circuit. Primary HPGR serves for a coarse grinding duty, whereas a secondary HPGR is geared towards generating a fine product for downstream processing or even a finished product. This publication summarizes some of the features of staged HPGR circuits and discusses some examples of operating and projected applications.INTRODUCTION In most HPGR applications, the grinding units are used as a single process stage, either in open circuit, such as for pebble crushing [Rose 2002, Westermeyer 2000, Van der Meer 2015] or in closed circuit with classification [Van der Meer 2009, 2012] or product recycling [Van der Meer 2010]. Where a higher plant capacity is required, the HPGRs are commonly installed in multiple lines in a parallel arrangement [Parker 2005, Koski 201, Vanderbeek 2006]. HPGRs can take a wide range of feed size distributions, and grind this down to a product with a high fines content. In general view, there is a limit on the size reduction range that even an HPGR can provide. Grinding down from a very coarse ore (e.g. 70-100 mm) to a very fine product (e.g. 100 microns range) is stretching the ability of a single stage HPGR circuit. Fine grinding generally requires a classification stage that returns the classifier oversize to the head of the HPGR circuit. From one point of view, it can be demonstrated that when recycling a large proportion of fines and middlings back to the HPGR feed results in an effective feed with an overrepresentation of middlings and fines, which will eventually reduce the grinding efficiency and consequently result in an increased recirculation mass flow [Van der Meer 2014]. From another point of view the large recycling mass puts a strain or even a limit on the capacity of present-day conveyor capacity."

Jan 1, 2018

By Vilkul Yuri

Operation of the iron ore deposits of Krivbass which has been going for 130 years, has led to serious problems related to reaching great depths in open pit and underground mining. Extraction of the huge volume of rock mass (about 9 billion m3) resulted in mass violations of the natural state of the subsurface. At present most mining operations are carried out either by combined open pit and underground mining or by open pits in areas underworked by underground mining. Now the process of movement of the strata underworked by underground mines is not completed ? work fronts of open pits approach the areas of possible funnel, terrace and fissure formation, movement continue to develop. With deepening mining operations the remaining reserves are worked off under layers of incumbent rocks of > 900 m. Significant underground voids arise from mining "blind" deposits at large depths. Heaving of voids over the mined area lasts for decades; it may result in not only unpredictable time of funnel emerging and area development of movement synclines, but also the threat of air blows in mines. Forced caving of incumbent rocks as a way of controllable backfilling is difficult to achieve for economic and technical reasons. This is much more expensive and dangerous than stoping. Furthermore, the mining practice does not know examples of enormous volume backfilling under a km thick rock layer. Currently, RMI "KNU" is conducting research and pre-design work directed at creating a specialized pilot Geoinformation System (GIS) of continuous remote monitoring of rock mass in areas of underground voids influence in Krivbass area. Implementation of this system will enable to determine promptly in time and space the areas of the beyond cut off stress condition, to inform about possible occurrence of events that may result in accidents and to improve safety of mining along with other systems of forecasting and controlling the stress condition in rock mass. RMI "KNU", with a large number of professionals from many Ukraine?s leading mining research centers, has developed a research and design work program that includes the following principal stages: 1. Analyzing geomechanical conditions of combined mining of magnetite quartzite and rich ore deposits; determining mechanisms of moving of rock strata underworked by underground mining and places of hazardous area monitoring. 2. Investigating anthropogenic factor influence on the safe state level of rock strata underworked by underground mining (laboratory studies). 3. Developing processing techniques for continuous remote monitoring of rock mass in areas of underground cavity influence. 4. Modeling the state of rock mass based on results of pilot GIS hardware measurements. 5. Developing an expert diagnostics system for rock mass state in areas underground void influence. 6. Experimental investigation and testing the GIS, its improving for efficient application. After testing the pilot GIS it is supposed to be implemented at all mining enterprises as an integral part of iron ore mining and processing technology in the Krivbass area.

Aug 1, 2013