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By J. B. Hadaway

The operation at Phu Kham commenced design and construction in early 2006 and was commissioned in May 2008. This paper will examine and discuss the project from the inception of flow sheet development and equipment selection, equipment design and manufacture, construction, commissioning and ramp up to full production. The paper will touch on the strategies employed to achieve a short schedule and the efficient use of capital, but with the main emphasis on the grinding circuit. Various challenges during the early years of operation will be discussed including the effect of ore characteristics, including competency, on the performance of the grinding circuit. Actions to overcome these challenges and to enhance performance will also be discussed. Finally, current and future plans to improve the performance of the grinding circuit and the overall plant will be summarised.

Jan 1, 2012

By Alan Jessop

A small group has been set up at the Dominion Observatory, Ottawa, to make a survey of terrestrial heat flow throughout Canada. Terrestrial heat flow is the heat rising from the interior of the earth and escaping at the surface, and is calculated from a knowledge of under-ground temperature distribution and the thermal conductivity of rocks. A small number of diamond drill holes are being sunk for the purpose of measuring temperatures below the surface, but the program is inadequate for a thorough survey. Mines and holes drilled for other purposes are being sought by the Dominion Observatory group to supplement their own drilling program. F ROM January, 1.962, to December, 1964, geo-physicists of many nations will be cooperating in the "International Upper Mantle Project." Unlike tl1e International Geophysical Year, which was mainly concerned with the fluid layers surrounding the earth, the Upper Mantle Project is an intensive study of the solid earth. Canada, with its large land area and extensive Precambrian Shield, is an active participant in the project.

Jan 1, 1964

By W. E. Roscoe

"Mineral exploration properties are those on which an economically viable mineral deposit has not yet been discovered. Such properties are bought, sold, optioned and joint ventured on the basis of their perceived potential for the existence and discovery of a viable mineral deposit. The intrinsic value of an exploration property is therefore based on the exploration potential. One measure of the exploration potential is the amount that can be justified to spend on exploration for a viable deposit.The appraised value method uses a cost approach to value exploration properties. It is based on the premise that an exploration property is worth the meaningful past exploration expenditures plus warranted future costs to test remaining exploration potential. Results of past exploration work are analyzed in order to retain only those past expenditures that are productive in terms of identifying remaining potential. Warranted future costs comprise a reasonable exploration budget to test that potential."

Jan 1, 2002

By P. G. Claridge, G. P. Holmes, M. A. Redfearn

"IntroductionThe purpose of this chapter is to describe current practices in operation and maintenance of flotation circuits in Canadian mineral processing plants. The chapter consists of five sections covering description of equipment, typical flow diagrams, operating practice, instrumentation and maintenance. The approach to this subject matter is intended to be practical in nature, hence no deeply technical treatment of flotation theory will be included.Flotation is an extremely common method of beneficiation of ores. Reasons are the relatively low cost of flotation compared to many other processes, the wide range of minerals to which flotation may be applied and the high efficiency of separation which can usually be achieved. The flotation process as we know it today has been developed within this century and it has had a major impact on the mining industry. While flotation is commonly considered to be important because it provides a relatively simple method of separating minerals in complex ores, the availability of flotation has also made a multitude of mineral deposits in Canada into economically viable mining operations because it allowed production of a concentrate of valuable minerals from the ore. These concentrates could then be transported from geographically remote locations to centraHzed plants for further processing, although the existence of the remote and perhaps small ore body alone would not have justified installation of metallurgical processing plants on site and the grade of ore would not have justified direct shipment of ore.Some of the more common minerals concentrated by flotation are sulphides of copper, nickel, cobalt, iron, zinc, molybdenum, lead and arsenic, as well as non-sulphides such as sodium chloride, potassium chloride, phosphates, silicates, chromite, fluorite, limestone and coal. Precious metals are also recovered by flotation, generally in association with another sulphide mineral."

Jan 1, 1989

By H. Qi, J. L. Feng, D. J. Li

"In the present paper, the characteristics of the granite burst under loading/unloading conditions was studied by means of both laboratory experiment and finite-discrete element method (FDEM). After gaining the mechanical properties of the granite samples under uniaxial compression conditions, the parameters taken as input arguments in the FDEM modelling were then carefully calibrated so as to provide some basic data including Young’s modulus, Poisson’s ratio, uniaxial strength, Lame constants, cohesive strength, and frictional angle for further being used in simulating granite bursts. All the simulating results by the FDEM were basically in agreement with that obtained from the uniaxial compression test and triaxial granite bursts in laboratory, respectively. This study shows that that such computational mechanics of discontinua can be employed to gain powerful insight into the failure mechanism of granite burst, which could also be a useful tool to clarify the collapse mechanism of rock structures in rock engineering design and rock test scheme optimisation. INTRODUCTIONBased on discontinuum state a priori, discontinuous modeling techniques that are commonly referred to as discrete element methods (DEM) treat the material directly as an assembly of separate blocks or particles, which was originally proposed by Cundall (1971) and Cundall and Strack (1979) from the viewpoint of analogous molecular dynamics simulation to better account for and understand the interaction between the blocks. The distinct feature of these formulations is that a constantly changing problem of geometry and contact conditions can be addressed by solving the equations of motion using an explicit time marching scheme (most often in a ‘leap-frog’ format), while updating contact force histories as a consequence of contacts between different discrete elements and/or resulting from contacts with model boundaries (Bicanic 1998). The most notable implementations of DEMs are arguably represented by the universal distinct element code (UDEC) (Itasca Consulting Group Inc., 2013) and the particle flow code (PFC) (Itasca Consulting Group Inc., 2012). Another formulation is the discrete crack framework that is based upon some criteria for an advancement of crack front, which is coupled with extensive local and global re-meshing while simulating by numerical methods such as finite element technique, commonly using fracture theories. Certainly, it is relatively easy to trace the propagation of single crack front governed by some principles of energy release rates (Ingraffea 1997) but tracing of multiple cracks leads to topological and algorithmic complexities. Otherwise, there is no consideration of interacting cracks in these formulations of finite element or enhanced finite element techniques (e.g., in XFEM and ABAQUS)."

Jan 1, 2015

By H. Wotruba, L. von Ketelhodt, M. Kowalzcyk, M. Robben

ABSTRACT Decreasing reserves, water shortages, increasing energy costs, and environmental and social constraints are challenges to the gold mining industry that must be met with innovative machines and methods. This paper introduces the principles of sensor-based sorting and installations that demonstrate the technical and financial viability of the method. The scenarios discussed highlight the potential and advantages of this dry processing technology that requires little infrastructure. Case studies are presented for different ore types using optical- and X-ray transmission–based sorting. Current research is discussed in terms of the potential of near-infrared spectroscopy and X-ray fluorescence sorting for gold applications.

Jan 1, 2013

By F. Awotwe-Appiah, P. Koshy, A. Y. Fosu, J. Dankwah, J. R. Dankwah

Ghana currently exports its bauxite raw without any value addition. Gradual depletion of high grade bauxite (with high alumina content) and the emergence of low grade bauxite (with high iron oxide content) calls for novel and inexpensive ways to recover alumina from these low grade ores. Bauxite users have indicated their willingness to pay 10% to 50% higher for a corresponding reduction in impurities by a similar amount. This project therefore investigates the carbothermal upgrading of the Ghana Awaso bauxite using waste polypropylene as reductant in a locally designed gas-fired furnace. Composite pellets of low grade bauxite sample (assaying 45% Al2O3) containing pulverised waste polypropylene were formed, oven dried, placed in fireclay crucible and fired for 30 minutes. The magnetic fraction after reduction was separated by a Low Intensity Magnet and weighed. It was observed that up to 97% of the iron oxides (occurring as hematite and goethite) could be separated into the magnetic fraction as magnetite leaving a nonmagnetic fraction with over 98% Al2O3 as opposed to the 45% Al2O3 in the as-received bauxite sample. This research direction provides yet another simple but effective way for simultaneously upgrading low grade bauxite and recycling waste polypropylene, whilst at the same time decreasing the amount of waste material generated as red mud after the Bayer process.

Jan 1, 2015

By G. Danha, D. Glasser, D. Hildebrandt, N. Hlabangana

"In this work, we apply a method known as the attainable region (AR) technique in order to optimize the milling and leaching process of a low grade gold ore. No work on the application of the AR optimization technique has been done yet on a joint milling and leaching process. The advantage of the AR approach lies in its ability to simplify the optimization problem, as searching over a defined set for the maximum of an objective function is a fairly standard procedure. The objective function we selected was that of optimizing a linear function of the value of the recovered material minus the cost of both milling and leaching. Using the three variables (milling time, leaching time and recovery), we constructed a 3D plot and used it to obtain all the possible recoveries from the different milling and leaching times. The optimum for our chosen objective was then found by overlaying a contour plot of the objective function on the 3D plot. Our results show that the optimum was obtained at 90 % recovery with a profit value of 600, milling time of 30 minutes and leaching time of 1750 minutes.INTRODUCTIONAfrican countries are facing a general increase in demand for electrical power. In South Africa, the demand is now surpassing the supply from ESKOM, the main electric power provider of the country. This has resulted in load shedding strategies being implemented in many local communities in an attempt by ESKOM to cope with the high demand. A potentially better approach is to propose use of energy efficient technologies in the country’s largest power consuming industry; the mineral processing sector.In mineral processing, milling is the highest consumer of energy. The objective of carrying out milling is not merely to reduce the particle size of the feed material, but also to liberate the constituent minerals that make up an ore. This is done so that valuable minerals can be separated from the gangue, in downstream processes, such as leaching. However, the milling process is generally performed relatively poorly, and at a considerable expense in terms of electrical power utilization. Tomanec and Milovanovic (1994) estimated that milling accounts for more than 50 % of the total power used in the concentration process, but this can rise to as high as 70 % for hard or finely dispersed and inter-grown ores. Apart from being relatively wasteful of energy, the milling process is also inefficient with regard to mineral liberation because of the indiscriminate nature of the grinding force."

Jan 1, 2016

By Joseph J. Larry

In hard siliceous sandstone strata overlying coal seams, roof bolting is often the bottleneck in the coal production cycle. In the past, these strata have been drilled by pneumatically operated stopers. Although slow drilling is cumbersome and uncomfortably noisy, the stoper was the most effective drill in these harder strata. However, because of the (U.S.) Coal Mining Safety Act, which limits noise levels for operating drills, FMC Mining Equipment developed the water-through-the-drill-steel method of drilling high-compressive-strength strata. Although water-through-the-drill steel had been developed earlier, the real impact of wet drilling techniques surfaced when the dual-boom roof drilling machines were installed at the Virginia-Pocahontas Division, Keen Mountain, Virginia, in 1974. This paper covers some of the technical details of the water-through- the-drill-steel design and its application.

Jan 1, 1979

By K. Forsberg, A. Rasmuson, R. Rodriguez Varela, J. Martinez De La Cruz

"This study analyzes the separation of rare earth elements by means of a supported liquid membrane (SLM) with the final objective of recovering REE from an apatite concentrate (Alemrajabi, Forsberg, & Rasmuson, 2015; Mohammadi, Forsberg, Martinez de la Cruz, & Rasmuson, 2015). In this study, the feed phase consists of an aqueous phase containing REE, the membrane phase contains the organic solvent and carrier (D2EHPA and EHEHPA), and the stripping phase is a hydrochloric acid solution. An evaluation of mass fluxes, separation efficiency, and membrane performance is conducted. In order to analyze the suitability of liquid membranes in the extraction of REE, a deeper insight into the mechanisms causing instability is needed. In this study, surface tension is considered as the key factor of Marangoni instabilities and spontaneous emulsification.INTRODUCTIONThe demand of REE and their compounds has increased considerably due to their special physicochemical features that make them crucial elements for numerous high-tech applications, including wind turbines, hybrid cars, mobile phones, and defense technologies. They are also extensively utilized in traditional industries such as nuclear energy, petroleum, metallurgy, agriculture, and textiles (Xie, Zhang, Dreisinger, & Dyole, 2014; Zhang, Wu, Bian, & Zeng, 2014).Solvent extraction is widely used for the separation of REE (Xie et al., 2014; Zhao, Huo, Pan, Li, & Liu, 2014). Di-(2-ethylhexyl)-phosphoric acid (D2EHPA) and 2-ethylhexylphosphonic acid mono-2-ethylhexyl ester (EHEHPA) are two of the most effective extractants for the separation of rare earth elements among organophosphorus extractants (Gupta & Krishnamurthy, 2005). However, the difficulty in stripping loaded D2EHPA extractant, especially for heavy REE, has limited its utilization. Yttrium can be stripped at lower acidities in EHEHPA systems compared to D2EHPA systems (Gupta et al., 2005), but the extraction efficiency is lower. Conventional solvent extraction by mixer-settlers is restricted by its large solvent inventory and loading limits, and suffers from phase disengagement, emulsification, loss of solvent, and flooding problems (Swain, Jeong, Lee, & Lee, 2007). In this context, supported liquid membranes (SLMs) present a potential alternative due to their advantages, being low solvent inventory, process simplicity, low energy and operational costs, great enrichment ratio, and combination of extraction and stripping into one single step. A SLM is a system in which two aqueous phases are separated by an organic liquid membrane suspended in the pores of a porous support by capillary forces. One of the aqueous phases is the feed solution with the solute and the other is the stripping or receiving solution. The solute diffuses through the liquid membrane and then is extracted into the stripping solution (Kislik, 2010)."

Jan 1, 2016

By D. Komljenovic, E. Lafontaine, J. Paraszczak

Availability of the production equipment used in underground mines has a substantial impact on production costs and, thus, on mine profitability. Appropriate collection of pertinent data and information, as well as use of adequate performance measures and their analyses, can help mine operators identify cost-effective opportunities to improve equipment availability. This paper presents study results aimed at reviewing and analyzing means and measures used to quantify equipment availability and its contributing factors (reliability, maintainability and maintenance support) in several Canadian underground mines. It overviews sources, as well as quality and quantity of relevant data and information, and examines performance measures and their definitions, as applied to surveyed mines. Problems concerning data acquisition and meaningfulness of the performance measures are discussed. The paper concludes with some suggestions and recommendations concerning several aspects of equipment availability assessment. Evidence suggests that the latter may become a more useful tool for mine operators in their efforts to reduce production cost.

Jan 1, 2008

By I. L. Sills

Introduction So many minerals and mineral products are used in the glass industry that it would require an unduly long paper to deal adequately with all of them. Only those that go to make up the batch for the more common types of glass will be discussed here, and even with these only, the list is a lengthy one. It is true that for the body of the glass comparatively few materials are required-as silica sand, soda-ash, lime, and feldspar. The others are used mainly to colour or decolorize the glass, or to give it some other desired characteristic, such as high lustre, greater physical strength, or opalescence; but, although they may be present in very small quantities, they are just as in-dispensable to the glass industry as are the main constituents of the batch. Sand Sand is essentially quartz, the dioxide of silicon, Si02. Most glass contains from 71J to 75 per cent silica. Sand for use in the glass industry, or 'glass sand', is obtained both from deposits of unconsolidated material, commonly referred to as 'sand', and from solid rock-sandstone, quartz, or quartzite. For the manufacture of glass, the material must possess a high degree of purity, as noted below, so that, although sand is widespread in most parts of the world, and sandstone, quartz, and quartzite are not at all uncommon, it is only in certain places that suitable deposits are found. At the present time, most of the glass sand used in Canada is imported from France, Belgium, and the United States. The French material, from Fontainebleau, near Paris, is known the world over as a very high quality glass sand. That from Belgium is nearly as good and is lower is price.

Jan 1, 1934

By A. R. Chambers

Malagash received its name from the Indians many years ago on acco.unt of its turbid (milky) waters, although,' the red men did not appreciate the significance of this turbidity, and were, of course, entirely ignorant of the crystal beds of pure salt that lay beneath their feet. The salt lake of the Mississippian, or Lower Carboniferous period, in which these beds occur, was apparently a large one, for there is evidence of its existence at intervals all the way from Sydney, Cape Breton, to St. John, New Brunswick, 300 miles as the crow flies, and there is no knowing what its other dimensions may have been, as much of this horizon is now buried on the one side beneath the waters of the Gulf of St. Lawrence, and on the other underneath the Atlantic ocean. About midway of the area and underlying the counties of Colchester and Cumberland, there occurs a synclinal basin of which the Malagash salt outcrop forms only a small portion of its northern limit. This basin has been described very fully by A. C. Hayes. (1) The operations carried on at Malagash since Hayes wrote his report have brought to light very little in the way of new geological data, except to confirm his pre-dictions as to the probable faulting of the salt strata, and the effect which these faults would have on mining operations.

Jan 1, 1924

By Qin-yong Ma, Jing-shuang Zhang, Bo Han, Pu Yuan

In order to improve the utilization rate of blasthole and blasting effect in vertical shafts, 5 kinds of millisecond blasting model tests with three circle vertical blastholes have been conducted in various delay times with concrete as model material. The blasting effects of millisecond blasting model tests are investigated from cutting volume, cutting depth, and blasting fragmentation, then a reasonable delay time is obtained. In the middle of concrete model, there are 4 blastholes uniformly distributed in the first circle, 6 blastholes uniformly distributed in the second circle, and 10 blastholes uniformly distributed in the third circle. Each blasthole is charged with one millisecond delay electric detonator, and the rest is blocked with stemming. The depth of blastholes in the first and second circle is 180mm, which is 20mm deeper than those in the third circle. After initiation, the blasting cavity is cleaned up, then the cutting volume and cutting depth are measured. Meanwhile, the blasting fragments are gathered and have analysed by function Rosin-Rammler. The test results show that when the inner two circle blastholes initiated simultaneously and the third circle blastholes initiated with millisecond delay, the reasonable delay time is 50 ms. At this time, the cutting volume and cutting depth of blasting model are 3920 cm3 and 68 mm respectively. The fragmentation indexes of blasting fragments, X50 and X80, are 53.2 mm and 74.6 mm respectively. While when all three circle blastholes initiated with millisecond delay, the reasonable delay time is also 50 ms. At this time, the cutting volume and cutting depth of blasting model are 10705 cm3 and 118 mm respectively. The fragmentation indexes of blasting fragments, X50 and X80, are 51.0 mm and 81.7 mm respectively. The researches indicate that for millisecond blasting with multiturn blastholes, the reasonable blasting scheme is multiturn blastholes initiated in millisecond delay and the reasonable delay time is 50 ms.

Jan 1, 2015

By Edward Thomas

Note. - Securing mine roof through consolidating thin or otherwise incompetent strata to increase overall thickness of the immediate roof beam is a new method of roof support and control which has aroused great interest amongst mining engineers and which is now being experimented with and thoroughly investigated by the United States Bureau of Mines. A paper on Roof Bolting, illustrated by photographs and motion-picture films, will be presented by Edward Thomas, of the U. S. Bureau of Mines, at the forthcoming Annual Meeting of the Mining Society of Nova Scotia. In the following pages, Mr. Thomas describes the methods used in roof bolting as illustrated by the photographs that accompanied his paper. The photographs are supplied through the courtesy of the United States Bureau of Mines, whose willing cooperation with miners and mining engineers in Canada is very well known and even more greatly appreciated. This method of publishing Mr. Thomas's paper is adopted because few, if any, Canadian mining engineers have actually seen installations of roof bolts and it is felt that the best possible presentation of such an interesting subject through the medium of the Bulletin will be attained by publication of the photograps over explanatory captions. - Ed.

Jan 1, 1950

By Adam Moore, Ryan Gillespie, Jarrett Quinn, Audrey Walters, Peter Radziszewski

"Vale Long Harbour Processing Plant (LHPP) was designed to process Voisey’s Bay nickel concentrate into finished nickel and associated copper and cobalt products. The plant includes a secondary grinding circuit comprising two Stirred Media Detritors (SMDs) operating in parallel. The ultrafine grinding circuit was designed to process concentrate at a rate of 33 t/h and produce a ground product (P80) of 20 µm to feed the leach circuits. Start-up of the grinding circuit at LHPP was undertaken in December 2014.The objective of this paper will be to describe the design, commissioning, start-up and performance of the secondary grinding circuit with a focus on the two Metso SMD-355-C mills. Following a brief overview of Vale’s LHPP and the SMD technology, the paper will review the design of the SMD secondary grinding circuit from lab tests through to scale-up performance prediction. This will be followed by the results of circuit commissioning outlining some of the issues raised and addressed after which SMD performance will be outlined. Specifically, the SMD circuit grinding performance will be examined since start-up which will include the effect of media size and wear on grinding. Furthermore, impeller wear will be examined by determining initial “shear volume” and worn “shear volume” as well as its effect on mill power and the means to maintain it. The paper closes with a discussion on grinding performance."

Jan 1, 2016

By R. W. Diamond

Introduction THE Sullivan mine and the milling, smelting, and refining operations of the Consolidated Mining and Smelting Company are sufficiently well known to make unnecessary anything more than a very brief account of the events which led up to this Company's branching out into the chemical industry. This development is the result of the 26 per cent sulphur content of the Sullivan ore. Seventy-five to eighty per cent of this sulphur enters the mill tailing, which is stocked at Kimberley. The remainder, contained in the lead and zinc concentrate, is burned off in the first treatments at Trail. Prior to this new development, the sulphur gas was wasted to the atmosphere. In spire of its great dilution with air and discharge from stacks at high elevations above the plant, some damage to vegetation close to the plant was experienced. It had always been apparent that this sulphur should be recovered and utilized if possible, at the same rime relieving, or curing, the smoke nuisance, and constant studies with this in view had, therefore, been maintained. One of the early conclusions reached was that the Canadian prairies would ultimately require large quantities of phosphate fertilizers, as had been the experience of older countries, and that these fertilizers would constitute a large outlet for sulphuric acid which could be made from smelter gases. This conclusion prompted a widespread search for phosphate rock, particularly in British Columbia and western Alberta, with the result that low-grade beds were discovered in the Crowsnest district and to the north therefrom through extensive areas (1). Following these discoveries, an experimental plant was built at Trail for the production of triple superphosphate in order to facilitate field-tests in fertilizing prairie lands.

Jan 1, 1934

By M. Laframboise, M. Buarzaiga

High-pressure acid leaching (HPAL) of nickel laterites has received considerable attention in recent years. High paymetals extraction, good selectivity, and advances in pressure hydrometallurgical technology are some of the reasons for this interest. Falconbridge Limited (Sudbury. Ontario) investigated the HPAL process using both fresh water and seawater for ore processing. The use of seawater resulted in a chloride concentration of 7.8 g/L in the autoclave feed. A test program was developed to study the effect of process water and leach temperature on the leaching behaviour of different ore compositions from the Koniambo deposit in New Caledonia. The work showed that salinity has a major effect on autoclave chemistry. This paper explores the results.

Jan 1, 2004

By Nav Dhadli

Tailings from Oil Sands MiningWhat are they? Challenges Solutions Regulatory Environment Definition of the AFD Tailings Treatment Process 2010 AFD Pilot/Demonstration ProgramTechnical challenges Performance and Results Next steps Oil Sands Industry Collaboration on Tailings Technology TAILINGS ?WHAT ARE THEY? Mixture of remaining water and solids following bitumen extraction process Composed of water, sand, silt, clay, small amounts of hydrocarbon (bitumen, solvent, and asphaltenes) A necessary part of production in excavation of oil sands and removal of bitumen

May 1, 2011

By E. E. Mason

THE Myrtle group of mining claims is situated on Barkerville mountain in the Cariboo mining district of British Columbia, west of the old mining town of Barkerville. An 1,800-foot adit, known as the Shamrock tunnel, was driven in 1935-36 from the Barkerville road and in the general direction of the Myrtle group. It was proposed to enlarge this adit to more convenient section, extend it 2,500 feet int0 Myrtle ground, and from there drive a main entry 3,000 feet along the length of the group. Several laterals were also to be driven off this main entry as part of the tunnel schedule. It was thus originally proposed to drive 5,500 feet of new adit and 1,800 feet of laterals, a total of 7,300 feet of new work. Work was commenced with a bulldozer on April 21st, 1941, cutting a bench on the hillside for a plant site. The power plant was ready for operation on August 8th. Slashing and re-timbering of the old adit rook longer than was expected. It was found that 57 per cent of the length required timbering, chiefly by fore-poling, and there was also trouble in several sections with swelling ground. First round in the new face was taken on September 17th, when a 2-shift daily schedule was commenced. Due to delays in delivery of electrical equipment, it was not possible to add the third shift until November 14th. From then on, a 3-shift daily schedule was maintained with the exception of holidays and fortnightly change Sundays until August 1st, 1942, when shortage of labour caused the dropping of a shift. All work was suspended on August 14th. The ground through which the tunnel passed was such that the driving was often interrupted by the need of protective timber at the face. Further, crews were continuously employed timbering behind the face, and in maintenance of timbered sections in swelling ground. Roughly 980 feet of the new workings are now timbered, about 21 per cent of the total.

Jan 1, 1942