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By I. S. Parrish

The Sullivan Mining Group has been exploring the mineral deposits of the Mount Pleasant area of southern New Brunswick since 1967. Sullivan geologists have logged over sixty miles of drill core, mapped over five miles of underground workings and studied numerous surface exposures. Several mineralized zones have been defined and two higher-grade porphyrytungsten bodies delineated. Within these bodies, wolframite occurs as disseminated specks and grains up to one-half inch in diameter. The host rock is a brecciated rhyolite porphyry that has intruded quartz-feldspar porphyry of Mississippian age . The host rock is itself intruded by an acid porphyry called transition rock and is underlain by a microgranite. The mineralized zones, host rock, transition rock and microgranite are all thought to be derived from the same magma, and to represent progressive fractions from that magma.

Jan 1, 1978

By J. Keith Haddock

"IntroductionThe Bienfait Mine is operated by Bienfait Coal Company Ltd., one of the Luscar Limited group of companies. Situated 5 km southeast of the town of Bienfait, Saskatchewan, it can produce 2.0 million tonnes of lignite annually in addition to 158,000 tonnes of char from a carbonization plant located on the property. Geology The economically mineable coal seams of the Estevan area are found in the Ravenscrag Formation. The lignite-bearing sands, silts and clays were deposited in Early Tertiary age, in an inland sea centred in the Williston Basin of North Dakota. The top of the Ravenscrag is an erosional surface, overlain by Tertiary or Quarternary sands and gravels or glacial till. The regional structure is a gently plunging syncline which dips to the southeast at about 0.3 degrees. There are minor undulations in the Bienfait area which are due to differential subsidence during deposition. Sporadic faulting is probably a result of glacial pressures, and preglacial and glacial channels are responsible for washout zones and the abrupt irregular subcrop found in the area. There are two economic coal seams in the Bienfait area, an uppe; seam locally known as the Roche Percee, and a lower seam, the Estevan. Both seams have been extensively mined since lignite mining began in the area in the late 1800s. The Roche Percee remains only in a small portion of the Bienfait Mine and comprises a very minor portion of the reserves. It averages 1.74 m thick under 8.1 m of overburden. The till rests on top of the Roche Percee and due to weathering the seam is generally of poorer quality. The Estevan seam comprises the majority of reserves at Bienfait. The main seam which is being worked on consists of an upper bench averaging 2.75 m, a carbonaceous parting of 0.21 m, and a lower bench of 0.92 m. Overburden depth above this seam varies from 21.0 m to 38.0 m."

Jan 1, 1985

By Xiao min Zhou, Yan Xu, Hongzhen Liang, Xiaonan He

"With the increase of shaft excavation depth, the thickness of the shaft lining increases sharply. It is difficult to reduce thickness of lining effectively by improving high-strength concrete performance. The concept of the New Austrian Tunneling Method (NATM) is that surrounding rock plays a certain role in tunnel support. The solution should be to find the correct relationship between shaft lining thickness and rock strength, which is related with the interaction between the surrounding rock and concrete lining. The plane strain mechanics model is introduced to calculate lining thickness. Shaft lining design of Cixi Colliery in China is completed with the mechanics-based method proposed in this study. The lining design is verified through numerical simulation and field monitoring. The simulation results show that the maximum mises stress is located at the inner edge of the shaft lining. The increase of lining thickness cannot effectively reduce concrete grade. The monitoring results indicate that a lining design thickness of 900mm with C60 concrete, is safe and reliable in the shaft over 1000metres.This analytical design method can well be referenced in similar deep shaft projects.INTRODUCTION The New Austrian Tunneling Method (NATM), thought to have helped revolutionize the modern tunneling method, is the most extensive design philosophy and construction principle in today's tunnel engineering. It began to attract attention in the 1960s based on the work of Ladislaus von Rabcewicz, Leopold Müller, and Franz Pacher in Austria[1]. NATM was originally developed for tunneling in depth and in high situ-stress conditions in the Alps. The history of sequential excavation was reviewed, which highlights the progress of tunnel design and construction in Europe after NATM[2]. Structural conditions were introduced into the equilibrium of tunnels in NATM, and the additional force was estimated to stabilize the excavation of the tunnel[3].From the perspective of applied mechanics, there was no accuracy theory to explain the interaction between the tunnel structure and the surrounding ground. Numerical calculation is an effective means to study the basic mechanism of tunnel excavation[4].Based on two-dimensional modeling approaches in the past, such as NATM and other derivatives, a three-dimensional model was studied to"

Jan 1, 2019

By Ben C. McLellan, Philip J. Bangerter, Andrew Murphy, Glen D. Corder, Damien Giurco

Sustainability now forms a critical part of metallurgical plant design. In addition to compliance with requirements and corporate principles, design engineers must also consider how community and societal responses to the metallurgical industry affect the way they design and build plants. Three broad areas to consider are: the design engineer’s contribution to sustainability through the design process and the relationship to the social license to operate (SLO)—the unwritten license communities give companies to safely and responsibly operate the plant and equitably share benefits; the realization of sustainability goals through methodologies emerging in the design activities; and the integration of design frameworks into a contemporary project design context and its investment objectives. This chapter explores sustainability in metallurgical plant design in the context of SLO, design tools and frameworks, and community and societal influences.

Jan 1, 2015

By F. L. Pellet, S. Maiolino

"The determination of rock bolt contribution to reinforced joint shear strength is still a challenge, especially for assessing reinforced rock mass stability. For this purpose, several experimental studies have been performed during the last decades, mostly on small scale rock joint and bolt specimens. However, to accurately assess the rock bolt contribution, scale effect has to be accounted for. For this reason full scale lab tests are required as an alternative to in situ tests for which boundary conditions are more difficult to control.In this paper the results of an experimental program carried out with a large shear box, dedicated to test bolts in full scale conditions is presented. Different rock bolt diameters and different rock bolts inclination with respect to the shear plane were tested Experimental results were satisfactorily compared with an analytical model which is able to compute the contribution of the rock bolt to the shear strength of the joint as well the associated displacement of the joint. These conclusions allows us to validate the model in order to help the designer of reinforced rock engineering structures, such as slope or underground openings, to precise the optimum installation of rock bolts. INTRODUCTIONFully grouted rock bolts are commonly used for rock masses reinforcement to ensure the stability of rock slopes and underground cavities. For this purpose, the determination of rock bolt contribution to reinforced joint shear strength is of the utmost importance. During the last decades, several experimental studies have been performed to investigate the behavior of bolted rock joint. For obvious reasons, almost all the experiments were achieved on small scale bolted rock joint specimens (Bjurström, 1974; Azuar, 1977; Dight, 1983; Egger & Fernandes, 1983; Schubert, 1984; Spang & Egger, 1990; Egger & Zabuski, 1991). These studies made it possible to assess the influence of different parameters such as the bolt’s diameter, the number of bolts, the angle between the bolt and the joint, the nature of the rock, the friction and the dilatation angle of the joint. However, to accurately assess the rock bolt contribution, scale effect has to be accounted for (Vallier et al., 2010). For this reason full scale lab tests have been performed as an alternative to in situ test for which boundary conditions are more difficult to control."

Jan 1, 2015

By M. Pawlik, E. Arinaitwe, V. Ferrera

A series of flocculation tests were performed on dilute quartz suspensions with the use of five polyacrylamide-based flocculants of similar molecular weights but of different degrees of anionicity. The tests were performed as a function of ionic strength and pH. The macromolecular conformation of flocculants in solution was assessed through intrinsic viscosity measurements under the same physicochemical conditions as those of the flocculation tests. It was generally found that the flocculating efficiency of the polyacrylamides correlated with their ability to coil or stretch in solution. Polyacrylamides with the degrees of anionicity on the order of 10-18% showed the highest flocculating efficiency in terms of the settling rates of the flocculated solids and the residual turbidity of the resulting supernatant. At the same time, these most effective flocculants were also found to exhibit the greatest tendency to coil and stretch in solution. This result suggests that the flocculating power of a flocculant is determined not only by its ability to adsorb onto (and bridge) fine particles but also on its ability to conform to the size of the resulting floes.

Jan 1, 2009

By W. F. MacIsaac

"The large low-grade Copper Mountain deposit is located in the northern portion of the Gaspé Cooper Mines property. It is approximately 1 mile north of the Needle Mountain deposit. The orebody outlined to date lies in the top 1,000 feet of the Grande Greve formation. Chalcopyrite occurs in association with pyrite and quartz in small veinlets and numerous fractures. The deposit is immediately adjacent and parallel to a quartz-feldspar dyke and may be associated with a nearby porphyry stock. Stratigraphy, alteration and structure appear to have played an important role in ore deposition."

Jan 1, 1969

By J. N. Brooke

"This paper deals with the training of the mining and mineral engineer and the role that these professional people must play in their company environment, particularly in relation to management.THERE IS SOME CONCERN in the mining industry that the numbers of engineering graduates attracted to it and the academic training that these people have received is inappropriate. Evidence for this is:1. -The meetings and studies initiated by the various mining engineering societies to discuss:(a) attracting students and graduates to the industry; and (b) the appropriateness of the present academic training for the needs of the industry."

Jan 1, 1968

By A. R. Harrington

BEFORE discussing some of the technical aspects of the steam generating plants of Nova Scotia Light and Power Company, Limited, it might be of interest to go back through history and see the development of steam generation in this public utility. Back around 1902 Nova Scotia Light and Power Company, Limited, had three slide-valve engines in-stalled at its Water Street, Halifax, generating station for a total capacity of 1,800 kilowatts. The plant remained at about this size until 1910 and in 1911 a 2,000 kilowatt steam turbine was installed to raise the total capacity of the plant to 3,800 kilowatts. In 1916, a 3,000 kilowatt turbine was installed and one of the slide-valve engines was removed to make a total plant capacity of 6,200 kilowatts. The total demand in the Company's service 8rea was at that time 4,000 kilo-watts.

Jan 1, 1958

By Donald L. Mordell

Introduction A very large part of the world's fuel resources are in solid form, as various grades of ?coal, but an increasing proportion of fuel demands on this Continent and else-where are having to be met by liquid fuels. Convenience and, in many cases, cost weigh heavily in favour of the liquid: fuels, and there are many fuel burning applications where the use of coal would be impractical, such as for automotive or air transport. By extrapolating the present trends one might conclude that, in future years in Canada and the United States, coal will be used only in a few power stations close to coal fields. If such a state of affairs should arise, it will obviously prove embarrassing to those accustomed to make their livelihood from the winning and marketing of coal, but it is perhaps not so obvious that it must also prove an embarrassment to the nation. The major reasons for this are two in number. Firstly, if present coal production is to be replaced by oil production, a large capital expenditure is necessary, which must inevitably be paid by the consumer; and secondly, in times of emergency, large amounts of oil fuels are required for military purposes which cannot be achieved with solid fuels. It is obviously unwise, therefore, to discontinue the use of coal for those non-military jobs that it can do. If we examine the major fuel markets we find that there are three: Domestic heating Steam generation Transport by air, sea, and land For domestic heating, the extreme convenience of oil, in spite of its greater cost, has captured much of the coal market.

Jan 1, 1952

"The ventilation-related risks from mines with elemental sulphur include dust explosions, spontaneous combustion with emission of heat and toxic sulphur dioxide or hydrogen sulphide gases, reactions with nitrates, corrosion, acid water, and pyrophoric reactions with naked iron or other metals. Elemental sulphur will form explosive mixtures in air at lower dust concentrations and at lower ignition temperatures than coal or sulphide dusts. Potential controls include primary ventilation circuit design, control of dust deposition and static discharges, enclosing steel surfaces, inert stone dusting, FRAS ducting, humidifying the air, alternate stench gas, self-contained self-rescuers with goggles, careful siting of underground infrastructure, controls on explosives formulations and procedures, mining method selection, controls on surface temperatures and protection of equipment, careful materials selection for ventilation seals and changes to worker clothing and training.INTRODUCTIONSulphur (“Brimstone” in biblical times) is one of the world’s most important industrial feedstocks and is used in a wide range of chemical processes and industries. Until the early 20th Century, most of the world’s production of sulphur came from ‘conventional’ underground mines in Sicily (Demetra produzioni, 2006; Bellia, 2006). This was a hazardous activity. The Frasch solution mining process replaced traditional underground mining of sulphur until the late 20th Century. Most of the world’s production of elemental sulphur is now as a by-product from sour gas produced in petroleum refineries and natural gas installations (Anon, 1993). As such, there is considerable experience in understanding and managing the hazards of elemental sulphur in chemical plants and surface transport.Whilst rare, underground mines with high elemental sulphur contents (as a gangue mineral) create an unusual range of mine design and operational issues, including many ventilation-related ones. The key hazards from elemental sulphur include: primary and secondary elemental sulphur dust explosions, fires and burning (with emission of heat and sulphur dioxide or hydrogen sulphide gas), reactions with nitrates used in explosives, corrosion of steel and other metals, generation of acid water (especially at higher water temperatures), and pyrophoric reactions with naked iron (e.g., ground support, ladderways or underground fixed plant) or other metals including silver and copper (e.g., used in electrical components and equipment)."

Jan 1, 2019

By G. M. Ritcey

The recovery of copper from low-grade solutions res ulting from dump leaching is well known, whereas the recovery from highly concentrated copper solutions has not been practiced. This paper discusses the use of Ashland Chemical's Kelex 100, a substituted quinoline, for the recovery of copper from solutions resulting from leaching copper-nickel concentrates. A flow sheet is described, and an economic comparison shows Kelex 100 to be superior to either the LIX 64N or LIX 70 reagents of General Mills for the recovery of copper.

Jan 1, 1973

By H. A. Halupka, I. A. Mozer

"At its plant in San Juan, Peru, Marcona Mining Company operates two grate pelletizing furnaces for the agglomeration of 3.5 million long tons of magnetic concentrates annually. Line One, installed in 1963, was built by Lurgi as a downdraft process furnace utilizing a furnace fan for the recuperation of hot gases from the cooling zone. This line was modified in 1966 to include both updraft drying and downdraft drying, and the original roof burners were converted to side-wall burners. Line Two, a Dravo-Lurgi furnace with an annual capacity of 2.4 million long tons, was built in 1966. This line, in contrast to the modified Lurgi furnace, employs direct recuperation of hot gases from the cooling zone and utilization of process gases from the firing zone for updraft drying.At its plant in San Juan, Peru, Marcona Mining Compa-ny operates two grate pelletizing furnaces for the agglo-meration of 3.5 million long tons of magnetic concentrates annually. Line One, installed in 1963, was built by Lurgi as a downdraft process furnace utilizing a furnace fan for the recuperation of hot gases from the cooling zone. This line was modified in 1966 to include both updraft drying and downdraft drying, and the original roof burners were converted to side-wall burners. Line Two, a Dravo-Lurgi furnace with an annual capacity of 2.4 million long tons, was built in 1966. This line, in contrast to the modified Lurgi furnace, employs direct recuperation of hot gases from the cooling zone and utilization of process gases from the firing zone for updraft drying. 5 per cent increased capacity, 30 per cent lower fuel oil consumption, and approximately 400 per cent reduction in grate bar and pallet corrosion. Firing of the pellet bed was improved by conversion from roof to side-wall burners. This modification also permitted utilization of monolithic refractory in place of pre-fired shapes, thereby improving over-all furnace availability and reducing refractory stock requirements from 154 different shapes to 18.Data are presented to compare operating performance of the Dravo-Lurgi furnace and the modified Lurgi furnace. These data show 30 per cent lower fuel oil consumption and 10 per cent higher capacity per unit grate area for the Dravo-Lurgi furnace, which also averages higher availability due to greater operating flexibility."

Jan 1, 1970

By Lesley Hymers

First Nations Natural Resources Youth Employment Program PDAC Mining Matters ? Charitable organization ? Provide education to students, teachers, and the public about rocks, minerals, metals, and mining ? Provide current information and offer exceptional educational resources that meet provincial Earth science and geography curriculum expectations First Nations Natural Resources Youth Employment Program ? Provide instructional development workshops for educators who are teaching Earth science and geography ? Since 1994, reached more than 400,000 students, teachers, industry representatives, and members of the public

May 1, 2009

By D. C. R. Espinosa, P. Aliprandini, J. A. S. Tenório, M. M. Jiménez Correa

"Nickel and cobalt are the main value metals in nickel laterite ore. Cyanex 272 is an extractant used to separate nickel from cobalt present in leach solutions. Previous studies demonstrated the extraction of cobalt, magnesium and manganese at pH 5 using Cyanex 272 as extractant, while nickel remained in aqueous solution. However, it is difficult to separate cobalt from a solution containing magnesium and manganese. One possibility to change the metals’ behavior during the solvent extraction process is to change the mixture of extractants used. In order to study the solvent extraction of cobalt from a solution containing manganese, magnesium and nickel, a mixture of two extractants was investigated. Cyanex 272 (CY) and Versatic 10 (VC) were selected as extractants in the organic phase. The extractant concentrations used were: 20% CY; 15% CY, 5% VC; 10% CY, 10% VC; 5% CY, 15% VC; and 20% VC. In all cases, kerosene was used as a diluent, at 80 vol%. The synthetic leach solution used in this study was prepared according to the composition of a typical nickel laterite leach solution. The pH value of the solution used was 5, and the aqueous/organic ratio used in solvent extraction testwork was 1/1. The study has shown that the composition of the organic extractant mixture did not increase cobalt separation.INTRODUCTION Sulfide and laterite deposits are the main sources of nickel. However, production from nickel sulfide ores has been decreasing over the years, relatively speaking, increasing the focus on the exploitation of laterite nickel ores (McDonald & Whittington, 2008). Laterite ore deposits are found in tropical and subtropical regions. A characteristic of laterite ores is the presence of a complex and heterogeneous mixture of metals (Crundwell, Moats, Ramachandran, Robinson, & Davenport, 2011; Georgiou & Papangelakis, 1998; Gupta, 2003; Kesler & Simon, 2015; Moskalyk & Alfantazi, 2002; Oliveira, 1990). Nickel concentrations in laterite ores are typically 1–2% (Dalvi, Bacon, & Osborne, 2004)."

Jan 1, 2017

By L. Tafaghodi, S. Sarbishei

"Following the depletion of nickel sulfide ores, laterites are considered as one of the main sources for producing nickel and cobalt. One of the primary steps in pyrometallurgical extraction of nickel from laterites involves partial reduction of the ore at temperatures below 1000°C. Studying the kinetics of laterite reduction provides valuable information on reducibility of nickel laterites using coal as a reductant. The present study investigates the reduction behavior of a nickel laterite by thermal gravimetric analysis and differential scanning calorimetry. Non-isothermal reduction tests and X-ray diffraction analysis were performed to find the main reactions that occur during the process. The kinetic parameters were calculated by Coats-Redfern method. The general model of simple reaction f(a)=(1-a)n was used for calculating kinetic parameters.INTRODUCTION Nickel (Ni) naturally occurs in the form of sulfide and laterite ores. Laterite ores are mainly available in tropical regions. Weathering phenomena during millions of years has led to the formation of several layers with specific mineralogy (Butt & Cluzel, 2013). The three main layers downward are limonite, smectite, and saprolite (Crundwell et al., 2011). Although laterites are the most available nickel ore resource (70%), their share in the overall Ni production is limited to 40% (Crundwell et al., 2011). The main reasons for not materializing the full potential of laterites are as follows (Ray et al., 1985): •,Laterite ores contain high water content (free and combined) which in turn results in high energy consumption of the extraction process. •,As Ni is present in the form of solid solution in laterites, physical upgrading methods such as flotation are not effective in increasing the Ni content before the extraction process. •,Extracting Ni from sulfide ores involve exothermic reactions which are beneficial due to decreasing the overall energy requirement of the process, however there is not efficient release of energy in the process of extracting Ni from laterite ores."

Jan 1, 2017

By D. Cronin, A. Plumtree, A. Hosseini

"Crack in corrosion (CIC) linepipe defects are hybrid defects not directly addressed by existing assessment methods. To investigate the collapse pressure of these defects, CIC defects were formed in 508 mm (20 in) diameter, 5.7 mm thick API X52 linepipe. These defects were 200mm long and varied in depth from 3.0 to 3.8 mm. The respective failure pressures decreased from 14.3 MPa for the plain pipe to 7.9 and 6.2 MPa respectively. A standard FAD method was applied to evaluate these defects as equivalent length and depth cracks, predicting the rupture pressure conservatively by 18% on average. However, when assessed as equivalent cracks with a reduced wall thickness corresponding to the corrosion depth, the predicted collapse pressures were more accurate, approximately 14% conservative on average.INTRODUCTIONPipelines are a safe and efficient method for transporting high volumes of oil and gas. However, aging pipelines may experience defects, such as cracks or corrosion. Present approaches include detection, assessment and repair of defects before they may become critical to the integrity of the line. There are different codes and standards for assessing pipeline defects, depending on the type of defect, with API 579 (API, 2000) being the most common code for the assessment of cracks in oil and gas pipelines . Corrosion is commonly assessed using RSTRENG (Kiefner & Vieth, 1989). Other methods such as the Finite Element method and the CPS method (Cronin & Pick, 2002) may be used for crack and corrosion, respectively.At present, there is no specific method or procedure for assessing crack in corrosion (CIC) defects, and as a consequence there is a need to provide an assessment and evaluation of the integrity of these defects in order to determine the requirements for defect repair or hydro line testing. Hence, the goal of this study was to provide guidance for the assessment of CIC defects for linepipe.CRACK IN CORROSION DEFECTS (CIC)Significant amounts of corrosion and cracking are not generally found together (Hosseini, 2010). However, a new hybrid defect including cracking within corrosion (CIC) has been identified in operating pipelines. In this case, cracking coincident with corrosion (schematic shown in Figure 1) provides the motivation for the current study."

Jan 1, 2012

By Hani S. Mitri

Overhand cut-and-fill mining of narrow vein orebodies inevitably leads to the creation of horizontal pillars. As the thickness of the overlying crown pillar diminishes, stresses build up in the pillar. More often than not, this situation causes an increased level of seismicity and possible pillar burst. One well-known strategy to reduce the hazard of crown and sill pillar burst in cut-and-fill vein mining is that of destress blasting. The paper first reviews the methods used for the monitoring and assessment of potential pillar burst in narrow vein cut-and-fill mining. The influence of horizontal stress, mine depth and pillar thickness on stress build-up in the crown pillar is examined through a characteristic narrow vein numerical model. The paper then presents, with reference to three mine case studies, the benefits of destress blasting and the factors affecting its success as a ground control technique.

Oct 1, 2001

In the last five years, new iron ore pellet plants have been built with significantly reduced air pollution levels compared to the older generation of plants. European and American pollution controls are more stringent that in China and Brazil. The recent American plants have successfully employed circulating fluidized beds for sulfur control, baghouses for particulate control, activated carbon injection for mercury and a new design of specialized low-NOx burners.

Jan 1, 2015

By B. Simonian

"The Mount Milligan mine, located in central British Columbia, began operation in September 2013 with a design nameplate capacity of 62,500 dry metric tonnes per day, using a conventional SABC grinding circuit followed by bulk sulphide flotation. Over the last few years, many changes have been implemented in order to debottleneck and optimize the comminution circuit to meet and exceed the nameplate design capacity as well as improve the metal recovery of the flotation circuit. This paper discusses changes, grouped into mechanical modifications, projects, and operational changes. The implementation of these changes as well as ongoing challenges and potential solutions will also be discussed.INTRODUCTION The Mount Milligan mine began production in the fall of 2013. It is a conventional truck-shovel open pit gold and copper mine and concentrator with a 62,500 tpd design capacity copper-gold flotation processing plant. The average head grades for the life of mine are 0.18% Cu and 0.39 g/t Au. At full capacity, the mine produces an average 400 dry tonnes per day of copper-gold concentrate containing approximately 21.5% Cu and 50-60 g/t Au. Current mine life is 21 years. This paper will discuss a selection of the operational, engineering, and administrative changes that have been made at the site since the publication of An Update on Reaching Nameplate Throughput and Continuous Improvement at Mount Milligan (Yue, 2017). PLANT FLOWSHEET CONFIGURATION Run-of-mine ore is crushed through a 60-110 gyratory crusher to a top size of seven inches. Up to 100% of the gyratory crusher product is diverted to the secondary crushing circuit by a moveable gate. The material diverted to the secondary crushing circuit is fed to a vibrating double-deck screen. The screen oversize is placed on a surge pile and reclaimed by four vibrating feeders to feed two 1250 kW standard head cone crushers in open circuit. The screen undersize is combined with the crusher discharge and returns to the conveyor feeding the coarse ore stockpile along with primary crusher product that by-passes the diverter gate."

Jan 1, 2019