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By Shallesh K. Patel, Richard M. Powers, Patrick Zhang

Perceived environmental impacts from flotation reagents used in the phosphate industry have been of concern for nearly a decade. A research program was initiated to determine the distribution, fate, and consequences of flotation reagents (fatty acids, fuel oils, and amines) within the environment. Therefore, laboratory investigations of biodegradation and soil attenuation of the reagents were conducted along with field flotation mass balances and groundwater investigations in clay settling, sand tailings, and undisturbed areas. Sample analysis and a reagent mass-balance model indicated that most reagents are distributed in clay settling and sand tailings areas. Groundwater analyses showed no fatty acids or amines in any of 19 surficial or intermediate aquifer water samples. In contrast, fuel oils were detected in the surficial aquifer at all sand tailings areas in concentrations ranging between 8.5 and 0.5 mg/L. Fuel oil was also detected in trace amounts (0.6 mg/L) in one intermediate aquifer well located in an active sand tailings area. All fuel oil concentrations detected were very low and, coupled with a biodegradation rate of approximately 10% per month, all concentrations should be within reference levels in six months. Based upon the results of this study, use of flotation reagents in the beneficiation process of the Florida phosphate industry present no long-term threat to the environment.

Jan 1, 1999

By J. R. B. Lima

The present work emphasizes the selection in the separation of the apatite/calcite by the direct anionic flotation versus the double flotation, with a reverse second stage of the Jacupiranga phosphate ore. The double flotation would allow the obtaining of two concentrated solutions: one of them mainly constituted by a calcium carbonate material (CaCO3) and the other one, phosphatic (apatite). The calcium carbonate concentrated solution is used for the production of cement. The presence of phosphatic material in the calcium solution is not desirable, phosphor being a harmful element to cement. On the other hand, smaller quantities of calcite in the phosphate concentrate would represent a substantial economy in the processes of production of phosphated fertilizers. These processes make use of sulfuric acid to the solubilization of the apatite and the presence of calcium material consumes acid. Also that, when carbonates are solubilized, unwanted products are formed resulting in losses in the process and diminishing the quality of the fertilizer produced. These characteristics are discussed in the paper and are compared to another Brazilian phosphate ore, the reverse route of which can be considered more adequate. The results are discussed according to recent discoveries, and special emphasis is given to the use of corn starch and its crucial role in promoting the selection in the direct flotation process.

Jan 1, 1993

By P. Eng. Daniel Kelly

INTRODUCTION The Astoria property is located in the prolifically mineralized Abitibi greenstone belt and is one of the most advanced projects presently under development by Yorbeau Resources Inc. This property, which hosts the Astoria gold deposit, is located in the southern part of Rouyn township, Abitibi area, Quebec, 4 km south of the city of Rouyn-Noranda (Figure 1). The Astoria deposit has been the subject of underground development for over a half century, beginning with Granada Rouyn Mining Co. in the 1930's and followed by Astoria Rouyn Mines Ltd. in the 1940's. Yorbeau Resources Inc. acquired the property in 1984 and has, since then, conducted numerous exploration programs on this gold deposit. The diluted reserves of the Astoria deposit are estimated at 1,3 million metric tons grading 6,14 grams of gold per metric ton (1.4 million st at 0.18 oz/st). This reserve figure is based on the results of surface and underground exploration carried out from January 1986 to June 1987 and includes ore in the proven, probable and possible categories. This paper is divided into two sections. The first part includes a summary of the geological environment including a description of the gold bearing zones and a short discussion on wall rock alteration. The second part of this paper reviews the underground work and the objective of the ongoing exploration program.

Jan 1, 1988

By Stephen B. Doppler

INTRODUCTION Following the world stock market debacle in October 1987, it would have been foolhardy to expect that securing equity funding in 1988 would be easy. Indeed, major equity financing's for gold mining companies have until recently been few and far between in the weeks and months following Black Monday. As a result, gold bullion loans have taken on an increasingly important role among producing firms in the industry. During 1988, the role of bullion loans has become increasingly complex and controversial. Some observers herald the emergence of a new breed of bullion loans - such as the 1,000,000 ounce loan to Newmont Mining, and the 400,000+ ounce facilities drawn down by Bond International Gold and Placer Pacific - as both increasing the public's awareness of the technique, and representing the dawn of a new age of gold financing. But are these recent loan facilities significantly different than those issued worldwide during the early to mid 19801s? Similarly, observers have voiced concerns regarding the role that gold loans play in the world's bullion markets, specifically in relation to their impact on prices. Have the new generation of mega-loans depressed current and future prices? Has the current surge of bullion loans irrevocably changed the nature of the gold market? Is there an upper limit on the number and size of gold loans?

Jan 1, 1988

By D. W. Fohlen, B. A. Filas

The International Finance Corporation (IFC), the private investment arm of the World Bank Group (WBG), requires all IFC-financed projects to comply with its environmental and social policies and guidelines. IFC's review process involves an environmental and social assessment and the implementation of an Environmental Action Plan (EAP) that will set forth the necessary actions to bring the operation into compliance. This paper provides an overview of the environmental and social policies and guidelines that apply to mining projects and examines how WBG/IFC policies and guidelines are applied to mining projects in developing countries. In addition, it includes a review of the increased emphasis IFC is giving to social issues over the past several years based on the existing WBG policies. IFC’s process for the environmental and social review of proposed investments is briefly discussed. The paper focuses on how IFC emphasis has shifted from the traditional environmental and impact mitigation analyses of a few years ago to the integrated social and environmental awareness, action (EAP), and implementation programs (social plans) required today. Today, IFC's focus is to promote sustainable development by investing in projects that directly benefit local communities and the environment. Examples of these changes will be highlighted by a review of recent investments located in West Africa. The goalposts have not moved, but the rules of the game have become tougher.

Jan 1, 2001

By Michael DiMatteo, Michael D. Gardner, Eric F. Perry, John K. Felbinger, Robert S. Evans

A hydrologically isolated surface coal mine was reclaimed using acid material handling, alkaline addition and ground-water management techniques. Eight pit floor drains were installed during reclamation to intercept ground-water flow in the mine backfill and minimize water table buildup. All drains began flowing within six months of installation. Water quality and ground-water discharge have been monitored for four years after mine closure. A thin water table aquifer about five to seven feet thick has developed in minespoil about 20 to 40 feet thick. Ground-water flow direction is largely controlled by geologic structure and the drains. Median ground- water discharge is about 0.43 gallons per acre per minute, and varies an order of magnitude between wet and dry seasons. About 19 % of precipitation enters the aquifer as recharge. Seven of the eight drains typically discharge net alkaline water. Alkalinity is produced continuously and concentrations are highest during dry periods. Conversely, sulfate and acidity concentrations increase during wet periods as slugs of accumulated acid products are leached. Overall water quality is controlled principally by minespoil geochemistry and added alkaline material. The drains have successfully directed ground-water to a planned discharge area. Without the drains, a ground-water mound was expected to form against a buried highwall and discharge over a large area.

Jan 1, 2000

As noted by D.W. Fuerstenau in his Plenary Lecture at the Conference on Extractive Metallurgy of Gold and Base Metals, Kalgoorlie, Australia, "Com¬minution of solids is surely one of the oldest technologies that, even in this day and age of DNAs, chips and space exploration, continues to challenge our scientific acumen and engineering ingenuity." Thus, the fundamentals of comminution continue to receive a great deal of attention in the literature. This was particularly true in 1992 with the publication of the proceedings from the SME-sponsored symposium, Comminution Theory and Practice. Papers covering topics ranging from liberation to comminution fundamentals to novel size reduction techniques are included in this review. Liberation Liberation continued to be a prime area of research interest, not only in terms of liberation modeling, but also in understanding the basic mechanisms involved in mineral liberation. King (Comminution - Theory and Practice, pp. 3-15) described a method for determining the interphase area between mineral grains. He showed how the mea¬surement of interphase area before and after comminution could be used to determine the presence or absence of intergranular fracture. Lin, Miller and Cortes (Kona, Vol. 7) discussed the use of computed tomography (CT) as a nondestructive means of investigating three-dimensional particle composition. The use of this technique in constructing coal washability curves from CT data was presented.

Jan 1, 1993

By K. E. Hjelmstad

Solution mining operations often encounter difficulty maintaining adequate leach solution flow into the ore formation because of loss of formation permeability near the injection well. Permeability loss caused by swelling and breakup of clays and fine particle migration can often be the cause of the problem. Combined permeability and leaching tests were done in the laboratory on samples of clay bearing ores to evaluate a clay-stabilizing polymer's effectiveness in preventing the problem. Test results indicate that treating the ores with cationic polymers could maintain permeabilities two to five times greater than the long-term permeabilities present in untreated ores. Both alkaline (pH 8.5) and acidic (pH 2.0) leaches were used in the permeability leaching tests. To determine the reasons for the success of the clay stabilizing polymer, clay swelling tests and zeta potential measurements were made on untreated ore samples and on ore samples treated with the cationic polymer. Test results indicate the cationic polymer could reduce the degree of negative charge on fine particles and their tendency to disperse, as well as reduce clay swelling. Test results indicate a potentially beneficial effect on operating parameters such as capacity and injection pressure during leaching, if clays and fines are kept stabilized. This may be done by treating the zone of high fluid velocity near injection wells with cationic polymers.

Jan 1, 1991

By G. Lodewijks

Today most belt conveyors used for the transportation of bulk solid materials are driven in a centralized way with all drives in one location. The dynamics of these systems has been studied since the early seventies of the previous century and are well understood. Compared to the more conventional belt conveyor system with a centralized drive station positioned at the head and/or tail of the system, a decentralized driven layout with drive stations distributed along the whole length of the belt offers a number of advantages. However, to make a decentralized driven configuration a good alternative to a centralized driven, the system designer will have to balance these benefits with the increased complexity. The full potential of a decentralized driven system can only be realized if the right balance is found between the locally applied drive force and the motion resistances occurring along the system. From previous research it was found that in a multiple driven belt conveyor system the most dominant belt behavior occurs in the belt section between the tensioning device and the first drive station. In this paper different possibilities are analyzed to improve this dominant belt response and optimize the starting behavior. This can be accomplished by changing the predescribed start up profile, starting the drive stations in sequence rather then all at the same time and altering the locations of the drive stations.

Jan 1, 2008

By Ronny J. Sadri

Under contract to the Department of Energy, Fluor Mining & Metals, Inc. and Bonner & Moore Associates developed a group of computer models that can be used to simulate single seam dragline operations. These models have been subsequently modified by Fluor for use in multi-seam dragline mining situations. The single seam model analyzes the digging, spoiling, and walking patterns of draglines to identify possible parameter changes to increase productivity. Parameters such as key-cutting, panel width, digout length, and bench height, etc., are analyzed in this process. The models were tested using data from four operating mines. Field demonstrations were performed to correlate computer optimization results with field data. Productivity was greatly enhanced at one mine site by a change in some of the operating parameters. The multi-seam study has as its objective the development of a broad- based mine planning tool which would be used to identify and quantify the different procedures employed in multi-seam dragline mines to increase their productivity. The major problem identified in multi-seam mining is the sequencing of the different stripping and mining operations. The multi-seam model has the same capabilities as the single seam model. In addition, it models up to four seams with three partings per seam. It allows the operation of several draglines at different levels, and analyzes the effect of ramps, rehandling, and ancillary mining equipment.

Jan 1, 1982

By Judith A. Marks, Deane K. Smith, Jan M. Mutmansky, Maria Klimkiewicz

The mechanical mining of coal seams where roof, partings, and floor rock are extracted along with the coal often introduces large numbers of quartz particles into the mine atmosphere. This study concentrates on the quartz properties in situ and in the airborne dust to determine how they are released from the source rock and whether they are fractured by the mining machinery. Three mines using drum-type continuous miners from different geographic areas were sampled to provide a data base. The roof and floor rocks were primarily siltstones containing 5% to 25% quartz measured by the X-ray powder diffraction (XRPD) method. Much of the work presented here is based on the morphologies of the mineral grains determined by the scanning electron microscope (SEM). The study concentrated on particles of 0.2 to 10.0 µm and on particles containing > 75% Si. Mechanically-crushed quartz particles were also examined for comparison purposes. Particle shapes from the airborne samples suggested that fractured quartz particles were rare. Particle statistics also show that the average size of quartz particles in the airborne samples were similar to the average size of all particles. The conclusion is that very few quartz particles from the source rocks are fractured during mining due to their small initial size and the protection of the associated clays.

Jan 1, 1991

By J. Herbst, A. J. Lynch, E. V. Manlapig, G. C. Throne, J. S. Hall, G. Poling

Modelling of industrial sulphide flotation based on data collected in several flotation plants is discussed. A mechanistic approach is used in which it is recognised that flotation is a two stage process with concentration occurring both in the pulp and in the froth. The important features of the model, which is a kinetic model, are – 1. for each particle species there is a range of flotation rates which corresponds to the range of particle sizes, 2. the flotation rates of the liberated gangue particles which have no hydrophobic properties are dependent on the flotation rate of water and are controlled by variables such as the air and frother addition rates, and the pulp level, 3. as an approximation the valuable sulphide particles may be regarded as being present in two groups with high and low flotation rate constants, 4. increase in the addition rate of collector tends to increase the proportion of sulphide particles which are in the high flotation rate constant group. The actual flotation rate of each group of particles is a combination of an "inherent" flotation rate and a flotation rate which is dependent on the flotation rate of water, at particular air and frother addition rates and pulp levels there is a physical limit to the rate at which particles can be transported into the concentrate and this is recognised in the

Jan 1, 1976

By Gian-P. Lozej, Ross Y. Black, Sami S. Maddah

The Zabirah bauxite is a Cretaceous paleolaterite exposed by postTertiary uplift and erosion of the Phanerozoic sequence. The laterite profile, which is preserved in situ, occupies a prominent angular unconformity over a sequence of sandstones, siltstones and mudstones ranging from Late Triassic to Early Cretaceous in age, and is overlain by a Late Cretaceous terrigenous and carbonate package. The profile is known to be preserved over an area of 250 sq km and at depths below the present surface of up to 80 m. The bauxite layer is hard, compact and predominantly pisolitic, with a variety of subordinate, superimposed textures resulting from post-formation alteration. The bauxite minerals are boehmite and gibbsite. Boehmite generally predominates, and the boehmite:gibbsite ratio averages 2:1, with a marked tendency for the proportion of boehmite to increase down the profile. Kaolinite, a major constituent of the profile, is concentrated in two zones, one above and one below the pisolitic bauxite layer. Iron content is variable and bears a direct relationship to parent-rock lithology. Genesis and preservation of the bauxite are due to the favourable coincidence of a number of geological controls of which the most significant are the local structural and sedimentary regimes, the lithology and chemistry of the parent rocks, and the Cretaceous paleogeography of the region.

Jan 1, 1984

By J. Loredo

The region of Asturias, located in the northwest of Spain, has an extensive mining history; coal, gold, zinc, lead, copper, cobalt, mercury, iron, manganese, fluorspar and others have been extracted from the antiquity. In the Asturian Central Coal Basin, the closure of all open pit coal mines and their restoration, the progressive closure of underground coal mines that is happening from the 1980?s, and the restoration of spoil heaps, provides post mining lands for alternative uses. In relation to metallic mining, the abandonment of all mercury mines without restoration in the 1970´s, has left significant quantities of wastes and mining works. More than thirty years later most of them remain without restoration. In these sites the legacy of the historical mining activities is apparent in the form of shafts, galleries and transversals, old mining installations and spoil heaps. Mine wastes have eventually become important Hg and As pollution sources, resulting in a widespread contamination of the surrounding soils and surface waters. Abandoned mines of other metals such as copper, cobalt, iron, etc. and industrial minerals such as fluorspar, have also left a mining legacy to take into consideration. In this context of declining mining areas, some remedial options have been applied to specific areas resulting in alternative uses as pastures, agro-forestry, industry and socio-cultural activities.

Jan 1, 2008

By N. Economou

Temporary local seismic networks were installed in western Crete, in central Crete, and on Gavdos, an island south of western Crete, in order to image shallow seismically active zones of the Hellenic subduction zone. Data acquisition was divided in four campaigns through the years 1996 to 2001. More than 4000 events in the magnitude range between 0.5 and 4.8 were detected and localized. The resulting hypocenter distribution allows the localization of seismically active zones in the area of central Crete from the Mediterranean Ridge to the Cretan Sea. The comparison of the hypocenter distribution and the structure has allowed intraplate and interplate seismicity to be distinguished. A southwards dipping zone of high seismicity within the Aegean lithosphere is found south of central Crete in the region of the Ptolemy trench. Between 20 and 40 km depth beneath central Crete, the Aegean lithosphere appears to be seismically inactive. Especially for the year 2001, 1560 events were localized, by the seismic network installed on Messara, central Crete. Most of the seismic events were located, as expected, in the South region of central Crete. National Observatory of Athens (NOA) maintains a permanent seismic network in Greece. In this work a comparison of the earthquake epicenters obtained from both the NOA network and the BOCHUM-TUC network is presented.

Jan 1, 2006

By David Conover

The El Boleo Copper Project is currently in the final design stages for development of a 3-MM-tonne/yr underground copper mine located in Baja California, Mexico. The nearly horizontal mineralized zones are amenable to exploitation by conventional mechanized coal mining technology using continuous miners, shuttle cars, and belt haulage. The mine design resembles a typical full-extraction coal mining operation utilizing a sequence of mains, sub-mains and production panels. Due to numerous faults, mining will be conducted as several small adjacent mines accessed through adits from large arroyos cutting through the mine area. Up to four seams may be mined in some areas with a maximum overburden depth of about 250 m. The ore zone is relatively weak and plastic, subject to extensive creep over time. The mine workings will pass through areas of historical shortwall mining panels where the ground has flowed into old entries and gob areas, and then reconsolidated. A small test mine was developed to evaluate mechanical cutting performance, roof-bolt anchorage capacities, roof and pillar stability and caving behavior. In-mine measurements were combined with two- and three-dimensional FLAC models to evaluate alternative development and production pillar designs. The paper will discuss the various factors influencing ground stability at the El Boleo project and the strategies employed in developing a suitable ground control design.

Jan 1, 2009

By Paul T. Allsman, Paul F. Yopes

17.1--CURRENT AND FUTURE STATUS OF SURFACE MINING PAUL T. ALLSMAN AND PAUL F. YOPES 17.1.1--CURRENT The history of surface mining essentially is one of mining coal, copper, iron and aluminum ores, of placer mining gold and tin, and of pits and quarries producing clays, gypsum, phosphate rock, sand, gravel and stone. Table 17-1 is a summary of the estimated world and United States production of crude metallic and non¬metallic ores and coal in 1969. It includes estimates of the quantities produced by surface-mining methods. Two-thirds of the 10 billion tons are mined from the surface, ranging from a third of the coal. 57% of the metallic ores, and nearly all clays, stone, sand and gravel. Production by surface methods in the United States, parallels that of the world with one exception: about 90% of the copper and iron ore is mined from the surface, whereas elsewhere only about half the copper ore is surface mined. In Canada, surface mining of the Athabasca tar-sand deposits is a recent large-scale unique operation. In surface mining of coal and, to a lesser extent, metallic ores, much waste is stripped, but in nonmetallic pits and quarries the ratio between waste and ore usually is small. Assuming that the stripping ratio for surface mining in the

Jan 1, 1973

By C. M. Bartley

In world-wide mining circles countries become known by the principal minerals they produce. The production of iron, copper, phosphate and sulphur in the United-States-has-been particularly significant and has provided the base for aggressive developments in heavy industry, agriculture and chemicals. Mention diamonds and gold-and you will think--South Africa; silver-Mexico; nickel and asbestos--Canada. The main purpose of this paper is to point out that potash mast be added to the list of minerals by which Canada is known in the mining World. The potash deposits of western Canada must be classed as a major world source of chemical fertilizer raw material. We believe that they are both the largest and the richest of all known deposits in the world. The most knowledgeable people in the industry avoid making estimates of reserves because even where the arithmetic is correct the total is so large that it appears to be ridiculous. In 1957 Marion Goudie made a carefully qualified estimate of 6 billion tons of recoverable potash above 3,500 ft, and grading 25 per cent K20 or better. This figure can now be increased by the amounts available through solution mining. No one has bothered to estimate how much this is because it is so large that the actual amount is not significant.

Jan 1, 1966

By Atta Ur Rehman, Kwame Awuah-Offei

"Information diffusion potential of a social media user affects how quickly information about a mineral project can diffuse through that user. If management can use social media and network analysis in community engagement programs to understand how fast and how far information will diffuse to communities and followers of particular social media users, it can selectively focus on the most influential users. This article proposes a method to examine the information diffusion potential of social media accounts. The work uses Gephi, an open source software, to extract and analyze data from different Twitter handles to predict their information diffusion potential. The work uses case studies of real Twitter users (e.g. mining news organizations and bloggers) associated with mining to illustrate the approach. The case study results show that there are significant disparities in information diffusion potential that will demand selective attention. This research will help mines develop effective social media engagement strategies.The mineral industry provides raw material for industrial activity to support society (Martens and Rattmann, 2001). Mines have changed from conventional mining practices to sustainable ones because of the negative impacts of mining in the past and increased public awareness (Wang et al., 2016). The concept of sustainable mining is getting mature, as stakeholders (e.g., governments, investors and host communities) are getting more involved in mining projects (World Economic Forum, 2014). The failure of mining companies to address the demands of these stakeholders might result in the failure to acquire a social license to operate (SLO) (Thomson and Boutilier, 2011). The SLO, if granted, is mutually beneficial to all stakeholders. Mines prefer being granted SLO and keeping it to avoid any kind of social unrest due to their operation (Prno, 2013; Moffat and Zhang, 2014). Mining communities can grant different levels of SLO ranging from withholding SLO to psychologically identifying with the project (Joyce and Thomson, 2000; Thomson and Boutilier, 2011).Most of the previous work to understand community perceptions and SLO in mining is generally qualitative (ICMM, 2012a; Thomson and Boutilier, 2011; Prno, 2013; Moffat and Zhang, 2014; IFC, 2014). In particular, there is limited work on how community perceptions change over time due to information diffusion (Boateng and Awuah-Offei, 2017). However, SLO changes with respect to time (Yates and Horvath, 2013), which can result in risks that are not easy to predict. Mine managers and engineers have a desire to understand these changes so as to mitigate these risks (Que and Awuah-Offei, 2014; Que et al., 2015)."

Jan 4, 2018

By D. Tepavac, S. Simmonds

"The high virgin horizontal in situ stress field in the Sydney Basin and its impact on civil engineering projects is a well-known and accepted phenomenon found in significant literature (e.g., Pells, 2013). The prevailing high-stress effects depend on many factors — rock quality, tunnel orientation, proximity of geological features to tunnel crown, size and shape of opening, depth of excavation and stress magnitude. The behavior of the rock mass under high in situ stress conditions can cause stress fracturing and consequent dilation of the tunnel periphery, resulting in rock spalling at the tunnel crown/ invert or raveling of rock blocks on the tunnel sidewall. This type of failure is of a brittle nature and may create construction and safety risks during tunnel excavation, if it occurs behind the excavation face where ground support has already been installed. Therefore, the associated risks need to be managed during construction. This paper presents the design strategy adopted to mitigate these adverse tunneling conditions for the WestConnex Project to-date. Overview of the WestConnex M4 East and new M5 tunnel projectsWestConnex is one of the New South Wales government’s key infrastructure projects. This 33 km (20.5 mile) project aims to ease congestion and connect communities and is the largest integrated transport and urban revitalization project in Australia. It was a key recommendation of the State Infrastructure Strategy released in October 2012. It brings together a number of important road projects, which, together, form a vital link in Sydney’s Orbital Network. These road projects include a widening of the M4 east of Parramatta, a duplication of the M5 East, and new sections of motorway to provide a connection between these two key corridors. The WestConnex project includes a number of stages: Stage 1a: M4 Widening; Stage 1b: M4 East; Stage 2: New M5; and Stage 3: M4–M5 Link. The tunnel design referenced in this paper relates to Stage 1b and Stage 2 of the WestConnex Project (Fig. 1)."

Dec 1, 2018