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By Tim Langmaid, Steve Skelhorn, Stephanie Robillard, Allen Mitchell

"The Port Mann Main Water Supply Tunnel project provides a critical water main crossing of the Fraser River for the owner, Greater Vancouver Water District (Metro Vancouver). The project consists of two 60-metre-deep slurry panel shafts and a 1-kilometre-long, 3.5-metre excavated diameter tunnel located near Vancouver, British Columbia, Canada. The initial tunnel lining is a precast concrete steel fiber reinforced gasketed segmental lining. The final lining is a 2.1-metre-diameter welded steel pipe. This paper describes the challenges encountered during tunnel construction and the solutions implemented. Key challenges include earth pressure balance tunnelling at up to 6 bar pressure—the highest to date in Canada—a water-crossing without surface access for the majority of the tunnel drive, ground freezing from a river platform for a critical TBM intervention, and boring through cobbles and boulders in dense glacial till. INTRODUCTION Metro Vancouver supplies drinking water to 18 municipalities, one electoral district and one treaty first nation, serving a population of more than 2.4 million residents. Water is collected in three mountainous watersheds to the north of the Greater Vancouver area, in southwestern British Columbia, Canada. To supply the growing demands of Metro Vancouver’s customers, treated water must be conveyed across two significant water bodies: the Burrard Inlet and the Fraser River. The existing Port Mann water main is one of several key links between the watersheds north of Vancouver and the municipalities south of the Fraser River. The Port Mann Main Water Supply Tunnel (PMMWST) is the first of a series of upgrades, to increase capacity, enhance scour protection, and improve seismic resilience. The new tunnel is 3.5 metres (11.5 ft) in diameter and 1 kilometre (0.6 mi) long. When completed, it will contain a new 2.1 metre (7 ft) diameter steel water main that will help ensure the continued, reliable delivery of drinking water to these municipalities, and will more than double the capacity of the existing 1.2 metre diameter main."

Jan 1, 2016

By V. O. Tenorio, J. Puell

"Dump design is critical to effective mine planning in large scale open pit mines. Capital and haulage costs are considerable from early stages and through the life-of-mine as these dumps gradually become immense structures. Delivered mining rates, as well as certain spatial and physical constraints, provide a set of parameters of mathematical and economic relationship that creates opportunities for modeling and thus facilitates the measuring and optimization of ultimate dump design by using programming and empirical techniques while achieving economic objectives. This paper presents a methodology to optimize the ultimate dump design by minimizing its total dumping costs. The methodology consists of the formulation of a generalized model based on the relationship of the main dump parameters, followed by the use of linear programming to find the solution that minimizes the haulage total cost, and finally through a series of iterations, modifies the preliminary solution by projecting it to the topography and creating the ultimate dump design. A case study applied to a waste dump exemplifies this methodology. INTRODUCTION Open pit mine operations move large amounts of material on a daily basis from the shovel faces to the appropriate destination points. Hustrulid et al. identified three major destination places where the material receives downstream treatment after its delivery: mill processing, leaching dumps, and waste rock dumps [1]. The corresponding destination is given by a cut-off grade criteria, ore type, and the possibility of obtaining the maximum metal recovery. Dump leaching technologies have developed substantially since 1975 [2], and have enabled mining facilities to beneficiate low grade sulfide and oxide ores. As a consequence, the number of active dumps have increased since then and the entire mine configuration, which is limited in itself, has changed. The proper location, design, and construction of a mine dump must serve the safety, environmental and economic goals of the long-range mine plans. Therefore, an optimized use of the available surface area in the mine is highly desired."

Jan 1, 2018

By J. Ludden

By Sims Some two years ago we began investigating low coke button bituminous coal for use at our Bound Brook, New Jersey plant as a replacement for anthracite. Since August, 1957 the plant has been operating continously on this coal with the exception of a new 200,000#/hr, cyclone boiler. This study was motivated not from our desire to conduct combustion research, but for the sole purpose of reducing our steam costs, The indications were that the economics were greatly in favor of the use of the bituminous coal. The attempts to reduce the costs have developed some knowledge that has enabled this program to succeed reasonably well as will be discussed later by Mr. Ludden. The production of steam size anthracite is dependent upon either the reclamation of old culm banks or the breakage in the production of the domestic sizes. The anthracite industry has not as yet been able to cut, its mining costs to the point where the production of steam sizes has become a profitable business. This has resulted in two basic problems: (1) A constantly rising price in an attempt to have those sizes carry their share of the cost and, (2) Periodic shortages of supply when the demand is good but the market price prohibits the mining of anthracite to produce those sizes only, These conditions have made the long range forecast appear as though the price would go even higher and/or the supply at times be critically short.

Jan 1, 1958

By M. Ploc

The grinding process in the mining industry has seen an increased throughput to accomplish greater production and lower overall production costs. Up to 8-9 MW, a single motor can be connected to drive the mill through a pinion and ring gear. Above the single-pinion drive limit, the dual pinion approach was developed to allow two drive motors to be used. This allowed the mill input power to be increased to 16-18 MW. Recent developments in clutch and ring gear materials and design are allowing greater input powers of up to 20 MW to be considered. To avoid damage to the ring gear by uneven load sharing between the two motors, it is critical that the two machines accurately share load. This is typically achieved by either drives capable of controlling load torque between motors or using a GE proprietary control system that accurately controls the load torque from each motor.

Jan 1, 2010

By Takuya Tani, Tomoyuki Aoki, Kazuo Saskai

"The authors have proposed a unique methodology in the evaluation of rock mass stiffness for the range of five to twenty meters ahead of the tunnel face, with the use of small diameter inclinometers. The inclinometers are installed at the tunnel crown at a pre-determined constant interval, about one meter behind the face in order to obtain the slight change in inclination angles during tunnel excavation. This method was developed as a daily control measurement such that the geological condition and its possible change ahead of the face could be detected early by monitoring the trend of inclination angles. This paper describes the results of the ground stiffness ahead of the tunnel face evaluated at a mountain tunnel construction site. This stiffness is evaluated automatically and displayed visually by the current system equipped with a result display screen, together with a warning message against a weak zone when detected. 1. INTRODUCTION In a conventional planning of a mountain tunnel, according to the Japanese Standard (JSCE, 2006) seismic refraction surveys from the ground surface are performed and tunnel support patterns are then designed based on the seismic wave velocity. The resolution of the velocity profile estimated by this technique, however, is poor as the tunnel overburden becomes large. The tunnel face is therefore often encountered by unforeseeable fault zones or weak rocks. Such an unpredictable weak zone occasionally causes the collapse of the tunnel face. Clarifying the forward geological information during excavation is hence significant for safe and well-controlled construction. According to the geological conditions ahead of a face, auxiliary methods typified by forepiling and face bolting could be preliminarily prepared for prompt execution. For the purpose of acquiring forward geological information, pilot borehole drilling and seismic reflection methods represented by the TSP (Tunnel Seismic Prediction) or HSP (Horizontal Seismic Profiling) are often applied. Those exploration are carried out near the tunnel face for a couple of days. This often leads to the interruption of excavation procedure and has no small effect on the construction schedule. On the other hand, some forward ground prediction methods in the daily control measurement have been developed e.g. by Schubert et al. (1995). In this method, tunnel displacements in the direction of the tunnel axis are used together with the crown settlements. We have tested their method at a few of our tunnel projects and found difficulty in the evaluation of the forward ground condition due to insufficient resolution of the axial displacement measured by a total station theodolite that we usually use for the tunnel measurement. We have therefore developed a novel methodology of monitoring slight inclination at the tunnel crown near the face, so that the forward ground conditions can be predicted and evaluated as part of a routine measurement procedure."

Jan 1, 2016

By Bruce K. Cantrell, Stephen W. Stein, Kenneth L. Williams, David Hassel, Harvey Patashnick

In June 1992, the Mine Safety and Health Administration (MSHA) published the 'Report of the Coal Mine Respirable Dust Task Group; Review of the Program to Control Respirable Coal Mine Dust in the United States." As one of its recommendations, the report called for the accelerated development of two mine dust monitors: (1) a fixed-site monitor capable of providing continuous information on dust levels to the miner, mine operator, and to MSHA, if necessary, and (2) a personal sampling device capable of providing both a short-term personal exposure measurement as well as a full-shift measurement. In response to this recommendation, the National Institute for Occupational Safety and Health (NIOSH), Pittsburgh Research Center, initiated the development of a fixed-site machine-mounted continuous respirable dust monitor. The technology chosen for monitor development is the Rupprecht and Patashnick Co., Inc. tapered element oscillating microbalance. Laboratory and in- mine tests have indicated that, with modification, this sensor can meet the humidity and vibration requirements for underground coal mine use. NIOSH is continuing that effort by developing prototypes of a continuous dust monitor based on this technology. These prototypes are being evaluated in underground coal mines as they become available. This effort, conducted as a joint venture with MSHA, is nearing completion with every promise of success. The immediate benefit of this effort will be to researchers, regulatory personnel, and mine personnel, by permitting evaluation of specific mining practices to see which expose mine workers to excessive dust levels. Using this information, mine personnel can optimize mining procedures to reduce dust exposure. MSHA and the operators will also be able to use the dust concentration data to judge whether dust plan parameters are adequate to continuously maintaining environmental dust levels below the applicable standard. The second development recommended by the Dust Task Group was a person-wearable version of the continuous dust monitor. It will be a monitoring system designed to provide a measurement of worker exposure to respirable dust, both during and at the end of the shift.

Jan 1, 1997

By D. J. MacKinnon

Smooth, compact, dendrite-free, 24-h zinc deposits have been electrowon from zinc chloride electrolyte using a diaphragm cell. The cell consisted of sealed anode compartment con- taining DSA anodes which were separated from an open cathode compartment by Dynel cloth membranes. Fresh electrolyte was fed to the cathode compartment where zinc deposition onto an aluminum cathode was aided by air-sparging. The catholyte passed through the diaphragm into the anode compartment from which chlorine gas and spent anolyte were withdram.

Jan 1, 1980

By Patzen Wu

Taiwan is located in the orogenic belt of island arcs on the western rim of the Pacific Ocean. The structure of the Taiwan coal fields is much complicated as a result of active Cenozoic orogenic disturbance in Plio-Pleistocene time. The abundant faults and folds have created poor structural conditions of the coal seams and some peculiar safety problems in mining however, the domestic coal still played an important role in the economic development of Taiwan for the years before 1968. Because of increasing mining depth and a decreasing number of miners, the coal production dropped from nearly 5.1 million metric tons in 1968 to 2.45 million metric tons in 1981. There were 173 small active coal mines and about 22 thousand miners in 1981. The coal mining in Taiwan has a history of more than one century. Specific efforts have been undertaken in solving major coal mine safety problems such as gas outbursts, bad roofs and weak floors, difficulty in ventilation due to deep underground mining, spontaneous combustion etc. We have thus acquired much helpful experience which, we deem, is worth reporting at this meaningful meeting.

Jan 1, 1982

By John V. Beall

A completed feasibility study executed by an independent agency can benefit a company in two ways. Inside the organization, it verifies the project staffs ideas and their concept of the facility. Outside the company, it can be utilized to obtain equity partners, debt financing, and other forms of credit. It is advisable to bring in a project execution contractor for the feasibility study. A project execution contractor is able to work with engineers to develop the project concept, process flowsheet, and best utilization of the site. By getting an early start on understanding a company's policies and working methods, a project execution contractor saves the company money since it does not have to go through the educational buildup twice. The contractor is a specialist in putting together a bankable document that can be taken to a financing source. It answers all the agency requirements on the first pass. In addition, the contractor can advise an owner on likely financing sources since he works on the worldwide market every day. A less obvious advantage of including the contractor in the study and predevelopment buildup stages is the importance of coordinating finance and technical input. The financing source influences equipment specifications, procurement, logistics, project schedule, cash flow, and liquidity. There are many surprises in store for any manager of a large international project involving worldwide financing and purchasing. The job does not have to be made more difficult by bringing in a contractor after all predevelopment steps are taken. The contractor can still work if the predevelopment steps have been done, even if he does not agree with them. But early contractor involvement is the preferable solution.

Jan 10, 1980

By R. F. Korcak

There exists a wide array of industrial by-products that can be shown to produce beneficial responses in the soil/plant environment. These materials range from clean coal technology residues produced in the generation of electric power, particularly those high in gypsum, to mineral 'fines' produced by the aggregates and crushed stone industries. A number of these materials will be examined in relation to potential nutritional interactions in soils and crops with emphasis on trace elements. The significance of utilizing these materials in agriculture as a component of sustainable agricultural systems will be discussed.

Jan 1, 1995

By V. K. Srivastava, T. Gupta, T. Ghosh

"In recent years, the demand for rare earth elements (REEs) has grown due to increasing demand and global supply shortage. The supply deficit of these critical elements has encouraged the search for new sources, with coal and coal byproducts as possibilities. Coals from certain parts of the world can be rich in REEs and can approach a total concentration of 1,000 ppm. Two Alaskan coal samples, from Healy and Wishbone Hill, were investigated for the effects of density and particle size on REE concentrations for three selected size fractions, and flotation tests were conducted on finer fractions. Additionally, bottom ash and fly ash samples from a power plant were examined for their REE concentrations. The results show that the upgrade potential for REEs on an ash basis from a whole-coal basis ranges from 2:1 for the Wishbone Hill samples to 4:1 for the Healy coal samples. Flotations of the finer fractions of the two coal samples, conducted under similar conditions, revealed higher concentrations of REEs in the tailings. Both coal samples had comparatively higher contents of light-group rare earth elements (LREEs) than heavy-group rare earth elements (HREEs). REE content trends for the power-plant products on an ash basis indicate that fly ash has slightly higher concentrations of both LREEs and HREEs than bottom ash. IntroductionRare earth elements (REEs), also known as rare earth metals, and their compounds are vital components in industrial, automotive, petrochemical, defense and medical applications. Dysprosium in combination with other elements is used in laser materials and nuclear control applications. Neodymium is present in magnets that are used in the manufacture of wind turbines and hybrid cars. Europium, terbium and yttrium are used in devices that have visual displays such as computer screens and laptops (Haxel, Hedrick and Greta, 2002; Bunzli, 2013). REEs pose fewer environmental problems of disposal and recycling than their conventional heavy metal counterparts (Haxel, Hedrick and Greta, 2002). They are key materials for radar systems, avionics, modern national defense and satellites (Cammarata and Sieradzki, 1994; Hedrick, 2010; Martin, 2010; Szumigala and Werdon, 2011; Cordier, 2011; Bunzli, 2013). REEs are often classified into light-group rare earth elements (LREEs) and heavy-group rare earth elements (HREEs). This classification is primarily based on the electronic configuration in the outermost shell. LREEs, ranging from lanthanum to gadolinium, have a single or no spinning electron in the outermost 4f shell while HREEs, ranging from terbium to lutetium, have paired electrons in the 4f shell. This difference in electronic configuration is responsible for the differences in physical and chemical properties of REEs."

Jan 1, 2017

By Jon C. Yingling

Lean manufacturing, pioneered by Toyota, has been credited with the most significant improvements in production efficiency and product quality since the transformation from craft manufacturing to mass production in the early 20th century. It represents a comprehensive philosophy for structuring, operation, control, and management of production systems that is believed to have wide applicability. This paper outlines major lean manufacturing principles and discusses their potential for application in the mining industry.

Jan 1, 1999

By P. M. Hawley

In April 1975 Kaiser Steel Corporation and the United States' Department of Energy entered into a cost-sharing agreement for the demonstration of shield-type longwall supports on three consecutive longwall panels at Kaiser's York Canyon' Mine in New Mexico. Under this agreement the Department of Energy supplied 117 Hemscheidt 320 HSL caliper-type shield supports and hydraulic pumps for the duration of the demonstration. The purpose of the demonstration was to educate the U.S. coal mining industry as to the benefits in production, productivity, health and safety, and increased coal extraction afforded by shield-type longwall mining systems and to provide the industry with a working model. A detailed description of this demonstration is given in U.S. Department of Energy Publication No. DOE/ET/12530-T1, entitled "Demonstration of Shield-Type Longwall Supports at York Canyon Mine of Kaiser Steel Corporation," hereafter referred to as the York Canyon Report.

Jan 1, 1984

By Oscar Cabello, Luis Mendieta, Maribel Guzman

Mineral flotation processes generate large volumes of tailings, which must be disposed of efficiently and safely. In addition to dry stack disposal, the possibility of reusing these tailings as aggregates in shotcrete is an interesting alternative. Tailings samples from a mining operation in southern Peru were characterized by granulometric analysis, X-ray diffraction and Scanning Electron Microscopy. Concrete samples were obtained with different tailings formulations. The samples were subsequently subjected to geomechanical testing. The results showed that replacing 20% to 30% of the tailings with aggregates in shotcrete production achieved compressive strengths exceeding 30 MPa after 28 days of curing, with an energy absorption capacity of 500 joules. Results show that this shotcrete can be used in the support stage of the mining cycle in underground mining.

Feb 22, 2026

By G. Chancellor

"INTRODUCTION The paste plant is located at the Barrick Goldstrike mine in Northern Nevada on the Carlin Trend. The Goldstrike property consists of an open pit and an underground mine; along with two processing facilities: a roaster and an autoclave. The underground portion of the mine produces approximately 1,800,000 ore tons per year and approximately 400,000 ounces. The mine is broken up into four distinct zones: Banshee, Meikle, Rodeo and Northpost. The current paste plant services both the Rodeo and Northpost zones. Development of the conceptual designs and permit approval for this plant was an extensive process that took over a decade to complete. A testing program was developed in conjunction with this process and implemented throughout to ensure the following metrics were achieved: ensure no environmental impact, material available onsite would be able to flow through the pipe to all required locations, and that this material could achieve the appropriate final strength. PLANT AND UNDERGROUND CONSTRUCTION This is the first paste plant to be built in Nevada. The paste plant at Goldstrike began construction in January 2012 and was completed in March of 2013. This plant was constructed to service the Rodeo side of the underground mine which previously utilized a cemented rock fill (CFR) plant to meet their backfill needs. However, in March of 2013, the same month the plant was commissioned, the raise that fed this CRF plant was mined out in a planned phase of the adjacent open pit. This made the switch to paste all the more difficult as it was being relied on for as the sole source of backfill production even though the system yet to be fully tested and optimized. The plant was designed to be fed with onsite Roaster tailing which would be thickened and then mixed with cement and fly ash. The plant was designed to pump 177 tons of paste per hour with a utilization of 65%. The original design specifications for the paste were 77% solids with varying binder contents depending on where the paste was being placed"

Jan 1, 2015

By Thomas A. Simpson

Hydrogeological techniques were used to solve problems of slope stability in open-pit mines of the Eufaula bauxite district, Alabama. Geologic and hydrologic data were evaluated and used to design a system of dewatering wells to enable the operators to mine bauxite more efficiently and economically. Walls of open-pit mines in the district were subsequently stabilized by the operation of the dewatering system. Three open-pit mines, each at varying stages of the mining process, of the A. P. Green Refractories Company, were used to develop a sequential series of guidelines that indicate how to effectively remove ground water from the formations surrounding the ore bodies in the district. The use of sound engineering principles in well design, in combination with the correct interpretation of the pit hydrology provided the basis for solutions of the slope- stabilization problem aided in the economical removal of bauxite from mines of the district.

Jan 1, 1975

By R. Mensah-Biney

The aqueous biphase separation process (ABS) has been used to separate ultrafine industrial minerals. The partition behavior of TiO2, Al2O3, Fe2O3 and kaolin was not pH dependent. The partition behavior of SiO2 was, however, pH dependent. The partition coefficient of kaolin in PEG 3400/ Na2CO3 biphase system was = 150 and that of the silica in the same system was = 0.02, resulting in a separation factor of = 8500 between kaolin and silica. The aqueous biphase separation system was used to separate free silica from kaolin in a raw clay sample from Mexico. The partition behavior of mica, feldspar and clay from North Carolina was also evaluated.

Jan 1, 1999

By Valerie Kollonitsch

Functional mineral pigments are used in large quantities in paint, paper, plastics, rubber, textiles, agriculture, and several other industries. U.S. consumption in 1969 is estimated at over 5 million tons a year, valued at nearly $150 million, as shown in Table 1. Originally extender pigments were employed only to lower cost. They were thought of merely as adulterants to replace more expensive prime pigments and binders. However, over the years their role has become better understood, and today their main functions are: - Increasing strength, stability, and service life. - Improving surface properties. - Enhancing application and processing properties. - Extending prime pigments. - Controlling viscosity and package stability - Lowering overall costs of the finished product. The principal minerals used as functional pigments are kaolin, ground calcium carbonate, talc, and asbestos. Other minerals include barytes, attapulgite, diatomite, mica, ground silica, wollastonite, and nepheline syenite. Several synthetic products, including precipitated calcium carbonate; precipitated, gel, and fumed silica; alumina trihydrate; and barium sulfate, compete with mineral products. They are more expensive, but often have more closely controlled particle size or other properties because they can be tailor-made according to the requirements. This paper covers only natural products selling for $10 or more a ton, approximately the lower limit for pigment grades. Data refer only to consumption in pigment applications. For example, such applications as filter aids for diatomite are not included. Key properties of the major mineral pigments are given in Table 2. It is important to note that these properties are primarily physical rather than chemical. In general, these products are sold to performance specifications for what they can do rather than on chemical composition specifications on what they contain.

Jan 1, 1969

By Mahesh C. Jha

Cyanidation has established itself as the main process for extracting gold from ores in this century. However, many ores exhibit refractoriness to the conventional cyanidation process. The main cause of the refractoriness is generally the presence of carbon, tellurium, and sulfides, particularly those of antimony, arsenic, and iron. The problem is usually solved by either modifying the cyanidation conditions or providing an oxidation pretreatment. This paper presents results from studies that help in understanding the causes of refractoriness of various gold ores. This is followed by a discussion of many processes that have been developed to solve the problem such as intensive cyanidation, pressure cyanidation, carbon-in-leach cyanidation, and pretreatment processes such as roasting, chemical oxidation, autoclave oxidation, and bacterial oxidation.

Jan 1, 1986

By Richard V. Good, John B. Harvey, Lloyd S. Jones

INTRODUCTION The term "Rapid Underground Excavation" is generally associated with high speed tunnel advance with large volumes of excavation, and indeed this is the type of work for which most of the recent innovations in methods and new machinery have been developed. However, the term applies as well to any underground excavation process that results in an earlier project completion than would be expected with conventional methods, and hopefully with a decrease in total unit excavation cost. Often significant progress has been made during the primary stages of an underground construction project and then an inordinate amount of time and effort has been expended on small units of "miscellaneous" excavation which has delayed the overall project completion and escallated overall unit costs. Construction at the Nevada Test Site of the Atomic Energy Commission for underground testing frequently requires significant amounts of so called "miscellaneous mining" such as short access drifts, cross cuts, alcoves, niches and concrete keyways. Many of the keyways must be excavated without disturbing the rock beyond the excavation lines and construction scheduling often dictates that much of the work must be accomplished without disturbing sensitive electronic equipment already installed. In order to cut down on lengthy and costly delays required for the tedious manual excavation of much of this miscellaneous mining, a market search was made for suitable mechanical excavation equip-

Jan 1, 1997