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By Giovanni Osellame, Jean Habimana

"The Montreal Metro Blue Line Extension Project is part of a metropolitan Program that was launched in 2009 by the Transportation Ministry of Quebec to add additional extensions to existing metro lines in the cities of Montreal, Longueil and Laval with the intention to meet current demand and future growth within the Montreal agglomeration. Specifically the Blue Line Extension Project will add five underground stations to the East of the Montreal. The paper addresses the preparation and the implementation of a three-step geotechnical and geo-environmental investigation program and preliminary design considerations such as the selection of a preferred horizontal and vertical alignment, the selection of construction methods based on previous local experience and current industry trends, as well as preliminary sizing of underground infrastructures. PROJECT BACKGROUND An agreement between the three mayors of the Montreal Metropolitan City agglomeration, namely, Montreal, Longueil and Laval prompted the Government of the Province of Quebec to create a project office to oversee the studies of extending the existing metro network. The last extension of the existing metro network was completed in 2008 with the Laval extension, which consisted of adding three stations from the existing Orange line. The current extension Program consists of three different extensions, namely extending the Orange Line to Laval and finishing the loop, extending the Blue Line to the East of Montreal by adding five stations, and adding five stations on the Southshore of the St-Lawrence River for the Yellow Line extension. The extension program also requires the construction of an underground storage and maintenance garage located to the north-west of the existing Cote-Vertu station on the Orange line. Figure 1 shows the overall extension program with the existing network."

Jan 1, 2016

By Richard R. Klimpel

Part 2 of this article continues the discussion of a 10-year, multimillion dollar research and plant testing program on slurry rheology and grinding circuits. The first part of the article (ME, Dec. 1982) presented the basic concepts identified by the research and some laboratory test results. This section Illustrates typical Industrial scale test results and Identifies some industrial operating implications of controlling rheology by different methods. At least four controllable factors decide the rheological character of a slurry-slurry density or percent solids, particle size distribution, chemical environment, and slurry temperature. The second factor has two interrelated facets: the shape of the particle size distribution which controls packing behavior of the solids, and the fineness of the distribution. Finer particles increase interparticle forces and viscosity. As indicated in Part 1, during a given grinding test it is possible for all four factors to change. However, regardless of the particular settings of the four factors in a given test, if the resulting rheological character is either dilatant, pseudoplastic, or pseudoplastic with yield, the associated breakage rate is correlated with the current rheological character. It is obvious, for example, in batch grinding tests run at constant percent solids, that the second and third factors, where appropriate, are changing during grinding because size distributions are changing and the production of fresh surface area takes up unadsorbed chemical. Thus the corresponding rheological character change in batch tests with increasing grind time would be dilatant to pseudoplastic to pseudoplastic with yield. The degree to which this transformation occurs depends on the changing setting of the four factors over grinding time. In continuous grinding tests, one might logically expect that dramatic changes in any one of the four factors will be less likely to occur. It will be shown that continuous mill operations offer some unique opportunities to take advantage of possible rheological transformation by more direct operational control of the settings for the four factors. One extra observation noted in the rheological studies was the variability in the location and extent of region B (pseudoplastic behavior) for the various coals and ores tested. The location of region B was usually in the region of 45-55% solids by volume and was of the extent of 0-8%, or 2-11% with chemical addition. The corresponding increase in net production ranged from 0-10% in region B and 0-21% in region B&apos;. When region B is small or zero (no pseudoplastic character is exhibited) no increase in production will be observed and the use of chemicals is often marginal. There are several reasons for some materials exhibiting this quick transformation from dilatancy to high yield values often at surprisingly low percent solids by volume such as 30%. One condition identified was for materials containing high levels of viscosity-producing elements such as- carbonates or clays. A second condition documented was for materials that exhibited unusually fine primary fragment distributions (fine B1,; curves). This corresponds to materials having small y values of < 0.5. Such a slurry developed a yield value quickly during grinding because of the rapid buildup of fines. A related problem can be presented by materials exhibiting excessively coarse primary fragment distributions, y values > 0.9. Breakage of this type of material produces size distributions that give poor packing efficiencies even at long grind times, thus hindering the normal rheological transformation presented earlier. A final condition that can cause the occurrance of region B to be small or zero is when the media void volume filling of slurry is < 100%. Figures 5a and 5b use previously published data of this study to demonstrate the influence of solids loading and weight percent solids on the net production of taconite ore in a laboratory batch ball mill. In particular, Fig. 5a illustrates several trends not generally recognized until this study. They include these two: • Increased slurry density allows for increased solids loading before passing through the maximum in the net production curve where the fall-off is due to non first order breakage. • The use of rheology control chemicals such as GA-4272 allows this trend to be extended to higher slurry loadings with an increase in net production over any previous condition by keeping grinding first order. Figure 5b shows the same data as Fig. 5a plotted for constant weight loadings. These various figures of net production versus percent solids show the location and extent of the regions A, B, and C presented in Part 1 as a function of solids loading. It is obvious that the rheological transformation pattern described earlier does not hold true for slurry loadings corresponding to less than the void volume of the media, which is also a region of

Jan 1, 1983

By Bernd Hagenah, Hans-Peter Vetsch, Eric Jones, Sean Cassady, Danielle Johnson, Petr Pospisil

There are a number of issues associated with freight trains in non-electrified tunnels that are fundamental during the planning and operation of a rail tunnel. During uphill operation, increased air temperatures at the air intake locations of diesel trains can reduce diesel motor efficiency (stalling/choking) and affect HVAC systems. Strong airflows can aggravate fire scenarios due to fanning or water-reactive cargo materials. This paper focuses on the impact of freight trains on tunnel safety concepts, strategies to overcome heat issues at locomotive air inlets and air quality in tunnels operating diesel trains.

Dec 1, 2022

By Tadashi Nishida

Subsidence due to mining caused various kinds of damage to the surface structures, and actually great deal of mining damage becomes the severe social problem at some time in many coal fields, but the most of mining damage was restored at present. Recently, the effect of old coal working on the deformation of newly constructed structures has become into question, because it was obliged to plan many engineering structures in old mining areas for the shortage of adequate construction sites and the difficulty of getting location. That is, building, dams, bridges for railroads and highway, power plants, tunnels, storage tanks and so, have to be built on the ground which has old coal working.

Jan 1, 1982

By L. W. Teal

The Paupers Dream Property is located in the northern Boulder Mountains, southwestern Montana, 30 km southwest of Helena. The property is situated in the central portion of the Butte-Helena gold belt, a NE trending lineament marking a zone of recurrent, late-Cretaceous to mid-Tertiary volcanic activity. Geology consists of a plutonic basement of late-Cretaceous quartz monzonite overlain by a pre-volcanic basal conglomerate and a complex sequence of Oligocene rhyolitic volcanics. Gold mineralization occurs in fracture-controlled quartz veins, silicified stockwork, and brecciated shear zones as auriferous pyrite, arsenopyrite, and disseminated free gold. An estimated 60,000 tonnes averaging 2.5 g/t was produced from the Porphyry Dike, Venus, and Paupers Dream Mines on the property. Current drill indicated reserves (May, 19861 are placed at 6,946,000 tonnes averaging 1.45 g/t gold.

Jan 1, 1987

By R. F. Harig

Designing an underground nuclear waste repository is a complex process. Although many decisions are involved before the design is complete, the first three--what the target horizon is, what the underground boundary is, and where the entry point will be located--are important because they establish the basis for the entire repository design. Even more important than these decisions, however, is the data on which the decisions are based. Because the current data are limited, an aggressive data gathering program is needed during the next design phase to augment information about the intricate interplay among all facets of the repository design and the geologic medium in which the proposed repository is to be developed. Although unique to modern engineering enterprises, the challenges involved in designing a repository in the unsaturated zone are within current technology and engineering practices.

Jan 1, 1991

By V. W. Smith

For the past 50 years, the primary crushing of stone at the Dolase Bros. Co. Richards Spur Quarry. 13 miles north of Lawton, Oklahoma, has been accomplished by a Traylor 42-inch gyratory crusher. The production capacity of the primary system, consisting of a feeder, grizzly, and the gyratory crusher, was approximately 2100 tons per hour. Shot-down scone was hauled from the working face about one mile to the feeder by a fleet of Caterpillar Model 773&apos;s and WABCO 60- and 65-ton trucks. In order to maintain production, nine to ten trucks and four Caterpillar Model 992 front-end loaders were required to be operational at all times.

Jan 1, 1986

By Douglas N. Kendall

There are three definite steps in the making of a mining industry in any country. These are as follows: Step A - Geological Mapping This step covers the basic geological mapping of the country at scales of 1/250, 000 up to l/50, 000. This step eliminates territory and directs the exploration teams to the areas of potential interest. Step B Prospecting This step includes all phases from detailed geology through geophysics and drilling up to the point of proving that an economic ore body exists. Step C - Mine Development This is the expensive step, involving the creation of the mine, including shaft-sinking, ore treatment plant, etc.

Jan 1, 1963

By Kevin Andrews, SETAREH GHAYCHI AFROUZ

Ground control analysis and groundwater inflow assessments for underground coal mines require in-depth field investigations including, but not limited to, geological and geotechnical core logging, downhole geophysical logging, laboratory rock strength testing, and packer (Lugeon) testing. Field and laboratory data collection are time consuming and expensive, and an initial understanding of the expected trends among various geotechnical and hydrogeological parameters can assist with the planning and optimization of geotechnical characterization studies and grouting plans. In this study, a comprehensive database is analyzed, comprised of important rock mass characteristics (hydraulic conductivity, rock quality designation (RQD), and lithology) for coal-bearing rocks in the Central Appalachian Basin. Statistical analysis of the data is completed to establish an enhanced understanding of geotechnical and hydrogeological conditions expected to be encountered as underground coal mining passes near and beneath streams and rivers. The results of the study provide valuable reference material for the coal mining industry for completion of shaft installations, mine stream crossings, environmental assessments, and grouting and mine dewatering designs.

Jul 1, 2023

By S. C. Libby

The amount of fine material (minus 60 Tyler mesh) generated during calcination and/or handling of calcined abrasive grade bauxite from Alcoa&apos;s operations at Moengo, Suriname, has recently increased relative to past production experience. Bulk samples of raw abrasive grade bauxite from three deposits in the Moengo area have been studied in order to determine the factors controlling the generation of fine material samples from the Jones IC and Tapira deposits, which generate excessive amounts of fine material, have been compared with reference samples from the Begi Gado deposit, which does not generate excessive fine material. Additional type samples of abrasive grade and marginal abrasive grade bauxite from deposits in the Moengo area which represent different bauxite textures found in the Jones IC, Jones I, and Begi Gado deposits have also been studied. Field observations in the Moengo area have indicated that abrasive grade bauxites with a dull, earthy appearance generally do not generate excessive fines. On the other hand, excessive fines are generally associated with coarsely crystalline bauxite in which the gibbsite crystals appear to sparkle in sunlight.

Jan 1, 1980

By R. W. Macqueen

Organic matter commonly associated with Mississippi Valley-type (MVT) lead-zinc deposits may be used to assess the burial/thermal history of host rocks and sulfides. Organic matter may also have been involved in the genesis of H2S required to precipitate sulfide ores. Pine Point, Northwest Territories, Canada, provides an example. Located on the south shore of Great Slave Lake, Pine Point is an operating world class deposit which has produced 58 million tons of ore containing 3.0 percent Pb and 6.1 percent Zn from more than 40 Individual orebodies. Well-documented paleokarst features in a Middle Devonian carbonate complex are the main ore hosts. Sphalerite and galena ores are mainly open space fillings, and, from fluid inclusion studies, were deposited from saline fluids at temperatures of up to at least 100°C. Forms of organic matter occurring in the Pine Point barrier-reef complex Include indigenous organic matter, heavy oil and bitumen. Based on numerous geochemical criteria, it is clear that heavy oils and bitumens were derived locally from indigenous organic matter. The geochemical character of the Indigenous organic matter demonstrates that the barrier-reef complex is immature to marginally mature with respect to petroleum generation, and has not been heated above about 60°C maximum. Thus sphalerite with fluid inclusions that yield temperatures up to about 100°C represents former thermal anomalies. Bitumen is of two main forms at Pine Point: widespread soft, tarry material soluble in organic solvents (unaltered bitumen); and hard, brittle, glassy material that is mostly solvent-insoluble, and associated with white sparry dolomite and lead-zinc ores (altered bitumen). There are also partly altered bitumens. Unaltered bitumens have atomic H/C ratios of about 1.4, sulfur contents averaging 7.8 percent, and sulfur isotope ratios 634S) of approximately +4.6 per mil. Altered bitumens have atomic H/C ratios averaging 1.02, sulfur contents averaging 22 percent, and 634S values of about +12.9 per mil. These data and the organic geochemical character of a large suite of bitumen samples analyzed, strongly support the concept that some bitumen has been involved in the thermochemical reduction of sulfate to produce the H2S required to precipitate the ores. Mass-balance calculations indicate that the amount and degree of alteration of bitumen is more than enough to account for the reduced sulfur species deposited as metallic sulfides at Pine Point. MVT deposits, including Pine Point, seem to require the coincidence of available metallic Ions, pre-existing pore space, and a precipitating agent. A close look at organic matter in more MVT settings may outline trends in distribution or alteration which can be used as indicators of past thermal environments and processes of ore deposition.

Jan 1, 2013

By J. K. Ross, K. O. Hoal, S. K. Appleby

Understanding ore variability is a key factor in the geometallurgical analysis of a deposit and is beneficial to process development and mine planning. Ore variability is a function of the mineralogy of a deposit, in terms of both ore and gangue minerals and their textural relationships. This study integrates optical microscopy and quantitative mineral analysis to characterize the mineralogy and texture from 13 samples from different lithologic units at the Bingham Canyon Mine. The analysis identified several parameters, such as modal mineralogy, alteration assemblages, distribution of mineral phases and alteration assemblages and microfracture and void space distribution. These parameters can have an impact on the materials’ behavior during processing. This study demonstrates that quantitative mineralogical analysis can provide detailed information for improved understanding of ore variability.

Jan 1, 2010

By Hongjie Yu, Mike Mooney

Transitions between geological/geotechnical soil units have a critical impact on the operation and performance of a tunnel boring machine (TBM). Geostatistics-based probabilistic modeling is used to quantify the uncertainty in soil transition locations. This paper presents two unique soft-ground tunneling case studies where the results from the geostatistics-based probabilistic modeling are compared to the TBM data and as-encountered ground conditions derived from the actual TBM data. The assessment enhances the confidence in using geostatistics to improve ground awareness for efficient tunnel construction, minimizing different site condition (DSC) claims, and improving decision-making on tunnel projects.

Dec 1, 2022

By J. L. Young

The McLaughlin Mill started operating in January, 1985. For the first eighteen (18) months start-up, initial operation, and circuit debottlenecking have been done. The mill was designed to recover gold from a refractory ore requiring acid autoclaving pretreatment. This paper discusses the problem associated with bringing this complex hydro-metallurgical plant to consistently achieve design tonnages. Also, briefly described are the mill flowsheet, training program, permitting, and process and project development.

Jan 1, 1987

Strainburst phenomena, generally characterized by a sudden release of energy in a volume of highly stressed rock, are often encountered in such situations like crown pillar bursts in cut-and-fill mining, face bursts at development headings and floor bursts in deep shaft sinking. This paper describes a simple FE modeling approach which leads to the calculation of the energy release rate (ERR) and the total energy storage rate (TESR) in the rock mass around the openings. The merits of using such energy parameters in the analysis of strainburst problems to identify areas of high energy release/storage are discussed. However, much site-specific back analyses are needed to better understand how strainbursts and energy parameters are inter-related.

Jan 1, 1998

By Robert A. Robinson, Steven R. Thompson, Harvey W. Parker

The Mt. Baker Ridge Tunnel, under construction in Seattle, will be the world&apos;s largest-diameter soil tunnel with an inside diameter of 19.2 m (63 ft) and an effective outside diameter of about 24.4 m (80 ft). The five-lane highway tunnel will be constructed using a "stacked-drift" scheme in which an articulated or "flexible" tunnel lining consisting of 24 concrete-filled drifts is constructed to form a horizontal compression ring followed by removal of the soil core. Geotechnical factors, including variable strength hard fissured soils, high horizontal stresses, potentially unstable sands, and prior slope instabilities, significantly influenced the innovative design and construction approach.

Jan 1, 1983

By Fathi Habashi

LEACHING IS the process of extracting a soluble constituent from a solid by means of a solvent. In extractive metallurgy it is the process of dissolving a certain mineral (or minerals) from an ore or a concentrate, or dissolving certain constituents from metallurgical products such as calcines, mattes, scrap alloys, anodic slimes, etc. In this respect, either one of two purposes can be achieved: 1) Opening of ores, concentrates, or metallurgical products to recover the metal values. 2) Leaching easily soluble constituents (usually gangue minerals) in an ore or a concentrate in order to have it in a more concentrated form, e.g., the

Jan 1, 1970

By T. L. Conley, J. J. Rozek

The $2 billion (A$) Melbourne City Link Project is one of the largest and most important metropolitan road developments ever undertaken in Australia. The project involves two three-lane vehicular tunnels totaling 5 km, constructed as deep as 65 m underground. The 3.4 km Burnley tunnel is one of the world&apos;s longest three-lane tunnels. The project is being delivered under a DBOOT [design-build-own-operate-transfer] process and all design and construction is performed to ISO 9000 standards. Tunnel excavation began in May 1996, and the tunnel will open to traffic in 1999. This paper focuses on the range of construction techniques utilized during construction.

Jan 1, 1999

By I. Iwasaki, H. Dho

The role of sodium silicate in the anionic flotation of a Florida phosphate ore was investigated using laboratory continuous flotation tests, frothabiliry tests and SEM observations. In the absence of sodium silicate, Ca I+ promoted the unwanted activation of quartz by forming calcium bearing precipitates. The addition of sodium silicate enhanced the flotation efficiency through: 1) the removal of impurity minerals and calcium-bearing precipitates from quartz surfaces by dispersion, 2) drier and more persistent froths stabilized by oily droplets containing calcium silicate precipitates, and 3) higher specific flotation rates of phosphate relative to quartz, leading to faster flotation rates and increased selectivity of separation.

Jan 1, 1991

The primary goal of a maintenance information system should be to aid the maintenance department in providing the required equipment or plant availability at the lowest possible cost. To achieve this goal, the system must provide information in support of the following objectives: (1) establishing the best fleet, equipment, and component configuration; (2) establishing the best maintenance program; (3) executing the defined maintenance program efficiently; and (4) monitoring equipment availability. These objectives can be satisfied with five groups of reports. Each of these groups should provide regular, periodic reports to aid in planning and monitoring trends, exception reports to identify problems, and on-request reports to provide analytical capabilities.

Jan 1, 1979