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By William W. Edgerton, Moussa Wone, David H. Corkum, Carlton M. Ray

"The DC Clean Rivers (DCCR) Project is a 25 year, $2.6 Billion court ordered project to reduce combined sewer overflows (CSOs) discharging into the Potomac and Anacostia Rivers and Rock Creek, and also reduce flooding in the northern areas of the District of Columbia. Like all massive infrastructure programs, DCCR faced technical challenges, management challenges, risks of cost and schedule overruns, procurement challenges, and financing challenges. While DC Water is no stranger to large capital improvement projects (CIP), this CSO Program represents a once in a lifetime event for the Owner requiring the assembly of a single purpose team to implement. Some of the DCCR Project team’s most successful accomplishments to date are attributable to its introduction of early contractor involvement (ECI) to thoroughly vet the work from the perspective of the future constructors, development of functional baselines to share risks that are difficult to price and reduce reliance on geotechnical baseline interpretation during tunnel excavation, and attainment of financing through Municipal Century Green Bonds based on using design criteria of a minimum of 100 year life for the structures to establish intergenerational equity and fairness. This paper will discuss these innovations in detail and provide some sets of recommendations for the underground industry on when and how to use different approaches to better manage projects of this magnitude. INTRODUCTION The District of Columbia Water and Sewer Authority (DC Water) is an independent multi-jurisdictional authority that was established in 1996. Its primary mission is to provide water distribution services to more than 640,000 residents in the District of Columbia (District), and sewer treatment and disposal to 1.6 million residents of the District, Montgomery and Prince George’s counties in Maryland and Fairfax and Loudoun counties in Virginia."

Jan 1, 2016

By J. J. Fritts, J. L. Patrick, T. L. Wright, C. O. Ensign, W. S. White, J. W. Trammell, J. C. Wright, D. J. Hathaway, R. J. Leone

The copper deposit at White Pine, Michigan, from which a little more than 5 per cent of United States primary copper currently is produced, is a large stratiform orebody, 4 to 25 feet thick and several miles across. The present ore column, containing about 1.2 per cent copper as chalcocite and native copper, is confined to the basal beds of the Nonesuch Shale. This upper Keweenawan (Upper Precambrian) formation is a distinctive gray siltstone unit, about 600 feet thick, overlying and overlain by thick red-bed sequences. All these rocks contain abundant volcanic debris, but the latest known igneous activity within 50 miles antedated the Nonesuch Shale. The rocks are unmetamorphosed and only moderately deformed, mainly by tilting and faults. Pyrite, presumably syngenetic, is the only prominent sulfide throughout most of the Nonesuch Shale. The basal beds of the formation, however, contain disseminated copper minerals instead of pyrite and constitute the cupriferous zone. On a regional scale, the top of the cupriferous zone cuts across bedding, and ranges from an inch or so above the base of the formation in some areas to more than 50 feet in others. However, within the cupriferous zone the distribution of copper shows remarkable stratigraphic control. Certain beds are copper-rich compared to the beds that lie between them and the differences persist throughout the White Pine region. Several darkgray thinly laminated beds in the lower 10 to 25 feet of the Nonesuch Shale are rich enough and sufficiently close enough together to constitute a mineable thickness where they lie within the cupriferous zone. Pyrite is the characteristic sulfide of the Nonesuch Shale as a whole. The principal sulfide mineral of the cupriferous zone at the base of the formation is chalcocite. The succession of minerals outward and upward from the center of the cupriferous zone is native copper-chalcocite-bornite-chalcopyrite- pyrite. The bornite and chalcopyrite are confined to a narrow fringe at the margin of the cupriferous zone. This pattern of mineral zones is believed to represent reaction between syngenetic pyrite and introduced copper. The main copper mineralization is independent of structure and apparently antedates deformation. Details of the geometry of the cupriferous zone indicate the possibility that copper was introduced from the underlying sandstone prior to lithification. The source of the mineralizing solutions and their copper is not known.

Jan 1, 1968

By Shu Fan Chau, Innes Duncan, Harry Asche, Bill Newns

The North Auckland Line (NAL) in Northland, New Zealand, is being upgraded to pass Hi-Cube containers. The line includes many tunnels and bridges which need to be refurbished to improve structural clearances and line capacity. Tunnel 2 along the line, the Makarau Tunnel, has posed special challenges. Opened in 1898, the tunnel suffered multiple collapses during construction and has shown significant distortion during operation. The tunnel has been repaired many times since opening. Successfully enlarging this delicate and distressed structure has involved historical research, advanced analysis and design, and careful construction. The results provide lessons for dealing with brick lined tunnels and poor ground conditions

Jun 13, 2021

By P Fullagar

Automated multi-sensor core loggers (MSCL) measure petrophysical properties of diamond drill cores, including gamma density, P-wave velocity, electrical conductivity and magnetic susceptibility. A Geotek MSCL system has been used to record petrophysical data on archival drill core from Cadia East Au-Cu porphyry deposit, New South Wales, Australia, for correlation with metallurgical parameters. P-wave modulus, calculated from density and P-wave velocity, exhibits a correlation with small-scale crushability (A*b) test results, and hence offers a means for æcontinuousÆ characterisation of ore crushability at Cadia East. Magnetic susceptibility has proved to be a good indicator of alteration styles, and is a possible indicator of crushability.

Jan 1, 2009

This paper is intended partly as a summary of the conclusions that have been arrived at by various authorities on this matter, and also with a view to initiate some discussion on the subject, especially as most of the quartz gold mines in Victoria are operated without having any proper assay plans or any idea of the real values other than those given by the mining managers, who, from experience in the particular cases, are supposed to be able to arrive at a correct idea of the true values of- the ore, and, in many cases, oppose any other methods than their own, holding the view that no sampling is equal in correctness to the bulk sample of the battery. The necessity of properly sampling and estimating the ore in a mine in every case, perhaps hardly needs to be urged on the members of the Institute, but is not, apparently, so obvious to others.It is proposed to confine this paper to the sampling of ore reserves in a mine, and the various points which have to be taken into consideration in arriving at values, from the assayer's point of view, leaving the methods of sampling metallurgical products out of consideration for the present. "It is advisable to define" ore reserves" as ore exposed on three sides at least, and accessible to the sampler on all three. "Prospective ore" would include all ore not so fully exposed; but which may, from the nature of the case, and the geological conditions prevailing, be reasonably supposed to exist.

Jan 1, 1904

By P Bergin, J M. Galvin, J Harris, J Li, P Kirsch, M Shi, B Hebblewhite, B Whittaker, R Mitra, D Sprott

Controlling unwanted ground movement is critical in mining as well as many other highly hazardous environments, such as construction and tunnelling. Sharing knowledge about effective hazard management is paramount to improving health and safety and operational outcomes across industries, and some industry sectors have embraced this openness as part of the way that they do business. In 2010, the Australian Coal Association Research Program funded the RISKGATE project to build a body of knowledge for managing a broad range of hazards across mine sites, lease areas and mine infrastructure within a mine-life or product life cycle perspective (eg from exploration through to decommissioning, or design through to operation). The RISKGATE body of knowledge was assembled from Australian coal industry experts through a semi-structured bowtie analysis-based action research workshop cycle. By capturing operational knowledge from industry experts, RISKGATE serves to provide a cumulative corporate memory at a time of high personnel turnover in the coal industry.This paper presents an overview of RISKGATE topics within the geological and geotechnical domain (strata underground, ground control open cut, outburst, coal bumps and bursts, tailings dams and inrush) with a summary of individual topic structures, as well as showing the contrasts and inter-relationships between these ground management topics. The online user can access information about the causes, controls and consequences related to a priority unwanted event (ie the point at which control of energy is lost) and use this information as a prompt for the development of risk assessments, incident investigation, audits of practice/plans/procedures and for training and development.The paper concludes with a discussion of how RISKGATE can be adapted to other mining domains (eg coal outside of Australia, hard rock mining worldwide, construction, tunnelling) and the opportunity for application of this body of knowledge and the RISKGATE action research process for knowledge management in other highly hazardous environments.CITATION:Kirsch, P, Hebblewhite, B, Sprott, D, Harris, J, Li, J, Shi, M, Whittaker, B, Galvin, J M, Bergin, P, Mitra R and Williams, D, 2014. RISKGATE – shared coal mining knowledge for managing risks across ground management, in Proceedings AusRock 2014: Third Australasian Ground Control in Mining Conference , pp 247–254 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Nov 5, 2014

By Gavin J. Faulkner

This paper presents an investigation of some alternatives, and improvements to timber posts and cribs. The purpose is to find a cheaper, better, easy to install, and effective means to replace or improve them. Selection of supports needs to take account of several factors. These factors include the mechanical behavior of the support, technical feasibility, and cost. In this paper a variety of supports are compared on these bases. Particular advantages and disadvantages of those supports have been determined through published material and a testing program. A broad evaluation of a number of specific groups of supports is presented. Included in this evaluation are timber posts and cribs, steel friction props and several, newer developments such as the Micon Yield Capsule and the Super Post. Another support that will be briefly discussed is steel-fiber-reinforced concrete. Particular emphasis will be placed on the Micon Yield Capsule and the Super Posts on which preliminary testing has been carried out. The testing results are presented in detail. The shortcomings of the test procedure are pointed out and some new ideas to improve the testing in the future are proposed.

Jan 1, 1986

By J. Loeb, R. Ramanathan, P. Cameron

All mining operations, including iron ore, maintain a focus of continuous improvement and asset optimisation in their operations. As all the operations in the Mine-to-Mill value chain are inter-dependent, available technologies that address efficiencies across the value chain are once again in the spotlight as companies are driven to improve productivity and maximise mine site profits to increase return on capital invested. Core to continuous improvement is the need to understand the baseline and the impact of changes to the process. In this paper, we discuss some of the key attributes in the mine to mill process, including their influence on productivity and cost, the need for direct measurement and areas where they should be applied. Many initiatives can be considered to improve mine to mill processes. Mining operations are planned and executed based on designs and models to achieve the operation’s objectives. However, there are many variables in the different parts of the value chain, such as blasting, material handling, crushing and screening. Measurement of the key attributes establishes the baseline for Mine to Mill (or Pit to Plant) performance which is necessary to understand the impact of any proposed improvements to the process design and execution and to monitor the outcomes on an ongoing basis to sustain the improvements that have been implemented. We have focused this paper on two types of measurement – blast movement and particle size of materials through the mine to mill process. Several innovative technologies are already available to measure these attributes and assist operations improve productivity and mine site profits.

Mar 2, 2022

By D. W. Bridges, Donald R. Peterson, Masami Hayashi

Techniques are described for recovering about 80 pct of the cobalt and nickel contained in superalloy scrap by anodic dissolution of the scrap and simultaneous electrodeposition of a pure cobalt - nickel alloy at the cathodes in an electrolytic cell partitioned by permeable diaphragms into separate anode and cathode compartments . Superalloy scrap was alternatively prepared for subsequent anodic dissolution either by melting and casting massive scrap into suitably sized anodes , by packing moderate - sized discard scrap in inert metal baskets that subsequently served as anodes , or after concentrating the superalloy portion of grinding debris , by magnetic separation to reject corundum or other abrasives , slagging any remaining abrasives from molten grindings , and finally casting the superalloy metal into anodes . In the processing , purified electrolyte -- 1 N in NiSO4 and in NiCl₂ , and 0.1 N in CoSO4 and in CoCl2 --was charged to the cathode compartments and discharged from the anode compartments at a rate sufficient to overcome the backward migration of ionic impurities from the anodes to the cathodes . Discharged electrolyte was purified by reacting it first with SO2 and next with limestone , and then recirculated to the cathode compartments , in which a 50 pct cobalt - 50 pct nickel alloy was deposited on either blanks of stainless steel or starting sheets of cobalt - nickel alloy . The process was made self - sustaining by either adding H2SO4 to the catholyte feed to throttle the rate of cobalt - nickel deposition , thereby compensating for the slower rate of cobalt - nickel dissolution from the anode and losses occurring in electrolyte purification , or alternatively , adding H₂SO4 to

Jan 1, 1964

By K. Oraee

The empirical rock failure criteria play an important role in predicting the mechanical behavior of rocks, since affecting parameters on the behavioral properties of rocks are complex and numerous. Usually the empirical failure criteria are obtained by statistical methods, namely by means of fitting the mathematical function onto the experimental data. For evaluation and verification of the results, however, the quality and accuracy of the fit must be considered. This paper studies the efficiency and accuracy of conventional empirical rock failure criteria using a new approach, which is based on the analysis of uncertainty amplitude on the constant parameters of each criterion. The approach adopted here, is based on the combination of some parameters such as Mean Squared Error (MSE), Root Mean Squared Error (RMSE), type of function, degree of freedom and the confidence level of constants. Correlation coefficient (R2) is then a comprehensive test and can be used effectively for comparison and accuracy of empirical rock failure criteria.

Jan 1, 2012

The Heavy Media Separation plant operated at Lidsdale siding, eight miles from Lithgow, by the N.S.W. Mining Co. is a product of the Western Machinery Company, of D.S.A.This mill, designed to use finely ground magnetite as the heavy medium, was prefabricated in America and shipped to Australia for erection.First operated early in December, 1951 it has worked on a two-shift basis since. Designed for an input rate of 330 tons per hour, this mill is capable of washing 4 in. x /u in. coal down to its inherent ash by removing all heavy material, including high-ash coal.The principle is quite simple. A stream of raw coal is fed into the separatory vessel which contains a liquid medium, the density of which is adjusted to produce the desired split between coal and refuse. In this bath the lightest coal floats, and all material heavier than the specific gravity of the medium sinks, and is removed separately. Such a system is,. ideally suited to Western coal, as there is no definite splitting point between coal and refuse. Inherent ash of the coal fed to the plant ranges from 8 to 25%, the corresponding density range being from 1.28 up to 1.8.Generally speaking, the higher the density the higher the ash content of the coal.The density in the separatory vessel (hereafter called the cone) can be quickly and easily adjusted throughout the above range to any desired value. Customer requirements, coupled with the economics of washing, dictate the proper specific gravity to be maintained. At present this is held at 1.52...

Jan 1, 1954

By George J. Tamara

The urban environment presents special challenges for the design and construction of earth retention systems. Complications arising from difficult subsurface conditions are compounded by the presence of urban infrastructure and existing and prior construction. The proximity of adjacent structures as well as intense prior use can cause special concerns including the potential for archeological artifacts or contaminated ground or ground water. Utilities and structures may be particularly vulnerable to the effects of ground movement, dewatering and vibrations. Difficulty of access, congestion and limited work areas may severely restrict means and methods of construction. Dewatering may be limited or prohibited because of concerns for disposal of clean or contaminated water, depletion of aquifers, drawing of contaminants to the site or dewatering induced settlements.

Jan 1, 2003

ONE of the phases of mining wide ore-bodies, such as are found in Broken Hill, is the laying-out and design of the sill floor gangway timber, When, in the above operation, a detail has to be repeated frequently, it is desirable in the interests of efficiency that that detail should be standardized as far as possible. Before arriving at a standard design e.g., a crosscut layout-it would seem necessary to compare its strength with some other unit of timber and see that the general design is at least as strong as the unit that has been taken for comparative purposes, In these notes no attempt is made to calculate the stresses to which timber underground is subjected, but merely to draw a comparison between the relative strengths of the various cross sections of timber in common use underground.It has been assumed for the purposes of comparison that the milling exerts pressure in a vertical plane only, and is uniformly distributed over any area. A beam supported at both ends, and with a uniformly distributed load, has the maximum bending moment at a point midway between the points of support, and equals- WL2 8 where W = load per unit length. L = distance between points of support.The bending moment also equals M-, where y M = modulus of rupture of the material in question. I = moment of inertia of the section of the beam about a given axis.Y = distance of extreme fibre from that axis. WL2. I The formula -8- = MY- only holds good until the elastic limit...

Jan 1, 1923

By M. A. Reyes, L. Yan

Heat and humidity buildup withn refuge alternatives (RAs) may expose occupants to physiological hazards such as heat stress. The Mine Safety and Health Administration (MSHA) regulations require RAs in underground coal mines to provide a lifesustaining environment for miners trapped underground when escape is impossible. RAs are required to sustain life for 96 h while maintaining an apparent temperature (AT) below 95 °F (35 °C). The National Institute for Occupational Safety and Health (NIOSH) tested a 10-person tent-type RA, a 23-person tent-type RA, and a 6-person metal-type RA in its underground coal mine facilities to investigate the thermal environment over a 96-h period. The test results showed that mine air and mine strata temperatures surrounding an RA occupied by simulated miners (SMs) increased over the 96-h test period. The test results suggest that RA manufacturers should consider this increase in temperatures when calculating and evaluating RA components during surface and laboratory tests. The findings can equip stakeholders with additional considerations for calculating the interior heat and humidity temperature profiles for occupied RAs not tested in situ.

By J. R. Bartels

The U.S. Bureau of Mines has established a wire rope research laboratory to examine the factors that affect the life of wire rope. Two sin-diameter 6x25 fiber core (FC) ropes were degraded on a bending fatigue machine, These were the second and third ropes in a series of tests on this construction and size rope. Tensile and nondestructive tests were performed on samples of the rope to determine the relationship between rope deterioration and rope breaking strength. The tests indicated that once a wire rope nears the end of its service life, both deterioration and the consequent loss of rope strength begin to increase at an accelerated rate.

Jan 1, 2010

By Cesar Sáenz Acosta

El presente texto señala las mediciones de impactos que se han realizado a los programas de responsabilidad social de una empresa minera. Esta medición se realizó a través del cálculo del indicador “Retorno social de la inversión”, aplicando el modelo SROIM o Gestión del Retorno Social de la Inversión. Los proyectos de RS medidos permiten actuar a las empresas de manera responsable con su comunidad y comprenden: salud y nutrición, educación y desarrollo económico. Asimismo, esta medición contribuye a mejorar la comunicación de los impactos generados y desarrolla una gestión adecuada de estos.

Sep 12, 2011

By Armin W. Stuedlein, Youssef Bougataya

Early stage design of driven piles primarily relies on static analysis based on one or a combination of total and effective stress approaches, the latter known as the method to estimate axial capacity. A database of 85 piles driven in the Puget Sound Lowland region and monitored at End of Driving (EOD) and Beginning of Restrike (BOR) was compiled along with capacities estimated using the CAPWAP procedure. Established soil profiles based on borings with standard penetration tests (SPT), cone penetration tests, and geologic maps were matched with their corresponding unit shaft resistance profiles from the CAPWAP procedure and resulted in more than 1,200 observations. In this study, eight new models were developed to predict the coefficients at EOD and BOR, based on the corresponding USCS categorization. Each coefficient model is formulated using a three-parameter exponential function, calibrated to capture the profile of coefficients with depth. These models could benefit the designer by providing them with a simple, empirical model that accounts for soil type and setup in a smooth, continuous function with depth. A parallel analysis was performed to assess the accuracy and variability of the formulated prediction models to facilitate implementation in load and resistance factor design (LRFD). INTRODUCTION The design of the axial capacity of driven piles during the planning stages of a project is typically based on a static analysis approach. The goals of this approach are to predict the components of capacity, consisting of the shaft and toe bearing resistances, and to assess project concept feasibility and preliminary lengths. In most cases, this analysis is based on empirically-developed methods, such as the total stress method, also known as the method (Tomlinson 1987) or the effective stress method known as the method (Esrig and Kirby 1979; Fellenius 1991). Many other methods, such as those based on in-situ test results exist and rely on correlations of blow counts from the standard penetration test (SPT), and cone tip and sleeve friction resistance from the cone penetration test (CPT), to shaft and toe pile resistances (Schmertmann 1978; Meyerhof 1976; Nottingham and Schmertmann 1975; Nordlund 1963; Eslami and Fellenius, 1997; De Ruiter and Beringen 1979). Although these methods were generally developed using data from specific geological regions, they are often recommended in national design manuals (e.g., FHWA, Hannigan et al. 2006).

Jan 1, 2018

By C. Gregory Knight

Adequate planning for the development, operation, and reclamation of a surface mine requires attention to present and future uses of land, both on the mine site and in the mine vicinity. This paper outlines land use implications of surface mining, and suggests procedures that could link mine planning, mine operation, and reclamation to more general land use concerns. Mining is viewed as a temporary use of land that may irretrievably commit land resources away from some future activities, but may allow other uses, some of which may have been impossible without mining. The paper accepts the premise that surface mining should attempt to minimize environ-mental damage and to maximize future alternative uses of land by appropriate reclamation. I. The Effect of Surface 1'1ining on Land Use Surface mining is a temporary utilization of the land most often criticized because the disturbances it creates are of far greater duration than the actual extractive operation, Resource recovery disrupts existing activity on the land, at least temporarily, and

Jan 1, 1977

By R. V. Ramani

The overall objective of this study is to contribute to the reduction of the quartz dust hazard in underground coal mines through a better under-standing of the sources and generation of airborne quartz dust. This research project has included extensive experiments in operating mines for (1) documenting the amount of respirable dust generated, (2) measuring the quartz levels in host materials and airborne dust, (3) analyzing the size consist of the mined product, and (4) establishing the relationship between these various parameters. The results of the study indicate that the amount of dust airborne is a very small fraction of the total (<15 µm) and respirable (<7 µm) dust generated. The quartz contents in the total and respirable airborne dust are generally higher than those in the host material. Quartz content increases with decreasing size of airborne dust. Also, it appears that rock breaks into a different size distribution than coal. The source of quartz for the airborne dust appears to be the roof and the floor material rather than the coal seam itself. No general relationship is found between the Hardgrove Grindability Index and either the quartz content in the airborne dust or the amount of respirable dust. Extended descriptions of the experimental design, the experiments, data analyses and results are presented in this volume. The raw data, the data management computer program and the sampling and safety plan are presented in Volume 2.

Jan 1, 1987

By B. Haugrud, E. McConaghy, M. Collins, G. Smith

"Laterite ore processed by the Ambatovy Joint Venture in Madagascar is primarily limonitic in nature, containing about 40 to 45 wt.% Fe and 1.1 wt.% Ni. The process selected for treatment of this ore considered the behavior and deportment of iron in each step of the commercial flowsheet. Such considerations included nickel and cobalt recoveries, reagent consumptions, liquid-solid separation characteristics, and both intermediate and final product purities. In this paper, the results for the first three years of commercial operation at Ambatovy are compared with the design parameters, with emphasis on the behavior of iron.INTRODUCTION The main component of nickeliferous laterite ore is iron, and the Ambatovy deposit in Madagascar is no exception. The Ambatovy ore is primarily limonitic in nature, containing about 40 to 45 wt.% Fe and 1.1 wt.% Ni. Since the nickel content of the ore is roughly one fortieth that of iron, successful recovery of nickel depends on close control of the behavior of iron in the selected process. Exploration of the Ambatovy area, which is located to the east of Antananarivo, the capital of Madagascar, dates back to 1960, when the Malagasy Service Géologique carried out a limited pitting and auger-drilling program. Phelps Dodge Corporation (now Freeport-McMoRan Copper & Gold, Inc.) was granted the mining rights to the property in 1995 and carried out significant resource definition, environmental assessment and engineering studies between 1995 and 2001 (Chou, Rooke, Williams, & Hanks, 2000). In 2003, Dynatec Corporation, which was formed in 1997 by the merger of Dynatec International Ltd. and Sherritt International Consultants Inc., signed a joint venture agreement with subsidiaries of Phelps Dodge to evaluate the Ambatovy Nickel Project. Dynatec then became extensively involved in the development of the project, including process selection and pilot plant testing in Fort Saskatchewan (Collins et al., 2004, 2005, 2009; Collins & Vardill, 2005). Dynatec acquired 100% of the project in 2005 and a joint venture between Dynatec, Sumitomo Corporation, Korea Resources Corporation (KORES), and SNC-Lavalin Inc. (SLI) was formed shortly thereafter to provide funding for further development. SLI was responsible for engineering, procurement and construction management of the commercial facilities. Sherritt International Corporation reacquired Dynatec Corporation, including 40% ownership in the Ambatovy Nickel Project, in 2007. The current Ambatovy Joint Venture consists of an integrated nickel and cobalt mining, processing, refining and marketing enterprise between subsidiaries of Sherritt (40% owner and mine and plant operator), Sumitomo Corporation (32.5% owner) and KORES (27.5% owner)."

Jan 1, 2016