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By Samer Sadek, Phoebe Cheng, Changmo Kwon, Myat Ohn

BART Facilities Standards (BFS) Structural Criteria is a living document that governs planning, design, and construction of all BART projects. Since its development, the document undergoes incremental changes and updates to reflect policy changes, changes in local, State, or national design codes and guidelines, advancements in engineering and technology, or based on the performance of past built infrastructure. In 2020, the BFS-Structural Criteria underwent a comprehensive update and was released with BFS version 3.2. This paper summarizes the updates to the Tunnels and Underground Structures Section of the Structural Criteria, and provides insights to the basis and logic of the requirements.

Dec 1, 2022

By O. D. Staman

The risk assessment project examines the likelihood of inorganic contaminants from copper dump-leaching operations to contaminate domestic water supplies. The project examines contaminant transport by modeling contaminant movement from the base of a leach pile through the unsaturated zone and into the saturated zone. The modeling effort is unique in that it models infiltration, contaminant transport in the unsaturated and saturated zone combined with geochemical modeling of the unsaturated zone. The project incorporates probability theory to reflect the uncertainty of hydrogeologic parameters.

Jan 1, 1994

By Jerry C. Tien

Changes and the pace of change in China’s coal industry have been extraordinary during the past several years. At least 35 of the 94 former coal bureaus have been restructured into different mining companies and groups. Some of the more productive and efficient ones were further strengthened through consolidation and expansions. And several have even formed, or are in the process of forming, strategic alliances with utility companies, railroads, ports and chemical companies to secure additional reserves and coal sales. In addition, the improvement in coal pricing during the past two years has enabled China’s coal industry to move ahead with some needed changes. Coal mining accidents, though, remain a major concern for the Chinese government. Accidents remain high even though the government has made efforts to shutdown more than 55,000 unlicensed, unsafe small coal operations throughout the country.

Jan 1, 2003

By Ronald W. May

The Lower Cretaceous McMurray Formation in northern Alberta contains bituminous sands interbedded with other sediments which form the reject encountered during mining operations. Grade prediction is based on a combination of geological interpretation, computer modelling and past mining experience. In addition to estimates for ore, an accurate estimate of "waste" or "reject," are required for Mine Planning. This study investigates the ability of point-kriging using geostatistics, to augment the existing data base of drill-holes in a study area on Syncrude's leases. This approach enables the assessment of potential "worst" case - "best" case scenarios within the context of Mine Planning.

Jan 1, 1985

By Zephaniah Varley, Satoshi Akai, Richard Sage, Steve Redmond, Mike Murray, Rohit Shetty, Gerald Skalla

One would be hard pressed to find another project as complex as this one given its configuration, the variety of issues to address and the required construction techniques. Contract C710 is currently under construction as part of Sound Transit’s Link Light Rail, connecting downtown Seattle with Sea-Tac Airport. The paper describes the construction-to-date of the deep mined station under Beacon Hill using the Sequential Excavation Method (SEM). This deep “binocular” station is being mined through some of the most challenging soft ground conditions in the USA. The excavated volume of the station is approximately 60,000 cy (46,000 m3) and the station comprises a variety of geometries and cross sections ranging from 235 sf (22 m2) up to 1,670 sf (155 m2). This underground complex includes platform, concourse, cross-passage and emergency ventilation tunnels together with station egress and ventilation shafts. Various excavation sequences are in use for the different tunnels including the twin-sidewall drifts for the impressive45 ft (13.7 m) wide by 42 ft ( 12.8 m) high concourse cross adits. This station has two train platforms approximately 165 feet (50m) below the surface. This station, constructed in highly variable glacial deposits including water bearing sands and silts approximately 50 ft below multiple perched water tables in an urban setting, creates a very unique and challenging situation. The ground is being managed with various types of ground improvements such as jet grouting and vacuum assisted deep dewatering wells from the surface, and from underground by use of “SEM Tool-box Items” such as barrel vault canopy, grouted pipe and rebar spiling, chemical grout,

Jan 1, 2007

The only significant iron ore deposit in Hungary could be found in Rudabánya. The mine was closed in 1986. The area of Rudabánya was always the home of heavy mining activity. In former times, mainly silver and other non -ferrous metals were excavated.

Jan 1, 2011

By Todd Wanless

This paper addresses the challenges experienced by the designer and three government agencies during implementation of major improvements for the Turkey Creek Tunnel in Kansas City, Kansas. The tunnel serves as a vital stormwater conveyance system for upstream flood control. Major structural deficiencies were identified within the tunnel including complete loss of sidewall and invert. Without immediate attention, complete loss of the tunnel arch could lead to blockage and extensive remedial repairs under difficult conditions. Considering that tunnel flows must be maintained during construction, a phased design and construction process has been implemented to expedite stabilization of the erosion cavities followed by tunnel liner repairs.

Jan 1, 2008

By S. Jayson Ripke, Shane Hoff

Cleveland-Cliffs’ Northshore Mining Company operates a magnetic iron ore (taconite) concentrator and pelletizer in Silver Bay, MN. These are two recent cost reduction projects: 1. Rougher Magnetic Separators were upgraded throughout the concentrator; throughput and recovery were simultaneously improved. 2. Green Ball Roll Screens on one agglomeration circuit were upgraded from 3.5-inch to 2.5-inch rolls. Throughput improved by 24% from 62 to 77 LTPH. Green ball size distribution improved as an added benefit.

Jan 1, 2005

By Z. Mullard

The introduction of social media platforms has ushered in a new era of interaction and information exchange, which impact business-to-society relationships. Mining companies are closely watching these platforms, as the industry takes a cautious approach to control flows of information. This paper explores the risks, challenges and opportunities of using social media, based on a qualitative mixed methods investigation with stakeholders from the Canadian mining industry. Generational and language barriers, misunderstanding and limited motivation from regulators make implementing social media platforms challenging and risky at an organizational level. The benefits of social media include being able to mobilize communities and share information in real time. Despite the challenges, the study found that 62% of mining stakeholders are incorporating social media tools, mostly in an ad hoc manner. Flexible strategies for transparent communication and public engagement are creating new opportunities for information exchange.

Jan 1, 2011

By Robert A. Cummings

A field inventory was made of the mineral, geologic, geothermal, and groundwater resources of three geologically recent lava fields in the desert of Oregon. The term "resource" was applied with care: a "resource" must have particular value or worth, although it need not be economically viable. The spectacular volcanic features of the area have particular scientific and general interest and thus constitute geologic resources. The mineral endowment, mostly occurrences of low unit value such as stone and cinders, in large part are not resources, due to market conditions, regulations, and other factors. These and other conclusions will be used by the Bureau of Land Management in its multiple land use planning process for the area.

Jan 1, 1980

By Richard D. Lang

The paper provides an overview of the activities which culminated in the decision to construct a major diamond mine in the north west of Australia. It presents a broad summary of the geological, mining, processing and marketing work which has been required to bring the project to the construction phase. The implications of the development for the world industrial diamond market are also discussed.

Jan 1, 1985

By J. B. Hiskey

The principle oxide minerals of molybdenum are wulfenite (PbMoO4), ferrimolybdite (Fe2(MOO 4)3.nH2O), powellite (CaMoO4), and ilsemannite (Mo304). Wulfenite is found in Arizona, New Mexico, Nevada, Utah, California, and Montana. It is also found in the states of Sonora and Chihuahua, Mexico. Prior to 1915 wulfenite ores were the primary source of molybdenum. The solubility of wulfenite in hot sodium sulfide was first noted by Bonardi(1) during attempts to sulfidize wulfenite material prior to flotation. He identified lead sulfide and soluble sodium molybdate as reaction products. Bacon (2) sulfidized wulfenite in preparation for flotation and by X-ray analysis found the reaction product to be lead sulfide. Holmes(3) made an extensive investigation of the extraction of molybdenum from wulfenite concentrates by leaching. Nearly 100% molybdenum extraction was possible from -100 mesh samples leached for 15 min with 10% sodium sulfide solution at room temperature. Molybdenum extraction from -100 mesh samples after leaching 30 min at a temperature of 45°C using 2, 4, and 6% sodium sulfide was about 32, 79, and 98% respectively. The extraction showed little sensitivity to time, temperature, or particle size using 10" sodium sulfide solution.

Jan 1, 1976

By K. H. McDaniel

The Waste Isolation Pilot Plant (WIPP) is adding a third fan to operate in parallel with, and supplement, its two existing main fans. An engineering analysis conducted in 1995 identified the need for improved system availability and efficiency. The WIPP, located near Carlsbad, New Mexico, is a U.S. Department of Energy (DOE) Carlsbad Area Office facility designed to permanently dispose of U.S. defense-generated transuranic waste in a deep bedded salt deposit. Engineers at the WIPP performed a feasibility analysis for either modi tying, supplementing, or replacing its two main mine fans. Since the centrifugal fans were installed in 1988, multiple operational and performance concerns have been identified. A comprehensive engineering study was conducted (McDaniel, et al., 1997) to: identity and quantity operational concerns, evaluate possible alternatives, and recommend an optimum solution. The study indicated that adding a third single-duty centrifugal fan similar to the two existing fans, and equipping that fan with Inlet Van Controls (IVCs) was the best choice. This alternative provided the most desirable combination of operational readiness, and improving system performance. The fan installation project accommodates several operational and scheduling constraints. WIPP is scheduled to receive waste in May 1998. This milestone is proceeded by an operational readiness review. Fan installation could not be allowed to compromise the WIPP's ability to declare facility readiness and had to minimize operational disruptions during the system tie-in. All engineering for the project is completed and physical modifications started in July 1997. The project was completed in 1998.

Jan 1, 1999

By Steve Kral

The mining industry in northern Ontario is known mostly for its huge nickel deposits. Inco’s and Falconbridge’s nickel mines in the Sudbury Basin are the best known. And with nickel prices being what they are, interest in the region continues. And how. Inco and Falconbridge want to merge. Teck Cominco wants Inco, but without Falconbridge. Xstrata made a hostile bid for Falconbridge, which Falconbridge rejected. And, in June, Phelps Dodge trumped them all when it made an approximately US$40-billion friendly offer for Inco and Falconbridge in a two-part deal.

Jan 1, 2006

By W. Hermülheim, J. Brune

"This paper analyzes mine emergency management and rescue practices in German underground coal mines and compares them to those used in the United States. The German mining industry has developed these practices over more than 100 years, and they have successfully managed numerous fire, water inundation and ground control emergencies using these techniques. The authors interviewed German mine emergency professionals about rescue team and emergency operations. These operations were then analyzed to determine which of these German principles would be of interest to United States mine rescue teams. Implementing these programs into United States mine rescue and emergency operations was analyzed. INTRODUCTION Coal mining has become much safer industry than it has been in the past. Advances in safety and health regulations and company polices have improved working conditions for miners all over the world. Even with these advances there is still a need for continued attention to safety and health. It is also important for mine safety professionals to observe practices and procedures in other countries and cultures and learn what and how to apply this knowledge in their own systems. Coal mine rescue has been an integral part in improving coal mine safety. Mine rescue procedures have evolved with time, experience and technology development. Today, coal mine rescue teams are still needed and must be continually trained and prepared for any mine emergency. Although it is hoped that improved mine safety policies and practices will eliminate coal mine disasters in the future, accidents remind us that disasters can still happen today. In May 2014, Turkey experienced a severe coal mine disaster where 301 people were killed [G.Tuysuz, 2014]. Our industry must learn from these incidents, focusing on disaster prevention and making improvements in mine rescue operations. Mine rescue procedures differ from country to country due different regulatory environments and different historical evolution of emergency response. Sharing practices and procedures from one country to another enables learning from different experiences and cultural backgrounds. Sharing is also a way of preserving information, identifying and learning best practices."

Jan 1, 2015

By Biswajit Samanta, Pranjal Pathak

This article presents a customized genetic algorithms (GA) with new crossover and mutation operators to solve the short-term production scheduling problem of multi-mine mineral value chains (MVC). The preceding problem consists of determining the extraction sequence and destination allocation of blocks from all the mines collaboratively while closely meeting the quality and quantity requirements of the processing units subject to relevant technical and operational constraints. The short-term production scheduling is carried out at shorter scales wherein the operations are modeled in a great detail with large number of constraints. This makes the industry-scale instances of the problem computationally intractable for standard mixed-integer programming (MIP) solvers. Thus, a GA-based heuristic approach is developed to obtain nearoptimal solutions to the large-scale instances of the problem in a reasonable amount of computational time. Computational experiments show that the developed GA-based method is a promising way to handle industry-scale instances of the problem. Moreover, the sensitivity analysis on various parameter combinations of crossover and mutation operators indicates that the customized global mutation operator, when used in combination with the customized crossover operators, took on average 12.5% less time than the customized local mutation operator to converge to a solution.

May 21, 2022

By H Arvidson, Rondinelli Sousa, Nic Pollock, Cesar Carrasco, Boz Elloy

Global public mineral reporting codes have driven strong governance of public disclosures of minerals information. Recently, we have seen an increase in disclosure of information related to Environmental, Social and Governance (ESG) issues, and governance of ESG information in mining companies has arguably reached a similar level of governance and diligence afforded mineral reporting. We define Resource Governance as the conjunction of environmental, social and minerals governance. A modern systems approach to Resource Governance, which combines mineral and ESG information, would provide not only reporting and governance capability, but also has the potential to sense/respond, predict, and manage ESG risks.

Feb 1, 2024

The trend for using larger equipment in open pit mining to achieve cost effectiveness raises the question about the optimum economic point of scale in the current world of globalization. The present paper treats this question through the prism of a new methodology of assessing the impact of the size of production equipment on the economic outcomes of coal mining ventures. The methodology incorporates a production scheduling optimization model that implements both principles of mine planning, coal quality optimization and waste deferment. The implementation of the waste deferment principle dealing with the spatial and time aspects of the mine sequence arrangement allows the adequate modeling of the optimality of production equipment scale through the use of mine investment parameters, such as, purchase and ownership costs and discounted cash flows analysis. A case study is provided to illustrate the applicability of the new methodology.

Jan 1, 2004

By Narendra N. Khatri, Michael Deutscher, Jozef F. Zurawski

Five sewer connections were required to divert Combined Sewer Overflow (CSO)from existing outfalls to an old underutilized large diameter brick sewer (the Easterly Interceptor). The connections were part of an on-going CSO control program by the Northeast Ohio Regional Sewer District (NEORSD) in the City of Cleveland, Ohio. Each connection was made by pipejacking and hand-mining a fiberglass-reinforced polymer (FRP) pipe through soft glaciolacustrine clays and silts. Jet grouting was utilized to stabilize the soils and fill the voids surrounding the interceptor prior to making the underground connection. Reinforced concrete liners were constructed inside the aging brick sewer to provide structural stability during ground improvements and connection work. The project also involved micro tunneling two approximately400 foot lengths of FRP pipe through soft ground using a slurry pressure balanced machine.

Jan 1, 2005

By D. S. Kimbal

The McCoy/Cove mine is located 48 km (30 miles) south of Battle Mountain, Nevada, USA, in the Fish Creek Mountains at an elevation of 1548 m (5080 ft), see Figure 1. Joseph H. McCoy first discovered gold at this location in 1914. This discovery led to the Gold Dome Mine which produced the first gold from this area in 1928. After the Gold Dome era, the land remained relatively dormant until Houston oil and Minerals Corporation purchased the claims from the Summa corporation and defined an ore body at the present day McCoy pit. In 1986 Tenneco Minerals (formerly Houston oil and Minerals corporation), sold the McCoy mine and adjoining claims to Echo Bay Minerals corporation. The Cove ore body was discovered soon after the sale to Echo Bay. Echo Bay expanded the heap leach operation and built the present mill which began processing ore in the fall of 1989.

Jan 1, 1993