Search Documents

By Yasutaka Izumi, Tuneyoshi Funasaki, Keizou Miki, Makoto Kanai

INTRODUCTION The Tokyo metropolitan region, inclusive of the three neighboring prefectures (Kanagawa, Chiba and Saitama), has the highest concentration of population and industry in Japan; with an area of 13,500 km2 or only 3.6 percent of the national land, but a population of 31.8 million or 26 percent of the national total, and a Gross Regional Product (GRP) of146 trillion yen (US$1.33 trillion) or 36 percent of the overall GDP of Japan as of 1990. Tokyo Bay, embraced by the metropolitan region as shown in Figure 1 (a), (b), is open to the Pacific Ocean as a marine gateway and is ringed by large cities and coastal industrial zones together with port facilities, all constituting a concentration of prime importance for socio-economic activities. The Trans-Tokyo Bay Highway (TTB highway), which crosses Tokyo Bay and provides a direct transportation link between the west and east sides of the bay, has long been a sort of “dream-come-true” project in Japan. As shown in Figure 2, linked to the Tokyo Bay Shore Highway, Metropolitan Inter-city Expressway, Tokyo Outer Ring Road, Tateyama Express-way, and others, it will play an important role as an integral part of the regional highway network to help promote spatial redistribution and multi polarization of urban functions, thus strengthening cooperation between cities and restructuring the metropolitan region. The TTB Highway is a project of 15.1 km in length designed as a toll highway to cross the bay by tunnel and bridge, and will require ten years to complete at a total cost of more than 1,438 billion yen (US$13.077 billion). Following more than 20 years of feasibility and environmental assessment studies, construction of this giant offshore highway project commenced in May 1989 as the first large-scale highway project with private-sector participation under the prevailing Road Law in Japan, and is now steadily proceeding toward the goal of completion in fiscal1997. This report outlines the entire TTB Highway project, including the waterproofing measures against high water pressure and the rapid construction method applied in the construction of shield tunnel sections.

Jan 1, 1997

By L. Harris

The Yanacocha project is the first foreign investment in Peruvian mining since Cuajone during 1976. Three years after the project began, it has become the largest producer of gold from heap-leach operations in the world and the top producer in Latin America. The success of Minera Yanacocha SA (MYSA) opens a new chapter in Peruvian mining with the exploitation of its widely spread gold deposits. And it has attracted the interest of foreign investors in Peru’s mineral resources. Construction began on Aug. 1, 1992. The first gold bar was poured on Aug. 7, 1993 from ore from the Carachugo Mine. During 1993, Minera Yanacocha produced 2.5 t (81,000 oz) of gold and 9.4 t (304,000 oz) during1994 (40% above budget). Production was expected to exceed 15.5 t (500,000oz) during 1995 with the start-up the Maqui Maqui Mine.

Jan 1, 1996

By D. Brunner, G. R. Baiden, H. J. Yazici

System simulation is an increasingly popular technique for analyzing and improving existing as well as newly designed underground mining operations. An engineering firm that specializes in simulation helped a major metals producer build a long-range planning model of an existing underground mine. Subsequently the team adapted this model to assess technology alternatives in the design of a new mine. The two models differ in the level of detail used for modeling the development process. This paper discusses the differences in approach between the models along with the experiences gained and challenges faced during the construction and use of the models.

Jan 1, 1999

By Andrew Finney

INTRODUCTION The Sacramento Regional County Sanitation District (SRCSD) serves unincorporated areas of Sacramento County, parts of the cities of Sacramento and Folsom, and the cities of Citrus Heights, West Sacramento, Rancho Cordova, and Elk Grove. SRCSD maintains 145 kilometers (km) (90 miles) of interceptors that convey a combined total of 0.6 million meters3 per day (160 million gallons per day) or more of waste-water, with additional miles of sewer interceptors that are scheduled to be built by 2020. Wastewater is conveyed to the Sacramento Regional Wastewater Treatment Plant in the southwestern portion of the County, also managed and operated by SRCSD, in interceptors with diameters as large as 3.0 m (120 inches.) As part of its overall expansion program, SRCSD has constructed a number of major interceptors over the last few years with tunneling methods due to concerns associated with either the impacts of open cut construction in an urban environment (traffic, safety, noise, environmental concerns) or the need to achieve a crossing of a stream, river, or transportation corridor. This paper focuses on a specific issue that affected construction of the Upper Northwest Interceptor (UNWI) Sections 3&4 project, located at the northern limit of the SRCSD service boundary and within the limits of the City of Sacramento. This project involved the construction of 3.2 km (2 miles) of 2.1-meter (84-inch) and 2.4 km (1.5 miles) of 1.7-meter (66-inch) diameter reinforced concrete pipe (RCP) using MTBM, EPBM, and 3.3-meter (130-inch) two-pass TBM methods. The owner elected to install the RCP using tunneling for a number of reasons including a desire to avoid traffic impacts in a dense urban corridor, to minimize disturbance to the neighborhood, and to avoid potential dewatering-induced settlement issues along the western one-third of the project. For the western portion of the alignment the 2.1-meter (84-inch) reinforced concrete interceptor pipe was to be installed using a 2.7-meter (105-inch) earth pressure balance machine (EPBM). No external dewatering of shafts or tunnels was permitted for reasons of concern about settlement, discussed previously. At the intersection of Elkhorn Boulevard and Natomas Boulevard (at the extreme northwest corner of the project) the 2.7-meter (105-inch) EPBM tunneled past a recently constructed 11-million liter (3-million gallon) water storage reservoir, passing within 3 meters (10 feet) of the tank?s shallow foundation while tunneling through clean sands with a shallow groundwater table. The paper will discuss the implemented solution to mitigate additional settlement risk that was developed as a joint collaboration between the owner, CM, designer, and contractor.

By P. Harris, G. Groenmeyer, L. Parolis

The effect of molecular weight, charge and the presence of the cations Ca2+, Mg2+and K+ on the adsorption of carboxymethyl cellulose on pure talc obtained from Balmat, New York have been investigated. Higher adsorption densities were obtained in the presence ofCa2+ and Mg2+ ions than with K+ ions and higher ionic strength solutions resulted in higher adsorption densities. Changing the molecular weight did not influence the adsorption however increasing the charge (DS) of the polymers resulted in lower adsorption densities.

Jan 1, 2004

By C. R. Hairfield

With ever rising energy costs, it is increasingly important for mines to operate with energy efficiency. As a large portion of a mine?s energy consumption is often attributed to the operation of mine ventilation fans, maintaining an efficient ventilation system is a critical pro-active way for mining companies to reduce power costs. A common way to measure a mine?s ventilation system efficiency is to calculate the volumetric efficiency, which is simply a calculation of the percentage of total mine air that is usefully employed for production. The purpose of this study is to document a nationwide comparison of the volumetric efficiency of U.S. underground coal mining operations. The results will aim to show just how efficient today?s coal mine ventilation systems are and what factors may be causing their various efficiencies and inefficiencies.

Jan 1, 2009

By C. A. Young, R. G. Robins, E. J. Dahlgren

The formation of copper thio-complexes in sulfide solutions has been recognized for many years and the measured solubilities of certain copper sulfide minerals attributed to these complexes. Attempts to model this system have proposed either copper(I) or copper(II) thio-complexes, and these have been incorporated into computer programs for generating stability diagrams for the copper-sulfur-water system in order to delineate the region where the reductive dissolution of copper sulfide minerals is likely. In this paper it is proposed that the dissolution of copper from both ore bodies and sulfide tailings can be explained by the formation of the cupro-thio-complexes under anaerobic conditions. Stability diagrams are presented to depict the region and extent of the solubility.

Jan 1, 2001

By P. van der Veen

The objective of this paper is to analyze the evolution of the strategic drivers of the mining sec-tor over the last half century, which has been guided by a varying and expanding list of motivations. While companies cannot survive for long unless they are making profits, the strategic drivers of the industry have gone far beyond profits since at least the mid-1970s when environmental concerns began to be taken seriously. For the most part, these forces have followed global trends and public opinion, but they have been shaped and magnified by the significant, often dominant role that the mining sector plays in many economies. While the mining sector used to be primarily motivated by the first pillar of sustainable development -i.e. the economics pillar-, in the 1970s the second environmental pillar became an important factor in decision making, and in the 1990s the third social pillar emerged as a major driver.1 The entrance of new strategic drivers has also had considerable impact on technological and organizational developments in the mining industry; however, technological changes, driven by cost reduction considerations, have in turn impacted the strategic drivers of the industry, resulting in the need for further technological and organizational developments.

Jan 1, 2007

The inquiry into the explosion at the Moura No. 2 Mine in August 1994 recommended -?Emergency procedures should be exercised at each mine on a systematic basis, the minimum requirement being on an annual basis for each mine.? (Windridge et al. 1996). In December 1996 the ?Approved Standard for the Conduct of Emergency Procedures Exercises? was published and has been subsequently revised (Queensland Department of Mines and Energy Safety and Health Division 1999). This document provided guidelines for conducting mine site emergency exercises as well as the requirement for a test of state-wide emergency response by holding a Level 1 Mine Emergency Exercise at one mine on an annual basis. From 1998 to date (January 2008) ten Level 1 Mine Emergency Exercises have been held in Queensland, Australia. This paper discusses each of the exercises conducted to date as well as the logistics, scenario preparation, planning and organising required to conduct emergency exercises at this level.

Jan 1, 2009

By James W. Clark

This paper is a description of certain geologic aspects of the Inspiration mining operation. It is not a geologic description of the Inspiration deposit nor an exposition of all the geologic work involved in the development and exploitation of the deposit. A few specific examples of the application of geology and geostatistics to the mining process are given to illustrate the progress that has been made in making the Inspiration Mine more efficient and cost effective, and a statement of the philosophy of geologic applications is offered.

Jan 1, 1984

By K. N. Han, N. S. Kim, H. Yoon, J. S. Sohn

The leaching behavior of silver and silver oxides in ammonical solutions has been studied. The current study is concerned with an effective recovery of silver from secondary sources such as spent silver batteries. Silver associated with these batteries appears in various forms including metallic silver, argentous oxide, Ag2O and argentic oxide, AgO. The leaching behavior of metallic silver in ammoniacal solution has been studied using an electrochemical mehtod. Oxidants used in this study include hyperchlorite, hydrogen peroxide, bromine and iodine. Results on cyclic polarization and Tafel plots on the silver anode in ammoniacal solutions are presented and the results are discussed. The dissolution rate of metallic silver in ammoniacal solutions is also compared with those of silver oxides.

Jan 1, 2002

By N. C. Trivedi

Natural calcium carbonate, commonly known as limestone is an abundant resource pretty much worldwide. Calcium carbonate occurs naturally as the main constituent of chalk, limestone, and marble. One of the unique characteristics of this abundant mineral is its versatility. Major markets for calcium carbonate are: paper, plastics, caulks and sealants, carpet backing, paint, and food additives. This broad spectrum of consuming industries has warranted producers of this industrial mineral to be innovative and quality focused simply to meet the ever increasing demands for performance. This need for improving performance of calcium carbonate has led to the development of new sources of calcium carbonate, natural as well as synthetic.

Jan 1, 2002

By L. B. McConville

The general term "tar sand" has been used to describe sand containing varying amounts of dense, viscous petroleum. Deposits of tar sands have been found throughout the world, often in the same geographical area as conventional petroleum. The largest one by far is known as the Athabasca Tar Sands, and is located in the province of Alberta, Canada. Actually a group of three deposits, these particular sands underlie an aggregate area of more than 12,000 square miles. Current estimates place the contained raw petroleum at about 700 billion barrels, from which as much as 300 billion barrels of synthetic oil may be recoverable under presently developed technology. For comparison, this latter quantity is roughly equivalent to five times the combined total of U.S. and Canadian crude oil reserves. With the ever-widening gap between energy supply and demand, attention is being directed to all possible energy sources - both developed and underdeveloped - and certainly the Athabasca Tar Sand deposit is one of the more important ones to merit such attention. This paper will review some of the more significant developments and attempt to place in perspective the role that this source of energy could possibly be expected to play in the foreseeable future.

Jan 1, 1974

By Marvin V. Damm, Lloyd C. Venburg, Dan Sokol

Analytical and computer models are used to evaluate information obtained from existing data and investigation programs so mine water control systems can be designed and developed. These models allow the geohydrologist to predict the amount of groundwater inflow and the impact of dewatering and stream diversion on the hydrologic regime, and to determine the schedule and equipment needed for mine dewatering. This article describes uses of the model and the essential components necessary to construct an effective and practical one. Hydrologic models are constructed to determine the extent that mining activities will affect the ground water and surface water hydrologic regime. These models range from basic analytical, mathematical models to the more sophisticated finite difference and finite element groundwater models. Many factors determine the degree of sophistication, including the mining stage, the complexity of the hydrologic regime, the mining process, and regulatory requirements. Model Uses The geohydrologist and engineer construct models so the entire ground and surface water handling and supply system can be integrated and optimized. These models can provide the following data: • Information for water balance studies-the entire hydrologic regime for the area, including precipitation, transpiration, evaporation, infiltration, runoff, and the effect of geologic features. • Data on seepage rates during mining. • Information to design the depressurization and dewatering system, including water well spacing, location of sumping systems, need for grout curtains, and possible horizontal drain and underdrain locations. • Data needed to schedule dewatering and mining operations. • Prediction of initial and long-term impacts of mining and dewatering, including local and areal drawdowns, effects on existing wells, and modifications to the surface-subsurface hydrologic regime. Potentiometric surface maps and hydrographs can be prepared from these data. • Prediction of the effect of discharge from the water control system on the surface hydrology and data input to design systems for water discharge, storage, recharge, or reinjection. The results of a computer study that illustrates the effect of dewatering and reinjection into an aquifer to confine the cone of depression are shown on the accompanying figure. • Information to forecast potentiometric surface recovery after mining ceases. The accompanying figure shows the pumping and reinjection rates in a program that is adequate to dewater a mine and permit the recovery of potentiometric levels to approximate premining levels after mining ceases. • Documentation and design information for monitoring systems to be installed during all mining phases. • Water quality predictions and geochemical changes, including the possibility of brackish or saline water intrusion because of extensive dewatering or depressurization operations. • Documentation and data for acquiring permits from regulatory agencies. Model Input Program For any model to be effective, detailed hydrologic and geologic data must be gathered from a review of existing information and from an investigative program. These data should cover entire model limits. Data updating, revising, and refining should occur as new information is received from the investigation and monitoring programs, and from the mining operation as it progresses through the pre-mining, mining, post-mining, and reclamation

Jan 8, 1982

By S. A. Shuey, P. Taylor

The recycling of electronic waste (e-waste) tends to be a rather complex undertaking when considering the intimate bonding of materials in the average printed circuit board. The development of a recycling process is further complicated when considering the wide variety of products being generated under the heading of “electronics” as well as the constant change in materials of construction coupled with the speed at which electronics are changing. CSM researchers have undertaken a survey of the current state of pyrometallurgical processing of e-waste. This base-line will set the stage for the development of new recycling technology at CSM.

Jan 1, 2004

By J. Cole

The Morenci concentrate leach plant construction was completed and successfully commissioned in October 2007. The plant was designed to operate at medium temperature, 160ºC and pressure, 2,100 kPa. The concentrate leach plant utilized many innovative design features. This paper examines the first year?s operation, the challenges, the successes and the lessons learned. The future plans for Morenci concentrate leaching will also be presented.

Jan 1, 2009

By Joseph L. Young, Richard A. Bohling

To keep Homestake's Bulldog Mountain silver and lead mining and milling operation in southwestern Colorado workable, natural ground water and decant water from the mine's sand backfilling operation must be continually pumped from the workings. Left untreated, this water exceeds maximum allowable levels for various contaminants that may be discharged to the environment. To comply with regulations, a National Pollutant Discharge Elimination System (NPDES) permit was obtained and a mine water treatment plant for heavy metals removal was constructed in 1977. Due to equipment capacity and operational problems, and the lack of on-site technical personnel and analytic equipment, the first water treatment plant could not consistently meet permit limits. In 1979, Homestake entered into a consent decree with EPA and the Colorado Department of Health, calling for the construction of a water treatment facility to meet NPDES permit limits. Initial construction began in the spring of 1980 and the plant now produces effluent acceptable for discharge.

Jan 12, 1981

By C. Laughton

The Deep Underground Science and Engineering Laboratory (DUSEL) is to be constructed at the defunct Homestake Mine, in South Dakota. As a cornerstone of DUSEL?s research program, it is intended to conduct experiments into the fundamental nature of neutrino and proton particles. The experimental apparatus required to con-duct these experiments will be housed in large rock cavern(s) sited at depths of over a kilometer. As conceived, these cavern(s) are planned to have mined volumes of up to half a million cubic meters, and spans of approximately 50 meters. The paper will describe key end-user requirements, and outline the in situ rock conditions and mine site constraints that are likely to play determinant roles in identifying candidate sites and developing cost-effective design options(s).

By Tim O’Neil

What prompted the merger of the two long-established American Mining Congress/National Coal Association (AMC/NCA) groups that combine the coal, hard-rock, industrial- and agricultural-minerals sectors of mining? Both associations have been facing similar stresses for several years - structural changes in their respective industries, the changing personality and role of government and well-financed and organized opposition groups. In 1993, the AMC board of directors undertook efforts at reorganizing the association. One board member, who serves on both boards, suggested it might be time to give serious consideration to merging the organizations. This is an idea that had been discussed more or less informally at least three times during my tenure at NCA. Negotiations toward a merger began after that and were consummated in February of this year.

Jan 1, 1995

By Allen W. Hatheway, John A. Albritton, Lloyd B. Underwood

Missouri River Division (FORD), U.S. Army Corps of Engineers (COE), has completed (October 1982) a study for the U.S. Air Force Ballistic Missile Office, in which desireable and needed changes in contracting methods for underground construction were identified. Due to the importance of geotechnical considerations in such construction, a good number of the resulting recommendations relate to geotechnical considerations. Corps contracts have traditionally served as models for contract documentation by public agencies and in private enterprise. Several standard features of present-day contracting methods were Corps innovations. Corps officials are generally in agreement with the recommendations of the Better Contracting reports published by the U.S. National Research Council (NAS/NRC), through its U.S. National Committee on Tunneling Technology (USNCTT). However, the findings of the 1982 MRD study indicate that additional changes are warranted for underground construction contracting methods; changes that deal specifically with site geological conditions, both known and to be reasonably anticipated, as well as with their associated impacts on construction. The 1982 MRD report identifies the need for nine specific improvements in geotechnical aspects of contracting; improvements based on recognition of geological conditions.

Jan 1, 1983