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By Tsunenori Shibata, Kazunori Jimbo, Kaoru Toya, Masafumi Matsumoto, Jinya Mitsui, Toshinori Tsuji

"The Toyama Line is under construction as a natural gas pipeline with a length of 102 km from Itoigawa City to Toyama City. A 2 km-long tunnel section of the pipeline that we are reporting here is being excavated in a mountain area away from an urban area. The geology under which the tunnel is constructed is collapsible fractured breccia slate and Holocene sandy soil. Other tunnels of the Hokuriku Expressway and Hokuriku Shinkansen are in service above the tunnel route. From the starting shaft on Toyama side, conventional tunneling was adopted to facilitate excavating the base rock layer and maintain enough distance from the Hokuriku Expressway tunnel. From the starting shaft on the Itoigawa side, TBM tunneling was adopted to cope with the unconsolidated soft ground for a 200 m-long section from the shaft. We will discuss the issues and countermeasures concerning the selection of a tunnel route and excavation methods, performance of both conventional and TBM tunneling, and underground connecting of these tunnels excavated by conventional (NATM) and TBM methods under a high groundwater pressure up to 1.2 MPa. INTRODUCTION AND BACKGROUND The International Petroleum Exploration Teiseki Co., Ltd. (INPEX) is constructing a high-pressure main pipeline network in the Toyama Prefecture area to promote the use and reliable supply of natural gas as shown in Figure 1. As part of the Toyama line project that has a total length of 102 km, A-1 construction, the nearest section to the tunneling starting point in Itoigawa City, where various tunnel excavation methods have been adopted to install the high-pressure pipeline 20 inches in diameter, a 2 km tunnel in the A-1 construction section discussed here is to be excavated by conventional and TBM methods in a mountain area. Based on environmental studies such as traffic jams due to frequent traffic of heavy vehicles disposing of soil, and the effects of dust, noise and vibration during construction, we selected the route to install the gas pipeline in a mountain area as shown in Figure 2, where the impact on the surrounding environment could be minimized."

Jan 1, 2016

By Janine L. Beazley, James H. Kyle

The effects of pH, pH modifier (lime or caustic soda) and cyanide on the pulp rheology of a number of ore types ranging from highly siliceous to highly kaolinitic has been investigated. All experiments were performed in fresh water at solids concentrations of 25 and 45% solids and in the pH range 6 to 11. The kaolinitic ores exhibited greater changes in rheology with pH and calcium ion concentration than did the siliceous ores.

Jan 1, 1989

By Dennis Asmussen

The peatlands of the U.S. and Canadian parts of the Upper Great Lakes region have a long history of modest utilization in agriculture, forestry, horticulture, and as natural undisturbed areas. Only recently have they been assessed as potential sources of non-renewable or renewable energy. This new interest in peatlands, should current proposals be realized, might mean the commitment of millions of acres to energy production purposes. The magnitude alone of this potential utilization of peatland signals the possibility of substantial environmental disturbance, local resource shortages, resource use conflicts, and social and economic change. Peat- land resource managers in the region are just beginning to weigh the advantages and disadvantages of large-scale peatland utilization. The Minnesota Department of Natural Resources has made a considerable effort to study peat resource management issues and will shortly make recommendations to the state legislature regarding utilization alternatives. What follows is a general discussion of peatland utilization and management trends in the region with a focus on Minnesota and its peatland management efforts.

Jan 1, 1980

By Terry I. Mudder

Metal complexed cyanides in wastewaters form as a result of interactions of free cyanide with metals present in the wastewater and exhibit varying degrees of stability, toxicity, and treatability. Thiocyanate, a pollutant commonly found in cyanide bearing wastewaters, is formed through the interaction of free cyanide with sulfur containing species (i. e. pyrrhotite) both present in the wastewater. In certain industrial processes, such as the beneficiation of gold and silver, cyanide is an essential reagent. Since free cyanide, complexed cyanides, and thiocyanate are potentially toxic to humans and aquatic organisms, these compounds must be removed from wastewaters prior to their discharge into surface or ground waters serving as potential potable water sources, marine or fresh water habitats

Jan 1, 1984

By K. J. Bruxvoort

Background ground water quality is often used to drive remediation programs at sites with waters affected by mining activities. In the past these levels were sometimes chosen without rigorous statistical and geochemical analysis. A probability distribution approach was used at the Sweetwater Uranium Project to separate a large set of geochemical data into populations that represent contributions from different sources. Natural background populations were identified for major ions, metals, and radionuclides, and were submitted to the Nuclear Regulatory Commission to modify the extent of a Corrective Action Program and to establish control limits for future monitoring.

Jan 1, 1998

By Robert M. Stevens, Arnoldo Acuña

INTRODUCTION In the early 1950s, underground miners and tunnel¬ing contractors were experimenting with ways to supple¬ment or eliminate track-bound loading and hauling equipment. Diesel-powered crawler and rubber-tire mounted front-end loaders and trucks designed for use on the surface were being modified and tried with limited but encouraging success. Miners began working with interested manufacturers to explore the develop¬ment of vehicles specifically designed to meet the de¬mands and constraints of underground material han¬dling. By the mid 1960s, load-haul-dump (LHD) vehicles were firmly established as a fundamental part of what has become known as the "trackless" mining concept, used in many mines and many countries around the world. The flexibility, mobility, and versatility of these units have given the industry a useful tool and have added new dimensions to mine development and produc¬tion. Many old mines have been redesigned to accom¬modate these trackless vehicles, and few new mining plans have failed to find some use for the concept during some phase of development and production. By 1977, several manufacturers in several different countries were producing a variety of LHD vehicles to meet the growing worldwide demand. GENERAL DESCRIPTION LHD vehicles combine certain characteristics of conventional front-end loaders and dump trucks, spe¬cifically designed for materials handling in underground mining and tunneling. The design intent is to provide one vehicle with one man, with the vehicle loading itself, hauling the load over level or inclined haulageways, and dumping the load. A typical production cycle of the most popular units has the operator driving the vehicle forward, forcing the bucket into the muck at or near floor level, and using the tractive effort of the vehicle and the prying action of the bucket to roll out and tilt back the load as shown in Fig. 1. With the bucket rolled back into the carrying position on the boom and the boom resting on the main frame of the vehicle, the load is hauled (trammed) to the dump point as shown in Fig. 2. At the dump point, the boom is raised, the bucket is rolled forward, and the load slides out as shown in Fig. 3. After dumping, the bucket is rolled back to the carrying position, the boom is returned to rest on the main frame, and the unit is driven back to the loading point for another load. There are two other types of LHD units that are slightly different in the cycles that they perform. One uses a hopper arrangement carried on the front of the machine, with a small bucket mounted ahead of the hopper. Several passes with the small bucket load the hopper, which is dumped by opening its floor. Al¬though this concept is several years old, it has gained less than 0.5% of the total market. The most recent LHD concept differs in that it has one bucket nesting inside another. The smaller inner bucket is loaded first, and it is then tilted back and above the larger bucket. When the larger bucket has been loaded, it is rolled back, and the total load is trammed to the dumping point. The dumping operation tilts the buckets in the reverse order from that of the loading operation. The impact of this new concept on the mining industry has not been measured yet. This chapter concentrates on the LHD vehicles employing the cycle described by Figs. 1 through 3, since these LHD units constitute an estimated 99% of the units in current use. MAIN VEHICLE FEATURES In general, the LHD vehicles available from most manufacturers share the same basic features.

Jan 1, 1982

By Stephen M. Voynick

Two hours driving time west of Denver, CO and 21 km (13 miles) north of Leadville, Bartlett Mountain rises 4,065 m (13,337 ft) high in central Colorado's Tenmile Range. Bartlett Mountain is one of Colorado's most recognizable peaks, especially when the late afternoon sun casts a surreal, reddish light across its most prominent feature - the Glory Hole. This is a gaping, half-mile-wide, 245-m- (800-ft-) deep crater. Created by subsidence from 60 years of massive underground mining, the Glory Hole is a monument to the Climax Mine, one of the great achievements in American mining and metallurgy. For most of this century, the name Climax has been synonymous with brilliant mining engineering, innovative metallurgical research and entrepreneurial promotion of a once-obscure metal - molybdenum. Climax overcame an array of economic, technological and social problems to become a model for underground development of massive deposits of low-grade ores. It is one of the few mines in the world where cumulative production is measured in the billions of dollars. The Climax mineralization was emplaced 30 million years ago. Magmatic intrusions formed a large, mineralized stockwork within the granite country rock of Bartlett Mountain. Associated hydrothermal events forced superheated metal- and quartz-rich solutions through fracture zones, silicifying the country rock and depositing huge amounts of molybdenite, or molybdenum disulfide. The mineralized rock, a light gray, finely crystalline, silicified granite, is laced throughout with blue-gray quartz veinlets containing molybdenite. Although the richest ores graded only about 1% molybdenite, the Bartlett Mountain deposit contained more than 2.7 Mt (3 million st) of elemental mo- lybdenum.

Jan 1, 1997

By W. J. Dolinar

The U.S. Bureau of Mines implemented the Fe2+ /Fe3+-SO2 anode reaction in a Cu electrowinning cell with full-size electrodes. Electrowinning was conducted using industrial electrolyte at 258 A/m2 (24 A/ft2) and 40 'C. Manifold injection of electrolyte provided circulation between the electrodes. Five-day operation using an optimized manifold gave an average cell voltage of 0.94 V at 89% current efficiency, which amounted to an energy savings of 2.82 MJ/kg (0.355 kW-hr/lb) compared to conventional electrowinning. Acid misting was completely eliminated, and SO2 concentration 23 cm (9 in.) above the cell averaged 0.06 ppm.

Jan 1, 1995

By Michael Murphy, Gamal Rashed, Brent Slaker

Many underground stone mines in the United States operate on multiple mining levels. The effects of interburden thickness, pillar offset between mining levels at various depths of cover, and in situ stress conditions are poorly understood. Pillar offset is the degree to which pillars are not columnized or stacked. In this study, calibrated numerical models are used to examine limestone pillar stability in these conditions. Also, the critical interburden thickness required to minimize the interaction between mining levels is explored. The model results show that there is interaction between numerous factors that control the stability of stone pillars in multiple-level conditions. The highest degree of local pillar instability occurs when pillar overlap ranges between 10 and 70 percent. The highest degree of stability occurs when pillars are stacked.

Jan 1, 2023

By S. Dereski, G. Chancellor

"INTRODUCTION Barrick Goldstrike underground mine is located in Northern Nevada on the Carlin trend. The underground mine produces approximately 1.5 to 1.8 million tons a year and approximately 400,000 ounces of gold a year. The mine is comprised of two main mining methods, underhand drift and fill and long hole stopeing. The mass blast project stated in 2012 as Value in Use project between Barrick, Southwest Energy and Orica, the goal of this project is to be able to blast an entire drilled stope in one blasting event instead of taking multiple blasts. This will improve productivity by eliminating intermediate blasts, reducing additional blast time, eliminate drill hole cleaning due to the previous blast. Project implantation started in the fourth quarter of 2013 and mass blasting has been common practice throughout all of 2014. STOPPING PRACTICE AT GOLDSTRIKE BEFORE MASS BLAST PROJECT The production from the Goldstrike mine is approximately 70% from stopes. The timely completion of all stoping blocks is imperative to maintaining the plan, delays in the execution of any particular block can have detrimental ripple down effects as neighbouring stoping blocks become delayed. Before the implementation of this project the standard practice for Goldstrike was to: 1. Drill the entire stope 2. Blast a bottom shot, normally between 10 feet and 20 feet off the bottom of the slot rings. This would be mucked out before the next shot 3. Blast a pull through shot, this included the raise and one or two production rings. Again mucking this out before the next shot 4. Blast production rings, one or two more blasts depending on stope size. In most cases between each of these blasts the holes in the other rings of the stope would have to be cleaned. This meant either cleaning manually using air and water, or mechanically cleaning with a bench drill. In many cases this resulted in delays in completing the stoping block."

Jan 1, 2015

By R. Kealey, D. Huo, Q. Zhang, Y. A. Sari

Greenhouse gas (GHG) emissions from primary mineral and metal production account for ~10% of global GHG emissions. One of the main sources of GHG emissions in mining operations is fuel consumption by haul trucks. Given their size and carrying capacity, the fuel consumption of haul trucks can approach 250 liters per hour. An average of 30% of the idle time of the trucks is spent while waiting in the queue. Inefficient truck dispatch planning can waste resources, cause dilution and elevate GHG emissions. In this research, a machine learning based truck dispatch approach was developed to dynamically route the haul trucks based on the loaded material, the road traffic, the estimated wait time, and the maintenance needs of the trucks. The GHG reduction potential of this smart fleet management approach was estimated by calculating and comparing the related carbon emissions versus scenarios using traditional fleet allocation approaches. Results suggest that this dynamic fleet allocation approach can significantly reduce GHG emissions at mineral production sites by optimizing waiting times and the overall distance travelled while achieving the same production levels.

Mar 2, 2022

By R. Sandrik

Northwestern Resources Co. (NWR) was established in 1972 as a wholly-owned subsidiary of Western Energy Company of Butte, Montana, to acquire, explore, develop, and produce energy resources outside the state of Montana. Western Energy is a coal mining company with successful operations in Montana and Wyoming. In 1974, NWR acquired its first lignite lease in Texas. NWR eventually acquired a large leasehold in central Texas, which was identified as having a high potential for future production. In 1979. NWR contracted to supply lignite to Utility Fuels, Inc. (UFI), a fuel affiliate of Houston Lighting and Power Company (HL&P). This project, together with leases held by UFI, became the Jewett Mine. Lignite from the Jewett Mine is used as fuel at the adjacent HL&P Limestone Electric Generating Station, at an annual rate of approximately 7.3 Gkg (eight (8) million tons) per year.

Jan 1, 1991

By M. Akser

Ilmenite, rutile, and zircon deposits of commercial importance have not been reported to-date from Turkey. However, information from recent reconnaissance activities indicates the possibility of an economically viable heavy-mineral deposit along the Black Sea coast of Turkey in the vicinity of Ormanli, northwest of Istanbul. Consequently beach and sand dune samples were collected from that area for additional analysis. Laboratory methodologies, designed to simulate standard industrial heavy-mineral plant practices, were used to analyze and evaluate the samples. Based on the analyses, and current market needs, none of the deposits in the Ormanli area qualify as a commercial heavy-mineral deposit.

Jan 1, 1995

By A. W. Khair

In 1985, an extensive longwall mining research project was initiated by the West Virginia University Research Center entitled "An Improved Longwall Mining Technique" with the purpose of providing operational guidelines for the mining industry to enable efficient operation of its existing and projected longwall installations. One task involved in this extensive research project was monitoring ground movements due to longwall mining and evaluating their impact on surface and subsurface structures. This paper presents an analysis of the effects of topography on quasi-static and dynamic ground movements and the severity of damage inflicted on surface structures. The site was chosen for the study with an attempt to obtain a representative account of the topography experienced in the Northern Appalachian region, and more importantly to contain a substantial number of varying topographical features i.e., mountains, hillsides, valleys, and flat bottom land. The study was made possible by typical subsidence monitoring technqiues, however subsidence monuments were surveyed on a frequent basis, intermittently during face advancement. Ground movements were investigated under both quasi-static and dynamic conditions. This provided insight into the propagation of subsidence and the dynamic affects it has upon surface structures.

Jan 1, 1987

By W. A. Haley

Wheel loaders were first introduced shortly after World War II as small machines designed for handling loose materials in various industrial and processing applications. It was not until the early 1950?s, however, that machine size permitted widespread loading of loose or stockpiled material into on-highway type trucks. An ever increasing number of machines continue to be used for this purpose today. In fact, it is by far the major use for wheel loaders in mining and quarrying. Many of these loaders were working at mines or quarries handling in-process or finished material and some were doing shovel clean-up. It was quite natural then, when the primary pit loading shovel was down, to attempt to maintain some production by replacing it temporarily with the wheel loaders. Most of these attempts were not very successful, however, until the really large wheel loaders, 4- to 6-yd. size were introduced in the early 1960's. Since that time these machines have proven they can be productive and economical primary pit loading tools, a job that was once the exclusive domain of the power shovel. To be competitive with the shovel however, conditions must exist or be made to exist, that will be favorable for the wheel loader.

Jan 1, 1967

By Arshad Ali, Mudassar Khan, Waqas Ahmad, Nisar Muhammad, Muhammad Salman

Talc is an important industrial commodity due to its wide-ranging intrinsic properties; however, the presence of iron oxide hinders its industrial utilization. Herein, we report the purification of Pakistani talc through acid leaching assisted by chlorination techniques. Among various acids (i.e., HF, HCl, H2SO4, HNO3, H3PO4, Aqua Regia, H3BO3, and CH3COOH), HF was the most effectual, removing up to 67% of iron oxide at optimized conditions of temperature, 90–95 °C; time, 120 min; HF concentration of 5%; and at a pH of 1. In the second step, chlorination of the talc sample was performed separately by both wet chlorination and dry chlorination. Wet chlorination was carried out using KMnO4 and HCl in slurry phase which shown about 52% removal of iron oxide, whereas dry chlorination with CaCl2 at high temperature attained about 48% removal of iron oxide from talc sample. Further, the wet chlorination of HF leached samples was also performed under optimized conditions which showed up to 87% iron oxide removal. The original and treated talc samples were characterized by EDX and XRD analysis to monitor the changes in the elemental and mineralogical composition of the talc. It can be concluded that HF leaching followed by wet chlorination is an effective method for the upgradation of low-grade Pakistani talc ores.

Aug 9, 2021

By R. L. Godfrey

The Custom Coals advanced coal cleaning plant will be designed with a unique blending of existing and new processes to produce two types of compliance coals: Carefree Coal? and Self-Scrubbing Coal?. Carefree Coal will be produced by cleaning the coal in a proprietary dense media cyclone circuit utilizing fine magnetite to remove up to 90 percent of the pyritic sulfur and correspondingly greatly reduce the ash. While may utilities can achieve full S02 reduction compliance with Carefree Coal, others face higher sulfur reduction requirements due to the higher sulfur content of their existing fuel supplies. For these circumstances, a patented Self-Scrubbing Coal will be produced by taking Carefree Coal and pelletizing limestone-based additives with the finest fraction of the clean coal. These technologies will enable over 150 billion tons of non-compliance U.S. coal reserves to meet compliance requirements.

Jan 1, 1995

By Bobby Michael (Mike) Roberts, G. M. (Mike) Bernard, Ronald R. Kelly

This paper describes Cananea's successful implementation of the world's first mobile high angle conveyor (MHAC™) to achieve multiple-lift stacking of their primary crushed (2,500 mtph) low-grade ore. The mobile high angle conveyor answered Cananea's needs to stack a second lift, 30-meter high, on their Quebalix I pad. The mobile high angle conveyor is a custom unit that was designed by Terra Nova Technologies (TNT) in conjunction with Continental Conveyor and Equipment Company (CCE's 100th HAC). The stacking system expansion project also includes a rail mounted tripper on the existing overland conveyor and a custom designed "corridor conveyor" to build the corridor for the upper mobile HAC tracks and tail of the existing mobile stacking conveyor. Mexicana de Cananea, part of Grupo Mexico, is a large copper producer in Sonora Mexico and has been in operation continuously for over 100 years.

Jan 1, 2002

Because the Environmental Protection Agency has identified methane as a greenhouse gas, the importance of de gasification through gob wells has become more critical. It has been observed that the degree of methane emission is closely related to the geomechanical characteristics of coal bearing strata, roof, floor, and surrounding coal seams. Monthly production data from 250 gob wells were collected from the Warrior Basin in Alabama, and many interesting correlations were observed between methane production with longwall face width, face advancement rate, number of gob wells in a panel, and geologic columns. Extensive finite element analyses were performed to estimate the characteristics of the emission zone in an attempt to corroborate these findings. This paper describes an investigation for developing correlations between the geomechanical behavior of the methane emission zone with methane production.

Jan 1, 1996

By John J. Stetler

The Companhia Vale do Rio Doce in Brazil operates one of the most extensive systems in the world for the mining, transportation, processing, pelletizing and shipping of high grade hematite iron ore and pellets. Current shipping of unbeneficiated, sized, high grade ore from its ports at Tubarão and Vitória is now at the rate of 17,500,000 metric tons annually. An increase in this annual rate is now under study. Using the technology and facilities of Lurgi (1) and Arthur G. McKee company CVRD undertook a program to process and pelletize two types of fines - "Blue Dust" and ?Itabira Fines?. Blue Dust is a high grade fine ore which was bypassed while mining the direct shipping ores and which, also, exists as a very large ore body called the Conceição Mine. Itabira Fines is a lower grade of fine ore which is comprised of in-situ fines and, also fines which are generated in sizing the direct shipping ores for a rigid specification market.

Jan 1, 1970