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By Dianne C. Marozas

The U.S. Bureau of Mines is conducting research to evaluate the potential for developing an in situ leach mining process that will selectively extract manganese from oxide ores, leaving gangue relatively undisturbed. To accomplish this, a geochemical approach, based on deposit-specific information such as mineralogy and geology, is used to constrain the operating parameters of the system. Among the studies being conducted are (1) leaching experiments to define reaction mechanisms and kinetics, (2) detailed petrologic characterization at the microscopic scale to assess Mn distribution and leaching efficiencies, (3) deposit characterization and evaluation, and (4) development of potential Mn recovery schemes. Data from these studies are being used to develop engineering design information for an in situ mining process. Specific details of the Bureau's research project are discussed, including results obtained to date.

Jan 1, 1991

By MUSTAFA ERKAYAOGLU, ENVER YILMAZ

Coal is still a part of energy generation worldwide and has a significant role in the sustainable development of countries. The amount of shallow coal deposits is getting scarce, making efficient underground mining operations crucial for both local and global economies. In underground mining operations, longwall mining is a commonly utilized method to extract deep coal deposits. One of the leading engineering goals in longwall mining is increasing the efficiency of the system by investigating the effects of operational factors on equipment. This paper investigates the shearer performance for a longwall top coal caving operation by discrete event simulation that includes modeling the double-drum shearer, belt conveyors, stage loader, and armored face conveyors (AFC) to evaluate system performance by considering the amount of daily coal production of the shearer. As a result, the most influential factor on mine production is determined and a data-based framework is developed. This study suggests a framework for data collection, data analysis, and the interpretation of the operational data to evaluate the primary production unit’s performance. The models developed for the face coal extraction operations in a longwall top coal caving (LTCC) mine have a bi-directional cutting system and can be implemented in other operations readily.

Jul 2, 2021

By P. Mills

The four top barite-producing countries in the world are China, India, Morocco and the United States. China is currently the largest exporter of barite followed by India. More than 95 percent of the barite mined today is used by the petroleum industry as driller’s mud. The rest is used in the industrial market and the medical field. Most of the barite mined in the United States is in Nevada. This year, mining activity has increased due to an increase in oil exploration/development. This was caused by an increase in the crude oil prices.

Jan 1, 2005

By L. Mead

Dimension stone is a natural stone (granite, marble, limestone, sandstone and slate) that can be quarried, cut and shaped to conform to acceptable industry standards for size, consistency and durability. There are numerous outlets for the finished product in exterior and interior architectural and design applications. A continued growth market is with residential usage— particularly in new, upscale construction. This has become a competitive market between domestic producers and lower cost imported products. These imported products have become available at many of the building supply retail outlets and have increased the use of stone in residential construction and renovation. The traditional architectural application of dimension stone is tied to commercial and institutional building construction trends and market. There has been a noticeable increased usage of stone in the Sun Belt. This stone is usually supplied by local fabricating shops. It is used in the exterior and interior of shopping malls. This market generally uses local stone sources. It has increased the demand for sandstone, limestone and quartzite in this region of the country.

Jan 1, 2005

By C. Frenzel

Tunnel boring machines (TBM) utilize disc cutters as the primary means for excavating hard rock. Depending on rock excavatability and rock abrasivity disc cutters can exhibit significant wear. A detailed analysis has been carried out to characterize failure modes and wear patterns of disc cutters. The relationship between rock properties, op-eration of the TBM, and failure modes of cutting tools is clearly high-lighted. On that basis a prediction tool for disc cutter consumption has been developed that allows to estimate not only gross cutter life, but accounts for cutterhead design, premature cutter changes, and disc cutter repair costs.

Jan 1, 2011

By Harvey Parker

This is part two of an article on the prominent role that the United States and its industry leaders have played on the International Tunnelling and Underground Space Association (ITA), which represents the underground construction and underground space industries worldwide. The U.S. is officially represented in ITA by UCA of SME. (Part one is in T&UC, June 2007, pp 39-42) Tunnel advances in 1960s and 1970s The 1960s and 1970s were active and productive times for the U.S. tunneling industry. During that time, federal programs, sponsored by the Federal Railroad Administration (FRA), the Office of High Speed Ground Transportation (OHSGT) and the Advanced Research Projects Administration (ARPA), stimulated tunnel research and development. Also, the American Society of Civil Engineers (ASCE) and SME collaborated to create the Underground Construction Research Council (UCRC) and the Rapid Excavation and Tunneling Conference (RETC) series.

Jan 1, 2007

By J. Leinart

As is readily apparent, the reliability of the early-stage costs estimated for any mining project are critical to the viability of that project. An estimate too high might leave a potentially profitable deposit undeveloped or worse yet, available to a competitor. One too low might waste investment dollars in a project not yet economically ripe. There are two aspects critical to any estimate: 1. The cost data used to represent the values of the wages, salaries, supplies, and equipment. 2. The design used to determine the engineering parameters upon which the above estimated values are based. Given that all of the information contained in Mining Cost Service is provided by suppliers, equipment manufacturers and mine operators, one wonders why there is any question as to the reliability of cost estimates developed using this information. Given that it is all actual (as opposed to statistically derived) data, where do the problems with estimate reliability lie and what is the impact of the data on that reliability? The following presents a series of analyses designed to assess the reliability of the cost estimating process. Both the actual cost data and the engineering parameters upon which they are based are examined in an attempt to quantify and understand the importance of each. While several sources of cost information are available (Means, Richardson, Primedia?s Equipment Watch, and individual suppliers and manufacturers), the following rely solely on data contained in InfoMine USA, Inc?s, Mining Cost Service and in its Sherpa Mine Cost Estimating Software.

Feb 27, 2013

By Ramon LaRusso, Frank Wheby, Richard Acker

Field investigations and office studies were used to develop criteria and cost parameters related to the geologic aspects of the proposed project. These results were employed in optimization of layouts and comparison of alternative schemes, leading to selection of the recommended program. Study of project features included the development of subsurface shafts, tunnels, and mined storage areas, and the utilization of existing surface quarries. These project features were proposed for construction within the bedrock units underlying Chicago. Principal geologic considerations included bedrock structure, stratigraphic sequence of units, rock competence and uniformity, and requirements for aquifer protection. All geologic factors were interrelated with other project considerations such as surface hydrology, hydraulics, and urban setting. Data for analyses was acquired through an exploration program conducted intermittently between 1967 and 1971, in addition to that already available through numerous explorations and well constructions in the project area. The exploration program included seismic surveying, core drilling, geophysical borehole logging, and water pressure testing of boreholes, and water well drilling and testing. Extensive laboratory tests were conducted on core samples. The data formed the basis of studies enabling the formulation of preliminary design and siting criteria resulting in construction cost evaluation.

Jan 1, 1997

By R. S. Conti, M. R. Krump, C. P. Lazzara Ph. D., R. L. Derick, L. L. Chasko

A mine fire is one of the most challenging safety issues facing a mine operator and can occur at any location underground. The National Institute for Occupational Safety and Health (NIOSH) and the Twentymile Coal Mine, CO, conducted in-mine experiments to determine the capability of high-expansion foam for addressing underground fires. The tests were conducted in sloping entries with high-capacity diesel-powered foam generators. The following results were observed: a well-designed, maintained and properly operated high-expansion foam generator can propagate a foam plug hundreds of feet in steep upward-sloping (20%) multiple entries against a ventilation pressure; stoppings and partitions designed to contain the foam plug in upward-sloping entries must be substantially constructed; and the predicted quantity of foam concentrate can be significantly less than the actual amount used, due to foam losses, such as bubble breakage on dry surfaces. This paper describes the production of high-expansion firefighting foam and discusses the in-mine experimental tests and results.

Jan 1, 2010

By A. Karami

It is well established that an ordered sequencing of charge initiations in a blast pattern is an important design consideration that affects blasting performance. Delay times must be chosen such that damage to the rock mass is controlled. The accuracy of delay detonators is also of major concern. A large scatter could lead to an incorrect blast sequencing that would lead to damage to the rock mass causing increased over-break, degraded fragmentation, increased fly-rock and poor vibration control. In this study, the effect of using accurate delay detonators on the explosive energy generated is investigated. For this purpose, power spectral density of the blast vibration for delayed shots are calculated and compared with the case where holes are shot at the same time (no delay). At the end the results are presented and discussed.

Jan 1, 2000

By Kazuya Naito, Nobuyuki Okamoto, Natsumi Kamiya

JOGMEC (Japan Oil, Gas and Metals National Corporation) became the first entity to sign an exploration contract for Cobalt-rich Ferromanganese Crusts (Crusts) with the ISA (the International Seabed Authority). The contract was signed on 27 January 2014, and 15 years exclusive rights for exploration activities had started in the contracted area, located in the North-Western Pacific Ocean. JOGMEC had already conducted basic scientific surveys around the contracted area from 1987 to 2012. Activities by JOGMEC that will be undertaken during the first 5 years of the contract include examination of geological and acoustic surveys, environmental baselines surveys, and undertaking basic studies of R&D in mining, processing, and smelting technologies. Geological surveys will include analysis of rock core samples, using BMS (Benthic Multi-coring System). Deep-towed TV Camera will be used to estimate the distribution of crusts deposit and to get basic environmental data of deep-sea megabenthos. Water sampling, marine sediment sampling, and installation of mooring systems on the seafloor will also be conducted as a part of environmental surveys.

Sep 1, 2014

Newmont has been producing gold from the Carlin Trend for over 45 years. Naturally the focus, scale and complexity of the operations have changed considerably over this time. Newmont discovered and developed the Carlin Main ore body which is located about 32 km (20 miles) north of Carlin Nevada. The property was developed as a one mine one gold mill treatment plant operation which produced about 6,200 kg (200,000 Troy ounces) of dorè gold bars per year. The initial mine, mill and gold refining facilities were relatively small in comparison to today?s standards. The milling circuit used the Merrill-Crowe zinc precipitation process to recover dissolved gold and prepare a concentrated precious metal ?precipitate? to be melted into a dorè bar for sale.

Jan 1, 2012

By S. R. Dismukes

Mining is likely to be targeted by The United States Environmental Protection Agency (“EPA”) as one of its key enforcement targets for fiscal year 2002-2003. Identifying the mining industry as an enforcement target, coupled with an increase in enforcement activity in recent years, places each mining operation at increased risk of receiving enforcement attention. A properly developed and implemented Environmental Management System (“EMS”) tailored for your operation is invaluable in reducing the risk of incurring liability for non-compliance. At the heart of an effective EMS is an audit program that checks the company’s compliance with environmental requirements. In addition, audit privilege (in select states), voluntary self-disclosure, and the attorney-client privilege serve as very effective tools for managing those liabilities that may arise during auditing a well-developed program. Of course, these latter tools are effective only if the auditing program is properly structured and properly managed. EPA and some states also provide varying degrees of immunity for environmental violations that are voluntarily disclosed in writing by the company. However, self-disclosure laws and policies typically prescribe stringent requirements for parties seeking to take advantage of them. For example: U.S. EPA has recently extended the time period in which to provide full written self-disclosure to 21 days. However, U.S. EPA’s revised Self-Disclosure guidance also addresses when a company obtains knowledge of a violation for purposes of triggering the 21-day clock and specifically extends the knowledge requirement to include the company’s agents and consultants. This expansion increases the difficulty companies may have in clearly defining and managing when they obtained knowledge. This difficulty increases the importance of managing factual development and the strategic use of other

Jan 1, 2001

By K. Vatterrodt

Thallium is not significantly removed from mining influenced water (MIW) through conventional treatment in hydroxide precipitation plants. We experimentally investigated modifications to hydroxide precipitation schemes to concurrently remove thallium. Our goal was to determine cost effective and efficient hydroxide precipitation process modifications for thallium removal. Strategies for removal targeted multiple mechanisms including sorption, co-precipitation and/or oxidation of monovalent thallium. Modifications were tested in batch and included oxidant evaluation and the role of manganese. Removal of thallium was enhanced by the addition of permanganate as well as oxygen by aeration. In addition, contact with retained solids and the initial manganese concentration played an important role in the extent of thallium removal observed. This paper reports on our findings and discusses the implications in the removal of thallium with minor modifications to the hydroxide precipitation process.

Feb 27, 2013

By M. Zuckerberg, E. Mader, R. Pasyar

We describe a new software product designed for the net present value optimization of multi-open-pit blended ore operations in which it is desired and/or necessary to dump some or all of the waste rock produced in the course of operations back into the voids created in the process of ore extraction. The software product simultaneously decides over the entire life-of-mine which material to mine in which year, once mined what to do with it, and where to put that material which it has decided to waste, all subject to annual blend and capacity constraints.

Jan 1, 2007

By A. S. Haugh

OHSAS 18001 is a series of international standards for occupational health and safety management. It is comprised of two parts, 18001 and 180029. OHSAS 18001 was formulated by international certifying bodies and is based on BS8800 and was first published in 19996,11. OHSAS 18001 was developed to be compatible with ISO 9001 and ISO 14001 in order to facilitate integration of quality, environment, and occupational health and safety management systems5. It is a voluntary standard and the overall aim of OHSAS 18001 is to enable organizations to control their occupational health and safety (OH&S) risks and improve overall health and safety performance5. OHSAS 18001 is widely accepted in the UK, Europe, and Asia, is gaining momentum in North and South America, and it was used as the basis and conforms to the requirements of ANSI/AIHA Z.10-2005: American National Standard for Occupational Health and Safety Management Systems. It defines a set of requirements for an occupational health and safety management system suitable for any kind and size of organization4. Businesses of all sizes are developing and implementing occupational health and safety management systems (OHSMS) that are in compliance with the OHSAS 18001 standard.

Jan 1, 2012

By M. L. Chapman

When originally accepting the assignment, the Client had described the property as vacant land. A prior appraisal was later discovered and revealed that the property included a mineral rights appraisal. Further research disclosed an old dispute with a court ruling based on testimony by AIMA-certified experts. The present appraisal was therefore based on data from findings of the court with a fresh look at discount rate, absorption period, and residual land value. Fortuitously, the property subsequently sold on the market, while meeting all criteria for Fair Market Value. This provided insight into a market-based discount rate. Also, the absorption period could be adjusted in accordance with the current market conditions. The residual land value was minimal (based on comparable sales and projecting trends in market) as the property was affected by a flood zone and the surrounding development was sparse. PROPERTY HISTORY: A GREAT INVESTMENT Briefly, the subject property is located in the floodplain region of the San Jacinto River, a short river in southeastern Texas that flows into Galveston Bay, filled with sand and gravel. This location is on the north side of Houston, north of Beltway 8 on the east side of I-59.

Jan 1, 2012

By Larissa Koroznikova, Steve Durkin, Patrick Bouwmeester, Michael Tuck

In currently used mining methods, blasting techniques often causes dilution of valuable ore and results in costly processing requirements. In the context of narrow vein mining of thin and highly concentrated orebodies there is a need of a mining method that can reduce dilution in order to remain economically viable. This research project explored the viability of a new mining technology, thermal fragmentation, in narrow vein mining. Thermal fragmentation technology uses a flame jet to produce extreme heat that spalls the surrounding rock to a strategically located drill hole, as an alternative to traditional blasting. This paper creates a net present value (NPV) model of a mining method using thermal fragmentation, as well as for an existing method used for narrow vein mining; comparisons and evaluations were made regarding the feasibility of the new technology. It was found that while overall costs for thermal fragmentation were relatively high, reductions in wages, haulage and processing costs, as well as increased productivity and ore recovery, meant that the new method would improve the financial performance of any operation. These results identify that there is an opportunity to introduce the thermal fragmentation technology to narrow vein mines within Australia, in order to lower costs and increase profit.

By J. Hebert, J. Donnelli, J. Sedey

Installation of a Load Commutated Inverter (LCI) provides an economical method for conversion of a Fixed Speed Semi-Autogenous Grinding Mill into one with variable speed, qualities. Though capital intensive, the conversion appears to be one of the most cost-effective methods to gain the advantage of critical speed variations for variable ore characteristics. Expected advantages from the installation of LCI drives at the Goldstrike Mine were decreased liner wear, decreased media consumption and additional grind for increased production rates. These issues as well as construction, economics and performance will be discussed in the presentation. The utilization of the existing equipment came to play an integral part of the study and economic justification of the overall project.

Jan 1, 1999

By Reed Thorne

To many people, rescue from elevated, sometimes vertical, locations brings about thoughts of heroism mixed with brawn and self-sacrifice. Images are conjured of cliff rescues where the technical effort is hanging from a few seemingly small nylon ropes hundreds of feet above the ground. Such is the vertical realm of technical rope rescue. This is a technical field in which the author serves professionally as battalion chief of (rope) operations for a northern Arizona fire district, and as a private sector instructor to mines in the United States and Canada.

Jan 1, 1996