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The authors provide a discussion of the paper, ?Coal workers? pneumoconiosis prevalence disparity between australia and the united States,? a peer-reviewed paper that appeared in the technical papers section of the July 2012 issue of Mining Engineering magazine. The original authors, G.J. Joy (gjoy@cdc.gov), J.F. Colinet (jcolinet@cdc.gov) and D.D. Landen (dlanden@cdc.gov), respond.

Jan 1, 2013

THE QUARTETTE Mine near Searchlight, NV, a mine that first operated in the 1890s, could begin processing ore again by September. Jetco Enterprises Inc. plans to work through the tailings and ore close to the surface followed by plans for an openpit mine. It is one of at least three new mining efforts in the region, the Associated Press reported. Another is north of Searchlight, with yet another across the Colorado River in Arizona, east of Bullhead City. Gold mining is rare in southern Nevada. The area generally lacks the rock type that contains gold deposits. Restrictions on federal wilderness areas and protections for the desert tortoise also play a role. Gold veins in the region are generally small and erratic in length and height, Bill Durbin, a geologist and chief of southern Nevada operations for the Nevada Division of Minerals told the Associated Press. L.R. Tad Tinnell, president of Jetco Enterprises, has long eyed the mine. From 1993 to 1995, he explored and drilled on the property, which was still owned by Searchlight Mercantile.

Sep 1, 2013

By G. Jalkanen

Parameter estimation of the inverse distance estimation algorithm is presented. The objective function to be minimized is a sum of squared cross validation errors. The unknowns to be estimated are the exponent of the inverse distance estimator and anisotropic angles and ratios that are used in determining the distances in the algorithm. Examples are presented for both two and three dimensions data sets.

Jan 1, 2009

By S. E. Younis

The mining industry is currently looking to better understand, anticipate, and be able to mitigate business and operational risks in order to deliver the rewards of risk taking, and to minimize the frequency and impact of risk on the downside. Assessing risk works from the premise that the identification and management of existing risks can be very challenging, especially when threats are not easy to detect, the likelihood of occurrence is difficult to gauge, and/or the consequences are uncertain. Some approach this as a ?check the box? task, even though fire and safety incidents continue to occur and investigations often find the hazard analyses did not properly identify the cause or consequence. You cannot engineer protective designs and safeguards for causes and consequences that have not been identified appropriately. For the mining industry, risk management is an important tool for making critical decisions and, in some cases, meeting regulatory requirements. Providing high-quality documentation that meets both regulatory and corporate requirements is critical for maintaining safe, uninterrupted mining operations. Risk management is a five-part process: 1. Identify the hazards and their causes, 2. Determine the hazard consequences, 3. Calculate the frequency of occurrence, 4. Quantify the risk associated with the system, process, or procedure, and 5. Provide feasible solutions for the risks

Jan 1, 2012

By M. Michael, A. Felber

"Mining activities, especially underground mining operations, create great demands on utilized haulage means which cover a variety of different horizontal and vertical distances. In the course of the continuous optimization of the haulage process, the application of textile machine elements, in particular synthetic fiber ropes, offers new opportunities. Therefore the current level of knowledge needs to be improved based on extensive analyses. For the estimation of the scope of these analyses, different fields of application and occurring environmental influences which have an impact on synthetic fiber ropes during their use in underground mining have to be evaluated. The Chair Underground Mining Methods of the TU Bergakademie Freiberg works on a scientific project concerning the use of synthetic fiber ropes in underground mining operations. This paper focuses on the potential application of synthetic fiber ropes in haulage systems in underground mining and exposes critical influences as an outcome of the working environment. These first investigations are the basis for the development of an appropriate experimental series. SYNTHETIC FIBER ROPES FOR UNDERGROUND MINING OPERATIONS The main idea is to optimize underground haulage means to develop even more economic systems. The new and lightweight design of single machine elements seems to be the first step to accomplish this goal. An example is the lightweight design of shaft hoisting ropes. The commonly used steel wire ropes are very heavy and are endangered to snap due to their own weight when reaching a distinguishing length. Thus they may not or only conditionally be used for deep mining operations utilizing shaft haulage. Ropes made of high-tech synthetic fibers weigh only an eighth of steel wire ropes while displaying the same tensile strength. This relation is shown in Figure 1, based on the comparison of fiber strength and density. This could offer new opportunities for deep mining operations, which are anticipated by many mining companies. /1/"

Jan 1, 2015

By T. Pool

Introduction After two decades of contraction and consolidation, the uranium industry has seen a recent major expansion. Rapidly increasing uranium prices and the ability to raise speculative capital in share markets worldwide have brought over 300 new participant companies into the uranium industry: “juniors” as they are known. These companies participated in a global land rush for known deposits as well as for prospective land positions in order to secure a “piece of the action” for their respective portfolios. Mostly publicly-traded companies, these “juniors” have captured the attention of world’s investing public with spectacular gains; as much as 1,000s of percent in less than four years. The initial phase is over, however, and these companies must now prove that they can be successful in exploration or production.

Jan 1, 2007

By R. Graeme, J. Komadina

Gold Fields acquired an option to purchase the Cerro Corona Project, located in Hualgayoc, Cajamarca Department, Perú, in December 2003. In January 2006, the option was taken up and the transaction closed. During the intervening months, Project development occurred against the backdrop of a Presidential election, increasing national social activism and environmental regulation, rapidly escalating operating and capital costs, as well as unprecedented demand for engineering and technical skills. Project “Lessons Learned” are outlined and discussed in the context of an evolving strategy.

Jan 1, 2007

By R. C. Milici

The primary factors that determine the marketability of coal from various supply centers in the U.S. are coal quality and supply; i.e. low sulfur, moderate- to high- Btu coals have large market areas when compared to less expensive but poorer quality coals. Price is the major factor in the competitive marketing of similar coal products. Good quality, (moderate- to high- Btu, low sulfur) coals from the Powder River and central Appalachian basins are marketed over large areas of the country, and central Appalachian coal is widely distributed in foreign markets, primarily as coking coal. In contrast, poorer quality bituminous coal (low calorific value and/or high sulfur) from the Illinois Basin, northern Appalachian Basin, and lignite from the Gulf Coast is marketed in or near the States in which it was mined even though the price at the mines may be lower than mine prices for central Appalachian coal. Widespread distribution of sub-bituminous Powder River Basin coal is enhanced by its exceptionally low mining costs, which offsets transportation costs to distant markets.

Jan 1, 2001

By B. Cousins

Flotation reagents are critical to the optimum performance of flotation circuits. How a flotation reagent performs within the first few cells of a flotation train is a key indicator of how well it will perform throughout the entire circuit. A method to compare reagent performance was recently developed by Ashland Water Technologies. The procedure involves collecting a timed sample of concentrate from each cell and then measuring the volume of the settled solids. An estimate of the percentage of concentrate collected from each cell can then be mathematically determined, providing an understanding of the recovery changes in each cell. Data from trials at a coal flotation circuit are used to demonstrate the method's validity.

Feb 27, 2013

By A. G. Taylor

High value materials, such as gold, platinum and other precious metals are subject to loss through unauthorized removal from mines, smelters, refiners, and other places where such materials are processed. A study published in 20011 determined that between 1994 and 1998 an average of 603 kilograms of gold per year was stolen from South African miners and subsequently recovered. This does not include the gold that was stolen but not recovered. At 2011 prices, 603 kilograms of gold would be worth approximately $33 million. Mine security personnel believe that the unrecovered stolen gold far exceeds what is recovered2. Traditionally, metal detectors have been used to screen personnel leaving secure areas to discourage such unauthorized removal. However, with the current near-record prices of gold, platinum, and other precious metals, it has become worthwhile for people exiting a facility to walk out with quantities of product that are too small for ordinary metal detectors to register, resulting in substantial financial losses.

Jan 1, 2012

By CHONG WEI, TATYANA KATSAGA, DEREK APEL

This study provides an effective determination process of the interface microstructural parameters in the numerical modelling of the mechanical interaction between two different geomaterials involved with frictional-bonded interfaces, such as the interaction between backfill columns and the surrounding rocks, or the soil-structure interaction, by using the coupled finite-difference and discrete-element (FD-DE) method. Three-dimensional numerical direct shear tests were conducted on the coupled FD-DE model of the combined rock-cemented rockfill (R-CRF) specimens with the frictional-bonded interface. With the microstructural parameters determined, the macro-mechanical properties of the interface of the coupled model were calibrated to well fit with the theoretical values of the combined specimen under the direct shear condition assumed according to the Mohr–Coulomb strength criterion. Evident elastoplastic shear behaviour was observed on the interfaces, and excellent agreement was attained between the shapes of the theoretical and simulated shear stress-displacement curves of the coupled models at different servo-controlled normal stresses. Particulate-scale force chains inside the DE model of the CRF specimen were highly consistent with the force contour on the FD model of the rock specimen, demonstrating the shear stress evolution of the coupled model at different shear displacements. Parametric studies verified the effects of the deformation properties of the interface parallel bonds on the shape of shear stress-displacement curves of the coupled models. The test results validated the feasibility and rationality of the coupled FD-DE method for modelling the combined specimens with frictional-bonded interfaces or joints. Furthermore, this study provides valuable numerical modelling experience for investigating the shear behaviour at the interface between cemented backfill columns and surrounding walls by using the coupled FD-DE method.

Nov 2, 2021

By William Connell

NFPA 502, Standard for Road Tunnels, Bridges and Other Limited Access Highways establishes minimum fire protection and fire life safety requirements for road tunnels, bridges and other roadways where access by emergency responders is physically limited. The 2008 edition of NFPA 502 represents the Technical Committee?s consensus of current best practice for fire protection and life safety requirements for road tunnels, bridges and similarly limited access highways. Research of national and international test programs, design guidelines and regulating standards was per-formed and considered in an effort to establish a singular, comprehensive document representing a recognized base threshold of fire safety in these type facilities. This paper provides an overview of the more significant revisions including the application of fixed fire suppression systems, guidance on tenable environment, protection of structure and dangerous goods transport.

Jan 1, 2008

Ion exchange (IX) has been in use for a long time, references to IX are made in The Bible, Exodus Chapter 15 vs. 22-25 ?and the waters were made sweet?.1, 2 Aristotle noted a reduction in the salt content of water when passed through certain types of sand, a phenomena probably associated with ion exchange characteristics of zeolites. Some major milestones in IX development include; ? ~ 1400 BC Moses ? ~ 330 BC Aristotle ? 1850 the discovery of the IX process3 ? 1909 Gans proposed zeolites for gold recovery ? 1935 sulfonated coals used for water softening ? 1939 copper recovery from Rayon Production ? 1940 The Rare Earth Project at Ames ? 1952 first South African U IX mine at West Rand (first SX of U using amines 1957) ? 1954 first U IX in USA at Shiprock Mine N.M. USA. ? Late 1950?s U IX over 50 fixed bed systems installed in North America ? 1950?s-1960?s FSU introduce U IX both fixed bed and RIP ? 1968 Gold IX (RIP) Muruntau Uzbekistan (CIL wasn?t commercialized until 1973) ? Mid 1970?s FSU & USA independently develop ISL combined with IX for U recovery ? 1978 Chinese Tungsten IX commercial Plant ? 1984 Uranium extraction from seawater ? 2004 Recovery of Gallium using hydroxyamic acid ligands ? Current ? Commercialization of IX for recovery of gold thiosulfate. Ion exchangers can be naturally occurring or synthetic; the majority of ion exchange materials in use today are synthetic resins based upon organic polymers such as polystyrene or methacrylate. Into more modern times the use of ion exchange for metal recovery was first proposed for the recovery of gold using zeolites in 1909.4 In 1939 copper was being recovered from the manufacturing of Rayon using ion exchange5 a development that continued applicability through to current times in the production/recovery of copper and nickel in ammoniacal leach processes. In early 1949 researchers at the Rohm & Haas Company discovered that hexavalent uranium existed as an ionic complex in sulfuric acid leach liquors, and that quaternary ammonium anion exchange resins exhibited a high selectivity for this ionic species6 The first commercial application of this technology went on-stream in October 1952 at the West Rand Consolidated Mines, Ltd operation in South Africa. 7 Ion Exchange has been applied for the recovery and purification of a range of metals;8 ? Uranium, Thorium and transuranic elements ? Rare Earths ? Gold, Silver and platinum group metals (PGM?s) ? Chromium, Copper, Zinc, Nickel, Cobalt ? Refractory Metals; Molybdate, Vanadate, Tungstate, Rhenium Mercury.

Feb 27, 2013

By W. O. Kerr

As in other industries, companies engaged in mining and extraction use and develop intellectual property (?IP?) in the form of new technologies or production processes. The development of IP assets in mining may occur as a byproduct of ongoing operations, or result from investment in dedicated R&D efforts. New technology may lower costs, increase quality of output, and/or increase operational efficiency or safety. Key business questions with respect to any new technology are how best to use IP assets, how to protect them and how to derive value from them. IP assets can provide a competitive advantage to a developing firm that uses the technology to improve its operating results. The developing firm can preclude others from using the technology if it believes that is the best way to exploit the technology?s value. Or, it can be shared with others taking care to ensure rights are maintained, thereby generating royalty income or strategic value through cross licensing or other business relationships. Either way, in order to fully realize the maximum economic benefit, innovators must protect the IP assets and control their dissemination.

Jan 1, 2012

By Frederick J. Murrell

No other region of the world is enjoying the tremendous growth of power use that is currently being experienced in Asia. Fortunately for the coal industry — particularly in Asia — the power plants being planned or under construction are designed to use coal as fuel. This has produced a significant increase in the demand for steam coal that, in turn, has encouraged many in the industry to develop new coal mines. Indonesia is a country that has enjoyed substantial growth in coal production. This developing country has 195 million people who live on the nearly 13,000 islands. It has quickly emerged as the third-largest exporter of steam coal, following only Australia and South Africa. Almost all coal in Indonesia is mined by surface-mining methods.

Jan 1, 1996

By M. Wiber, P. Nicoll

Rio Algom has embarked on a major programme of expansion with the goal of becoming one of the world’s top-performing base-metal mining and metals distribution companies. To assist the company and its operations in achieving its business objectives, we are implementing an environment, health and safety (EHS) management system, built to be compatible with the 14001 model. We recognize that a sustainable development approach for Rio Algom includes outstanding performance in EHS and community responsibility and is essential to earn acceptance within the communities where we operate or wish to locate; raise capital; obtain permits, and operate efficiently. We are committed to triple bottom line accountability, i.e. full consideration of environmental, social and economic concerns in our business decision making.

Jan 1, 2000

By Joy Sandberg

The 1989 mining industry compensation survey done annually by the Denver-based Mountain States Employers Council shows the "average" or "typical" employee in the mining industry is projected to receive an increase of 3.9% to base pay in 1990, compared to a projection of 4.1 % for 1989. According to MSEC, the actual percentage increase to base pay has continued to decline since 1980. A review of pay increases since 1980 shows the highest average increase was 11%, granted in 1981. Since 1981, there has been a steady deceleration through the decade. While 1989 final figures are not available, 1988 numbers might indicate a reversal of this trend. In 1988, the average employee actual increase was 3.8%. That was 0.7% higher than the 3.1% projection. This may be significant as actual increases have been lower than projections since 1982. Chart A shows the pattern of projected vs. actual percent increases in pay since 1980.

Jan 1, 1990

By J. Philip Neal

Feldspar is no example of special mineralization in isolated spots: it can usually be found within a mile or so of almost anywhere. Along with silica sand, it is a major part of our world's total mineral composition. This fact imparts to it an economic status different from a sulfide ore, or potash, or phosphate. While every feldspathic "stringer" does not possess economic potential, the generous distribution does yield a high statistical frequency of good feldspar ore bodies: the adjective "good" being subject to some flexibility of interpretation. The strong chemical bonds of this alkali aluminum silicate give it certain use advantages, but under present technology its individual elements cannot practically be separated to create aluminum, potassium, sodium, silicon - or their oxides. Its present uses rely upon chemical inertness - as in fillers; and on its physical melting characteristics and their effect in glass, enamel, or ceramics.

Jan 1, 1973

By A. S. Macfarlane

Over the last few years, and especially the last few months, issues relating to Corporate Governance in industry in general, and the Minerals industry in particular, have become increasingly topical, as a result of a number of scandals and failures. The development of International and National Codes for the reporting of Mineral Resources and Reserves began some years ago, and has been followed by more stringent Listing Rules for the Securities Exchanges, as well as more standardised formats and protocols for financial reporting of assets and activities. More recently, some countries have adopted Codes for the Valuation of Mineral Properties, which have focussed on standardisation of valuation approaches to be adopted, and the qualifications of people deemed competent to sign off such valuations. This process has not been without criticism, the main criticism being the proliferation of local standards and regulations, which are often difficult to apply and regulate, or which are too prescriptive for multinational mining companies to deal with. In South Africa, these concerns have been recognised, while at the same time a need has been identified to establish a Code which could be applied to South Africa, and the African continent as a whole. Such a development would necessitate that the Code satisfies the needs of the continent, but in a global context. This global context has already been set by the activities of the International Organisation of Securities Commissions, the International Valuations Standards Committee and the International Accounting Standards Board. This paper explains the progress and process that has been established in South Africa for this purpose, and highlights the key issues which are open to public debate, so that the process is inclusive and transparent, whilst at the same time it is consistent with international time frames, and provides a deliverable product that meets the desired objectives.

Jan 1, 2004

By William R. Yernberg

Santa Fe Pacific Gold, headquartered in Albuquerque, NM is expanding its operation at the Twin Creeks Mine in Nevada. The $250-million sulfide expansion project, including the Sage Mill, is under construction and is 80% complete. Also, additional mining equipment has been purchased to haul the sulfide ore to the mill. With the expansion, employment at Twin Creeks is expected to reach approximately 970 people by the end of 1996. Santa Fe Pacific Gold now owns and operates three gold mines in the United States and is involved in several other gold projects. The three currently operating mines are the Twin Creeks, Mesquite and Lone Tree mines. The Mesquite Mine is located in California’s Imperial Valley. Lone Tree is located 55 km (34 miles) southeast of Winnemucca, NV. The company’s total gold production from these operations is expected to be in the range of 26.3 to 26.6 t (845,000 to 855,000 oz) in 1996. This compares to a total production of about 124 kg (4,000 oz) for the company in 1989. Production costs range from $6.90to $7.25/g ($215 to $225/oz). At the end of 1995, the company reported proven and probable reserves of 556.7 t(17.9 million oz) of gold.

Jan 1, 1996