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The 18th annual American Mining Hall of Fame Awards Banquet sponsored by the Mining Foundation of the Southwest will be held on Saturday, Dec. 2, 2000 at The Westin La Paloma in Tucson, AZ. The 2000 inductee, guest of honor and featured speaker at the banquet will be Ronald C. Cambre, chairman and chief executive officer of Newmont Mining. He will be honored for his role in positioning Newmont as an innovative and key player in the gold mining industry.

Jan 1, 2000

By D. G. Klaren

Self-cleaning fluidized bed heat exchangers are conquering the world for reason that they are able to solve any severe fouling problem in indirect heat transfer due to the circulation of cleaning particles through the tubes of vertical shell and tube exchangers. In most cases, these particles consist of chopped metal wire. Moreover, self-cleaning fluidized bed heat exchangers perform with excellent heat transfer at very low liquid velocities, which makes completely new designs of shell and tube configurations possible. Further, self-cleaning fluidized bed heat exchangers show a strong shear thinning effect in non-Newtonian liquids. All the above characteristics make the self-cleaning fluidized bed heat exchanger an ideal tool for the indirect heating of laterite nickel slurry in High-Pressure-Acid-Leach (HPAL) plants. Preliminary tests and evaluations of these heat exchangers have shown that the performance and price of these heat exchangers used for the production of nickel and cobalt from a laterite slurry, cannot be matched by existing conventional heat exchange systems. This article explains the principle, design, lay-out and enormous advantages of the self-cleaning fluidized bed heat exchange technology in a plant suitable for an annual production of approx. 45,000 ton nickel and 4,500 ton cobalt from laterite slurry through high pressure'acid leaching.

Jan 1, 2002

By M. Hamarat

Freeport-McMoRan Copper & Gold (FCX) is committed to preserving and enhancing biodiversity in the areas in which we operate. As a member of the ICMM, FCX is committed to implement the 10 Sustainable Development (SD) Principles throughout our business. FCX is also a member of the Wildlife Habitat Council (WHC), a nonprofit coalition dedicated to protecting and enhancing wildl ife habitat. In alignment with ICMM SD Principle 7 and our Environmental Policy, FCX has set a performance goal to prepare a biodiversity inventory in 2010 and land management plan by end of 2011 for all active mining sites. In 2010 FCX established a Biodiversity Task Force to assist sites in biodiversity management; optimize use of resources around the globe; implement FCX goals and targets; and align biodiversity programs with ICMM principles and guidance. The task force consists of Environment and SD Department management, scientists and engineers from FCX sites, and WHC staff. The Task Force recently issued a biodiversity inventory guidance document to set expectations and provide consistency across the sites when developing a biodiversity inventory and land management plan.

Jan 1, 2011

By Glen Church, Don W. Deere, Christoph M. Goss

The Standley Lake Dam Rehabilitation Project in Colorado included the complete replacement of the outlet works. This required two 1.8m (6 ft) diameter microtunneled wet lake taps, 380m and 186m (1246 ft and 636 ft) long, a permanent valve shaft 12.2m(40 ft) wide and 32m (105 ft) deep, and a 3.5m (11.5 ft) diameter (962 foot long) outlet tunnel driven with a roadheader. The tunnels were driven in low-strength, expansive, and slickensided claystone. The paper addresses the site investigation, shaft construction, roadheader performance, shotcrete placement, tunnel convergence, long distance microtunneling, and wet lake taps.

Jan 1, 2005

By L. Ozdemir, M. Cigla

This paper presents and discusses some of the computer models developed and currently used at the Earth Mechanics Institute (EMI) of the Colorado School of Mines (CSM). These include the performance models for full and partial face machines. Examples of input and output of these models will be illustrated for typical mining operations by using machines such as Tunnel Boring Machines (TBM), Continuous Miners (CM), Marietta borer miners and longwall drum shearers. The general approach to modeling and the available models are discussed and some examples of these models are presented. The comparison between the estimated and achieved performance, as well as the degree of improvement in the performance due to balancing and modification in cutterhead design are also discussed.

Jan 1, 2000

By Kelvin K. Wu, George H. Gardner

On July 24, 2002, a nonfatal entrapment accident occurred at the Quecreek #1 Mine, Black Wolf Coal Company, when an active mining section inadvertently cut into a flooded abandoned mine. This incident, and the dramatic rescue which ensued, brought national attention to a common problem in the coal mining industry. Since 1995, there have been more than 100 inundations at coal mines in the United States. Unavailable, inaccurate, or incomplete mapping of older abandoned mines is typically responsible. Serious problems associated with accidental discharges of fluid mine waste material (slurry) and water from coal refuse disposal facilities have resulted from similar causes. Recent problems related to the inaccurate location of old abandoned mine works have increased the interest in the use of conventional and emerging drilling and geophysical techniques for detection of air-filled and water-filled cavities. The United States Congress has committed significant funding toward investigating the applicability of these technologies. MSHA actively promotes the use of the best available technology to minimize the significant adverse safety and environmental consequences associated with unplanned breakthroughs and inundations. This paper provides background information and a general summary of the MSHA-sponsored field demonstration projects which are currently in progress. Potential benefits and limitations are discussed. The need for field verification/ground-truthing is emphasized. Under appropriate conditions, geophysical methods can be effectively integrated into a comprehensive field exploration program.

Jan 1, 2005

By J. O. Voigt

No major changes took place in the salt industry during 2004. No new uses of salt appeared and only localized supply disruptions occurred. Many salt producers reported slightly increased salt sales and profits for the year. In the United States, about half of the salt supply is produced as brine, by solution mining, and is used by the chemicals industry. One-third of U.S. salt is produced as rock salt by 14 underground mines. The remaining two production techniques, each with less than 10 percent of the total tonnage, are vacuum-pan-evaporation for refined, food-grade salt, and solar pond crystallized salt.

Jan 1, 2005

By Andreas Prucker

The Greater Vancouver Water District (GVWD) is currently constructing the largest water treatment plant in Canada. As part of this treatment scheme twin water transfer tunnels are being constructed. Work commenced with the 11 m diameter, 185 m deep Seymour Shaft which was excavated by drill and blast using a mobile crane for hoisting. The Seymour Shaft is the first large diameter shaft that has been sunk in Western Canada in recent years. The operational aspects associated with the hoisting, the drill-blast-support cycle and water control in the shaft are the focus of this paper.

Jan 1, 2008

By Glen Frank, David R. Chapman

Determining the number of boulders and cobbles that will be encountered in the tunnel envelope is one of the most difficult problems confronting the geotechnical engineer in the design of tunnels in glacial terrain. This issue is very important to the contractor, both in determining what methods will be used to construct the facilities and the advance rate that can be achieved for the chosen construction methods. The cost of constructing tunnels by pressurized face tunneling techniques is very sensitive to accurate characterization of the very coarse fraction (large cobble and boulder sized clasts), and no standard method is current available for characterizing boulders and cobbles. Careful use of large diameter borings and the sampling and analytical techniques outlined in this paper can provide a means to answer this difficult question. By performing large diameter borings and carefully recording and sampling the cobbles and boulders encountered, an estimate for the amount of these materials present in the formations sampled can be provided. Using this method allows the designer to communicate the expected geologic conditions to the prospective bidders in a manner that is both definitive and defensible. This paper describes the method as it was used in conjunction with the design of a large diameter sewer tunnel in the Columbus, Ohio area.

Jan 1, 2005

By David A. Brence, Andrew D. Marti, Richard P. Stahura, Ronald J. Valentine

The development of an effective belt-cleaning system for a new conveyor system seemed a fairly conventional assignment. But a closer examination of the project showed a number of “fine print” details: •High altitude location (with resulting cold weather and low humidity conditions). •Long conveyor length. •Troublesome material (very sticky and capable of hardening like concrete). •Limited water. These difficulties are spelled out the challenge of developing a cleaning system for the production conveyor2 (PC2) belt at Climax Molybdenum’s Henderson Mine.

Jan 1, 2005

By R. Rushforth

The surge of activity in the solar energy market, spurred by government incentives, has created new and more efficient solar technologies, but issues surrounding land- and water-use have backlogged the full-scale development of solar farms. This paper explores siting solar power plants on degraded or polluted lands, such as mine tailings impoundments. Historically, mining and has been integral to Arizona?s economy, but has dwindled in relevance due to urban pressures and environmental regulations. Currently, it is legal to site solar power plants on degraded or polluted lands, but the question remains whether the economics of this degraded lands solar development is more favorable than developing pristine land. Therefore, we explore economics of developing mine tailings impoundments at both the institutional and financial level. Methods of research for this paper were interviews with government regulators, environmental advocacy organizations, farmers, and mining company executives. Financial models using extant tax incentives show a positive net present value for the installation of solar power plants, even when accounting for the costs of land remediation.

Jan 1, 2011

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

Electrostatically charged water droplets efficiently suppress breathable dust produced during open air rock crushing operations, according to recently completed independent tests conducted for the Environmental Protection Agency. Since a primary rock crusher produces very heavy clouds of dust, this application was selected as an appropriate test site to measure the efficiencies of new "charged fogging" equipment in mining and mineral processing operations. EPA's Industrial Environmental Research Laboratory, Research Triangle Park, NC, contracted TRC-Environmental Consultants Inc. of Wethersfield, CT, to conduct a full-scale demonstration of a recently developed electrostatic fogger, designed to project a charged fog spray at distances up to 15.2 m. Test results indicated overall fogger efficiencies of approximately 70%. The Fogger IV* employed in these tests is reportedly the largest charged logger ever made, with an extremely long operating range. The original fogger was designed for indoor dust control; this fourth generation version is designed for fugitive dusts, indoor and outdoor, and has an operating range up to 15.2 in.

Jan 6, 1981

By D. Mohapatra

The possibility of using 2,2,4-trimethyl-1,3-pentanediol dissolved in tetrachloromethane as extractant for boron recovery is discussed. The parameters optimized for this purpose are contact time, boron concentration in the aqueous phase, extractant concentration, equilibrium pH and phase ratio. NaOH is used as stripping agent for boron recovery from the loaded organic phase. Boron extraction is found to be a slow process (equilibrium time 20 minutes) compared to boron stripping, which is reasonably fast (equilibrium time 5 min). Maximum boron extraction is possible at a broad pH range from 1.0 to 6.0. Using 1.0M extractant concentration, a 1:1 phase ratio (organic: aqueous) and two stages, ~99% boron extraction is achieved. More than 97% boron stripping is possible using 0.5M NaOH at a 1:1 (organic: aqueous) phase ratio in two stages. Overall, a 95.6% boron recovery was achieved. Loss of solvent into the aqueous phase and co-extraction of Ca, Na and K into the organic phase at higher equilibrium pH are two major concerns in his process.

Jan 1, 2008

By P. A. Plunkert, D. E. Morse, L. McCartan, J. F. Papp

The mineral sector is a fundamental part of the U.S. economy. It contributes to the real gross domestic product (GDP) at several levels — basic (mining), intermediate processing, manufacturing of finished goods and construction. The real GDP during 2004 increased by 4.4 percent. The nominal GDP was about $11.7 trillion. Housing starts were up by slightly more than 4 percent for the year. And the nation’s unemployment rate decreased to5.5 percent in 2004 from 6 percent in 2003. Interest rates continued to be low (prime rate was 5.25 percent at the end of 2004) but have risen gradually, following rising inflation.

Jan 1, 2005

By J. Kallioinen

The development of mechanical flotation cells has resulted in larger and better cells. This has led to flotation banks with only a few units, even in large-scale operations. This equipment development makes the old operational considerations ineffective. The flotation cell must be considered as a single reactor unit capable of handling specific tasks and getting excellent metallurgical performance. The result of the unit reactor concept development was the new large TankCell that comes in sizes up to 113 m3 (4,000 cu ft). The TankCell construction includes new modified rotor-stator designs, new tank geometries and a froth-handling capability independent from subprocesses taking place in the pulp (i.e., air addition). The conventional idea of a single flotation cell type for fine, intermediate and coarse materials does not give optimal results. Optimal flotation of coarse and fine particles needs different mechanism designs, impeller tip speeds and different froth control objectives.

Jan 1, 1995

By D. L. Stevens

Following an in-depth scenario and strategic planning exercise in 1997, Noranda’s mine production goal was set at 500,000tonnes per year of both copper and zinc metal within five years. There had been no recent discoveries, reserves were shrinking and things had to be done differently and quickly. Change is now continual in our program but here is what we did first: - Combined the exploration and business development groups - Formed teams to search for and respond to opportunity - Made our geologists more business minded and our engineers more optimistic - Went global - Set clear thresholds, farmed out the marginal properties, fast tracked the others - Focussed reconnaissance exploration where we had a clear competitive advantage - Became a “flexible” partner to both juniors and seniors

Jan 1, 1999

By E. Tulcanaza

M.S. Azun I do not at all agree with the basic points of the author's conclusion. The use of lognormal or normal model to respond to the attribute distribution function should be carefully questioned. If fitting a distribution function of regionalized variables is the main purpose, one may employ one of certain well-known families of distributions, such as Tukey's lambda functions. For instance, the distribution function of gold assay values studied by Krige (Krige, 1978) may fit the lognormal model well, but one should not exclude that the basic idea of using the distribution function of observed data is to have insight of the physical mechanism that gives rise to the regionalized variables. In Applied Geostatistics, there are many examples considering only lognormal or normal model for the distribution function of geostatistical data even if the observed distribution function has more than one mode. Of course, using lognormal or normal model always brings easy computation for the statistical properties of attribute under investigation. Still, I object to adopting any of those models without having any "statistical inference." As seen from the author's paper, lognormal and normal model produce the same average grade (0.746% copper) and almost the same sample variance. Therefore, which model explains the probabilistic behavior of ore deposit is always an important question that should be replied by the geostatistician using not the common sense but the statistical and probabilistic methods. For kriging procedures, such as linear kriging, one should describe either second order stationary properties or bivariate properties of regionalized variables. Second order properties, such as correlogram function or semivariogram function, are the inputs of the so-called kriging equations. Selecting one of any useable models for the observed second order properties, such as spherical model, is not easy since the models are not based on the correlations structure of the regionalized variables. How those models being used in Applied Geostatistics can be distinguished is another important problem. One may develop many fitting models to respond to the observed second order properties of regionalized variables. However, I suggest that the model should be based on the probabilistic behavior of geologic process. The author used spherical model for copper, wolfram, and silver grades from isotropic sector (Fig. 2, 4, 3b) and exponential model for silver grades obtained along raises in isotropic sector (Fig. 3a). It seems that those semivariograms given in Fig. 3b for isotropic sector and Fig. 4 may be described by the random model implying that regionalized variables do belong to renewal process (Azun, 1983). If I knew the total number of data points used in estimation, I may prove that my conclusion is correct. Recalling the test for the first order sample correlogram value, the test procedure is introduced such that the independence is rejected if [ ] where Za/2 is the a/2 percentile of standard normal random variable and N is the total number of samples used in estimation (Azun, 1983). For the other observed semivariogram functions I suggest the author might try to use the so-called "Markovian model" describing not only the correlation structure of regionalized variables, but also the physical mechanism that produces the regionalized variables. The Markovian model for correlogram function is, [ ] The Markovian model for the other second order properties of ReV are also derived. T ve B, in the above equation, show, for example, structural change and mineralizational variation in a considered deposit, respectively (Azun, 1983). In selecting any model, it is not easy to search for the "best" response to the observed second order properties of ReV's. The Markovian model, based on a theoretical understanding of underlying mechanism, gives more information about the occurrence of regionalized variables and respond to all properties. Random model and the so-called hole effect structure can be easily defined as a special form of the Markovian model (Azun, 1983). An estimation of any second order properties of regionalized variables may be computed through (N-1) lag. However, the dependency between the regionalized variables may be deemed to have "died out" after the so-called stationarity width (range). In practice, the estimation is carried out through 25% of the total number samples available. Therefore, the large fluctuations around the zero level and variance for correlogram or covariogram function and semi-variogram function, respectively, cannot be observed. Since the number of pairs involved in the estimation of higher second order properties is small, the estimation variance at those lags is large. There is no need to show higher order estimated second order properties. After using one of any kriging procedure for block estimation, the distribution function of average grades has the same mean as the drilling sample grades but

Jan 3, 1985

To build an effective entry roof beam, a roof bolting or supporting system must be of the ability of providing a clamping force to the bolted roof strata. Currently, two roof bolting systems are widely used to serve the purpose of providing such a clamping force. They are resin and mechanical anchorage bolting systems. Both numerical modeling and double shear testing results indicate that a greater pre-installed load or pretension of a roof bolting system is very critical for effective beam building. Although it?s generally accepted that a mechanical anchorage bolting system can provide a greater pretension than a resin anchorage bolting system does (Su and Poland, 2007 and Peng, 2008), no published field data are available to support such a conclusion. This paper analyzes the results of our field tests on both roof bolting systems, explains why one roof bolting system is better than the other under a typical roof condition, and finally discusses the effective means for coal mine operators to determine the best roof bolting system for their roof conditions.

Jan 1, 2011

By Gary J. Fletcher

Mining and processing activities which are proposed on private land, state leases, or unpatented mining claims are governed by numerous local, state, and federal laws which identify the procedures and conditions which must be met before resources can be developed. The respective government agencies responsible for the administration and enforcement of these laws have promulgated supporting regulations and guidelines, and have implemented certain permit and approval processes to ensure compliance. Each exploration project has a unique environ- mental setting and location which further dictates the types of air, water, hazardous waste, and wildlife laws and regulations which must be complied with before development commences. The environmental planning process should be the first step in the evaluation of existing company properties and the potential acquisition of other mineral properties. However. many company don't consider the environmental requirements for a project until the decision is made to develop the property for mining and processing. If a mining company wants to expedite the environmental planning process, it must first develop an in-house process for evaluating the project and determining the environmental approval procedures in the state where the project is located. The first stage of environmental planning involves general information which can set the overall company philosophy for development of projects.

Jan 1, 1987