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By Gordon C. Gutrath

Queenstake Resources Ltd. has been exploring and mining alluvial gold deposits in the Yukon Territory and British Columbia since 1980. The five mines in production produced, in 1987, a total of 13,222 ounces. This paper will briefly review Queenstake's exploration program, property descriptions and mining methods, environmental concerns and a comparison of costs. (Sueenstake has been successful in developing a cash flow base from these operations that provide the capital for the acquisition and exploration of new, and hopefully, larger scale gold producers. NOTE: The historic alluvial mining unit of ounces per cubic yard and English units of measurement have been used throughout this paper. Dollars are Canadian unless otherwise noted.

Jan 1, 1988

By J. P. Nairn, C. M. McCulloch

More and more underground mining is being conducted using the long wall method. Likewise, many new surface mines use area or mountaintop removal methods. These methods can have a significant impact on surface and ground water resources. The overall study of the effects on surface and ground water from mining is referred to as the probable hydrologic consequences (PHC) determination of mining and reclamation. Collection and interpretation of information concerning ground water and surface water quality and quantity, as well as detailed geologic analysis, is required to adequately define the impacts of mining. This paper discusses the present day requirements and methodology of preparing a PHC for a large mining operation in the eastern coalfields.

Jan 1, 1997

By M. Stoica

Bioremediation is a complex process which involves mass transfer, chemical and biochemical phenomena. In particular, the adsorption kinetics of a substance by biomass may by model by taking into account: - Enzymatic kinetics type; - Combined kinetics - enzymatic kinetics at the same time with the Monod type biomass growth; - Chemical kinetics for substance adsorption according to Freundlich and Langmuir ad-sorption isotherms; - New empirical kinetics models based on experimental data. In this paper modelling of kinetics of bivalent lead ions on live vegetal biomass (aquatic plant Pistia stratiotes) as well as of hydrocarbons on dead vegetal biomass (pyrolysed nuts) is studied (Stoica, 2004). Modelling was carried out using experimental data and relative equations with an error of 5%.

Jan 1, 2006

By Abdullah Arik

In deposits with highly skewed grade distributions, such as precious metals deposits, proper handling of the outlier high grade data is very crucial to the ore reserve estimation. Although some recent geostatistical techniques are available to handle the estimation problems with these outlier data, ordinary kriging or conventional methods are still widely used to estimate the ore reserves for such deposits. One reason for this is the fact that the alternative methods offered are either too complex or too exhaustive for the mine engineers and geologist who often do not have the expertise or the time to apply these methods. This paper presents a new 2-step kriging algorithm "Outlier Restricted Kriging" (ORK) which can be a simple and a practical tool to use where the ordinary kriging will fail to handle the outlier high grade data properly in block grade estimation. The paper details the methodology and discusses the results of its application to a gold deposit.

Jan 1, 1992

By R. Jin

The hydrophobicity of six coals ranked from lignite to anthracite is studied through contact-angle measurements, bubble attachment-time measurements, FTIR spectroscopy, and Hallimond-tube flotation. The preliminary study shows that the hydrophobicity of coals can be told by the bubble attachment times of coals (a kinetic criterion) or by the contact angles (an - equilibrium criterion). A general agreement between flotation response of coals and measured bubble attachment times or contact angles is observed in the present study. However, the study also shows that the hydrophobicity of coals can be predicted by FTIR spectroscopy work with proper manipulation of the spectra. Both hydroxyl and carboxyl groups in the coals are proven by FTIR work to be responsible for the change of coal hydrophobicity. A new criterion for the hydrophilicity index of coals from FTIR spectra is introduced through the study.

Jan 1, 1987

By R. B. Massy-Greene

Project engineering and development is a process of optimisation of capital, operating and financial costs, and extraction rates in the light of current and forecast economic conditions for the sale of the product. The aim of the process is to maximize financial returns to the sponsors (project owners) within many often conflicting constraints. Thus, the sponsor's engineering and financial staff have a common goal, with performance measured in financial terms. Consequently, each group must be aware of, and responsive to, the constraints imposed upon the other. For financial staff, the increasing size and complexity, and escalating capital costs of new ventures have required them to seek finance in larger amounts, and by non-traditional methods. In addition, senior management are requiring indications of the availability of finance as a pre-requisite to a decision to commence project development activities.

Jan 1, 1982

By Steven A. Bradbury

INTRODUCTION Passive dust control systems are quickly gaining acceptance in the bulk solids handling industries. The number of applications is increasing due to proven performance, especially in US power plants burning Powder River Basin coal. Air Control Sciences ®, Inc., of Boulder, Colorado, has over forty (40) patented Dustless Transfer ® systems in operation. All of the installations control workspace dust levels to less than 2.0 mg/m3, and in some applications reduced conveyor dusting by over ninety-eight percent (98%). Passive systems control fugitive dust emissions by minimizing the induced airflow in bulk material transfer and slowing its velocity. Traditionally, fugitive dust control in the mining industry was accomplished using either dust collection systems or dust suppression systems. The term passive dust control, indicates these methods don't use any active dust collection or suppression. Passive dust control systems are best suited to transfer from one conveyor to another. They can also be applied to transfers from feeder to conveyors.

Jan 1, 2004

By Charles D. Litton, Margaret R. Egan

In order to reduce the number of nuisance fire alarms in underground mines that use diesel-powered equipment, the U.S. Bureau of Mines has developed a diesel-discriminating fire detector (DDD). It was designed to discriminate between smoke produced by a fire and the smoke-laden exhaust of a diesel engine. Welding and cutting with arc or flame can also produce combustion products capable of triggering nuisance alarms. In this report, the response of the DDD to the emissions from diesel exhaust, arc welding, and flame cutting are compared to the response of conventional smoke and carbon monoxide (CO) detectors. The data show that when the DDD is set at an alarm threshold of 0.05 v, it will reliably detect a developing conveyor belt fire while remaining insensitive to other sources of nuisance combustion products. The alarm times of the three types of detectors were also compared. The DDD alarmed first in response to a smoldering conveyor belt in two of four experiments.

Jan 1, 1992

By Gerald H. Luttrell, Joe Shoniker, Jaisen N. Kohmuench, Christopher J. Barbee, Michael J. Mankosa

The HydroFloat technology was specifically developed to upgrade phosphate sands that are too coarse (>0.6 mm) to be efficiently recovered by conventional flotation methods. In this novel process, classified feed is suspended in a fluidized bed that has been aerated using an external sparging system. The air bubbles selectively attach to particles that have been made hydrophobic through the addition of a fatty acid collector. The teetering effect of the fluidized bed forces the low-density bubble-particle aggregates into the overflow, while hydrophilic particles are rejected as a high solids content underflow Since the HydroFloat is actually a density separator, the process can treat much coarser feeds than would be possible using traditional flotation processes. In addition, the high solids content of the teeter bed promotes bubble-particle attachment and reduces the cell volume required to achieve a given capacity. This paper presents test data from ongoing pilot-scale trials of the HydroFloat cell in the phosphate industry.

Jan 1, 2002

By Edward R. Torak

The Ohio Coal Testing and Development Research Facility (OCTAD) was commissioned in 1992 by the Ohio Coal Development Office and the Ohio Power Company to support evolving process technologies that will lead to increased environ- mentally sound use of coal. OCTAD is equipped with advanced physical concentration devices and processes capable of beneficiating coal to levels beyond conventional practice. The first task of OCTAD operators was to test the cleanability of the Meigs Creek Seam Coal in advanced circuitry and compare the results to conventional cleaning levels. In testing the seams, OCTAD circuitry was configured to produce middlings on the coarse and intermediate size fractions. These middlings were subsequently crushed to a finer size (28M x 0) and subjected to cleaning in fine heavy-media cyclones and advanced froth flotation circuitry. Nearly thirty-six full-scale production runs at various operating conditions were completed during the campaign. The results of the test program are examined in this paper.

Jan 1, 1995

By O. Olajide, E. H. Cho

A laboratory study of the jigging process with Pittsburgh seam coal has been conducted. The laboratory-scale Baum jig used in this study was a McNally-Norton LO30X Right Hand Model Baum jig with an effective screen area of 0.186 m2 Feed material was prepared by selecting a size range from 6 mesh to 1.91 cm. Solid feed rates were 27.2 kg/min and 32.7 kg/min. Water flow rates were varied from 37.9 to 94.6 L/min. It has been found that smaller particles give higher values of density of separation and lower efficiency of separation. Increasing water flow rate increases the discharge rate of clean coal at a constant solid feed rate. It appears that the efficiency of separation increases by increasing water flow rate up to a certain value, and then levels off upon increasing the flow rate further.

Jan 1, 1988

By Dale R. Ralston, Roy E. Williams, Gerry V. Winter, George L. Bloomsburg

GENERAL STATEMENT Data frequently can be collected by several dif¬ferent methods. The method required for the nec¬essary precision for inflow prediction to mines should be selected and other methods avoided. Pre¬cision monitoring or measuring techniques fre¬quently require more time, expertise, and expense in their implementation that may not be justifiable. The temporal distribution of the data needs also may dictate the method used for data collection. Continuous recording devices may be required for time sensitive data whereas point measurements of other parameters may be adequate. Data needs will vary as the hydrologic investigation proceeds. In¬itial data needs may require only a qualitative col¬lection of data such as the areal distribution of precipitation. Subsequent data needs may require the measurement of ground water levels to the near¬est hundredth of a foot. Data requirements can be difficult to fulfill for ground water systems. This is particularly true for anisotropic, heterogeneous hydrostratigraphic units since the hydrogeologic parameters vary both ver¬tically and areally. Techniques exist for determining the storage characteristics of both unconfined and confined hydrostratigraphic units but these pro¬cedures require the installation of multiple wells in the same unit which may be impractical. Specific tests are discussed subsequently that permit the determination of vertical hydraulic conductivity. Data collected from field procedures or tests are generally preferred to laboratory derived data. This is especially true for hydrogeologic parameters such as hydraulic conductivity. SURFACE WATER SYSTEMS Precipitation Precipitation data can be collected from sources that maintain a historical record. The US Depart¬ment of Commerce, National Oceanic and Atmos¬pheric Administration (NOAA), maintains weather observation stations across the country. Such a sta¬tion frequently can be found near a proposed mine site but the type of weather data collected varies from station to station. Fortunately, precipitation data are collected ubiquitously. The data collected by NOAA can be purchased for the area of interest in the form of monthly and annual tabulations. Private weather stations constitute a second source of precipitation data. Existing data usually are analyzed by one of three methods. The station average method merely sums the depth of precipitation at each station and divides the sum by the number of stations as fol¬lows: [ ] where Pavg is the average precipitation (L), P, is the depth of precipitation at station i (L), and N is the total number of stations. This method is applicable where there are a relatively large number of stations uniformly distributed across the area (Hjelnfelt and Cassidy, 1975, pp. 71-72). The second method, called the Thiessen poly¬gon method, weights the precipitation at each sta¬tion in direct proportion to the area it represents without consideration of topography. The stations are plotted on a map and perpendicular bisectors are drawn on the lines connecting the stations. The polygons formed by these bisectors constitute the area that the precipitation for that station repre¬sents. The overall precipitation can be calculated with the following equation:

Jan 1, 1986

By Gretchen K. Hoffman, George S. Austin

Soil amendments or soil conditioners generally carry the con- notation of being useful for problem soils or soils needing special treatments to produce maximum yields. Many different materials have been utilized, both inorganic and organic. Only the most commonly used and those that appear to have potential to become commonly used will be discussed. Soil productivity depends on many factors. Soil amendments mainly modify physical characteristics and microbial action, and/or change the pH of a soil, rather than directly supplying plant nutrients. They give soil the needed physical properties to allow plant growth, fight erosion, or save water. Some soil amendments provide nutrients in addition to altering the physical, biological, or chemical characteristics of soil. The term "soil amendment," as it is used by Soil Science Society of America, allows soil amendments to be materials other than those used primarily as fertilizers (Anon.,1987). Soil amendments as fertilizers of any type will not be considered here because this aspect is more relevant to the previous chapter entitled "Agricultural Materials: Fertilizers" in this volume. Several inorganic soil amendments have been used since the early 20th century to alter the character of soil: limestone, lime, and similar calcium-rich carbonates and oxides for acid soils, and calcium sulfate (gypsum) and native or uncombined sulfur for alkaline soils. The use of these amendments (limestone, lime, gypsum, and sulfur) or their equivalents has been studied and documented in many basic soils tests (McCaslin and Boyle, 1980). Perlite and vermiculite are considered in separate chapters and only a brief statement of their use as soil conditioners will be made in this chapter. Peat is the principal natural organic soil amendment, but manure, both as a fertilizer and soil conditioner, is used in every part of the world. In less-developed countries, manure is the primary soil fertilizerlconditioner. An organic-rich material designated as "humate" has been marketed as a soil amendment for many years and will be addressed in this paper. Other materials are discussed by the Soil Science Society of America in its Special Publication 7, "Soil Conditioners" (Stewart, 1975). They include bitumen emulsion, polyacrylamide, polyvinyl acetate, polyvinyl alcohol, bentonite, nonionic surfactants, and natural mulches. Zeolites can be added to the list of miscellaneous soil amendments (McCaslin and Boyle, 1980), as can calcium chloride (Pressler and Pelham, 1985), sulfuric acid, ferric and ferrous sulfate, aluminum sulfate, ammonium polysulfide, calcium polysulfide, and ammonium bisulfite (Stromberg and Tisdale, 1979). Sludge will not be considered as a soil amendment because it has properties more consistent with fertilizers. All these "other materials" account for a very small amount of the volume and value of soil amendments used and will be only briefly discussed.

Jan 1, 1994

By William D. Leech, Peter S. Buskirk

Virginia Electric and Power Company commencing in early 1985 will begin operating the Bath County Pumped Storage hydroelectric facility, presently the largest capacity installation of its kind. Six concrete lined vertical shafts, 3 ea x 44.0 ft (13.4m) diam x 330 ft (100m) and 3 ea x 28.5 ft (8.7m) diam x 740 ft (226m), comprise a portion of the three underground power conduits. The project team decided to employ the slipform over the conventional jump form method. This selection was based on the engineer's hydraulic design and the contractor's performance requirements. This paper presents the key elements of the shafts' successful slipform operations. The contractor achieved slip rates as high as 60 ft (18m) per day; and the owner received competent permanent linings as specified by the engineer. The authors describe the team's effort to progressively improve both concrete quality and placement rate.

Jan 1, 1985

By Jorma Miettunen

The Plant. The annual production of the Pyhasalmi mine is 900 000 tons of copper- zinc-pyrite ore containing approximately 0.7 % Cu, 2.5 % Zn and 30 % S. During 1976...1981 altered surface ore, 850 000 tons in all, was also treated at the concentrator. The surface ore was crushed and ground in a separate plant and was then fed into the copper or zinc flotation or was flotated in its own circuit, depending on the degree of alteration and the content of copper and zinc in the ore. The surface ore was exhausted in October 1981. Flotation comprises three consecutive flotation circuits; copper, zinc and pyrite circuit. The zinc circuit includes an open circuit roughing and scavenging. The scavenger concentrate and cleaner tailing are pumped to the middlings flotation. Rougher concentrates of the open circuit and the middlings flotation are pumped to cleaning which includes four stages. Figure 1 describes the flowsheet of the zinc circuit.

Jan 1, 1982

By Ernest E. Thurlow

Introduction Today, more than 50% of rail-carried commodities are mineral industry related, with coal being the most important single commodity moved by rail. In 1980, coal accounted for more than 5.7 million of the total 22.6 million carloads moved by rail. Metallic ores were third behind grain, with more than 1.4 million carloads. Crushed stone, gravel, sand, and other non-metallic minerals totaled almost 2.3 million carloads. Chemicals and allied products, including fertilizer and coke, added another 1.7 million cars, with petroleum and petroleum products totaling 300,000 carloads. Coal Several things happened in the 1970s that gave rise to increased consumption of coal-particularly western coal-and to its dominant position among rail-carried commodities. First, the Clean Air Act of 1970 required generating plants to make significant reductions in sulfur dioxide emissions. To comply, utilities could either invest in scrubbers or switch to low-sulfur western coal. Many opted for the latter. By 1972, increasing demands by the utility companies halted what had been a 25-year decline in national coal consumption. Second, the Arab Oil Embargo of 1973 put an end to cheap oil and gas, limiting their future as fuels for electric generating purposes and increasing the potential for coal. Third, in 1977, President Carter announced an energy program with coal as its cornerstone, calling for an annual two-thirds increase in national coal production by 1985. He also called for conversion to coal by utilities and large industrial users. Finally, he proposed a 10-year, $10 billion program to encourage domestic coal production and stimulate development of export markets. Coal bounded into world prominence. Foreign demand for steam and metallurgical coal increased tremendously, while US demand for western coal also shot up. This meant greater demands on the transportation sectors that traditionally carried coal to market. Many railroads began programs to serve the coal industry. One example is Burlington Northern's commitment to handle increased western coal tonnages. The company spent more than $1 billion in recent years to develop a system capable of moving more than 91 Mt (100 million st) of coal each year. Other leaders in this renewal were Norfolk and Western, Union Pacific, Santa Fe, and Southern Pacific railways. The importance of the rapid growth of coal traffic to the railroads is shown in the accompanying table, which gives percentages of total tonnages hauled and revenues attributed to coal. With coal providing the railroad industry with a substantial share of its revenues, there is keen competition among the rail companies themselves and among railroads and other transportation sectors for coal haulage. But there is also cooperation when more than one railroad is involved in delivering the coal from mine to market or when a combination of transportation modes is more economical. The latter is represented by Conrail's interest in working with the port authorities of New York and New Jersey to establish a new coal port that would serve not only export markets, but also utilities and industries in the northeast. Iron Ore Next to coal, iron ore (taconite) is the most important single mineral commodity handled by railroads. In Minnesota, where most iron ore is produced, rail transportation is primarily by Burlington Northern and the Duluth, Missabe, & Iron Range Railway Co. (DM&IR). The DM&IR, owned by US Steel, serves several producers on the Mesabi Iron Range. Two of the larger producers, Erie Mining Co. and Reserve Mining Co., also own railroads that operate between the mines and the ports of Silver Bay and Taconite Harbor on Lake Superior. Several iron mines and taconite plants in Michigan are served by the Chicago and Northwestern, and the Soo Line. Total 1981 shipments of taconite and iron ore are estimated at 55.9 Mt (55 million It), compared with about 61 Mt (60 million It) in 1979 the most ever shipped in one year. Still, with annual production capacity of the eight Mesabi Range

Jan 10, 1982

By J. D. Miller, Z. S. Nickolov

Sum Frequency Spectroscopy (SFS) is a powerful nonlinear optical technique to study interfaces at the molecular level. SFS has one major advantage over conventional vibrational spectroscopic methods, such as infrared (IR) absorption and Raman scattering, in that the method is inherently interface specific. As a result, the spectroscopy of molecules residing in the interfacial region can be probed selectively without any contributions from the molecules present in the more pervasive bulk phases. Analysis of SF spectra can yield information on population, structure, and orientation of interfacial species with several nanometers in-depth resolution. The recently acquired SF spectrometer at the University of Utah opens new possibilities for investigation of interfacial phenomena of great importance for separation technology, materials research, nanotechnology, bioengineering. Its application to studies of liquid/gas, solid/liquid, and solid/gas interfaces will be discussed.

Jan 1, 2004

By R. A. Basse, W. D. Diment, A. J. Petrina

INTRODUCTION In 1957, diamond drilling on a magnetic anomaly indicated an extensive zone of copper mineralization on what is now the Craigmont Mines property. By mid¬1958, drilling established a copper ore body. Milling commenced in September 1961 at 4536 t/d (5000 stpd) and by the end of October 1977 the mine had produced 339 662.04 t (374,363.9 st) of copper. At present, two-thirds of the mill feed is derived from underground operations and one-third from low-grade surface stockpiles. Craigmont Mines is situated 209 km (130 air miles) northeast of Vancouver (see Fig. 1), 16 km (10 miles) west of the town of Merritt, a logging, ranching, and mining community of about 7000 people. It is serviced by paved highways, Canadian Pacific Railway, British Columbia Hydro, and Inland Natural Gas Co. Water is pumped from the Nicola River, a distance of 6 km (4 miles) and a lift of 244 m (800 ft). In March 1967, the open pit mining operations at Craigmont Mines reached their economic limit and were suspended. Before this, it had been decided that a sub¬level caving method of underground mining would be used to supply ore to the concentrator after the cessation of open pit production. This chapter describes the fac¬tors influencing the choice of mining method, some of the problems encountered, mining practices, and results. GEOLOGY The ore bodies of upper Triassic age are located in a limy horizon striking east-west, closely paralleling the intrusive Guichon batholith, bounded on the south by rhyolites and on the north by graywackes, and dipping steeply to the south (Figs. 2a, b). The ore bodies are relatively narrow with a maxi¬mum width of 79 m (260 ft), a combined strike length of 853 m (2800 ft), and a vertical extent of 610 m (2000 ft). Chalcopyrite is virtually the only copper mineral, and 20% of the ore zone consists of acid solu¬ble magnetite and hematite. The area has been subjected to considerable faulting and brecciation, which is a major factor in the mining operation. Total geological reserves, at 0.7% Cu cutoff, for the deposit were 22 316 743 t (24,600,000 st) at 1.89% Cu. An additional 5 236 270 t (5,772,000 st) at 0.6% Cu were mined from the open pit. Ground Conditions The waste rocks-graywacke, andesites, and diorite -are relatively incompetent due to the high degree of fracturing and jointing, and all require varying degrees of support. The ore zones are somewhat less fractured; ground support is still required, however, although to a lesser extent than in the country rock. Ground conditions in the main ore body are better than in the smaller, nar¬rower ore bodies. Clayey fault gouge is present in most of the faults; gouge zones may be up to 6 or 9 m (20 or 30 ft) wide. The main ground problems are associated with local weakness rather than pressure. Shape of Ore Bodies (Figs. 2a, b and 3a, b) The main No. 1 ore body is approximately 244 m (800 ft) long and 46 m (150 ft) wide. It extends ver¬tically from the original top of the open pit at 4200 ele¬vation to just below the 3060 level. The No. 2 ore body is approximately 304 m (1000 ft) long, varies from stringer width at the extremities up to 79 m (260 ft) wide, and extends from 3060 level to 2400 level. Both these ore bodies have extensions re¬sulting in additional small irregular bodies. Ore bodies are mostly steep dipping, though part of the Wing ore body, an extension of No. 2 ore body, dips at 0.87 rad (50'). This ore body varies in size, but is approximately 122 m (400 ft) long, 21 m (70 ft) wide, and about 213 m (700 ft) high. No. 1 Limb ore body is a narrow extension of the No. I Main with a vertical extent of 137 m (450 ft), average width of 18 ft (60 ft), a strike length of 152 m (500 ft), and dips steeply at 1.4 rad (80°). No. 1 East is an eastern extension of the No. 1 Main with a vertical extent of 183 m (600 ft), a strike length of 91 m (300 ft), an average width of 30 m (100 ft), and dips at 1.2 to 1.4 rad (70 to 80°). No. 1 South is at the upper west end of the open pit with a vertical extent of 76 m (250 ft), a strike length

Jan 1, 1982

By M. D. Flavel

Testing methods are described to help in decisions of selecting the most viable comminution circuits. The authors present a comparison evaluation based on numerous studies to help make initial choices for feasibility evaluations. An update summary of completed Bond grindability and Abrasion Index testwork at Allis-Chalmers Process Research Test Center for all materials is included. "What is the best circuit to comminute primary crusher product to make beneficiation feed?" This frequently asked question has the implication that there is one circuit which is universally the right circuit. The answer has been sought ever since it has been necessary to break rock to liberate entrapped mineral values. With every new contribution to the art and the science of comminution, the scope of the discussions broaden. It is not even possible to define what the abstract term best means.

Jan 1, 1981

By Roderick K. Davey

Kennecott Copper Corp.'s Metal Mining Div. operates three major open-pit copper mines in the western United States. These operations include Utah Copper Div., Ray Mines Div. in Arizona, and Chino Mines Div. in New Mexico. At each of these operations, the material is loaded by large electric shovels and transported by both truck and rail haulage. In 1977, 197 350 774 t (217,542,000 st) of ore and waste were mined at these operations, and 302 040 t (332,942 st) of copper were produced. Also a significant amount of molybdenite was produced as a byproduct. In operations as complex and large as these, there is an inherent need for up-to-date reports concerning how much material was mined during the previous day, and year-to-date, what equipment is scheduled for maintenance, how equipment has been performing, etc.

Jan 1, 1979