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By M. A. Evanto

Since the late 1970's, the Roof Control Division (RCD) of MSHA's Technical Support has been performing linear analyses for the enhancement of miners' safety. This remote sensing process uses Landsat data to predict areas of potentially hazardous ground conditions in underground mines. To date approximately 700 analyses have been completed by the RCD, with nearly 75 being performed with the current equipment, software and methodology which was updated in early 1995. While success is difficult to measure, requests for linear analyses continue to come from large and small mining companies which suggests the industry's acceptance of the process.

Jan 1, 1998

Large variations of coal seam thickness and roof conditions are associated with the occurrence of mine floor undulation at Shoal Creek Mine, operated by Drummond Company, Inc.. Ground control problems, such as roof falls and face failures along with extremely high shield pressure and rapid face convergence, are often reported at the longwall face when these undulations exist. This greatly increases equipment downtime and causes production delays. As a result. a comprehensive study of mine geology including roof conditions and longwall performance were conducted in the mine. With the help of continuous full-face shield pressure monitoring using the Longwall Strata Control and Maintenance System (LoSCoMS), a large data base of shield pressure with various roof conditions has been established. This enables the mine operators to accurately evaluate the roof behavior and shield performance and to take the appropriate operational steps at the face to reduce the number of downtime and face failures. This paper summarizes all works and findings from the study including detailed roof geology and its effect on longwall performance.

Jan 1, 1998

By James N. Brentz

This paper deals briefly with the problem of efficiently selecting the most cost effective haulage truck. Problems and factors are identified that effect productivity and operating cost. Despite the sophistication of computerized vehicle simulation programs, there is a wide disparity in accuracy and methodology, particularly in dealing with the various elements of cost.

Jan 1, 1984

By F. Woller

The territory of Czechoslovakia is well endowed in deposits of a variety of industrial minerals. At present, 29 different types of industrial minerals are mined from some 600 individual deposits in Bohemia and Moravia only. About half of those production centres involves structural materials like aggregate and common brick clays and loams. A significant proportion of industrial minerals produced in Czechoslovakia are exported. Destinations of main products are shown in Figure 1. Production of industrial minerals in Czechoslovakia has a long history. Glass has been produced since the 14th century, sulphuric acid since 1578, graphite since 1750, and chinaware since 1790, to name just a few; but most of the present production comes from deposits developed during the past forty years. For a variety of reasons, only about 30 per cent of registered and explored industrial minerals deposits in the country are in production (Table 1). Two of the reasons may be the complexity of processing or conflicting interests of parties involved, but lack of market research, investment funds, or processing capacity have also had an impact on the level of utilization of the resource base.

Jan 1, 1992

By R. J. Sweigard

Stabilization of slopes on abandoned mine land (AML) invariably involves some channelization to control surface drainage. Typically, these channels are lined with riprap or gabions, depending on gradient and expected flow rate. The conventional treatments pose a problem since they require frequent maintenance and replacement at times. Soil bioengineering presents an alternative to the conventional measures. In soil bioengineering, living woody plant material forms the main structural component in systems designed to prevent shallow mass slope failures, surface erosion, and channel bank erosion. An experimental application of soil bioengineering techniques was designed and implemented at an AML site in eastern Kentucky. The design consisted of live fascines and live stakes using willow branches installed with coir geotextile. Channel gradient, length, and cross-section were considered in the design.

Jan 1, 1998

By G. Troly, M. Esterle, B. Pelletier, W. Reibell

In New Caledonia, ultramafic formations occur on 7,000 square kilometers. Weathering of peridotites leads to profiles of alteration and nickel concentrations. Complete profiles are composed of two main groups of horizons: 1. Limonitic, mainly composed of iron hydroxides 2. Saprolitic, partly composed of magnesium and iron silicates Shape and mineralogical composition of saprolitic horizons are chiefly affected by the nature of the bedrock: types of peridotite and their degrees of serpentinization. On the other hand, morphology (plateau, terraces, slopes, piedmont) is an important factor. Ore-bodies are inside saprolites; their outlines are determined by the grade of nickel and tonnage economically mineable. Information about geology, morphology, geochemistry, and mineralogy are given in this paper.

Jan 1, 1979

By III Feeley

The U.S. Department of Energy is supporting the engineering development of three advanced physical coal cleaning technologies--selective agglomeration, advanced flotation, and advanced cycloning--capable of significantly reducing the pyritic-sulfur content of U. S. coals. The objective of this activity is to provide the coal production and electric-utility industries with a cost-effective option for addressing the SO2 emission reductions required by the 1990 Clean Air Act Amendments. A secondary objective is to evaluate the potential of advanced coal cleaning for removing trace elements that are precursors to the formation of hazardous air pollutants. This paper will summarize the status of the three advanced physical coal cleaning engineering development projects.

Jan 1, 1993

By L. Shwydiuk, A. Chrzanowski, W. Newcomen, G. Bastin, R. Wilkins

Automated monitoring of steep embankments allows the early detection of instability and can be used to avoid or mitigate possible slope failures. A system that uses multiple and different types of sensors has been created and successfully tested at the Highland Valley Copper mine in British Columbia. The system uses robotic total stations (RTSs) as the primary measurement sensor, with surveys repeated at predefined intervals selected to optimize operational efficiency. A methodology has been developed to improve the system’s accuracy and reliability by reducing the effects of systematic errors created by atmospheric refraction and unstable instrument and reference point positions. The inclusion of GPS sensors to monitor the RTS positions creates additional operational flexibility and maintains system integrity when insufficient reference stations are available.

Jan 1, 2003

By L. B. Phelps

This paper focuses on the use of an integrated mine planing software package entitled "REMINE" which was constructed to provide a project evaluation tool for analysis of remining projects. Coal remining constitutes the affecting of sites which have had a past history of mining and have a pre-existing pollutional discharge. Such sites require a Best Professional Judgement (BPJ) analysis. The program was written to provide such an analysis with flexibility in the mine plans which can be analyzed. The process required for a BPJ analysis will be detailed and mine plan simulation performed to demonstrate the analysis.

Jan 1, 1990

By R. Woods

"Comments on the paper ""Formation of hydrogen peroxide by chalcopyrite and its influence on flotation,""by A. Javadi Nooshabadi and K. Hanumantha Rao (Minerals & Metallurgical Processing, 2013, Vol. 30,No. 4, pp. 212-219)The formation of hydrogen peroxide from water during the grinding of chalcopyrite in a nitrogen-sparged environment, as reported by Javadi Nooshabadi and Rao (Minerals & Metallurgical Processing, 2013, Vol. 30, No. 4, pp. 212-219), is questioned on the grounds that oxidation of water by the mineral is unlikely to be thermodynamically feasible. It is argued that it is more likely that any peroxide that had been formed would have been generated from residual oxygen in the nitrogen-flushed system than from the oxidation of water.The formation of hydrogen peroxide by finely divided pyrite had been reported by a number of authors (Borda et al., 2001; Borda et al., 2003; Cohn et al., 2006; Schoonen et al., 2006; Schoonen et al., 2010; Jones et al., 2011; Javadi Nooshabadi et al., 2013). That hydrogen peroxide is formed in the presence of oxygen in solution can be comprehended from wellestablished mechanisms. Pyrite in aerated solution is known to oxidize by an anodic process that is coupled with the cathodic reduction of oxygen (Holmes and Crundwell, 2000). The latter process has been shown to occur through the formation of hydrogen peroxide (Biegler et al., 1975; Ahlberg and Broo, 1996). The pH dependence of cathodic oxygen reduction at other sulfide minerals, including chalcopyrite (Biegler et al., 1977; Rand, 1977), implies a similar mechanism at these surfaces."

Jan 1, 2015

By M. S. Prasad

In earlier work it has been shown that paper filler clay products can be obtained from primary kaolin deposits of Minnesota. The objective of the current work was to reduce silica and iron contaminants and to maximize kaolin recovery to higher value products suitable for paper coating. This results in achieving a finer and cleaner product conforming to paper coating specifications. Cationic flotation and high gradient magnetic separation were used to remove free silica and iron, respectively, while attrition grinding and ultrasonics have been examined for particle size reduction. The results of this work are presented and discussed particularly with respect to application-oriented product properties. Budgetary estimates are presented for a 200,000 ton/year processing plant based on the process flowsheet developed and optimized by the study.

Jan 1, 1991

By Michael A. Linkous, Mark J. Zdunczyk

Silica in the form of sand and sandstone is one of the most common, and at the same time, unique industrial minerals. Found in every rock type of every geologic age and virtually everywhere in the world, silica is used in products that touch just about every aspect of daily life. Imagine a world in the 1990s without computer chips, fiber optics, or glass, and you have just begun to understand how important silica is to the quality of life we enjoy. The elements silicon (Si) and oxygen (0) comprise roughly 60% of the earth's lithosphere to a depth of about 16 km. The crystal structure of silicon dioxide consists of one atom of silicon bonded to four surrounding atoms of oxygen to form a three-dimensional network of SiO, tetrahedra. This network makes up the mineral quartz (Murphy and Henderson, 1983), the most common detrital mineral in most sandstones. Quartz is also a major constituent of many igneous and metamorphic rocks and is widespread as a siliceous cementing agent in various rock types. Although quartz is common, sandstones, quartzites, and pegmatites and the unconsolidated sediments derived from them that have a silica content high enough and pure enough to meet today's market demands for quality and consistency are not common. USES AND SPECIFICATIONS Silica sand that is mined and processed for industrial uses must conform to the chemical and physical specifications set by customers. In the United States almost half of the silica sand produced is used in the manufacture of glass. Other important products include foundry sand, ground silica, blasting sand, and fracturing sand. Glass Sand Silica is the principal glass-forming oxide in a glass batch. Glass manufacturers develop model specifications for each source of silica sand used. These specifications broadly define the limits and ranges for chemical and physical properties of the sand and are used by the manufacturer in calculating the desired batch mix or formula. Some specifications may be critical to a glassmaker and require very stringent limits on the quantity of impurities in the sand. For example, the total iron oxide content of a batch is extremely crucial when making white or flint glasses (Mills, 1983). Iron is present in almost every raw material used in a glass batch and must be carefully controlled in order to obtain a consistent color in the finished product. It is difficult, however, for a raw material supplier to tightly control the chemistry of a naturally occurring material such as silica sand. To a great extent the commercial quality of a sand is determined by its geologic history. Realizing this, glass producers tailor their model specifications to each source of approved material. In general, a glass company is concerned most about the consistency of raw materials on a day-to-day basis. Soda-lime-silica glass was the earliest type of manmade glass (Baker-Can, 1967) and still accounts for most of the glass manufactured for commercial use today (Mills, 1983). It is relatively easy to melt and shape and is less expensive per ton to produce than most other types of glass (Baker-Can, 1967). Soda-lime-silica glass is used in fabricating containers, flat glass products, incandescent and fluorescent lamps, glass fiber, and many other products. Heavy minerals such as ilmenite, leucoxene, kyanite, and zircon are impurities on which strict limits are placed for a glass batch. Because of their refractory nature they either do not melt or only partially melt, which results in stones or feathers in finished glass. Aluminosilicates such as kyanite also contribute unwanted alumina to the batch as they partially melt. Limits are especially rigid for refractory mineral grains coarser than 0.60 to 0.425 mm (30 to 40 mesh). [Tables 1 and 2] present typical specifications for silica sand used in flat glass and container glass products. The percentages shown represent an average of many companies7 specifications.

Jan 1, 1994

By C. L. Sainsbury

For 10 years, the author has been engaged in a program of geologic mapping of the Seward Peninsula, Alaska, for the U.S. Geological Survey. Initially, two 1:63,360-scale quadrangles were napped by traditional methods of traverses by foot and by tracked vehicle, supplemented by reconnaissance from a light aircraft owned and piloted by the author. Five summers were required to map those two quadrangles, which lie north of the tree lice in typical Arctic climate. In 1967, the project was reoriented toward the reconnaissance capping of four 1:250,000-scale quadrangles, with helicopter support to be used for cart of each of four summers amounting to about 45 hours time per support year. The light aircraft was use-,' to support the field operations. Over the year,, the aircraft was used in progressively more geologic tasks, culminating in 1970 with a successful field test of rudimentary devices made to collect soil, rock, and sediment samples while the aircraft remained airborne. Additionally, an attempt was made j- 1970 to prepare reconnaissance geologic maps entirely by the use of the light aircraft combined with foot traverses [fr??], the landed aircraft. Several such maps, prepared at the rate of about one 1:63,360-scale quadrangle per day, were checked from a helicopter by an impartial observer end were found to be sufficiently accurate for reconnaissance mapping when reduced to 1:250.000 scale.

Jan 1, 1971

By Manuel Diaz del Rio

At the present time there are over 5,000 Kms of railway tunnels in existence throughout the world. In many cases these tunnels were built over a century ago using techniques obsolete today. Supervision and maintenance of these tunnels is essential to the economy of each country involved. For this purpose an electro-optical measuring system has been designed incorporating highly complex soft and hardware (15 mW laser, high resolution TV camera and processing computer), mounted on a vehicle. Its job is to scan, record and compare sectional gauge values (profiles) and strains inside tunnels both momentarily in situ and on permanent record, as an aid to the supervision work. From the state of the strains observed, in conjunction with an infrared spectrum of the tunnel lining and soil involved, the mechanical stresses in the tunnel can be deduced by applying the boundary elements method.

Jan 1, 1981

By Thomas E. Newman

This paper is a case study using new laser-terrain-mapping technology by EagleScan, Inc., for creating topographic maps. Holnam, Inc., has used this technology to create maps and volumetric calculations of several mines in the United States. The information is superior to conventional methods through accuracy, manpower, time, and cost. Holnam, Inc., was the first cement manufacturer to use the Digital Airborne Topographic Imaging System (DATIS?). The technology uses the DATIS? to produce high-resolution terrain maps and volumetric assessments of any area. DATIS? is a mapping instrument that integrates (1) a Light Detection and Ranging (LIDAR) instrument to measure terrain elevation using laser light, (2) a large-format digital camera, (3) a relative position Global Positioning System (GPS) to measure aircraft position, and (4) an Inertial Measurement Unit (IMU) to measure aircraft attitude. The DATIS? can measure up to 220,000 elevation samples per mil. The system continually collects data on the aircraft's position and measures the time for each laser pulse transmission to return from the ground, giving each sample a GPS reference. The system can operate at night, in overcast sky, and during high-wind conditions and can measure terrain below vegetation cover, unlike standard aerial photography used for traditional surveying and mapping. Surveyed ground-control panels are no longer necessary with this new technology, and only one ground GPS base station located within 60 mi from the aircraft position is required. A computer elevation-point data file is created with the x, y, z coordinates of each laser elevation sample. With this file, CAD engineering programs can create topographic maps that rival products using conventional aerial mapping techniques. Volumetric measurements of stockpiles and pits are also available due to the high density of points collected from an area. This new technology radically changes the turnaround time for map users, giving a product in the format used by today's cartographers. The time line from flight to maps is measured in days instead of weeks.

Jan 1, 1999

By J. Hazen, R. Jenner

This project was developed at the PCS Phosphate Mine in Aurora, NC. This site includes a surface mining operation, beneficiation plant and chemical processing facility located in the coastal plain of eastern North Carolina. The phosphate ore being mined at this operation is a 10 to 12 meter (35 to 40 foot) thick colloidal deposit located approximately 30 meters (100 feet) below the ground surface. The ore is pumped to the beneficiation facility where it is separated into clay, sand and concentrate streams. The concentrate product is utilized at the chemical plants to produce a wide range of products including fertilizer, industrial phosphates and animal feed products. The Cyclone Dike Builder (CDB) project developed a technique for dewatering the beneficiation tailing sand stream and providing innovative placement for dike construction. Future material balance requirements at the PCS Phosphate mine required an improvement in tailing sand placement technique to accomplish strategic objectives. The water volume of the sand slurry forces significant quantities of sand out of the dike profile during deposition. PCS Phosphate and MetPro Supply of Florida developed a mobile high-density hydro-cyclone station to remove most of the water and significantly increase the density of the sand being placed for dike construction. This high-density sand slurry is then effectively controlled using minimal heavy equipment operation.

Jan 1, 2004

By T. W. Meikle

Three nutrient amendments and a biological seed inoculant were evaluated for use in establishing vegetative cover on waste rock substrates. Randomized blocks were placed on three substrates. Treatments included two types of organic fertilizer, mineral fertilizer, Azospirillum bacterial inoculant, plus controls. The seed mix consisted of native grass species adapted to low nutrient conditions. Canopy cover has been monitored for three growing seasons. Results indicate: 1) two of three substrates support plant growth following amendment with organic fertilizers; 2) organic fertilizers increase cover substantially over mineral fertilizer; and 3) Azospirillum had no effect on canopy cover.

Jan 1, 1999

By D. C. Yang

A packed column jig has been developed for sharp separation of fine particles--150 down to 1 micron--having different densities. The packed jig is a column filled with corrugated packing. A slurry of mixed particles is fed into the middle of the column. Water enters near the bottom of the column as both a steady state and a pulsating flow. The pulsating water sets up a jigging action that interacts with the packing causing the dense particles to sink and exit the bottom of the jig and the lighter particles to rise and exit the top of the packed jig. The result is a sharp, environmentally friendly, gravity separation machine with low operating costs. Grades and recoveries of iron ore exceed that of known devices. Grades as high as 95 percent purity with concomitantly high recoveries are common for iron ore concentration. Low silica, sulfur and phosphate are common. This paper is the first to unveil the packed column jig technology in detail and presents its physical model with performance data. The purification of iron ores and coal is the paper's focus.

Jan 1, 1997

By J. R. England, W. J. Taylor

The Sudbury Basin is the scene of the mining operations of the Ontario Division of the International Nickel Company of Canada, Limited. Around the rim of the geological formation and within thirty miles of the City of Sudbury are located twelve operating mines and one open pit operated by the Company. The City, with a metropolitan population of some 100,000 lies 240 miles Northwest of Toronto. In addition, there is one mine in Northwestern Ontario, at Shebandowan, 700 miles Northwest of Sudbury. In 1973 these mines produced 16.5 million short tons of ore of which 14.9 million tons were from underground and the balance from open pit operations. Mining methods include blasthole, sublevel caving, induced caving, shrinkage, cut-and-fill and undercut-and-fill. Raise boring commenced at Inco in 1964 and is now applied at all mines in the Sudbury District (Figure 1). [ ]

Jan 1, 1974

By R. B. Krog

Airflow patterns in longwall bleeder systems are affected by gob permeability and porosity and the condition of the gateroad entries after mining. As longwall panels are mined, areas of the caved zone and portions of the remaining gateroad entries become inaccessible, making direct ventilation measurement impossible. Mine operators are left to estimate direction and amount of airflow in the gob and the surrounding gateroads. The most readily available locations are where air enters the worked-out area, approved measurement point locations (MPLs) and/or evaluation points such as bleeder evaluation points, intake evaluation points, and the outer bleeder entry. Ventilation models (network or Computational Fluid Dynamics, CFD) can model the gob and the surrounding bleeder system but calibrating these models is difficult without field data. NIOSH installed a tube sampling system ahead of a longwall face and, as the face retreated, released a slug of tracer gas (SF6) to determine transportation times and flow rates in the inaccessible gateroads. The data was used to calibrate both network and CFD ventilation models for a longwall panel. Both model types were used to predict the airflow patterns in the gob and to determine the airflow rate from the longwall tailgate corner back to the bleeders.

Jan 1, 2011