Search Documents

1. Mining to prevent and control underground acid formation should begin with education imparted through: (A) Course work at mining schools to teach prospective engineers. (B) Training of engineers presently employed in the mining industry through appropriate mining extension courses. 2. Considerable need exists to devote more attention to: (A) Hydrogeologic studies of mining areas to enhance the planning of new mines and the abatement program of existing mines. (B) Additional research to explore methods of dewatering the strata associated with mining areas. (C) Further effort to develop sealants for preventing contact between water or oxygen and the acid producing material associated with the coal seam.

Jan 1, 1970

In 2006, a total of 741 nonmetal mining operations reported employment to the Mine Safety and Health Administration (MSHA).1 These mines (e.g., potash, gypsum, salt) comprised 5.0% of all operations. ? Mines producing common clay comprised 25.2% (n=187) of all nonmetal mining operations. ? Nonmetal mining operations were located in all states and territories except Alaska, Delaware, Hawaii, Maine, New Hampshire, Rhode Island, Puerto Rico, and the Virgin Islands.

Jan 1, 2008

Table 1.-Employment and injury experience at metal mines in the United States, by industry groups [ ]

Jan 1, 1967

By David A. Monaghan, Kenneth R. Maser, Adi R. Gurdar, D. Randolph Berry

APPENDIX C SCALING RELATIONSHIPS 1. Scaling Law for Fly Ash Crater Formation The scaling law derived for predicting crater diameters at different scales is developed below by considering the equation of motion of individual fly ash particles. It is assumed that the air drag on each particle is characterized by Stokes flow, and at the borehole - passage intersection the air velocity and the fly ash particle velocity are the same. The equations of motion for a fly ash particle are the following, (see Figure C-1).

Jan 1, 1973

1. In 2002, a total of 2,065 coal mining operations reported employment to the Mine Safety and Health Administration (MSHA). Coal mines comprised 14.2% of all mining operations. • Bituminous mines comprised 92.5% (n = 1,910) and anthracite mines 7.5% (n = 155) of coal mining operations. • More than 70% of all coal mines were located in three states: Kentucky (28.7%), West Virginia (21.7%), and Pennsylvania (20.1%).

Jan 1, 2004

By S. Gallagher, A. Mayton, R. Merkel

The prolonged exposure of equipment operators to shock and whole-body vibration (WBV) IS linked to cumulative back, neck, and abdominal disorders. In low-coal mines, space restrictions make seat suspensions difficult to use in isolating operators from shock and WBV. Researchers at NIOSH, Pittsburgh Research Laboratory, are responding to these issues by investigating viscoelastic foams. For the full-load case. an ergonomic seat with viscoelastic foams isolated the shuttle car operator from shock at 15 Hz. Researchers used results from additional foam testing with an analytical model to identify viscoelastic foams that provide shock isolation at a frequency below 5 Hz.

By David Hoadley, Kenneth R. Maser, Ashok B. Boghani, James E. Billar, D. Randolph Berry, Mackenzie Burnett, Robert H. Trent

C.5 Safety Equipment and Control Devices Safety equipment and control devices serve two principal functions in mine escape hoists. First, they can be used to provide important safety features such as protection against overspeed, over¬travel and undertravel. Second they can be used to automate or partially automate the operation of the escape hoist. Typical equipment available is described in the following section. 1. Simplex and Lilly Hoist Controllers Manufacturers: Logan Actuator Co. 4956 No. Elston Ave. Chicago, Illinois 60630 312-736-7500 The Simplex and Lilly Controllers provide a means for electrically shutting off the power to the hoist and the energy to physically set the brakes in the event of overspeed, overtravel, undertravel and failure to begin deceleration within sufficient distance

Jan 1, 1976

By R. H. Grau, S. B. Robertson, F. Garcia, A. C. Smith, T. P. Mucho

Researchers working for the National Institute for Occupational Safety and Health (NIOSH) at the Pittsburgh Research Center are developing ways to protect the health of miners. Part of that effort is improving the air quality in metal/nonmetal mines by developing proper ventilation techniques. The air quality of large opening nonmetal mines can be greatly improved by using engineering controls of contaminant prevention and proper ventilation techniques. Contaminant prevention includes methods to reduce contaminants from entering the mine air. Ventilation can be improved with appropriate fan selection and fan operation used in conjunction with air coursing using manmade and insitu rock stoppings.

By David Hoadley, Kenneth R. Maser, Ashok B. Boghani, James E. Billar, D. Randolph Berry, Mackenzie Burnett, Robert H. Trent

The computer program has been developed in conjunction with the rest of the project to evaluate evacuation capabilities of the mines and develop guidelines for the escape systems. There are several problems associated with predicting evacuation performance of a mine. First, the mine has many interconnected passages, shafts, hoists and a number of miners in varying positions. To be able to predict evacuation time requires processing a hugh amount of data. A simplistic approach of determining the miner farthest from the exit and calculating evacuation time for him knowing his walking speeds and hoisting times is not realistic, since the waiting time for the hoist is neglected. The second problem is being able to repeat the calculations for a number of configurations. It may be possible to spend enough time to hand calculate the evacuation parameters for a single mine for a single configuration, but to evaluate capabilities of the evacuation

Jan 1, 1976

By Fred Turin, Kim Cornelius, Lisa Steiner

NIOSH researchers have been examining underground coal mining activities in order to evaluate work crew hazards. In 1994 a continuous mining machine operator was killed by falling roof during extended cut mining. Many aspects of the incident were used by NIOSH researchers to develop a scenario interview. The goal was to provide a realistic framework for acquiring frank and detailed insights. The interview consists of two sections. The first describes the underground mining conditions. The second recounts the fatal incident. Each section is supplemented by a diagram and a set of questions addressing relevant safety issues. The interview was administered at three mines that actively take extended cuts. Researchers found the scenario approach to be an effective interview tool as well as an effective hazard awareness and safe work practices training platform.

By Arthur E. Goddard

Radio propagation measurements were conducted in a coal mine at UHF (200 to 1000 MHz) and VLF (1 to 50 kHz) to characterize the transmission loss of intra-mine paths. The basic experimental parameters included frequency, polarization, path orientation and distance. Further tests evaluated the performance of roof-bolt vs. loop antennas at VLF and parasitic reflectors at UHF. Measurement results are summarized in a series of transmission loss curves. Examples are presented to show the use of these curves in predicting the performance of radio communication systems in mines.

Jan 1, 1973

By Julie Mitchell, Robert King, Len Eros

The Bureau of Mines has studied the Deserado Mine computerized monitoring and control system, located in Rangely, Colorado, to acquire knowledge about the overall costs and benefits of mine monitoring systems. The Deserado system is a complex system monitoring environmental parameters, electrical power, and operation of all mine equipment, and controlling the entire conveyor haul age system. This paper discusses the evaluation of the Deserado monitoring system from initial design through system installation and operation. It also examines the costs, benefits, and performance of the monitoring system.

By David Hoadley, Kenneth R. Maser, Ashok B. Boghani, James E. Billar, D. Randolph Berry, Mackenzie Burnett, Robert H. Trent

APPENDIX C - HOISTING SYSTEMS - AVAILABLE EQUIPMENT C 1 - Introduction A survey has been made of available hoisting equipment which has applications for use in metal and non-metal mine emergency escape hoist systems. The information was gathered from a number of sources, including representatives in the USBM and MESA, mine operators, personal visits and telephone interviews with manufacturers, field visits to inspect equipment, advertisements, catalogues and indices of manufacturers. Wherever possible, technical specifications and prices were checked out with the manufacturer, or supplier. The sections on individual sub-systems and components, such as automatic control systems, winches and controls, are not intended to be all encompassing surveys. Rather a reasonable number of representative units in each category are discussed. The sample is large enough to provide a general picture of the kind of equipment available, including the abilities and limitations and a reasonable price range. The survey has been divided into six categories 1. Complete Hoisting Systems A Above ground installations B Below ground installations 2. Hoist Assemblies ^(Man-rated) 3. Hoists (not Man-rated)

Jan 1, 1976

By A. Dale Marcy, Pamela L. Drake

Workers who perform routine welding tasks are potentially exposed to fume that may contain manganese. Manganese may cause respiratory problems and is implicated in causing the occurrence of Parkinson-like symptoms. In this study, a field colorimetric method for extracting and measuring manganese in welding fume was developed. The method uses ultrasonic extraction with an acidic hydrogen peroxide solution to extract welding fume collected on polyvinyl chloride filters. Commercially available pre-packaged reagents are used to produce a colored solution, created by a reaction of manganese(II) with 1-(2-pyridylazo)-2-naphthol. Absorbance measurements are then made using a portable spectrophotometer. The method detection limit and limit of quantification (LOQ) were 5.2 mg filter-1 and 17 mg filter-1, respectively, with a dynamic range up to 400 mg filter-1. When the results are above the LOQ for the colorimetric method, the manganese masses are equivalent to those measured by the International Organization for Standardization Method 15202-2, which employs a strong acid digestion and analysis using inductively coupled plasma-optical emission spectrometry.

By C. P. Lazzara, R. A. Franks, G. F. Friel, J. C. Edwards, J. J. Opferman

A fire detection research program conducted at the National Institute for Occupational Safety and Health (NIOSH) Pittsburgh Research Laboratory (PRL) recently demonstrated the advantage of multiple fire sensors for early fire detec¬tion and nuisance alarm discrimination in underground coal mines. As an example, research has shown that an appropriate combination of smoke, CO, and metal oxide semiconductor (MOS) sensors has the capa¬bility to detect a smoldering conveyor belt fire which produces low visibility due to smoke, but CO concentrations too low for an early fire alarm. Such a sensor combina¬tion has the additional advantage of being able to distinguish a nuisance alarm event such as those produced by diesel engines or acetylene torches from mine fire products¬-of-combustion (POC) produced by a real tire. Research has also shown that the problem of hydrogen (H2) gas cross-interference with chemical CO sensors at battery-charging operations in diesel-emissions backgrounds can be resolved with a smoke sensor and a MOS sensor sensitive to NOx associated with diesel emissions. Other underground conditions, such as rock dust, exacerbate the problems with sensors. NIOSH has developed a neural network that takes many of these variables into account as it assesses real-time sensor data to discriminate nuisance alarms.

By Doris M. Hyde

Belize remained relatively insulated from the social and political turmoil that affected some of its Central American neighbors. This stability encouraged new foreign investments that assisted the economy, especially in tourism and agriculture. The mineral sector remained limited to construction-oriented materials. Oil exploration efforts continued by the various concessionaires.

Jan 1, 1987

To inexpensively monitor the ventilating airflow anywhere in underground working places. The Approach: The Bureau has developed a small self-contained monitor which sounds an audible alarm and energizes a flashing lamp if air velocity decreases below normal. How It Works: The sensing element of this inexpensive monitor is a thermistor, which is self-heated by a constant-current electrical source. Airflow over the thermistor increases heat removal and lowers the thermistor temperature. Since the electrical resistance of a thermistor is a function of temperature change, the voltage across it varies with temperature, and, therefore, the air velocity. Changes in the voltage across the thermistor are amplified, and can be used to trigger the alarms.

Jan 1, 1975

By Marc T. Filigenzi

Two of the major ground control safety issues confronting underground mine operations today are shaft pillar stability and the failure of rock around active mine openings. Failure of a mine shaft can lead to the entrapment of workers. Failure of rock around active underground mine openings can lead to roof falls, which in turn can result in worker injuries and fatalities. Finite-element analysis has proven to be a reliable method for predicting stresses and displacements around underground mine openings. However, this is a complex and time-consuming technique and is not used as often as it could be in mine planning. The purpose of this paper is to demonstrate one technique developed at the Spokane Research Center that allows the user to create a finite-element model of a two-dimensional section of an underground mine in a relatively straightforward manner. This model is then used to calculate stresses, displacements, and safety factors around mine openings. With this information, mine planers can evaluate the stability of mine openings as well as the stability of pillars and mine shafts. This analysis will help develop mining sequences and layouts that minimize stresses in that section of the mine. This, in turn, should minimize the occurrence of shaft failure, roof falls, and other hazards associated with underground mining.

The generally disappointing results obtained in the present study, together with the high material costs involved, preclude any general recommendation for a continuation of the work. One recommendation arises, however, from some observations on the application of latex to spoil banks. It was found that dilute latex used on a slope of spoil bank material at an application rate of 400 lbs per acre (dry basis) stabilized the soil and made it much more resistant to washout by rainfall. It is recommended that a study be conducted to use latex for temporary stabilization and/or sealing of spoil banks before and during reclamation procedures, on coal slurry ponds and coal refuse piles.

Jan 1, 1972

By R. V. Ramani, P. M. T. White, D. Sutton

6.1 Summary This report deals with the investigation carried out to select, test, and implement a method of evaluating coal deposits and reserves. Cognizance is taken of the inherent characteristics of coal and the legislation covering aspects of health, safety, environment, and ecology applicable to the coal mining industry. Further, the method is computerized and provides information that is meaningful and readily available to other programs and sub¬systems within the concept of the Master Design Simulator. The Geology and Reserves Sub-system interface with the total system is provided by a geological data library which is structured to hold and make accessible all the data required by the system. The output from the program is accurate and useful to users with a wide variety of computer experience, knowledge, hardware and storage capacity. The sub-system is designed to function as a separate unit or an integral part of the total system and, there¬fore, an interface to or with the system has been established. The work carried out by the sub-system includes: (a) The analysis of raw geological data. This involves:

Jan 1, 1974