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By C. R. Kindall

Recently 30 men wore viewing the demonstration of a now portable electric arc-welding outfit. A few hours later 17 of the 30 men reported to the doctor for treatment. They were suffering from traumatic conjunctivitis. In two cases the gain was very severe and the symptoms were similar to those of iritis. orphine had to be administered to afford relief from pain. Only two men of the 30 wera not affected in some way from this exposure. These two men were thick-lensed orange-colored glasses. Several of the men wore orange-colored glasses with thin lenses, but the latter were not heavy enough to afford protection.against an exposure as long as took place. The distance of the eye from the are also in- fluences the possibility of injury. Conjunctivitis is an inflammation of the con- junctiva; the conjunctiva is the mucous membrane covering the inside of the eye- lids and part of the eyeball. Traumatic conjunctivitis is caused by foreign bodies in the eye, exposure of the eyes to high winds, dust, smoke, intense light from electric arc lamps, and from electric welding apparatus. In the instance mentioned above, the inflammation was due to the ultra-violet rays. The ultra-violet rays lie beyond the violet rays in the spectrum and are invisible to the eye. In some cases the effect is so severe that, in addition to conjunctivitis, an inflammation of the skin similar to sunburn is produced. The symptons of conjunctivitis caused by intense light or by the ultra- violet rays are marked photophobia (abnormal intolerance to light), excessive secretion of tears, intense starting of the lid, contraction of the pupil, some- times swelling of the lid, and small ulcers developing on the eyeball or cornea. Unless properly treated by a physician immediately, chronic inflammation of the conjunctiva, cornea, iris, or retina, and possibly blindness, may result. Under proper treatment most cases get wall in a few days. All treatments should be under the direction of a physician. That usually advised is to place ice packs on the patient's eyes three or four times daily. The pack should be left on from 15 minutes to an hour. The eyes should be irrigated with normal salt solution (a teaspoonful to a quart of sterile vater) or a saturated solution of boric acid several times daily. If there is a discharge of pus, a few drops of a 25 per cent solution of argyrol or a 5 per cent solution of protargol should bo placed in the eyes three to six times daily. The patient should be confined to a darkened room until his condition improves in order to avoid complications. These treatments will reduce the swelling, give the patient confort, and prevent the development of chronic conjunctivitis. In severe cases it may be necessary to administer morphine to relieve the pain.

Oct 1, 1920

By John Nagy

This circular has been prepared for the guidance of safety engineers, shot firers, and coal-mine inspectors concerning multiple blasting with short-delay (millisecond-delay) detonators. These special precautions are suggested in addition to those normally followed in blasting, as outlined in the Federal Mine Safety Codes 5 6/ and in Miners' Circular 58.7/ INTRODUCTION The use of short-delay blasting has been proposed for promoting safety and increasing the rate of production in coal mining. Ideally, short-delay blasting, as compared with equivalent single-shot blasting, reduces exposure of the shot firer to dust, fumes, and weakened roof; as compared with equivalent simultaneous blasting, it reduces roof disturbance.

Jan 1, 1959

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

C 2 Complete Hoisting Systems A Above Ground Installations A total of seven companies were identified who supply complete emergency escape hoist units for above ground installations The units have been designed predominately to meet the needs of coal mine operators to satisfy the requirements of the Coal Mine Health and Safety Act of 1969. The seven companies are as follows 1 Dover Conveyor and Equipment Co. 2. Coeur d' Alenes Co. 3. Connellsville Corp. 4. Scott Midland 5. W W Williams Co. 6. Equipment Corporation of America 7. Timberland Ellicott Table VIII contains detailed specifications and price information on each of these units. The units have a number of similarities

Jan 1, 1976

By John P. Gooch

Data for the ternary phase diagram for the system 1,1,2,2-tetrabromoethane/water/2-propanol at 25° C have been measured. Experimental methods used are described, and the complete ternary phase diagram is presented. A simple example is given to review the use of the ternary diagram.

Jan 1, 1972

By Fred N. Kissell, R. J. Bielicki

In this report the importance of diffusion in controlling the emission of methane in mines is examined. An in-situ diffusion parameter is defined and calculated for a hypothetical unfractured lump of coal in the Pittsburgh and Pocahontas No. 3 coalbeds. The values obtained are similar to those obtained with lump coal in laboratory experiments.

Jan 1, 1972

Allow miners to communicate via the pagerphone system when they are not near one of the phones. Approach A small lightweight pagerphone, having crocodile clips which pierce the phone line insulation, was developed. How It Works The Portable Telephone/Intercom is temporarily clipped onto an existing pagerphone line at any location, and operated like an intercom. It is riot necessary to strip the insulation from the pagerphone line to make the connection. In addition to the clips for connecting to pagerphone line, the Portable Telephone/Intercom consists of a small belt-carried control box, an ear-phone, and a bone-conduction microphone which is attached to the webbing in a miner's helmet. All together, these components weigh only 20 ounces including the batteries

Jan 1, 1977

By Richard L. Lewis

This is a discussion of the application of the zonal harmonic series to problems involving dipole sources in the vicinity of spherical boundaries. The application of a formal zonal-harmonic series solution to directly obtain numerical results involves two distinct problems: namely, the convergence of the series solution and the accurate calculation of the special functions involved in the series solution. Some interesting techniques will be introduced which help to improve the convergence properties of the series solution.

Jan 1, 1973

Table B-1. Summary of respirable coal mine dust samples collected under 30 CFR 90 by MSHA inspectors for underground occupations, 1988-92* [ ]

Jan 1, 1997

By Todd M. Ruff

A training software package for new mine employees, called Miner Training Simulator (MTS), has been developed by researchers at the National Institute for Occupational Safety and Health. MTS is a computer-based tool that allows a trainee to enter a simulated mine and interact with his/her surroundings in order to learn basic mining concepts, safety procedures, mine layouts, and escape routes. The training simulator software and instructions for its use are described in this report. Also, each mine using the software will have different requirements with regard to safety training. To customize the simulator for these differences, an interpreted scripting language is used to define interactions between the trainee and the virtual mine and objects in it. The scripting language, called Tool Command Language, uses simple commands to control various actions in the simulation, such as sounds, safety messages, hazards, and movement of objects. The basics of the scripting language are described here, along with many examples and instructions for building a script for MTS.

Jan 6, 2001

By Gordon L. Kinney

Following a year of great uncertainty, the political situation in Bangladesh improved during 1976. The major problem for Bangladesh remained the high birth rate and crowded conditions. Bangladesh had the highest population density of any agrarian country--over 80 million people in a land area of 144,000 square kilometers, 65% of which is considered arable. The Government, with considerable foreign assistance, was actively encouraging voluntary family planning, and set a growth rate target of 2% per year or less. However, even if the growth rate was reduced to the target level immediately, the population of Bangladesh would nevertheless nearly double within 20 years.

Jan 1, 1980

By T. O. Llewellyn

Laboratory batch and semicontinuous studies showed the feasibility of using methylene bromide and trichloroethylene in heavy liquid cyclone concentration of a Nevada brucite ore. Cyclone tests of minus 20- plus 200-mesh material at specific gravities of 2.42 and 2.44 recovered 71.6 to 74.9 percent of the MgO at grades of 95.5 and 95.4, respectively. Neither increasing the feed pulp density from 5 to 25 percent solids, nor varying feed pressures from 25 to 60 psig had any apparent effect on the heavy liquid separation.

Jan 1, 1971

By R. V. Ramani, R. Stefanko, G. W. Luxbacher

1 14 THIS IS A DIGITAL COMPUTER SIMULATION OF THE VENTILATION SYSTEM OF A MINE LOCATED IN WASHINGTON COUNTY, PENNSYLVANIA. THE VENTILATION SURVEY ON WHICH THIS SIMULATION IS BASED WAS RUN FROM OCT. 27-30 AND ON NOV. 2, 1976 IN THE ACTIVE PORTION OF THE MINE INBY COMBS SHAFT AND THE INACTIVE PORTION AFOUND AND INBY DONAHOO SHAFT. FOLLOW-UP SURVEYS WERE THEN RUN ON FEB. 18 AND FROM MARCH 7-11, 1977 TO INCLUDE THE MAIN HAULAGE SYSTEM OUTBY THE ACTIVE AREAS OF THE MINE. ALL SURVEY DATA WAS NORMALIZED TO A STANDARD DENSITY OF 0.075 POUNDS/CU.FT. PRIOR TO THE CALCULATION OF INPUT PARAMETERS FOR THIS SIMULATION. IN THIS RUN, THE ORIGINAL VENTILATION NETWORK HAS BEEN MODIFIED TO INCLUDE NEW INTAKE AND RETURN AIRSHAFTS AT THE WEST MAINS. IN ADDITION A CONNECTION HAS BEEN MADE BETWEEN THE MINE UNDER STUDY AND A SHAFT IN A WORKED OUT MINE IN THE 1 FACE AREA. THIS SHAFT IS CONSIDERED AN INTAKE SHAFT FOR THIS RUN.

Jan 1, 1977

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

4. Preliminary Study - Remote Seal Checker 4.1 Introduction Determination of the completeness of each individual seal at the time of its emplacement is essential for an effective remote sealing system. A satisfactory seal checking technique should provide a signal which: (1) indicates percentage completion as the seal is emplaced (2) provides a definite indication of a complete seal (3) indicates the size of the unsealed area if a complete seal is not feasible This information is required to establish the need for additional seal material, the need for additional seals, and the risk likely involved in entering the mine., In many situations it is as important to know the quality of a seal as it is to build an effective one. It is likely that with repeated use the remote sealing technique developed by Foster-Miller Associates will be sufficiently reliable and predictable to preclude the seal checking requirement. It is recommended, however, that each seal be checked during construction to insure its completeness and increase the level of confidence so necessary in reopening the mine. 4.2 Description of General Problem Several characteristics of remote mine seals are important in considering techniques for evaluating the effectiveness of these seals. These include:

Jan 1, 1973

To improve mining safety and efficiency by providing a practical way of detecting faults and channel sands that disturb coal seams. Approach A seismic system using a shallow blasthole has been developed and tested. How It Works A small shock is caused in a shallow hole, sending seismic waves through the ground. These waves are reflected from the top of the coal seam, acid are detected by a line of geophones on the earth's surface. Dampening of the seismic signals by channel sands and other discontinuities in the seam is detected and recorded. See Figure 1. The seismic shock wave can be produced by exploding small charges, dropping a weight, firing a gas gun, or actuating a vibrator. Depending on the soil cover, the shock is usually generated in shallow vertical holes about 10 feet deep. Hole depth depends on the soil mantle thickness because it is preferable that the seismic shock originate below that layer.

Jan 1, 1976

To reduce front-end loader (FEL) collision accidents by detecting obstacles in the rear blind area. The Problem Federal regulations require an audible backup alarm to activate when an FEL is backing. Since the device is constantly being activated, the warning soon becomes a normal part of the mine environment and is less effective as a warning device. Also, when several machines are working together, it is difficult to detect by ear alone just which machine is backing. Approach The Bureau defined the location for hazard detection to include an area extending 15 to 20 ft behind the rear bumper of an FEL. Then, existing surveillance and detection technology was assembled, ruggedness, and applied to the FEL's rear blind area to form a new discriminating backup alarm system employing either infrared light, ultrasonics or radar

Jan 1, 1986

Reduce the time, complexity and expense of dissolving metal and mineral samples in solution in preparation for chemical analysis. Approach In earlier research, the Bureau of Mines developed a rapid and inexpensive method for the dissolution of mineral and metal samples in plastic pressure bottles heated in a boiling water bath. Using this technique, samples could be prepared for chemical analysis in less than one hour compared with several hours by traditional dissolution methods (see Technology News No. 85, December 1980 for further details). By heating in a microwave oven, sample dissolution time can be reduced to approximately 5 minutes.

Jan 1, 1983

By Nancy S. Raymon

The Bureau of Mines investigated the effect of controlled additions of selected metal oxides, as well as the adjustment of the calcia-to-silica ratio on the high-temperature strength of refractory-grade periclase. Increases in the hot flexural strength of some periclase materials in the range of threefold to fourfold were obtained with additions of Zr02 and by adjustment of the CaO:Si02 ratio to the 2.5 to 3.0 level. Results show that for each periclase refractory raw material, there exists a combination of level of Zr02 addition and an adjustment to the CaO:Si02 ratio that optimizes the hot flexural strength of each of these materials. Data also indicate that the improved hot strengths can be attributed to the high-temperature secondary phases formed between the different levels of periclase impurities and the additives, resulting in improved intergranular high-temperature bond strength.

Jan 1, 1982

By B. J. Scheiner

Silver ores from the Candelaria District, Nevada, and Round Mountain District, Colorado, were investigated mineralogically and metallurgically. Silver minerals of four distinct groups were identified: (1) silver sulfide; (2) argentojarosite; (3) silver contained in the iron oxide; and (4) manganese carbonate-oxide minerals, Electrooxidation and acid-chloride leaching techniques were investigated as means of altering silver minerals, and their effects on subsequent silver extraction were determined. Application of the knowledge obtained from mineral leaching studies resulted in development of a sulfur dioxide-sodium chloride leaching sequence for extracting silver from these types of ores. Silver extractions of 80 to 85 percent were obtained by leaching the ores with a sulfurous acid-sodium chloride system. This was an increase of 9 to 61 percent silver extraction over that obtained by conventional cyanidation techniques.

Jan 1, 1973

Improve transmission of data from an underground mine monitoring system to a remote, mass-data storage system. Background Instrumentation systems in underground mines must operate under environmental extremes of dust and humidity, local electromagnetic/radio frequency (EM/RF) interference fields, and potentially explosive atmospheres. During a recent roof-bolt study performed by the Bureau of Mines, it was necessary to transmit a large quantity of data to a data storage system. Conventional wire cable transmission presented several limitations which often required special electrical isolation or physical protection. Because conventional wire cable presented certain problems, the Bureau of Mines investigated alternative means of data transmission. The research investigation led to the selection of fiber optic cable for data transmission applications. The fiber optic method of data transmission offers several advantages: ? Since the transmission medium consists of light waves, it is safe to use in gassy mines. Where applicable, MSHA permissibility standards for peripheral devices must be met. ? It is lightweight and rugged. ? It can operate up to 131000 feet (4km) without repeaters and without EM/RF field interference.

Jan 1, 1986

Simplify the spraying of sealants onto coal mine roofs. Approach A nonclogging system in which dry-fed sealant is mixed with water down-stream of the spray nozzle, has been developed and tested. How It Works The two-channel nozzle of this spray discharges two separate flows, a mixture of air and dry sealant from a central cylinder, and an encircling spray of water from a concentrically mounted water ring (a ring-shaped manifold). Downstream of the nozzle, the water mixes with the air and sealant to form a wet sealant spray that adheres to mine surfaces with very little rebound. (See photograph.) Extensively modified commercial spray machines are used to feed the sealant to the spray nozzle smoothly, without raising dust. Plugging of the nozzle is practically eliminated by two self-cleaning design features of the nozzle. These are the air gap and the tapered bore of the cylinder, (See drawing.)

Jan 1, 1979