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

7. Hoisting Systems Hoists used solely for emergency escape use should above all, be simple and dependable. The hoist systems' motive power should be independent of all other mine equipment so that only an emergency in the immediate vicinity of the hoist will render it inoperative. The hoist should receive the same high level of inspection as is normal with any other man hoisting system. It should be operated at regular intervals, and must include sufficient safety devices to ensure safe operation when hoisting men. Of equal importance, however, safety devices must be included to safeguard the hoist system from in¬advertant damage due to inspection, maintenance or operator error In an emergency situation the hoist operator will be under considerable stress and the system must be simple and foolproof to operate. Under normal circumstances the hoist will only be operated during the regular inspection cycle. Because of this very low operational use rate, certain requirements, normally associated with man hoisting, can be relaxed. In particular the wire rope installation requirements, in terms of drum and sheave diameter and fleet angles, can be reduced provided that rope inspection during the system life is maintained at a high level. The following section includes recommended guidelines for emergency hoist system design, installation, operation, maintenance and inspection A summary of available hoisting equipment and components is included in Appendix C. Emergency Hoist Guidelines All hoists designated as part of a mine emergency escape system shall meet the requirements of the Emergency Hoist Guidelines. Where these hoists are also utilized for hoisting other than emergency hoisting, the requirements of Title 30, Code of

Jan 1, 1976

By Oliver Bowles

"A New Mica Company in China A report has been received from the American Consulate at Chungking, China, to the affect that a new company has been organized to operate a mica mine north of Ta-chien-lu, in the province of Ssu-Chuan. The company, which is entirely under Chinese management and control, has a working capital of $10,000. While comparatively new, the mine has been worked before, and apparently with some success. The mica is said to be of good quality. It is claimed that the deposit will supply a limited amount of mica that will cut in pieces a foot square or over, and larger quantities of smaller sizes. The chief difficulty is transportation, for it is reported that a ten days' journey, part of it over mountain trails, will be necessary to transport the mica from the mine to Yachow, the nearest practical waterway. It is probable, therefore, that the output of the mine will be limited.Necessity for Careful Trimming and Grading of MicaA recent report to the Department of Trade and Commerce, Ottawa, Canada, by Acting Trade Commissioner C. G. Venus, London, England, contains information which is of vital interest to mica producers in the United States. It is pointed out that mica exports from Canada to England show a gradual decline dur¬ing recent years, the figures being as follows: 1913- 1,383 cwt: 1914 - 1,225 cwt: 1915 - 1,864 cwt: 1S16 - 879 cwt: 1917 444 cwt: 1918 - 480 cwt. Shipments from India to England, on the other hand, show a steady increase from 40,178 cwt. in 1913 to 66,401 cwt, in 1918."

Jan 1, 1920

By D. J. Parker

State governments are increasing their efforts each year toward promoting the safety of miners .. Accidents underground are being avoided and mines made safer by means of revising and adding to their mining laws , by enforcing them through mine inspection departments , and by hearty co - operation with other agencies working miners ' safety . The U. S. Bureau of Mines is glad to testify to the co -operation that it receives from State mining departments in its safety work ; reports of the field mining engineers of the Bureau bear witness almost daily to the efforts of the States toward safety in mining . * This Through the courtesy of Mr. William Ogilvie , District State Wine Inspector of District No. 2 , with headquarters at "cAlester , Oklahoma, the Bureau has been furnished with a copy of a letter sent to various mining companies of Mr. Ogilvie's district in Oklahoma, relative to safety in Oklahoma mines . letter shows both the vigorous efforts which the State of Oklahoma is making toward increased safety in mines , and the recognized value of the types of electric cap lamps approved by the U. S. Bureau of Mines as " permissible " for use in gaseous mines ; it is accordingly reproduced in part : "hen during my first inspections of several coal mines in the district I found gas , or fire- darp being given off more or less constantly from the freshly cut coal at numerous points throughout the mines , I became uneasy relative to safety conditions , and am still considering your safety from many angles , but I am more concerned about the gas given off and the coal dust produced daily, than any other factor at the present time .

Jun 1, 1922

By Oliver Bowles

It is noteworthy that 80 to 95 per cent of the gross production of all slate quarries in the United States is discarded as waste . In view of the loss involved in handling so much waste , and the consequent added cost of the finished product , the Bureau of Mines has undertaken a study of the slate industry for the purpose of devising the best means of reducing the proportion of waste , and of utilizing the unavoidable waste . The utilization of waste has received special attention , and the cooperation of many prospective purchasers of waste slate has been enlisted in testing its adaptability for various uses .

Mar 1, 1921

By Lloyd A. Morley, Robert Stefanko

Table

Jan 1, 1974

By Roy C. Bartholomae

An accurate characterization of the vibration environment and a vibration qualification test derived from it will be a very useful tool for manufacturers of instrumentation for use on underground coal mining equipment. Recognizing this, the Bureau of Mines sponsored a study wherein vibration levels were measured on mining equipment to form a basis for developing the required vibration test. The data base was composed of 160 samples taken at different positions on a variety of underground machinery. The data were analyzed and presented in a format typical of military vibration qualification tests. The form was shown to be virtually identical to the swept sine test envelope specified in MIL-STD-810B for tracked vehicles.

Jan 1, 1982

By Paul M. Linebarger

This paper is one of a series of digests of foreign mining legislation and court decisions prepared in advance of a general report relative to the rights of American citizens to explore for minerals and to own and operate mines in various foreign countries. This interpretation of the laws of Mexico has been pro oared from the best information available in Washington but is released subject to correction and amplification, if necessary, by the proper American diplomatic and consular officers, to whom it has been referred through the courtesy of the Department of State. INTRODUCTION Present-day Mexican mining legislation involves, not only the latest minim enactment (August 1, 1026), but many other enactments and regulations, principal among which are the Constitution, the Civil Code, the Code of Commerce, the Foreign Law, the Mining Tax Law, and. the Civil Jurisprudence of Mexico--the last-mentioned being based in Dart on Supreme Court decisions. Ere Mexican Federal Government is supreme in mining legislation because, among other reasons, a large part of the revenue of the Government must come from the fiscal control of the mines. All circulars, decrees, and rulings that affect the mines not only have their origin in the Central Government but are administered thereby. The Department of Industry, Commerce, and Labor is in control of all mines. Attention may here be called, however,

Jan 1, 1929

By P. C. Good

The work reported here was undertaken by the Federal Bureau of Mines to investigate new methods of preparing high-purity metal. Tungsten hexachloride was prepared by direct chlorination of scrap tungsten metal and by treating tungstic oxide with carbon and chlorine. The resulting tungsten hexachloride was purified by distillation and reduced win: sodium, magnesium, or hydrogen. The metal prepared by these techniques was at very high purity after arc melting but of variable quality prior to arc meIting. Metal recovery ranged from about 40 to 90 percent of theoretical values, It was found possible to deposit a smooth, dense coating of high-purity tungsten on the inside of a heated tube by vapor-phase reduction of tungsten hexachloride at reduced pressure.

Jan 1, 1961

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 D. B. Dow

"In the natural-gas Gasoline industry, the methods used in determining the amount of gasoline in natural gas are many and varied; they include the specific-gravity test, laboratory tests involving absorption, charge in volume of the gas or in the absorption medium, absorption in charcoal with subsequent distillation, compression of the gas which results in the condensation of the gasoline, and the absorption of the gasoline vapors in an absorption oil, from which the gasoline is distilled and measured. Each of these various tests has advantages, and disadvantages. It is however, conceded in the industry that the tests in which the gasoline is obtained and measured as such are the more reliable.This paper deals with certain factors which should be considered in making absorption tests using ""mineral seal oil"" as an absorbent; this method of testing is widely used not only in the field, but in control work in absorption gasoline plants where the gasoline content of the intake and discharge gas is determined daily. In control work it is frequently found that the plant produces more gasoline than the tests show, which gives the plant the appearance of making more gasoline than is actually present in the gas treated, or in other words operating at more than one hundred per cent efficiency. Obviously then, the tests as made in these cases are in error, and in hope of correcting some of these variances, the following factors have been studied at the U. S. Bureau of Mines petroleum station at Bartlesville, Oklahoma."

Aug 1, 1920

By John L. Ellenberger

The Bureau of Mines investigated the occurrence of slickensides in mine roof in the Pittsburgh coalbed in a portion of the Valley Camp No.3 mine in southwestern Pennsylvania to improve the potential for prediction of slicken-sided zones and determine the orientations of the most prominent slickensided planes. Two distinct types of slickensides were identified; those which were associated with clay veins observed in the coalbed (genetic), and those which were unrelated to any visible structure (nongenetic). The study draws three conclusions: (1) Nongenetic slickensides are not the result of tectonic forces, (2) both genetic and nongenetic slickensides tend to dip at an angle of 30°, and (3) genetic slickensides tend to be alined parallel to the trend of the clay vein and usually dip toward the center of the clay vein. A schematic roof bolting plan is presented that may provide improved roof support where slickensides are present. Roof stability could be improved by supplemental bolting in the direction normal to the plane of slickensides.

Jan 1, 1979

By James E. Hill

The Bureau of Mines has been carrying on an extensive diamond- drilling program during the past 7 years on deposits of strategic and critical minerals . Often the project reports and the drill-hole logs describe the findings only in terms of the mineral being sought at the time . Then , too , results may not always be interpreted alike by several mining engineers , and the cores therefore provide a permanent tangible record to complement the project reports . The cores from projects in the eastern divisions are being stored at the Mount Weather Testing Adit . Core from a representative hole ( or skeletonized sections from several holes , if these are more representative ) is selected at each project and shipped to Mount Weather for permanent storage . At the Testing Adit an underground room was prepared and storage racks were installed . Wooden core trays designed to accommodate cores of various sizes were purchased .

Apr 1, 1947

By A. B. Hooker

Investigations at the Pittsburgh Experiment Station have shown that the satisfactory operation of a flame safety lamp depends not only upon proper design and assembly of the lamp but upon the kind of fuel used, and that much of the trouble experienced with permissible flame safety lamps at mines is due to the common use of motor gasolines, none of which is suitable in the present types of permissible flame safety lamps. This report gives the results of a limited study to determine what satisfactory fuels are available, the specification limits of such fuels, and to suggest modifications of assembly and care of the lamps to improve performance with any satisfactory fuel.

Jan 1, 1938

By A. D. Garman

This paper presents one of a series of digests of foreign mining legislation and court decisions which is being prepared in advance of a general report relative to the right of American citizens to explore for minerals and to own and operate mines in various foreign countries . This interpretation of the laws of Nicaragua has been prepared from the best available information in Washington , but is released subject to correction and amplification , if necessary, by the proper American diplomatic and consular officers to whom it is being referred through the courtesy of the Department of State .

Jul 1, 1930

By H. G. Lucas

A feeder screw supplied at constant pressure by a hopper-orifice arrangement was developed for feeding solids in size ranges up to several hundred micrometers at constant flow rates. Performance of the feeder was evaluated by measuring the flow rates obtained with 3-to 7-micrometer coal ash, 70 percent through 200-mesh coal, and minus 325-plus 400-mesh coal ash. Constant feed rates within a few percent of set values were achieved for half-hour periods for the larger particles and for 5-minute periods for the finer particles. Suggestions are given for feedstock preparation and feeder operation for optimum performance.

Jan 1, 1974

By H. S. Chiang, S. S. Peng

"SummaryAir velocity distribution surveys on four mechanized longwall faces are presented and discussed. Although there are discernible patterns in the velocity distribution, there are wide differences in distribution in the cases examined. This can be attributed to differences in mining and face geometry. An important factor is air leakage into the goaf.IntroductionOver the past two years several intensive air velocity surveys have been carried out in West Virginia coal mines as part of a programme aimed at understanding dust transport mechanisms on mechanized longwall faces. These are presented here and some of the patterns of velocity distribution are discussed.Ventilation survey methodologyThe air velocity vector consists of three mutually perpendicular subvectors; the vertical subvector is directed toward the roof, one of the horizontal subvectors is parallel to the coal face and the other pointing to the gob. The air velocity which was measured in this paper is the horizontal subvector parallel to the coal face.To record the velocity distributions at the longwall faces, the surveying stations and the surveying points were established as follows.(1) The first station usually was set at the third support from the headentry T-junction. Within the first few supports, the air coming from the intake airway encounters a sharp right-angle turn at the T-junction, and forms a turbulent region close to the coal face. The intake air in this region is also influenced by the motors that drive the face conveyer. But when the air reaches the different. But for the same face the number was the same. The main air-travelling area was divided into six to 12 equally sized sub-areas, and each surveying point was situated approximately at the centre of the sub-area.The velocity survey was carried out by two persons, one reading the meter and the other taking down the readings. A complete survey at one station took about 5-8 min. Usually, the dimension of the cross-sectional area was measured during that time.A third person used the smoke tubes to observe the following: (I) the air movement patterns at different locations; (2) the extent and the direction of the air leakage; and (3) the machines' influence on the main airflow. At the same time he observed and recorded the roof conditions and the compactness of the roof-caving in the gob."

Mar 1, 1989

By P. M. Gruzensky

In view of some of the outstanding properties of chromium, considerable effort has been made in recent years to prepare the high-purity metal in ductile form. The object of this investigation was to obtain such metal by electrolysis of chromic acid solutions and to determine the conditions that yield optimum results. The apparatus is described, as well as the parameters that received consideration. Ion-exchange resins were employed to remove cation impurities from the electrolyte. Tensile specimens prepared from the electrodeposits by arc melting, press forging, swaging, and drawing, were ductile at room temperature. INTRODUCTION Metallic chromium displays an exceptionally high resistance to corrosion, oxidation, and wear at elevated temperatures. Although these properties are utilized to some extent when chromium is alloyed with other metals, such as in stainless steels, high-chromium alloys and pure chromium are not employed as engineering materials because of a serious lack of ductility and impact resistance at room temperature. Because high-chromium alloys appear promising as refractory metals for applications such as in gas turbines, much interest has been shown recently in the preparation of uniformly ductile chromium and in determining which factors contribute to its brittleness.

Jan 1, 1957

By E. J. Matson

The Little Castle Creek chromite deposit was examined in February and May 1941, respectively, by W. O. Vandenburg and O. H. Metzger, engineers of the Bureau of Mines. The Federal Geological Survey started a magnetometer survey of the area in November 1940 and completed its work during April and May 1941. Field work by the Bureau of Mines was conducted during May and June 1941. The purpose of the Bureau of Mines investigation was to search for a continuation of the chromite mineralization. The property at one time was the largest chromite producer in California.

Jan 1, 1949

By BUREAU OF MINES

The cheapest method of handling gravel in placer mining operations is by hydraulic mining . In working gravel deposits by hydraulic mining , it is essential that an abundant supply of water under sufficient head can be economically developed and that there is sufficient grade for sluice boxes and for disposal of the tailing . Without dumping facilities , simple hydraulic mining is an impossibility . The cost of hydraulic mining may range from 2 cents a yard under favorable condıtions to 12 or even 20 cents under less favorable conditions and to 35 cents or more a yard in Alaska , according to conditions of operation , and if frozen gravel is encountered . When it is necessary to elevate gravel , the costs may exceed 60 cents a cubic yard . When the natural conditions do not permit of hydraulic pining proper , other methods of elevating the grade are employed , some of which are described below . Bucket dredging has replaced hydraulic mining in importance in California and other states where hydraulic mining was once extensively carried on , and is by far the cheapest method of elevating gravel when mechanical methods are required and the physical conditions are suitable for dredging . Dredging costs vary greatly under the different conditions encountered , and the total amount of gold to be recovered must of course be enough to warrant the cost of a dredge installation . Gold dredging operations in the United States are fully described in Bull . 127 , U.S. Bureau of Mines .

Jan 1, 1922

The results of a Feasibility and Design Study of Surface Impregnation Equipment to be used for Chemical Stabilization of Coal Mine Structures are described in this report. The study was sponsored by the United States Department of the Interior, Bureau of Mines, under Contract H0210055. This program was undertaken as an essential part of the Bureau of Mines Chemical Ground Stabilization Program. The responsible prime contractor was The Eimco Tunneling and Mining Machinery Division of the Envirotech Corporation. The Rocketdyne Division of the North American Rockwell Corporation performed part of the feasibility study and design and testing of the metering and feed system as a subcontractor to Eimco.

Jan 1, 1972