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By D. Harrington, M. W. Von Bernewitz

Sections 120 and 121 of Article XI. Fire Control, of a proposed Mine Safety Law in preparation, to be used as desired and when approved by any State, contains these provisions: After the adoption of these regulations, no mine operator shall erect any nonfireproof structure within 50 feet of any mine entrance. or airway. Every operating mine having nonfireproof structures within 50 feet of any mine entrance or airway, except headframes necessary for hoisting, shall have such structures fireproofed or removed and replaced with fireproof structures within six months of the adoption of these regulations. Before reopening, mines idle at the time of the adoption of these regulations shall have all non- fireproof structures fireproofed, removed, or replaced with fire- proof structures as required by the foregoing sentence. Upon receipt of the written statement of a mine operator that the fireproofing of existing structures is impracticable, the chief mining engineer (of the State commission) shall satisfy himself as to the abouracy of the statement. If he concurs that fireproofing is impracticable, and if at the same time he holds the opinion that adequate protection can be provided otherwise by such procedure, he shall have authority to issue a written permit for the substitution of fireproof door at or near portals of mine openings and collars: of shafts. Such doors shall fit as nearly gas-tight as possible. and shall be installed in such a way that the mouths of mine open- ings can be closed readily from outside of structures. The effec- tiveness of such permit may be made contingent upon the operator's continued compliance with any additional precautions which are necessary in the chief mining engineer's opinion to protect the lives of miners.

Mar 1, 1932

By Henry M. Harris

The Bureau of Mines investigated a glass containing approximately 17 percent lithia and 83 percent silica to establish a method of devitrifying cast and rolled shapes. Glass shapes with high strength were made by melting, forming, and rapid cooling of the composition, and the shapes subsequently were converted to a crystalline condition by heat treatment. The best devitrification schedule included rapid cooling of the glass to below 300° C, followed by reheating at a rate of 50° to 400° C per hour, depending on the size of the shape, followed by a of 60 to 70 hours at 500° C and another period of 15 hours at 800° C. attempts to use faster heating rates or slow cooling to accomplish devitrification in deformation of the shapes. The crystalline shapes had flexural strengths that averaged over 33,000 psi, achieved with an annealing time of 60 to 70 hours at 500° C.

Jan 1, 1965

By J. E. Tiffany, Gaigler. Z. C.

"PREFACEIn presenting this list of permissible explosives and blasting devices, the Bureau of Mines desires to call attention to pages 16 and 21 outlining the conditions in use under which, and only under which, the explosive or blasting device is permissible.In view of a recent publication recounting trade practice favoring the use of a blasting device without stemming, particular emphasis is placed upon condition 4 on page 16 and condition 2 on page 21. An explosive or a blasting device enumerated in the permissible lists of this Bureau is not permissible in use unless it is properly confined with clay or other incombustible stemming.PERMISSIBLE EXPLOSIVES TESTED UNDER SCHEDULE 17CAn active list of permissible explosives was published in December 1937 as part of Bureau of Mines Report of Investigations 3361, under the title ""Active List of Permissible Explosives and Blasting Devices Approved Prior to June 30, 1937.n This list included 196 brand names.Changes in the list that have been authorized to June 30, 1938, placed 7 additional brands of permissible explosives on the active permissible list as a result of tests, changes in brand names, or transfer from the inactive list. Twelve permissible explosives were transferred from the active to the inactive list. The present list contains 191 brand names. The brand names of the permissible explosives placed on the active list are as follows:"

Oct 1, 1938

By W. E. Miller, Kennedy. R. E., G. W. Jones

"INTRODUCTION Ethyl mercaptan (CH3,CH2SH), a combustible organic liquid of the thioalcohol type, is employed at an odorant in many types of fuel gases and dangerous atmospheres, which in themselves are devoid of characteristic odors, to give warring against leakage of such gases or atmospheres into places where they might constitute health or explosion hazards.Ethyl mercaptan has a penetrating disagreeable odor resembling that of onions, garlic, hydrogen sulfide, or rotting cabbage, that exceedingly low concentrations of it can be detected. The of odorants as a beans of detecting leakage of gases and atmospheres has been investigated extensively by chemists and engineers of the Bureau of Mines, and numerous reports as to its value have been published."

Jun 1, 1942

By Richard L. Rains

During this study in 1983, the U.S. Bureau of Mines examined one mine and five prospects in the Greenwater Valley Wilderness Study Area (WSA). No mineral resources were identified within the WSA. Principal mineral commodities in the WSA are gold and silver with minor lead, and zinc. Two properties have significance; sample analyses indicate the Salsberry Prospect may have gold-silver-lead-zinc resources, and the Graham Jem Mine may have gold resources. The likelihood for development is greatest at the Salsberry Prospect, although the only recorded production from the study area was from the Graham Jem Mine; in 1908 less than 1 ton of gold-bearing ore valued at $25,000 per ton was produced. Gold, silver, lead, zinc, and copper minerals in the WSA are associated with rhyolite dikes and quartz veins in Precambrian gneissic rocks, commonly concentrated in sheared zones along the dikes and veins. Although known to contain silver-lead deposits elsewhere, Precambrian Noonday Dolomite sampled inside the WSA contained no significant mineral values. Much of the WSA is covered by relatively unmineralized Tertiary and Quaternary volcanic rocks. The Bureau collected 140 rock samples at four adits, nine shafts, four trenches, and 33 prospect pits in the WSA. In 1983, 14 lone claims and one millsite within the study area were current. No patented claims, placer claims, or coal, mineral, oil and gas, or geothermal leases were in the WSA.

Jan 1, 1985

By Ronald A. Vary

This paper is one of a series prepared by the United States Bureau of Mines dealing with milling methods and costs. In view of the current revival of interest in gold mining, information dealing with practices and costs in the development of gold properties is apropos. Milling practice at a small gold property in the prospect stage is described where, with a small outlay for plant and equipment, development has been carried on for about 20 months on the proceeds of the mill operation with little additional expenditure. The paper shows about what may be expected as to costs at a small property operated under northern climatic conditions and with rigid economy throughout the plant.

Jan 1, 1931

By John C. Gagliardi

The size and complexity of modern surface haulage trucks has resulted in an increased reliance upon sensors and electronic-based instrumentation for safe and efficient operation. Design engineers need accurate information about the equipment vibration environment to efficiently and effectively build components for installation on mobile mining equipment capable of withstanding the mine environment. Examples of such components include backup alarms, communication equipment, microprocessor-based controllers, and a wide variety of sensors. Unfortunately, this information is not available to the majority of both original equipment and aftermarket equipment manufacturers. To address this problem, the U.S. Bureau of Mines performed field vibration measurements on a variety of surface mining haulage trucks. The vibration measurements were then analyzed and test specifications were developed in the form of envelopes. In conjunction with test specifications, recommendations to aid manufacturers in implementing a vibration environment test program have been included with an illustrative example.

Jan 1, 2010

By Charles L. Harness, A. T. Coons

Sodium carbonate, Na2CO3, more commonly known as soda ash, is the most important of the alkalies. Sulfuric acid is the only heavy chemical, Soda ash enters the market either as the natural product or as a manufactured derivative of common salt. Notwithstanding their common occurrence in closed basins of the Western States, natural sodas are produced at present by only four firms, all in the same California area, and satisfy only 4 percent of domestic demand for soda ash; soda ash made from salt supplies 96 percent of the requirements. The impossibility in wartime of routing all westbound American shipping through the Panama Cami.l has curtailed Pacific Coast receipts of soda ash and-increased the importance of local resources of natural carbonates. One of the most promising of ·these is the recently discovered trona (sodium sesquicarbonate)· deposit 2o·mnes· west of Green River, Wyo. Reserves are likely to run into hundreds ·of million·s of tons, and the deposit probably could be worked by the room-and~pillar· system of mining, like common salt or coal. • • Raw materials ·ne·cessary for manufacturing synthetic soda ash occur closely associated in m·afiy parts· bf the United 8tates. Almost unlimited resources of salt in brines and in rock-salt depbsits are located near limestone quarries in many areas. The· limesto'ne furnishes the carbon dioxide for the manufacture of soda ash arid the lime f o'r the recovery of ammonia. used in one step of the process. Expansion of the industry to meet wartime needs depends chiefly on availability of trained labor, materials, and equipment necessary for the erection of additional units.

Jun 1, 1942

By Harold J. Barnett

In January 1948 , the Secretary of the Interior directed that a study be made of energy resources and requirements that would provide a basis for continuing appraisal of the adequacy of the Department's programs in the energy field . That this instruction was timely has been demonstrated by the increasing interest being evidenced by Congress , industry , labor , and the public in the future of the energy segment of our national economy . Several studies of individual energy sectors have appeared . Various legislative proposals have been made in Congress for obtaining more information on this subject . Substantial interest in energy projections is not , of course , a recent innovation . Energy availability and consumption are strategic factors in peacetime prosperity and growth and in our national defense as well . The past generation's literature of earnest public discussion and of legislative consideration of matters involving energy projections is very extensive . This is an exploratory study produced in the Program Staff of the Office of the Secretary of the Interior in the first half of 1949 and revised recently to take account of certain of the preliminary energy data from the 1947 Census of Manufactures and critical comments . It is offered at this time solely as a technical contribution in economic research technique . As the Bureau of Mines has recently undertaken to revise this preliminary study , critical and other comments are invited .

Oct 1, 1950

By Thomas Mucho, Anthony Iannacchione

This marks the 100th year that the aggregate industry has been served by a national association. Of all the accomplishments this longstanding relationship has achieved, there is probably none greater than the progress made, in worker safety. Perhaps the best way to measure this success is to examine injury trends in the aggregate miner population. For example, in the first half of the 20th [ ] century, 16 quarry mining disasters (a "disaster" is an incident with five or more fatalities) claimed 157 miners between 1909 and 1952. The largest of these was the disaster at the Sandts Eddy Limestone Quarry near Allentown, Pa., on March 26, 1942, where 31 miners died of asphyxiation by fumes/explosion. Thankfully, no mining disasters have occurred in the aggregate industry since 1952. It is these kinds of information that help us characterize improvements in aggregate worker safety over the last 100 years.

Jan 1, 2003

By Lulie H. Crump

Salient historical data on consumption of fuels and energy have been summarized by State and census district for the years 1960 through 1972. This Information Circular covers States east of the Mississippi, and Information Circular 8705 covers States west of the Mississippi. These data replace previously published compilations of energy consumption statistics by States and districts. Future annual studies are planned using the same Btu conversion factors applied in these two. Information Circulars.

Jan 1, 1976

By Maria I. De Rosa

The U.S. Bureau of Mines conducted a study to determine if correlations exist between the chlorine or nitrogen contents of materials and the hydrogen chloride (HCI) or hydrogen cyanide (HCN) concentrations evolved during the thermal decomposition of these materials. Hydrogen chloride, hydrogen cyanide, and carbon monoxide (CO) were found to be the primary toxic gases evolved during the combustion process. The experiments were carried out in a 20-L furnace with 1-g samples. The furnace temperature, rising from ambient, was set at 1,000 °C with an airflow of 10 L/min. The variables measured were the gas loads (milligrams per gram) of HCI, HCN, CO, and CO2 (carbon dioxide); CO and CO2 concentrations as a function of time were also measured. Other variables included the average concentrations of submicrometer smoke particles and particles' average diameter, mass of particulates, sample and furnace temperatures, and sample weight loss. The data indicate that there are significant correlations between the percentage of chlorine or nitrogen contained in the original samples and the HC1 or HCN concentrations evolved during the combustion of the materials. These correlations may be used to predict and evaluate a material's toxic hazard during combustion.

Jan 1, 2010

By Thomas J. Peters

The Lime Creek study area lies 100 air km east of Boise, and 70 air km northeast of Mountain Home, Idaho. The eastern boundary of the 28,000-hectare, east-west-elongate study area lies 0.2 km west of the 3,077-m-high Smoky Dome. The area is mainly underlain by Cretaceous granitoid rocks of the Idaho batholith. No mineral resources were identified, but two mines and one prospect were found in the study area. At the President and the Last Chance mines, in the southwest corner of the study area, gold mineralization occurs along steeply dipping east-northeast-trending faults and associated quartz veins, and within adjacent Cretaceous granitic rock. The mineralized material is not rich enough to mine underground, and near surface, open-pit-mineable deposit areas could not be identified. The third prospect, the Ventura, is within altered pink granite of probable Tertiary age, but metal concentrations are very low. Geothermal activity was not observed within the study area, but hot springs do occur in the Vicinity. Bedrock observed is only suitable for the most basic high bulk and low end value applications, such as crushed aggregate. Numerous sources for crushed stone occur closer to markets. Alluvial concentrate (placer) samples did not contain free gold, and no substantial alluvial bars were seen; deposits were too small to contain resources.

Jan 1, 1993

By Philip W. Holland

The U.S. Bureau of Mines has designed and built an inexpensive, weatherproof, temperature-controlled cabinet to provide temporary housing for analytical instrumentation. The cabinet consists of an inverted Styrofoam ice chest, an electric fan for air circulation, and a proportional temperature controller equipped with a thermistor sensor and a light bulb as the heater. The cabinet provides a constant-temperature environment for a moisture analyzer and a strip chart recorder when outside temperatures range from -SO to 21° c.

Jan 1, 1993

By M. J. Ankeny

The expression "firing open, unconfined shots," as used in this circular, means the firing of explosive charges not confined in boreholes. Examples are the so-called mudcap shots, adobe or dobe shots, or bulldozing shots consisting of explosive charges placed on, under, or between rocks for the purpose of breaking them. The practice of firing open, unconfined shots is not uncommon in coal mines, despite the fact that numerous mine explosions and dust ignitions have resulted from this practice. The usual method of preparing such shots is to place the explosive with its detonator on top of a piece of rock or coal and cover it with clay, loam, sand, or road dust; frequently no covering of any kind is used. In some mines, an open charge of explosive is placed on timbers to dislodge them or in crevices in the roof to break down loose rock that cannot be dislodged with a bar or pick. The explosive charges may be made and fired singly, although sometimes several charges are placed on one large piece of rock with a detonator in each charge, and all charges are fired simultaneously. Although it is general practice to use permissible shot-firing devices, which will not ignite gas or dust to fire these charges, electric power from the regular mine circuits is sometimes used. When the shot is fired, any coal dust that may be present is thrown into suspension by the blast and may be ignited by the intense hot flame of the explosive or by an arc or spark at the leg wires or the end of the firing leads if power from the regular mine circuit is used to fire the shot. Even if there is not enough coal dust present to form a dust cloud, open, unconfined shots can readily ignite methane.

Jan 1, 1952

By R. D. Currie

Many coal companies have a system for checking men into and out of the mine , and generally such systems appear to be perfectly sound and adequate . However , when the real test comes at the time of a mine disaster , too often the system is found to have failed , and hours and sometimes days pass before it is known how many men are in the mine and who they are . Most of the systems in use , when properly maintained , are adequate for the routine work of the mine , and some of them may prove adequate at the time of a mine disaster . All systems , however , depend upon proper supervision and strict adherence to the system .

Jun 1, 1930

By D. J. Singleton

Erosion corrosion of 12 alloys in phosphoric acid waste water was studied by the Bureau of Mines. Tests were conducted on oblate spheroids or cylindrical specimens in 12-and 60-cm-diam ball mills by grinding phosphate rock in gypsum pond water with a starting pH of 1.6. For comparison, tests were conducted while grinding phosphate rock in plain water. Static corrosion tests in gypsum pond water also were conducted. For all alloys, the wear by erosion-corrosion (milling with gypsum pond water) was greater than the sum of erosion (milling with water) plus static corrosion. Erosion-corrosion wear was about 1,500 to 3,000 mpy for the alloyed white cast irons, 1,000 to 1,400 mpy for commercial steel ball material and type 316 stainless steel, and 600 to 900 mpy for nickel-base alloys and a high-manganese, nitrided stainless steel. Alloy costs per unit of phosphate rock 'processed favor a low-alloy, high-carbon steel or a high-manganese, nitrided stainless steel.

Jan 1, 1985

By Oliver W. Keener

The operation described herein differs from the usual practice in the Tri-State district in two important respects: (1) the ore is loaded into cars which are tramped to the shaft and hoisted on self-dumping cages, and (2) about 30 per cent of the ore is loaded by power shovels. The four-month period covered by the cost data appended at the end of the paper immediately followed a period of about one year during which the mine was shut down, and the expense incident to the resumption of operations is reflected in the costs. The author acknowledges the assistance of C. F. Jackson, mining engineer, U. S. Bureau of Mines, in the preparation of this paper and the compilation of the data.

Jan 1, 1929

By J. F. Barkley

[There 1 s [\ general conce:!?t in the coal trade tha t the ;noi sture-and ash-free B. t.'I. of coal from t.he oome seam, and surely from the same mine, is substantially a cor.stant: that calculatio!: of the ::1oisture-and ash-free B. t. u. value f~~oJl t he proxima te ru:al~rsi sand. 3. t. u. determined in tl19 laboratory 111ill reveal v:?letller a coal came f~'om a. given : area or seam; and that, having this constant, the 3.t.u. value of a coal sample can be c lculatcd fairl...' closely 11:0on a? dry or as~received basis from the r.lois]

Jan 1, 1941

By Alla D. Mah

Combustion energies of barium and strontium were measured by means of the combustion bomb calorimeter. The heats of formation obtained for the oxides were ?H298.15 = -139,060 ± 700 cal/mole of barium oxide (BaO) and ?H298.15 = -144,440 ± 400 cal/mole of strontium oxide (SrO). Tables containing heats and free energies of formation from 298.15° to 2,000° K were prepared.

Jan 1, 1963