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By John C. Holtz

"INTRODUCTION Information on the gaseous products from the detonation of explosives has been obtained in two ways. In the first, the atmosphere in mines is analyzed after blasting, and in the second, the gases found after detonating an explosive in a testing apparatus are analyzed. The Bureau of Mines, in a cooperative research 3/ that compared data obtained in the field with those obtained in the testing station, showed that the results were not in entire agreement. The production of carbon monoxide was found to be governed chiefly by the oxygen balance of the explosive, but the production of oxides of nitrogen did not change in so simple a manner. Because of the increasing interest in correlations between the composition of the explosive and the production of toxic gases, it seemed desirable to continue the investigation.PURPOSE OF INVESTIGATIONAs field tests are both time consuming and expensive and as field results are affected by factors that are not always under control of or clearly evaluated by the operator, the purpose of this investigation is to develop a testing-station procedure that will reproduce the gaseous products quantitatively under known conditions analogous to those that may be expected in the field. In addition, the factors affecting the formation of toxic gases, particularly oxides of nitrogen, will be studied,"

Apr 1, 1940

By James Paone

This report shows the feasibility of predicting drillability, analytically, by using regression analysis techniques. The approach is new in diamond-drilling research. Further, the study shows that this technique may be of value to drill manufacturers and others in mathematically delineating performance characteristics of new drills in specific rock types. Another application might be the prediction of penetration speeds in extraterrestrial material based on the physical properties of the materials as samples become available. Prediction equations for penetration rates are presented for 9 rocks drilled in the laboratory and for 20 rocks drilled under field conditions. The prediction equations are based on drill operating parameters and on characteristics of the rock penetrated. No single physical property appeared consistently in the best predictor equations, and all the physical properties were found to be highly correlated with each other.

Jan 1, 1966

By Frank J. Wiebelt, Spangler Hicker

The Iron Mountain investigations were part of a comprehensive program for making a national inventory of raw materials used in the production of steel. A tentative program of core drilling by the Bureau of Mines was set up for exploration of more promising iron deposits. Iron Mountain was selected as worthy of investigation because it could serve as a potential source of ore for the war-created steel plant at Fontana, Calif. The deposits were reported on by an engineer in October 1943. The purpose of the project was to determine the lateral and vertical extent of ore bodies and to obtain accurate material data on them.

Apr 1, 1948

These inspection standard have been prepared for use in the Federal inspection of strip mines producing, bituminous coal, anthracite, and lignite. This circular is a revision of the Safety Code for Strip Mining, which was prepared by the Bureau of Mines and employed as a guide for Federal inspectors. Numerous changes have been made in the original code to keep the in step with improvements in the industry. With continuing changes in mining methods and facilities some of these standards may become inapplicable and further revision may be advisable. Therefore, questions regarding these standards, and suggestions regarding new standards should be brought to the attention of the Bureau of Mines. Few States haves laws pertaining to strip mines, but where such laws do exist it is possible that some of the standards may conflict with them. In cases of conflict, the intent is not to advocate noncompliance with State laws, but to suggest reconsideration of such laws or safety orders.

Jan 1, 1946

By D. A. Hill

This volume contains a summary of the results of past analyses on U.S. Bureau of Mines Contract No. H0122061 which are relevant to electromagnetic location in mine rescue situations. The analytical results indicated that detection of a trapped miner equipped with a special transmitter is feasible in most situations. Location of the miner by surface measurements is also generally feasible within certain errors. The feasibility of miner detection and the accuracy of miner location have been examined theoretically for a wide variety of situations. Agreement with experimental results is generally good in cases where measurements are available.

By Henry E. Perlee

In a Bureau of Mines study two-dimensional mathematical equations were solved that describe the transient thermal response of a rock dust particle in a cloud of similar particles in a gas flame's preheat zone subject to a radiant field from the approaching flame. The description includes both radiant energy absorbed and emitted by the particle and thermal conduction inside the particle and into the surrounding gas environment moving relative to the particle. Two situations were studied; in one the radiant energy incident on the particle is converted to thermal energy at the particle surface, and in the other the radiant energy is converted to thermal energy uniformly over the volume of the particle. The result of the study showed that for a 10-µm-radius particle, a 200-mg 1-1 loading density, and a flame approach velocity of 30 m sec-1, the particle temperature rise was twice that previously calculated by Singer and Cook based on the model of Essenhigh and Csaba. It was further established that under the conditions examined a rock dust particle temperature never increases more than about 200 K before crossing the flame front.

Jan 1, 1976

By G. L. Oldright

In the previous study that has been made by the authors on smelting in the lead blast furnace,4 the furnace examined was one that operated under conditions that have been considered as more or less normal up to the present time. That is, although the furnace had in its charge a large portion of sinter, it also handled considerable quantities of naturally oxidized direct-smelting ore. Other ingredients, such as the limestone, were also added as fairly coarse material. The charges contained only about 24 per cent of lead. Until the changes incident to modern flotation began to take effect, many lead plants doing semicustom smelting in districts where competition was keen and much of the bonanza ore was exhausted were faced with the difficulty of obtaining enough lead to get a sufficient "lead fall" in the blast furnaces to clean the slag thoroughly and to separate it from the lead. A charge containing 24 per cent of lead would have been considered a very rich one by such smelters.

Jan 1, 1931

By G. L. Oldright

In the previous study that has been made by the authors on smelting in the lead blast furnace, the furnace examined was one that operated under conditions that have been considered as more or less normal up to the present time. That is although the furnace had in its charge a large portion of sinter, it also handled considerable quantities of naturally oxidized direct-smelting ore. Other ingredients, such as the limestone, were also added as fairly coarse material. The charges contained only about 24 per cent of lead. Until the changes incident to modern flotation began to take effect, many lead plants doing semicustom smelting in districts where competition was keen and much of the bonanza ore was exhausted were faced with the difficulty of obtaining enough lead to get a sufficient "lead fall" in the blast furnaces to clean the slag thoroughly and to separate it from the lead. A charge containing 24 per cent of lead would have been considered a very rich one by such smelters.

Jan 1, 1931

By William P. Diamond

This report presents results of a cooperative research project between the U.S. Bureau of Mines and BethEnergy Mines, Inc. Four coreholes (two before mining and two after mining) were drilled at a longwall mine operating in the Lower Kittanning Coalbed to obtain coal and rock samples from over-lying strata to determine their gas content at various times in the mining cycle. The results of those tests indicate that 91 pct of the gas removed from the overlying strata came from coalbeds. Material balance calculations were made to compare the volume of gas produced both from gob gas vent holes drilled on the panel and gas removed by the mine's ventilation system with the volume of gas removed from strata directly overlying the panel to a height of 275 ft. This analysis indicates that only 40 pct of the total gas produced from the panel actually came from the strata directly overlying the panel. The remaining volume of gas production probably migrated to the longwall gob from overlying, and perhaps underlying, strata immediately adjacent to the panel and perhaps from greater distances downdip because of the establishment of a long-term pressure gradient in the study area.

Jan 1, 2010

By Louis C. Brichta

The Kline tract ?3.nd the Frey tract are two separate properties situated in the Wentworth district on the easterly edge of the Tri-State zinc-lead region (fig. 1). The Kline tract is in the southwestern corner of Lawrence County, Mo., and the Frey tract, 1 1/2 miles west of the Kline, is in the northeastern part of Newton County, Mo. A bureau Of Mines drilling project embraced work on both properties, but the amount of work done on the Frey tract was comparatively small. At the time of the project the Kline tract was under lease to the Wentworth Mining & Milling Co. The Surprise Mining Co. held the lease on the Frey tract. Underground workings on the generally flat-bedded are deposits of the Kline property-covered an area of-about 15 acres. No total metal-production records are available. In 1942-1943 the mine, operated by the Wentworth Mining & Milling Co., produced at an average monthly rate of 83 tons of 60-percent zinc concentrate derived from mining and milling 1,700 to 2,100 tons of ore. At the end of that period no significant amount of reserve ore was in sight. The gravity-flotation mill on the property was operating at about one-sixth capacity.

Jan 1, 1949

By Carl Belser

This paper, covering Chaffee, Fremont, Gunnison, Lake, Larimer, Park, and Summit Counties, Colo., is the second of a series reporting on the tungsten potential of the Colorado region. The assembled information was obtained by examination of some properties, personal contacts with owners, and access to unpublished reports by other engineers. The tungsten-bearing areas of the 7 counties cover approximately 400 square miles and are in 10 distinct areas, which vary in size (fig. 1) from 1 square mile up to 290 square miles. The tungsten mineral wolframite was discovered by a man named Hackay near Dale on the Florence & Cripple Creek Railroad in the early 1900's, and wolframite and hubnerite were noted at Climax and the adjacent areas in Lake and Summit Counties at an early date, but no records of shipment from any of the areas are available before World War II. It is not known when scheelite was first discovered, but it was recognized in the Stockton mine during World War I. In the counties listed 64 properties are known to contain tungsten; of these, 18 have had some commercial output, although only 3 of them produced in 1953. The total production through 1953 is estimated at 115,000 short-ton units of tungsten trioxide. In 1953 by far the major portion came from the Climax mine.

Jan 1, 1956

By Howard E. Rollman

South Central United States, an area including Arkansas, Kansas, Louisiana, Mississippi, Missouri, Oklahoma, and Texas, is a net exporter of refractories. Nearly $45 million of these materials was shipped in 1954 from plants in the area, compared with area consumption of $18.5 million. About 88 percent of all refractories production is concentrated in Missouri. The prevalent consumption pattern, however, is one of localized shortages. For example, although Texas uses more than half of the refractories consumed in the South Central United States, production of refractories in Texas is relatively small. Also, the apparent self-sufficiency of the area is in terms of value produced rather than in terms of products consumed. Nearly all of the $6,425,000 nonclay refractories consumed in the area were shipped from other States. Local resources possibly could be developed for making refractories to serve markets that currently are being supplied from outside the area. Since other industries are growing rapidly in the area, the market for refractories is expected to continue to grow--more rapidly than the national market. The Missouri refractories industry is economically important nationally. Nearly one-fourth of the clay refractories produced in the United States are made in Missouri. Moreover, Missouri produces most of the higher grade clay refractories, about 62 percent of the high-alumina refractories, and 85 percent of the superduty refractories. The competitive position of the Missouri refractories industry is strong. The national market for clay refractories and the market in the South Central United States are expected to continue to grow. The ratio of net income to the value of refractories shipped in Missouri is larger than the national average.

Jan 1, 1960

By W. S. Sanner

This report describes the commercial application of the launder screen in anthracite-industry fine-coal cleaning operations. No new device, the launder screen has been used since the early part of the present century to size, screen, classify, and deslime the fine-anthracite sizes (Buckwheat Nos. 1 through 5) recovered by "river-coal" men dredging along streams draining the anthracite fields. The launder screen is stationary, has no moving parts, requires ample water for operation, and can be constructed economically on the job. Essentially, it consists of a wooden trough with baffles placed through its width to form a well system. The wells are covered by fine-mesh woven-wire screening. Each well is tapped with a number of orifices, and the hydraulic suction head developed in this manner removes high-gravity fines and slimes through the screening as underflow to waste. Material retained on the screen surface discharges as overflow product.

Jan 1, 1954

By L. J. Froisland

The U.S. Bureau of Reclamation requested U.S. Bureau of Mines (USBM) assistance in developing design data for moving lead-zinc-gold tailings from their current location without disrupting the existing chemically stable conditions. This report presents results of USBM work in determining (1) the minimum required time to air dry the tailings to approximately 20 pet moisture under various drying conditions both in the laboratory and in the field, (2) the degree of oxidation or reduction that occurs during drying, (3) the effect of lime or cement addition before drying, and (4) the likely equilibrium conditions of the dried tailings after deposition at the new location. The limited number of tests performed by the USBM in the available time frame established trends in oxidation levels but did not provide absolute statistical validity of data values. All data from drying and oxidation testing are included in appendices to this report.

Jan 1, 2010

By M. E. Tyrrell, J. Koster

This work was undertaken to determine the feasibility of making mixed diborides of two metals directly from the metal oxides , boron carbide and carbon . The diborides (Ti , V ) , B₂ , (Ti , Cb) B₂ , and ( Ti , Ta ) B₂ were prepared in a crucible resistance furnace at 2,100 ° C , and X- ray- diffraction analyses showed each was a homogeneous solid solution containing approximately equal molar contents of the given diborides . The diboride powders were cold - pressed ; sintered to 2,300 ° C , and evaluated for mechanical strength , rate of oxidation , and resistance to molten metals . The diboride ( Ti , Ta ) B₂ exhibited the best mechanical properties ; the diboride ( Ti , Cb ) B₂ , the lowest cumulative rate of oxidation . The mixtures were stable in the presence of molten aluminum and copper but were attacked by molten Ti , Zr , and Cr .

Jan 1, 1964

By Frank C. Morris

This report presents the results of a Bureau of Mines study to identify clays found in several petroleum-reservoir rocks in the Tejon-Grapevine area, Kern County, Calif., and to determine the effect of water sensitivity of the clays on the permeability of the reservoir rocks. The clays in the porous rocks were examined in detail, and the clay-mineral types were identified by differential thermal analysis, X-ray diffraction, and optical and dye-staining methods. Fresh-water damage to the permeability of the oil-reservoir rocks was indicated by a study of 125 core samples from productive formations. The study indicated that, although clays were generally less than 5 percent of the reservoir rocks, they swelled in water, particularly fresh water, and nearly blocked the flow channels through which oil flows to the well, effectively reducing the permeability of the formations. The average permeability of rock decreased from 1,600 millidarcys in air to 620 millidarcys in salt water and 120 millidarcys in fresh water. The dominant clays in the oil-bearing sandstones were members of the montmorillonite group. They were associated with smaller quantities of clays found to be in the mica or illite group. None of the cores appeared to contain clays of the kaolinite group. In the lower section of the J.V. sandstone indications of what appeared to be the mineral sepiolite were noted.

Jan 1, 1959

By R. R. McLellan

The Brown Derby pegmatites are in Gunnison County, Colo., about 18 miles east of Gunnison. Approximately 860 tons of lepidolite concentrates, with smaller amounts of microlite and beryl, was produced from 3 dikes of the Brown Derby group from 1943 through 1947. No mining was done from 1948 until December 1950, when production of lepidolite and beryl was resumed by the Poston Mining & Milling Co. Mining was intermittent during 1951 and 1952. The dikes were mapped and studied by the Federal Geological Survey during the field seasons of 1942 to 1944, and in May 1950 the Bureau of Mines initiated a diamond-drilling project to test the three dikes for lepidolite and beryl. After being recessed twice, the project was terminated indefinitely July 1951. Seven drill holes were completed for a total of 1,841.6 feet of drilling.

Jan 1, 1956

By Thomas C. Atchison, Joseph M. Pugliese

Six explosives were compared by measuring their strain- producing abilities in limestone . Peak strain , e , varied with scaled distance , R/Ro , according to the following equation : € = Kc (R /R 。)- ". The distance exponent , n , was a constant of the rock and did not depend upon explosive . The strain intercept , Ke , increased with increasing detonation pressure of the explosive . The strain intercept also depended upon the explosive- to - rock impedance ratio . For impedance ratios from 0.53 to 1.38 , the strain intercept was approximately proportional to the medium stress , Pn , as calculated from the explosive detonation pressure , P , and the explosive - torock impedence ratio , Z , by the simple elastic theory relation : P = 2P / ( 1 + Z ) . PD However , the data indicated that , at lower values of impedance ratio , the strain intercept is relatively larger than would be expected from the simple elastic theory . The results presented provide a simple method for predicting the relative effectiveness of different explosives in breaking limestone from the detonation pressures and characteristic impedances of the explosives .

Jan 1, 1964

By Donald P. Blasko

The Bureau of Mines investigated two areas of oil and gas seeps in the north-central Gulf of Alaska--Katalla River to Bering River and Cape Yakataga to Yakutat Bay to determine (1) whether previously reported seeps are still active, (2) the characteristics of the seeping hydrocarbons, and (3) the amount of bitumen contained in the drainage leaving the seeps and entering the Gulf of Alaska. Thirteen separate oil seeps, six bitumen deposits, and eight gas seeps were located, sampled, and analyzed. The oils ranged from 35.2° to 14.1° API gravity and had sulfur contents from 0.53 to 1.31 wt-pct. Bitumen samples had API gravities from 2.4° to 14.6° and sulfur contents from 0.28 to 0.88 wt-pct. Gas samples had specific gravities ranging from 0.577 to 0.883 and caloric values from 724 to 1,427 Btu/cu ft. A total of 63 water samples obtained from seep locations and seep drainages were analyzed by atomic absorption spectrophotometry for ionic content and by solvent extraction for hydrocarbon content. Although some of the water at the oil seeps had a bitumen content as high as 246,000 mg/1, the amount of hydrocarbons actually reaching the Gulf of Alaska averaged <0.2 mg/1.

Jan 1, 1976

By Terry L. Muldoon

The report describes the development of preliminary requirement specifications for standardized operating controls for roof bolting machines used in underground coal mining. According to recent statistics, roof bolting continues to be one of the most hazardous occupations in underground coal mining. The two principal hazards to the roof bolter operator are the machine itself and roof falls during the bolting cycle. The lack of standardization of machine controls is a major contributor to this hazardous situation. Observations of roof bolting operations and discussions with roof bolter manufacturers coupled with detailed analyses of roof bolter control design specifications were performed during this study. Detailed roof bolter operator task analyses, commonality of control analyses, and classical link analyses were also performed. The results of these analyses were then used to produce preliminary requirement specifications for standardized controls.

Jan 1, 1980