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By Joseph B. Huvos

Said to be one of the world's most under-developed countries, Benin had a gross national product (GNP) estimated at $1 billion in 1980.2 Contribution of the mineral industry such as cement and limestone to the GNP was negligible, but exploration of mineral potential continued Minerals.-The United Nations Development Program (UNDP) conducted an investigation of three deposits from 1977 to 1980: Phosphates (Mekrou), gold (Perma), and chromite (Buem). A phosphate rock deposit containing about 4.5 million tons recover- able by opencast techniques was discovered. It was not known if the gold and chromite deposits were recoverable economically. Iron ore deposits of some 230 million tons near Loumbo-Loumbo are at present not exploitable because of lack of infrastructure in the northern part of the country. Geologic mapping with British and French assistance was also pursued in 1980.

Jan 1, 1982

By T. S. Golosinski

Most of the 154 t (170 st) truck fleets that were predominant in large surface mines in the 1970s and 1980s are approaching the end of their economic life. One replacement option considered by mine operators is a change to the 2 18 t (240 st) trucks. A comparison of load capacities between the 1.54 t (170 st) and the 2 18 t (240 st) trucks indicates a large productivity advantage in favor of the 218 t (240 st) trucks. This advantage, however, is often reduced by a number of site-specific factors. Therefore, a careful evaluation is required to define the actual benefit of changing to the large trucks. This article discusses some important factors that have an impact on truck size selection, based on several different studies. 218 t (240 st) trucks The 2 18 t (240 st) rear dump trucks were first introduced for surface mine service almost 10 years ago. However, it is only during the last few years that this equipment has gained acceptance in the surface mining industry. About 250 units were employed in surface mines worldwide at the beginning of 1992, and further purchase commitments are being made. Encouraged by the mining industry’s interest, all major off-highway mining truck manufacturers now offer 218 t (240 st) models (Table 1). At present, the existing 218 t (240 st) truck fleets are dominated by electric drive trucks. However, recent introduction of a 2 18 t (240 st) mechanical drive truck rounds out the development of this truck size.

Jan 1, 1992

By L. B. Pankratz

Thermodynamic data on carbides, nitrides, and other selected substances were reviewed, evaluated, and compiled at the U.S. Bureau of Mines Albany Research Center. Values for Cp°, S°, H° - H°298, -(G° - H298)/T, ?Hf, ?Gf, and log Kf are given in tabular form. Cp°, H° - H°248, ?Hf°, and ?Gf° are also expressed algebraically.

Jan 1, 1994

By N. Greninger

The Bureau of Mines conducted a laboratory study of the measurement of the water and rock dust (RD) contents of synthetic mine-type coal dust (CD) mixtures using a commercial unit for measuring water content and several prototype radiometric units for measuring the RD content. The RD content ranged from 50 to 100 wt pct and the added water (AW) ranged from 0 to 15 wt pct. The total water (TW) content (intrinsic (IW) and AW) of a small dust sample could be readily measured automatically by essentially untrained personnel using a commercial unit. The RD content of a sample containing only IW could readily be measured by moderately trained personnel using several radiometric units. With gamma-ray devices, about 300 g of sample is needed. With the improved beta-ray device, about 25 g of sample is needed. With dry mine dust samples, the estimated RD error range for gamma-ray devices is 0.8 to 2.3 pct and 0.5 to 1.0 pct for beta-ray devices. However, the radiometric measurement of RD content was questionable if the dust mixture also contained AW or if it was uncertain whether the dust mixture contained AW.

Jan 1, 1988

By M. Dupuis

Recently, a new approach to controlling alumina feeding in a H.H. cell has been proposed [1, 2 and 3]. This approach, labeled In Situ aluminium cell control, is based on a correlation between the slope of the cell voltage during a no feed observation period and the dissolved alumina concentration in the bath. Once the dissolved alumina concentration has been estimated, a primary calibration surface uniquely relating the dissolved alumina concentration and the anode-cathode-distance (ACD) to the cell voltage is used to estimate the cell ACD. Once both the alumina concentration and the ACD have been estimated at the end of the observation period, a PID controller can be used to regulate the rate of alumina feeding using only the normalized cell voltage to calculate the error between the estimated dissolved alumina concentration and a target value. The In Situ aluminium cell control algorithm has now been tested with the Dyna/Marc [4, 5 and 6] cell simulator demonstrating that it should be possible to control a H.H. cell in this manner with less variation in the dissolved alumina concentration and other process variables producing a prediction of improved cell current efficiency and power efficiency.

Jan 1, 2011

By D. F. Kidd

Introduction In a companion article, Surveys at Great Bear Lake, 1931, R. C. McDonald has described the general character, topography, and climate of the Great Bear Lake-Coppermine River area and the main means of access (l). The present paper will largely be confined to the geological features of the district. In the last two years, the rocks of the region have received considerable attention, and papers including references to .the geological succession have been written by Knight(2), Duncan(3), Norris( 4), Reid(5), Cameron(6),and Kidd(7). The writer confined his field-work during the 1931 season to the district between LaBine point and Hunter bay and northwest to the head of McTavish arm. Brief trips were made down the Sloan river from McLaren lake, 25 miles northeast of Hunter bay, to that place, to Dowdell (Sixty-six) point, the south point of Echo bay, and to the region north of the Dismal lakes and west of the Coppermine river. The inner part of Echo bay, which is the area discussed by Reid and Cameron, has not been seen by the writer and the geology there will not be discussed.

Jan 1, 1932

By Fred C. Turin

The U.S. Bureau of Mines conducted a human factors analysis of hazards associated with roofholting activities in underground coal mines. Emphasis was placed on hazards related to the movement of the drill-head boom or mast of a roof bolting machine. The objective was to identify hazards and recommend solutions. The data-collection effort consisted of analysis of U.S. Mine Safety and Health Ad-ministration accident data; visits to underground mines and interviews with experienced roof bolting machine operators; discussions with roof bolting machine manufacturers; interviews with workers injured while performing roof bolting tasks; and reviews of research on roof bolting safety. A set of recommendations to increase the safety of roof bolting operations was developed. In particular, the following list of recommendations was presented in ranking order: (1) use an interlock device to cut off power to controls when an operator is out of position, (2) place fixed barriers at pinch points, (3) provide appropriate control guarding, (4) reduce fast-feed speed, (5) use automatic cutoff switches at pinch points, (6) redesign control bank to conform to accepted ergonomic principles, and (7) use resin insertion tools and resin cartridge retainers.

Jan 1, 2010

By E. J. Owen, S. Cherotich, V. T. McLemore

Breccia pipes are vertical pipe-like columns of rocks that provide conduits for fluid flow and open spaces for mineral precipitation, hence are focus areas for exploration. In the Gallinas Mountains, Lincoln County, New Mexico, there is recorded production of Cu, Pb, Ag, F, Fe, REE (as bastnäsite), and Au from 1902 to 1980, but no production reported from the breccia pipes. Previous studies described the occurrence of REE in breccia pipes, but their transportation and deposition controls are still unclear. The aim of this research is to characterize the magmatic-hydrothermal breccia pipes in order to understand the geochemical and physical conditions of deposition of REE and gold in the breccia pipes found in the Gallinas Mountains. There are more than 20 exposed breccia pipes that form a NE-trending belt about 3–5 kilometers, mostly gray-brown and consist of angular- to sub-rounded rock fragments, some host high concentrations of REE (80,500 ppm total REE) and Au (175 ppb). Preliminary studies suggest they are magmatic and intruded into the host rock and, subsequently, hydrothermal fluids precipitated F-REE and Au along the edges of some breccia pipes. More studies are underway to test this hypothesis.

Feb 1, 2023

The Mine Safety and Health Administration (MSHA) defines an independent contractor as any person, partnership, corporation, subsidiary of a corporation, firm, association or other organization that contracts to perform services or construction at a mine. Contractors that perform specific types of work are required to report the number of employees who work at coal mines and noncoal mines.

Jan 1, 2008

By H. M. Smith

The production of oil during the early development of new oil fields is usually accompanied by large quantities of natural gas. Since in most fields gas under pressure is the main source of the energy causing the oil to move through the sands into the wells and thence to the surface, coincident production of natural gas will continue as long as present-day producing methods are used. Generally the use of this gas is restricted, since markets are not readily available. Consequently, a large portion of the gas produced is often wasted by being blown into the air. The magnitude of gas waste is well brought out in the following statement by Miller: Only a few outstanding examples need be cited to show the enormous production of gas that accompanies the discovery of new sources. In April, 1927, the Ventura field produced approximately 210,000,000 cubic feet of gas a day; and during the summer of 1927 Alamitos Heights reached a peak gas production of 102,000,000 cubic feet a day; on December 1, 1928, as a result of the summer's deeper drilling in the Long Beach field, surplus gas production amounted to 125,000,000 cubic feet a day. It is estimated that in January, 1929, the Santa Fe Springs field will have a daily gas production of 387,000,000 cubic feet from the recently discovered Buckbee oil zone. Of this amount 274,000,000 cubic feet a day will be the surplus above the amount required for field and plant fuel, taken out by utility corporations, and that used in repressuring the Meyer sand which lies above the Buckbee zone. Another example of the waste of large volumes of gas is in the Turner Valley field of Canada, 6 where 250,000,000 cubic feet of gas is being burned daily in flambeaus, as there is no present outlet except at prohibitive cost.

Jan 1, 1931

By Virginia T. McLemore, Abena S. Acheampong-Mensah

Critical mineral endowment of mine wastes in two mining districts in New Mexico (Copper Flat at Hillsboro and Carlisle-Center mines in the Steeple Rock district) will be characterized and estimated. “Beta-testing” of USGS procedures was performed. Potential critical minerals at these deposits include As, Bi, Te, Zn, Co, Ni, Mg, Mn, and fluorite. pH and particle size of samples were analyzed to determine weathering and migration potential of heavy metals. Soil pH was also measured to determine the potential for Acid Rock Drainage. The pH of the waste rock piles ranged from 3.66 to 5.67 which indicates fine- grained pyrite or sulfide oxidation. The samples collected from the tailings however, showed a different range of pH, from 6.30 to 8.62, probably due to the presence of carbonates. Difference in particle size fractions and its distribution along the slope are generally influenced by natural occurrences (e.g., gravity and pre-mining hydrothermal alteration) and operational activities such as material piling or dumping. Future work includes analyses of mineralogy and particle size correlation and estimation of critical mineral endowment of these mine wastes at New Mexico.

Feb 1, 2024

By Sebastian Siebert

Unmanned Aerial Vehicles (UAV) as a data acquisition platform and as a measurement instrument have become attractive for many surveying applications in civil engineering. However, their performance is not well understood for these particular applications. The specific scope of the presented work is the performance evaluation of a UAV system that was built to rapidly acquire mobile 3D mapping data for large earthmoving construction sites. Details to the components of the developed system (hardware and control software) are explained. A novel program for photogrammetric flight planning and its execution for the generation of 3D point clouds from digital mobile images is explained. A performance model for estimating the position error was developed and tested in several realistic construction environments. Results to these tests are presented as they relate in particular to large excavation and earth moving construction sites. Results and experiences with the developed UAV system are in particular useful for researchers or practitioners in need for successfully adapting UAV technology for their application(s).

Aug 1, 2013

By Franklyn Oatman

IN order that the conditions which obtain in an oil well may be readily understood, a brief description of a typical California well and. a number of the phenomena accompanying same will be given. That the necessity for the exclusion of water be realized, the effects of water intrusion, a description of methods of prevention, and a discussion of causes of failure will be presented, followed by a summary and recommendations. Fig. 1 shows a section of a typical well which illustrates the relation of oil sands to overlying strata. It indicates a deep water sand separated from the oil sand by shale, and the proper place for the final shutting off of water. In this well a comparatively thick stratum of compact shale protected the oil from overlying water so that the operation of landing the water string was a simple matter. In some wells the protecting stratum may be only from 3 to 5 ft. thick and very careful operation is necessary in order to land the water string of casing properly and not puncture through to the oil sand. The cases just cited are common, but occasionally, after excluding overlying water, productive oil sands are drilled through in the expectation of finding more productive underlying sand, and a water-bearing stratum is tapped. In this case the problem is the reverse of the normal; water must be prevented from ascending rather than descending. A discussion of well-drilling methods is not within the scope of this paper, except such operations as pertain to shutting off of water. A brief outline of the several conditions which may accompany drilling follows. Some or all may be present in any particular case. The direct relation of these to prevention of intrusion will he discussed in detail further on. In drilling, the hole. becomes more or less irregular in shape, and rough, and as the casing follows the bit into the well it does not fit snugly against the walls. As a result, water may descend between the casing and walls of the well. If a circulation pump is not used during drilling, the hole is simply punched through and the pulverized material removed from the well by means of a bailer. If circulation is maintained there is a continual flow of water down inside the casing and up around the outside between the pipe and the walls of hole. This keeps an open. space around the pipe.

Jan 3, 1914

By D. F. Strong

Most Newfoundland. mineral deposits can be clearly classified as within rocks formed either as accreting plate margins (ophiolitic pyrite-chalcopyrite massive sulfides such as Betts Cove, Whalesback, York Harbour, chromite at Lewis Hills, and asbestos at Baie Verte), at consuming plate margins (Kuroko-type polymetallic massive sulfides such as Buchans and Pilleys Island, porphyry-type Mo-Cu at Rencontre, fluorite at St. Lawrence), or within plates (zinc deposits at Daniels Harbour, sedimentary iron ores at Wabana, manganese in Conception Bay.) As these metallogenic patterns can be convincingly extrapolated southward into the Appalachians and northward to the Caledonides, they provide an important means of eliminating and selecting areas for particular exploration targets. Sonic criteria are described for the recognition of these environments of differing economic potential.

Jan 1, 1973

By Y. Chengxian, F. Yaorong, Xinzhe. L.

Many factors about the HIC (hydrogen-induced cracking) resistance of pipelines are discussed in this paper. The main factors that influence the ability of HIC are environmental and material factors. The chemical compositions, non-metal inclusions and microstructure are discussed in detail, while a group of tests on HIC resistance are done according to varying C, S, Mn and P contents in pipeline steels, different experiment time and different strength to the coupon. It is concluded that decreasing the amount of C and S can obtain good HIC resistance; the test time has an effect on the different microstructure of X70; microstructure is the most sensitive factor for the initiation processes of HIC.

Jan 1, 2005

By Thomas C. Shrake

The Lomas Bayas copper property is located93 km (58 miles) east of Antofagasta, Region II, Chile (Fig. 1). The deposit was discovered in 1880. The deposit produced intermittently until 1992. Production at Lomas Bayas took place in high-grade veins and breccias mined underground. During 1991, Empresa Minera Mantos Blancos SA (EMMB) optioned the property from Compania Doña Ada SA. Doña Ada maintained the right to continue mining the ores by open-pit and block-caving methods and hauling the ore to its plant located60 km (37 miles) to the north. EMMB conducted exploration and column test programs. On May 9, 1994, Compania Minera Gibraltar Ltda.(CMGL) signed a purchase option agreement to acquire the Lomas Bayas property. CMGL conducted 8,612 m(9,490 ft) of reverse-circulation drilling, 2,028 m (6,650ft) of diamond drilling, a series of metallurgical tests and geologic mapping. The company then decided to exercise its purchase option.

Jan 1, 1996

By Richard P. Curtin, John M. Goris, Lewis A. Martin

Cable bolt supports are being recognized as an effective ground control system in under-ground coal mines in North America, and their use has increased considerably during the past few years. The U.S. Bureau of Mines personnel are conducting both laboratory and field tests to evaluate the performance of these supports under a variety of conditions and to establish realistic design guidelines. This paper describes efforts to evaluate the capability of cable bolts to resist the high shear forces often present in longwall operations. Shear tests were conducted on pairs of 0.025 m3 (0.88 cu. ft) concrete blocks having joint surfaces ranging from rough to smooth. Tests were conducted on blocks both with and without reinforcement with 15.2 mm (0.6 in.) diameter steel cables. During each shear test, the loads and displacements along the normal and shear axes, as well as loads on the cable, were monitored. Cableloads were determined using strain gauges attached to the outside surfaces of the barrel-and-wedge anchors used for pretensioning the cables. Test results show that a cable bolt placed across a joint more than doubled shear resistance of shear blocks having both smooth and rough joints.

Jan 1, 1996

HIGHWALL MINING - DECISION TO MINEUlan had completed operations in the first Open Cut area due to high stripping ratios and the presence of geological features which destroyed a significant portion of the coal in the upper part of the seam. The pit had been abandoned in 1994 and operations had moved to a new location to the north west.

Jan 1, 1998

The production and processing of crude petroleum and natural gas are the dominant economic sectors of the Middle East, providing more than 80 % of the region's foreign exchange. In 1992, the 15 countries that constituted the region accounted for 29.5 % of world crude petroleum output, 20 % of world natural gas plant liquid production, and 5 % of world dry natural gas production. Only Cyprus and Lebanon were not crude petroleum producers. A fairly wide range of non fuel minerals is also produced in the region. The most significant are boron minerals, bromine, chromite, gypsum, phosphate rock, potash, strontium, and sulfur. However, the variety of minerals produced, output levels, and the size of the overall non fuel mineral economy of the region is dominated by Iran and Turkey. Turkey, with a diverse mineral production and strategically situated between Europe and the Middle East, was first in world production of run-of-mine boron minerals, second in strontium behind Mexico, and fourth in pumice. It was also a significant world producer of chromite, magnesi'lm compounds, mercury, and sodium sulfate. Turkey was also the Middle East's largest cement and steel producer. Iran continued to expand output of most mineral commodities following the war with Iraq from 1980 to 1988. It was a significant world producer of gypsum and strontium and on its way to becoming a major iron and steel producer in the region. Despite a very small domestic mineral industry, Israel was second in world production of bromine and a significant producer of phosphate rock and potash. In terms of processed minerals, Israel was a major world diamond cutting center and exporter of cut diamond. Jordan ranked sixth in world production of phosphate rock. Saudi Arabia was eighth in world production of sulfur.

Jan 1, 1994

By D. Papazoglou

This work was undertaken to investigate the thermodynamic and kinetic feasibility of using hot sulfur dioxide bearing gases from smelting processes to selectively sulfate the nickel in nickel laterite ores for subsequent extraction in water. The environmental benefits ofthis approach, as opposed to releasing the gas to the atmosphere, and the economic benefit of directly utilizing the S02 rather than converting it to sulfuric acid are strong drivers for such a process. A thermodynamic analysis indicated that selective sulfation of the nickel could be feasible under appropriate conditions and these were explored through a series of laboratory scale experiments. Laterite samples were reacted at temperatures between 500 and 800°C with an equilibrated mixture of sulfur dioxide, oxygen and nitrogen in a fixed bed reactor. Tests were conducted on saprolitic ore from Bulong, Western Australia, limonitic ore from New Caledonia and garnieritic ore from Indonesia. Nickel extractions were highest from the limonite and relatively low from the other ores. The maximum selective extraction of nickel from the limonite in a single stage sulfation was 73%. Sulfation of other elements present in the laterites was also examined. A two-stage process was also identified which involved sulfation using a strong sulfation potential followed by weaker sulfation potential to attempt to convert ferric sulfate formed in the first stage to ferric oxide. This increased the extraction for the limonite ore to around 84% Ni, 95% Co and 2% Fe. Direct sulfation of laterite could be feasible in locations where sulfide smelting or roasting operations are relatively close to laterite deposits.

Jan 1, 2003