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By R. L. Marek

The number of Persons fatally injured in the petroleum industry in California in 1930 was 50, a decrease of 20.6 per cent from 1929, when 63 men accidentally lost their lives. The decrease in the number of fatalities for 1930 has caused the first downward trend in the fatality curve of the California petroleum industry since 1927 and is coincident with a period of little active development in new fields, the shutting in of many wells, and reduced activity in the older fields of the State. That a direct relationship exists between the number of accidental deaths and the rapidity of new field development is particularly emphasized by the fact that in 1929, a year of intensive field development in California, 48 men were killed in the drilling and producing division, whereas in 1930, a year of less development work, only 25 men were killed in this division. The figures for the average number of drilling and producing wells in 1930 decreased appreciably from comparable figures for 1929 and a greater percentage of producing wells were shut-in in 1930 than in 1929.

Jan 1, 1931

By T. J. Cox

The Red River is located within the Sangre De Cristo Mountain Range in northern New Mexico. An approximate 12-mile segment of the river from the town of Red River to the village of Questa (Questa) includes several hydrothermal alteration zones. Alteration ?scars? formed as a result of rapid chemical weathering and physical erosion of pyrite-rich hydrothermally altered rocks. Storm water runoff from the scar drainages contributes metal-laden, acidic water to the river and creates a visible plume of discolored water in the river. Acidic runoff reduces the river pH from 7 to the mid 3s for at least 2 hours during large storms and the low pH water continues downstream. Runoff from scar drainages increases some metal concentrations in the river from below chronic ecological criteria to as much as two orders of magnitude greater than acute ecological criteria, and results in acutely toxic conditions for macro-invertebrates. A general improvement in the river?s water quality occurs downstream due to dilution from tributary inflow from non-mineralized watersheds, the natural buffering capacity of the river, and storm water controls at the Chevron Mining Inc. Questa mine.

Jan 1, 2011

E. A. HOLBROOK,*Urbana, Ill.-To those who have followed the development of powdered coal two questions often occur. First, as to the moisture in the coal. In Illinois we recognize that the bituminous coals contain about 12 to 15 per cent. of what we call "contained moisture," that is, the moisture is present in the coal although this may appear absolutely dry and dusty. In addition, the surface moisture may be present in any amount. I would like to ask what is the relative effect of these two forms of moisture upon the work of pulverizing. Does Mr. Collins refer to the contained moisture or to the surface moisture in estimating the degree to which the coal must be dried? H. R. COLLINS.-In the lignite coals, of which this country possesses a great deal and is beginning to develop them to considerable extent, the "contained" or "combined" moisture does not .trouble us; we have no difficulty in reducing lignites to a high degree of fineness. But when dealing with bituminous, sub-bituminous, or semi-bituminous, we, prefer to reduce the combined moisture as well as the hydroscopic moisture as far as possible. We have recently put into operation, at a plant, furnaces and boilers consuming the lignite from northern New Mexico, which contains between 4 and 5 per cent. moisture as we pulverize and burn it. The evaporating efficiencies under the boilers have been so remarkable that we wish to check the results half a dozen times before quoting them. We have also just started two boilers at the Garfield smelter, and have obtained the same high efficiencies.

Jan 11, 1918

The Institute has concluded an agreement with the Chamber of Mines whereby the Chamber Librarian maintains a section in the Library for the Institute. Surface effects of underground mining South Africa is blessed with vast mineral resources. It is essential to exploit those reserves if the country is to remain economically viable. Surface-mining equipment The Goldfields Mining Expo '86 is to be held in Kalgoorlie, Western Australia, from 30th October to 1st November, 1986, in conjunction with the Annual Conference of the Western Australian School of Mines. Mintek reports Report M142D Characteristics of gold and pyrite flotation at the Chemwes plant. (1st issued May 1984.) Report M159D Beneficiation tests on andalusite ore from the Marico district. (1st issued Aug. 1984.) Report M164D The recovery of tungsten from South African low-grade schee/ite concentrates. (1st issued Sep. 1984.)

Jan 1, 1986

By Gianfranco Di Cicco

Seepage problems were recorded for more then 40 years at the Walter F. George lock and dam. In 2001 the Mobile district of The U.S. Army Corps of Engineers turned to the installation of a 200 feet deep cut-off in a final attempt to remedy the situation. The advertised design-built contract requested the installation of the cutoff wall in front of the concrete structure of the dam starting from 90 feet of water, cutting through a concrete lock structure, a submerged retaining wall and extending on both sides on the earthen embankments. This paper summarize the history of the project and the installation of the first recorded cut-off wall constructed under deep water, upstream to an existing dam structures and under an existing concrete lock. The technology used combined with the project's results may be considered a milestone in the marine foundation and the marine cut-off wall construction technology.

Jan 1, 2013

By N. Aouad

Dump truck operators are exposed to whole-body vibration (WBV) levels that exceed the International Standard Organization (ISO) 2631-1. The WBV level measured by RMS acceleration value, for operator comfort, and long-term health and safety is under 0.315 m/s2 by these standards. However, fundamental research by Frimpong and Aouad (2009, 2012) and field experimental study by Kumar (1999) have shown that operators are exposed to extreme WBV levels exposing them to injuries and musculoskeletal diseases in the long-term. These extreme WBV values in the vertical direction are equal to 3.56 m/s2, 1.12 m/s2 and 0.87 m/s2 for the operator?s seat, lower-back and cervical regions, respectively. This paper will outline current research to solve these problems. Keywords: WBV, Truck Vibrations, MSC.ADAMS, Virtual Prototyping

Feb 27, 2013

By M. J. Fairweather

"The development of means to maximize the selectivity between galena and sphalerite in lead zinc ores is extremely important to the lead-zinc industry. Two challenging studies recently undertaken by Cominco will be reviewed. The first required an unusually fine grind to achieve liberation between galena and sphalerite. The second contained partially altered galena which resulted in unusual early activation of sphalerite under normal flotation conditions. Means by which lead and zinc separation were optimized in these two ores will be discussed.There are two important factors in the separation of minerals by froth flotation: particle size distribution (grind) and pulp chemistry. Pulp chemistry includes a number of factors including pH, Eh, collector type and concentration, inorganic depressants, organic depressants and activators.Grind is important for two reasons. A sufficiently fine grind is required to optimize liberation. However, if the mineral dissemination is too fine, mineral selectivity in the flotation process is impaired. Due to the hydrodynamic constraints of conventional mechanical flotation cells, flotation works best over the single decade size range between 10 and 100 microns. The majority of new ores treated by Cominco until relatively recently were comparatively simple. The major factor in their treatment was defining optimum grind size. Accordingly, the focus within mineral processing at Cominco was on grind and supporting liberation studies. The relationships between grind, liberation and flotation response are intuitively easy to understand. An idealized relationship is shown in the first figure."

Jan 1, 1991

By C. Melvin Lepper

Microseismic energy is generated when stresses accumulated in rock formations are released in the form of fracturing. The acoustic emissions resulting from these rock fractures and movements are detectable as velocity signals in the earth near the energy source. A Bureau of Mines microseismic system that is capable of detecting the acoustic emissions from pit slope movements is described. The digital circuitry incorporated in the system allows a microprocessor program to immediately calculate and present the location coordinates for the seismic energy source in the mine pit wall. This monitoring system is compact, portable, reliable, and relatively inexpensive and rapidly provides accurate information to the mine operators about the stability of a pit slope.

Jan 1, 1982

By Tien J. C

Many factors (type of coal mined, water pump pressure, wetting agent concentration, etc) will affect the performance of a dust suppression system using a water spray in an underground coal mine. While a two-level factorial method is useful in

Jan 1, 1994

By A. H. Balch

A physical elastic seismic model, based on the Peoria oil field was constructed and used to produce multi mode cross-borehole seismic data. Because this was a physical model, it was necessary to deal with a complex wave field consisting of compressional waves, shear waves, and converted waves. The recorded raw data were complex, have no resemblance to the inter-well geology, and were difficult or impossible to interpret. These unintelligible data sets were extensively computer processed. Detailed, accurate, images of the inter-well structure, and reflecting horizons were obtained as a result of this processing. This investigation demonstrates that excellent, accurate images of the inter-well geology can be obtained by skilled seismic cross-well data acquisition and extensive careful computer processing.

Jan 1, 1993

The Forestry Reclamation Approach (FRA) specifies that the upper 1.22 m of material on the reclaimed surface should be left as uncompacted as possible to facilitate tree root growth. One of the main concerns about applying the FRA to steep slopes is that the upper 1.22 m of material could cause the reclaimed slopes to be unstable. Successful application of FRA on flat and rolling surfaces precipitated this investigation. Details of a field investigation conducted at a steep-slope mine are available in an earlier publication (Kumar and Sweigard, 2011). A total of 70 survey monuments were driven into the slope in a regular pattern to monitor slope movement. Quarterly surveys of the monuments were done to quantify any type of mass movement either horizontally or vertically. The methodology proposed for slope movement was verified using numerical models. Analytical models based on limit equilibrium technique and numerical models based on the finite element method were developed for slope stability analysis. The limit equilibrium analysis was done using Geo-Slope software following the Simplified Bishop Method. The finite element (FEM) numerical model was developed using the Plaxis computer program following the strength reduction technique. Two kinds of slope stability analysis were performed: first with the top 1.22 m of loose material and second without top loose material. Finally, the field investigation results were compared with stability analysis results. Both of these approaches showed that application of the FRA on steep slopes is not causing any significant instability problems that would not exist otherwise for overly steepened slopes. Keywords: Forestry reclamation approach, steep slope, slope movement, factor of safety

Feb 27, 2013

By A. V. Henry, W. Harry Vaughan

THE kaolins of the southeastern United States were known to civilization as early as the latter part of the eighteenth century-and yet the [ ] commercial history of Georgia kaolins may be said to begin in the year 1900. The U. S. Bureau of Mines reported for that year a production of 6885 tons of "miscellaneous" clays in Georgia. A comparison of these figures with those of 1934, when the production rose to 284,556 tons (65 per cent of the domestic production), indicates the growing economic and technologic importance of this raw material. Fig. 1 clearly shows that a part of the increase is due to a normal growth in the use of kaolinitic clays and a part is due to replacement of clays formerly imported. Occurrence Georgia kaolin occurs in an irregular belt extending diagonally across the middle of the state, a distance of approximately 225 miles. This belt

Jan 1, 1937

By Robert W. Metcalf

Since the spread of the European war virtually cut off imports from Denmark, Belgium, and France, the Bureau of Mines has had numerous inquiries as to domestic sources of grinding pebbles and silex or other types of ball mill liners. USES Flint pebbles and tube-rill liners are used by grinders of certain ceramic materials to prevent contamination of the finished product by iron abraded from steal baler and liners. The feldspar industry is one of the largest users of flint grinding mediums; they are employed also by curtain grinders of talc and soapstone, ground sand and sandstone, quartz, and chalk. Some paint materials, such as lithopone, have been ground in pebble Flint pebbles have been used more or less in the past, especially by cement manufacturers, and, for fine grinding of gold, copper, or other ores in which iron contamination is not especially deleterious.

Jan 1, 1940

By Christopher Haycocks

Subsidence induced innerburden shearing and stress fields, whether active or passive, frequently contribute to significant ground control failures in overlying seams. In this paper proven multi-seam technology is used on upper seams to forecast and quantify the magnitude and severity of damage and the increased mining risk due to interaction. Increased upper seam ground control problems are demonstrated using hazard mapping which provides a viable technique for utilizing damage predictions in design.

Jan 1, 1986

By V. G. Papangelakis, G. A. Moldoveanu

"One of the major commercially viable secondary sources of rare earths elements (REE) are the ion-adsorption ores, containing 0.05-0.3 wt% rare earth oxides physically adsorbed on the surface of clay minerals formed during weathering of lanthanide-rich rocks. Although ion-adsorption deposits are substantially lower grade than other types of rare earth sources, this is offset by the easier mining and processing costs and the low content of radioactive elements. The conventional extraction route involves ion exchange leaching with monovalent cation solutions (usually ammonium sulphate) under ambient conditions; during the process, the lanthanides are desorbed and transferred into solution, being replaced by the exchange cation. While ammonium ions are known to perform best, there is increased environmental motivation to investigate alternative lixiviants in order to minimize ammonium sulphate impact via reducing its use without considerable loss in rare earth recovery.The objective of the present research was to screen various cations salts (alkaline and alkalineearth metals present as sulphates, chlorides and acetates, respectively) in order to comparatively evaluate lanthanide desorption levels and provide a theoretical base of the observed behaviour. The overall aim is to gain a better understanding of how both cation and anion may affect the overall REE recovery from ores in order to provide alternative processing routes. The distinct exchange capabilities of cations were explained in terms of differences in cation hydration enthalpy within the same group, i.e. Cs+ > NH4 + > K+ > Na+ > Li+ and Ba2+ > Ca2+ > Mg2+. For the same cation, it was determined that REE extraction efficiency follows the order sulphate > acetate > chloride, based on dissimilarities in constants of formation values. Various process implications scenarios will be described based on using mixed cations and anion matrices."

Jan 1, 2016

Cataclysmic or flood-like release of gas-charged brines, hydrocarbons and slurries accompanied widespread mineralisation of Upper Devonian environments. These are well represented in the Canning and Burdekin Basins of Western Australia and Queensland respectively.The Burdekin Basin provides particularly instructive vein structural sequences. These fall into organic residue to carbonate paragenetic sequences which are known elsewhere to record progressive decarboxylation. Fibrous veins indicate overpressure in fractures with organic residues, acids and gas derivatives driven to overlying groundwater flows. This combination of large flow rates and potent organic mineralisers led to extensive arsenical rare-metal mineralisation which is similar to that concentrated in Upper Devonian extinction horizons of the Canning Basin. Organic-residue mineralisation appears concentrated by certain hvdrostructures and targeted upon particular species. These controls need to be understood to guide modern management stragegies for mineralised organic and nitrogenous wastes.

Jan 1, 1990

By Hoban M, Smith CJ

Norwich Park Mine commenced production of export coking coal in November 1979. Attention to consumables control was limited during the early running of the plant. Once higher than anticipated magnetite consumption levels were confirmed, efforts were directed at determining the causes. Extensive plant sampling, monitor- ing of operational procedures and plant modif- ications have led to a significant reduction in magnetite usage.

Jan 1, 1978

By G. T. Lineberry, R. Q. Honaker

Coal extraction typically results in the recovery of pure rock that ranges from small to very large quantities depending on seam thickness and other characteristics. The removal of pure rock may allow the recovery of three times the amount in middling coal particles, which has significant economical benefits. In an industrial example, a 150% increase in revenue was realized from deshaling a low-ash, run-of-mine coal and blending with a processed clean coal product. Deshaling is the process of removing pure rock from coal, which normally involves a high-density separation in a gravity-based process. The removal of the relatively pure rock near the point of extraction has the potential to further enhance the economics of an operation due to reduced materials handling and refuse storage costs.

Jan 1, 2004

By Richard J. Mainiero, Michael J. Sapko, Marcia L. Harris

Since 1988, there have been thirteen documented incidents in the United States and Canada in which carbon monoxide (CO) is suspected to have migrated through near surface strata into structures or other enclosed spaces as a result of nearby trench blasting or surface mine blasting. From these incidents, there are thirty suspected or medically verified CO poisonings and one fatality associated with these incidents. To better understand the variables contributing to this hazard, the National Institute for Occupational Safety and Health (NIOSH) carried out a small- scale field study to identify key factors that may contribute to the migration of CO through the ground. NIOSH conducted single- hole heavily confined experimental test shots to measure the radial pressure pulse as it propagated through surrounding monitoring holes to determine if a relationship existed between the pressure pulse and resulting CO measurements afterwards. NIOSH also monitored blasts at an airport construction site. Following the detonations, the concentrations of CO, nitric oxide (NO), and nitrogen dioxide (NO2) were monitored for several days in the surrounding satellite holes. The peak CO measurements relative to distances from the shots were compared. Pressure histories and peak particle velocities (PPV) were measured at monitoring boreholes. It was found that the differential pressures recorded within the boreholes give some indication as to the likelihood of CO appearing, whereas the PPV measurements do not seem to be as good an indicator for potential CO migration. In this limited study, changes in barometric pressure had very little influence on removing the trapped detonation products, whereas applying a vacuum to the monitoring holes was effective in reducing the entrapped CO concentration.

Jan 1, 2005

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

3. Preliminary Evaluation of Mine Sealing Techniques As the first stage in the development of a technique for the remote sealing of mines, a state-of-the-art survey of various mine sealing techniques was conducted. This was expanded to include a review of different materials offering some potential for use as a mine sealant. Techniques for the remote placement of materials for other applications were evaluated, and system concepts for dis¬tributing remotely placed materials were developed. This preliminary review led to the development of a functional description of a general mine sealing technique to meet the specified conditions. Various potential system configurations were synthesized. These were subjected to a preliminary evaluation based on estimated confidence in system performance, development risk, cost, and sealing time. Based on this preliminary evaluation, promising mine¬sealing techniques were selected for further development. This section presents a review of the following: (a) Techniques for constructing permanent seals from within a mine. (b) State of the art in remote sealing for mine fire control. (c) Techniques for remote placement of materials for other applications. (d) Systems for distributing remotely placed material. (e) Materials for mine sealing. (f) Synthesis of remote mine sealing concepts.

Jan 1, 1973