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By S. H. Lorain

Mechanized dirt-moving equipment has greatly increased the scope of prospect trenching by lowering the costs and increasing the speed of such work. Where the soil covering was more than 3 or 4 feet deep, operators were quickly discouraged and abandoned surface exploration in favor of shaft sinking, drifting, or diamond drilling; wildcat trenching was seldom undertaken, even where the soil covering was thin. Although power shovels, trench diggers, and draglines are useful under special conditions, caterpillar-mounted angledozers will usually do the same type of work and have a far wider range of adaptability. They are therefore incomparably the most generally useful equipment for the purpose. Since 199 the Bureau of Mines has been engaged in a widespread search for minerals useful to the war program; this work required a great deal of pioneer exploration in areas where known outcrops were marginal or subcommercial by pre-war standards. Engineers in charge of field operations were quick to perceive the applicability of mechanized trenching on a fairly large scale, particularly in the Northwestern States, where completely exposed vein-outcrops are rare. Probably no other organization to date has done a comparable amount of angledozer prospect trenching under such a wide range of conditions. The following comments and accompanying cost tables are based on work performed chiefly in Idaho, under a variety of physical and climatic conditions. The most important applications of the angledozer for such work may be described under three heads:

Jan 1, 1944

In 2007, a total of 725 nonmetal mining operations reported employment to the Mine Safety and Health Administration (MSHA).1 Nonmetal mines com-prised 4.9% of all m ining operations. ? Mines producing common clay comprised 25.4% (n=184) of all nonmetal mining operations. ? Nonmetal mining operations were located in all states and territories except Alaska, Delaware, Hawaii, Maine, New Hampshire, Rhode Island, Puerto Rico, and the U.S. Virgin Islands.

Aug 1, 2009

By Willard L. Hunter

The research described in this Bureau of Minus report was conducted to improve the chromium-iron ratio of offgrade chromite. Two methods were used: (1) Iron was selectively reduced from chromite by carbothermic reduction in an electric-arc furnace, and (2) a mixture of carbon, chromite, and sometimes fluorspar was chlorinated to remove a substantial part of the iron. Chromite concentrate from the Mouat deposit in Montana and from northern California was used in the test work. Chromium-bearing slag and chromite that had been beneficiated by a roast-leach process were each smelted to produce high-carbon ferrochromium. Iron was selectively reduced in a laboratory-scale., electric-arc furnace. Carbon additions to the smelting charges varied from 40 to 100 percent of the stoichiometric requirement, and slag basicities were varied from 0.4 to 1.0 chromium-iron ratios of more than 4:1 were obtained with 89 percent recovery of chromium in a chromium-bearing slag.

Jan 1, 1962

By Roy S. Nutter

The automation of coal mining must occur in a manner that is economically beneficial to the industry and that enhances the safety of the underground and surface workplaces. The work at WVU over the last five years in applying expert systems and neural network controlled autonomous robotics provides the mining industry with tools that when properly applied should clearly lead to mine-wide management and operational improvements and should also contribute to a higher awareness of safety issues by all work crews. This work includes the development of MMSS (Mine Management Support System) and the detailed development of autonomous robotics utilizing neural networks for mining systems.

Jan 1, 1993

By X. Q. Cao, D. S. Zhang, L. Q. Ma

To solve the support stability control problem for a coal face with large angles along both strike and dip (CLSD), the ’support-surrounding rock’ mechanical model has been developed, which takes into account the impact of the dip angle of the seam on the stability of the support in the strike direction. The mechanical relationships of the critical topple angle and critical slip angle of the support along the strike of the coal face with large dip angle and the support height, support resistance, friction coefficient, and other factors have been derived through the mechanical analysis of support stability in the strike direction of CLSDs in the free state, the operating state, and the special state. The research findings were applied to a fully mechanized CLSD in Xinji Coal Mine. The maximum underhand angle and overhand angle in strike are 42° and 25° respectively, and the maximum dip is 39°. It is calculated that during underhand mining and overhand mining, the critical support resistances for avoiding support toppling are 3723 kN and 1714 kN respectively, and the critical support resistances for avoiding slipping of the support are 7405 kN and 6606 kN respectively. Thus, the selection of type ZZ7600/18/38 hydraulic roof support for the coal face is justified. Measures to prevent sliding of the support and the installation of a limiting stop maintain the support runs in good condition and ensure safe and efficient mining of CLSD.

Jan 1, 2015

The regular activities of the Institute are financed mainly by income derived from members' dues, from advertising in MINING AND METALLURGY, and from the sale of publications to the public. In addition, collateral activities and special projects are financed each year by means of income from endowed funds controlled and administered by the Institute. In the aggregate, the principal sums of these endowments amount to more than $530,000. An active effort is being made to increase the endowment funds of the Institute through a standing committee, of which H. T. Hamilton is chairman, and of which the other members are: W. H. Aldridge, George D. Barron, Cleveland E. Dodge, D. C. Jackling, Henry Krumb and J. V. W. Reynders. This committee feels that there exists a tremendous opportunity for the Institute to be of ever-growing service to the public, to the mineral industries, and to the profession. It welcomes suggestions as to names of men of means who are vitally interested in the mineral industries, and to whom the opportunity to make a contribution or bequest might appeal favorably if presented in the proper light by the committee.

Jan 1, 1941

By Normal Seidle

This report (rind related Appendices) provides a description of the functional design specifications and related rationale for development of a training system for dragline equipment operators. Phase I activities involved a delineation and detailed analysis of specific behavioral requirements for successful dragline operation. Following the field data collection effort, job/activity/task descriptions were formulated into training requirements which can be achieved by a trainee with training hardware having specific functional capabilities. The training system analysis integrated the training requirements and the trainer functional capabilities into recommendations which configure a total training system. The objective of the training system described in this report is to provide new operators of dragline equipment with the requisite skills and knowledge to assure cost-effective development and an adequate supply of our human resources.

Jan 1, 1975

By R. Simonson

Agenda ? Need and Introduction ? Interface Management Programs ? Outcomes of Successful Interface Management ? Key Success Factors ? Lessons Learned ? Concluding Remarks Need for Interface Management ? Complex projects ? Larger in scale ? Physically dispersed and delivered remotely ? Involved with several stakeholders ? Risks thus imposed due to: ? Iterative and dynamic nature ? Large information flow ? Document revisions and information updates ? Related sources of Risk: ? Ineffective communication ? Poor work relationships ? Person to job mismatches ? Failure to clarify expectations

Aug 1, 2013

By J. P. Capp

The Bureau of Mines conducted field-scale experiments in underground gasification of coal with oxygen-enriched air. A path about 140 feet long was linked at the rate of LO feet per day through a coalbed hydraulically fractured with a mixture of starch gel and sand. During the best gasification period, which extended for 2-1/2 days, 785,000 std. c.f. per day of 124-B.t.u. gas was produced. In other periods the heating value at times was almost 300 B.t.u. per std, c.f,, but sustained production of such gas was not achieved. During gasification, a total of 50 tons of coal was gasified and 114 tons of coal was carbonized. Approximately 12 million B, t .u. per foot of nominal path was recovered at the surface.

Jan 1, 1962

By Terry Matts, Bruce Ripley, Clark Fletcher, Paul Rapp, Stan Holtby, Jim Dent

The Stave Falls Project of BC Hydro, situated 65km east of Vancouver, BC, Canada, involved the construction of a new two-unit 9OMW hydro-electric facility to replace an existing powerhouse. The final phase of the intake excavation consisted of a plug blast to break the channel through into Stave Lake. The plug consisted of a rock and till wall topped with a fill cofferdam, about 51m wide and between 8 and 12m high. Total rock volume was approximately 2600m3, overlaid with about 4600m3 of till/fill. This paper describes the methodology and practical techniques used in planning and loading the blast, and the precautions taken to protect the new and existing structures and equipment. Blasting of the plug by the normal method using downholes would have required the placing of extra fill and much drilling through casing, so the contractor made the decision to drill horizontal holes from the dry, downstream side. Because of poor rock conditions, all 183 holes had to be drilled oversize at 3.5” dia. and fitted with 2.5” id. plastic pipes to keep them open. Hole lengths ranged from 2.5 to 18rn, with a pattern of 1.5m spacing and l.Om burden (with the holes slightly fanned vertically). Because of significant water exposure, a film-packaged emulsion explosive was used, placed using a pneumatic cartridge loader for maximum borehole compaction. The powder factor averaged 1.3kg/m3 (2.21bs/yd3, rock only). An initiation system of combination surface/downhole delay shocktube units was employed, with double and triple redundancy. The maximum number of holes firing in any 8ms window was limited to three (to minimize vibration), while the whole sequence was fully activated before the first hole fired. All shocktube connections were secured and covered over at the foot of the rockface before flooding the excavation downstream of the plug prior to the shot, To protect the powerhouse gates from hydraulic shock, all hole collars were grouted and an air curtain was provided. The blast was completely successful. A maximum vertical displacement of 6m was recorded, but no flyrock was evident. Readings for peak over-pressure and vibration were well below the allowed limits. Mucking proved to be easy, with fine fragmentation, full pull, and no tights.

Jan 1, 2000

By F. Burat

Large reserves of feldspar ore exist in the Aegean region of Turkey. The main colored impurities in these ores are iron- and titanium-bearing minerals such as anatase, rutile, sphene and ilmenite. In this study, a potassium feldspar ore containing mainly quartz and coloring impurities was subjected to beneficiation tests involving magnetic separation and flotation, which were applied either separately or in combination. Bench-scale flotation experiments using cationic collectors G-TAP and Flotigam V-4343 and using HF and H2SO4 as modifiers were employed to separate feldspar from quartz and to remove part of the titanium impurities. The best results were achieved with a combination of high-intensity wet magnetic separation and flotation. A feldspar concentrate containing 16.28% Al2O3, 10.75% K2O, 2.84% Na2O, 69.97% SiO2 and 0.16% Fe2O3 was produced. A quartz concentrate containing 2.30% Al2O3, 0.48% K2O, 0.42% Na2O, 0.07% Fe2O3 and 96.20% SiO2 was also obtained

Jan 1, 2007

James Barnes is Managing Director of James Barnes & Associated Ltd which is a company that has invested ten years of development to provide developers with a transparent, user friendly consultation framework that identifies who needs to be consulted, how they are to be consulted and procedures required to manage the risks associated with getting all the wrong! Despite the assertion above, this paper is not about to provide delegates with the answer to whom they ought to consult or identify the expectations that Maori might have in regard to the consultation process. It would be a very brave person indeed who would venture an opinion on such a sensitive subject. There are no short cuts to finding out what expectations Maori might have on any given situation. Nothing can be taken for granted. What this paper will attempt to do however is provide practical insights into what might be on the minds of Maori interests as they deal with the issues associated with mineral resources, particularly those under Treaty of Waitangi Claim. The Treaty of Waitangi has a significant bearing on the current debate between Maori and the Crown regarding ownership of mineral resources in New Zealand. The Waitangi Tribunal is currently hearing a case presented by a number of Iwi over the ownership of oil and gas resources in Taranaki and Hawkes Bay. Others will follow. The Crown and Maori have never been able to settle differences over ownership rights without resorting to legal action and it looks like this scenario is about to be repeated in regards to minerals. The Crown has a duty to actively protect the Maori interest. This is a fundamental expectation in the relationship between Maori and the Crown. In the case of minerals, Maori have yet to see the Crown do its duty. The impact on developers has become evident through Maori objections to consent applications as the issues of mineral right remain unresolved.

Jan 1, 2000

By Adilson Curi

"A fundamental aspect in the development of any open-pit mining project is the determination of the mineable mineral reserves, obtained with the design of the so-called ultimate pit limits. In this paper, firstly the Vulcan software applied over the data of MR phosphate deposit will be introduced. Modeling of the ore deposit has been done by geostatistical and conventional methods by using geological data of 41 diamond core samples. Insitu geological reserves were estimated to a level of accuracy to support detailed mine planning. Ore body has been divided into regular three dimensional fixed blocks. The ultimate pit limits of the model deposit weredetermined by the vulcan program by an optimizing technique. Additionally, the approximate location of the deposit and drillholles and the contour map of the ultimate pit limits generated by the vulcan program are presented. "

Jul 17, 2000

By Peter Swanson

One of the primary methods for analyzing roof stability in underground mines is the age-old method of “roof sounding” where a miner taps on the roof and listens for the hollow sound of loose blocks of rock. This paper looks at the feasibility of using noncontact laser-based vibration measurements to detect roof fall hazards with the ultimate vision of improving, expanding and automating procedures for mine roof inspection. Vibration measurements made on loose blocks of rock in underground mines are summarized and compared to estimates of fundamental resonance frequencies for rock slabs of the size responsible for highly hazardous “skin failures.” Both laser Doppler vibrometry and full-field interferometric methods are examined and are considered to be feasible methods for detecting anomalous vibrations in loose roof rocks. Results from simple laboratory experiments using laser vibrometry demonstrate some of the proposed application concepts. While considered a challenge to move these techniques from the laboratory to heavy industrial or outdoor environments, the potential for success in the current application is enhanced by the reduced requirements of qualitative analyses.

By Gary Kuhns

Central Florida is among the fastest growing urban areas in the United States, and its rapid development has required the steady construction of various types of civil engineering works. The karst geologic terrain and variable geotechnical conditions, however, present special challenges to the design and construction of deep foundations. The subsurface profile can be idealized as a surficial layer of Pleistocene sands, underlain by the highly variable Miocene-age Hawthorn Group, consisting of various combinations of sand, silt, clay, phosphate and highly weathered limestone. The Hawthorn Group is underlain by Eocene-age limestone that comprises the Floridan aquifer. Vast networks of solution cavities are present throughout the Eocene limestone, sometimes allowing downward raveling of the overlying soils and the creation of sinkholes. In some cases, the relic sinkholes can be filled with soft compressible organic soils extending to depths greater than 100 feet (30.5 m). Driven piles are frequently employed as a deep foundation alternative, although occasionally cast-in-place piles/shafts have also been used. Piles are often driven for bearing in the weathered limestone within the Hawthorn Group, but are sometimes installed as friction piles in the upper soil and intermediate geomaterials. Dynamic pile testing is routinely performed during pre-construction test pile programs, or during production for quality control and assurance purposes. This paper presents discussions on the design and construction aspects of deep foundations unique to Central Florida subsurface conditions and local practice. Foundation issues such as subsurface variability, soil setup, pile damage, negative skin friction, and sinkhole conditions are discussed with the aid of demonstrative case histories.

Jan 1, 2003

By Sam X. Yao

The underwater concrete technology has historically evolved largely through a trial-and-error process of constructing marine works. Many outstanding examples exist of high quality concrete placed underwater. However, failures also occurred and led to excessive cost and/or schedule overruns. These failures were largely due to improper concrete mix design or improper placement. The problems may have occurred because proper underwater concrete construction techniques and experience have not been widely disseminated. This section focuses on technical issues of underwater concrete mix design, concrete production and placement, and quality control.

Jan 1, 2013

By O. C. Blade

In its general study of crude petroleum, the Bureau of Mines has published several reports that include analyses of samples of crude petroleum from Oklahoma fields3/. This report discusses briefly the properties of crude oil samples collects in come of the major producing Yields in the State. ACKNOWLEDGMENTS This investigation was conducted by the Bureau of Mines in cooperation with the State of Oklahoma. The study was via e under the general supervision of R. A Cattell, chief engineer, petroleum and Natural-Gas Division, Bureau of Mines, Whishington, D. C., and N. A. C. Pith, supervising engineer, Petroleum Experiment Station, Bureau of Mines, Bartlesville, Okla., and. Under the direct supervision of Ludwig Schmidt, senior petroleum engineer, Bureau of Mines, Bartlesville, Okla.

Jan 1, 1939

By O. C. Blade

[In its general study of crude petroleum, tic Bureau of Mines has published several reports that include analyses of samples of crude petroleum from Oklahoma fields3/. This report discusses briefly the properties of crude oil samples collects in come of the producing fields in the State ACKNOWLEDGMENTS This investigation was conducted by the Bureau of Mines in cooperation with the State of Oklahoma. No study was made under the general supervision of R. A Cattell, chief engineer, petroleum and Natural-Gas Division, Bureau of Mines Washington, D. C., and N. A. C. Smith, supervising engineer, Experiment Station, Bureau of Mines, Bartlesville, Okla., and under the direct supervision of Ludwig Schmidt senior petroleum engineer Bureau of Mines, Bartlesville, Okla.]

Jan 1, 1939

By T. Bertke

This document assesses the environmental aspects of a preliminary design for processing kaolin clay as the domestic resource for recovery of alumina by a hydrochloric acid leach-HCl gas induced crystallization process. The report covers waste sources, control measures, and potential environmental and health effects applicable to the process technology.

Jan 1, 1980

By Victor R. Spironello

Applications of three experimental design techniques to smelting operations are explained. The report describes a factorial design using three variables at two levels, a fractional factorial design which investigates seven variables, and response-surface methodology for optimization of electric- furnace smelting processes. These methods may be applied with a minimum of trials and at little expense. Further, the writer knows of no reasons why the same methods could not be applied to other operations as well, such as steelmaking.

Jan 1, 1970