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By S. M. Spottiswoode

The aim of the hybrid location method is to improve seismic event locations by reducing the effects of errors in the wave velocity of ray paths between each event and each recording site. We report on further enhancements made to the hybrid location algorithm, which is based on the double-difference method developed by Spottiswoode and Milev1and Waldhauser and Ellsworth2. The term ?double-difference? refers to the residuals between the observed and theoretical travel-time differences and are obtained using either picked arrival times or various measures of time differences obtained from waveform pairs. These residuals are minimized for pairs of earthquakes at each station while linking together all observed event-station pairs. An important enhancement is that the double-difference term uses the median arrival time residuals to reduce the effect of outliers on the system of equations. In addition, the hybrid locations are further constrained by considering events of known locations, in this case along lines of development blasts. We relocated some 20 000 previously located seismic events in the Driefontein 5E area; 5 800 of these events were considered to have been development blasts and we constrained their locations to lie on the straight lines joining about 2 150 survey pegs from the mine?s database. Relocated events were shown to distribute more closely around advancing faces than had been the case before relocation. Wave velocities from the development blasts show evidence of anisotropy.

Jan 1, 2005

By William W. Odell

Certain gas-making processes are in use in Europe, particularly in Germany, which differ radically from those in common use in America. A number of them are of particular interest because they are different. The questions naturally arise: Are any of them applicable to the making of gas in this country and, if so, with what particular type of solid fuel? It is a fact that some of them were developed with consideration of a particular set of conditions and for the utilization of solid fuels available in Germany. The latter fuels, in certain characteristics, are unlike the high-rank fuels commonly used for making gas in the United States; therefore, in attempting to evaluate the various foreign- developed processes with regard to usefulness here, one must give attention to the particular conditions that will prevail in any specified case and also the characteristics and requirements of the process and generator under considera- tion. Three of the processes that were developed and put into commercial operation in Germany, and which have some characteristics in common, are con- sidered in particular in this publication; they are: 1. Lurgi pressure gasification process. 2. Winkler process. 3. The Leuna slagging-type producer-gas process. Each of these processes requires steam and oxygen as gas-maiding fluids. For a number of years, oxygen, has been used in a relatively pure state,. along with steam, in making gas in Germany, and many of the difficulties initi-. ally encountered have been overcome. Although it appears that oxygen recovered from air was first used in this manner as a method of utilizing a byproduct in a plant that used the nitrogen complement in the manufacture of ammonia; more recently, the oxygen was made particularly for the purpose. The fuels - brown coal or lignite used in processes 1 and 2 were not suitable for use in the older and commonly used intermittent-type water-gas generators, and it was necessary, therefore, to devise a different process for gasifying them. A gas of higher heating value than producer gas, was desired, and the use of oxygen (not air) along with steam made possible the production of the desired gas without nitrogen dilution, which characterizes producer gas. Operating data presented herein are based upon observations by, members of the Technical Oil Mission at plants in Germany, on records, and on information vocally given to members of the lässion, including the author, while visiting those plants, and they are believed to be reasonably correct; however, certain hasic observations, comparisons, and conclusions are. made by the author.

Nov 1, 1947

By Bruce Vandenberg

A 3D, PC based computer program is currently under development by Blasting Analysis International, Inc., to analyze the kinetics of full scale blasts with two or more high-speed motion picture cameras.

Jan 1, 1990

By James Scott

Outline Deposit Overview and Brief History ?Geologic Setting ?Local Geology ?Petrography ?Geochemistry ?Mineralization ?Geochronology ?Conclusions Deposit Overview ?Porphyry Cu-Mo-Au ?Discovered 1957 (BIK Syndicate) ?Various programs, most significant: ?Hecla(1970s) ?Teck(Late 1970s Early 1980s) ?Copper Fox Metals (2005 -Ongoing ?optioned from TeckComincoin 2002) ?Measured and Indicated Resources: ?847Mt grading: ?0.292% Cu ?0.019% Mo ?0.202g/t Au ?1.796g/t Ag ?Total ~ 0.485 % Cu Eq.

May 1, 2006

By G. S. Camm

Gwynfynydd is a small, high-grade black shale-hosted vein-gold deposit. The Chidlaw Link Zone is the only area being mined and contains 24 000 t ore grading 15.2 g/t gold. Within the Link Zone a complex vein structure occurs consisting of a mother vein up to 5 m thick and narrow (less than 0.5 m) leader veins. The former shows minor variations in dip, strike and thickness, whereas the latter show marked changes in all three. The leader veins are hosted within the footwall zone of the mother vein and both are composed of quartz with galena, sphalerite, chalcopyrite, pyrite and minor arsenopyrite. The vein system is transected by a series of cross-vein and intra-vein dip-slip faults. Pockets of gold occur at vein intersections or branches and within the complex footwall zone and are often related to variations in vein attitude and/or geometry. The Chidlaw Link Zone displays a complex, erratic distribution of gold mineralisation and a multi-stage history of structural activity, fluid flow and mineral deposition

Jun 18, 1905

By G. L. Oldwright, F. K. Shelton, W. E. Keck

"INTRODUCTION Zinc must be of high grade to satisfy the present demand. Even when the amount of premium paid is small, the purer metal as the buyers' preference. The following specifications for spelter were taken from the American Society for Testing Materials for 1927, Part I, pane 524. (The specifications for 1930, p. 582, are tile same.)Another specification for zinc of a much higher grade than any of the above has been established lately by the same society. The committee on zinc die-casting (Proc. Am. Soc. Test. Mat., vol. 31, 1931, p. 263) reached the following, conclusions: I. ""That the purest of zinc is necessary to produce stable zinc-base die castings, and as a result requested specifications for zinc spelter .with total impurities not over 0.02 percent."" Their tests showed that the die castings made of the purest zinc had the least elongation and the greatest tensile strength, and exhibited the least changes with temperature.Still more far-reaching claims are made for the properties of zinc containing over 99.99 percent metal. Zinc foil, for instance, may someday be made as a common commercial product. It would seem likely that the demand for zinc of high grades rill continue and that even purer varieties may be desired. This demand fits in with the modern trend in manufacturing plants of reducing the number of variables to a minimum by using pure materials, and of controlling the processing of metals during their various stages of fabrication by mechanical means instead of by expert laborers."

Jun 1, 1933

The construction of the pipeline was completed in June 1956 and the line placed into operation in December 1956, ie. it has now been in continuous operation for approximately three years under an operating pressure of up to 350 lb. p.s.i.In reviewing the operating experiences of the line we must consider three major factors, which are:(a) The effectiveness to date of the protective methods for prevention of corrosion of the pipeline, ie. the preservation of the asset.(b) The maintenance of the line in regard to interference as to its stability which could be occasioned by erosion of the line, land-slides, accidental interference by the public, or construction authorities, etc.(c) The operating techniques employed.PROTECTIVE METHODS OF THE PIPELINESo to permit a clearer appreciation of the effectiveness of the protection of the! steel pipe against corrosion, I will briefly describe the methods used in the construction of the line.The line, which is 18 in. O.D. by %6 in. thickness steel pipe, is located approximately It miles south of the main Melbourne/Gippsland electrified railway.The steel from which the pipe was manufactured conforms to ASA.A33-1937 with the following modifications.Minimum elongation on a 2 in. test specimen...

Jan 1, 1960

By B. Meddings, O. J. I. Evans

"This paper is mainly concerned with the present and probable future role of hydrometallurgy in the production of base metals.The economic and technological bases of the hydro-metallurgical plants built and operative in the mid-fifties are compared to those in production in the mid-sixties. The trends observed are extrapolated and some estimates made concerning the probable size and type of hydrometallurgical plants which will be operative in the mid-seventies.The impact of emerging socio-economic factors such as pollution control and the market demand for specialized metal products which favour hydrometallurgical recovery processes are also discussed."

Jan 1, 1971

The following notes apply more especially to the purchase of silverlead ores produced in the neighbourhood of Zeehan and Dundas; for it is this class of ore that is principally mined in those parts, and which creates competition among the ore buyers.In the early days of this field, most of the ore passed through the hands of the first buyer who had sufficient enterprise to establish himself at Zeehan but in more recent times, competition has been so keen that there are generally three or four buyers tendering. lf the output was large this would not matter so much from the buyers' point of view but when we consider that the output of the field is only some 1,650 tons per month, and that of this 70 odd tons are produced by the Western and Montana mines, aud being sent home for realization, is withdrawn from local purchasers, there is really not enough for four buyers, especially at the present exorbitant prices they pay the miners.Some of the mines have a fixed sampling day, on which it is tacitly understood that the ore buyers will attend. Others, such as Grubb's Silver Mining Oompany, No-Liability, send round a printed reminder, stating the quantity of ore, and the date of sampling.

By A. C. Fieldner

"INTRODUCTION In a previous report3 prepared for the American Gas Association, the influence of washing coal on coke properties and on gas and by-product yields was discussed on the basis of answers to questionnaires sent to coke-oven superintendents and a review of the literature on the subject. This review indicated that the elimination of free impurities by cleaning coal improved coke quality by (a) reducing ash and sulphur, (b) decreasing clinker trouble in burning the coke, (c) diminishing cross fractures in the coke, resulting in greater resistance to breakage on handling, and less small coke and breeze, and (d) greater uniformity in chemical composition and physical properties of coke. Washing also reduced the sulphur in coke and gas and increased the yield of gas and by-products per ton of dry coal charged.This paper is supplementary to the previous report and presents some experimental data obtained with Pittsburgh bed coal from Pennsylvania and Mary Lee bed coal from Alabama.ACKNOWLEDGMENTSGrateful acknowledgment is made to F. J. Pfluke, of the Rochester Gas and Electric Cc., of Rochester, N. Y., for the plant test data on screened lump and washed coal; and to Ray W. Arms, Manager of the Coal Cleaning Department, of Roberts & Schaefer Co., of Chicago, for the data on effect of air cleaning."

May 1, 1931

By George S. Rice

In response to numerous requests for information as to the status of internal-combustion mine locomotives of the Diesel type that use heavy or non- volatile oil for fuel, with special reference to their safe use in coal mines, the United States Bureau of Mines is issuing this report. Data mere obtained, on application of such locomotives to cod mining only in Belgium, France, Germany, and Great Britain. The locomotives are used in coal mining in other countries, as well as in potash, iron, and other kinds of mining, but their chief development has been in coal mining in Germany, France, and Belgium. Recently popular interest in the Diesel type of engine for motive purposes was aroused in this country by the successful application of Diesel engines to railroad locomotives hauling fast transcontinental trains, and, according to published statements, at a low cost of fuel per mile of run.

Jan 1, 1936

By F. D. Fox

The Flambeau and Ridgeway Mines, both owned and operated by wholly owned subsidiaries of Kennecott Minerals Company, were located very close to populated areas having initial concerns about health, safety and the environment. The success of both operations depended upon developing a framework of community support and enhancing sustainable development opportunities throughout the entire life cycle of the mining operations to address these concerns. The protection of the Flambeau River was the cornerstone of the Flambeau Mine’s success. The highest priority for the Ridgeway Mine was to ensure long-term physical, chemical and ecological stability of the reclaimed mine site. Both of these goals have been achieved and are discussed in this paper, which highlights Kennecott Minerals Company’s integration of sustainable development principles into its business decision-making and management processes.

Jan 1, 2003

By L. D. Gent

This report reviews the current state of the art of remote control techniques for underground continuous miners. A delineation of aspects requiring additional data is presented. Also a summary and delineation are presented in overview form for the related section functions: roof control, haulage, ventilation, power supply and rock dusting. The automated remotely controlled continuous miner project is a long-range research effort. However, the program has been divided into intermediate steps resulting in incremental production increases throughout the program. Data are developed relating the impact of our proposed research and development accomplishments to potential productivity impact.

Jan 1, 1975

This paper evaluates the effect of longwall mining on a cluster of unconventional shale gas wells located in a district barrier pillar between a current longwall panel and the future panel north of the barrier pillar. A cluster of 19 unconventional shale gas wells have been drilled and 5 additional gas wells have been proposed in the barrier pillar. The closest gas well is 25.6 m (84 ft) to the current panel tailgate and 26.2 m (86 ft) to the tailgate of the future panel north of the barrier pillar. The rib-to-rib width of the barrier pillar is 57.9 m (190 ft). The distance between the two gas wells across the barrier pillar is 6.1 m (20 ft). The pillars in the current tailgate are on 22.9-m (75-ft) and 32.0-m (105-ft) centers, and the pillars in the tailgate of the panel north of the barrier will be on 22.9-m (75- ft) and 36.6-m (120-ft) centers. The two longwall panels adjacent to the barrier pillar are 475.5-m (1,560-ft) wide. The overburden depth at the shale gas well site is 321.6 m (1,055 ft). The wells have been installed in the barrier pillar, and the current district panel and subsequently the panel north of the barrier will be developed and retreated in the near future. The average min

Jan 7, 2020

This paper briefly describes the shaft, including sinking, steel sets and their installation, shaft equipment and winders.INTRODUCTIONThe New Broken Hill Consolidated Ltd. Service Shaft is a vertical concrete-lined circular shaft, 20 ft. in diameter with -steel sets spaced at 12-ft. centres. The diameter of 20 ft. was established as the minimum that would enable the shaft both to house the proposed hoisting and service equipment and to satisfy ventilation requirements as a downcast airway. The 12-ft. set spacing was based on South African practice in similar types of shafts.The shaft extends from the surface to 28 ft. below No. 22 Level, a total depth of 3,194 ft. Sinking was commenced in September 1946, and equipping completed in January 1955. Initially the shaft was sunk and concrete-lined to a depth of 52 ft., using a stiff-legged crane and clam-shell grab for mucking. Operations were suspended at this depth to allow the installation of the steel sinking head-frame, winders and ancillary equipment.Sinking and concreting were recommenced after four months and continued to a depth of 1,035 ft. 6 in., where the shaft connected with a pilot opening. The concrete lining was poured as sinking progressed and was piped from the surface to this depth, after which all concrete was lowered in buckets and discharged through a distributor suspended in the shaft. A cycle of stripping to the pilot opening and concreting was continued until the shaft reached No. 22 Level. From this level the remaining 28 ft. was sunk full size. All plats were cut and concreted as sinking progressed.

Jan 1, 1957

By M. Onifade, O. S. Otuogbai, A. F. Mulaba-Bafubiandi, O. D. Eniowo, H. Grobler

Artisanal and small-scale miners in Nigeria struggle to attract formal financing to upgrade their operations to a more sustainable form of small-scale mining operation. Literature shows that for an investment to attract formal sources of financing; the business must be considered creditworthy by potential lenders. This means that the credit risks associated with the investment must be bearable for the potential lender. This study looks at how artisanal and small-scale miners can attract formal funding, which will help them take the leap from artisanal state to a form of sustainable small-scale mining operation. This study evaluates the creditworthiness of artisanal and small-scale mining operators using key credit risk parameters identified in the literature and through primary investigation. A quantitative study is conducted on a sample of 100 artisanal and small-scale miner establishments in Nigeria to evaluate the effect of these identified credit risk parameters on creditworthiness. It is shown in this study that being a member of a mining cooperative society, which is a form of social collateral, best improves the chances of access to formal financing for miners within the sample group. This underpins the role of social collateral, in both the formal and informal economy, and its influence in improving the creditworthiness of a typical artisanal and small-scale miner.

Jul 23, 2025

By M. Hagfors

When establishing an underwater testing site for the energy measurements of the explosives, the dimensions of the measuring pool have to be measured to find out what is the maximum weight for the test charge. Secondly one has to decide the distance between the pressure gauge and the shooting point. Thirdly the pool has to be calibrated because of the reflections of the explosions by measuring the bubble periods of the calibration charges. The calibration shots can also be used to estimate the minimum weight of the explosive charge for the reliable energy measurements by calculating the shock, gas heave and total energy values and their standard deviations.

Jan 1, 2007

By H. J. McQueen

ORDER OF PRESENTATION ?INTRODUCTION TO THE VICTORIA BRIDGE ?REASONS FOR A BRIDGE AT MONTREAL ?RAILROAD BRIDGE REQUIREMENTS ?IRON PRODUCTION CANADA / WORLD AL ?METALLURGICAL INDUSTRY CANADA ?FAIRBAIRN, STEPHENSON SHIP PLATE-RIB BOX GIRDER ?VICTORIA BRIDGE (PREFABRICATED BRITAIN) ?IRON ORE SITUATION THE VICTORIA BRIDGE 1859, TUBULAR -WROUGHT IRON* 1898, TRUSS ?STEEL* (*HOT RIVETED) 1957, SPUR, LIFT SPANS ??DUCTILE WROUGHT IRON WITHSTANDS FATIGUE ?TO KEEP THE TRAINS ON TIME & ON TRACK? ??IMMOVABLE SHARP PIERS SPLIT ?THE IRRESISTIBLE ICE, STOPPED CITY FLOODS? ? ?********* ??111 YEARS-YOUNG STEEL TRUSS, (1898): ?STILL VITAL SEA-T0-SEA RAIL LINK? ? ?********* ??51 YEARS HAVE PASSED SINCE SEAWAY (1958) ?SWITCHED BRIDGE INTO DOUBLE LIFT SPANS?

May 1, 2011

By Brijes Mishra

This paper presents a correlation of acoustic emission (A.E.) with physical and mechanical properties of different types of rock and coal specimens which were tested under aegis of a consultancy project from a Columbian Mining Company. In this study, three types of rocks which are sandstone (Arneisca), siltstone (Arciolita) and claystone (Limolita) and two different types of coal were tested. The tests were carried out under constant loading rates according to ASTM Standards for determining Young?s Modulus and Poisson?s Ratio. In both cases a MTS electro-hydraulic loading system was used. Mode of failure in each material was characterized by the acoustic emission and the results were substantiated by the deformation characteristics of the materials during failure.

Jan 1, 2006

By Peter Cain

Longwall extraction in the Phalen Scam in the Sydney Coalfield of Nova Scotia is carried out under flooded abandoned workings in the Harbour Seam 140 m above, and at depth of up to 700 m beneath the Atlantic Ocean. Careful planning of panel and pillar dimensions is necessary to prevent inflows from the overlying workings and to prevent the development of excessive subsidence strains at the seabed. This paper briefly summarises the research undertaken over the past five years by CBDC and CBCRL into the problems associated with mining under water, and then describes the development and application of a design/planning code of practice developed jointly by CBDC, CBCRL and mine regulatory agencies. The design method employed in the Code of Practise is based on empirical data from the coalfield and parameters developed from subsidence modelling and previous water inflow experience. It includes precautionary measures to be adopted during development and mining, and monitoring procedures to be followed. It is flexible enough to allow future developments in the understanding of inflow mechanisms to be incoporated without major modifications, and represents a major step forward in reducing the potential hazards associated with coal extraction in the coalfield.

Jan 1, 1996