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Synthetic hollow microspheres have demonstrated reliable sensitization and detonation characteristics in industrial explosives for almost two decades. During that time, water gel formulations and use conditions have changed. The introduction of emulsion explosives has also dictated technical improvements in microsphere sensitizers. In contrast to microspheres, gassing or other sensitizing techniques often cannot satisfy the manufacturing and blasting characteristics required of today's explosives. This paper discusses the sensitizing properties of microspheres, formulating guidelines and quality considerations. Packaging, sampling, transfer, metering, mixing and pumping information is also provided.

Jan 1, 1990

By T. M. Waterland

A GREAT deal of work has been done at Britannia during the past three years in improving and standardizing rounds for development headings, and the results obtained have been very gratifying. The round which has recently been adopted as a standard for all drifts and cross-cuts has, in some instances, doubled the average length of break formerly obtained. It has also increased the footage of advance per labour shift and reduced explosives' consumption. At the present time, with a shortage of skilled labour, more control is necessar7 in directing the drilling of rounds. The use of a standard round has been o great assistance to the foremen and shiftbosses. NATURE OF GROUND Most of the ground encountered consists of a moderately silicified chlorite schist, known locally as G.M.S (green-mottled schist). It cannot be termed hard ground, because a three and one-half inch Leyner will drill at an average rate of twelve inches per minute. Due to the abrasive nature of the ground, the gauge of the steel wears rapidly and in most cases one set of steel is needed for each hole. The ground is not 'free breaking and holes must be spaced correctly to obtain a maximum break. DEVELOPMENT OF STANDARD ROUND FOR THREE-SHIFT OPERATION Late in 1940, a development programme was started involving 7,000 feet of drifting, 6 ft. By 7 1/2 ft. In cross-section, in two headings. Plans were drawn up to advance the headings on three shifts. Equipment used in the headings was as follows: D.A.35 Leyner?machines, Eimco Model 12B mucking machines, nine one-ton end-dump cars, one Mancha Little Trammer on the longest heading, 20-pound rail, 4-in. 15 compressed-air line, 15-in. Fan pipe connected to 5 h. P. Coppus fan. Diamond-drill cross-cuts, 16 feet in length, were cut every 250 feet. Switches were installed at these cross-cuts and they served as passing points for the cars. One siding seventy feet in length was cut in each heading at approximately the half-way point. The cycle of operations planned was to muck out, drill, and blast each shift. Previous performance in this type of ground indicated that a daily advance of 12 feet to 14 feet might be made. However, if a better type of round could be developed, an increased daily advance would be possible. A study of the time available for each operation in a net working shift of six and one-half hours indicated that the maximum depth of round that could be mucked, drilled, and blasted each shift would be six and one-half feet. When this maximum depth was decided upon, the next problem was to develop a satisfactory round. Due to ventilation difficulties and to the short net working shift, the whole round had to be blasted at one time. In other words, no blasting of the cut-holes could be done.

Jan 1, 1942

By B. K. Ayres

Modern management of uranium mine or mill waste storage facilities (WSFs) often requires that they be remediated or decommissioned with a cover system. In addition to creating a self-sustaining landscape that supports the end land use, cover systems are intended to reduce long-term risks to human and ecological receptors from the stored waste to acceptable levels. The performance and longevity of a cover system will be strongly influenced by the features or shapes of the WSF final landform. Hence, cover systems and landforms must be thought of as an integrated design. Based on the author’s experience, the most important elements of the design process for maximizing the potential of WSF final landforms / cover systems being sustainable over the long term are noted in this manuscript. Several key items that must be considered and addressed during the planning phase of constructing a WSF final landform are also described. Various methods for monitoring performance of a WSF final landform are also reviewed. Key aspects associated with decommissioning a tailings WSF and waste rock pile at the former Cluff Lake uranium mine in northern Saskatchewan are included to illustrate many of the practical insights provided in this paper.

Jan 1, 2020

By John P. Turner, Steven S. Dapp, Dan A. Brown

"The Goethals Bridge Replacement (GBR) spanning the Arthur Kill Waterway between Elizabeth, NJ and Staten Island, NY consists of a dual-span 1,982.5-ft long cable-stayed bridge with approach spans of 2,545 ft on the NJ side and 2,788 ft on the NY side. The bridge is supported on over 200 drilled shaft foundations ranging in diameter from 4.5 ft to 10 ft and socketed into Passaic Formation siltstone. Drilled shaft resistances for design were based on load tests as described in a companion paper (Dapp et al. 2016). This paper presents the main foundation design considerations and challenges. The approach to construction of the rock sockets, with a focus on quality in order to support the use of high nominal values of side and base resistance, is described. Lessons learned from this project and their application to future similar projects are presented.INTRODUCTION AND BACKGROUNDThe Goethals Bridge Replacement (GBR) project is a Public-Private Partnership (P3) that represents a major milestone for the Port Authority of New York and New Jersey (PANYNJ) in its distinguished history of bridge building in the greater New York City metropolitan area. The new bridge will replace the existing Goethals Bridge, named after Major General George W. Goethals, Chief Engineer of the Panama Canal and the first consulting engineer for the Port Authority. The existing Goethals Bridge along with the Outerbridge Crossing and the Bayonne Bridge comprise the three Port Authority bridges connecting Staten Island with New Jersey. The existing Goethals Bridge and the Outerbridge Crossing are cantilever truss structures and both opened on the same day in 1928. They were designed by J.A.L. Waddell under the supervision of the eminent engineer Othmar H. Ammann (1879-1965), who was the designer of many other iconic bridges in the NY City area including the Bayonne Bridge (1931), the George Washington Bridge (1931), and the Verrazano Narrows Bridge (1964). The designer of record for the replacement Goethals Bridge is Parsons Corporation, which is the successor firm of Robinson & Steinman, whose principal David B. Steinman was also a notable NY area bridge designer and a contemporary and rival of O.H. Ammann.The replacement Goethals Bridge is supported on over 200 rock-socketed drilled shaft foundations. Each main pylon tower is supported on a group of six 9-ft diameter drilled shafts and each anchor pier is supported by two 10-ft diameter shafts. Each approach pier consists of a two-column bent with each column supported on a rock-socketed drilled shaft. A rendering of the Main Bridge crossing the Arthur Kill is shown in Fig. 1."

Jan 1, 2016

By Carter A. J, Miller D. M, Holder N. H M, Van Aswegen P C

The Harbour Lights Mine situated at Leonora in Western Australia, mines a refractory sulphidic gold ore. The main sulphide minerals are pyrite and arsenopyrite. Due to the association of gold with the pyrite and arsenopyrite, gold recovery is not amenable to the normal cyanidation process.A pyrite/arsenopyrite flotation concentrate is produced at Harbour Lights. This concentrate has been stockpiled for the past two years.A bio-oxidation process (BIOX«)* to treat refractory gold flotation concentrates has been developed by GENMIN in South Africa. Harbour Lights acquired the technology from CRL BIOX« Pty Limited in Brisbane, to treat the refractory gold concentrates.

Jan 1, 1992

By Frank E. Cash, Roy G. Stott

This circular describes four modern change houses of the Lake Superior iron - ore district , all conceived and constructed since 1937. The oldest change house described herein was constructed and occupied in 1938 , yet it embodies the modern improvement of air - conditioning . The purpose of this report is to describe and illustrate improvements with regard to health and safety features combined in the construction , arrangement , ventilation , heating ,lighting , and other features , with the aid of photographs , sketches , and diagrams . The modern change house is a fire - resistant structure in which intermingling of men in mine clothes and men in street clothes , hazardous dust , heat and humidity , crowding , poor lighting , slippery and muddy floors , and inadequate facilities for clothes and for bathing have been largely eliminated . The miner coming off shift at a modern mine no longer faces the elements when he gets off the cage . He travels through a tunnel to the change house , where he is cooled gradually by room temperatures as he passes from the mineclothes section and shower room to the street - clothes room . He is assured of dry clothes when he is ready for them . No longer is he sent out of the change house into a muddy yard to drive away as best he can . The modern change house has an improved parking lot and graveled or concreted walkways from it to the change house entrances .

Jan 1, 1949

By William P. Diamond

In this U.S. Bureau of Mines study, production trends have been analyzed for 82 gob gas ventholes on 7 longwall panels in the Lower Kittanning Coalbed, Pennsylvania. Cumulative production from individual holes was found to vary considerably, ranging from 0.03 x 106 to 10.1 x 106 m3. Peak production rates were generally about 0.03 x 106 to 0.06 x 106 m3/d, but rates over 0.10 x 106 m3/d were observed. The variability of gas production from individual holes can be attributed to' several factors, including completion practices and problems, the extent of fracture development in the strata above the extracted panel, water production, and location on the panel. Of particular significance is hole location. Holes on the ends of the panels, where overburden strata are in tension because of the support of the surrounding pillars, were generally the highest and longest producers. This observation led to the experimental placement of gob gas ventholes in the zone of tension along the margin of a panel, instead of in the traditional centerline location, which is in compression. Analysis of 7 months of gas production data indicates that the experimental near-margin holes produced 77 pct more gas than did centerline holes on the same panel.

Jan 1, 2010

Mount Isa Mines Limited (MIM) and the Commonwealth Scientific and Industrial Research Organization (CSIRO) have, over the past 15 years, jointly developed the Isasmelt process. This process is based on the use of the Sirosmelt top-entry, submerged combustion lance, developed by the CSIRO in 1973. While the Isasmelt technology was first applied to lead smelting, it has more recently been adapted to smelt copper concentrate. A 15 t/h demonstration Copper Isasmelt plant was commissioned in MIM's Mount Isa copper smelter in April 1987. The success of the Copper Isasmelt demonstration plant, which smelted over 532,000 metric tons of copper concentrate, has led to the construction of two full-scale furnaces: a 104 t/h furnace in the Mount Isa copper smelter, and a 585,000 t/y (650,000 short t/y) furnace at the Cyprus Miami Mining Corporation smelter at Miami, Arizona. The commissioning of these furnaces commenced in August and June 1992, respectively. The MIM Copper Isasmelt furnace will raise the Mount Isa copper smelter's capacity to 265,000 t/y of copper. The plant includes several innovative features, including: Andritz pressure filters, a rotary holding furnace, and an Ahlstrom flux-flow boiler.

Jan 1, 1993

By Diego L. Romero, Joy P. Romero

"IntroductionThe purpose of this paper is to explain the theory and demonstrate the industrial applications of electrostatic separation. Wabush Mines' use of this type of processing for the concentration of iron ore is unique in the industry. Other minerals are concentrated electrostatically but the process is not widely used.Typical minerals separated by electrostatic separation techniques are:Non-ConductorsAnhydriteApatiteBariteBastnasiteBerylCalciteChrysotileCorundumDiamondEpidoteFeldsparsFluoriteGarnetGypsumHornblendeKyaniteAcmiteAugiteBrookiteCassiteriteChalcopyriteChromiteColumbiteCopperDaviditeEuxeniteFerberiteFrankliniteGalenaGoldGraphiteHematiteMica (Biotite)Mica (Muscovite)MonaziteOlivinePerovskiteQuartzScheeliteSideriteSillimaniteSpheneStauroliteSulphurTopazTourmalineXenotimeZirconConductorsIlmeniteIlmenite-( High Iron)IlvaiteKoppiteMagnetiteMarmatiteMolybdenitePyriteRutileSamarskiteSphaleriteTantaliteWolframiteWulfeniteThe limitations of this process are:1. There must be a difference in conductivity between the minerals being separated.2. The size range must not be very wide.3. The specific gravity of minerals being separated should be similar or the minerals to be pinned should be lighter. 4. The feed must be dry.5. The particle shape should be more or less uniform. 6. The feed must not be high in true middling particles."

Jan 1, 1989

By T. W. Camm

"We hear all the time about the value of hard work and perseverance, and the part they play in the professional life of successful people. What we do not hear so much about are the many professionals who work hard and persevere, yet never seem to quite reach the level of success they aim for. Some current authors are beginning to give more attention to the part luck/black swans/outliers play in success. This is not a new phenomenon, Machiavelli had a lot to say about it back in the Renaissance. So how can knowledge of this dynamic help in a modern organization? INTRODUCTION Work hard and you will succeed. Go to the right school, major in the right degree, study hard, and get a good job. Look at the lives of successful people, and do what they do. Be all that you can be. You can be anything you want to be. Really? Those who are successful always get attention, people want to know what they did to reach such a high position. Invariably, at least part of their narrative will include hard work, wise insight, taking advantage of opportunities, etc. If they are of a more generous nature, they might also allow that building the right friendships and collaborations also played a role. All of this may be true; what we do not often hear are the stories of those who did all of these very same things, but did not find success. An example from pop culture: The Voice. I have watched this show occasionally the past couple of years. One of the things I like about the show is that the initial screening of contestants is based solely on their singing voice (hence the name of the show), and not on their appearance. At the time of this writing (early November), the judges have just finished elimination rounds for their final teams to go on to the live shows. Here is my point—in almost every case the judges agonized over choosing who would go forward and who would be eliminated. And the reason is because all of them are really talented singers. It is impressive how gifted they are. At the end of each season, only one is declared a winner, out of that gifted pool of singers. When you hear their stories, they are all talented, hard-working individuals sacrificing for their art. And as far as I know, none of them has ever become a star. Hard work, dedication, sacrifice, talent—sometimes it is enough, sometimes not. I will be looking at the part uncertainty/luck/black swans play in our lives, but I want to make it clear at the beginning that I am not saying everything that happens to us is out of our hands or beyond our control. Taleb makes this same point (2007, p. 52): “This problem is chronic: if you tell people that the key to success is not always skills, they think that you are telling them that it is never skills, always luck.”"

Jan 1, 2017

By S. A. Luciani

"In 1957, an asbestos orebody was discovered in the northern sector of the Ungava Peninsula of the Province of Quebec, an area now identified as Asbestos Hill. The deposit is situated on a plateau 1700 feet above sea level and 42 miles inland from Hudson Strait. It is a bleak, iso. lated location of typical arctic environment. Fifteen years were to pass before the first shipment of ungraded fibre was made in 1972. These years we1•e occupied with field surveys and investigations, diamond drilling, engineering design, evaluation of investment and operating costs, and construction. The problems normally associated with mine development were further complicated by location, isolation, and the extreme cold and permanently frozen ground of the arctic regions. Unique to an isolated arctic operation are the organization of support facilities and services, procurement and retention of personnel, construction of access roads and airports, and scheduling of product out and supplies in during the short summer period of sea navigation."

Jan 1, 1976

By E. C. Strycula

Solid-state equipment offers a number of potential advantages in the coal mining industry. These advantages can only be realized, however, through careful and judicious design of the control and protection circuitry. Problems relating to the interaction of solid-state equipment on the electrical system and the special design considerations which apply to solid-state circuitry are examined. Design guidelines are provided for solid-state applications in the areas of: (a) equipment operated from a DC trolley wire, (b) drive systems for surface mining equipment, (c) AC motor starters, and (d) electromagnetic interference.

Jan 1, 1981

Law of the Sea. - The Ninth Session of the Law of the Sea Conference resumed July 28 at Geneva and will run for 5 weeks. The 160-nation Conference began in 1973. Two of the major factors to be discussed are the transfer of technology to the UN-controlled Enterprise or mining authority, and how the 36-member Council will make decisions. As the session completed its third week, delegates expressed little hope of completing a treaty text this year. There was a feeling, though, that substantive issues might be settled so that a treaty text can be completed next year. The Deep Seabed Hard Mineral Resources Act signed by the President on June 28, provides an interim regulatory procedure for ocean mining activities conducted by U.S. nationals that may be superseded by a law of the sea treaty.

Jan 1, 1980

By Darren Medd

Kumtor Gold Company (KGC) currently operates the 500,000 tonnes per day Kumtor open pit gold mine located in the Issyk-Kul region of the Kyrgyz Republic at an elevation of more than 4,000 m. To supplement the open-pit mill feed with high grade underground ore from outside the current pit limits, KGC started pre-production design and development of the underground mine for the SB ore zone in late 2006. The initial phase of pre-production development consists of exploration and haulage declines which, upon completion, will provide ventilation and access to the underground mine. Design and construction of these declines presented many challenges to the project team considering the mines unique location at high altitude, the limited experience with Western underground mining techniques in the Kyrgyz Republic, and the impact of the nearby Davydov glacier and resultant ground conditions. Completion of the exploration and haulage declines was undertaken jointly by KGC and mine contractor, J.S. Redpath Limited (Redpath). The initial phase of development including several ground falls provided detailed information on geotechnical ground types and conditions that were useful in determining the overall mine design and methodology for production. This paper covers the various aspects of the design and construction process of developing the declines under the glacier, minimizing the likelihood of further ground falls, and the journey of both KGC and Redpath which led to the successful breakthrough between the declines on 01 July 2012.

Aug 1, 2013

By R. H. Jefferson

This Bureau of Mines report describes a series of rapid wet chemical methods for the analysis of blast furnace slags. A "complete" analysis for total iron, manganese, silica, lime (calcium oxide), magnesia (magnesium oxide), sulfur, and mixed oxides (R203) can be routinely performed in less than 3 hours. These methods were employed as the analytical control procedures for the Bureau's experimental blast furnace operations and have been satisfactorily applied to the analysis of other slags and calcareous materials.

Jan 1, 1974

By SANDVIK WHITE

The mining industry produces approximately 4-7% of global greenhouse gas (GHG) emissions. It is fundamental for mining operations to take immediate sustainable action to actively contribute to an emissions-free future for the next generations. The mining industry has traditionally relied heavily on diesel technology and transitioning to more sustainable solutions requires change management to drive cultural acceptance and new product development. Sandvik was interested to find out the lifetime emissions of a single drill rig and to compare similar application diesel and BEV drill rigs with same use profile to each other. That led the calculation and pondering towards comparing different countries and mine sites as well

Jan 1, 2023

By R. V. Ramani, R. Stefanko

"The favorable mining conditions in the United States of America that resulted in the development of the highly productive room and pillar systems are largely disappearing. Increasing mechanization, poorer natural conditions, and greater concern for health, safety and environment gave impetus to the enactment of the Federal Coal Mine Health and Safety Act of 1969. These regulations prescribe more stringent requirements in face ventilation and mine air distribution, necessitating significant changes in existing ventilation systems. Stringent mandatory standards were applied to respirable dust control for the first time, and simultaneous control of both gas and dust has affected the face as well as primary distribution, most notably on haulage entries.The size and complexity of the present-day mining operations, and the need to evaluate various system changes in a limited time, call for scientific methods in mine planning. In this paper, the authors trace the previous applications of computers to mine ventilation planning and discuss the results of their work in applying a ventilation simulator developed at Penn State. The paper includes an analysis of current trends and suggestions for future research and development."

Jan 1, 2014

By Lake H. E.

The request to participate on your theme panel was accepted with some reluctance but indeed as an honor. My subject was outlined to cover 'Energy Resources - both nuclear and conventional' as related to your theme 'Minerals - Treasure Trove of the West'. This is indeed quite an order and I hope you will forgive me for concentrating mainly on the nuclear-uranium portion with brief references only to conventional fuels some of which will be covered in detail later in your conference. In regard to Uranium, I am speaking on the fringe of the area containing half the uranium reserves in your country and no doubt to many who are very conversant with knowledge of these resources. Nevertheless since our two countries have been very closely allied in both nuclear developments and uranium supplies I hope an exchange of information may be mutually beneficial. Concentration on the nuclear fuel resources is I hope understandable as nuclear energy is the coming source of power which will augment the rapid demand in the industrialized countries and provides hope for economic power in many of the more underdeveloped countries. The situation regarding conventional fuel resources is more widely known and their expanding future revolves around production cost reductions, research into diversified uses, plus more assurance of imports from countries less effected by international controversies determining export policies.

Jan 1, 1967

By R. G. Burdick

The problems presented by old mine workings affect both present day mining and land development. An automated method of locating these old mines from the surface using electrical resistivity techniques was de-veloped earlier under a Bureau of Mines contract. Subsequent Bureau research has refined the techniques and expanded the area of study to a variety of geologic provinces. During this research, six mining areas in the United States were in-vestigated with the Bureau's automated resistivity method. This report describes the mining areas involved and the results of the resistivity investigations, which showed a high rate of success in detecting old mines. It also describes the field measurement techniques and data analysis procedures.

Jan 1, 1986

By T Casten

Freeport IndonesiaÆs DOZ (Deep Ore Zone) mine is scheduled to commence production in the second half of 2000. The DOZ will produce 25 000 tpd using mechanised block cave mining methods and will have a number of major improvements when compared to previous block cave mines in the district. The DOZ will have an independent and improved ventilation system, a flexible and efficient truck haulage system, and a more reliable crushing and conveying system than in previous underground mines in the district. This paper will describe the mine plan, haulage, and ventilation systems, and compare them to those used in other operations in the district.

Jan 1, 2000