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By D. E. Keeley

Introduction Gunite is a mixture of sand and cement applied to any surface by being shot by compressed air through a nozzle, where it is wetted just before leaving the orifice. The mixture is transported through a hose from a machine called a 'cement-gun'(l). Guniting of rock surfaces has been standard practice at the Mcintyre Porcupine Mines, Limited, for several years. Where used on walls and backs of cross-cuts; shaft stations, and other rock openings, as an air seal, gunite has eliminated the necessity of constant scaling to keep rock from falling from these places, and, under worse conditions, it has been used in place of timber supports. This has been of definite help in reducing costs, promoting safety, and minimizing fire hazards. During the past year guniting has been quite extensively used here in the rock head-works of the new internal shaft, No. 12, sunk from the 3,875-foot level. Gunite is at present being applied to the stations of that shaft well below a mile from the surface. This paper describes the method of guniting as carried out at the McIntyre, and illustrates how, by the adoption of this process, mining problems connected with scaling and loose ground have been completely solved. It is hoped that the information presented may stimulate discussion and assist in the use of gunite in this and other mines. The guniting method of applying cement was first developed by Carl E. Akeley (2), Curator of the Field Museum, Chicago, in 1907, and was exhibited in New York at the Cement Show in 1910. The museum was located in one of the old World's Fair buildings, built of roughcast and in bad repair. Mr. Akeley, who was a man of inventive nature, set about devising means of applying cement to repair the walls. The cement-gun was the result. Mr. Akeley was a taxidermist of note, a sculptor, and also the inventor of the Akeley camera. In his work, he was in the habit of using fast setting materials to build up foundations for statues, etc.

Jan 1, 1934

APPROXIMATELY 26 percent of the total ore production to date from the largest single deposit of copper-bearing material in the world was mined during the war years, 1942 to 1945, at Chile Exporation Company's great open-pit mine at Chuquicamata, Chile. About 18 percent of the total waste removed during the life of the mine was handled in the same period. The total of ore and waste represents approximately 24 percent of the total material that has been excavated from the pit. This is more than was removed in the first fourteen years of operation from 1914 through 1927. The pit at Chuquicamata is 17/8 miles long, 1/2 mile wide, and has a present vertical extent of 817 ft between the top of the highest bench and the lowest bench being worked. However, when

Jan 1, 1948

By Thomas M. Keevin, Gregory L. Hempen, David J. Schaeffer

In an attempt to reduce the potential for fish mortality during the explosive demolition of Locks and Dam 26, Mississippi River, the U.S. Army Corps of Engineers, St. Louis District explored the use of a bubble curtain to reduce the fish kill radius of underwater explosions. Bubble curtains are walls of bubbles rising from a bottom-resting bubbler manifold supplied with compressed air. Demolition engineers have long been aware of the attenuating properties of air bubbles in water. As such, air curtains have been routinely used to protect underwater structures from damage by underwater explosive shock waves. However, their use in protecting aquatic resources during full-scale explosive demolition projects was untested.

Jan 1, 1997

By Daniel Rodríguez Hoyle

El presente texto señala una breve reseña histórica sobre el cobre, producción, exportación, consumo, reservas y su expansión mundial en el Perú durante los últimos cinco años.

Jan 1, 1968

By Herbert R. Appell

Urban refuse, cellulosic wastes, and sewage sludge have been converted to heavy oil by heating under pressure with carbon monoxide and steam. Conversions of the organic matter to oil, water, and gas have averaged near 90 percent at temperatures of 250° to 400° C and pressures of 1,500 to 5,000 psi. The yield of oil, based on the dry organic matter of the waste materials, is usually near 40 percent. This is the equivalent of more than 2 barrels of oil per ton of dry, ash-free waste material. The oil from urban refuse and cellulosic wastes has a sulfur content near 0.1 percent. This low sulfur content makes the oil from refuse a desirable source of fuel oil.

Jan 1, 1970

By P. Arell, D. Folkes

This paper presents the basics of EPA’s Hazard Ranking System (HRS), which is used to evaluate sites for possible inclusion on the Superfund National Priorities List (NPL). The paper describes the surface water, ground water, air, and soil exposure pathways and how they are applied to mining sites. Key factors contributing to the site score include the likelihood of a release, waste characteristics, and the targets for each pathway. Waste volumes, definitions of landfills versus surface impoundments, and background concentrations are of particular importance to mining and smelting sites. Because of the presence of metals, large waste volumes, and observable releases, mining and smelting sites often receive high enough scores to be proposed for the NPL based on a single path-way. Neverthess, owners and operators can take steps to reduce the risk of being scored, and to reduce the potential for high scores.

Jan 1, 2004

By W. R. Horn

"WHAT I PROPOSE TO DO is to review or report very briefly and generally on the most important subject areas of environmental concern within the mining industry and to indicate the progress being made. First, however, it seems to me both appropriate and necessary to refer to what I said in an address to the CIM Annual Western Meeting, in November 1971, in Vancouver. At that time, I tried to convey: that the awareness and alertness of this far-flung and diversified industry was sharply on the up-swing; that the knowledge of helpful technology for the abatement of pollution by water and solids was significantly increasing; that most mines were doing something about it; that many had already achieved a recycling of process water to a really significant extent; that progress was being made - though not without considerable difficulty - on the large-scale neutralization and subsequent chemical treatment of acid- and metals-bearing waters; that increasing work was being done by individual mining companies on methods for the vegetation of completed tailings impoundments; and that it had been possible to develop a meaningful estimate of the amount of money to be spent by the industry on environmental control measures during the period 1971-75 (as much as $500,- 000,000 ) . Reference was also made at that time to the constructive work in hand toward the fixation, elimination or dispersion of sulphur from smelters and to the considerable attention which was being given by the indust(y itself toward in-plant problems, e.g., dust and noise. Finally, note was taken of the fact that the inclusion of environmental control costs in the pre-operational financial provisions of new mining operations is now established practice."

Jan 1, 1973

By Robert J. Timko

Because of leakage through and around permanent stoppings in underground mines, more air must be forced into a mine than would otherwise be required for ventilation. As power costs increase, costs resulting from air leakage add increasingly to the operating costs of mining. The Bureau of Mines evaluated four different stopping construction techniques based on the ideas that (1) airtightness could be enhanced by brushing rather than troweling on mortar sealant and that (2) modified mortars (mortars containing glass fibers and other additives for increased strength and adhesion) would improve sealing performance. Air leakage tests comparing conventional to modified stoppings were done when the stoppings were built, after 6 months, after 1 yr, and following simple maintenance. It was found that stoppings can be built and maintained better if-- The area where a stopping is to be built is properly prepared. Stoppings are constructed using the techniques devised by the Bureau. Stoppings are periodically examined for leaks. Stoppings found to be leaking, especially at the perimeters, are resealed.

Jan 1, 1983

By Ricardo Rizo Patrón

El presente texto describe el proyecto de abastecimiento del carbón como combustible a dos fábricas de cemento en el Perú. Desde hace cuatro años, la empresa Cemento Andino S. A (Junín) y Cementos Lima S.A.(Lima) investiga la posiblidad de uso del carbón como combustible en sus plantas de producción, en sustitución del petróleo que se consume en la actualidad. Para ello, dichas empresas establecieron un proyecto en 1984, donde se realizó una instalación con volumen suficiente para cubrir sus necesidades proyectadas futuras por los próximos 12 años. Así, la transformación a carbón permitirá asegurar una futura utilización del combustible líquido para el uso de otros consumidores nacionales en caso de no encontrarse nuevas reservas par la explotación.

Jul 1, 1985

By J. Brune

The need for reliable and adaptable underground mine communications has become a focal point for both the safety and logistics of a mining operation. New mine communication technology aims to connect personnel, equipment, and data together while setting up a network that can be utilized during normal operations and also in an emergency event. The Mine Improvement and New Emergency Response Act of 2006 (also known as the MINER Act) requires mine operators to establish post-accident, two-way communication between underground and surface personnel and electronic tracking for all mine personnel. Communications systems must be designed such that they can survive major mine accidents, including explosions, fires, inundations and ground falls. Typical, wire-bound communication technologies are vulnerable because wires are often destroyed in such accidents. Wireless technologies that work well on the surface, such as cellular telephone networks; have limited applicability underground because the wireless signals do not propagate through rock.

Feb 23, 2014

By Roger N. Miller

Talc mining in Vermont has in recent years undergone a progressive change in mining methods and in mining equipment. Underground mines have been phased out except in special circum- stances, and continuous mining machines (CMM?s) have replaced conventional drill/blast mining systems. Talc mining in Vermont began in the late 1800?s, and has continued without interruption to date. Beneficiation (flotation) has been applied since the early 1930?s, and has provided special products for toiletries and other markets. At the present time, there are two active companies that have evolved from the cumulative absorption of nearly ten smaller operations.

Jan 1, 1984

By C. Lambert

It has been shown that contacts between host rock and engineered barriers may be critical in the design of deep radioactive waste repositories. Water is expected to reach the interface zone after the re-saturation of the geological massive and its presence may lead to concrete leaching. Such a phenomenon could increase the interface transmissivity and compromise the confinement of radioactive waste. Recent experimental results from Buzzi et al. (2008) have enhanced how concrete leaching can drastically change the mechanical behaviour of such interfaces. Because of the local loss of strength resulting from leaching, shearing resulted in a degradation of the interface asperities. Similarly to rock joints, intact interfaces exhibit a usual contracting-dilating behaviour. On the contrary, depending on the extent of leaching, the degraded interface can display a fully contracting. This paper intends to investigate the influence of concrete leaching on the mechanical behaviour of host rock-concrete interfaces. The leaching process consists in the dissolution of some of the hydrates of the cement paste, leading to a reduction of the strength and Young's modulus. A discrete model has been developed with PFC3D where a simplified interface morphology has been introduced using a saw-tooth description of the asperities.

May 1, 2009

By D. Runnels, Daniel Roy, Ricardo Esteban, J. Torrealba-Vargas

"An intuitive way to reduce power consumption in grinding operations is to feed the grinding circuit with finer feed by enhancing blasting and fragmentation control. The optimization of blasting with the objective of minimizing power consumption in grinding is not new.The study was based on a Canadian mine that processes a very hard ore. BBA conducted blasting/fragmentation and grinding circuit surveys in 2014. The results of the exercise were used to develop a base case model to simulate the effect of blasting in the operation on the grinding circuit. Tools for fragmentation simulations, particle size measurement and crushing/grinding simulations were used with the objective of reducing the OPEX costs including power consumption.The paper describes the steps involved in the model optimization as well as an economical evaluation of the OPEX savings.INTRODUCTIONIn 2014 BBA was retained by one of its clients to conduct a crushing and grinding survey. The objective of the survey was to update the grinding circuit model with production data and also to develop a tool to investigate opportunities for process improvement.A second phase of the study involved the development of drilling and blasting and crushing models. The models were used to diagnose the operations and to investigate opportunities for process improvement.The objective of the present study is to describe the approach and to identify potential improvements to overall mine site operating costs by better integrating mining and milling operating costs with blasting and grinding models."

Jan 1, 2016

By Corinne Boone

CO2e.com, LLC - launched in November 2000 - aims to be ?the global hub for carbon commerce.? CO2e.com is a subsidiary of the Cantor Fitzgerald Group, one of the world?s leading brokerage firms Recent Investor in CO2e ? Mitsui & Co. Alliance with Cantor Fitzgerald Environmental Brokerage Services Group (CFEBS) Offices in London, Toronto, Tokyo, New York, San Francisco, Los Angeles, Connecticut, Houston Primary Goals/Benefits of ET § Goals of Emissions Trading: ? Permit Industrial Growth/Expansion ? Promote Economic Efficiency and Flexibility in Meeting Air Pollution Standards § Benefits of Emissions Trading: ? Enhance Air Quality w/o Economic Stagnation ? Encourage Development of New Technology ? Foster Most Efficient Use of a Limited Resource -- Clean Air § Contributes to Sustainable Development and objectives of UNFCCC, Kyoto Protocol?.

Nov 1, 2002

By Ronald C. Whiting

SINCE the advent of what has been aptly called "chemical flotation," about 1920, the number and complexity of the various chemicals used in practice have increased enormously. Over 300 patents have been issued dealing exclusively with flotation reagents, and many of these embrace from two or three up to a score or more of specific compounds. The exact number of compounds actually finding a practical use in flotation would be difficult to determine, though the U. S. Bureau of Mines gives an annual list by groups.

Jan 1, 1938

By Chris Ashton, Andreas Rädle, Taner Aydogmus

"The Contract C310 is part of the current biggest infrastructure project of Europe “Crossrail” which is a major new cross-London rail link project and comprises the construction of the North Woolwich Portal, Plumstead Portal and the twin tube Thames Tunnels with a length of approximately 2.6km. Two Mix-Shield TBMs (Diameter 7.12m) were driving through differing challenging ground conditions (Thanet Sand, Gravels, Flint and Chalk) below the ground water table. The two tunnels were underpassing several listed buildings, sensitive structures, operational railway tracks with low overburden and close to existing subway tunnels in an urban environment. Several additional measures as compensation grouting, micro piles and an intensive monitoring has been carried out to ensure a safe tunnelling process. PROJECT OVERVIEW CROSSRAIL Project Crossrail Crossrail is currently the biggest infrastructure project in Europe which has been developed to serve London and the southeast of England. The project includes the construction of twin-bore tunnels on a west-east alignment under central London and the upgrading of existing National Rail lines to the east and west of central London. The new rail track, as shown in Figure 1, starting in Shenfield/ Abbey Wood in the east of London and ending in Reading / Heathrow Airport in the west of London, includes the construction of nine central area stations, providing interchange with London Underground, National Rail and London Bus services, and the upgrading or renewal of existing stations outside central London.Altogether there will be 118km of new rail tracks, including 42km of tunnels and 40 train stations. After completion in 2018, Crossrail expects 200 million passengers per year (Tauriainen, Rädle, Ingram 2013)."

Jan 1, 2016

By Ignacio Agramunt, Pamela Antonioli

¿Es la actividad minera positiva o negativa para un país? La respuesta la determinará el sector mismo, en la medida en que se decida a asumir el rol de motor del crecimiento sostenible, a través de su capacidad de añadir valor, es decir, de innovar. A partir de esta premisa, los autores analizan las brechas, dificultades y posibilidades que se plantean al tratar de modificar enfoques tradicionales, bien sea en competitividad, relaciones comunitarias, o procesos de mejora interna de las empresas. Al respecto, destacan la presencia de actores como el Hub de Innovación Minera del Perú, enfocado en facilitar, articular y acompañar la implementación de este tipo de procesos en las empresas.

Jul 30, 2020

By Paul A. Rittenhouse

First of all, I want to thank John Dunlap for asking me to this AIME meeting in Denver. I was first introduced to Denver and The Rocky Mountains more than ten years ago and immediately decided it was one of the most attractive spots in the world. I've come back many times since and still welcome any opportunity to return, even if it means I have to prepare and give a paper on potash. When John Dunlap gave me this assignment, he told me that the program would include papers on the geology of potash, papers on new discovered potash deposits and new mines and asked me to discuss potash from the commercial point of view. He also asked me to include a supply/demand outlook for potash. However, one thing he did not mention was "how far into the future he wanted me to look" and it seems to me the time element is a crucial factor to you who are both geologists and miners as well as to me. In your case, you have to look far enough into the future to give you time to explore, find, evaluate, develop, and bring into production a commercial deposit. My mining associates and friends don't agree on how long that takes but it's probably somewhere in the range of eight to fifteen years. But, they all agree on one thing and that is that the time required is continually getting longer. Now my time problem is just the opposite. It is "relatively" easy, and I stress relatively, to identify and evaluate the importance of the various factors that impact on both the supply of and demand for a commodity such as potash if the time period is today. It gets a little tough if one has to project into tomorrow or next week or next month. And when we start talking in terms of a year, five years or ten or fifteen years, things really get sticky and the old crystal ball becomes mighty cloudy. But we economists and forecasters are not known for our temerity so let me get on with the job at hand and take a look at the world potash supply/demand outlook.

Jan 1, 1978

By R. C. A. Thurston

Introduction A mechanical spring has been .defined by Wahl ( 1) as 'an elastic body whose ?primary function is? to deflect or distort under load, and which recovers its original shape when released after being distorted'. Most material bodies are elastic to some extent ? and will deform under load, but they are seldom regarded as springs since this is not their primary function. The principal applications of springs are the absorption of energy and the mitigation of shock, the support cf moving masses or the isolation of vibration, and the provision or measurement of definite loads or torques. A large number of spring types have been developed to serve these purposes and to meet the different operational requirements; they range from the large semi-elliptic leaf suspension spring to the delicate watch hairspring. The springs of most importance in machine design, however, are the helical round-wire compression or tension types. They are made in a wide variety of sizes and are used in tremendous quantities, mainly because of their low cost, their compactness, and their relatively high efficiency. Their field of application is as broad as that of machine design itself, but the bulk of production is almost certainly for suspension systems of vehicles such as automobiles, freight and passenger cars, and mine cars, and it is with the last of these applications that this paper is primarily concerned.

Jan 1, 1951

By LESTER W. STRAUSS

OUR early knowledge of history and geography attracted most of us to the mineral resources of South America. The romantic tales of the Spanish activities, which were curiously alluring, and Prescott's exceptional bi-Conquest histories-Mexico and Peru-no doubt fired our minds with the .then metallic wealth of the Spanish colonies. Later developments, intensified within the past eighty years, have, however, changed its fame which now rests on such metallics as copper and tin, and among the non-metallics on nitrate of soda and petroleum. South America proper, excluding Panama, is made up of thirteen countries, a coincident parity with our original thirteen States. Its area is given as 7,231,300 square miles, or slightly less than North America (8,037,000 square miles), is made up as follows:

Jan 1, 1930