Search Documents

By M. Santillan

Minerales Monclova S.A. de C.V. (MIMOSA) has applied different methane gas drainage technologies, according to the top industry requirements in order to keep the methane gas at the lowest possible concentration in our operations, both in the development sections and longwall sections. Our staff has used the horizontal rotary technique. In 2004 MIMOSA bought a re-built drill machine and signed a contract with Resource Enterprises Inc. (REI), which included a training program in Horizontal Directional Drilling using the reflex system. The training system was developed for a period of three months in Mine VII, with very good performance by the MIMOSA staff. After the training the equipment was moved to Esmeralda Mine, where we had already drilled holes at the development section, 2,500 ft. It was the longest distance that could be reached with our original equipment, obviously; the directional drilling program is another challenge for us and our staff, but we are very confident that our result will be better every time. We will be evaluating each borehole and expect to improve our results in each progressive borehole, until we can drill up to the capacity of the equipment. We are in the process of buying another drill with an electronic monitoring device (DD DMecca) in the following months.

Jan 1, 2009

A hard lump char containing only 4 to 5 per cent ash, 0·25-0·30 per cent sulphur and a trace of phosphorus has been produced from Latrobe Valley brown coal by slow drying and carbonization of ordinary industrial briquettes at temperatures between 7000 C and 14000 C. The briquette char can be made with a variety of reactivities by varying the maximum temperature of carbonization; the higher the temperature, the lower the reactivity. The strength of the fuel compares favourably with metallurgical coke made from black coal, though it may not be quite so resistant to abrasion. Experiments in a small experimental cupola indicate that it will make a satisfactory fuel for use in iron foundries. It may also find extensive application as a smokeless fuel in other branches of industry and in household heating appliances.INTRODUCTIONVictoria, like South Australia and Western Australia, is apparently without 'significant deposits of black coal of coking quality but there are huge reserves of brown coal of high moisture content (60-66 per cent) in the Latrobe Valley (well over 20,000 million tons have been proved) and there are other important deposits in the south central portion of the State (Herman, 1952).For three decades Victorian industries, including a few metallurgical firms, have been using the briquettes made at the Yallourn factory of the State Electricity Commission of Victoria (S.E.C.). These briquettes, having a moisture content of about 15 per cent and a calorific value of approximately 9,500 B.T.U. per pound, are satisfactory for certain grate-type furnaces but they are not suitable for use in cupolas of other shaft furnaces because they disintegrate badly on rapid heating.

Jan 1, 1956

By Farrukh M. Mazhar, Philippe P. Martin

Electrical Vertical Sounding (EVS) profiling has proven to be a valuable tool to set the alignment and guide the design of a 17 km-long, 4.7m diameter water-conveyance tunnel in the Peruvian Andes at an altitude of 4,260 m. EVS profiling helped determine where to locate boreholes, and reduce the amount of drilling to 1,200 m of vertical and inclined boreholes. EVS profiling allowed the designer to identify and verify by drilling the existence of zones with difficult tunneling conditions that were avoided by realigning the tunnel. The rock quality was checked by drilling and a combined scheme of excavation by TBM and conventional drill and blast technique was developed for the final design.

Jan 1, 2003

By Susan L. Bednarz

Recent advances in digital cameras and image processing allow photographers to produce excellent high-resolution action shots in low light and high contrast conditions commonly encountered underground. Digital photography is often used for construction and inspection documentation for underground structures. Designers, owners, and contractors benefit from quality photographs that document incremental progress and project milestones. Documentation photos serve as a lasting record of as-built conditions, are an important marketing tool, and help the owner build public support for expensive public works projects. When the project is complete, the only mementos that the participants will hold onto are the photographs.

Jan 1, 2008

By J. Nakayama

For installation of round steel piles or cast-in-place pile construction through boulder contained ground or rocky formation, usual system does not function properly or impossible to work. This paper introduces an installation system which combines unique mechanism where the drill is installed on the top of a driving round steel pile or a stand pipe which is initially driven into the overburden to the depth of self-standing. When the pile driving or bore hole drilling encounters hard strata or boulder contained ground, hard material shall be crushed by the down-the-hole chiselling operated in adjustable short stroke and high frequency of blows while cuttings are discharged in reverse circulation through central reverse pipe while round steel pile is simultaneously stroked by a hydraulic hammer. The paper shall explain the mechanism of the system and introduces construction examples for bridge foundation and piled jetty.

Jan 1, 1999

By Jerald E. Harris

"Often taken for granted, drill accuracy plays a major role in the relative success or failure of a blast.Expensive technological advances in equipment capabilities, drilling tools, communications, explosives, and timing can quickly be nullified by poor drilling."

Jan 1, 1999

By N. A. Eilertsen

This paper presents the results of intermittent study begun in 1956 by the Federal Bureau of Mines of yieldable steel arches and yieldable steel ring sets installed for support of development openings in metal mines. Observations were made of this type of support in several iron mines in the northeast and north-central states. The sets, both arches and rings fabricated in the United States, are made from a hot-rolled, cold bent, structural U-shaped steel section in two weights, 15 pounds and 21 pounds per foot. The lighter section is generally used, It is 4.41 square inches in cross section area, and the calculation is that a 6-foot length of this structural shape installed as a supporting column, will safely carry the same load as a Douglas fir post of the same length but of 22 times the cross-sectional area of the steel.

Jan 1, 1962

By AIME AIME

ARRANGEMENTS for the Annual Meeting of the Institute were well advanced at the end of December as the following program will show. Heretofore this has been printed separately, but its inclusion in the Annual Review issue of MINING AND METALLURGY will, it is hoped, make it more easily available for reference until the final program is issued, which will be distributed at the meeting. Added details will appear in the February issue. Last year's meeting drew a record crowd of over 2300 which should be exceeded this year. Early reservations at the headquarters hotel, the Waldorf-Astoria, or any other convenient hotel are desirable, as are prompt reservations for the Annual Dinner. No one need worry about too much speechmaking this year, for the honors will be awarded and accepted in a few words instead of a few paragraphs, in seconds rather than minutes.

Jan 1, 1939

By Fathi Abdrabbo

Open caissons are used for many geotechnical engineering applications. Open caissons may be used as deep foundation elements bypassing weak soils to tip in firm deeper strata, and in rivers and maritime construction to reduce the risk of scour. Open caissons are also used for collecting sewage water through gravity sewer pipe networks or from sewer force mains. In such applications, the design and construction of open caissons require a detailed soil investigation program. In this way, the design and construction plan of an open caisson can be developed with full knowledge of the prevailing subsoil conditions. The engineering and construction techniques are key factors to achieve functional caissons. Based on close observations during construction stages, the current study presents some challenges that were encountered during the construction of two open caissons of internal diameters 20 m and 10 m (65.6 ft and 32.8 ft). This paper describes the procedure followed to alleviate the construction difficulties encountered. Site exploration program and control measures required to satisfy design and construction requirements are crucial aspects. Sinking of open caissons in dense or very dense sands is risky. Incorrect sinking of open caissons may cause extra cost, delay in construction, and harm to nearby structures. Air/water jetting near the cutting edge of an open caisson, outside slurry trench, and/or inside open trench may be used to drive an open caisson downward. Unsymmetrical work around an open caisson may lead to tilting of the caisson. If this occurs, the tilt should be immediately corrected before resuming the sinking process. Improper cleaning of fine materials on the caisson?s excavation bed, and/or inappropriate pouring of underwater concrete may result in a defective concrete seal. The paper contains a series of practical guidelines to assist those intending to use open caissons, and shares good caisson sinking practice with practitioners. Finally, the study aims to understand the difficulties encountered and to anticipate future problems.

Jan 1, 2012

By Eldon L. Abbott, Rebecca K. Bolan

The Florida Department of Transportation, Florida’s Turnpike Enterprise is studying the feasibility of a 1128 meter (3,700 foot) vehicular tunnel to provide direct access for Port of Miami traffic to/from I-395, I-95, SR-836 (Dolphin Expressway) and Miami International Airport. Both Bored and Immersed Tube tunnels were evaluated and re-evaluated for constructing two, two-lane, 11.9 meter (39-foot) diameter tunnels beneath the Main Shipping Channel lying between Watson Island and the Port of Miami on Dodge Island in Biscayne Bay, Miami, Florida, USA. Bedrock Geology of South Florida is predominately very permeable, vuggy limestone with sand seams and occasional voids. Groundwater inflows in deep cut-and-cover excavations, tunnel buoyancy, grouting, maintenance of Port operations and potential/possible environmental impacts to Biscayne Bay were significant issues.

Jan 1, 2005

By N. Novikov, M. Jastrzebski, N. Kryzhanovskaya, D. Shevchenko, I. Kapran, N. V. Novikov, T. Koehler, B. Zaporozhets

"The PFK FeNi Smelter was re-commissioned by Solway Resources in 2002, ending a long period of economic decline in the adjacent town. In 2009 Hatch was retained to design, supply and install a custom furnace crucible that would accommodate a capacity increase from 34 MW to 40 MW and increase campaign life through binding and cooling technologies, as part of ongoing improvement efforts. The involvement of PFK personnel was critical to the successful integration of the new furnace technology with the existing process and operational practice. The furnace upgrade project was completed in 18 months during 2010 – 2011. Since start-up, the furnace has exceeded production expectations, operating successfully at 42 MW.INTRODUCTIONAfter ceasing operations in the 1990’s, the Pobuzhsky Ferronickel Combine (PFK), located in central Ukraine, was stripped of useful equipment and deteriorated while dormant. The surrounding town experienced a period of economic decline throughout the 1990’s. Solway Industries purchased the complex in 2002 and began a systematic incremental program to re-commission the smelter using both local expertise and specialists from other parts of the former Soviet Union. This led to the re-birth of PFK as a successful toll-smelting complex, and a renaissance for the surrounding economy.As part of the continuing improvement program, PFK approached Hatch in 2009 to study the possibility of a capacity expansion from 34 MW to 40 MW. It was decided, based on the results of the study, to design and install a custom furnace crucible integrating the unique PFK FeNi process with modern Hatch furnace technology. This novel approach had many benefits, including: maximum re-use of existing furnace components (off-gas, feed equipment and transformers), minimal impact on upstream and downstream equipment and building structure, and the retention of a familiar operating regime. The latter was a key factor in the success of the project, as it allowed the extensive operating expertise of the PFK staff to remain highly relevant to the upgraded furnace. This led to minimized capital investment, a rapid start-up and no significant operational challenges switching over to the new equipment incorporating Hatch furnace technology."

Jan 1, 2012

To provide cooler air to miners working in hot areas of mines, particularly new deep hardrock mines. Approach Air supplied to hot working areas of mines is cooled by passing it through a series of water sprays. How It Works Water nozzles mounted inside a section of ventilation tubing release cooling sprays of water into the air being blown through the tube. The prototype of the water spray cooler consists of six evenly spaced water sprays located inside a 10-ft. long section of 16-inch-diameter fiberglass ventilation tubing. See diagram. This section of rigid tubing is installed into one of the positive pressure ventilation tubing lines that conduct fresh air into working stopes. The intake manifold to the six water sprays is connected to the mine?s cool water line, and the water valve on the manifold is opened. Warm ventilation air being supplied to the stope passes through the water sprays, and is cooled by the lower temperature water.

Jan 1, 1979

Once every three years the eyes of the construction and mining industry?s turn to Munich, Germany for the bauma trade fair and exhibition. From April 19-25, Messe München International (MMI) will host the 29th edition of this massive show that, despite the recent recession and global financial struggles, has grown yet again. The show, which is completely booked, will take place on a record 555,000 m2 (5.9 million sq ft) of indoor and outdoor exhibition space at the New Munich Trade Fair Centre. More than 3,000 exhibitors are expected to make use of this event. To prepare for the show that highlights some of the largest and most impressive construction and mining equipment in the world, Messe München began working months in advance on getting the infrastructure on the open-air site ready, in time for the arrival of the gigantic machinery exhibits, which started to arrive in March. Part of the preparations include a new entrance at the northwest corner of the exhibition center that was built to regulate visitor flow better. This should help with bauma considering that in 2007 more than 500,000 visitors passed through the gates. ?Although in 2010 the construction machinery sector in many markets worldwide will be recovering only slowly from the recession, we are pleased to report that we are seeing strong demand for exhibition space. This shows that exhibitors regard participation in the world?s leading trade fair bauma as a must, although many are at present having to make cuts in their advertising and trade-fair budgets. We have been particularly surprised by the strong demand for space from exhibitors from markets like China, India and Turkey. The fair is fully booked and many more companies are on the waiting list,? said Eugen Egetenmeir, managing director of Messe München. More than 50 percent of the exhibitors at bauma 2010 come from countries outside of Germany. While the show?s primary focus is on the construction section, it is not as if the mining sector will be difficult to find. With some of the largest equipment in world on display in section C2 (Fig. 1), the mining industry is sure to be well-represented.

Jan 4, 2010

By K. B. Hodgins, P. Ouellette

"The North American mining industry faces challenging emissions regulations in the coming years with the introduction of new standards for off-road diesel engines. In order to remain competitive, industry stakeholders must invest in new technologies that are economically and environmentally sustainable.Westport Innovations Inc., Vancouver,British Columbia, has developed high-pressure direct injection (HPDI) technology that allows diesel engines to run primarily on natural gas with no intrusive engine modifications while reducing emissions of nitrous oxides (NOx), particulate matter (PM), and CO2 with no loss in performance. This is accomplished through late-cycle, high-pressure direct injection of natural gas into a diesel engine combustion chamber at the end of the compression stroke. A small amount of diesel fuel is injected first to initiate combustion, followed by the natural gas fuel main injection. The diesel cycle and its operating characteristics are fully retained including high combustion efficiency, lowspeed torque, high-power output, no engine knock, and fast response to load changes. Natural gas has not been an attractive fuel alternative in mining operations due to the reduced performance associated with spark ignition engines and the added weight and space required for compressed natural gas tanks. However, liquefied natural gas (LNG) can be stored with less impact on weight and space than compressed natural gas (CNG) by virtue of its increased energy density over CNG.Westport has applied HPDI technology to the Cummins QSK series engines for high horsepower applications such as power generation and mine haul trucking. HPDI can also be applied to other engine manufacturer platforms and market applications. Westport is interested in demonstrating the unique characteristics of HPDI in mine haul trucks to show diesel performance with low emissions levels using low-cost LNG fuel.Retrofitting a Tier 1 engine with HPDI would provide emissions reductions below the EPA 2006 Tier 2 standards while maintaining the performance and efficiency of the Tier 1 platform. The longer-term target is the Blue Sky voluntary standards of 3.8 g/kW-hr (2.8 g/bhphr) of NOx + non-methane hydrocarbons (NMHC), and 0.12 g/kW-hr (0.09 g/bhp-hr) of particulate matter (PM) and future standards. Typically, an HPDI engine is capable of reducing NOx emissions by 40% over diesel operation at the same efficiency. On a mining truck meeting Tier 2 standards, this NOx reduction would translate into NOx emissions approximately 14 t per year lower than under diesel operation. PM emissions are typically reduced by some 60% with HPDI fueling, which would translate into a yearly reduction of 650 kg. Similarly, engine-out greenhouse gas (GHG) emissions are reduced by 21%, resulting in a yearly reduction of approximately 950 t per vehicle.Above those of emissions reduction, efficient natural gas usage in mine haul operations would offer significant benefits in terms of fuel cost savings, which may be further combined with monetary emission credits. HPDI technology would enable operators to exercise environmental stewardship while gaining a competitive advantage in advance of new Tier 2 and Tier 3 emissions regulations. The advantages of natural gas use among mine haul truck operations can be replicated across a broad range of engines and applications."

Jan 1, 2005

By W. K. A. Congreve

Introduction Less than a hundred years ago the engineer was able to do his job without concern for the science that underlay his practices or for the men who operated his machines. But toward the end of the last century science began to be applied to industry, and its success was such that the plant which clung to empiricism was unable to compete with the plant that followed science. Even more recently, the engineer has been forced to consider the men who operate his machines, for modern large-scale industry has given these men education, social security, and power. Hence the engineer can get good, steady labour to operate his machines only if he can offer inducements. Wages are in general outside the control of the engineer, but he is able to control working conditions. This essay is concerned with one factor of good working conditions: safety. The writer became interested in this problem during three months' summer employment as a student at the Sullivan concentrator of the Consolidated Mining and Smelting Company and was surprised at the distance his investigations led him from the field of pure engineering into the fields of psychology, education, and publicity. Nevertheless, because safety has to do with machines and with men who operate machines, and because it profoundly affects plant efficiency, it is the job of an engineer, not of a psychologist or teacher, nor of the salesman publicity expert who is often so unfortunately employed in personnel relations. The size and complexity of the subject has limited the scope of this essay to the consideration of only a few aspects of industrial safety. Considerable attention has been given to the underlying principles, but the mechanical side of accident prevention, the design of equipment, erection of guards, etc., and the very important problems of organization and administration, have not been given attention proportionate to their importance.

Jan 1, 1948

By F. M. Jenkins

Improvements in miners? safety and health, as reflected by injury and illness statistics, have reached a plateau and even been reversed. Research into miners' OSH is a necessary adjunct to regulatory enforcement. Under the National Occupational Research Agenda (NORA) mining experts have come together to draft a national agenda for this research. The Mining Sector Council, one of ten NORA Sector Councils, has produced a draft national research agenda to guide all mining research entities: academia, government, and industry. The agenda has seven major objectives, each of which has a sequence of sub-objectives: Reduce the likelihood of disasters in mines; Improve mine disaster response; Improve the health of miners; Improve atmospheric control (ventilation) in mines; Improve health and safety through behavioral research; Improve mine design, systems operations, and management performance to enhance mine health and safety; Apply ergonomics, human factor engineering, to increase health and safety. Long-term maintenance of the Mining Research Agenda requires input from the public, both here and abroad, monitoring of the impact of research results using OSH data, and partners who will translate the research to practice.

Jan 1, 2012

By Nobel Insurance Service

[Executive Director’s note: ISEE is committed to continuing its efforts to ensure that blasters be made aware of the issue of migration of carbon monoxide resulting from blasting operations. In the July/August 2001 issue of the J o u rnal we printed excerpts from “Carbon Monoxide - The Silent Hazard,” an article from the Safety Update, published by Nobel Insurance Services. We also re minded readers of the text from the 17th edition of the ISEE Blasters Handbook in its section on trench blasting as follows: “...consideration must be given to the proper venting of gases generated from the blasting. Should those gases spread laterally rather than vent directly to the surface, the gases may travel underg round and finally vent well outside of the planned area. Such events may be caused by the strata, soil conditions or root systems, or existing and/or abandoned utilities or other man-made structures. In the worst situation, gases resulting from the detonation such as CO2, CO, and/or N Ox may travel through the strata and find their way into basements of nearby homes or businesses.” While incidents are rare, a number of cases in re c e n t years have resulted from outdoor blasting operations p roducing carbon monoxide gas that has migrated t h rough the earth and accumulated in nearby enclosed spaces. T h e re are steps that a blaster can take to be proactive in preventing incidents. These steps and studies of the occurrence have been expertly presented in several papers presented at ISEE conferences and included in the ISEE Conference Proceedings, available th rough the Blasters Library. In addition, Material Safety Data Sheets provided with explosives used in surf a c e blasting should provide additional information on gases p roduced by detonation. Below, we have reprinted the IME white paper, entitled “Fumes from Blasting Operations.” The paper underscores the unique set of circumstances that combine to contribute to high concentrations of CO measurements in underground, enclosed spaces following the detonation of explosive materials and provides recommendations to blasters

Jan 1, 2004

By J Mauk, J Rowland, S Rabone

Most epithermal Au-Ag deposits in the Hauraki Goldfield are hosted in late Miocene andesites. Broken Hills is an exception, being one of the few economic deposits hosted in rhyolite. Investigation of Broken Hills provides the opportunity to collate structural data that may be compared with that collected from andesite-hosted deposits in order to evaluate the importance of rock type on vein development. The rhyolite host rock at Broken Hills is strongly flow-banded, but this anisotropy does not appear to affect the orientation of mineralised structures. There is a range of structures at Broken Hills: veins, faults, fractures, and large breccia pipes. Veins generally strike north-south, with localised changes in strike and thickness. Slip vectors determined from striations indicate near pure dipslip on the main lode, indicating an extensional tectonic setting. The orientations of vein deflections are parallel to slip vectors. This correlation is common in modern extensional fault arrays where fault growth and linkage produces subvertical deflections in fault orientation (eg TVZ). There are three main types of breccias: 1. Primary breccias related to rhyolite emplacement. 2. Jigsaw type secondary breccias that are that developed during the life of the hydrothermal system. 3. Breccia pipes. Broken Hills was a dynamic epithermal mineralising system.

Jan 1, 2003

By Euzebio De Oliveira

ONE of a recent batch of samples from the Serra da Baliza, in the state of Parana, Brazil, contained asphalt and a dark heavy oil; and workmen on the railway from Porto União to Uruguay discovered asphalt, coming from eruptives that outcrop along the Rio de Peixe. The occurrence f asphalt in the triassic eruptives of southern Brazil, however, has been known a long time, according to Dr. Gonzaga de Campos. It is generally believed that the Botacatú sandstone is always a hard vitrified rock, from the metamorphic action f. the overflowing eruptive contacts. In this region, however, the contact metamorphism is almost nil; the sandstone is slightly hardened in a narrow zone about 20 to 30 cm. wide. In many places, the sandstone is so friable as to be easily reduced to sand, which is used-.in, mortar for building in Guara-puava and Palmas. South and west from Porto União,. this bench of sandstone is about. 50 m. thick, and is capped by a heavy bed. f basic eruptives, many of which are amygdaloids. Dr. Geo: P. Merrill, after studying the triassic eruptives collected by the Coal Commission, reached the conclusion that. "All these rocks are of typical basalt-diabases, not in any essential different other than in structure. An interesting mineralogical phase is its paucity in olivine, which in many cases is completely lacking. Professor Hussak, who carefully studied these rocks and their accessory minerals, decided that in the dikes they are granular (diabase) and, that in the lava sheets, porphyritic (augite-porphyrite or melaphyre), and that the latter pass evidently to normal diabases and are always typical of effusive rocks. The examination f many slides from dikes and sheets leads us to adopt the opinion of Professor Hussak; the rocks of the dikes are of ophitic structure, while that of the sheets show a great variety f structure and may vary from almost granular to basaltic. The great paucity in olivine had been noted by Hussak, who classes as melaphyres, the porphyritic triassic rocks in Brazil which contain olivine.

Jan 4, 1921

By Peter O. Wilkinson

Ascot Racecourse in the UK is a major international venue for horseracing. The racecourse is being redeveloped to provide entirely new public facilities. The development includes the construction of a new grandstand. A site investigation was earned out comprising mainly cone penetration testing. The site is underlain by the Bagshot Formation, comprising predominately cohesionless deposits of medium dense becoming dense, silty fine to medium sand, containing occasional layers of clay. Shallow foundations would present uncertainty regarding total and differential movement; hence a piled foundation solution was chosen using a continuous flight auger (CFA) piling system. The possibility that piles may found either directly on or within the influence of cohesive material suggested uncertainty regarding toe resistance. In order to measure shaft friction, an instrumented preliminary test pile was undertaken. The results were compared to published correlations of cone and shaft resistance. This approach resulted in a net saving in terms of pile length which resulted in optimum value engineering and hence a cost saving to the client.

Jan 1, 2006