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By Midori Sakamoto, Nobuaki Sakuma, Tsuyoshi Murashita

Recently, tunnel blasting works near the residential area and existing building are increasing and environmental problems caused by vibration have become serious public concern. In order to solve these problems, blasting works have been conducted with segmented blasting and reduce advance per round. However, with these blasting, work efficiency is not obtained, and regrettably the cost and risk of accident tend to increase. We developed a new controlled tunnel blasting technique with electronic delay detonator. Electronic delay detonator can supply extremely large range of delay period which could not be achieved with conventional pyrotechnical delay detonators. We utilized advantages in initiating hole by hole over entire tunnel face at the same round. Much seismic data obtained from tunnel blasting with conventional detonator was statistically analyzed in order to find average duration time of vibration caused by a single hole initiation. Numerical simulation using sample waves from a single hole initiation was carried out in order to find an optimum delay time which can separate vibration in each hole initiation and without decreasing blast performance. Trial blasting was conducted to examine the correctness of optimum delay time obtained from numerical simulation. This blasting technique was applied to an actual tunnel construction. This tunnel is 2 lane automobile tunnel with a total length of 659 meters and internal cross section of 70 square meters. The purpose of the use of blasting technique on occasion, was the protection of fresh water reservoirs directly above the tunnel, and to keep the effect on local private houses to a minimum. The vibration level against this station was limited under 20 mm/see P.V.V. With this blasting, the tunnel construction was completed without exceeding the limited vibration level, with minimum cost and construction time.

Jan 1, 1998

There are no certain records available of coal shipments or production in Alabama before 1874, and the tonnages shown in Table 60 are estimated from dates of shipment, number of boats and similar data. They are not accurate but probably too low. There were no canals and all shipments were by river or rail, excepting the small tonnage hauled by wagons. [ ]

Jan 1, 1942

By Robert L. Bates

The field of industrial minerals and rocks includes such a wide diversity of materials and occurrences that communication is essential to foster a sense of "belonging? among geologists and other professionals. Besides, exchange of ideas and information is essential in meeting the needs of an ever-expanding world economy. A survey of the field shows to what an extent such communication--especially in the form of conferences and their proceedings--has increased during the past 25 years.

Jan 1, 1995

By F. Habashi

Japan was a closed society until 1853 when it was forced to open to the West. Mining, metallurgical, and geological education started there around 1861 when a graduate from Yale University in USA went to Japan to organize the first School of Mines. This was followed by other metallurgists from Great Britain, France, and Germany and thousands from other disciplines. The present report is a summary of the writer's first contact with Japanese metallurgists and his visits to a number of universities and research institutions in the past years.

Jan 1, 2012

HISTORIC SIGNIFICANCE OF EXPLOSIVES TO MINERAL PRODUCTION The ancient method of breaking rock was to build a wood fire against the face, heat the rock through and then pour water on the heated ore-bearing rock to cause it to break by tension. It was too slow and costly as the forests around the mines were cleared and transport of wood became difficult. Black powder had been used for 300 years as a gun propel- lant. ('Black' after Berthold Schwartz, a German monk, Figure 1, and the inventor of the gun who was given the epitaph `Here lies Berthold the Black, the most abominable of inhumans who by his invention has brought misery to the rest of humanity'). Only at the beginning of the 17th Century, black powder was introduced for loosening rock in European mines. In 1802 Dupont started black powder manufacture on the Brandywine Creek. The ignition train of powder was enclosed in goose quills, straws, rushes, paper or wooden tubes. The time interval between igni- tion and blast was pure speculation.

Jan 1, 1988

The nation of Fiji is located the South Pacific on the æRim of FireÆ some four hours flying time from the eastern sea board of Australia. It is a tourist destination situated on the main route from Australia to the Americas. Fiji is a developing country that has had a fewsetbacks but the country has able, happy people that are very resilient. Most importantly, the country is a safe destination for tourists and businesspeople as the local people are friendly, have good ethics, and most speak English. Fiji is a very willing nation, hungry for knowledge and advancement. The Fiji geological setting on the æRim of FireÆ, that runs from New Zealand across the Pacific through Fiji and on to Papua NewGuinea, has many large deposits of gold and copper. Fiji is an exciting destination for mineral explorers with discoveries of gold, silver, manganese, bauxite, iron and copper. Gold was first discovered in 1921 and the first two mines opened in 1935; one of which was Emperor Gold Mining Company (EGM) the other being Mt Kasi. EGM mines gold on the margin of the Tavua caldera, some 85 km north of the Nadi international airport. EGM has operated continuously for close to 70 years, producing approximately 6.9 million ounces of gold and has an underground reserve of 847 600 ounces with a total mineral resource of 12 335 600 tonnes at 10 g/t (as given in the Emperor Mines Limited Annual report 2003). The mineralisation in Fiji is very exciting and it is common to discover spectacular intersections and outcrops, which are typical for this type of epithermal narrow vein mineralisation, but be aware that the orebodies are variable and not easy to understand.

Jan 1, 2004

By Howard S. Strouth

SINCE the days of the Conquistadores, people have told exaggerated tales of the wealth and possibilities of Mexico and Central and South America, and the mining fraternity has never been known to exaggerate any less than any other professional group known to man or beast. However, during a short stay in Mexico one can probably hear more whoppers than at any other time, when dozens of mining propositions are thrust across the desk, and it is not necessary to remind anyone that a listing of the do's and don't's for Mexico requires special mention of the fact that most mining propositions offered south of the border eventually turn out to be a beautiful fairy tale. The following is not suposed to be either an exact description of Standard Mining Corp.'s operations in Mexico by its mining associate, the Corporacion Minera y Beneficiadora Anahuac, S.A., or the last word as to the most economical way to start such an operation. But rather it is the sum total of the recent experiences of the writer while commencing such an operation in 1951-52 with the help of many qualified gentlemen.

Jan 6, 1953

For many of us, formal academic education slows abruptly when we leave a tertiary institute of learning. We start applying and connecting newly acquired knowledge with the practicalities of a career, and begin to think in a manner that is technology-oriented. Subsequent vocational advancement is offered by the .many mining and professional journals that circulate through departments, and by conferences and schools that are organized in-house and via the SAIMM and other professional institutions. The importance of these schools cannot be overstated: they combine people and developing technology to the benefit of the industry as a whole.

Jan 1, 1992

of our good friends and fellow members: Patrick J. Quealy J. C. Roberts Gilbert Morton Sidney W. Farnham who left the world better for their having lived in it

Jan 1, 1930

All production data are shown in Table 64. [ ]

Jan 1, 1942

By R. G. Knickerbocker

A most important research and development item on ferroalloys in the calendar year of 1949 was the increase of interest in the recovery of secondary manganese. Owing to the importance of manganese to the nation's welfare, it is Ferroalloys most necessary that all possible avenues of research and development on the recovery of this vital metal be investigated. The principal objective of this new development is to recover manganese from steel furnace slags. Steel furnace slags contain a total of approximately 772,000 tons of metallic manganese which is compared to the 680,000 tons of metallic manganese as ferromanganese that is estimated to be used by the steel industry, annually, at this time.

Jan 6, 1950

By M. Brozek, W. Pawlos

"The separation of raw materials in the separator with ferromagnetic liquid occurs due to differences in magnetic and gravitational properties of respective components in relation to each other and to the liquid. In the separator with wedge-shaped pole shoes and the working space axis inclined at a certain angle to the horizontal direction, the paths of grain movement at fixed separation conditions depend on its physical properties. Due to this, the levels of grains outlet from the separator working space are differentiated according to differences in their physical properties. The distance between the levels of outlets from the separator working chamber depends on magnetization of the liquid which is proportional to the liquid density, on the magnetic field intensity and the inclination angle of the separator working passage to the horizontal axis. The separation accuracy is higher the larger is the distance between the outlet levels.The paper will present the methods of visual observation and recording of movement paths of coal grains of different physical properties in the paramagnetic liquid which was the water solution of manganese chloride. The paths were recorded with a video camera in the working chamber by means of a specially constructed device, acting as a periscope, which were then transformed into digital images. Experimental movement paths were confronted to the paths obtained in a theoretical way by means of solving differential equations of movement by a numerical method, achieving good compatibility of experimental and theoretical results. The equations of movement were solved with taking into consideration the drag force, expressed by formula for laminar and dynamic conditions of motion.The course of the path of grain movement depends on grain and liquid physical properties, magnetic field intensity and inclination angle of the working space to the horizontal direction. The two latter parameters can continuously control the process of separation."

Jan 1, 2003

The early gazetteers mentioned the mining of coal in this state but gave no output data Several of the bulletins of the Illinois Coal Mine Investigations give the results of some historical studies of parts of the state and some early production figures, but some make no mention of this phase of the industry Reports to the state by the various railroads of tonnages carried give figures for coal carried, but usually do not specify its origin These figures, however, when used for roads which crossed the various coal producing counties, and divided between counties in accordance with the little data available have furnished the base for the most of the estimates of county productions Some county histories furnished a few facts, and some were obtained from various other sources

Jan 1, 1942

PROGRESS IN DRILLING tungsten-carbide bits, lighter pneumatic drills, bonus plans, and alloy steels are discussed at northwestern gathering.

Jan 3, 1951

Some coal was mined in this area under lease from the Indians before it became a state. Table 75 shows all production figures available. [ ]

Jan 1, 1942

By John Petty, John Loviza

Single sentence describing content-- "The best ally an Explosives Engineer can have in a court of law is a regulations enforcer stating all codes and standards were met on a jobsite".

Jan 1, 1996

There are references to the early and continuous production of coal since 1851, but few definite figures. Some data were obtained from Bancroft, but nearly all the tonnages in Table 80, prior to 1869, are estimated. [ ]

Jan 1, 1942

By K. N. Han, M. C. Fuerstenau

Challenges in five major areas of hydrometallurgy are presented and discussed. These are: leaching low-grade oxide and sulfide ores; oxidative leaching of sulfide concentrates; processing refractory ores; bacterial leaching and processing: and secondary metal recovery.

Jan 1, 1989

Washington has been the largest coal producing state of the Pacific Coast, and the only one producing coke commercially. With the exception of the few estimated figures, the tonnages in Table 71 are from Goodyear and other sources as shown. [ ]

Jan 1, 1942

By B. J. Dalton

The Bureau of Mines Helium Activity has developed a computer program for use in the reduction of pressure-volume-temperature (PVT) data obtained with a Burnett compressibility apparatus. This program includes important modifications and extensions of some of the methods currently used for treating these types of data and yields statistical information that cannot be obtained from any other published work. The methods of calculation make use of a general nonlinear least-squares technique developed at the Helium Research Center. Because of a need to investigate different functional forms for representing the compressibility factor isotherm, 2, the computer program has been written in such a way that the only additional coding required is the so-called compressibility function subroutine. This subroutine defines the analytical form of Z and certain of its partial derivatives. The program described herein is believed to be the most advantageous for use in treating isothermal Burnett compressibility data.

Jan 1, 1970