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By Joseph M. Kuchta

This Bureau of Mines manual is oriented to the technical needs of an investigation of fire or explosion accidents and includes various practical and theoretical information that is needed in analyzing accidents or evaluating conditions that might lead to an accident. It is applicable to accidents in the chemical, mining, transportation, and other fuel-related industries. Specific procedures for conducting an accident investigation are outlined, and various guidelines are given for developing the fire or explosion evidence. Ignitability, flammability, and physicochemical data are presented for over 500 combustible gases, liquids, and solids; empirical and theoretical expressions are also given for extrapolating the behavior of combustible-oxidant-diluent systems to various environmental conditions. In addition, various data pertinent to damage analysis are summarized to facilitate the task of the investigator in developing plausible accident scenarios.

Jan 1, 1985

By Ian Thomson

The Social License to Operate ? We are operating in an era where social license in the resource industry is as important ? if not more important ? than mineral potential ? Concept proposed by Placer Dome executive Jim Cooney in 1997 as essential requirement for the future survival of the mining industry ? ?You don?t get your social license by going to a government ministry and making an application or simply paying a fee? It requires far more than money to truly become part of the communities in which you operate.? Pierre Lassonde, President of Newmont Mining Corporation (2003). What it is ?Granted by the local community ? Intangible, informal, non-permanent ? Has to be earned and then maintained ? Defined as ? Ongoing Acceptance (a lower level) ? Ongoing Approval (a higher level) ? Expression of the quality of the ?relationship?

Aug 1, 2013

By J. S. Rapp

This report is based on existing reports and recently gathered field data. It discusses mineral resource potential of Tertiary playas in the Fort Irwin region. An estimated 1.3 million tons of measured salt "reserves", and 20 million tons of indicated salt resources, have been identified north of the fort. Other indicated resources include 300,000 tons of celestite, 800,000 tons of gypsum, and 10 million tons of selenite. Zeolitic tuff was mined south of Fort Irwin from 1978 to 1984, and unexplored occurrences are widespread. Calcium-bentonite is mined near Barstow, and more may exist, including valuable sodium-and lithium-based bentonites.

Jan 1, 1992

By Joshua Hoffman, Braden Lusk, John Rathbun

A Flyrock Prevention Taskforce was established in Kentucky with the support of Kentucky's Department of Natural Resources, Kentucky's Explosives Industry, and the University of Kentucky. This paper presents the initial work of the Flyrock Prevention Taskforce towards its missions of identifying the root causes of flyrock incidents based on the analysis of previous events, and tracking the progress of flyrock elimination in the future. Work identifying root causes of flyrock events is presented through the development of a database which manages information about the blasts which caused flyrock. This data includes: blasting and seismograph records, drill logs, videos of the event when available, company notes/incident reports, and any additional information regarding probable cause. Work tracking the progression of flyrock elimination efforts is presented in this paper through the introduction of a flyrock index. Several metrics are proposed for this index, and are discussed for their appropriateness and shortcomings. In order for these indexes to be valid forms of tracking flyrock incident rates additional records must be kept and reported, such as the annual consumption of explosives by surface coal blasting. Suggestions for record keeping, flyrock investigation practices, and means of tracking flyrock incident rates are proposed in this paper.

Jan 1, 2013

By F. E. Walker, S. J. Aresco, J. B. Janus

The Bureau of Mines has been active in promoting the purchase of coal for Government use under specifications that define the requirements in terms of heating value of the coal , expressed in British thermal units , and the composition as shown by proximate analyses . To these , when required , are added the ash- softening temperature , the free - swelling index , and the Hardgrove grindability index . Under most of these specification contracts the bidders guarantee the quality of the coal , and that guaranteed by the successful bidder becomes the standard of his contract . The deliveries are sampled in accordance with instructions 4/ issued by the Bureau of Mines ; the samples are analyzed in the Bureau laboratory to determine whether the coal is of the quality guaranteed by the contractor and , if it is not , a price adjustment is made . Analyses of the delivered coal and tipple samples ( samples collected at mine tipples as coal is being loaded into railroad cars or trucks ) provide valuable data for use in evaluating future bids . In addition , the continuous sampling of coal as delivered is a check on the practical results obtained in burning the coal . The Government purchased approximately 5 million tons of coal in fiscal year 1962. In connection with these purchases , the Bureau analyzed 7,114 samples . These are published ( table 1 ) for the use of Government officials and the public . A series of publications has been completed on coal analyses by States or , where production is small in any one State , by groups of adjacent States . In addition to analytical data showing composition and quality of coals of the States , the publications contain brief descriptions

Jan 1, 1963

By Fábio de Oliveira Braga

Atualmente, tecidos de fibras sintéticas como a aramida (Kevlar®) e o polietileno (Dyneema®) têm sido os preferidos para proteção balística contra munições leves, e para integrar sistemas de proteção contra calibres superiores, como o 7,62 mm. Porém, por apelos econômicos, ambientais e da disponibilidade limitada destes produtos, materiais alternativos têm sido testados. Neste cenário, destacam-se os compósitos reforçados com fibras naturais, que têm demonstrado bom desempenho balístico. Assim, o objetivo deste trabalho é avaliar o desempenho individual de compósitos reforçados com fibras naturais de curauá, quando submetidos ao impacto balístico com munição 7,62 mm. Foram executados ensaios balísticos, medindo-se a energia do projétil absorvida pelos materais, e os resultados tratados estatisticamente por Anova e teste de Tukey. Mostrou-se que estes compósitos têm potencial para substituir as fibras sintéticas em sistemas de blindagem para proteção pessoal, com a vantagem de serem materiais leves, de baixo custo, nacionais, de ampla disponibilidade e ambientalmente corretos.

Aug 17, 2017

By A. M. Poston

Introduction of radioactive elements into ore samples and/or pregnant liquors and radiometric tracing thereof have greatly improved control of fusion and extraction studies on beryllium ores and products. Extractive metallurgical research on beryllium, normally guided by the usual laborious analytical methods, is both costly and slow. Recognition of this problem by the Bureau of Mines led to the development and application of radioisotope tracer techniques" as a substitute for chemical analysis at the Salt Lake City Metallurgy Research Center, The result was that much faster progress at significantly lower cost was achieved. This report discusses the problems encountered and resolved in using radioactive tracers and radiometric methods, defines the conditions and techniques for their effective use, and delineates the limitations and flexibility inherent in applying such methods in laboratory-scale beryllium research.

Jan 1, 1962

Real Time and In Situ Measurement of Elemental Composition Using Lasers

Sep 13, 2010

By H. A. Domian, H. Biloni, G. F. Bolling

Jan 1, 1965

Economically significant gold-silver mineralization occurs in Miocene andesitic flows and tuffs at Golden Cross, eight kilometres northwest of Waihi, New Zealand. The highest grade mineralization occurs in a steeply dipping elongate zone of strong quartz veining and brecciation underlying, but contiguous with, a gently dipping tabular quartz vein stockwork containing potentially open-pittable lower grade gold-silver mineralisation. The stockwork zone is enveloped by argillic alteration and overlain by unaltered Pliocene andesites and recent tephra. Evaluation of the prospect involved underground and surface geologic mapping, rock and soil geochemistry, IP-resistivity, magnetic and gravity surveys as well as 1844 metres of reverse circulation drilling and over 30 000 metres of core drilling. The paper outlines the exploration history of the area and describes the results of the various exploration techniques used at Golden Cross.

Jan 1, 1986

By Asmo Vartiainen

Background of Direct-to-Blister Flash Smelting is discussed; especially slag chemistry relating to copper solubility, slag fluidity and impurity behavior. In December, 2000, Mini-pilot Flash Smelting test runs were carried out at Outokumpu Research Oy to produce blister copper from Chilean concentrate and white metal and from a mixture of them. Tested slag types were iron silicate slag, ferrous calcium silicate slag and calcium ferrite slag with different slag compositions and different concentrate/white metal ratios. The test runs were successful. The fluxing effect of copper oxide was clearly demonstrated and ferrous calcium silicate slags remained fluid on a very wide liquidus range. The distribution of arsenic between ferrous calcium silicate slag and blister copper is much higher than between iron silicate slag and blister copper. This successful test run with the new slag type offer new possibilities in Direct- to-Blister process design.

Jan 1, 2003

By Jackson R. Pressley, M L. Hopkins, R E. Danell, N T. Moxon, Andrew Bowman

Efficient and cost effective blasting is achieved by closely matching the explosive energy to the strength of the material in which it is being used. Although there are many empirical relationships wich approximate this situation complete the blast optimization can only be achieved by quantitatively assessing explosive/rock interactions and explosive performance. The performance of an explosive is essentially governed by its velocity of detonation or the rate at which the detonation wave travels through the explosive column.

Jan 1, 1991

By R. D. Brown

On November 16, 1978, Finance Minister Chretien delivered his second formal budget in the House of Commons. Over-all, the provisions of the budget should provide moderate stimulus to the Canadian economy. With respect to the mining industry, the budget offers some welcome changes in the form of' improved write-offs for development expenses and social assets; higher investment tax credits; and a reduction in federal sales tax. On the other hand, income bond financing of new mineral ventures may be restricted.

Jan 1, 1979

By Harold J. Miller

Loading and haulage of run-of-mine ore is frequently the highest cost in underground mining operations. These costs can be significantly reduced by use of belt conveyors, a common practice in coal and similar soft miner ii mines. This is particularly true if oversize ore and rock can he eliminated prior to conveying; thus producing a demand for crushers near the production areas. Portable feeder-breakers are extensively used in conveyorized mines, but no suitable, equivalent equipment, is available to provide these benefits to hard rock mines of low to medium headroom. A hard rock crusher capable of easy movement and readily disassembled would allow use to belt conveyors and could improve the general safety and productivity of any underground ore hauling system. This report summarizes proposals and findings made in conjunction with the newly designed M-44 Low Head Portable Crusher which is believed well capable of meeting the requirements of a "portable, underground, hard rock" machine as previously defined in earlier reports. Data gathered by use of the 1/4 Scale Model of the M-44 has substantiated and verified the concept sufficiently to justify construction of a full-size machine for further testing under actual mine conditions.

Jan 1, 1978

By S. N. Lekakh

Phosphorous segregated at grain boundaries during solidification and heat treatment dramatically decreases low temperature toughness of precipitation hardened Fe-Mn-Al-C austenitic steel. A thermodynamic analysis was performed to evaluate the possibility of decreasing P and subsequent segregation by Ca- and Ce-additives in the melt. It was shown that the predicted probability of forming a P containing compounds depends on melt composition and treatment sequence. Experimental heats were performed and several micro- and macro-structural effects of Ca- and Ce-additives were recognized by using an automated inclusion analysis technique.

Jan 1, 2010

By C E. J de Ronde, J L. Mauk

Sulfide chimney samples collected during the 1998 - 1999 R/V Atlantis û DSV Alvin 3 - 30 research cruise have been examined and classified into four types, based on common characteristics. Chimney morphology is the most important characteristic and resulted in the following groups: 1. flutes, 2. cones, 3. wide-flats, and 4. beehives. Other characteristics resulted in the classification of subgroups within the flute, cone and wide-flat groups. The combination of characteristics, including; the presence of an orifice, internal chimney fabrics, wall thickness, extent of weathering, and the presence of Alvinella worm casts, enable evolutionary trends between the different chimneys types to be established. These trends indicate that with time, flutes evolve from immature zoned chimneys with a central orifice and smooth thin-walls, into cone chimneys with thick walls and massive fabrics which have their orifices infilled by massive sulfides, and a rough exterior. Repeated mineralisation within, cones may result in the formation of wide-flat chimneys. Beehive chimneys can form at any time during chimney growth.

Jan 1, 2003

By J. D. Vincent

The Henderson mine site is located at Red Mountain on the eastern slope of the Rocky Mountains, approximately 50 miles west of Denver, Colorado. The mill site is on the west slope of the Rockies and mine and mill will be connected by an underground railroad. All designs were for a 30,000 ton per day molybdenite processing plant with provisions for future expansion up to 50,000 ton per day if required. This plan did not just happen, but slowly evolved over the course of about three and one-half years. Many plants cannot afford such a delay, but the Henderson project will take about 10 years from the time it was first discovered until production starts, and these 3 !1 years were well spent in determining the best possible plant site and flowsheet. This paper describes some of the problems and the decisions made in arriving at the final location and flowsheet. The paper does not go into the specific details of how protection of the environment went hand-in-hand with all other project considerations. This particular aspect of the planning has been well-reported on other occasions and considerable information on it is readily available.

Jan 1, 1972

By Donald Crowell

Due to falling metal prices and depletion of ore reserves, lead-zinc mining in the Leadville, Colorado, area gradually came to a halt in the 1950's. Exploration work continued, however, and by 1969 sufficient ore had been blocked out to warrant sinking a shaft and erecting a new concentrator to treat 700 tpd. The new shaft and concentrator were to be located in Iowa Gulch several miles east of Leadville at an elevation of 11,100 ft. The Leadville project is a joint venture between Newmont Mining Company and ASARCO with ASARCO being the operator. Design work began in the fall of 1969. Engineering was done by Torkelson Engineering Company of Salt Lake City in conjunction with the Central Engineering Department of ASARCO. The plant was constructed by Stearns-Roger Corporation. Construction began in the spring of 1970 and the plant went onstream in April, 1971. Flow sheets and equipment lists are attached. This paper will describe the flow sheet very briefly and discuss in more detail those aspects of the design which may be of interest, particularly the provisions for expanding the capacity of the plant.

Jan 1, 1972

By Gloyd M. Wiles

The property of the Park City Consolidated Mines Co. is situated in the northeast part of the Park City dining district 1 mile east of the town of Park City. The elevation at the collar of No. 1 shaft is 7,250 feet. Park City is a town of approximately 4,500 population lying about 30 miles east of Salt Lake City. The two are connected by an oiled State Highway, which is cleared of snow in winter and maintained in first-class con¬dition by the State throughout the year. The district is served by branches of the Denver & Rio Grande Western and Union Pacific Railroads, each operating on a daily' schedule, except Sunday. These two railroads have constructed 1 ½ miles of joint track from the town to the Park City Consolidated Mines Co. loading tipple, located 200 feet from the portal of the adit that leads to No. 1 shaft.

Jan 1, 1936

By S. Mao

Total station has been predominantly applied in stationary survey scenarios in construction. With the moving target tracking and point survey automation functions, a robotic total station (RTS) lends itself well to more dynamic applications. Nevertheless, a RTS unit is still unable to track multiple targets simultaneously or to survey a target point when the line-of-sight is temporarily unavailable. In this paper, we propose a methodology to synchronize and automate multiple RTS units intended to address dynamic tracking and surveying applications in the construction field. By using the application programming interface (API) from the manufacturer, we implement the proposed methodology and the prototype system integrates two RTS units in regard to space and time and communicates survey command instructions among RTS units through wireless networks. The two RTS units can be operated to survey the two ends of one swinging sling concurrently in order to retrieve the actual length of the sling within several millimeters accuracy. Besides, in applications where line-of-sight between a target object and one RTS unit cannot be guaranteed all the time, continuous surveying can be materialized by automatically delegating the task to another synchronized RTS unit with clear view of the target object. A field test was conducted to demonstrate the application of the proposed automation approach in which sling length was measured of a rigging framework used for lifting industrial modules. The testing results are presented and achievable accuracy and reliability are discussed. The proposed solution overcomes the limitations of global positioning system (GPS) and laser scanning and holds high potential to provide cost effective solutions to many dynamic field applications.

Aug 1, 2013