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By Carl D. Ealy

Work is being done to web enable the FHWA Deep foundation Load Test Database. Originally designed to function in the client server environment via modem, access to the database both for data maintenance and user queries has been upgraded to take advantage of the Internet and current and future information technology innovations. The DFLTD will be part of an Automated Geotechnical Information and Design Aid System, the object of which is to assist those involved with managing and maintaining our nation's highway infrastructure. The system will also meet the needs of university and other research institutions for a statistically meaningful source of high quality data for the development and verification of improved analysis methods, in-situ testing methods, etc.

Jan 1, 2002

By T. M. Barczak, S. C. Tadolini

Reduction in the recovery time required and improvements in safety during a longwall face move have compelled coal mine operators to examine and use pre-driven longwall recovery rooms. The recovery entry is developed at the longwall stop position and supported ahead of time so that the required combinations of standing and internal supports can be installed before the longwall face approaches. A calibrated three-dimensional finite element model, developed in conjunction with an underground test area, provided the critical components and design principals for a comprehensive parametric study. The study indicates that vertical, horizontal, and shear stresses concentrated on the outby abutment pillar corner of the recovery room resulting in deformations in the immediate roof above the primary roof support anchorage level. The results of the numerical model and field site observations indicated that the combination of the internal bolting system and the standing concrete supports are critical for the successful and safe extraction of the longwall equipment. Cable supports installed at and angle over the pillars can help stabilize the disturbed zone above the adjacent fender and outby pillars, however; standing supports are required in most sedimentary roof conditions to increase stability and assure a safe longwall extraction.

By B. Spigarelli

Carbon dioxide sequestration by conversion to carbonates has become a promising option for CO2 storage. Experiments were conducted to determine the feasibility of CO2 sequestration at ambient conditions using a Ca-rich industrial waste in a carbonate solution. The Ca-rich industrial waste used in this study was lignite fly ash. Fly ash was chosen because it is cheap, available near large CO2 point sources, already in powder form, and reactive due to amorphous properties. In the experimental set-up, CO2 absorption was inferred by monitoring feed and exhaust gas CO2 concentrations. The addition of an alkali to a fly ash-distilled water solution provided a 50% increase in CO2 absorption of the solution. Absorption time also increased by 50% compared to a fly ash-distilled water solution. TGA analysis was used to determine the extent of CO2 sequestration in the carbonate form. At a liquid to solid ratio of 20:1, the conversion of ?free? calcium to carbonates was 75%. A CO2 balance on the system concluded that at the current operating conditions 42% of the total CO2 fed to the system was sequestered in the carbonate form. SEM-EDS analysis of the fly ash particles before and after reaction with CO2 indicated that the carbonate compound being formed was calcium carbonate. The analysis identified rhomboidal structures on the surface of the fly ash particles after reaction with CO2, but not before. These rhomboids are characteristic of calcium carbonate formation and they had higher Ca, C, and O concentrations than the host spheres, suggesting calcium carbonate formation.

Jan 1, 2012

By G J. Corbett, T M. Leach

Although hosted within an Ordovician magmatic arc, the Peak Hill high sulphidation system displays features typical of youngerPacific Rim high sulphidation epithermal gold deposits. Regional NW trending transfer structures are inferred to localise the magmatic source at their intersection of the NS trending arc. Fluids have migrated from the magmatic source along NW structures and thence exploited permeable horizons, which have become silicified. Alteration displays typical zonation from silicification through assemblages characterised by alunite, pyrophyllite and kaolinite and is followed by breccia/fracture controlled sulphide and gold deposition. Sinistral rotation on the NS arc has dilated NW trending fractures to produce the WNW to EW dilational fractures which host the higher grade ore. Mineral assemblages are typical of formation distal to the magmatic source in an epithermal environment. The combination of alteration and mineralisation zonation with structure provide fluid vectors which target a magmatic source to the SE of Peak Hill.

Jan 1, 1995

By Hongfei Li, JianLong Wang

This paper introduces the technical characteristics, transformation scheme and production practice of the project in which Copper P-S Converter was replaced by Bottom Blowing Continuous converting for the first time, and introduces the technical achievements obtained by the project. The application practice proves that bottom blowing copper continuous converting technology can completely solve the problems of fugitive off-gas pollution in the ladle transportation, large amount of flue gas and fluctuation of flue gas caused by P-S converting. Comprehensive energy consumption and operating costs of producing blister copper, safety and environmental risks are greatly reduced, and economic, environmental and social benefits are significant. It is one of the preferred technologies for upgrade and to replace P-S converting technology. INTRODUCTION At present, more than 80% of copper production capacity is still using the P-S converting technology with a history of more than 100 years. During P-S converting process, melted copper matte needs to be transported by ladle, and it needs to rotate the furnace body several times, causing a lot of serious environmental and safety risks such as SO2 flue gas emission and low-altitude SO2 pollution. In addition, the high operating cost caused by low rate of air blowing, the short life of the refractory materials and high energy consumption during P-S converting become big problems. Other problems such as large amount of flue gas, low SO2 concentration, large fluctuation of flue gas volume and SO2 concentration, and discontinuous flue gas cause high cost of subsequent flue gas treatment are also needing to be solved. In order to solve these problems during the P-S converting, metallurgical engineer in various countries has spared a lot of efforts to develop continuous blowing process for decades. The continuous converting that have been industrially applied are flash continuous converting, Mitsubishi continuous converting, Noranda continuous converting, Bottom Blowing Continuous converting and multi-lance top blowing continuous converting

Jan 1, 2019

By Parviz F. Rad

The Bureau of Mines used a linear cutting apparatus equipped with a 7-inch disk cutter to cut grooves in marble, limestone, granite, and quartzite under a normal force of 7,000 lb. The size distribution of the muck for various grooves was determined through sieve analysis. A statistical search showed that Weibull distribution describes the size distribution better than other available functions. Results indicate that fineness modulus, chip population, and dimension of the largest chip can be used as indicators of cutting efficiency. The results correlate with those obtained from the boring machines and other lab experiments. Application of the principles established through this work to the operation of boring machines is explained

Jan 1, 1974

By D. J. Greeff

By making use of genetic programming, empirical models for metallurgical processes can be evolved that are more cost-effective than models determined by means of classical statistical techniques. These methods explore populations of candidate models assembled from sets of variables, parameters and simple mathematical operators, and do not require explicit specification of model structures. The application of the proposed strategies is illustrated by means of a case study pertaining to the leaching of nickeliferous chromite ores. Modelling of the nickel and cobalt extraction from the ores yielded models of similar accuracy compared to those obtained by non-linear regression and artificial neural networks. However, in the case of the iron extraction from the ores, the genetic programming model was significantly more accurate than both the regression and neutral network models.

Jan 1, 1998

By Leopoldo Mariscal

El presente trabajo describe los aspectos más importantes del proyecto de Fundición de Ilo como son: la tecnología, el desarrollo de la ingeniería y construcción, el impacto económico, social, tecnológico y ambiental de su ejecución y los planes de entrenamiento y comisionado de la nueva planta. Asimismo considera entre los equipos principales: un horno de fusión en baño ISASMELT asociado a un caldero de recuperación de calor y un precipitador electroestático, cuatro convertidores Peirce Smith, dos electroprecipitadores, dos plantas de ácido, dos plantas de oxigeno, dos plantas de efluentes, una planta de moldeo de ánodos, dos hornos de limpieza de escoria, y varias plantas auxiliares más.

Sep 12, 2005

By Donald A. Bruce

"Abstract The Deep Mixing Methods (DMM), in their current forms, have been employed in the United States since 1986, although an earlier version had seen service from 1954. The earlier developments were strongly influenced by practices in the Nordic countries and Japan, while by the late 1980’s several DMM systems had been developed in the U.S. itself. Since then, DMM has continued its evolution, principally via the challenges of a series of large, landmark projects, but also via distinct, significant technological advances. This paper highlights the key points in the history of DMM in the U.S., and provides an overview of the different methods currently in use.In the BeginningIt is a common misconception that the history of applications of the Deep Mixing Methods (DMM) in the United States dates from 1986 when SMW Seiko Inc. — a subsidiary of Japan’s Seiko Kogyo Company — was established in the Bay Area. However, the author believes that Intrusion Prepakt Co.’s patented MIP (Mixed in Place) system had been used, albeit sporadically (about 30 projects are recorded), since 1954 (FHWA 2000, 2001). Ironically, by 1961 this single auger method had been extensively used under license in Japan for excavation support and groundwater control — by the Seiko Kogyo Company. By 1972, the original MIP technique had been succeeded by more advanced Japanese methods, involving multiple augers. Intrusion Prepakt have long since become defunct.The first systematic studies of contemporary Deep Mixing Methods in Japan began in 1967 when the Port and Harbor Research Institute of the Ministry of Transportation began laboratory testing using granular and powdered lime for treating soft marine soils. Fundamental studies continued through the early 1970’s, by which time the development of industrial scale equipment was well advanced, having its first application on a marine trial near Haneda Airport. Coincidentally, laboratory and field research also began in 1967 in Sweden (“Swedish Lime Column Method”) for treating soft clays using unslaked lime. Reportedly the progenitor was a Norwegian, Kjeld Paus, who had made observations on fluid lime columns in the U.S. It would seem that developments in Japan and the Nordic countries proceeded independently until 1975 when the technology leaders from each group (Broms and Boman; and Okumura and Terashi, respectively) presented their — very similar — findings at a conference in Bangalore, India. Limited technical exchanges ensued thereafter.Whereas the Nordic developments continued to focus on the use of dry reagents (cement and lime) and relatively light equipment compatible with operating on and in very soft clays and organics, the Japanese progressed into the use of fluid reagents (cement-based grouts) and heavier equipment for both marine and land-based projects. Thus, by 1986, there were a large number of proprietary (wet and dry) DMM systems in Japan, and a rapidly growing market already by then accounting for over 12,000,000 m3 of ground treatment."

Jan 1, 2014

By Roberto Folchi

This note deals about the controlled demolition work for the dismantling of an industrial structure in San Seplocro, Italy. The structure to be demolished, the FLOWERS SILOS, consisted in a multilevel reinforced concrete frame supporting r.c. silos and steel silos. This was standing near civil buildings and was adjoining a warehouse that had to be safeguarded for being renewed.

Jan 1, 1994

By L. W. Higley

Electrowinning metals from solutions leached from low-grade ores is becoming an increasingly important extraction method as the metal industry turns to pollution-free recovery processes. Lead-alloy anodes are used industrially in the electrolytic recovery of zinc and copper. However, associated with the use of these anodes are the inherent problems of stability and lead contamination of the cathode. In an effort to eliminate these problems, the Bureau of Mines has developed a relatively inexpensive lead dioxide anode for electrowinning metals from strong acid solutions. The anode was prepared by depositing Pb02 directly on a titanium blank in a strong HN03-Pb(N03)2 solution at 2.15 to 6.45 A/dm2 and 60° C. This anode was tested in zinc and copper electrowinning cells containing 200 gpl H2S04 and 35 to 100 gpl metal ions at the current density of 3.23 to 6.45 A/dm2. Contamination of the cathode by lead was =0.005 pet. A 30-day test at 6.45 to 12.90 A/dm2 in an electrolyte containing 200 gpl H2S04 and no metal ions resulted in a slight change in surface morphology of the Pb02 anode but no measurable change in anode weight or dimensions.

Jan 1, 1976

By D. E. Sherwood

Recent developments in high torque hydraulic rotary rigs has lead to the construction of secant bored pile walls by rotary drilling methods in circumstances where earlier methods were difficult and in some cases impossible. The evolution of secant bored pile wall construction is described including classical, rotary drilled and continuous flight auger construction methods. The paper then details the restraints which have been created in recent inner city redevelopment, many of which were not relevant in the early days of the technique. Typical examples of walls are presented to show the adapatability and advantages of the secant bored pile wall method. A number of in-situ retaining wall construction techniques are then compared in detail with regard to relative cost, technical quality and practicality.

Jan 1, 1989

By Xu H.

In recent years, the mineral applications dealing with more complex data in distributed environment have grown rapidly. Many mineral and mining organizations have to organize internally and globally distributed manufacturing and experiment sites, which share the roles of databases and other multi-services like software programs. Thus, there are commercial and technical pressures pushing the mineral software vendors to move their current service toward Web service. XML has gained wide acceptance for representing, storing and transferring structured data and documents of many kinds, especially in scientific communities. However, so far there is no such a Markup Language in mineral industry. A XML-based uniform encoding, which is called MineML(Mineral Markup Language), is proposed and developed in this project. The framework of the MineML specification is created. MineML will play the role as shared protocols within mineral domain for archiving, transferring the multi-nature data between the software packages on the desktop over the Internet and sharing the services between users at different sites. Inspired by MLA’s (Mineral Liberation Analyser, JKMRC, University of Queensland, Australia) Mineralogical Data Presentation Program, a proof-of-concept prototype of Web Service is developed here to validate and demonstrate the MineML specification. Certain strategies, specific technologies and tools are adopted to create such an environment. To accomplish that, a set of experimental MineML documents including correlated XML, XSD (schemas) and XSL(stylesheets) documents have been elaborated for archiving, presenting and transferring the mineralogical data information, with the persistence on flexibility and extensibility for generic mineral and mining data handling.

Jan 1, 2003

By Bryan A. Bartley

"Jim Macdonald was promoted from Waterworks Engineer to Streetworks Engineer for the Wellington City Council. He thus took over the City quarry and responsibility for its performance. The crushing plant needed upgrading and he thought it would not be difficult to make a crusher to overcome a problem. If he had a longer association with the quarry industry he would have used conventional methods and equipment, so his invention arose from a fresh view of crushing.He invented the Barmac Rotopactor after observing a wear resistant chute with a lining of dead stone trapped above a piece of angle. This idea led to a rotor lined with trapped stone, rotating on a vertical spindle. In trying - a model rotor he observed the impact against a circular rill of stone in half an oil drum and thus was started a very fertile new area of developement in comminution. The writer helped in the developement and shares in the patents. Jim died in January 1982, just as the machine was becoming known and some 200 were in use in various countries. Most were working in hard rock quarries et that time but recent uses have carried the machine into the mining and mineral processing field. This paper is directed at that industry."

Jan 1, 1985

By Nicol S. K, Firth B. A

Much effort over the years has been put into the task of devising parameters which adequately assess the metallurgical efficiency of mineral processmg operations. One of the most celebrated of these methods is the so-called "release analysis" method of Dell (1953) which tackles the problem in terms of an ideal separation based on sequential retreatment of the products and tails of a given separation process. Other methods have also been proposed by Jowett (1969) and by Holland-Batt (1971 ). While these procedures are appropriate to multi-component mineralogical separations, they perhaps do not lend themselves to the much more simple two-component systems encountered in coal preparation. However Dell (1962) has suggested the use of the term "specific profit" in coal preparation in order to assess the conditions that give maximum economic gain. Specific profit is derived from data relating washability data with equipment performance and operating costs. The procedure for using this criterion for comparative purposes is therefore somewhat cumbersome as is illustrated by its lack of widespread acceptance in the coal preparation literature.In contrast, an efficiency index, E, which is both simple and meaningful from the utilitarian standpoint, has been proposed by Tsiperovich and Evtushenko (1959a). This index is defined by the relation, E = Yield X Tailings ash/Product ash (1) A cursory examination of this parameter shows that it increases when yield and tailings ash increase and also when product ash decreases; all of which are desirable circumstances in coal cleaning operations.Further, it will be shown that slight variations in operation are amplified by this function which makes comparisons simple and direct.While the use of this index is quite extensive in the Soviet coal preparation literature for some reason it has not received wide usag~ elsewhere.

Jan 1, 1978

By Keith Mayhew

Ante la alta demanda de cobre por el crecimiento urbano e industrial y para la construcción de infraestructuras, la industria del cobre necesita una solución para el desarrollo sustentable de los recursos minerales de cobre con alto contenido de arsénico. En ese sentido, Teck Resources Limited (Teck) y Aurubis AG (Aurubis) están trabajando juntas para desarrollar una tecnología que sea aceptable desde los puntos de vista regulatorio, medioambiental, social y económico. Por ello, el presente trabajo señala los resultados obtenidos por Teck-Aurubis conjuntamente, como consecuencia del programa técnico desarrollado desde 2010 para el tratamiento con éxito de concentrados de cobre con alto contenido de enargita usando la tecnología CESL.

Sep 12, 2011

By John Kosek

The electrochemistry of carbon monoxide, nitric oxide and nitrogen dioxide was investigated at a variety of electrode materials in different supporting electrolytes. A portable detector for carbon monoxide was developed using a porous gold anode in perchloric acid supporting electrolyte. This detector has two full scale ranges, 0-100 ppm and 0-500 ppm. A portable detector for mixtures of nitric oxide and nitrogen dioxide was developed using a porous silver cathode in sulfuric acid supporting electrolyte. Nitrogen dioxide was determined in the gas stream by electroreduction. The nitric oxide in the gas stream was oxidized to nitrogen dioxide by passing it over Cr(VI) on firebrick. Electroreduction gave the sum of NO + N02. Analog circuitry was used to display the amounts of NO and N02 separately. Two ranges were available for each gas. They were 0-10 and 0-50 ppm for NO and 0-2 and 0-10 ppm for N02.

Jan 1, 1979

By J. T. Popp

This Bureau of Mines study reviews the geological factors that affect methane in the Beckley coalbed in southern West Virginia, including overburden, coalbed structure, type of and changes in lithology above and below the Beckley coalbed, and presence of fractures in the coal and rock adjacent to the Beckley. Depending on the depth, the Beckley coalbed emits from 216 to 520 ft3 of methane per ton of coal mined, and the Bureau estimates that methane emission in a deep, extensively developed mine in this area may exceed 3,000 ft3 per day per ton of coal mined. Average face cleat and butt cleat trends in the Beckley coalbed measured underground are N 33° W and N 53° E, respectively. Close cleat spacing con¬tributes to the friable nature of the Beckley and provides easy movement for methane and water. Because rider coals, splits, and carbonaceous shales may contribute methane to mine emissions, predictions of methane emission based on gas content of the Beckley coalbed alone may be conservative. Beckley coalbed reserves in the study area are 234 million tons. The gas content of the Beckley coalbed averages 407 ft3/ton, and the coalbed gas reserves are 108 billion ft3.

Jan 1, 1976

By Kenneth H. Johnston

This publication describes a thermal-recovery project and two waterflood projects in Carter, Garvin, and Stephens Counties, Okla., that will be visited during the 1966 annual tour by the Bureau of Mines in cooperation with the Kansas-Oklahoma Waterflood Association. Among the unique features of the projects arc (1) the movement of heavy (15° to 28° API gravity) crude oil through the reservoir and into the well bore with energy furnished by burning a portion of the crude oil therein; (2) the use of an inverted nine-spot pattern with dually completed injection wells, to produce oil from deep (8,200 to 10,200 feet) reservoirs; and (3) the flooding of five sand lenses separately by using controlled water injections through multizone completed injection wells. Discussion of the individual projects includes information on their early history, method of completing and operating wells, source and treatment of injection fluids, oil production decline curves, and the results obtained from the development.

Jan 1, 1966

By Jean-François Dorion

La corrosivité des environnements miniers souterrains est un phénomène peu étudié au Canada. En plus de détériorer les systèmes de soutènement, la corrosion s?attaque aussi à divers installations et équipements souterrains. Cette étude, débutée en janvier 2007, est l?établissement d?une banque de données afin de caractériser les environnements miniers souterrains selon leur potentiel de corrosivité pour les systèmes de support de terrains. Pour ce faire, cinq (5) mines ont été sélectionnées afin de comparer les environnements : Laronde, Géant-Dormant, Niobec, Mouska et Doyon. À chacune des mines, trois (3) endroits ont été étudiés. Les résultats préliminaires démontrent une grande variabilité des conditions d?une mine à l?autre ainsi qu?à l?intérieur même d?une mine. La minéralogie des roches et du gisement influence la composition des eaux souterraines et la présence des sulfures joue un rôle important sur l?agressivité de l?eau et de l?air des mines de l?étude. Afin de déterminer le potentiel de corrosivité, plusieurs paramètres doivent être considérés et la mine doit être zonée selon l?agressivité des endroits.

Feb 1, 2008