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By Michael G. Zabetakis

The spillage of liquid diethyl ether in rooms at floor level and 3 feet above the floor resulted in flammable vapor-air mixtures in the immediate vicinity of the exposed liquido The liquid temperature was found to decrease by as much as 35° C., with a resultant decrease in vaporization rate. A search of the literature yielded numerous references to unstable peroxide (residue) formed by the autoxidation of ether. Such residues appear to constitute an explosion hazard in the condensed state.

Jan 1, 1962

By J. A. López-Molina, S. García, V. Castellanos-Pedroza

"Groundwater inflow into underground constructions may cause hazardous working conditions and environmental problems. It is essential to localize and characterize potential flow paths and to estimate the amount of water leakages, so that appropriate sealing works can be performed. Estimating the amount of water ingress is a multi-phase process starting from qualitative and quantitative examination of rock mass. Due to association of uncertainty, vagueness and incompleteness with the monitored data set, particularly resulted from the in situ tests, accounting relevant approaches such Fuzzy Logic and Recurrent Neural Networks, are proposed in this research for learning acquisition, extraction of rules and prediction of behaviors. The computational set of artificial tools permits using the complex information entities or information granules (rock types, geologic structures, hydro-fracture potential) for data abstraction and derivation of knowledge from records (numerical or linguistic format). This is more a theoretical perspective than a set of methods or principles. As a theoretical perspective, this proposal encourages an approach to data that recognizes and exploits the information present in indexes at various levels of resolution or scales. In this sense, it encompasses the methods which provide flexibility and adaptability in the resolution at which knowledge or information is extracted and represented. The product of merging these tools is a 3D artificial-mapping of rock classification (Qi-system), geological conditions and Lugeon units that permits, as far as possible, to understand more and better the flow behavior."

Jan 1, 2015

By J. R. Thoenen

In the summer of 1937 the authors began a series of time studies of the various processes employed in the production of crushed stone. These studies, made at quarries scattered over the eastern and southeastern parts of the United States, have not been completed, but to make results available to thee industry as early as possible it was decided to publish summaries of the studies made to January 1, 1939, as a series of progress reports. The first of these reports dealt with power-shovel loading and was issued as Report of Investigations 3461 in September 1939. The present circular discusses analyses of the time Studies of the haulage systems at the same quarries. OBJECT OF STUDY The pressure of business problems frequently requires the entire attention of quarry management and in consequence internal plant economies often are neglected, Also, operating officials absorbed in their local problems are prone to overlook possible economies that would attract attention immediately were they critically examining another plant. The authors felt that similar studies of many plants by impartial engineers -would disclose possibilities for cost reduction or greater efficiency in internal plant processes.

Jan 1, 1939

Jan 1, 1971

By J P. Sykes, T C. McCuaig, M Jessell, A Trench

The election of Donald Trump and the Brexit referendum herald a shift towards a tighter definition of economic value, at the expense of the broader value concept of sustainable development; as well as a rise of protectionism, reversing a long-term trend of globalisation. However, the situation is complex, especially over the longer term in which mine project development and exploration operates. The minerals sector should proceed with caution. A greater focus on the local impacts of mining may be strategically beneficial, not only to mitigate against a potential protectionist future, but also because sustainable development has become more ‘localist’ via the concept of ‘social licence to operate’, whilst globalisation also seems to provoke increased ‘localist’ sentiments (known as ‘glocalism’). Localist strategies, therefore, seem a good hedge against multiple political futures. By contrast, moving away from sustainable development appears strategically riskier. Not only are ‘unsustainable’ activities, such as pollution and civil rights infringements harder to reverse, but a movement towards a more sustainable global economy may already be predetermined, even if the journey there may seem oblique. It appears that the increased economic development that is coveted globally is intrinsically linked to a rise in environmental and social consciousness.CITATION:Sykes, J P, Trench, A, McCuaig, T C and Jessell, M, 2017. Charles Dickens on the (potentially) changing role of globalisation and sustainability in the long-term future of mining and exploration, in Proceedings Tenth International Mining Geology Conference 2017, pp 239–256 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Sep 20, 2017

By Lulie H. Crump

Salient information on reserves, production, and consumption of fuels and energy by State is summarized in this Bureau of Mines publication. Reserve and production data are shown for each of the fossil fuels (coal, crude oil, natural gas liquids, and natural gas) and for uranium. The consumption data of each of the major consuming sectors (household-commercial, industrial, transportation, electric power, and miscellaneous) are broken down by energy source (coal, petroleum, natural gas, hydropower, and nuclear). In addition, total energy consumption in the Nation in 1974 is compared with consumption in 1973 and 1975 (preliminary data).

Jan 1, 1977

By F. W. Lee

This paper purposes to outline briefly results of seismic measurements made in the vicinity of blasts in a mine and in open-quarry operations. It endeavors to examine the amplitude and frequency of such vibrations as influenced by the loading, geology, and distance from the source and includes comments on factors that may index the destructiveness of a vibration and a method for measuring the stresses produced. There seems to be no simple mathematical analysis of the transmission of seismic energy through the ground, and experimental observations are at present most feasible. SEISMOLOGIC INSTRUMENTS Instruments developed by the Bureau of Mines for recording ground vibrations from quarry blasting comprise a new type of seismometer, oscillators, and a recording oscillograph. The seismometers respond to vibrations reaching them through the earth and transmit their characteristics by electric current to the oscilloglaph, where they are recorded by a beam of light on a moving strip of sensitized photographic paper. The seismometers are so constructed that their sensitivity to earth vibration can be controlled, thus keeping the amplitude of the recorded wave within bounds on the paper. Each instrument has been calibrated against vibrations of known intensity and frequency so that correction factors are known for the idiosyncracies of each unit. Moreover, each seismometer is calibrated in the field for its particular sensitivity setting at each blast. By these controls the actual movement of the earth due to vibrations of one ten-thousandth of an inch can be accurately measured.

Jan 1, 1936

By S Vink, A Wolhuter

Increasingly the community and government regulators are calling for æzero dischargeÆ mines. Some mining companies are beginning to explore ways in which they can transition to zero discharge. When striving to attain zero discharge, mines must consider multiple variables in addition to water quantity. These include climate regime, water quality and regional water budgets. This paper explores the drivers behind the concept of zero discharge mines and will use examples to illustrate the feasibility of attaining this goal.CITATION:Wolhuter, A and Vink, S, 2013. Is zero discharge a viable or useful concept in mine water management?, in Proceedings Water in Mining 2013 , pp 329-334 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Nov 26, 2013

Flow Sheet Simulation of Municipal Waste Treatment Processes

Sep 13, 2010

By Thomas J. Peters

In 1985, at the request of the U.S. Bureau of Land Management, the U.S. Bureau of Mines studied a 17,320-acre portion of the 52,143-acre Little High Rock Canyon Wilderness Study Area (CA-020-913/NV-020-008) in order to evaluate its identified mineral resources. The study area is located in Humboldt and Washoe Counties, NV, about 42 miles north from Gerlach. Three areas of epithermal alteration, similar to alteration associated with disseminated gold deposits, were found in the study area. One of the areas occurs along a northeast-trending structural lineament. Southwest of the study area two gold prospects undergoing active exploration, as well JS a gold deposit being prepared for production, occur along the same lineament. The Bureau of Mines examination, however, did not find evidence for gold resources in the study area.

Jan 1, 1987

By J. Brent Hiskey

Thiourea is a reagent capable of complexing gold and silver. With the proper oxidant, thiourea can effectively dissolve metallic gold and silver. A thiourea leaching system possesses potential advantages over conventional cyanidation including acidic solutions instead of alkaline, cationic complexes in contrast to metal-cyanide anoionic complexes, and faster leaching rates with acidic solutions of thiourea. Generally, the rate of metal dissolution in thiourea solution is fastest when ferric ion is employed as an oxidant. Acidic thiourea solutions for certain applications could offer a nontoxic and noncorrosive option for processing gold and silver. This paper provides information regarding the fundamental chemistry of the acidic thiourea system, and reviews the dissolution of both silver and gold in acidic solutions of thiourea. The recovery of gold and silver from acidic thiourea solution is discussed.

Jan 1, 1981

By M. K. Elmouttie, G. V. Poropat

Mapping of exposed rock walls provides data on geological features such as joints, bedding planes, faults etc critical to the economics and the safety of mine operations. Traditional, manual methods of mapping can be time consuming, error prone and limited in their coverage. New methods have been developed to map exposed faces remotely and safely however the benefits of these methods are only fully realised when exposed structures can be quickly and easily mapped using automated methods. This paper describes the application of an automated method of analysis of 3D images that provides users with the capacity to map exposed structures automatically. The method is based on the use of vector classification methods used in some neural network systems and provides rapid and reliable identification of exposed planes. CSIRO Exploration and Mining is applying these methods to 3D images for a range of applications from pit mapping to machine automation.

Jan 1, 2006

By Kathleen Lagnese, Srikanth Muddasani, Kashi Banerjee, Carla Robinson

"Mine water generated from underground coal mining operations contains both dissolved and particulate solids. Dissolved solids primarily consist of sodium, calcium, magnesium, potassium, chlorides and sulfates. When discharged to a receiving stream without treatment, these constituents create a potentially toxic environment for aquatic life.A case study is presented to discuss how a centralized treatment plant treats mine water from six locations to meet discharge limitations for chlorides. Located in West Virginia, this facility consistently achieves less than the National Pollutant Discharge Elemenation System (NPDES) permit limitation of 218 mg/L chlorides in the discharge while generating almost zero liquid waste. The dissolved solids concentration in the influent ranges between 5,000 and 10,000 mg/L, with chloride concentrations of 1,000 to 2,000 mg/L and sulfate concentrations of 2,000 to 6,000 mg/L.The mine water is treated using advanced treatment technology to produce clean water for discharge or reuse. The treatment process comprises aeration, softening, filtration, reverse osmosis (RO) reject softening, evaporation, crystallization, final effluent remineralization and sludge dewatering. The solid waste generated in the treatment process is landfilled on site. The leachate is sent back to the facility’s thermal treatment process. Because no liquid waste leaves the property, this plant is termed a zero liquid waste (ZLW) facility.The advanced water treatment system was built to meet a new 218 mg/L regulatory limitation imposed by the West Virginia Department of Environmental Protection for chlorides discharged to surface waters. The system is designed to treat a maximum flow of approximately 795 m3/h (5 million gpd) of mine water. The treatment process utilizes RO membrane treatment to achieve the effluent criteria, and evaporation and crystallization technology to manage the RO concentrate from the water treatment process. As a result, the system produces clean water for discharge while generating zero liquid waste. The effluent water can be used for industrial purposes or discharged to a receiving stream. A water impact index (WIIx) study indicated that discharge of this high-quality water into the Monongahela River watershed may improve the water quality for downstream water users. The waste produced in the treatment process, including softening sludge and salt, is disposed of in an onsite landfill. Currently, the plant is treating at an average flow of 490 m3/h (3.1 million gpd) of mine water with an average influent chloride concentration of 1,530 mg/L and an average effluent chloride concentration of 11 mg/L."

Jan 1, 2014

By Thiago Pinto Silva

Este estudo teve como objetivo investigar o efeito da substituição da dolomita por magnesita como fonte de MgO no processo de sinterização. Em testes realizados em escala piloto, observou-se que a utilização de magnesita eleva a resistência mecânica do sínter. A diferença de resistência foi decorrente da formação de uma solução sólida entre magnésio e ferro durante a sinterização. No caso da dolomita, que é fonte tanto de cálcio quanto de magnésio, a solução sólida Mg-Fe promove o encapsulamento do cálcio no seu interior, o que dificulta a formação das fases mineralógicas que promovem o endurecimento do sínter. Assim, a participação do cálcio na formação das fases ligantes é inibida, limitando a resistência mecânica obtida. A magnesita, por sua vez, não apresenta cálcio em sua constituição, sendo esse elemento adicionado via calcário. Dessa forma, o efeito do encapsulamento do cálcio não ocorre, havendo grande disponibilidade desse elemento para a formação de fases ligantes, permitindo a obtenção de níveis mais elevados de resistência mecânica do sínter. Portanto, a substituição da dolomita pela magnesita mostrou-se viável, desde que a granulometria seja similar à da dolomita, com grande potencial de melhora produtiva da sinterização industrial.

Oct 30, 2017

By H. L. Riley

Cleaning and handling of fine coal are generally conceded to be more difficult problems than preparation of the coarser sizes. Increased mechanization in the coal-mining industry has, in general, resulted in an increased percentage of the fine sizes in the total coal mined. If the coal fines are cleaned by wet methods, the minus-1/16-inch square-mesh particles cause most of the sludge and slurry problems encountered in preparing wet coal. Equipment that separates coal from refuse on the basis of specific gravity is not efficient on sizes that, because of their fineness, do not follow the same laws of hindered settling as the larger particles. Probably the best solution of fine-coal cleaning problems is to use other methods, such as flotation, that utilize other physical characteristics than those determining hindered-settling ratios. Regarding the type of flotation known as the Elmore vacuum-flotation process there has been a scarcity of data and information available in this country. An investigation has therefore been made to obtain additional date and information on this process under laboratory conditions. During this investigation an effort has been made to evaluate the relative efficiencies of vacuum and mechanical laboratory froth flotation cells. The investigation included float-and-sink, screen-sizing, and flotation tests on 2 different samples of 14-mesh to 0 raw coal and an a sample of slurry from the settling-tank overflow of a typical washer. One raw-coal sample was obtained from the American bed and represented a type of coal that is relatively easy to clean. The other raw-coal sample was from the Mary lee bed and represented a type considered difficult to clean.

Jan 1, 1954

By G. Andrews

This case study details the process that was used for project planning and permitting for the Greens Creek Mine, located near Juneau Alaska, as seen through the eyes of one of the primary environmental consultants. This case shows how a Company could involve the public and the agencies in the early 1980's and develop a project sensitive to concerns expressed with a high level of environmental protection. Comparisons are made to the current environmental permitting situation. Initial baseline studies performed during the exploration phase provided helpful information for more detailed environmental work in 1980-1981 as planning and permitting formally got underway. Since the mine was in a National Monument and abuts up to a designated wilderness, the Monument Manager administered the project for the lead agency, the USDA Forest Service. Planning and permitting progressed smoothly to a Final Environmental Impact Statement (FEIS) in 1983. Metal prices were depressed when the FEIS was completed and the project permitting proceeded slowly. Ownership changed several times in the mid-1980's. New owners re-evaluated the project and suggested five changes that required a supplemental EA prior to development. The project was fully permitted and started construction in 1988. Operation began in 1989. Today the environmental process in southeast Alaska is now much more complex, detailed, expensive, and time consuming than in the early 1980's. Significant issues discussed that may impede development and operation include overlapping agency jurisdictions, personal agendas of agency staff, conflicts between agencies that impede project progress, changing regulations, and a well organized environmental opposition.

Jan 1, 1993

By Philip C. Good

Red mud residue from Bayer process treatment of Jamaican bauxite was dewatered in batch and in continuous centrifuges. Solids content of the residue was increased from its original value of 20 to 25 percent to about 40 percent by centrifuging. Clear effluent amounting to approximately 40 percent of the slurry liquid was recovered containing dissolved alumina and soda values for potential recycle to the alumina plant" Addition of a chemical flocculant to the centrifuge increased capacity by about 35 percent. Manufacturer's estimate of large-scale equipment requirements, based on data collected in this investigation, was that a proposed installation for dewatering 16,000 tons per day of Jamaican red mud would require twenty-two 24-by 60-inch solid-bowl-type centrifuges. Cost analysis of a proposed installation, based on a Jamaican red mud tonnage of 16,000 per day, is included also.

Jan 1, 1968

By W. Holdsworth

The flotation mill of Dentonia Mines, Limited, at Greenwood, B.C., went into operation on April 20th, 1934, and by October 11th a total of 15,000 tons of ore had been treated. It is intended in this paper to describe briefly the operation and to give some of the operating data which have been gathered. The metallic minerals in the Dentonia ore are pyrite, chalcopyrite, galena, and, occasionally, native gold, and the gangue includes chloritic material, vein quartz, and calcite. Pyrite makes up about 90 per cent of the metallic content of the ore, in which it is disseminated as irregular grains and well-formed cubes. An average analysis of the ore is: gold, 0.27 oz. per ton; silver, 1.73 oz. per ton; copper, 0.12 per cent; lead, 0.31 per cent; and zinc, trace. From the mine ore-bin, situated near the portal of the tunnel at the mine, the ore is hauled by motor truck to the mill, a distance of three-quarters of a mile, and there dumped into the receiving bin, which has a capacity of fifty tons. The hauling is done during one eight-hour shift, commencing at 7 a.m. The maximum size of the ore fed to the mill-bin is ten inches. Lumps larger than this are broken by sledge hammer to pass through grizzly bars, spaced ten inches apart, installed above the bin. The ore is drawn from the bin by a 30-inch, 6-ply conveyor belt, 18 feet 6 inches long. In the near future, when the cross-cut tunnel is completed, the ore will be trammed to the receiving bin. This will effect a considerable saving in cost. At the same time, the bin will be set back several feet, so that the length of the conveyor belt may be doubled. This will make efficient ore-sorting possible, and so ensure a minimum of waste rock in the mill feed.

Jan 1, 1935

The 28th annual American Mining Hall of Fame Awards Banquet and fundraiser sponsored by the Mining Foundation of the Southwest will be held at the Marriott University Park Hotel, Tucson, AZ on Saturday, Dec. 4, 2010. The Mining Foundation of the Southwest is a nonprofit organization whose objectives are public education about the mineral industries, and recognition of outstanding accomplishments in and contributions to the fields of mineral and fuel resources. Funds are being raised to the support the foundation?s educational programs. Among these is the Educational Outreach Program operated jointly by the foundation and the Arizona Department of Mines and Mineral Resources.

Jan 1, 2010

By F. G. Horino

This report presents the theory and design of a stiff loading machine used by the Bureau of Mines. The machine incorporates three high-strength steel columns as the restraining member in parallel with the specimen. The theory presented gives the basis of design and the dimensions of component parts of the machine. Laboratory verification of the theoretical stiffness is described using three different setups involving a hydraulic jack and spacers and confirms the stiffness calculations to within 1 percent. Experimental techniques, testing procedures, and special equipment designed for determining the complete stress-strain behavior of NX cores of both hard and soft rock are described. Typical test data are presented as force-displacement curves for two rock types, a marble and a granite.

Jan 1, 1972