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To alleviate the hazard to personnel and danger to equipment caused by fires on large, mobile vehicles. The Approach: A system which automatically senses a fire at its early stage of development, warns the driver of the danger, and activates fire extinguishers in the zone of combustion, How It Works: The automatic fire protection system utilizes both thermal and optical sensors to detect the heat or light given off by a fire in the area of concern (Fig. 1). The system warns the driver of the hazard and then automatically extinguishes the fire with pressurized S-C class powder. The system can also be activated manually from the operator's cab or from ground level. Further, the automatic sequencing of the system can be manually overridden by the driver if he determines that the fire sensors have malfunctioned to cause a false alarm.

Jan 1, 1974

A mobile vacuum sweeper to remove loose coal and coal dust from underground coal mine workings was designed, built, tested, and evaluated. The design was based on an extensive test program. Pick up and conveying rates vs. air volumes, velocities, and nozzle shapes were determined for coal rubble in a laboratory pneumatic handling system. A gas/solids separation system was developed and tested in the laboratory capable of separating the solids loading from the vacuum system air stream to the very high degree required to preclude degradation of the ambient (mine) air. Two designs were made, one for belt conveyor and one for general district cleanup. The belt cleanup machine was chosen for test and demonstrated in an underground coal mine performing cleanup work in belt haulageways and on ribs.

Jan 1, 1975

By James M. Spear

Sample results suggest the only mineral resources in the study areas are placer gold deposits along the South Fork Kern River in the Woodpecker RARE II unit (fig. 1). These deposits, in Rockhouse Basin, total 4.5 Figure 1.--NEAR HERE. million cu yds (3.4 million cu m) of indicated subeconomic gold resources in four deposits of "older" gravel. Gold value in samples averages $0.36 per cu yd ($0.47 par cu m) and is as much as $4.44 per cu yd 1/. Cost of mining the gravel and recovering the placer gold is estimated to be more than $2 per cu yd ($2.62 per cu m) for a deposit of this size and type. Additional inferred subeconomic placer gold resources with similar grade probably occur in four other deposits of "older" gravel on which no mining claims were located. Placer gold occurrences on upper Trout Creek contain gold worth as much as $4.50 per cu yd ($5.88 per cu m) 1/. Average grade is much lower, and only about 1,000 cu yds remain (760 cu m). These occurrences do not constitute a resource, but may attract hobbyists not dependent upon making a profit.

Jan 1, 1982

By J. H. Jones

The original term of grant No. 1115174 was September 1980 through December 1983. An extended progress report, covering this time period, was forwarded to the Bureau of Hines in January 1984. The principal investigators were given a no-cost extension of their grant to cover the period January through December 1984. The report which follows covers this latter time period only.

Jan 1, 1985

By Robin P. Gardner

The development and use of short-lived radioactive tracer methods for the on-stream determination of residence time distributions in large-scale ball mills is described. Tests are reported on a pilot-plant ball mill with 0.43 m diameter and 0.86 m length and on an industrial mill with 1.83 m diameter and 2.74 m length. Tests with different tracer feed sizes indicate that the residence time distributions on both mills are independent of charge particle size. Similar tests are planned for a-large ball mill of 4.57 m diameter and 9.30 m length. No safety problems were encountered in these tests and none are anticipated in tests of the larger mill.

Jan 1, 1978

By Seppo Lähteenmäki, Pertti Koivistoinen, Jaakko Levanaho

"This paper describes the benefits and disadvantages of fully autogenous grinding when compared to grinding with steel grinding media. The study is a real case study based on a low tonnage, high grade mining project in a remote location in a developing country. The study compares the capital and operating costs of using either SAG mill, Ball mill, Crusher (SABC) or fully autogenous (AG) grinding circuits and produces an economical analysis of the project for both options. The economics have been developed for the overall project, including mining, processing, environmental and the infrastructure as well as for the additional cost of constructing a fully autogenous grinding circuit instead of the original plan of a SAG Mill, Ball Mill circuit.The paper also describes the development of the autogenous grinding circuit at Outokumpu Oy, Pyhäsalmi mine. This experience was used to design the autogenous grinding circuit for the case study. Pyhäsalmi Concentrator has over 30 years of experience in operating autogenous grinding circuits and therefore provides a sound base for the new circuit design.INTRODUCTIONGrinding of ore using steel grinding media is currently the most commonly used method in the mining industry. Autogenous grinding, ore replaces iron media, is also common especially in Europe and Africa. Iron ore industry in North America uses autogenous grinding in primary and/or secondary stages extensively. In gold, copper and other base metal industries, autogenous grinding is not as common, although there are operations where pebble grinding is or has been used in the secondary grinding stage. There are many variations of autogenous grinding in use in the mining industry. These variations include different mill sizes, mill length to diameter ratios, ore lump sizes, screening and pebble crushing configurations."

Jan 1, 2000

By D Wiseman, D Weedon, T Akroyd

Models of the size specific processes of particle collision, attachment and detachment have been combined in a form suitable for analysis of a full-scale flotation plant. The model is based on a first principal approach to particle collection by bubbles. Parameters considered include particle size, bubble size, particle contact angle, energy dissipation, entrainment and froth recovery. Using data structures configured within an Excel spreadsheet using æLimn: The Flowsheet ProcessorÆ, the model has been incorporated into a description of the individual cells within a simple roughing and cleaning flotation circuit. Simulated feeds of varying particle size distribution, feed tonnage and varying mineral hydrophobicity representing different mineral phases are presented to the model to produce predicted final concentrate grades and recoveries. Practical techniques for measuring many of the parameters included in the model are now becoming readily available. However, relating the terms included for contact angle, energy dissipation, entrainment (ie water recovery) and froth recovery to measurable parameters in operating plants remain as continuing challenges for research.

Jan 1, 2004

By Gino Vogt

In mechanized tunnelling operations performance, consumption and safety are main factors for jobsites. One of the most important components effecting these factors, especially in slurry TBM operations, are Slurry Treatment Plants (STPs). Inadequate/ suboptimally dimensioned and designed STPs create bottlenecks for tunnelling operation and jeopardize time schedules and performance. Inefficiently planned STPs could drastically increase consumption figures such as electrical power, bentonite, water and polymers, etc. Inaccurately selected and treated suspension properties can cause a high-risk potential for the whole job. This paper debates the relevant key parameters for STPs from start to finish of a project and its results in influencing factors from the manufacturer´s point of view.

Jun 13, 2021

A Robust Chemically Enhanced Electrostatic Separation Technology Physical separation processes such as gravity, magnetic and electrostatic separations are extensively used in heavy minerals separations. Electrostatic (aka High-Tension) separation facilitated by the conductivity differences, in particular, is used for separating rutile from zircon. Although electrostatic separation is effective, it is not efficient. It suffers from separation efficacy issues owing to sensitive variables such as humidity, surface contamination, particle sizes and the temperature of the feed and other equipment parameters. The variations in the process conditions especially with humidity, temperature of the feed and the mineralogy and surface impurities can cause significant reduction in the separation resulting in production rate losses and product quality issues. Cytec Industries has developed chemical enhancement technologies for electrostatic separation for rutile -zircon separation from the heavy minerals. The major advantage of our technology is its higher separation efficacy in the first pass, substantial energy savings and most importantly its ability to do separation at room temperatures. The bolt-on nature to the existing electrostatic also an added feature that reduces the capital expenditure significantly. The separation efficiency between rutile and zircon was increased as much as 8 - 11 per cent compared to control. It is possible to extend the chemical enhancer technology to problematic feeds and other mineral systems that are not easily amenable to conventional electrostatic separation.

Sep 13, 2010

By Bern Klein, Malcolm Scoble, Justin Widdifield, Andrew Bamber

"It has been suggested that the pre-concentration of ore underground can bring positive economic and environmental benefits to underground mining, particularly at extreme depth. The integration of mineral processing systems for coarse waste rejection and disposal into the underground mining environment has a substantial impact on the economics and operation of the mine. A case study for the integration of underground pre-concentration at Falconbridge’s Thayer Lindsley and Fraser Copper operations in Sudbury, Ontario is discussed, with particular focus on ore evaluation, system design, integration, and impacts on the operation. Conclusions as to the overall feasibility and potential impacts of underground pre-concentration are presented.INTRODUCTIONObjectivesA scoping investigation has been conducted for Falconbridge Ltd on the Fraser Copper Zone and Thayer Lindsley mines in order to develop a better understanding of the operations, and to do a preliminary evaluation of the potential for pre-concentration of the ore underground. The objective was to develop a conceptual design and evaluation of a pre-concentration system for each site. The results are to be used as the basis for a more detailed future study.Underground Pre-ConcentrationThe pre-concentration of ore to reduce the quantity and improve the quality of material transported to the processing plant is not a new concept and has been in practise at several mines including the American Zinc Company in Mascot Tennessee (Munro et al, 1982), the Sullivan Mine in British Columbia and presently at Xstrata’s Mt Isa lead-zinc mine in Australia, as well as at several PGM mines operating in the South African Bushveld. For each of these mines, a high degree of waste rejection was achieved at a coarse particle size with good metallurgical recoveries. The benefits arising from the surface pre-concentration of ore are well documented in the literature (McCullough et al, 1999; Miller et al, 1978; Munro et al, 1982; Schena et al, 1990; Sivamohan & Forssberg, 1991)."

Jan 1, 2006

By C. E. Wyndham

The occurrences of manganese In Alabama were reported to be widely scattered over the northeastern section of the State, and these were examined before a development project was started.2/ The most promising and available showings were chosen for further investigation, which include 1 deposit in Goshen Valley, 6 in the Rock Run area, and 2 in the northern section of Calhoun County. The work was performed by the Bureau of Mines from July 29, 1949, to February 17, 1950. The work consisted of power auger drilling 69 holes 3-1/2 inches in diameter and totaling 2,548.4 linear feet. The accuracy of samples from auger drill holes in this type of deposit was determined by sinking two shafts a total depth of 68.17 feet, from which channel samples were cut. Sixteen rotary core holes totaling 1,048.7 linear feet were drilled with a 3-inch, double-tube core barrel. Twenty-two diamond core holes were drilled with a 2-1/8-inch, double-tube core barrel and NX diamond bit. In addition to the above drilling 220.8 cubic yards of soil and rock was excavated by hand from 403.9 linear feet of trenches and 69.7 feet of test pita. A total of 206 samples were taken and analyzed for manganese, iron, cobalt, nickel, and insoluble.

Jan 1, 1953

By Richard F. Zaffarano

The Bureau of Mines compiled information for the nonspecialist about natural gas liquids recovery from hydrocarbon streams in natural gas processing plants. Attention is directed to the impact of the technology of processing and the quality of gas processed in view of the increased availability of natural gas for processing. Significant changes in product and market trends within the natural gas processing industry are highlighted. Fixed capital-plant costs for grassroots, refrigerated-oil absorption and conventional adsorption schemes, adapted from published studies, are presented giving ranges of cost estimates for medium-sized plants. Marketed products of the natural gas processing industry are briefly discussed in relation to automotive air pollution problems and approaches to their control.

Jan 1, 1970

By S L. Nicol, B J. Hogg, O J. Mendoza, S Nikolic, A Burrows

The top submerged lance (TSL) technology, developed in the 1970s, is now widely used for the processing of a range of materials. The key advantage the ISASMELT™ TSL technology provided was the ability to process feed materials in a highly turbulent bath, reaching close to equilibrium conditions, uniquely allowing for operation below the liquidus of the molten slag phase. The details on what happened below the liquidus line in the phase diagram became critical for the successful operation of the technology. During the development of the ISASMELT™ technology this led to a collaboration between the Process Technology group of Mount Isa Mines, now part of Glencore Technology, and the Pyrometallurgy Research Centre (PYROSEARCH) at The University of Queensland. The fusion of the phase equilibria research into the technology development allowed for understanding of the behaviour of molten splash, reliable tapping of the furnace, and the ability to operate the furnace with a refractory lining and achieve a year campaign life in excess of four years. The outcome has allowed for the highly successful adaption of the ISASMELT™ technology to recycling of complex feed streams necessary to drive circularity in our modern global economy.

Aug 21, 2024

By Zbigniew Zurecki

The selection of atmosphere composition is critical for controlling surface quality of reactive aluminum alloys during solution treatments. An improper selection of annealing atmosphere can result in surface blistering in AI-Mg and sub-surface depletion of lithium in AI-U ingots. To determine optimum atmosphere compositions for homogenizing A1-Mg and Al-Li alloys, Ii number of exploratory experiments were carried out in air, nitrogen, and carbon dioxide based atmospheres including reactive impurities or additive such as moisture and sulfur hexafluoride. This paper describes the influence of these atmospheres on high-temperature oxidation and sub-surface defects. The results are discussed in terms of the change in Pilling-Bedworth ratio.

Jan 1, 1996

By Herbert H. Einstein

Instability of rock slopes often occurs in the form of excessive movement of bodies that are bounded by discontinuities. The well known limit equilibrium analysis for wedges and blocks suffer, however, from procedural simplifications and from the basic deficiency of limit eguilibrium analysis--the rigid body assumption. Thus, stability analysis for 2-and 3-plane wedges with a wide range of additional features regarding failure modes and external forces have been developed. The deficiency, due to the rigid body assumption, was corrected by an approach that includes the effects or the in-situ stress field and of the stiffness of discontinuities. The final step in making limit equilibrium approaches more valid was achieved with the method of artificial supports which makes it possible to identify among all possible failure modes the critical one and to determine the corresponding factor of safety. The analytical development includes the creation of appropriate computer codes and routines for programmable pocket calculators.

Jan 1, 1979

The authors summarise the development and recent advances in the reconstruction and visualisation of three-dimensional objects from point data and describe applications to the reconstruction of orebody shapes from drill-hole and other data. In particular, Dijkstra's algorithm is proposed and implemented as a means of optimal reconstruction of complex orebody and topographical shapes from irregularly located sample data. The surfaces of the shapes are constructed from triangular tiles and the algorithms proposed by the authors are guaranteed to find the optimal set of tiles that "best" construct the surfaces on the basis of specified objective criteria. The algorithms are illustrated by applications to a complex silver/gold/zinc/lead deposit.

Jan 1, 2002

By John H. Perry

Strata III is a full-spectrum roof control system which provides the mine operator the ability to upgrade his roof control in place. The procedure is easily adaptable with current roof bolting techniques. To use the system, the operator starts by installing a special hollow core mechanically anchored roof belt during the roof bolting cycle. This bolt can be upgraded to a fully grouted tensioned rebar bolt by injecting StrataGee G-300, a special polyurethane grout, around the bolt through an injection port in the roof plate. This same bolt can then be used to inject RokLok binders for roof consolidation by pumping the binders through the core of the bolt. This concept in roof control was developed to provide the mine operator a flexible way to maintain roof control in areas which deteriorate over time, or must be kept open for long periods of time. Possible locations of use would be: longwall set-up rooms, recovery rooms, headgates, intersections, and belt entries.

Jan 1, 1987

By H. A. Taylor

Graphite is elemental carbon that crystallizes in the hexagonal system as six-sided platelets. It occurs naturally and is mined. And it can be made artificially from petroleum coke in the form of shapes (electrodes) and powders. The market for most kinds of graphite in most end-uses was good in 2004. The 2005 graphite market looks positive. The major graphite prices, as given in Industrial Minerals, remained unchanged throughout the year. The preliminary 2004 U.S. Geological Survey (USGS) prices for natural graphite showed almost no change for crystalline flake. They were $600/t ($544/st) in 2004 and$622/t ($564/st) in 2003. Mexican amorphous graphite was almost unchanged at $150/t ($136/st) in 2004 from$152/t ($138/st) in 2003.

Jan 1, 2005

By Colin Rawlings, Simon Pepper, Maria Karakitsiou, John Mathews, Peter Townsend, Russell Bowler, David Keeble, Christopher Darton, Scott Sadler

National Grid needs to maintain a connection between two existing electricity sub-stations (Beddington & Rowdown) in the Croydon (south London) area, and allow the replacement of two 275 kV cable circuits that are buried under roads. This is to be achieved using a single 400 kV cable circuit within a 10 km (6.25 mile) long, 3 m (9.8 ft) diameter high voltage cable tunnel which is being driven through water bearing Chalk, at depths ranging from 5 m (15 ft) to 80 m (262 ft), with four access shafts(12.5 m (41 ft) in diameter) ranging in depth from 10 m (31 ft) to 40 m (131 ft). The Chalk in this area acts as a source of public drinking water supply (PWS) and is protected by areas designated Groundwater Source Protection Zones. To minimise the groundwater risk the design and construction of the cable tunnel and shafts has paid particular attention to the construction materials used, including testing of these construction materials prior to use, developing construction methods (including the design of the Earth Pressure Balance TBM) and maintaining a groundwater monitoring & testing programme prior to and during construction to ensure the integrity of the Chalk aquifer is maintained as a drinking water source. This paper describes the tunnel &shaft design and construction in relation to these particular groundwater environmental issues which set new precedents for tunnel assessment, design and construction requirements in the United Kingdom.

Jan 1, 2007

By J. Jonas, J. M. Harrington, K. Wangerud, S. D. Fundingsland, J. G. Harrington

EPA NRMRL Mine Waste Technology Program and Region VIII Superfund office are jointly conducting an in-situ technology demonstration at the Anchor Hill Pit Lake, Gilt Edge Mine Superfund site. The goal is to develop in-situ treatment cost/performance data for potential application in long-term water treatment/management at Gilt Edge and similar sites. The pit contained 77,000,000 gallons of pH 3water with elevated metals, sulfate, and nitrate. The Green World Science® patented process for in situ treatment was implemented to isolate and sequester metals; create stable long-term water quality and restore a sustainable ecosystem. COCs have decreased more than 99%, and dissolved discharge standards were attained.

Jan 1, 2004