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By C. A. Cole

This work consists of research in cable fault location and the construction of four field-test units based on the research. Swept-frequency sounding of mine cables with RF signals has been the technique most thoroughly investigated. The swept-frequency technique is supplemented with a form of moving target indication (MTI) to provide a method for locating the position of a technician along a cable and relative to a suspected fault. Separate, more limited investigations involved high-voltage time domain reflectometry and acoustical probing of mine cables. Particular areas of research included microprocessor-based control of the swept-frequency system, a microprocessor-based fast Fourier trans-form for spectral analysis, RF synthesizers, transmit-receive switches, RF receivers, cable dispersion-compensation techniques, low-voltage multielement display systems, and techniques for injecting or recovering RF energy through cable walls in support of clamp-on fault locators.

Jan 1, 1982

In the extraction of level bridge pillars in the South Mine by square-setting methods the general practice is to work transversely from the hanging wall in narrow sections three or four sets wide to the depth of the bridge-usually three sets. When the working block attains an area of twelve square sets, sand filling is run in, either by pneumatic (Proceedings No. 123, 1941) or hydraulic methods, in order to control the settlement of the general area and prevent the development of undue weight in the stope. Upon completion of the filling operations, or coincident with them, ore breaking is resumed and the transverse section of the bridge pillar gradually reduced. A number of these parallel sections may be working at the same time.In preparing a block of sets for filling a great deal of paddocking is required, both to contain the filling and to preserve access to ladderways and ore chutes which may be situated at some horizontal distance. Stope paddocking until recently was constructed of 10 in. x 2 in. boards nailed...

Jan 1, 1942

By Akira Usui

The details in small-scale variability of the geological occurrence and chemical composition of ferromanganese crusts are not yet well understood, although the northwestern Pacific seamounts are believed to be among the most promising areas for rare metal resources. Our belief is that geological observations and geochemical analyses are still insufficient for economic evaluation or for discussion of depositional processes and environments. Our team, composed of geologists, mineralogists, geochemists, physical engineers, and microbiologists has attempted to utilize an ROV for in-situ measurement and for sampling of undisturbed and uncontaminated ferromanganese crusts at three typical seamounts in the NW Pacific near the Japanese Exclusive Economic Zone. The first ROV geological survey of ferromanganese crusts was successfully completed, and the ROV proved to be the most powerful, efficient and elegant method to date. The collected samples (more than total 1 ton of crusts, at more than 100 sites along a total of approximately 10 km of survey lines) were most suitable to analyze water-depth dependency and secular variation of their composition. The intact surfaces of crusts, collected without the usual abrasion caused by dredging, were also valuable for microbial study of Mn oxidizing bacteria. The ROV sampling devices, however, can be improved with further sophisticated drills or rock saw blades in the future.

Jan 1, 2011

By Tom Treleaven

The success of any blast is dependent on the accuracy of the blast design and the field controls used on the shot. This point cannot be over emphasized because when the geometry is not measured and/or field controls are not properly implemented, it can often have devastating effects on the final blast results. Thus drilling accuracy, tiont row burden control, explosive confinement, energy distribution, explosive selection, timing and structural geology become critical parameters in the design of successful blasts. Understanding the actual dynamics of the blast and why certain results were achieved is the fast step in optimizing a blast design. As stated by R. Frank Chiappetta, “Of all the blast monitoring systems available today, high speed videography still remains as the best stand alone instrumentation system for blast diagnostics.” Over the past years I have analyzed hundreds of blasts using either high-speed lowcams (500 frames per second) cameras or standard digital (30 frames per second). These analyses confirm, without a doubt, that shot geometry, in combination with structural geology, is the most important factor in overall blast results. Drilling accuracy is the single most important component in efficient blasting. Having equal mass associated with an equivalent energy is the basis in which blasts are designed. When drilling inaccuracy or borehole deviation occurs, not only is the energy unevenly distributed, but the basis of all design calculations becomes invalid. Over the past several years, quarry and mining operations have employed the use of boretracking measuring devices to measure borehole deviation and hole toe locations. In cases of operations using top hammer drills, it was discovered that the amount of deviation was significant and far greater than they believed they had. Set up error, improper drilling techniques and bit wear were some of the contributing factors. Through video anaysis of boretracked blasts, blast results were directly linked to drilling ..accuracy. The comparisons here took into account blast design, energy factors and hole sequencing.

Jan 1, 2000

By Parker A. J, Muir D. M

Solutions of acetonitrile in water dissolve water soluble copper(I) chloride. Removal of volatile acetonitrile from the resulting solutions, by distillation with low grade steam, precipitates pure copper(I) chloride. This is used to purify a crude copper chloride sublimate from the chlorination of nickel matte but is applicable to other sources of copper(I) chloride. The pure product can be converted to pure copper(I) oxide, copper(II) oxychloride or pure copper metal directly.

Jan 1, 1980

By Wilson D, Kirkland J

Compressed air energy storage (CAES) uses low cost off-peak energy to compress air and pump it into pressurised underground storage. Expanding the air through a modified form of gas turbine generates electrical energy when required. While generating power, a CAES station consumes approximately one-third of the gas required for the equivalent installed capacity of a conventional gas turbine. Air can be stored in underground rock caverns, caverns in salt domes, or in aquifers. Existing CAES power stations use caverns mined out of salt domes. Aquifer storage for CAES has been proposed, but not yet implemented. The groundwater in the aquifer would be displaced during air injection and when required the air would be extracted using the natural hydro-static pressure. Victoria has no salt domes, but has aquifers onshore in the Gippsland Basin with geological dome structures of suitable depth, discovery pressure, porosity, permeability and caprock for CAES development. Field tests costing several million dollars would be required to prove the suitability. The most suitable aquifer is near Seaspray, where several dome structures exist. The aquifer, comprising of coarse sands capped by coal and mudstone, is some 600 metres deep with a hydrostatic pressure of 6.3 MPa. Computer simulation of injection and extraction of air from the aquifer under various combinations of horizontal and vertical wells, permeability and tubing head pressures indicated the largest aquifer structure had the capacity to sustain a 300 MW station. A well field comprising of 24 directionally driven wells with a horizontal exposure to the aquifer would achieve the air flow rates required. Using plant similar to that recently installed at McIntosh Alabama USA, would mean high capital costs compared to standard gas turbine plant. However, a review of modem gas turbines indicated that they could be easily and economically adaptated to CAES duty. Adapting a 120 MW gas turbine would give 344 MW output. A separate air compression plant would be used. Economic evaluations indicate that, for gas prices above $1.95 per GJ, a 344 MW CAES plant is more economic for intermediate/reserve load duty than simple cycle gas turbines.

Jan 1, 1992

By J-P Franzidis

A study was undertaken to determine the effect of five industrial frothers on the relationship between entrainment recovery and water recovery. The experiments were conducted using a Batequip rectangular 60 liter steel cell which was run in parallel with the first cell in a copper/silver prefloat rougher circuit. The concentration of the frothers ranged from 2.5 g/ton to 8.4 g/ton. The experiments were repeated at three different froth depths. A power function was found to fit this relationship with no discontinuity in the relationship caused by the changes in frother type and concentration and froth depth.

Jan 1, 2000

By Francisco Anglade

Dado que la simulación digital es una herramienta auxilar para los ingenieros de procesos -en tanto evalúa la factibilidad de un flowsheet propuesto y predice el efecto de una modificación para un flowsheet existente, su importancia también se extiende también a la evaluación de alternativas para las estrategias de control en los circuitos de la planta. En ese sentido, el presente trabajo señala los beneficios económicos y técnicos obtenidos en la planta San Rafael mediante el empleo de simuladores en los circuitos de molienda, chancado y concentración gravimétrica, los cuales permiten corroborar los cambios efectuados u optimizar los circuitos señalados de forma simple y rápida.

Sep 9, 2007

By R. K. Zipf

A method is presented for creating realistic numerical models for practical coal mine ground control. The method includes procedures to collect the necessary mechanical input parameters from a geologic core log, procedures to set up a model and procedures to interpret calculation results. The input parameters come from a detailed geologic core log and extensive point load tests of estimate rock layer strength. A suite of material property input parameters is proposed which allow the user to go from core log to numerical model inputs. Rock bolt anchorage properties are also linked to the material properties of each geologic layer in the model. Following this procedure leads to very realistic calculations of the rock failure process and rock support system behavior. These calculations in turn enable realistic comparison of the effectiveness of alternative rock support systems.

The pyrite-sphalerite-galena and barite orebodies at the Rosebery mine are concordant with the shale host rock and have been deformed into one system of folds with an associated axial plane cleavage. The folds are tight and overturned with east-dipping axial planes. Folds in the sulphide ore are commonly disharmonic, particularly between adjacent bands of different composition.Concentric style folds occur in the competent bands, e.g. pyrite-rich bands. Similar style folds are predominant in the less competent sphalerite-galena-rich bands and also in the shale of the host rock. The trends and plunges of the fold hinge-lines are variable but axial planes are of reasonably constant orientation throughout the mine area. The folds in the orebodies are of limited axial extent, approximating to conical folds, and are arranged in en echelon patterns. The fold system was possibly formed in one period of folding by heterogeneous strain that may have been caused by the presence of a mass of tectonically mobile sulphide ore. Lineations parallel to the ore/host rock contacts appear to reflect movement between the ore and the host rock during folding.

Jan 1, 1972

By E. L. McHugh, J. M. Girard

This paper discusses the results of two recent case studies in which high-tech prototype instruments were used. The first case study describes the results of a ground-based hyperspectral imaging tool used to map the geology of an open-pit mine highwall. The second case study outlines the use of interferometric synthetic aperture radar and how this type of radar can be used in a variety of geotechnical situations. These case studies are part of an on-going research project at the National Institute for Occupational Safety and Health’s (NIOSH) Spokane Research Laboratory. The project objective is to implement engineering controls and design methods in order to reduce the number of injuries and fatalities associated with slope failures at mining operations. Project personnel are hopeful that these new developments in technology will lead to better geotechnical monitoring and design in slope stability and other important areas of rock mechanics.

By Armstrong M

The Coal Mining Engineering Branch of the New South Wales (NSW) Department of Mineral Resources, in its continuing effort to improve coal recovery from underground coal mining operations, has undertaken a study of the mechanics of sub-surface deformation caused by caving of the extracted area behind retreating longwall faces. The strata movement was monitored by a multi-wire borehole instrumentation system consisting of mechanical anchors installed at different horizons in a borehole extending from the surface to the coal seam. The mechanical anchors were connected to the suspended weights on the surface by stainless steel multi-strand wires. The movement of these weights was monitored as the longwall face approached and retreated past the borehole. The anchors started subsiding as soon as the face retreated past the borehole and continued to subside until the subsidence levelled off when the face retreated 900 m past the borehole. The zone of major caving and bed separation extended to roughly 10 to 13 times the extracted seam thickness and high tensile strains developed inthis zone. The bulking factor of broken strata was less than 1.14 which indicated that the roof layers collapsed in big blocks. The goaf compaction was almost complete when the face retreat was 200 m. Low tensile strains prevailed in the strata overlying the zone of caving and bed separation.

Jan 1, 1986

By da Silva C A, Tenorio J. A S, de Assis R M, de Oliveira J R

For Fe-Mn alloy production, two reactions are responsible for this process: the MnO reduction in the slag and the carbon dissolution in the bath. The smelting-reduction process has been studied as alternative route to be used to produce alloy so as steel. This technical paper presents some initial studies to be used to determine the main ways that one can have for the mechanisms for this reaction. The limited factors like mass transport or chemical reaction were analysed. The Mn content in the bath were varied and it was concluded that by increasing the former, dissolution of Mn into the bath was increased, so as a reduction of MnO in the slag. For carbon dissolution, it was used a experiment with a stationary bar, this one was added into the bath, after ten minutes probes were catched, by temperature 1600¦C, for the dissolution of MnO, one graphite crucible was employed, after 45 min the slag and alloy were analysed. After the experimental part, some curves were plotted against time, based on these graphics, and kinetic analysis was made.

Jan 1, 1999

By Jonathan Peck, Doug Pollitt, Malcolm Scoble

Over the past 5 years the Department of Mining and Metallurgical Engineering, McGill University, has been involved in the performance monitoring of both percussive and rotary drills. Studies conducted in open pit coal and iron ore mines using microprocessor-based research and commercially available instrumentation resulted in the monitoring of at least 6 performance parameters while drilling vertical production blastholes.

Jan 1, 1991

By P. K. Hofmeyr

Base Metal (Cu, Ni, Mo, Zn, Co etc.) analysis traditionally has been very slow in conventional analytical laboratories which can lead to additional costs being incurred in waiting time of drill rigs or mining excessively off-reef. Recent developments in the automation of analytical laboratories now allow for very rapid turn-around times for base metal analytical data which can help reduce such costs as well as reduce the unit costs of the analyses themselves. 2.0 CONVENTIONAL ANALYTICAL LABORATORY PRACTICE Conventional analytical laboratories are necessarily are very manual. Sample preparation is slow and laborious, samples are moved from stage to stage manually and, typically, all samples are processed in batches so a sample which is the first to be, say, milled has to wait for the complete milling of the batch before it advances to the next stage eg. mixed with wax prior to pelletising for XRF analysis. Inevitably this results in long sample data turn-around times for laboratories handling large numbers of samples. Manual sample preparation can only be accelerated by increasing staff which increases costs and can lead to additional errors being introduced. Cleaning of sample preparation equipment, eg. crushers and mills, between samples is essential to avoid cross-contamination between samples and this is slow and labour-intensive. In manual sample preparation the correct sample numbers staying with the samples is totally dependent on the efficiency of laboratory operators. It is extremely difficult to detect when errors have occurred due to the switching of sample numbers during the sample preparation stages. Running duplicates and QC samples at best is only partially successful in detecting when sample number switching errors have occurred. Errors of this nature and cross-contamination problems due to incomplete cleaning of sample preparation equipment tend to occur when laboratories are working at pressure due to high sample numbers and when supervisors are not present during 24/7 laboratory operations which is often required on plant process control laboratories. These problems are common to all conventional analytical laboratories and their magnitude is dependent on the level of control and efficiency of QC systems practised by individual laboratories. The disadvantages of conventional manual analytical laboratories can be summarized as follows:- 1. Labour-intensive which is costly especially when multiple shifts have to be used during 24/7 operations.

Jan 1, 2005

By Mervin D. Marshall

A quick-reaction, mine permissible rescue vehicle (MERV) was developed for use by rescue teams. The MERV is a 6-wheeled, battery-powered unit with life support equipment and instrumentation; designed for a two-man team, with provisions for handling two victims or tools in a trailer. The vehicle is 100 inches long, 56 inches wide, and maximum height of 34 inches. It can be lowered down most mine shafts and has clearance to travel mine railways. The vehicle has power to all six wheels with power transmitted separately to either or both sets of wheels. Low-pressure, high-traction tires give the vehicle the ability to handle soft, muddy mine floors, flooded areas and significant obstacles, and can negotiate a 45% grade. Power and life support are sufficient for a 4-hour mission. The life support system is a commercially-available, approved unit currently used by MESA rescue personnel. A payout wire system provides communication between the vehicle and home base over a distance of 10,000 feet. On-board monitoring of carbon monoxide, methane and oxygen is provided, with master and individual alarms to warn of gas concentrations outside pre-set limits. A lightweight, water-tight trailer was developed for carrying victims or hauling tools and equipment.

Jan 1, 1979

By D. L. Petersen, C. R. Nelson, B. K. Nelson, B. D. Wagener

The Lafayette Bluff tunnel, currently under construction for the Minnesota Department of Transportation (MnDOT), will be among the widest highway tunnels in the United States. The 199-meter tunnel is being constructed in a closely jointed, variably weathered diabase rock mass. Cover above the tunnel crown ranges from 4 meters to 27 meters, and is less than the tunnel excavated width of 18.3 meters for about 60 percent of its length. These factors dictated special support and lining design, limitations on excavation sizes and required sequences for support installation. Tunnel excavation is by controlled blasting, with multiple top headings and bench. Rock support and lining consists of external portal beams, rockbolts and reinforced shotcrete. A final concrete lining provides structural support for the rock mass and the membrane waterproofing system.

Jan 1, 1991

By M. I. Mthenjane

"BackgroundThe paper discusses post-mining land use however, the essence of the topic is the emotional motivation behind the decisions related to mining investment and development. Therefore this is not a typical SAIMM technical paper about the science and techniques of post-mining land use. There are already numerous papers written and conferences held on this aspect of post-mine land use; the science is well understood, but the evidence of the practical application of the (environmental, social, and economic) science is sparse. At a recent conference held in November 2017 on the theme of ‘Science, Business, Society Dialogue – linking science, society, business and policy for the sustainable use of abandoned mines in the SADC region’, it was demonstrated through the delivery of several papers on the possible viable options of post-mine land use. The conference was structured in nine sessions, covering the following relevant topics:? Sessions 1 and 2: Nature and magnitude of the problem: raising awareness? Sessions 3 and 4: International experiences in remediation: case studies? Sessions 5, 6 and, 7: Technological solutions: converting liabilities into assets? Session 8: Implementing solutions: social and legal aspects? Session 9: Wrap up, lessons learned: conference resolution.Summaries of the key outcomes of the sessions are available for reference.The aim of this paper, accompanied by the video speech, is to provide a visualization of the possibilities of post-mine land use. Mining contributes approximately 7% to South Africa’s GDP - this is the lowest it has ever been and is attributable to both a diversifying economy and to poor mining and investment policy which has resulted in reduced investment in the sector. The objective of the paper is to highlight the opportunities, for succeeding and diversifying economic activity following mining and mineral extraction which can continue to sustain the livelihoods and wellbeing of communities and societies beyond mining.During mining, very few alternative and local economies develop. Dependence on mining and its value chain prevails until mining ceases. This idea is conveyed in Figures 1a and b."

Jul 1, 2019

Discussion of "The Ordering Transformation in Titanium-Aluminum Alloys Containing up to 25 at. pct Aluminum" by F. A. Crossley, Trans, TMS-AIME, 1968, vol. 242, pp. 726-30. Dr. Blackburn, in his response, pointed out that the c/a ratio of the Ti-26 at. pct A1 alloy quenched from 900°C is 1.6006 and not 1.5965 as plotted in Fig. 19. An error in transcription was made in preparing Table V of Ref. 1 (F. A. Crossley, Trans. TMS-AIME, 1966, vol. 236, p. 1174). The corrected Fig. 19 strengthens rather than weakens the argument that a martensitic transformation occurs in alloys containing from 15 to 18 at. pct Al. A Study of the Factors Which Influence the Rate Minimum Phenomenon During Magnetite Reduction, by P. K. Strangway and H. U. Ross, Trans. TMS-AIME, 1968, vol. 242, pp. 1981-88. Page 1883 Reverse Figs. 5 and 6. Sigma—Its Occurrence, Effect, and Control in Nickel-Base Superalloys, by J. R. Mihalisin, C. G. Bieber, and R. T. Grant, Trans. TMS-AIME, 1968, vol. 242, pp. 2399-2414. Pages 2403, 2407, and 2414 Arrows should appear on Figs. 4 and 9; a sigma is missing from Table IV; line 2, page 2414, change "case" to "cast". These are published correctly in the bound volume. Index, December Issue There were a few omissions in the Author Index. These have been corrected and published properly in the bound volume.

Jan 1, 1970

By Pfeifer H. C, Nicacio P. A D

Sinter has been used as part of the metallic charge in large-scale blast furnaces for many years with the well-known benefits in terms of productivity and fuel consumption. However, because of the high investment in a conventional sinter plant, small blast furnaces and the associated integrated mini steel plants have not taken the advantages of using sinter. Recently KTS Korf Tecnologia Siderurgica, a division of Mannesmann Demag Ltda in Brazil, has developed a mini sinter plant for which the investment is compatible with small blast furnaces. Consequently, it is of great interest to evaluate the economical impact of using sinter in such small-scale integrated steel plants. In order to compare two alternatives, ie 100 per cent ore and 70 per cent sinter in the blast furnace burden, mass and heat balances for the entire operation from sinter plant through the blast furnace and EOF-based melting shop, were performed to evaluate the final production cost of the liquid steel. It was found that, depending on the sinter feed price, substantial savings can be obtained with the use of sinter.

Jan 1, 1999