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By C D. Rose

"The primary objective of this paper is to demonstrate a different approach to predicting and verifying mechanical sampling system precision. Early in the year 2011 an experiment was conducted to evaluate the sampling precision being obtained by a three-stage falling-stream mechanical sampling system for coal owned and operated by Peabody Energy. This system collects samples from lots averaging approximately 14000 t being loaded onto rail cars at a flow rate averaging about 9000 t/h. In phase 1 of the experiment, a total of 60 increments were collected in a two day period at preassigned intervals using a cross-belt sampler located on a conveyor belt feeding a silo upstream of the sampling system under evaluation. Coal variability parameters were calculated from the resulting laboratory analysis data using the gauge-invariant fractal model developed by the author.Estimates of precision of the three-stage system as a function of the number of increments were calculated using the variability parameters determined in phase 1. In phase 2 of the experiment, duplicate samples of 30 lots of coal were taken by the three-stage sampling system, enabling calculations of the precision being achieved by the system. Phase 2 precision estimates are in reasonable agreement with those of phase 1. Conclusions drawn from the experiment include the following: Experimental variograms or the equivalent correlograms are essential in understanding sampling issues and for designing a sampling system to meet specific precision requirements. Consensus coal sampling standards provided by ISO and ASTM may be improved by treating all stages of a mechanical sampling system as æsamplingÆ rather than considering downstream sampling stages as æsample preparationÆ, to be treated in a separate part of the document. The coal industry would profit from use of methodology for routinely monitoring the overall measurement precision and the precision of the individual components of measurement: sampling, sample preparation and laboratory testing. This would not only give necessary credence to the measurement results but would also no doubt, lead to more efficient sampling system designs.CITATION:Rose, C D, 2012. Evaluation of precision being obtained by a three-stage sampling system for coal, in Proceedings Sampling 2012, pp 115-124 (The Australasian Institute of Mining and Metallurgy: Melbourne)."

Aug 21, 2012

By F Ramos

Conventional techniques for resource estimation generally involve the laborious analysis of variograms and the specification of parameters for covariance functions. In large deposits, construction of resource models and their update require significant amount of manual work, expert knowledge and time. In this paper we take a machine learning view to the problem of resource estimation. This is a non-parametric Bayesian method, leading to automatic parameter estimation (learning). Through Bayesian learning, the parameters of the model can be obtained by optimising a quantity known as the marginal likelihood. The main advantage of this approach over conventional maximum likelihood estimators is that the objective function incorporates the OccamÆs razor principle. This allows the comparison of different statistical models û for example, models designed with different covariance functions û and naturally penalises complexity, thus avoiding overfitting. Our technique presents significant flexibility for the definition of mean and covariance functions and permits the usage of more sophisticated models.The second contribution of this work is the formulation of a data fusion mechanism that continuously updates the resource model. As mining progresses, more information becomes available. For example, the hardness of the rocks can be measured while drilling blast holes, grades of ore and contaminants are obtained from cone logging. This information is in general available at a finer spatial resolution but can be more uncertain. The data fusion mechanism can seamlessly estimate the uncertainties of the different types of information and fuse them as new measurements are acquired. This procedure can significantly improve the quality of the resource model, defining new grounds for stochastic mine planning. We demonstrate the effectiveness of our approach in estimating iron ore deposits by integrating information about different grades.

Sep 26, 2011

By C. Karpuz, Y. S. Istanbulluoglu

This paper describes the results of convergence measurements conducted about five years for the re-use gate roadways at OAL lignite mine in Turkey. Double lignite seams separated with a marn layer, are mined with long-wall retreating mining system at the mine. Rib pillar has been abandoned and gate roadways were planned to be packed for the re-use of full extraction. Various packing systems have been attempted, namely three rows of woodenchock, one row of wooden chock plus concrete wall and concrete wall only. The re-use of maingate roadways packed with wooden chock yielded 62% of closure. Lastly developed concrete packing of 3 meters wide and specially developed support set composed of three friction props and a cap, which is a modification of yieldable set, have successfully maintained the main and tail gate roadways stability with a total vertical convergence of 32%. Good correlation has been established between pack stiffness and floor heave as well as maingate and tailgate convergences. The elimination of rib pillars by re-use of gate roadways increased the coal recovery by 20% and decreased the development/production ratio from 0.065 m3/ton to0.022 m3/ton.

Jan 1, 1997

By Vincent Jue

In December 2009, the Italian High Speed Rail Network AV began running over the full 1000 km system length from Turin, at the foothills of the Alps to Salerno, on the seacoast south of the volcano Mt. Vesuvius. It runs through Alpine rivers, highly seismic active zones, mountains, river plains, and through some of the most densely populated areas in Europe as well as some of its most expensive real estate. The Italian High Speed Network?s technical/economic constraints and its regulatory/socio-environmental concerns well may mirror similar obstacles set to confront the nascent California High Speed Rail Program. The two types of constraints must be dealt with together to reach the best construction solution. It is estimated that more than 20% of Italian High Speed Rail Network costs were spent on ground engineering including over 150 km of tunnels, 200 km of viaducts and bridges and 650 km of embankments and trenches. However, it also is estimated that 25% of costs were spent on social and environmental integration of the new rail lines including over 6 square miles of green offsets, 160 km of anti-noise walls, and 300 agreements for socio-environmental work. This paper will look at four examples of innovative ground engineering solutions, each with its own intricate set of constraints: ? Foundation system for viaducts across the ?Po? and ?Ticino? rivers. ? Soil consolidation under railway embankments ? Requirement of short tunnels for physical and environmental reasons ? Construction of railway stations in a confined right of way

Jan 1, 2010

By Steve Kral

Commodity price down cycles are a fact of life in the mining industry. And companies pre-pare for them as best they can. Evenso, operations are still curtailed or closed during those cycles, profits shrink, layoffs are inevitable and many companies do not survive. However, one of the few good things that occurs during down cycles is the new, innovative exploration, mining and processing technologies that come about during hard times. To survive the lean times, the mining industry turns to improved technology to decrease costs and hold the bottom line. And, because mining is a cyclical business, each down cycle brings about technology improvements that carry over into the good times.

Jan 1, 2004

By D. McCarthy

This paper discusses the process involved in developing an optimum method of treating and removing heavy metals from water that have leached out from the native rock -prior to discharge back into the environment. Also designed into the system is a manner to stabilize the metals removed as a precipitate, so that they can be disposed of as a non-hazardous waste.

Jan 1, 1992

By S SSdbom

A comparison was made between chemical analysis and ocular mineral/rock classification in health-based risk assessment of historical mine waste produced between 1625 and 1975. Large parts of the mine waste are heavily weathered and secondary minerals are abundant. The field was divided into several areas from where composite samples were collected. Seventy-five mine waste samples were selected for chemical analysis (As, Cd, Co, Cr, Cu, Hg, Ni, Pb, V and Zn) and ocular mineral/rock classification (silicate, mica, granite/pegmatite, carbonate, iron oxide ore, sulfide ore, distribution between chalcopyrite, sphalerite and galena and distribution between pyrite and pyrrhotite). The waste has been produced in conjunction with mining a complex sulfidic ore with increasing iron oxide content (mainly magnetite) towards the northern part of the field. Elevated concentrations were found for Cd (average 26 mg/kg dw), Cu (average 3500 mg/kg dw), Pb (average 4100 mg/kg dw) and Zn (average 11 000 mg/kg dw). Large differences between average and median values indicated that the data was not normally distributed, ie the metals occur as discrete minerals (eg chalcopyrite, galena and sphalerite). The ocular classification indicated low carbonate content, chalcopyrite dominating over sphalerite and galena in most samples and an even distribution between pyrite and pyrrhotite. Both analytical and ocular mineral/rock classification data were combined into a common matrix that was evaluated using multivariate statistics. Principal component analysis (PCA) showed, for instance, that chromium and vanadium were mostly associated with harder minerals and rocks. PCA also indicated that a similar graphical picture could be obtained for chemical data and ocular mineral/rock classification data, respectively. The comparison indicates that ocular mineral/rock classification can replace or at least reduce the numbers of chemical analysis in health- based risk assessment of historical mine waste.

Jan 1, 2008

By John J. Sammarco

Mining has one of the highest annual average fatality rates among major US industries. Health and safety dangers have been inherent to mining since the early days of picks and shovels. Even though miners’ health and safety has improved over the years, mining is still one of the most dangerous occupations. Mining was traditionally a low tech industry. It is now driven by competitive pressures to go high-tech by using programmable electronics (PE) for machine control, atmospheric monitoring and material processing. The industry’s experience with the functional safety of PE is limited compared with other industries. Thus, PE is an emerging technology for mining that can potentially create or worsen hazards.

Jan 1, 1999

By J. F. Power

Returning the original soil material to the surface of smoothed mine spoils is n practical means of restoring agricultural productivity. Research has established that high-sodium spoils in North Dakota (a) must be covered with about 70 cm of soil material to achieve maximum production; (b) topsoil must be segregated and spread separately from subsoil; (c) potential production depends on the quality of the soil material returned; and (d) erosion and upward salt movement must be controlled for sustained production. Erosion is best controlled by reducing final grades as much as possible during the smoothing process followed by prompt establishment of vegetation. Almost half the nation's cool reserves are in the Northern Great Plains underlying several million hectares of agricultural land. Social pressures to return mined land to agriculture or other productive uses have resulted in recent enactment of state and federal legislation, which is intended to restore productivity to disturbed areas. All such legislation relating to the Northern Great Plains has stipulated that useable soil material be saved and returned to mined land after spoils are smoothed. This requirement immediately raises questions as to how much soil material is needed, what criteria are important in defining useable soil material, how is the soil material to be handled in the earth-moving operations involved, and how can replaced soil material be maintained and revegetation. Scientists at the USDA Northern Great Plains Research Center at Mandan, North Dakota have conducted research on the reclamation of disturbed lands since 1970. Initially this research was designed to identify and characterize those physical and chemical properties of spoils that are most restrictive to plant growth (1). Basically, they found that any properties of spoils that reduced the efficiency of storage and utilization of the limited precipitation received adversely affected plant growth. Thus, in the Northern Plains, revegetation of mined land was found to depend upon the management of factors affecting the availability of water to plants - the same as on unmined land. After the major problems in revegetation were identified, technologies were developed to circumvent the effects of the growth-limiting factors (2). Basically two approaches were identified by which plant growth-restricting properties of spoils could be corrected: (a) various amendments (gypsum, sulfur, Fertilizers, mulches, calcium chloride, etc.) could be applied to spoils to improve their ability to conserve precipitation and provide water for plant growth; or (b) undesirable spoils could be covered with suitable soil materials to reduce or alleviate adverse effects. The latter approach appeared to be more feasible in most instances And is the approach specified in current legislation. The remainder of this paper discusses research on the use of roil materials returned to spoils and summarizes the information obtained.

Jan 1, 1978

The Aluminum Co. of America raised its 99.5 percent unalloyed aluminum ingot selling price in March by 34 to 514 per pound. Other producers, including Kaiser Aluminum and Chemical Corp. , Anaconda Aluminum Co. , and Reynolds Metals Co., followed Alcoa's lead, raising their quotes to 51$. In late March, domestic merchants quoted ingot at levels ranging between 49.56 and 50.50 per pound. BISMUTH: Several domes tic dealers lowered their bismuth prices in recent weeks by 50t-606 to within a range of $5.60-$5.75 per pound; producers continue to hold published prices at $7.50.

Jan 1, 1977

By S. J. Lötter, J. T. Nel, W. Purcell

"SynopsisGlow discharge optical emission spectroscopy (GD-OES) is an analytical technique used in the analysis of solid, conducting materials. Though primarily of interest as a depth profiling technique on samples with varying layers of both conducting and non-conducting materials, it is also capable of rapid bulk analysis of homogenous, solid samples. GD-OES combines the advantages of ICP-OES (wide detection range, speed, and lack of interferences) with the solid sampling of XRF techniques. This allows the analyst to not only quantify the elemental composition of a sample, but to evaluate it in terms of homogeneity with depth, a field in which auger electron spectroscopy (AES) and secondary ion mass spectrometry (SIMS) have traditionally been the primary techniques. Although GD-OES does not replace these useful techniques, it does offer various advantages over them, making it an excellent complementary analytical tool.In GD-OES analysis, a low-pressure glow discharge plasma is generated with the sample material acting as a cathode, accelerating the cations in the plasma towards the sample surface. This bombardment causes the sample material to ‘sputter’, essentially knocking free atoms or molecules of analyte material, which are then drawn into the plasma where they are excited. The light emitted by this excitation is then diffracted to separate the wavelengths emitted by the specific elements and detected by a spectrophotometer. The intensity of the signal is directly proportional to the quantity of analyte element present in the sample, allowing simple calibration and quantitative determination of the elements. Technological improvements made in the past twenty years or so have significantly increased the usefulness of GD-OES for surface analysis. Faster plasma stabilization and start-up allow for the quantification of surface layers as thin as 1 nm. Sputter rates have been accurately measured for many common materials, allowing them to be built into software libraries in the instrument’s control software. This dramatically expands the usefulness of this software and the ease of performing analyses.GD-OES analysis of nuclear materials allows for the rapid determination of the elemental composition without the requirement of initial dissolution. The thickness of any corrosion layers on nuclear materials can also be determined."

Jan 1, 2015

By M. Guzman, S. B. Thais, M. F. Obispo, M. R. Arribasplata

One of the greatest environmental issues related to the development of the mining activity is the generation of Acid Mine Drainage (AMD). Many methods have been developed for AMD treatment, being wetlands a good option for heavy metal removal. In this sense, the implementation of artificial wetlands for the treatment of mining effluents would seem to be an environmentally friendly alternative. In this paper, we present the results on the elimination of heavy metals (Cu, Zn, Pb and Fe) using two Peruvian native species such as Schoenoplectus californicus (C.A. Mey.) and Phragmites australis (Cav.) Trin. Ex Steud. The results show that Schoenoplectus californicus preferentially removes copper (82 and 90%), lead (88 and 92%) and iron (28 and 69%), whereas Phragmites australis removes copper (68 and 87%) and zinc (53 and 95%). Likewise, it is observed that the Schoenoplectus californicus mainly retains the ions in its root, copper (89%), zinc (84%) and iron (76%). While the Phragmites australis accumulates iron (62%) and copper (74%) in the steam and root part respectively

Mar 2, 2022

A method for the detection and analysis of tin in cassiterite ores is discussed. An empirical relationship was established between the tin content of an ore sample and the percentage absorption that this sample produced in a Mossbauer experiment. The time taken to complete an assay with this method is much less than with any of the methods currently in use. The equipment can be adapted readily for use in the field.

Jan 1, 1969

By I. J. Barker

Keywords: Submerged-arc furnace, plasma furnace, d.c. furnace, scale up, Søderberg electrodes, smart grid, demand side management, load shedding This paper argues that the scale up of furnaces and the supply of electricity are going to be two major issues that will affect the ferro-alloy industry in the near future, and that economic factors will drive this development. The most common type of furnace for producing ferro-alloys at present is the submerged-arc furnace with three electrodes, fed from a three-phase a.c. electrical supply. The scale up of this technology has now reached a fundamental constraint, which is caused by the electrical reactance of the secondary circuit. If the economy of any further scale up is to be achieved in the future then a different technology will have to be used. The supply of electrical power in future is likely to become a more complex issue than it is at present. Existing submerged-arc furnaces tend to run at fairly steady loads, but the ability to swing the load under demand-side management may offer advantages, and may allow a furnace to get cheaper power from the organisations that supply this power. This will have to be counterbalanced against the nuisance factors incurred by having a varying load in the operation of the furnace. Various options are therefore discussed in this paper. The possibility of scale up of Søderberg electrodes is discussed, as well as the use of d.c. power and multiple electrodes. Some of the issues with load swinging are also examined. A particular scenario is also briefly presented to show that considerable further scale up of ferro-alloy furnaces is still possible.

Jan 1, 2011

CAPTAIN JOHN H. BALLAMY John H. Ballamy, Captain on the Regimental Staff of the 103d Engineers, was killed near Fismes, on August 9, 1918. Captain Ballamy was born at Plymouth, Pa., in 1886 and graduated from the High School of that town in 1903. In the following year he began work as a coal miner, and at the same time began the study of mining engineering in the evening and any other spare time. He continued this diligent and energetic practice for many years. For sixteen years he continued in the employment of the Delaware, Lackawanna & Western Railroad Company's coal mining department, first as a practical miner, next as rodman on the survey corps, of which he soon became chief, then draftsman and mining engineer in the company's office. In January, 1916, he was promoted to the position of district engineer in charge of mining engineering work. He became a member of this Institute in September, 1917. CAPTAIN JOHN H BALLAMY. Captain Ballamy's military experience began at the same time as his engineering practice. He was a charter member of Company A, Engineers, N. G. P., which was organized ten years ago. He saw service on the Mexican border as First Lieutenant of this Company, and remained in that position until November, 1916. In July, 1917, he was again called into service and was sent to Camp Hancock, Ga., with the 103d Regiment of Engineers. Before joining this regiment he attended a school for officers at Fort Sill, Okla., where he received special training in field fortifications. In December, 1917, he was commissioned Topographical Captain on the Regimental Staff, and in April, 1918, preceded his regiment by about six weeks to France, where he again attended an officers' training school. He rejoined his regiment on July 15, near Chateau Thierry and was killed near Fismes on August 9, 1918.

Jan 11, 1918

By B Wentzinger, Y Keulemans

This paper presents the results of a field study designed to assess the impact of vane rotation speed on the estimated undrained strength for two Australian bauxite tailings storage facilities. The vane test results are assessed against cone penetration and dissipation tests results to identify if partial drainage may be an issue. An innovative tool capable of measuring pore pressures during vane shear testing, the Piezovane™, is introduced as an improvement over the standard field vane to assess drainage conditions in real-time.

Jul 1, 2021

By Michael Bauer

Increases in productivity and improvements in mining occupational safety and health are intrinsically linked. Over the past years, the German Hard Coal Mining Industry has been able to accomplish both: an increase in coal production and, at the same time, a significantly reduction of accidents. This success has been achieved by advances in technology, better organization and investment in people. Since 1990 productivity has more than doubled, while the total number of accidents has been reduced by more than 90%. Further development started initially with the mechanisation of the winning and drivage technology. Innovative technology and standardisation of the mining equipment were one reason for the increase in productivity and reduction of the accident rate. Therefore this technical development was not only one important pillar of the TOM model explicated later but also the requirement for the successful development of the other pillars. In addition to further developing this innovative technology it was possible to realise procedural and organisational improvements. As a result, the above achievement is based on implementing the three pillars of the so-called "TOM" model (technology, organization, ?Mensch? = human). To increase safety, improve performance, raise awareness and change of employees? attitude, the following technical and organizational requirements have been introduced: ??New innovative technology and procedures, standardized techniques and better equipment. ??Measures to revise or redefine the organizational structure, processes and systems of work, which were then integrated into the company policy and procedures as a company management tool. ??Personnel measures (investment in people). These include, improving motivation and behaviour, training, communication to raise and to change awareness of safety issues. Success in Occupational Health and Safety is not an automatic or self-regulating process. It needs hard work to make improvements and it must be treated as a recurring cyclic process. As a result of the above, occupational health and safety has become a natural part of daily work in the German Hard Coal Mining Industry. This could only be achieved by the unconditional "commitment" of all managers and employees to the issues, coupled with discipline and responsible action. Further improvements towards the ultimate aim of "zero" accidents are only possible by mutual involvement in implementing the ?TOM? (technology, organization and ?Mensch? human) model.

Aug 1, 2013

By G. Bierie

The conveying of bulk materials is prone to problems. These problems can reduce the capacity and efficiency of the plant, and even threaten the health and safety of the workforce. This presentation will look at new conveyor technologies systems, and how, used separately or in combination, they can improve material handling.

Jan 1, 2007

By P. J. Rowsell, M. D. Waller

Paper presented at a meeting on: Artificial intelligence in the minerals sector, held in Nottingham, UK, 20 April 1993. The applications of artificial intelligence systems in the upstream petroleum industry are reviewed. Particular emphasis is placed on current and potential applications in drilling engineering. Several recent advances in drilling technology have led to a large increase in the quality and volume of data available. This combined with the escalating cost, particularly of off-shore operations, is testing the traditional reliance on the skill and judgement of rig operators. AI systems offer enormous scope in enhancing and aiding the performance of these operations

Apr 1, 1994

By K. Olsen

As aluminum alloy usage in automobiles grows, there are increasing demands on recycling processes and facilities to deal with mixed alloy automotive aluminum scrap. These processes and facilities strive to produce near virgin aluminum stock, which can be relatively costly and difficult. One alternative is to use physical processing methods to upgrade the scrap properties instead of chemically refining the scrap. The Impulse Atomization Process (LAP, patent pending) is a new process for making metallic and ceramic powders. It can produce fine homogeneous microstructures in scrap aluminum alloys due to high undercooling and rapid solidification. The particles have a very narrow size distribution and are in a convenient form for consolidation. This paper compares and contrasts the microstructural features of Impulse Atomized. and quenched Impulse Atomized powders,' for both AL6061 and a scrap aluminum alloy composition.

Jan 1, 1995