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By Junli Xu, Xianwei Hu, Kaiyu Xie, Liangxing Li, Zhongning Shi, Zhaowen Wang, Bingliang Gao, Aimin Liu

Al-Ti master alloys were prepared by aluminothermic reduction between the dissolved titanium dioxide and aluminum in cryolite melts at 960oC. The kinetic analysis by differential scanning calorimetry indicated that the apparent activation energy of the reaction of reducing titanium dioxide by aluminium is 22.3 kJ/mol, and the reaction order is 0.5. The products were analyzed by means of X-ray diffraction, X-ray fluorescence, scanning electron microscopy and energy dispersive spectrometer. Results from X-ray diffraction showed that the phase compositions of produced alloys are Al and Al3Ti. In addition, Al-Ti master alloys containing 2-6 mass% Ti were formed at different reduction time of 2-5h in aluminothermic reduction experiment.

Jan 1, 2015

By E. P. Ferrero

Crude oils from fields throughout the world are analyzed by the Bureau of Mines to determine the characteristics of the oils and their contribution to the petroleum resources of the world. Analyses are reported for 169 foreign crude oil samples from 122 oilfields in Africa, Asia, Australia, the Caribbean, Europe, North America, and South America. Tables show the geographic and geo- logic origin of the samples, names of companies that supplied the samples, annual production for the fields, general characteristics and analytical and computed data, hydrocarbon-type data, cumulative production of the larger fields, and references to sources of geological and field development information. The analyses were made by the Bureau of Mines routine method and comparisons may be made with more than 8,000 other such analyses.

Jan 1, 1972

By S. Kahraman

The correlations between the modulus ratio and penetration rate of rotary and percussive drills were statistically investigated using the raw data obtained from the experimental works of different researchers. An inverse power law was found between the modulus ratio and the penetration rate of rotary and diamond drills. The penetration rate of rotary drills and diamond drills decrease with an increasing modulus ratio. The penetration rates of percussive drills increase with an increasing modulus ratio. There are significant linear correlations between the penetration rates of percussive drills and the modulus ratio. In one of the cases of percussive drilling, a strong correlation between the penetration rate and the modulus ratio was found for the rocks having a porosity value lower 1.23 %. It can be concluded that the modulus ratio might be a representative measure of rock drilling efficiency. However, further study is necessary to check the validity of the derived equations for other rock types. The effect of porosity on the correlations between the modulus ratio and penetration rate needs to be further investigated.

Jan 1, 2003

By C. J. Cutler

Metallurgical accounting for toll treatment smelters pose a number of challenges. Multiple feed stockpiles have to be accounted for as part of the monthly recovery estimation. Moreover, multiple metallurgical intermediates make up part of the in-process inventory, which also influence the monthly recovery calculation. Errors propagate from the measurements of volumes, assays, moisture fractions and bulk densities in the various material types through multiple steps up to the point where the final recovery is calculated. These errors contribute non-linearly to the variance in the final recovery estimate. This paper develops the mathematical formulation for variance propagation in toll smelting operations, including the effect of in-process inventory, assuming measurement biases have been eliminated beforehand. Operational data from a Southern African copper smelter is used for a case study. The method of propagation of variance showed that uncertainties in stockpile assays were the main contributors to variance in the recovery estimate. Variance in the volume and bulk density uncertainties contributed a secondary, yet significant, proportion to the overall recovery variance. It was determined, for the given case study, that the recovery variance depended on the calculation method used and that variance propagation via the two-product formula was smaller than recovery variances calculated via the standard recovery formula. However, the probability that the two product formula will give inaccurate (versus imprecise) results is significantly more due to the practical difficulty of equiprobable sampling of tailings streams from smelter plants (which includes materials such as slags and flue dust). Recommendations are made on how to achieve a reduction in overall uncertainty for toll treatment smelters. Keywords: metallurgical accounting, copper smelters, pyrometallurgy, variance propagation, errors, precision, sampling

Jan 1, 2006

By R. W. Barnes

This circular presents results of a survey conducted by the Bureau of Mines to ascertain the extent to which dust-control practices are employed in the coal-mining industry. This survey was initiated because of increasing realization of the possible harmful effects of the inhalation of dust upon the health of coal-mine workers and the advent, during recent years, of new types of mining machinery and new mining methods that may have a direct effect upon the extent of exposure to airborne dust experienced by persons mining coal. Anthracite Mines The survey covered 169 anthracite mines that were operating from November 1, 1953, to July 1, 1954. It showed that large mines employing more than 100 men were doing most to control dust produced during mining.

Jan 1, 1956

The Kingsgate molybdenite pipes are considered on petrochemical data and field occurrence to be, possibly, epi-magmatic plutonic offshoots grading into hydrothermal bodies. There is reason to believe that the ore is derived from a highly acid granite of type similar to that of the tin bearing areas of northern New England. The mineralogy, microtextures and paragenesis of the ore are discussed.INTRODUCTIONThe Kingsgate Mining Field is situated in steep, heavily timbered terrain 18 miles E.N.E. of Glen Innes and 430 miles north of Sydney. Bismuth and molybdenum ores were discovered at Kingsgate (Yarrow Creek) in 1877. Subsequently some 50 pipes were developed yielding tonnages which at the peak of operations, 1905 to 1920, rivalled production from the rich deposits of northern Queensland.Attempts to revive the field have been made periodically and small parcels of ore have been forthcoming.' During World War II demand for piezioelectric quartz again focussed attention on Kingsgate but twinning and other imperfections of the quartz prevented all but a minor exploitation of the otherwise noteworthy crystals of this locality.There is reason to believe that the ore at Kingsgate is not exhausted through exploration and mining costs would probably be high due to the capricious nature of the pipes and to the irregular distribution of rich ore shoots within them.

Jan 1, 1962

By Francis D. Leathers

Four friction pile load test programs, including 23 tension tests and 9 compression tests, have been performed as part of the Central Artery/Tunnel Project in Boston, Massachusetts. The tests, performed on both precast, prestressed concrete (PPC) piles and steel piles, yielded the following adhesion values: [Soil Type Clay Clay Glacial Till Interbedded Sand and Clay Interbedded Sand and Clay Pile Type PPC Steel Steel Steel PPC Adhesion (psf) 610 to 1,200 230 to 900 220 to 550 680 1,280 ] The adhesion appears to be affected by differences in pile material type, with PPC piles having higher adhesion than steel piles. However, part of the apparent difference for the clay may be due to differences in time between driving and testing. The significant range of test data means that the need for site specific testing to determine or verify design values of adhesion should be considered during design. Creep rates at loads near failure ranged from about 0.02 to 0.18 inches per log cycle of time, with most values in the range of about 0.04 to 0.08 inches per log cycle of time.

Jan 1, 1994

By J. Hurdley, J. A. Plant, H. Robotham, P. R. Simpson, G. C. Lalor

Paper presented at the 28th International Geological Congress held in Washington DC, July 1989 (International geochemical mapping sessions). The results of orientation studies for a regional geochemical survey of Jamaica and the CARICOM countries of the Caribbean region are described. The survey is designed to provide systematic geochemical information for a wide variety of applications and, especially, to form a basis for agricultural development in the region

Jul 1, 1991

By R. D. Begley

This paper will present detailed design drawings of a flexible single floor residential superstructure proposed for both longwall and room and pillar mining conditions. All efforts were made to provide an immediately available economical alter- native for future home builders on subsidence prone land. Based on this fact, a basement was not included in the design because additional costs and measures would be required to minimize cracking and leakage. A cost comparison with a traditional superstructure demonstrated that this would be a cost effective alternative. The criteria used to determine the design of the residential structure was as follows: 1. The appearance should not be different then a typical three bedroom residence; 2. Only commercially available devices and present architectural and engineering technology should be used to achieve the required "flexibility" of the super- structure; 3. The structure as completed would be capable of resisting a predetermined amount of vertical and horizontal movement; and 4. If the structure was to experience stresses beyond its capabilities, it could be easily removed from the foundation and releveled.

Jan 1, 1986

By S. Ragab

The objective of flotation models is to predict the recovery rate of minerals from a flotation cell. In this paper a CFD?based flotation models is presented. The model uses first order rate equation, and the collision frequency is estimated using Abrahamson [1] model with input from CFD two-phase simulations. Spatial distributions of dissipation rate and air volume fraction (also called void fraction) are determined by the two-phase hydrodynamic simulations. Knowing these parameters throughout the machine is essential in understanding the effectiveness of different components (rotor, stator or disperser, jets) on the flotation efficiency. Not only the average pulp recovery rate can be estimated but also the regions of high/low recovery rate can be identified. The CFD-based flotation model presented here can be used to determine the dependence of recovery rate constant at any locality within the pulp on particle diameter, particle specific gravity, contact angle, and surface tension.

Jan 1, 2012

By Gang Chen

This paper explores the possibility of using short-term time-dependent plate loading tests to estimate the elastic and viscoelastic parameters of the weak floor strata typically associated with coal seams in Illinois. Plate loading tests with incremental loads, similar to incremental creep experiments, were conducted until the floor failure occurred. For each increment, the load was held constant for a period ranging from 1-4 hours until a constant deformation rate was achieved. The deformation-time data were analyzed for viscoelastic parameters of weak floor strata assuming its behavior to be adequately represented by the standard Burgers model. The analysis required development of mathematical equations for the time-dependent deformation of the standard Burgers material under a three- dimensional state of stress. Time-dependent pillar settlement data at one mine were also analyzed for elastic and viscoelastic parameters of the weak floor strata using the developed equations. These parameters were compared with similar parameters estimated from plate loading tests.

Jan 1, 1990

By D. S. Kieffer

Ground characterized by hard boulders embedded in soft matrix represents one of the most challenging conditions for TBMs, as the cutterhead must cope with the non-optimal conditions of cutting hard blocks while simultaneously excavating through soft, soil-like matrix material. Dowden and Robinson (2001) and Hunt and Mazhar (2004) summarize several case histories relating to the problems of advancing a TBM through boulder-laden ground and provide guidance with respect to appropriate site investigations and baselining strategies. Some rock types constituting boulder-laden ground include: ?Sedimentary Rocks?cemented alluvial channel deposits, colluvium/talus, landslide debris, and glacial till. ?Igneous Rocks?agglomerates, lahars, and pyroclastic deposits. ?Metamorphic Rocks?tectonic mélange and cataclastic fault zones. ?Decomposed Rocks?corestone bearing saprolites. Disc cutters are commonly utilized to cut the hardblocks; however, as compared to the understanding of disc cutter behavior in hard continuous rocks, little is known regarding fundamental cutting mechanisms in highly heterogeneous bouldery ground conditions. To advance this understanding, a suite of full scale tests have been performed using a linear cutting machine at the Colorado School of Mines (CSM). This paper summarizes the observed cutting mechanisms and their practical implications for TBM excavations through boulder-laden ground.

Jan 1, 2008

By Arnold M. Lansche

DOMESTIC OUTPUT of white arsenic, As2O3, was derived entirely as a byproduct of smelting arsenic-containing copper ores by The Anaconda Company at Anaconda, Mont., and American Smelting and Refining Company at Tacoma, Wash. Arsenic metal was not produced. Consumption, and Uses.-Most of the white arsenic produced in 1964 was consumed in manufacturing lead and calcium arsenate insecticides. In the 12 year period since 1951 the production of lead arsenate insecticide has varied between 7,800 tons and 4,900 tons, indicating that lead arsenate has maintained its position in competition with organic insecticides.

Jan 1, 1965

By L O. Filippov, Q Dehaine

Variographic analysis, a classical tool from the Theory of Sampling (TOS), can address practical situations with multiple variables; however, its application has very often been limited to one variable at a time. Recent developments have shown the benefits of using multivariate approaches for variographic characterisation of a set of variables instead of considering individual variables sequentially. Among these approaches, the multivariogram has been revealed itself to be a powerful tool when the overall time-variability of a process must be summarised in terms of a large set of properties (variables) to assess its true global variability. However, even when choosing the properties of interest carefully, the resulting global variance obtained with this approach may be very high. In particular, some variables that contribute to a major proportion of the global (multivariate) variability could be less important for the process performance than others having a lower variability. To address this issue, a new approach is proposed, combining the multivariogram with process modelling and multivariate data analysis methods such as partial least squares (PLS) regression from chemometrics. An example from the mineral processing industry is presented, for which the process performance could be linked to key process variables (sensor data) using the PLS regression. Once introduced in the multivariogram equation, PLS model parameters (loading-weights or regression coefficients) can be used to weigh the variables according to their relevance for the process. In addition, this also permits characterisation of process performance variability with time using only the process input variables and a weighted metric according to the PLS regression model. Ultimately, this method helps to find an optimised sampling procedure in terms of frequency, sampling mode and number of increments according to the actual overall process performance. This approach has potentially many applications in the mining, feed and food, pharmaceutical or any other industry for which it can be used to reduce risks and ensure a better use and management of resources.CITATION:Dehaine, Q, Filippov, L O and Glass, H J, 2017. Optimising multivariate variographic analysis with information from multivariate process data modelling (partial least squares regression), in Proceedings Eighth World Conference on Sampling and Blending , pp 381–390 (The Australasian Institute of Mining and Metallurgy: Melbourne).

May 9, 2017

By Alex C. Smith, Thomas A. Gray, Lynn M. Crayne, Michael A. Trevits, Phil Glogowski

Mine fires constitute one of the greatest threats to the health and safety of those working in the underground environment and each event has the potential for disastrous consequences. Of the major mine fires and thermal events that have occurred in the United States in the last 6 years, it is estimated that remotely installed seals could have been used in 63% of the events to control fire growth or to aid in fire suppression work. The National Institute for Occupational Safety and Health (NIOSH) is conducting full-scale tests at the NIOSH Lake Lynn Experimental Mine to evaluate and improve remote mine seal construction technology. The main focus of this work is to develop reliable technology that will completely close the mine opening from floor-to-roof and rib-to-rib. This paper presents the results of remote seal installations using grout-based materials.

By Fred E. Fiedler

A demonstration project investigated the feasibility and effectiveness of two management interventions, Management Training and Organization Development, for improving productivity and safety in metal/non-metal mines. The management training intervention was conducted at Texasgulf Company's trona mine, using three nearby trona mines as controls. The Organization Development intervention took place in Hecla Mining Company's Lucky Friday mine, using the highly similar Star Mine as control. The two management interventions seemed about equally effective in reducing accidents and injuries, as well as MSHA citations, and the management intervention at the Texasgulf mine also appeared to have led to substantial improvement in mine productivity.

Jan 1, 1983

By E Deucker, A White

Gold Fields Australia (Gold Fields) has identified that improving productivity through more detailed shift planning and operational control of mining activities is a key driver to the success of their business. The Hamlet mine was chosen as a pilot site to trial a system that would allow production engineers and shift bosses to align the execution of short-term activities with the longer-term goals of the organisation.Gold Fields partnered with Deswik to introduce an on-site, collaborative, web-based system to allow mine planners to quickly build-up a detailed, activity-based, shift schedule for the coming week from the 13-week plan. Multiple stakeholders could then review and alter the plan, and then track and manage the execution of the activities.The system is designed to be integrated with production data capture systems to allow tracking of progress towards completion for each activity, as well as to plan and monitor the equipment operating in the mine. Integration of systems allowed engineers to use the large quantities of production data being captured to make informed decisions in the operations environment.The system replaced a complex set of spreadsheets that required expert users in Gold Fields to maintain. By capturing the data in a central database, the planning process is transparent and historic data from the execution of activities is available for analysis to improve productivity in the future.The system has ensured that the highest priority and critical path activities for the business are completed at the right time, improving the efficiency of operations.CITATION:Deucker, E and White, A, 2017. Productivity improvement through collaborative shift planning and tracking, in Proceedings 13th AusIMM Underground Operators’ Conference 2017, pp 225–234 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Oct 16, 2017

By R. Patrick

As a unique South African organisation, CSIR: Division of Mining Technology (Miningtek) strives to support the mining industry by improving health, safety and productivity through developing, adapting and transferring technology. Considerable effort is currently directed towards the development of potential non-explosive mining methods with the potential to allow continuous mining in narrow reef conditions. Besides improving productivity, continuous mining results in concentrated mining which has a significant impact on reducing infrastructural costs. Impact Ripping and Water Pulse Rock Breaking have been tried on gold mines, whereas Activation, Mini-Disc? cutting and the Plasma Holemaker are currently being tested on platinum mines. The organisation?s many years of experience in novel rockbreaking, together with its world-wide collaborator network, has placed it in a unique position to assist the mining industry and manufacturers in developing and/or adapting existing technologies for application underground. Currently a range of technologies are being investigated, which have reached different stages of maturity. The main technologies under investigation are; - Impact ripper system - Water pulse rock breaking - Activated undercutting rollers - Mini disc cutters - Electric rock breaking

Oct 1, 2001

By C. Melvin Lepper

The Bureau of Mines has developed an improved earth resistivity field system which employs a novel technique for obtaining null measurements. The instrument is designed to operate reliably in high-noise environments such as those found in the vicinity of operating mines. The system consists of a low-frequency transmitter, a sensitive receiver and an external battery pack, each in its own case to provide protection from the elements. The receiver and transmitter units have self-contained recharge-able batteries to supply power to the circuitry and separate built-in battery chargers that operate on standard 115 Vac power. The system is portable and simple to operate. Measurement accuracy, reliability, and dynamic range are superior to most commercially available equipment even though less time and effort is required to make null readings. Unlike some commercial systems, long integration times are not required to enhance signal-to-noise ratio in areas of high background noise.

Jan 1, 1974

By M. M. Tilman

Etchants containing hexavalent chromium and sulfuric acid are used in a variety of surface-finishing operations. When the resultant spent solutions are discarded, substantial quantities of chromium are lost and pollution prob¬lems are created. To minimize the undesirable environmental effects while improving metal and minerals recycling technology, the Bureau of Mines is con¬ducting research on a method for the economic inplant recycling of these waste etchants. Trivalent chromium, produced when the etchant reacts with a substrate, is oxidized in the anode chamber of a diaphragm cell; other metals, dissolved during the etching operation, are transferred to the catholyte. When waste brass etchants are treated in this manner, all of the trivalent chromium is oxidized and more than 40 percent of the copper and zinc is removed. Similar copper removal and chromium oxidation are achieved with waste printed circuit board etchants and rinse waters from plastic etching operations. The electrical energy needed to regenerate 1 kg sodium dichromate is less than 9 kwhr. Regenerated brass etchants evaluated by two companies equaled or exceeded the performance of fresh etchants.

Jan 1, 1979