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By Walter E. Mingramm

The construction of rescue-apparatus on the principle of furnishing the wearer with air from a tank containing it under high pressure was given up by inventors about 20 years ago. Such an apparatus must supply continuously, for not less than two hours, nearly 50 liters of pure air at atmospheric pressure per minute, or a total of 6,000 liters (210 cu. ft.); and a cylinder containing this amount of air, under 2,000 lb. pressure, would weigh 180 lb. or more. Although apparatus has been recently constructed utilizing liquefied air, no experiments have been made to determine the regularity with which the air is generated, nor has its chemical composition been determined. Moreover, the chief objection to such an apparatus is the difficulty and cost of keeping on hand a large quantity of liquefied air. The system of furnishing the wearer of a breathing-apparatus with air which has given the best results, and has found

Jan 1, 1909

By Robert H. Peters

The objective of the project descibed in this report was to design and field test a model health and safety program at a coal mining company and a gold mining company. The model program was implemented primarily by providing training on loss control, accident investigation, and the operation of mobile equipment; and by providing technical assistance to help solve health and safety problems. Data were obtained from company records on occupational injuries, illnesses, accidents, and "near misses"; and through direct observation of employees performing a large number of randomly selected jobs. At the coal mine, employees were observed five times over a 15-month period. At the gold mine, employees were observed six times over a 16-month period. During the study, the percentage of sampled jobs containing one or more safety deficiencies decreased from 74.3 pct to 36.6 pct at the coal mine and from 86.4 pct to 19.1 pct at the gold mine. Work on this project was performed by Woodward Associates, Inc., under a Bureau of Mines contract.

Jan 1, 1986

By R. E. Vivas, J. A. Villa

"INTRODUCTION Located in the state of Colima, Peña Colorada is one of the largest iron ore operations in Mexico. The project is owned in equal parts by ArcelorMittal and Ternium. Though boasting a production capacity of 4.5 million tons of concentrate per year, Peña Colorada is faced with declining ore grades. In order to respond to this situation, Peña Colorada had to expand production even further. This expansion created various challenges that were overcome by the adoption and application of new technology. Examples of these technological innovations are discussed in detail in this paper and include improvements in geo-modeling, mine planning and mine operations. The successful implementation of these technologies paid for itself many times over, and has led to significant improvements in production and performance, while lowering the operating costs and reducing the variance between planning and execution. PROJECT OVERVIEW Peña Colorada is a mining company which produces about 30% of the iron ore in Mexico. This project generates about 1,200 direct jobs and 3,000 indirect jobs, making a significant contribution to the local economy. Similarly, Peña Colorada invests in its local communities through numerous educational programs, scholarships, university agreements, social development, environmental agreements, etc. Peña Colorada’s operations consist of an open pit mine located in Minatitlán and a pellet plant located in the port city of Manzanillo, as shown in the location map below:TECHNOLOGICAL INNOVATIONS Most mining projects around the world typically follow the logic of “mining the next best ore”. Consequently, head grades tend to decline over the life of the mine. In the case of Peña Colorada, a decline in head grade combined with a decline in iron ore prices forced the operation to adapt to a new business environment and adopt new technologies to face these challenges. However, the first step along this process was to increase the confidence and reliability of the resource model. This task involved additional drillhole campaigns coupled with more detailed modeling techniques. Once the block model was completed, new optimization studies and production schedules were evaluated with new optimization tools that unlocked significant project value in many aspects of the mine plan. Similarly, new geotechnical studies were prepared, which provided new guidelines for pit slope design, and new technology was implemented to monitor ground movement and slope stability. The picture below shows two sectional block model views in MineSight 3D, along with the pit designs and geologic solids"

Jan 1, 2017

By L. E. Djingheuzian

Introduction For many years the immense deposits of bituminous sands of northern Alberta have been attracting the attention of our governments, engineers and .scientists ( 6). Undoubtedly these bituminous sands represent one of the greatest potential resources of liquid fuels in the world. However, their commercial development has been retarded by the complexities of the technological problem and by the economic factors involved in the processing of the sands. The technological problem has been attacked from several angles ( 2, 3, 1, 11), and cold water separation of bitumen is one of them. To the ore dressing engineer, the cold water process is of utmost importance since, by the use of standard ore dressing machinery, it accomplishes most efficiently and economically the separation of bitumen from bituminous sands. The significance of using ore dressing equipment was especially enhanced by the fact that the scientific principles which underlie the design of standard machines were demonstrated in the cold water separation process with an extraordinary clarity. This greatly facilitated the analysing of limitations and advantages of different machines during-the pilot plant investigations and helped to complete the investigations practically in the allotted time.

Jan 1, 1952

By M. Cohen

THERE seems to be a natural urge for the human mind to wonder about the beginning of things. When an explosion occurs, we immediately inquire "what set it off?" If a person contracts a disease, we are likely to ask "how did it happen?" On a much loftier plane, when we reflect about the universe, there is the inevitable question "what, or rather Who, started it all?" In principle, these varied queries have at least one attribute in common: they are attempts, whether earnest or casual, to search out the origin of events in nature. Accordingly, they involve not only scientific, but philosophical and even re1igious matters of deep concern. It is evident that, in a broad sense, the phenomenon of nucleation is enmeshed in this enticing concept of "the beginning", but we must extract the scientific component of the problem for our present purposes. Nucleation, as in the case of phase transformations, is best regarded from the standpoint of kinetics. There are then two main steps, which may come in either order: (a) Experimentally, one attempts to measure the frequency with which transformation centers spring into existence; and (b) theoretically, one seeks a model that will account for this observed birth-rate. Temperature, composition, strain, and prior history are some of the important variables that must be considered both experimentally and theoretically when dealing with nucleation in the solid state. Such interaction of theory and observation is an integral part of science in general, but it is particularly significant in the nucleation problem because the very beginning of a phenomenon invariably occurs on too localized a scale in both space and time to be detected with available techniques. Thus, there is little hope of making direct measurements on the nucleus during its birth or to ascertain the exact nature of the process; one can only infer the details of nucleation from the model whose predicted behavior seems to harmonize best with the measured rate of nucleation and its dependence on known parameters. In the field of solid-state nucleation, both theory and experiment call for much ingenuity, but somehow the conceptual schemes have spawned faster than they can be tested by observation. This is not to say that there are many basically new ideas in modern nucleation theory; rather, as we shall see, it is because the required fine-scale measurements are of immense technical difficulty. Quite likely, some of the nucleation models existent today have survived only because of the latitude permitted by meager data. There is great need to bring theory and experiment into better balance in this important area of physical metallurgy. Although one can

Jan 1, 1959

By J J. Robinson, B N. Noller, D M. Franks, G McIlveen, D R. Mulligan, A T. Soro

Fiji is a developing nation that relies on economic opportunities and recently experienced increased interest in mining and mineral exploration that could potentially benefit the country. In order to understand the lack of, or failure of, past rehabilitation activity, this study applied risk-based approaches to identify the significance of activities or actions applicable to rehabilitation of post-mined land in Fiji. This involved the use of qualitative, semi-quantitative and quantitative risk methodologies, which allow assessment and evaluation of mechanisms of mining administration and practices, as well as rehabilitation methods and approaches that have been applied successfully to post-mined land in other countries with similar environmental and climatic conditions and social and regulatory environments to Fiji. The semi-quantitative risk-based technique followed an earlier approach applied for mine closure by Laurence (2006) and provided a systematic way to assess and evaluate rehabilitation issues that were identified on-site by assessors, who were able to estimate through expert judgement the likelihood and consequences based on conditions, situations observed and circumstances on-site. It demonstrated that experienced professionals could reproducibly score likelihood and consequence of selected items relevant to mine site rehabilitation, despite the wide-ranging issues identified during post mined land rehabilitation. The quantitative risk-based approach was adopted as a method to determine environmental bonds for mining projects using the assessment of consequences and likelihood results from the semi-quantitative approach, then incorporating unit cost of materials or activities for local conditions required to fully rehabilitate each issue at net present value. Application to both an abandoned mine site and a newly opened mine site in Fiji showed that this approach could provide a risk-based estimate for rehabilitation cost and demonstrated potential applicable in the Fijian context.CITATION:Soro, A T, Mulligan, D R, McIlveen, G, Franks, D M, Robinson, J J and Noller, B N, ?2014. Risk-based Rehabilitation Strategies for Post-mined Land in Fiji, in Proceedings Life-of-Mine 2014 , pp 165–180 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Jul 16, 2014

By J Bassan

The mining industry is faced with imperatives to improve worker safety and productivity, adapt to skills shortages, high worker turnover rates, and provide more effective maintenance to new and ever more complicated plant and equipment. While more effective use of data combined with advanced analytics offers opportunities for improvement, providing this information to the worker in the field, in real-time, has proven expensive, cumbersome and ineffective. New capabilities are now emerging which address some of the limitations experienced to date. Augmented reality (AR) provides a means to overlay interactive digital information on top of the physical world. Combining the latest visual display, mobile computing and ‘track and trace’ technologies, AR provides an experience similar to a heads-up display in a fighter jet through small, personnel devices, such as smart phones or wearable glasses. Applying AR would allow a mobile worker to ‘see’ all relevant information for a given task, in the context of their physical environment and at the time they require it. The technologies behind AR are rapidly maturing and becoming available at a price point that is viable for commercial applications. It is anticipated that AR will become ubiquitous at a consumer level within the next five years. The specific challenges faced by the mining industry make it an ideal early adopter of AR technologies. This paper examines a number of use-cases of how AR can be applied to the mining industry and the benefits that can be realised. The paper will identify areas of further work and viable opportunities for immediate adoption within the industry.

Nov 22, 2011

By T. W. Smelser

This Bureau of Mines report presents a review of underground testing, test results, and design guidelines of steel-fiber-reinforced concrete (SFC) mine support (cribbing) developed at the Spokane Research Center. The objective of the work was to verify, in field applications, the performance, economics, and acceptance by the mining industry of the SFC supports and establish design guidelines for their use underground. Results indicate superior performance, favorable economics, and enthusiastic acceptance by the mining industry.

Jan 1, 1983

By D. Vanin

"Conventional single heading track drifting in the hard rock mining industry has not shown any significant improvements in advance rates, despite the advent of modern track jumbos and igh speed muck handling systems .This paper presents Kiena 's experience in using a 7 ft 2 in. diameter larva Mark 6 Tunnel-Boring Machine (TBM) for driving 6000ft of drift.IntroductionKiena Gold Mines is located about 5 miles west of the town of Val d'Or, Quebec, approximately 300 miles north of Montreal. The mine commenced production in October 1981 and has gone through various expansions of ore production with 287 916 metric tonnes in 1982 to reach 453 800 metric tonnes in 1986.Due to the majority of claims being covered by a lake, a grassroots exploration drive of remote areas of the property was required to allow diamond drilling on a yearly basis. High speed sequential excavation methods (SEM) of single heading drifting in the mining industry has not progressed much in the past 20 years despite the advent of electric-hydraulic jumbos, Haggloader and Hagglund type cars. Certain examples of record SEM drifting advances have been performed in the past but only under very specific ground and cost conditions."

Jan 1, 1987

By Jr. Norman

Thermoelectric properties of depleted uranium selenides and tellurides were investigated from room temperature to 700 C. Several depleted uranium monoselenides and monotellurides were doped with selected cationic and anionic materials to determine the effect of impurity additions on the thermoelectric properties. The undoped uranium selenides and tellurides were semimetallic conductors exhibiting low Seebeck coefficients and electrical resistivities. Partial or complete degeneracy was in evidence, indicating a charge carrier energy distribution similar to that in a metal. Doping increased the Seebeck coefficients of the uranium monoselenides and monotellurides; however, the corresponding change in the power factor in the figure of merit was small because of the increase in electrical resistivity.

Jan 1, 1965

By M Svartsjaern, D Saiang and K Mäkitaavola

The Kiirunavaara mine is a large-scale (28 Mt/a) iron ore mine located in northern Sweden. The mine is owned and operated by Luossavaara-Kiirunavaara Aktiebolag (LKAB) using sublevel caving (SLC). The SLC area underlies an open pit decommissioned in the 1950s, the current main SLC haulage level is situated at an depth of 1100 m. The main orebody dips 60 degrees to the east with a distinct boundary defining the hanging wall to the east and footwall to the west. Since the 1980s damage has been observed both in the footwall rock mass as well as on the footwall crest of the open pit. Recent investigations indicate that the underground footwall damage is primarily controlled by large-scale slope failure mechanisms. Structurally controlled near-vertical planar shear failures in the upper footwall appear to be driven or facilitated by a step-path like curved shear failure situated in a zone starting ca 250 m, and intersecting the SLC about 100 m above the active mining level. To confirm this failure evolution a pilot underground measuring system has been designed and installed to monitor the expected rock mass displacements indicated by numerical models based on the above mechanisms. The systems consists of 50 m time domain reflectometry (TDR) coaxial cables installed in the footwall both across and away from an estimated damage extent boundary to monitor shear movements along natural joint surfaces. The TDR installation is combined with long extensometers to facilitate differentiation between diffuse shear and rock mass normal expansion. Additionally, a low-tech system of tape extensometer lines are installed in drifts and stopes running perpendicular to the ore strike to monitor horizontal displacements in the infrastructure as the footwall ‘slope’ loses confinement during mining advance when the mined out areas are replaced by caved rock from the hanging wall.CITATION:Svartsjaern, M, Saiang, D and Mäkitaavola, K, 2016. Underground footwall monitoring at the sublevel caving mine – Kiirunavaara, Sweden, in Proceedings Seventh International Conference and Exhibition on Mass Mining (MassMin 2016), pp 773–780 (The Australasian Institute of Mining and Metallurgy: Melbourne).

May 9, 2016

By Will H. Coghill, I. L. Feld, G. D. Coe

The object of this paper . is to make known the superior classification accomplished in a hydraulic classifier designed to make use of principles determined by recent research ... The details of the design , the results of preliminary research , and the final testing are given . The classifier of the new design shown in figure 1 and another one like it are in operation as concentration classifiers in a Birmingham iron- ore mill recovering 4 tons per hour of concentrates from table middling that ` otherwise would require regrinding and retabling . The four factors that contribute to the successful operation of these classifiers are ( 1 ) a teeter column of small diameter , ( 2 ) use of an open - bottom tooter column classifier with a periodic pincer instead of the usual type , which terminates in a vortex, ( 3 ) a sorting chamber under separate hydraulic control , and ( 4 ) a teeter column of more than the usual depth . · At the outset it must be stated positively what the authors mean by hydraulic classification : They mean the reconstruction of a multimineral ground product into fractions graded with respect to size , so that cach fraction has the heavy mineral segregated in the fine sizes and the light mineral segregated in the coarse sizes . This definition presupposes that in multiplespigot classification the low specific gravity minerals are carried beyond the first cells to the later ones . The reader must take into account that , from the standpoint of classification , " ores " may be divided into two types , represented - by the following : ( 1 ) Joplin flint - blende ores , which , because of the hardness of the flint and the softness of the blonde , yield upon comminution a product that already has the essence of classification ; and ( 2 ) Birmingham Big Seam iron oros , which contain " easily shelled - out " sca sand and , upon reduction to about 10 mesh , yield a heterogeneous mixture in which the size analyses of the respective " floats " and " sinks " arc almost identical .

Dec 1, 1945

By Ashraf M. Eid

Most research dealing with the problem of laterally loaded piles has been the response of individual piles subjected to lateral loads and/or bending moments. However, piles are seldom used individually but are normally constructed in clusters or groups. Little information is available of the effect of pile-soil-pile interaction (PSPI) on the performance of the group. This may be attributed to the difficulty of carrying out full-scale tests. Such tests are prohibitively expensive and require special installations to provide the required large lateral loads. The problem of laterally loaded single piles or pile groups involves the complexity of extending the theoretical solutions to the limits where the actual soil behaves nonlinearly. As the load increases, the elastic soil behavior cannot be adopted for design. Nonlinear soil behavior or the elasto-plastic behavior is evident. This research consists of experimental and theoretical models. The experimental work was conducted on models of free head pile groups in different configurations. The piles were in a sand formation and compared to the behavior of a single pile. The possible factors that influence the group behavior could be visualized. The experimental data was also compared to the widely used theoretical approaches to determine their adequacy. The analytical model makes use of the finite difference approach to calculate the soil non-linearity. A new approach equates the measured ground deflection and maximum bending moments of each row at every load level with the analytical model of single pile. This is the Deflection-Moment Fitting (DMF). The most suitable non-linear soil modulus modes and row contributions could thus be determined. Design of pile groups can be based on data pertaining to soil characteristics of the single pile. Results of the analysis were consistent with other approaches and proved to be adequate for design.

Jan 1, 2005

By B. G. Klugh

(New York Meeting, February, 1912). IN a paper before the Institute at Wilkes-Barre, Pa., June 1911,1 Mr. James Gayley discussed the application of this process to iron-bearing materials. The same author2 described the results of operations at the plant at Birdsboro, Pa. The purpose of the present paper is to present further discussion of some technical details involved in the operation of this plant, and of the theoretical and practical relations of this product to blast-furnace practice. Since Oct. 1, 1911, the Birdsboro plant has been in operation at the blast-furnace of the E. & G. Brooke Iron Co. The results have been highly satisfactory, although the material treated, being chiefly the flue-dust currently made by the furnace or taken from the accumulated stock-pile, was excessively high, and yet not uniform, in carbon, so that the desirable control or regularity of the amount of fuel in the mixture treated could not be maintained. Nothing could more forcibly demonstrate the flexibility of the process than the fact that, under these conditions, the sinter produced was, in all cases, of excellent quality. The Dwight & Lloyd process, as such, and its present highly-developed mechanical appliances were described by Mr. Gayley in the paper above mentioned. While the repetition of some particulars will be unavoidable in this paper, it will be confined to features bearing upon the metallurgical principles involved. According to the principle of the process, the finely-divided iron-bearing material to be sintered is intimately mixed with

May 1, 1912

By E. Ghali, W. Zhang, G. Gabra, N. Sorour, G. Houlachi

The additives polyacrylamide, 1-Butyl-3-methylimidazolium chloride, Tetra-butylammonium bromide, Benzalkonium chloride and chitin are evaluated during zinc electrolysis from synthetic acidic sulphate electrolyte containing Mn2+ ions, in absence and in presence of 0.0055 mg dm-3 of Sb3+ ions. Galvanostatic polarization tests for 2 hours at 50 mA cm-2 and 38oC were carried out to determine the cathodic and anodic potentials, and current efficiency of the deposited zinc. Potentiodynamic polarization and cyclic voltammetry tests have also been employed to study the electrochemical behavior of each additive on the zinc deposit on aluminum electrode. Results showed that, in presence of Sb3+, adding 1 to 3 mg of 1-Butyl-3-methylimidazolium chloride increases the cell voltage by ˜0-7 mV. Current efficiency is increased by ˜4.90-6.40%; power consumption is reduced by ˜147-173 kWh t-1 by adding 1-3 mg, respectively. However, in absence of Sb3+, cell voltage is decreased by ˜7-28 mV, current efficiency is increased by ˜0.70-1.50%; power consumption is reduced by ˜41-47 kWh t-1 by adding 1-3 mg. The effect of the other additives on cell voltage, current efficiency, lead content and morphology of zinc deposit has also been examined. Surface morphology and crystallographic orientation of the deposit was studied using scanning electron microscopic (SEM) and X-ray diffraction (XRD), respectively. The content of lead in the deposit has also been measured using inductively coupled plasma spectroscopy (ICP).

Jan 1, 2015

Newcrest Mining Limited (NML) owns and manages the Ridgeway Gold Mine (RGM) located outside Orange in the state of New South Wales. RGM is a new underground sublevel caving (SLC) operation that is ramping up production to 4 Mtpa. The success of the SLC method at RGM is strongly influenced by production drill and blast practices. Distinguishing features of the Ridgeway SLC operation include choke blasting against broken rock, drawpoint brow preservation, loading of blastholes with different in-hole bulk emulsion densities, precharging of production rings and routine drawpoint fragmentation assessment. These areas are described in the context of RGMÆs required blasting objectives, production drilling and charging activities and innovative practices.

Jan 1, 2002

By D. W. Mitchell

This Bureau of Mines report summarizes experience and past research on methods for sealing abandoned areas of a coal mine and areas from which the pillars have been wholly or partially extracted. The Federal Coal Mine Health and Safety Act of 1969 requires that such areas be ventilated or sealed with explosion-proof bulkheads, but the present study indicates that bulkheads alone cannot isolate areas in a coal mine in which methane and other dangerous gases have accumulated. Gas-air exchanges between sealed and open areas must be controlled.

Jan 1, 1971

By John W. Buch

Hydraulic cutting tests made on samples of Pennsylvania anthracite (3,700 psi and 260 gpm) were promising enough for the Bureau to establish a full scale experiment in an anthracite mine. Water pressure and quantity for mining anthracite were arbitrarily established at 5,000 psi and 300 gpm (1,000 hp). For full-volume flow, hydraulic pressure is controlled by orifice size with the displacement pump. The hydraulic jumbo was designed for maneuvering on pitches from 0° to 20° in any direction and for a coalbed ranging in thickness from 10 feet 6 inches to 15 feet. All motions of the jumbo are by oil hydraulics. Jet flow is controlled (start-stop) at the face, through an interlocked pushbutton system. One button is in the operator's cab; one, at the pump station; and one (a safety shutoff), near the mining face. To December 1962, 7,400 tons of bed material had been mined at an average rate of 0.800 ton per minute, with an average power requirement of 14.125 kilowatt-hours per ton. In January 1963, the objective was changed from an engineering-development basis to a research basis--to determine, ultimately, the most efficient level of operating characteristics for maximum response, as measured by mining-out rate. This research phase of the project is not yet complete, but conclusions, and the method of arriving at them, will be made the subject of another Bureau publication. It should be noted that as of December 1963 nearly 13,000 tons of bed material had been mined, at rates as high as 1. 3 tons per minute for a complete face advance.

Jan 1, 1965

By G. A. Kordosky

Solution mining followed by solvent extraction-electrowinning (SX-EW) is one possible way to economically extract copper from ore bodies which cannot otherwise be profitably exploited. Published costs for the unit processes of SX and EW are out of date especially in view of the newer reagents now available and the newer circuit configurations, This paper updates the costs for SX-EW in 1985 dollars and also discusses some of the trade-offs which must be made when designing an SX-W plant.

Jan 1, 1986

By C. E. Jordan

The U.S. Bureau of Mines investigated flotation hydrodynamics to improve the recovery of coarse phosphate. Fluid velocity profile measurements were used to characterize the hydrodynamics within commercial phosphate flotation cells and laboratory flotation cells. The effects of agitation, aeration, and pH on coarse phosphate recovery were measured in the laboratory flotation cells and correlated with the hydrodynamics measurements. Test results revealed that the agitation energy and aeration level had a significant effect upon flotation response. By optimizing these two parameters, 92 pct of the phosphate was recovered in a rougher flotation concentrate grading 28 pct P2O5?

Jan 1, 1994