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By Oliver Bowles

GLASS razor blades, glass chairs, and marble window panes attest that creative genius was still active in 1935. Many less striking, though doubtless more important, developments are to be recorded for the nonmetallic mineral industries, and not the least of them is the establishment of an Industrial Minerals Division in the A.I.M.E. under the able leadership of Samuel H. Dolbear, Chairman. Thus the nonmetallics are rightly granted equal dignity with metals and fuels in the category of mineral industries. The brief review of progress that follows merely touches the fringe of important developments in this broad field.

Jan 1, 1936

"Requests are frequently received by the Information Service of the Bureau of Mines for published information on the coals of different foreign countries, as compared with coals mined in the United States. The analyses of various coals from several countries on the Pacific, which were submitted to the Fuels Division for certain tests between the years 1913 and 1916, may be of interest, and are shown below: Results of Analyses of Various Coals from China, New Zealand, Japan and Australia."

Sep 1, 1925

By Y. Sagawa

The Hishikari Gold Mine consists of epithermal vein type Au-Ag deposits, each of which has several veins standing almost in parallel each other and inclining 70 to 90 degrees. The veins have 1 to 3m widths and are extracted mainly by drifting and bench stoping with waste rock fill. The Hishikari has tried to optimise the stope dimensions by the Potvin’s Stability Graph Method, which is well known as an easy and effective tool to design appropriate stope dimensions. The method, however, has some limitations of application due to its simplicity so that it has been used only in limited cases. The authors developed a new numerical approach, based on 2D FEM solu-tion for the stability analysis. As a result, it has been possible to solve the Hishikari situation. The authors also introduce the concept of the design approach and compare the results obtained by us-ing the approach with the database of the Stability Graph Method for validation. La mine d’or Hishikari se compose de gisements d'Au-AG avec des types de filons épither-maux dont chacun a plusieurs veines qui sont presque parallèle les unes par rapport aux autres et sont inclinées de 70 à 90 degrés. Les veines ont de 1 à 3 m de largueur et elles sont principalement extraites en creusant et en abattant des bancs de roches encaissantes. Hishikari a essayé d’optimiser les dimensions du chantier d’exploitation avec la méthode de graphique de stabilité de Potvin, bien connue comme un outil facile et efficace pour avoir des dimensions de chantier d’exploitation appropriées. Toutefois, la méthode a certaines limites d’application dues à sa sim-plicité de sorte qu’elle a été utilisée seulement dans des cas limités. Les auteurs ont développé une nouvelle approche numérique, basée sur la solution 2D FEM, pour l’analyse de stabilité. Par conséquent, il a été possible d'expliquer la situation de Hishikari. Les auteurs présentent le concept de l'approche et ils comparent les résultats donnés en l'employant avec la base de données de la méthode de graphique de stabilité pour la validation. Die Hishikari-Goldmine besteht aus Au-Ag-Ablagerungen mit epithermalen Adern, die jeweils mehrere Adern aufweisen, die mit einer Neigung zwischen 70 und 90 Grad nahezu parallel zueinander verlaufen. Die Adern haben eine Breite von 1 bis 3 Metern und werden überwiegend durch Vortrieb von Stollen und Bergversatz abgebaut. Hishikari hat versucht, die Abmessungen des Abbauorts durch das Potvins Stabilitätskurvenverfahren zu optimieren, das als einfaches und effizientes Mittel für die Erzielung angemessener Abmessungen des Abbauorts bekannt ist. Das Verfahren weist jedoch aufgrund seiner Einfachheit einige Anwendungsbeschränkungen auf, so dass es nur in einigen Fällen benutzt worden ist. Vor diesem Hintergrund haben die Autoren einen neuen numerischen Ansatz entwickelt, der hinsichtlich der Stabilitätsanalyse auf der 2D-FEM-Lösung beruht. Dadurch wurde es möglich, das Problem von Hishikari zu lösen. In diesem Dokument stellen die Autoren die Grundlagen des Ansatzes vor und vergleichen die erzielten Resultate durch Benutzung der Datenbank des Stabilitätskurvenverfahrens zur Validierung.

Jan 1, 2003

By Barry D. Lichter, Pierre Sommelet

High-temperature heat contents of InAs and GaAs were measured over the temperature range 400°K to temperatures above the melting points using a di-phenyl ether drop calorimeter. Smoothed values of the thermal properties have been derived and tabulated at even temperature interuals . The heats of fusion of InAs and GaAs were determined as, respectively, 8790 ± 200 and 12,590 ± 300 cal per g-atom at the respective melting points of 1210º ± and 1513º ± 1°K, yielding entropies of fusion of 7.26 * 0.16 and 8.32 ± 0.20 cal perºK per g-atom, respectively. A general discussion of the thermal properties of III-V com-pounds is given. THE low-temperature heat capacities of InAs and GaAs have been determined by Piesbergen.1Using a dynamic temperature modulation technique, Miller2 has determined the heat capacities of the compounds as well as GaSb and Ge between room temperature and 650°K; however, it has been observed that values determined by drop calorimetry for GaSb3 and for germanium4 are consistently about 5 pct lower than Miller's results. Cox and Pool10 report values for the heat content of InAs and GaAs and the heat of fusion of InAs. No value for the heat of fusion of GaAs appears to have been previously reported. This paper reports results of high-temperature heat content investigations of InAs and GaAs measured in the range 400" to above 1500°K employing a diphenyl ether drop calorimeter. These results, together with our previous results on III-Sb compounds3 as well as heat-content measurements5 of solid InP and Gap, are used in a general discussion of these compounds. EXPERIMENTAL PROCEDURES High-purity samples of the compounds, stoichio-metric to ±0.1 at. pct, were supplied in the form of crushed crystal fragments by Dr. Carl Thurmond of the Bell Telephone Laboratories. The sample preparation, description of the calorimeter, and details of the heat content measurement have been previously described.3 Samples were sealed in evacuated silica capsules and suspended by a Pt-Rh wire in a Pt-wound vertical tube furnace, heated to temperature

Jan 1, 1970

By M Lentz

This paper will discuss the issues associated with blasting in an urban mining environment that have been addressed by Winstone Aggregates at the Mt Wellington Quarry. These issues include - control of vibration and air overpressure, repeatability of shot performance, fragmentation on an extremely low maximum instantaneous charge, compliance with Territorial Authority regulations and perception. Over the last two years, in order to address these issues, Winstone Aggregates have undertaken a programme of continuous improvement, which has included; ò implementation of new technology; ò revising site procedures; ò conducting an investigation into the structural response of local buildings; ò investigating safe extrapolation; ò extensive public consultation; ò establishing credibility during the consent process; ò identification of perception issues; and ò building relationships and trust with neighbours. The issues addressed at the Mt Wellington Quarry have increasing significance for traditionally rural mining operations, as the input of the local community being urban or rural, increases. New and existing operations have the potential to adopt best practice now, building trust with the community and raising the profile of the industry.  

Jan 1, 1999

By A. Mazzucato

This paper presents the experimental results of driving and load tests on an instrumented pile driven into a test pit filled with fine homogeneous sand.

Jan 1, 2010

By Ping Yang, Tian-bin Li, Min-hui Wu

"The process of filtrate loss of low solid-phase drilling fluid at different content of polyanionic cellulose is investigated by the standard filtration test. The test results showed that when time of filtration is same, the filtrate volume decreases linearly with the increase of content of polyanionic cellulose. When content of polyanionic cellulose is same, the velocity of filter loss decreases nonlinearly with the increase of time and the velocity of filter loss will reach a stable value. The filtrate volume in 7 to 8 minutes can reach half of the total filtrate volume. At the same time, the velocity of filter loss of drilling fluid decreases nonlinearly with the increase of viscosity. When apparent viscosity is between 3.5~4.15 mPa.s, decrease speed of velocity of filter loss is quick. The results are helpful for characteristics evaluation of filtrate loss of drilling fluid and control of filtrate loss.IntroductionDuring the process of drilling, water of drilling fluid can leakage into stratum, the water can result in instability and collapse of borehole wall. At the same time, the original ratio of drilling fluid will change. The density of drilling fluid will increase, the performance of the drilling fluid will change. Controlling amount of filtration is important to drill successfully. The additives of controlling filtrate loss are mainly two types, particle materials and polymer materials. High-molecular polymer is a kind of high-molecular material, has the adsorption effect, high polymer protection, can improve the advantages of slurry viscosity (Xu,2004 and Dehghanpour,2001). Some scholars carried out some study on the polymer material fluid loss agent in recent years, these study mainly focused on CMC, HEC, MHEC, CMHEC, starch and its derivatives(Zhang,2005 and Chevron,2009).About PAC (polyanionic cellulose) as drilling mud additives, a few of scholars carried out some relevant work. Plank (1992) applied PAC into ordinary freshwater drilling fluid and analyzed temperature stability of freshwater drilling fluid. Bennion (2000) applied PAC into drilling fluid and analyzed effect of polyanionic cellulose on strata inhibitory. Huang (2011) analyzed effect of PAC on properties of the high-density water-based drilling fluid. Mahto (2004) applied PAC into fresh water and salt-water drilling fluid and analyzed effect of PAC on rheological properties of the drilling fluid. Wang (2008) applied PAC into alkaline drilling fluid to study various performance of drilling fluid. PAC is a renewable resource and has good application prospect (Ankara, 2005). So it is very important to understand the effect of PAC on filtration process of drilling fluid.The test was conducted by changing the content of the PAC in drilling fluid. The object of this paper is to understand effect of polyanionic cellulose on filtration process of the low solid-phase drilling fluid."

Jan 1, 2017

By Rennie Kaunda, David Streeter, John Kemeny

This paper describes a field/laboratory study that was conducted in cooperation with a mine in Arizona. The primary purpose of the study was to investigate the effect of blasting energy on the crushability and grindability of the post-blast rock fragments. The crushability and grindability of the rock fragments were evaluated through laboratory comminution tests. A secondary purpose of the study was to investigate different laboratory methods for estimating the comminution properties of the rock fragments. In particular, a number of standard rock mechanics tests were conducted and compared with the comminution test results. Finally, the study was used to evaluate new technologies for estimating insitu rock mass strength and for assessing post-blast fragmentation. To estimate in-situ rock mass strength, the specific energy of drilling (SE) was calculated during blast hole drilling utilizing a continuous drill monitoring system. Post-blast fragmentation was estimated using the Split image processing system. Results from the study support the idea that increases in blast energy can enhance crushing and grinding. Also, several simple rock mechanics tests were found to correlate well with the results from standard comminution tests, which could prove to be useful in practice.

Jan 1, 2003

Owing to the increased consumption of sulphuric acid; Australian manufacturers have, from time to time, been seeking for a satisfactory source of sulphur that would make them independent of foreign supplies.Some years ago a considerable amount of acid was obtained from the roasting of Spanish pyrites. This ore, in 1913 or thereabouts, cost 16s. per ton f.o.b. Huelva, and freight to the eastern seaboard of Australia was about 20s. per ton. As the ore contained 48% to 50% of available sulphur, it was costing roughly 9d. or 10d. per unit, and, in addition, the cinder, after roasting, was a product of considerable value to smelters, containing as it did a high percentage of iron suitable for fluxing, and appreciable values in silver and gold.

Jan 1, 1925

"In 2000 the CIM Council approved the CIM Standards on Mineral Resources and Reserves – Definitions and Guidelines, developed by the CIM Standing Committee on Reserve Definitions. The Definition Standards established definitions and guidelines for the reporting of exploration information, mineral resources and mineral reserves in Canada. The Mineral Resource and Mineral Reserve definitions are incorporated, by reference, in National Instrument 43-101, Standards of Disclosure for Mineral Projects, which came into force in Canada in February 2001 and was amended in December 2005.CIM DEFINITION STANDARDS- For Mineral Resources and Mineral ReservesPrepared by the CIM Standing Committee on Reserve DefinitionsAdopted by CIM Council on December 11, 2005FOREWORDCIM Council, on August 20, 2000, approved the ""CIM Standards on Mineral Resources andReserves - Definitions and Guidelines,"" developed by the CIM Standing Committee on ReserveDefinitions. The CIM Definition Standards on Mineral Resources and Reserves (CIM DefinitionStandards) establish definitions and guidelines for the reporting of exploration information,mineral resources and mineral reserves in Canada. The Mineral Resource and Mineral Reservedefinitions were incorporated, by reference, in National Instrument 43-101 - Standards ofDisclosure for Mineral Projects (NI 43-101), which became effective February 1, 2001.At the August 20, 2000 Council meeting a new CIM Standing Committee on ReserveDefinitions was established consisting of the following: John Postle, Bernie Haystead, LarryCochrane, Normand Champigny, Mike Hoffman, Colin McKenny, Jack Mullins, Phil Olson,Fred Payne, Jody Todd and Joe Ringwald.Subsequent to the publishing of the August 20, 2000 CIM Standards on Mineral Resourcesand Reserves, various CIM committees have compiled and published more extensivedocumentation on mining industry standard practices for estimating Mineral Resources andMineral Reserves. These standard practices provide more detailed guidance than that containedin the August 20, 2000 CIM Standards on Mineral Resources and Reserves. On November 14,2004 CIM Council adopted an update to the CIM Definition Standards to reflect the moredetailed guidance available and effect certain editorial changes required to maintain consistencywith current regulations. This version of the CIM Definition Standards includes further editorialchanges required to maintain compatibility with the new version of National Instrument 43-101which is expected to become law at the end of 2005. The CIM Definition Standards can beviewed on the CIM website at www.cim.org."

Jan 1, 2003

By J. A. Cox

The Ashanti mine is located within the Lower Proterozoic Birimian of Ghana, and covers a concession of 474 square kilometres at its Obuasi operations which comprise large scale underground, surface and tailings treatment facilities. The mine had operated for a century at the end of 1997 and had produced nearly 25 million ounces of gold, a significant proportion of which came from the underground operations. This paper covers the strategy under which exploration for both surface and underground mineral resources was instrumental in enabling the expansion programme to go ahead together with the methodologies and results that have developed in the exploration area over the last five years. Within capital expenditure constraints, the objective on surface is to replace oxide depletion with a secondary objective of discovering new sulphides in areas other than the main trend. In the underground, the exploration strategy is directed at replacement of both underground and surface sulphide depletion, minimising finding costs and assisting the development of long lead time infrastructure. The exploration application describes the methodologies in use for both surface and underground exploration that have been developed in recent years in conjunction with a description of a major review conducted in 1995/96 of the exploration database using an integrated approach, geochemistry, geophysics, remote sensing and structural geology. A revisit of soil geochemical data in particular, and modification of exploration methodology led to the success in finding relatively significant new oxides in 1997.

Jan 1, 1999

By M. Hochenhofer

Due to economic aspects and environmental regulations recycling of slag and waste from ferroalloy production became a very important issue for the companies during the last years. The treatment of slag depends prior on the composition, especially on their content of valuable metals and impurities. The final aim should be a total re-use of these materials in the industry e.g. cement industry, pig-iron production etc.. Therefore, to reach the required physical and chemical properties for a further use, possibilities of a metallurgical treatment have been investigated. The conditioning of slag with a high V-, Mo- and P-content via reducing metal bath showed to be one alternative. To determine the optimal process parameters, practical investigations with different slag compositions and thermodynamic calculations were carried out.

Jan 1, 2006

By A. G. Pasamehmetoglu

This paper describes the conver¬gence and load measurements carried out in inclined seams at five longwall faces, two of which were supported by hydraulic props and the other three by conventional timber supports in Karadon-Gelik mine. The minimum support capacities determined in this study are compared with the results obtained from two empirical approaches suggested by Wilson (1975) and Jacobi (1981). The characteristics of hydraulic props to be used and support patterns in the longwalls are found, conclu¬sions are drawn and suggestions are made. Design nomograms are prepared for field engineers, in order to be able to approach the problem more confidently and realistically.

Jan 1, 1992

By Reinhold Schnell, Piers Wendlandt, Nathan Rouse

Drilling and blasting are key components of every hard-rock (i.e.,metal/nonmetal/coal) mining operation. Well-executed and maintained drilling and blasting can have a major positive impact on the overall success of such operations. This case study presents the implementation of a new drill and blast engineer position and systematic improvement of the drill and blast operations at a surface metal mine. The findings of and lessons learned from this case study can be applied toother mine operations to improve safety, production, efficiency, and cost savings. Focus areas for the project included refined communications, operational practices and procedures, planning, designing, and data collection and analysis. This case study showed improved efficiency in communication and planning among the engineers, operations team, and contractor groups over the course of the project. An increased awareness of long-term plans and needs for the drills and blasters reduced or eliminated existing delays. Test blasts that implemented new drill and blast designs and updated operational practices and procedures were tested to streamline the process. Constraints regarding explosive product shipments, geological considerations, and a uniform powder factor provided the basis for new blast designs.

By Bruce W. Gonser, A. U. Seybolt

A few copper-zinc-hasp alloys mppt die-casting requirements reasonably well, although improvements are desired. Aluminum bronzes, high-tin bronzes and some copper-nickel-zinc alloys can be die-cast, according to Herb,' but seldom are because of such factors as higher melting ranges and greater cost than certain of the brasses. Fox2 has summarized the copper-base die-casting alloys that were in commercial use in 1937 and has given the effects of different alloying constituents. Table 1 gives some of the properties of these alloys as reported by Fox. a Properties reported by Fox.2 b Trade name of Brastil, Doehler Die Casting Co., similar to Webert Alloy,34 American Brass Co., and Tombasil Alloy,5 Ajax Metal Co. e Trade name Tinicosil, Titan Metal Manufacturing Co. Melting point (liquidus) of the yellow brass is given by Herb1 as 1650" F., of the high-silicon Brastil (with 4.5 to 5 per cent Si) as 1600" F., and of the nickel silver as 1675" F. d Criterion not stated.

Jan 1, 1940

By A. U. Seybolt, Bruce W. Gonser

A few copper-zinc-hasp alloys mppt die-casting requirements reasonably well, although improvements are desired. Aluminum bronzes, high-tin bronzes and some copper-nickel-zinc alloys can be die-cast, according to Herb,' but seldom are because of such factors as higher melting ranges and greater cost than certain of the brasses. Fox2 has summarized the copper-base die-casting alloys that were in commercial use in 1937 and has given the effects of different alloying constituents. Table 1 gives some of the properties of these alloys as reported by Fox. a Properties reported by Fox.2 b Trade name of Brastil, Doehler Die Casting Co., similar to Webert Alloy,34 American Brass Co., and Tombasil Alloy,5 Ajax Metal Co. e Trade name Tinicosil, Titan Metal Manufacturing Co. Melting point (liquidus) of the yellow brass is given by Herb1 as 1650" F., of the high-silicon Brastil (with 4.5 to 5 per cent Si) as 1600" F., and of the nickel silver as 1675" F. d Criterion not stated.

Jan 1, 1940

By D. A. Paice

Direct current electrical systems are used in most coal mines primarily to power the main haulage trains and secondarily to feed other equipment and passageway lighting. Electrical power is supplied from rotary machines or static rectifier equipment and is distributed through the mine by open trolley wires and feeder cables. The rails of the haulageway are used as a current return path. This exposed power distribution system is very vulnerable to conditions which lead to undesired leakage currents and short circuits and, consequently, the possibility of fires or other hazards to personnel. Present techniques and equipment have been utilized in so far as practical to improve the safety of the dc electrical system; however, there still appears a need for further improvement. Because of this need, this program was sponsored by the Bureau of Mines to investigate two specific technical areas related to improvement of dc electrical system safety. One area included the determination of the characteristics of mine electrical systems and their protection requirements and the verification of the adequacy of available protective devices for mine service. Despite the widespread application of industrial protective equipment in mines, there was little detailed technical information available related specifically to the performance of this equipment in service. Our task was not only to develop useful information regarding mine system protection, but also to define and verify the adequacy of the protective devices available. The second area of investigation called for development of a practical technique for detecting low level electrical fault or leakage currents. Conventional protective devices

Jan 1, 2012

By Z X. Zhang

Ground vibrations from the blasts of the LKAB mine at the Malmberget town had reached 18-19 mm/s from year 2000 to 2002. From 2004 to 2010 the maximum vibrations had been reduced to 9 mm/s and most vibrations lowered to about 5 mm/s, indicating that the technical measures used in the mine are effective in vibration control. The major measure that has always been used in Malmberget mine is the method called Changing Initiation Sequence (CIS in short). Another method named Dividing Ring Blasting (DRB in short) is often applied to some special blast rings in the mine. Both methods have been proved to be successful in vibration reduction, and they do not need any additional costs. Because of the two methods, both maximum vibrations and average ones have been reduced by around 50% since 2004.

Jan 1, 2012

By Justin S. Johnsen

As OEM sensors and interfaces have grown in number, the available data from equipment in the mining environment has continued to multiply. This equates to an increased visibility of operating performance, mechanical and electrical health, and predictive monitoring that can directly improve maintenance reliability and scheduling. With increased visibility, where should a reliability engineer begin to look to directly impact Capacity Assurance? More specifically, what source will provide inputs to the Failure Modes Effects Analysis (FMEA)? Results from these analyses must be documented, and they must contribute to the overall mission of the mining company; these results must reduce costs and increase profits. Through detailed data capturing, documenting, and analysis, Modular Mining Systems? Time Tracking application, used in the MineCare® maintenance management solution, can drive decisions and provide direct impact to engineering projects for continuous improvement in the mine maintenance organization.

Nov 1, 2011

By G. Luttrell

Coal preparation plants play an important role in modern society by providing high quality feeds for coal-fired utilities, industrial boilers and metallurgical coke facilities. Unfortunately, field data indicate that preparation plants are often not operated under optimum conditions, resulting in lower productivity and lost profits. In many cases, this shortcoming can be attributed to a failure by plant operators (i) to recognize the importance of correctly adjusting plant operating conditions to accommodate requirements dictated by coal sales agreements within different coal markets and (ii) to properly account for variations in product moisture with particle size across different plant circuits. This paper discusses the important influence of moisture constraints on preparation plant optimization and provides a case study to illustrate the potential gains that can be realized via proper understanding of plant moisture control.

Jan 1, 2009