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By N. E. Hanna

An investigation was made of pressure pulses produced by unconfined explosive blasts in underground openings. Four tests were made with TNT or modified amatol charges ranging in weight from 60 to 2,000 pounds; each test involved either single or multiple charges. Pressure-time profiles were obtained using mechanical self-recording pressure gages. The cube-root scaling law for peak pressure was found to be valid within about 1 tunnel diameter; at greater distances, the pressures obtained along direct paths were generally higher than this scaling law would indicate.

Jan 1, 1968

By Julie Shang, Tim Evans, Michael McDonald, Yu Guo, Bingfeng Xue

Effective chemical grouting represents a technical and economic solution to many challenges related to soil stabilization and blocking the flow of water. Chemical grouts are facing increasing demands in durability, environmental impact and value. To better meet these challenges, a novel and cost effective process was developed to produce a sodium silicate that increases the ratio (i.e. silica to alkali) beyond what has been used in traditional silicate-based grouts. The move to a lower sodium form of silicate was anticipated to have two desirable performance enhancements; a reduction in leachable sodium and improvement in the durability of the silicate grout. An in-depth study was performed at the University of Western Ontario Geotechnical Research Centre to quantify improvement in durability as well as other performance properties such as compressive strength. The study began by first modelling the gelation time and reaction kinetics of the high ratio sodium silicate over a range of silicate concentrations using two different setting agents as well as with/without a hardener. As expected, reducing the level of sodium produced a much more water resistant grout. These same formulations also showed a four order magnitude reduction in permeability. Somewhat surprising, test results showed the higher ratio silicate having much higher compressive strength. At the time of this abstract, the high ratio silicate was moving to the trial stage for geotechnical applications while the petroleum industry was further along with several successful field trials for water blocking as well as cement remediation. This paper will review the chemistry, testing and features of this next generation form of sodium silicate. Introduction Sodium silicate based grouts have been used for decades for soil stabilization and water control. Over the years, several silicate-based systems have been tailored for specific application conditions to maximize performance and reduce cost. Past research has also focused on the selection of setting agents and hardeners for silicate grouts. A constant in the development effort has been the grade of sodium silicate. The vast majority of chemical grouts have been formulated using a ~3.2 ratio sodium silicate. As a very brief overview on the meaning of “ratio” and why it is so important to performance properties. The ratio describes the proportion of sand to alkali or SiO2:Na2O used to make different grades of sodium silicate. Comparing a 2.2 ratio to a 3.2 ratio, it is easier to polymerize and set the 3.2 ratio. Upon setting and forming a silica gel, the system has higher compressive strength values and improved durability with a reduced level of syneresis (i.e. shrinkage). This leads to the question if 3.2 is better than 2.2 why not go to 4.2 or higher?

Jan 1, 2018

By D A-F Batchelor

"An EXTENDED ABSTRACT is available for download. A full-length paper was not prepared for this presentation.South-East Asia represents the world’s most productive tin province, mainly from placers. Kalimantan has been a major diamond producer, while in the 1980s a placer gold rush occurred in Indonesia and Malaysia. Reviewing extensive geological and mining data highlights phenomenal palaeo-environmental changes in the Sundaland region, interpreted to be responsible for generating ‘giant’ placers. Correlation of the Late Cainozoic stratigraphy has been facilitated from mine exposures and drill holes distributed throughout Peninsular Malaysia, the Indonesian Tin islands and Kalimantan, including contiguous marine areas with extensive shallow seismic profiling data. Knowing the association of rich placers with palaeo-environmental episodes and stratigraphical units has been helpful to facilitate their discovery. All three placer commodities responded similarly to region-wide landscape evolution following Mio-Pliocene high sea levels. Commencing with major regression, important stages comprised: a long period of landscape stability with deep weathering during the maximum Sundaland extent gradually rising sea levels/precipitation initiated slumping of mineralised regolith to form fans, later reworked by braided streams with aggradation (Old Alluvium); during episodic pluvial periods downcutting upgraded placers significant change occurred around Middle Pleistocene time with peneplanation and pedogenesis from Late Pleistocene time ‘modern’ fluviatile deposition (Young Alluvium) filled incised V-shaped valleys.Placer seams show systematic variation in stratigraphic position, in particular cassiterite especially occurs in the Old Alluvium (equivalent Upper Dahor Formation in Kalimantan). Gold is commonly richer in gravelly younger deposits, partly because of secondary precipitation within permeable alluvium. Reworked diamonds are predominantly concentrated especially in younger fluviatile alluvium.CITATION:Batchelor, D A-F, 2015. Conceptual exploration for tin, gold and diamond placer deposits in ‘Sundaland’ (Indonesia and Malaysia) by understanding the late Cainozoic stratigraphic context, in Proceedings PACRIM 2015 Congress, pp 499–506 (The Australasian Institute of Mining and Metallurgy: Melbourne)."

Mar 18, 2015

By Jacqueline V. Rich

The relationship between surface and ground water quality and copper mining in the Globe-Miami area is investigated in this three-year study. Methods to prevent, minimize, mitigate, or treat polluted waters are identified and evaluated. Best Management Practices are incorporated in a recommended plan to manage the area's water quality.

Jan 1, 1983

By Kurt Oakes, Paul Worsey, Braden Lusk, Tony Brasier, Scott Crabtree, Randy Wheeler

Theoretical description of destructive wave interference and the use of sacrifi cial holes is included and is supported by data collected at Springfi eld Underground. Finally, the process by which the reduction in vibration was achieved in practice is described. Results are discussed for several production blasts taking place over a one year period.

Jan 1, 2008

By Michael D. Justason

...a global perspective... In March of 2000, the Japanese Geotechnical Society added "Rapid Load Testing" to their national standard for pile testing. In the year 2000. it is estimated that there will be more than 500 "Rapid Load Tests" on foundations around the world. ...so what is a "Rapid Load Test", and why is it gaining acceptance and popularity?

Jan 1, 2001

By Gustavo E. Armijo

This job was done in Morristown, NJ, with mono fluid system jet grouting for the construction of a new bank building. After the demolition of the existing two story structures, an excavation in loose sandy fill materials was necessary in order to reach the new structure basement level. Due to this jet grouting was selected as a medium to provide both excavation support and permanent underpinning, minimizing the adjacent building settlements. These two adjacent buildings were partially underpinned with a "gravity wall" made with 2 and 3 rows of secant vertical and inclined jet grout columns. Besides the classical jet grouting control methods, during the jet grouting execution, all the drilling and grouting parameters were recorded by a proprietary system called "Slogger". Additionally, after the jet grouting execution, an innovative result control technique was used by means of the application of the same parameter recording system. Some of the production columns were re-drilled and a comparison was made between the obtained drilling parameters and those obtained for the same age test columns. Under the referred existing conditions and in comparison with the conventional underpinning techniques, this project demonstrated that jet grouting, with proper execution and result control, can be faster than them and can maintain the building structural stability and act, at the same time, as a retention system minimizing the existing building settlements.

Jan 1, 2002

It is a pleasure and a privilege to be with you for the Annual Conference of The Australasian Institute of Mining and Metallurgy.The inaugural meeting of The Institute was held in Adelaide in April, 1893. Through the kindness of your President, who passed on to me several publications concerning The Institutute I have been able to glance back over the eighty years in which The Institute has served both the profession and Australia.In that record, many names of great distinction caught my eyes. When one reads the list of past presidents of the The Institute since 1893 and the list of those to whom The Institute Medal has been awarded, one reads the headings of a biographical dictionary of the Australian mineral industries. Many famous names are there-men from the great mining companies, engineers, scientists, metallurgists and geologists. Simply to read the names is to recall great enterprise and great achievement. Going over those names one hears the echoes of the inspiring story of the establishment of the Australian steel industry, the electrolytic zinc inq.ustry, all the major developments in the mining of coal, gold, copper, silver and lead, the treatment of difficult ores, the geological exploration of a cqntinent, the discovery of uranium, bauxite, petroleum, nickel, the establishment of the alumina industry and finally the mammoth earthmoving operations of today. The list of names is a chronicle of great men who did a mighty work. They stand like milestones in the progress of a nation.When one reads further and runs down the titles of some of the papers published in the Proceedings of The Institute even a layman like myself can appreciate the dramatic developments in mining and metallurgy that have transformed the whole practice of the mineral industries in our land. Australians have made some notable innovations and discoveries both in mining techniques and in the processing of ores. The history of mining is not only a story of the discovery of the mineral resources of this continent but of adventurous steps taken to perfect new ways of mining the ore and extracting the metal.I read with great admiration the presidential address given by Sir Maurice Mawby in 1968 and wa...

Jan 1, 1973

By Madgwick J. C

Four manganese dioxide leaching microorganisms, an Achromobacter spp, Aspergillus niger, Elllerobacter cloacae and Elllerobacter agglomerails were purified from sucrose enriched crude mixed cultures which contained at least sixteen, non-leaching, morphologically different, colony types. Fastest leaching rates were obtained from the original enrichment's mixed cultures (1.26 g Mn++ I/d) while best yields of Mn++ m terms of sugar use came from Achromobacter and A. niger being 0.84 and 0.89 g Mn++/g sucrose respectively. The peak efficiency in manganese reduced, per carbohydrate used, coincided with the exponential growth phase for Achromobacter. The two Elllerobacter species performed better in stationary or senescent growth phases.

Jan 1, 1985

The selective placement of coal strip mine overburden is examined. Physical end chemical properties of spoil detrimental to revegetation and groundwater are detailed. The United States is divided into regions of similar problems. Five mining methods already used in the industry, that are capable of selectively handling; waste are examined in detail. Technical and economic comparisons are made for the systems when applied to realistic mine settings. The same analysis is conducted for five novel methods capable of selectively handling waste. Comparisons arc made between novel and existing methods. Suggestions for new and modified equipment are outlined. Recommendations for further research are provided.

Jan 1, 1981

By Charles G. Howard

Accidents involving underground rail transport were analyzed to quantify the magnitude and the operational requirements for individual mine car braking systems. The results showed that the brake preventable accidents represent only 2% of the total underground fatal accidents and less than 1% of the total underground nonfatal accidents. In addition, the brake preventable accidents are expected to decline over the next decade. The costs of accidents involving deaths and Injuries were determined using various well accepted methods. The costs of a brake retrofit program for all operating underground coal cars were developed separately for small and large coal mines. Costs of retrofit brakes, new car brakes, maintenance, inspection and repair facilities were included in the esimates. The analysis showed that a retrofit program would not significantly increase safety, and that the program cost would greatly exceed the corresponding expected benefits.

Jan 1, 1979

By H. H. Schrenk, W. P. Yant, F. A. Patty

"INTRODUCTION In accordance with the outline of investigation described in a previous report 5 of the Bureau of Mines dealing with the use of acrolein for detecting leakage of methyl chloride from unit--type refrigerating systems, the work has been extended to include an investigation of its use in a multiple system, This report gives the results of analysis of samples of the gas from representative units of a multiple system charged with methyl chloride containing approximately 0.9 per cent acrolein by volume, The results furnish a basis for estimating the Warning that would be given in event of leakage. The properties and warning intensity of acrolein have been described in a previous report. 5 ACKNOWLEDGMENTSThis investigation was made at the combined request-of Several Inc., Manufacturers of refrigerating, appliances, and the Roeasler Hasslacher Chemical Co., manufacturers of methyl chloride. Acknowledgment is given to R. M. Major, ,chief chemist of the former firm for arranging the experimental site and equipment; to Arthur O. Haseeneall, owner of the apartment building where the investigation was conducted, for his courtesy in permitting the investigation; and to R. R. Sayers, chief surgeon, Bureau of Mines, and surgeon., U. S. Public Health Service, for suggestions and advice."

Sep 1, 1930

By Murray Pearson, Jack Murray

"The danger of autoclaves lies in the high temperatures and pressures that exist in autoclave vessels. The usage of autoclaves will continue to expand in the mining industry because of their efficiency and environmental friendliness. But increasing attention must be paid to ensuring their safety. Safety Instrumented Systems (SISs) play a critical role in autoclave plants by detecting potentially dangerous conditions, taking the plant to a safe state, informing the operator about the plant status and the cause of the trip and expediting safe plant restart. The SIS should ideally be fully integrated with but functionally independent of the Basic Process Control System (BPCS) and provide redundant logic solvers to increase safety and plant availability while reducing spurious trips.INTRODUCTIONWikipedia defines an autoclave as follows: “An autoclave is a pressurized device invented by Charles Chamberland in 1879 designed to heat aqueous solutions above their boiling point to process materials.” A typical autoclave system used in the metallurgical industry includes, besides the autoclave vessel, heat recovery (heater) vessels, high pressure positive displacement (HPPD) feed pumps, vessel lining systems, specialized internals and components, agitators, pressure letdown or flash vessels, isolation and control valves, over 2,000 I/O points and related instrumentation, and emergency relief systems."

Jan 1, 2009

By H. Warlimont

In recent investigations of the microstructure and crystallographic features of martensite by electgon microscopy,', '9 thin films (about 50 to l000A in thickness) have been used as specimens. It was found by W. Pitschl ,2 that the lattice relationships between the supefiaturated fcc matrix and the martensite formed in thin films were different from those observed after transformation in bulk material. Corresponding differences are to be expected in nucleation and in reaction kinetics in the formation of martensite in thin films, but have not yet been reported. In the course of the preparation of thin films of iron-base alloys for investigation by electron microscopy it was observed that films of alloys, whose martensite formation temperature (Ms) was below room temperature, formed martensite during the electrochemical thinning process conducted at or above room temperature. The chemical compositions and approximate bulkM,-temperatures of the three materials on which this observation was made are listed in Table I. The alloys were vacuum-melted from high-purity metals. It can be seen that the effect occurred in alloys that contain only sub-stitutional components as well as in alloys that contain carbon as an interstitial solute. The appearance of martensite formed in this manner is illustrated in Fig. 1, which represents a polished film of alloy No. 1 at XI0 magnification. The martensite plates can be recognized by their surface relief effects. In addition, heavily strained (owrinkledo) austenite can be seen near the edges of the film where it is thinnest and transformation stresses or strains can be accommodated by plastic deformation most easily. The nonuniform distribution of transformed regions is probably due to the varying thickness of the film. These observations were common to all materials listed in Table I. Because effects of supercooling or straining can

Jan 1, 1962

By H. R. Batchelder

Much information on oxygen production and the manufacture of synthetic liquid fuels has been published during the past several years. From time to tine the investment and operating cost of oxygen plants of various sizes has been estimated. Surveys have been made so that the various processes by which oxygen is produced commercially might be compared. The gas-making processes in which oxygen is employed, which wore used in Germany during the war, have been described in T.O.M. reels, and this information has been published. Descriptions of pilot-scale or proposed commercial plants for the production of synthesis gas or hydrogen and their conversion to synthetic liquid fuels also have been published. In general, each of these publications has dealt with a particular phase of the over-all problem. The present paper will discuss the relationship between these phases: The factors that affect oxygen manufacture and costs, the methods for the use of oxygen and for the production of synthetic liquid fuels, and, to some extent, the economic factors that must be considered.

Jan 1, 1951

By H Bibby

Initial analysis of Long Offset Time Domain Electromagnetic (LOTEM) data has traditionally been made in terms of early and late time apparent resistivities. By using more than one grounded bipole as a source, a tensor analysis technique analogous to the method used to analyse DC resistivity multiple-source bipole-dipole surveying may be formulated. We define the æinstantaneous apparent resistivity tensorÆ as the tensor that relates the total electric field vectors at each instant to the steady state (DC) uniform half space current density vectors due to each source. Instantaneous apparent resistivity tensors calculated for a 3D resistivity model suggest that profiles of LOTEM measurements across simple 3D structures can be used to create an image that reproduces the main features of the subsurface resistivity. Where measurements are distributed over an area, maps of the tensor invariants or the tensor ellipses at different times can be made into a sequence of images which provide a way of ætime slicingÆ down through the target structure.

Jan 1, 1996

By C T. Hollick

Conventional processing of heavy mineral deposits containing radioactive rare earth minerals such as monazite and xenotime may cause industrial hygiene problems through atmospheric dust and contamination of product concentrates. An alternative procedure has been developed in which such minerals are removed from bulk heavy mineral concentrates by flotation with little loss of other economic minerals. With fine ores, recoveries of over 95 per cent have been achieved and with coarse ores over 80 per cent, in both cases at high grade. Several flotation regimes have proven effective. The potential for generation of radioactive dust or product contamination is subsequent processing is correspondingly reduced.

Jan 1, 1990

By O. Schumacher

Guidelines for publication of information defining the amount and grade of resource material available in a deposit are well established in Australasia?s JORC Guidelines, Canada?s National Instrument 43-101 and similar documents in South Africa, Peru, Chile and elsewhere (Table 1). These guidelines provide standards to apply regarding the geologic and geostatistical basis for describing the level of confidence to be assumed for an estimate of the amount and grade of material. All of them provide for a strict distinction between material that has been demonstrated to be economically mineable and that which has not, and all of them provide terms such as ?resource? or ?exploration information? to be applied to data regarding material that has not been demonstrated to be economically mineable. It is not until an economic study has been completed that we are allowed to apply the powerful terms ?reserves? and ?ore? to our deposit material. Indeed, the application of these eye-catching labels immediately tells the reader that an economic study has been completed by a qualified person, and that the results of the study were positive. While extensive guidelines are established for describing the level of confidence in published geologic data, and the nature of the economic study that should be accomplished before using the terms ?reserves? or ?ore?, surprisingly little guidance is provided regarding the process to use, and the level of detail to attain, for estimating capital and operating costs for the study. The intent of this paper is to lay the groundwork for development of suitable guidelines for the cost estimating process. While the codes do not provide specific instructions for the cost estimate, they do provide numerous hints and clues to help determine the level of detail expected and the type of procedure to apply in preparing the estimate. This paper will first review the various codes to gain an insight into the thinking of the drafters of the codes regarding their unstated expectations for the cost estimating process. Based on this review, a series of guidelines are proposed for this purpose.

Feb 27, 2013

By John A. Johnson

For the purpose of comparing the amounts of dust produced by various mining operations, samples of atmospheric dust were collected during a complete cycle of drilling, blasting and mucking at or near the face of the Bureau's Mount Weather testing adit while the efficiency of several types of stemming in metal-mine blasting was being investigated. ACKNOWLEDGMENTS All gas samples were analyzed in the laboratory of the Bureau of Mines Gas Section at Pittsburgh, Pa.

Jan 1, 1939

Measurements from an old survey are being machine processed as a pilot project in the development of a computer-assisted method of structural mapping in shield areas. The key element in the system is a field data sheet which requires the geologist to determine a textural hierarchy in each exposure. The pilot system is limited to orientation analysis and utilizes a prior textural analysis, but this would not usually be a problem in utilizing the system ab initio for exploration. A data processing system of this general type offers promise of considerably increased productivity of field geologists by reducing compilation time and improved technical supervision through centralization of processing, and would make structural analysis an economically viable tool in mining exploration and development.

Jan 1, 1969