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By Stanley Griff, William Herrera, William O. Seals

"The Navy initiated liquid propellant research in the early 1940's. The first promising Navy liquid propellant, Otto Fuel II, was developd in the early 1950 as a potential torpedo fuel. Later, the Navy developed a HAN based liquid propellant designated NOS-365, a hydroxylammonium nitrate, isopropylammonium nitrate and water formulation. A large gas volume generated by this propellant produced a large wake behind the torpedo. As one can readily understand, this negated the useof the propellant for this application. Recognizing the large gas volume as a desirable propulsion system for guns, the Navy embarked upon a gun propellant proqam. Utilizing a bulk loaded gun sysytem, the program failed when the gun was destroyed by the propellant detonating."

Jan 1, 1990

By M P. Simpson, J L. Mauk

The Golden Cross, low-sulfidation, epithermal deposit shows a number of features that are directly or indirectly related to boiling hydrothermal fluids. Occurrences of lattice calcite and their quartz pseudomorph equivalents in veins, and occurrences of adularia in veins and in the surrounding altered rocks in the vicinity of ore, are both direct evidence of deposition in the presence of boiling hydrothermal fluids. Loss of carbon dioxide causes calcite deposition (platy variety) near the level of first boiling, while adularia deposits due to the attendant pH increase along the cooling flow path. Indirect evidence of boiling include crustiform-colloform quartz banding, late massive calcite veins, clay-carbonate alteration in the shallow and peripheral parts of the ore zone, and the restricted vertical interval of precious metal mineralisation. The colloform quartz banding strongly resembles the banding in amorphous silica deposits found in geothermal surface pipes. This implies that fluids ascending the Empire Vein structure were saturated in amorphous silica. If so, then they must have undergone phase separation, which initiated at considerable depth (e.g. =1000 m) and very hot temperatures (e.g. =300¦C). On the basis of stable isotope data, late massive calcite veins appear to have deposited from CO2-rich steam-heated waters. Calcite deposited along heating paths as these waters descended into the upflow zone during late stage collapse of the hydrothermal plume. In active systems, such steam heated waters form by deep boiling. The high CO2 contents of these waters promote hydrolytic alteration and the formation of clay-carbonate alteration. Reaction path modelling using CHILLER and a deep, Broadlands-Ohaaki water as an analogue, shows that minerals deposit along boiling flow paths over discrete spatial intervals. Calcite and adularia deposit near the site of first boiling, followed by gold and then by amorphous silica. For deep boiling starting at 300¦C, these minerals deposit over a path length that exceeds 1000 m. The distribution of banded quartz and gold at Golden Cross are consistent with such a boiling model. However, the elevation of first boiling must have fluctuated over 500 m to account for the coincidence of lattice quartz (pseudomorphs of platy calcite) and adularia, crustiform-colloform silica and gold over distances of a few centimeters in veins. We deduce that a downward propagating boiling front and expansion of two-phase flashing in a flowing water column occurred during episodes of high vertical permeability and fluid flux in the Empire vein structure.

Jan 1, 2000

GOOD ventilation is recognized as an essential for the preservation of health, and laws have accordingly been framed in many countries for the provision of adequate ventilation in factories and places of public resort as well as in mines.Apart from the legislative enforcement of hygienic measures as a matter of public 'policy, the ventilation of mines has an important economic aspect, since it affects to a large extent the industrial efficiency of the workmen, and consequently the cost of mineral production. Until recent years the ventilation of metal mines has not generally received much consideration, and the importance of pure air has been sometimes overlooked. To the absence of explosive gases in such mines, and to the cost of the installation and working of mechanical ventilators, may generally be attributed disregard of adequate ventilation. In this paper it is not proposed to furnish statistics on the mortality and morbidity of miners, or a treatise on the medical aspect of the rock-dust problem, to further elaborate which would be superfluous, the deleterious effects of the latter having been...

Jan 1, 1912

A Novel Diagnosis and Evaluation Procedure for Flotation Plants

Sep 13, 2010

Planning for the Macraes Extension project highlighted the need for additional tailings storage availability. The possible solution of developing new tailings impoundments in Northern Gully, in tum, led to concerns being expressed by the regUlatory authority over the assimilative capacity of Deepdell Creek. Philosophical differences over the appropriateness of applying a seepage model used to set standards in consents for the original project resulted in the company re-evaluating the whole monitoring system associated with tailings disposal and seepage control. Re-evaluation indicated problems arising from the existing in-stream water quality monitoring in respect of protection of the aquatic ecological system and verifiability of results. A new monitoring system was designed relocating the compliance monitoring point out of the stream and into the gully containing the tailings impoundments giving greater certainty of monitoring results to all parties and providing improved protection for the aquatic ecology of Deepdell Creek.

Jan 1, 1993

By Peter Rubie, Toni Kojovic, Fengnian Shi

"Mining companies have recognized that characterization of ore breakage plays an essential role in the design and optimization of comminution circuits.Recently the Julius Kruttschnitt Mineral Research Centre (JKMRC) has developed a new breakage model incorporating the effect of particle size, and a new breakage characterization testing device, called the JK Rotary Breakage Tester (JKRBT), which allows rapid testing of particle breakage under high energy single impact and low energy repetitive impact conditions.Positive feedback received from mining company sponsors to the new technology has prompted the JKMRC to further validate the device and the model through a formalized validation program using machines designed and manufactured by Russell Mineral Equipment (RME). The first unit was installed and commissioned at the Anglo Platinum laboratory in Johannesburg in March 2007 and four more major mining companies will participate in the validation program in 2008, including Barrick, BHP Billiton, Rio Tinto and Teck Cominco. The results from validation tests at the JKMRC and Anglo Research have shown that the JKRBT generates statistically similar breakage parameters to the traditional Drop Weight Test, but with significant advantages over its predecessor. Application of the JKRBT in geometallurgical testing with the AMIRA P843 GeM project has confirmed the JKRBT device offers a rapid and consistent method for determining the hardness of drill core samples. The JKRBT has the potential to revolutionize ore testing, with applications in laboratory impact breakage characterization of rock samples, drill cores, coal and other materials. It also stands poised to significantly advance the process control and management of comminution circuits since the concept is readily adaptable to on-line ore hardness measurement.INTRODUCTIONMining companies have long recognized that the performance of a comminution machine such as a crusher or an autogenous / semi-autogenous grinding (AG/SAG) mill depends not only on the machine operating conditions, but also on the “hardness” of the feed material to be broken. This recognition has driven significant interest in laboratory particle breakage characterisation and testing. The laboratory breakage characterization tests can be roughly classified in two broad groups based on their primary breakage modes: tumbling and impact/compression. The famous Bond ball/rod mill tests (Bond, 1952 and 1961) represent the typical tumbling test and have become the industry standard for estimating the specific energy (kWh/t) of rod and ball mills. However, as the energy application in the single particle impact tests can be well defined and controlled, the latter have received significant attention in the last 30 years. It was estimated that mining companies worldwide spent over three million US dollars on single particle impact breakage characterization testing in 2006."

Jan 1, 2009

A hard lump char containing only 4 to 5 per cent ash, 0·25-0·30 per cent sulphur and a trace of phosphorus has been produced from Latrobe Valley brown coal by slow drying and carbonization of ordinary industrial briquettes at temperatures between 7000 C and 14000 C. The briquette char can be made with a variety of reactivities by varying the maximum temperature of carbonization; the higher the temperature, the lower the reactivity. The strength of the fuel compares favourably with metallurgical coke made from black coal, though it may not be quite so resistant to abrasion. Experiments in a small experimental cupola indicate that it will make a satisfactory fuel for use in iron foundries. It may also find extensive application as a smokeless fuel in other branches of industry and in household heating appliances.INTRODUCTIONVictoria, like South Australia and Western Australia, is apparently without 'significant deposits of black coal of coking quality but there are huge reserves of brown coal of high moisture content (60-66 per cent) in the Latrobe Valley (well over 20,000 million tons have been proved) and there are other important deposits in the south central portion of the State (Herman, 1952).For three decades Victorian industries, including a few metallurgical firms, have been using the briquettes made at the Yallourn factory of the State Electricity Commission of Victoria (S.E.C.). These briquettes, having a moisture content of about 15 per cent and a calorific value of approximately 9,500 B.T.U. per pound, are satisfactory for certain grate-type furnaces but they are not suitable for use in cupolas of other shaft furnaces because they disintegrate badly on rapid heating.

Jan 1, 1956

By Pengfu Tan

Xstrata Copper at Mount Isa in Australia has operated one copper Isasmelt furnace and four P-S converters. The phenomena of foaming occur in above 10% of converter operations. A thermodynamic model of copper P-S converter and a viscosity model of converter slag have been developed to simulate the slag blow and copper blow. The model predicts the chemistry and viscosity of copper skims during copper blow. The effects of oxygen potential, charge of dirty materials, slag carry-over, under-blowing, over-blowing, and temperature on the foaming and viscosity of copper skims have been discussed. Some improvements of the industrial operations have been presented.

Jan 1, 2006

An account is given of experimental apparatus for generating a short duration high velocity water jet and the effect of its impingement on various rock samples under air or water cover. The penetration was found to be highly dependent upon the rock structure; in general material with closely interlocking grains was resistant.The damage sustained by a stationary sample held close to the jet did not vary greatly whether the sample was in air or confined under a water layer; but when the sample was translated under the jet there was a marked increase in the damage sustained.Some consideration was given to the possible practical application of a water jet for deep hole drilling and an estimate made of the power requirements and transmission losses for such a system.

Jan 1, 1969

By Maurice Deul

For the first half of the 21st century, the United States will rely on the same mix of fuels it has for the past 50 years. Petroleum for the United States will cost more and availability will decline as developing nations modernize. Increased use of natural gas for electric power generation will result in stress on the gas supply. Coal will be the fuel of last resort. More than half the petroleum used is imported, about the same amount as used for transportation. Only coal can provide relief by fueling railroads through electrification while encouraging “piggy-back” trailer haulage, co-generation for manufacturing and expanded passenger service.

Jan 1, 2002

ALTHOUGH great progress has been made in flotation of the Broken Hill silver-lead-zinc ores, no paper dealing with this subject has been presented to the members of the Institute since James Hebbard's valuable contribution in 1913. Almost every discovery or development in the history of flotation has formed the basis 6f a patent, and but few experimentalists have overlooked the fact that their investigations might lead to the establishment of a patentable process. This, together with the aftermath of patent litigation, naturally resulted in secrecy being maintained in matters appertaining to the art, and the industry as a whole has consequently suffered considerably. Much valuable time has been wasted through numbers ofmen repeating work along certain lines, which, unknown to them, had already been thoroughly exhausted by others, whereas a lot of this would have been avoided by a freer interchange of information amongst those directly concerned. Owing to differences in the ore treated and the various applications of flotation concentration in relation to gravity methods, the flotation problems of the various mines differ considerably. This, together with the secrecy previously referred to, hasresulted in the development of numerous systems and machines, most of which would appear, to the casual observer, to comprise separate and distinct processes. The author has endeavoured to show how much these processes have in common with one another, and, at the same time, has tried to convey some general ideas on flotation to those members of the Institute who are not directly associated with this branch of concentration.

Jan 1, 1919

By Yeruva Ramanareddy, Sohail Wajid, Ahmed Shaz, K. Bhavani

"CP-06 is an NATM cross passage which connects up-line and down-line metro tunnels near Kilpauk Medical College, Chennai. It lies completely in loose silty sand to dense sand with water table almost touching the ground surface after Chennai floods. Pre-grouting was done before excavation to seal the area and to ensure no-loose pockets. The heading was excavated successfully but while benching excavation huge water ingress started seeping out. Sand also permeated along with water which became unstoppable due to cavity formation and caused the up-line tunnel to sink considerably. A large grouting exercise was carried out with different grout materials and techniques both from the ground surface and inside of tunnel to stop the water ingress and stabilize the tunnel. This paper describes the chronology of events that occurred in the tunnel during CP-06 issue. It elaborates all the different grouting techniques involved in the whole process of the tunnel stabilization. It includes a finite element analysis using Rocscience RS2 9.0 software showing the possible cause of sand incursion with water from the CP invert which lead to the tunnel settlement. This paper also describes the after effects and the lesson learnt from the whole incident.INTRODUCTIONConstruction of Metro Rails has become the latest alternative to cope up with the transportation demand of the growing urban cities population. L&T SUCG JV constructed Chennai Rail Metro Phase II Contract UAA-04 which included design and construction of approximately 4 km of route length of underground mass transit railway including 3 underground stations. This package also includes 12 cross passages which are NATM tunnels connecting upline and down-line side of TBM tunnel for safe evacuation of passengers in case of emergency. As per NFPA guidelines, this is a mandatory structure and there should be atleast one cross passage in 244m tunnel length.CP-06 is a cross passage connecting upline and downline tunnel between Pachiyappa College Station and KMC Station, in Chennai Metro. During the construction of CP-06, heavy water seepage of around 450 liters per minute was encountered during second round of benching excavation after full heading was excavated. An inflow of around 12-15 cum of sand and silt was also observed inside the tunnel along with the seepage water, which created piping inside the TBM tunnel causing it to settle continuously with time. A huge effort was made to stop the water ingress along with loose sand which was causing the running tunnel to settle, involving all possible grouting methods and temporary support installation."

Jan 1, 2017

By D. Wolfe, R. Cleminson

"The Aurora North mine has been operating for more than ten years, and is the source of over half of Syncrude’s bitumen production. The hydrotransport systems at Aurora experience high rates of wear, and mission lengths on current slurry pumps are nominally 1,500-2,000 hours. Recent work has enabled a better understanding of the significant adverse effect of large particle impingement damage to impeller vane leading edges - which is the known life determining issue for Aurora hydrotransport pumps. A new pump design has been developed and installed at Aurora, incorporating significantly increased impeller diameter and pumping vane lengths. The new pumps are expected to triple Aurora’s previous mission length for hydrotransport pumps. Part II of this paper will share actual hydraulic and wear performance observed in the first several months of operation, and draw comparisons relative to what was expected for these pumps in design / development.INTRODUCTION Slurry Pumps are Critical Equipment at Syncrude Slurry pumps are a key component in Syncrude’s operations. In a typical Aurora application, each 5000 HP pump stage helps move over 8,000 dry tonnes per hour of oil sand, plus an equal volume of process water that has been added to create the slurry. The average impeller life in oil sand hydrotransport service at Aurora has been nominally 1,500 to 2,000 hours, or 12 to 16 million tonnes of oil sand pumped. Generally, the slurry pump application at Aurora has proven very difficult to improve due to the unique combination of high sand abrasivity, 125 mm (5”) large particle top size (lumps), and high flow rate relative to basic pump size; a factor that results in unduly high impeller vane leading edge speeds for the service conditions."

Jan 1, 2014

By A G. Mitchell

Stream sediment geochemical analyses were collated from open-file mining company reports and assembled in the REGCHEM computerised database at the Institute of Geological and Nuclear Sciences Limited. The database operates on an IBM-compatible PC microcomputer using an application programmed in dBASE IV and termed GEOEXPL. By August 1992, data for 6383 stream sediment samples from 6335 different sites in the Coromandel Peninsula region (Hauraki Goldfield) were entered, giving a total of 29 292 separate elemental analyses. Preliminary statistical analysis using PROBPLOT on a set of data collected by AMOCO from the Mahakirau-Whangapoua area shows that these data are a complex mix of subpopulations related to mineralisation and different source rock types. Thresholds of 37 ppm copper, 31 ppm lead, 112 ppm zinc, and 2.3 ppm molybdenum, defmed by arithmetic models for the combined data set, separate the individual element sets into 'first order anomalous/lesser anomalous and background' subpopulations as follows: copper five per cent/95 per cent, lead five per cent/95 per cent, zinc one per cent/99 per cent, and molybdenum 15 per cent/85 per cent.

Jan 1, 1992

Jan 1, 1967

By Z. Hyder, M. Karmis

Underground or In-situ Coal Gasification (UCG or UICG), though not a new concept, is now attracting considerable global attention as a viable process to provide a "clean" and economic fuel from coal. Applying improved UICG technology to gasify deep, thin, and low-grade coal seams could vastly increase the amount of exploitable reserves. However, it is imperative that further development of this technology is based on integrating UCG practices and potential environmental impacts with accepted sustainability frameworks and processes. This paper evaluates the potential of UCG to conform to frameworks such as MMSD (Mining, Minerals and Sustainable Development), Natural Step and Green Engineering, in order to define its "sustainable" potential. The paper also discusses the potential contributions of UCG to sustainability during its design, operation, closure, and post-closure phases.

Jan 1, 2011

By J. Bruce Clemmer, M. F. Williams, B. H. Clemmons, Carl Rampacek, R. H. Stacy

"INTRODUCTION This report is the first of several dealing with the application of flotation methods for beneficiating the calcareous and siliceous red iron ores and ferruginous sandstones of the Birmingham district. The flotation study was part of a general investigation of the concentratability of various iron ores of Alabama and other Southeastern States undertaken by the Southern Experiment Station of the Bureau of Mines, United States Department of the Interior, in cooperation with the University of Alabama, Tuscaloosa, Ala.Batch testing and pilot-plant flotation testing of the calcareous red ores of the Birmingham district have been in progress for several years, and although some phases of the study are not yet completed, enough data are available to indicate that many of the ores will yield marketable-grade concentrates with good recovery.The first flotation tests on the calcareous red ores employing conventional methods either the iron oxides or the siliceous gangue materials failed to give the desired results. The inferior separations obtained or prohibitive reagent requirements made the methods unattractive. Other more effective flotation methods were sought. A laboratory study of various reagents was undertaken. It resulted in the development of two attractive methods embracing anionic flotation of the activated siliceous gangue from the retarded iron oxides. The methods were similar in that fatty acid or soap-collecting agents were employed in strongly alkaline pulps to float the naturally activated quartz from the iron-ore pulps. The methods differed, however, in the addition agent employed to retard the hematite or hematite and calcite. By proper choice and quantity of the addition agent, the calcite could be floated with the quartz or retarded with the hematite as desired. Ability to recover or reject the calcite gives added flexibility to the separation. Although the methods have their limitations and cannot be considered ""cure-alls,"" they have given encouraging results on a number of calcareous red ores that heretofore proved difficult to concentrate by conventional flotation procedures."

Mar 1, 1945

Jan 1, 1968

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

By Peter Dowden, Trevor Carter, Allan Moss, Bruce Downing, Richard Beddoes

Traditionally (with a few exceptions) tunnel boring machines (TBMs) have been utilized on tunnel projects where the risks associated with deep tunnels (rock burst, squeeze, etc) are low (or expected to be low). This has generally been due to the extremely adverse consequences of entrapping or damaging a TBM under such conditions; but also due to the relative difficulty of dealing with these ground conditions in the confined working area of a TBM, in comparison to a drill and blast heading. This paper review the constraints of operating a TBM in a deep tunnel and discusses related project experience, particularly recent and current experience with TBMs in the deep Alpine Base Tunnels. Potential future applications of TBMs in the development of large, deep underground mines are also discussed.

Jan 1, 2007