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A commercial Philips X-ray Fluorescence (X.R.F.) analyser was converted to an experimental instrument suitable for determination of the accuracy to be expected of X.R.F. on line analyses of concentrator slurries. Problems with stability of slurry sample presentation were eliminated by a number of minor modifications.By the use of multiple linear regression techniques instrument calibration equations including error terms were determined for copper flotation feed slurries. Results indicated that the accuracy of copper and iron analyses of flowing slurry samples could approach that of static pressed powder samples.Possible means of reducing the error terms to a level of at least that of pressed powdel' samples involve alternative methods of compensating for the per cent solids in the slurry, Design is under way for installation of a plant unit.

Jan 1, 1968

By Thomas M. Barczak

Roof support systems are necessary to provide stable mine openings and much research has been conducted to design a variety of roof support systems that will function in various manners to ensure that stable ground conditions are achieved. Despite these advancements in technology, mistakes continue to be made in the evaluation and/or installation that significantly degrade the support capability or lead to erroneous determinations of support expectations. The purpose of this paper is to discuss misconceptions about how roof supports perform and factors that impact their performance. The goal is to present practical information that will assist mine operators and engineers in selecting, installing, and evaluating roof support systems properly, and help them to avoid mistakes that can lead to erroneous expectations and potentially catastrophic results that may lead to roof falls. The paper is limited to a discussion of secondary roof support systems and powered roof supports such as longwall shields.

By T. Lindstad, J. Kaczorowski

The Boudouard reactivity of single cokes produced from selected bituminous coals and commercial cokes has been investigated in a thermo gravimetric furnace. The effect of potassium as a catalyst for this reaction was studied, as it is known to accumulate in ferromanganese furnaces. A gaseous impregnation technique using K2CO3 as the potassium source was applied to impregnate the coke samples. The reactivity experiments were designed to simulate conditions occurring in an industrial furnace, as used for production of Mn-alloys. The coke particle size varied from 3.35 to 6.63 mm, while the temperature was maintained between 800- 1100oC with a gas composition from 50 to 75% CO2 in a CO/CO2 mixture. To determine the catalytic effect of potassium, the concentration varied from a fraction of a percent up to 15%wt. The results show that single chars vary significantly in reactivity, depending on the properties of the parent coal, while commercial cokes exhibit similar reaction rates. Temperature and partial pressure of CO2 have the strongest influence on the reactivity, while the influence of gas flow rate and coke particle size were found to be negligible. The catalytic studies revealed that the relative reactivity of non-impregnated samples are preserved after the impregnation, so the least reactive coke is still the least reactive after the impregnation for the whole range of potassium loads. Also, it has been confirmed that the Boudouard reactivity reaches a plateau at potassium concentration of 4%wt.

Jan 1, 2007

By Brown H. R, Wright E. A

The authors identify the workable coal seams, their distribution in relation to quality and economic occurrence and relate their analytical characteristics to industrial use. The development of established collieries is also discussed with regard to increased production demand.The authors also indicate the potential of the coal resources of the Southern District and postulate their ultimate development.INTRODUCTIONThe Southern Coalfield yields 30 per cent of the total production of bituminous coal in New South Wales. The economic potential of the coalfield was examined last by Harper (1915). Since that time additional knowledge has been gained by prospectors, mining companies and public authorities. Expansion in the steel industry and the building of power stations on the coalfields together with improvements in fuel technology, mining methops and road transport have resulted in production of coal from seams mice thoughtto have no economic value.DESCRIPTION OF THE COALFIELDFor the purpose of this paper the term Southern Coalfield includes also the South-Western Coalfield which together comprise the following Coal Districts:IllawarraDouglas ParkWollondilly-NattaiMoss Vale-Berrima (Hanlon, 1953).Geographically the coalfield is contained by the Illawarra Range in the east, the Shoalhaven River to the south, the Wollondilly River to the west, and in the north by a line...

Jan 1, 1958

By Mark E. Hammele

A number of new thoughts have recently emerged concerning the role of air decks, stemming, gas confinement and gross motion in specific blasting environments and applications. Field research in full-scale production environments is based on the theoret ical work f i rst proposed at the Universi ty of Maryland’s Fracture Mechanics Laboratory.

Jan 1, 1989

By Patricia Martínez Nicolás

Nickel and ferronickel are some of the major components in the production of special alloys; however, the energy consumption for their production greatly increases their price. A cheaper option could be to use NiO and a reducing agent. This work presents experimental and theoretical analysis to estimate the effect of slag basicity and amount of reducing agents on the NiO reduction from the slag which interacted with molten steel at 1600 °C in an EAF. The slag system contained CaO, SiO2, CaF2 and NiO together with a reducing agent, ferrosilicon or carbon. The NiO content in the slag was 25 mass%. The amounts of the reducing agents (Si and C) were 1 to 4 times the stoichiometric mass to reduce NiO. The CaO/SiO2 ratio was 1.5 and 2.5. The kinetics of the process was very fast since after few minutes the maximum nickel yield was obtained. The slag basicity had a negligible effect on the reduction of NiO.

Jan 1, 2006

By A. C. Fieldner

ONE of the important functions of the Bureau of Mines is the, analysis of coal from every coal-mining State and Alaska. These analyses are being published for use of Government officials and the public. In connection with analytical data showing composition and quality of coals of the States, consumers, Producers, and the general public will be interested in a brief description of the geologic structure of the coal basins, typical mining conditions in the several districts, and the principal economic data of the industry. These publications have therefore heel) designed to include such features to present concisely the principal facts regarding occurrence, reserves, duality, characteristics, production, and uses of coals of each producing State.

Jan 1, 1952

By Jeffrey A. Pontius

The Cresson gold deposit is in the southcentral portion of the Cripple Creek mining district in central Colorado (Fig. 1). The deposit is hosted by a series of 32 Ma (Kelley, 1995) felsic to mafic, alkaline volcanic rocks that were deposited in a diatremal environment. Mineralization in the Cresson deposit is structurally con-trolled. It occurs as disseminated and vein type. Gold deposition is closely associated with potassium-pyrite metasomatism and quartz-telluride vein development(Pontius, 1992). The Cresson deposit is owned by the Cripple Creek and Victor Gold Mining Co. (CC&V), a joint venture between Pikes Peak Mining (67%) and Golden CycleGold (33%).

Jan 1, 1996

By Frederick H. Raab

The electromagnetic retransmission system is a new, automated method of locating trapped mine workers. This technique overcomes many 1 imitations inherent in electromagnetic direction finding by reducing the effects of the conducting ground to an acceptable maximum, by finding position accurately in the presence of antenna tilt, and by eliminating the need for the receiver to be located directly above the subsurface transmitter. Three transportable three-axis magnetic-dipole transmitters on the surface create a system of electronic grids in which the phases of the downlink Signals convey position information. The subsurface retransmitter modulates the uplink carrier of the existing beacon transmitter with the received downlink signal; the coal-pillar loop antenna is used for both receiving and transmitting. The uplink receiver uses a three-axis antenna and extensive digital signal processing. A small computer integrates data, estimates position, and controls system operation through VHF-FM communications. Both coal-mine and deep-mine operation are possible by selecting appropriate transmitting power and signal frequencies. This report shows such systems to be both feasible and practical.

Jan 1, 1980

By Matters, R T, Coldham, Slee, J C, R J, Wallman

The Committee desires to thank the managers of the various mines along the line of lode for their hearty co-operation in its labours. It would also extend thanks to Messrs J C Moulden, Howchin, Twelvetrees, and the West Australian Geological Surveyfor various information; to Messrs J G Dreyer, S Pope, T Read, P Moncrieff, R Williams, and W J Rose for analyses; and to a number of local gentlemen for advice and help. Professor Skeats, of Melbourne University, gave much valued assistance in petrology, and Mr Herbert Lavers kindly undertook the study of the garnets.INTRODUCTIONThe famous Broken Hill lode is situated in a low range of hills, the Barrier Ranges, near the western border of New South Wales. It has been worked since 1884-fust for silver, then for silver and lead, and at present for lead, silver, and zinc...

Jan 1, 1910

By W. G. K. Fleming

The general history of piling is traced up to the present time with regard to the evolution of methods and materials. The processes have been strongly influenced by developments in basic equipment and industrial change. It is noticeable that in the twentieth century more progress has taken place than in the many previous centuries. It has been strongly influenced by the general development of Soil Mechanics. Test loading is probably the most effective way to assess the success of designs and many empirical relationships have been challenged through it. As we approach a new century it appears that it will be an age of rapid equipment development, with much enhancement of understanding of what has been done. Processes of automatic construction and testing will becoming commonplace. These changes will narrow the limits of conventional scatter that have come to be accepted and to a large extent will be driven by political efforts to curtail energy consumption, to raise standards of quality and reliability, and to conserve the environment. 1. Ancient history. Piling is an ancient art. Its first mention in history is from Herodotus, the first person to commit an account of his times to the written word in the years 557 to 479 BC. He evidently had a strong interest in engineering matters because he wrote of building, brick making, reinforced brickwork, river training, canal building, bridge construction, tunnelling and its acoustic detection and piling. The piling reference comes from Book 5 at paragraph 16.

Jan 1, 1999

By Paul D. Tomlingson

During the next several months, SME’s E-Newsletter will feature 15 articles on maintenance management. The articles may be read online or downloaded and distributed within your organization. They will address maintenance management topics, offer guidelines to mining managers and provide techniques that the maintenance manager can use. The articles will stress equipment management, a strategy that the mining industry has accepted as a modern replacement for outdated maintenance practices. Equipment management is the mutually supportive interaction of all mine departments as they establish equipment needs, procure equipment, test, commission, operate, maintain, modify and eventually replace equipment. The successful application of equipment management principles can quickly and reliably produce cost reduction and performance improvement results while providing a dependable way of sustaining them. Equipment management embraces modern management techniques. These include reliability-centered maintenance, life-cycle costing, capital performance, the effective use of information and productive organizational models.

Jan 1, 2003

By W. L. Dare

This publication is one of a series prepared by the Federal Bureau of Mines on methods and costs of producing uranium ore on the Colorado Plateau. The information it contains was gathered in 1955-58 and applies to eight small operations. (See fig. 1.) Mining costs have increased since the data were I collected, but the information should be helpful in estimating future costs I at similar deposits. The Bureau of Mines had early experience in the production of carnotite-type ores on the Colorado Plateau.3 4/ Under a cooperative agreement with the National Radium Institute in 1914-16, the Bureau mined and concentrated carnotite ore for recovery of radium, uranium, and vanadium. The ore was taken from claims in or near Long Park Montrose County, Colo., about 3 mi. south of La Salle Mining Co.'s La Salle mine, which is one of the mines described in this report. The Bureau leased the claims from Crucible Steel Mining & Milling Co., a subsidiary of Crucible Steel Co. of America, and from 1914 to 1916 produced 990 tons of high-grade ore, containing 2.6 pct. U308, and about 2,000 tons of mill-grade ore, containing 0.85 pct. U308. The high-grade ore was shipped directly to a radium-recovery plant built in Denver in 1914 under the cooperative agreement. There, commercial methods of extracting uranium, vanadium, and radium from carnotite ores were developed by Bureau personnel. The lower grade ore was concentrated at a small mill in Long Park before being shipped to Denver. The final recovery was 69,000 lb. of U308 and 8.8 g. of radium. The direct mining cost of producing the high-grade ore, including the labor to hand sort and sack it, was $35.96 per ton. Freighting the ore 58 miles to Placerville, Colo., the nearest rail point on the Rio Grande Southern Railway, cost $25.28 per ton, which included $4.55 per ton for ore bags and twine. Four-or six-horse teams pulled two wagons in tandem and made the

Jan 1, 1961

By H. E. Powell

The magnetic susceptibility, the geographical source, and associated minerals are given for 44 copper-, 26 lead-, and 19 zinc-bearing minerals. Of the 44 copper minerals/ all had a susceptibility of less than 15 X 10-6 cgs, and about 20 percent of them were diamagnetic. Of the 26 lead minerals, all had a susceptibility of less than 11 X 10-5 cgs, and almost half of them were diamagnetic. And, of the 19 zinc minerals, all except four had a susceptibility of less than 9 X 10-6 cgs, and about one-fourth of them were diamagnetic.

Jan 1, 1968

By Kyle W. Charlton

The Bureau of Mines utilizes special testing methods for the analysis of underground mine atmospheres for use during or after mine disasters and fires. These methods depend upon drawing sample gas to the surface through multiple tube bundles with the subsequent analysis of grab samples or the automatic analysis by often remotely located instruments on a continuous, 24-hour basis. During cold weather, low ambient temperature causes condensation and freezing of condensable vapors in the sample which can result in delayed response times or complete blockage of the sample line. This report covers research and resulting development conducted by the Bureau of Mines to produce a reliable method to selectively remove condensable vapors and particulate in the sample gas stream under worst-case field conditions. The effort resulted in two prototype systems which have greater field utility than originally anticipated. The innovative project resulted in two patent applications submitted through the Bureau of Mines.

Jan 1, 1981

By Masanobu Masukawa, Toshio Shiota

The shaft-type ferromanganese smelting furnace (SF) at Mizushima Ferroalloy Co., Ltd. has been in operation since startup in 1985 and is continuing to perform smoothly. Production has been increased from the original design capacity of 270t/d to 350t/d by various operational improvements. As a productivity index of the shaft-type furnace, production of 350t/d is equivalent to productivity of 0.9t/m3/d (daily production/cubic capacity of furnace). Recently, various operational improvements were implemented to achieve productivity of 1.0t/m3/d or higher, including oxygen enrichment operation, increased tapping frequency, maintenance of the throat profile, and operation with small lump coke. The target productivity of 1.0 t/m3/d was achieved in January 2005. This report describes the improvements introduced as part of this high productivity technology.

Jan 1, 2007

By C. Pritchard

John Marks said in his acceptance of the Hartman Award in 2008 ? ?I guess that without the occasional complaint, your mine is probably over-ventilated? (Marks, 2008). Miners are seldom in this situation and often spend much of the time trying to find enough air to keep the operation running. With examination there are some things that can be done to make the best use of ventilation systems. Should there be surplus air, in which some of these options may result - financial and other benefits can be obtained. Some of the issues mine operators have needed to address recently are increased airflow requirements to dilute diesel particulates in metal and non-metal mines. Also, operations are faced with demands from reserves that are deeper, hotter and further away from fans and shafts, not to mention increased production demands. Mine ventilation air is a costly commodity, especially by the time it has been heated or cooled and moved to the bottom of the shaft and through the mine airways. Most of the options presented in this paper are useful for metal non-metal operations but some may be applicable to coal too. OPTIONS FOR IMPROVEMENT Some of the areas to be addressed are shop ventilation methods, auxiliary equipment areas, dedicated intakes and returns, optimizing development, examination of mine airway utilization and alternative ventilation methods. UNDERGROUND SHOPS First, examine what is being done with the underground shop air. If it is being coursed directly to the returns there may be some potential to better utilize this, in most cases, relatively contaminant free air. Research the legal options for ventilating mine shops. MSHA regulations in 30CFR 57.4761 (1) allow the following options: To confine or prevent the spread of toxic gases from a fire originating in an underground shop where maintenance work is routinely done on mobile equipment, one of the following measures shall be taken: use of control doors or bulkheads, routing of the mine shop air directly to an exhaust system, reversal of mechanical ventilation, or use of an automatic fire suppression system in conjunction with an alternate escape route. The alternative used shall at all times provide at least the same degree of safety as control doors or bulkheads. Discussion This regulation gives some operators flexibility in ventilating underground shop facilities. If shop air is to be coursed through the work area, and then directly to the mine return, the question should be asked ? is the quality of air good enough to be reused in the mine, and if so, what are the risks? Can the risks be accommodated and managed to accomplish the change? If so, a considerable increase in mine level airflow could be attained by reusing shop air. Clearly, regulations are a minimum standard, and can be exceeded. Metal non-metal mine regulations are not as specific as coal due to the multitude of different mining methods and conditions utilized. Risks must be thoroughly examined and addressed to assure a safe environment. Issues Determine what contaminants are being produced in the work area ? welding fumes, diesel exhaust, paint fumes, chemicals and solvents, etc. Survey the area and determine exposures. MSHA requires exposure monitoring in 30 CFR 57.5002 (1) of dust, gasses mists and fumes to assure air quality is being met. Perform surveys and examine existing data to quantify personal and area concentrations of contaminants. Often there is adequate circulation such that exposure levels in shop work areas are low. After sending shop air back into the system any contaminants would be further lowered by dilution with other mine intake air downstream. Look at the shop work schedule. If only on day shift, the other two shifts and possibly weekends have no activity or source of contamination to affect the ventilation system. The worst case planning scenario would be a shop fire. Study and simulate how this would affect the mine and shop area. MSHA regulations require an escape route and a fire suppression system be installed and maintained as follows in 30 CFR 57.4671 (1): (d) Automatic fire suppression system and escape route. If used as an alternative, the automatic fire suppression system and alternate escape route shall meet the following requirements: (1) The suppression system shall be? (d)(1)(i) Located in the shop area; (d)(1)(ii) The appropriate size and type for the particular fire hazards involved; and (d)(1)(iii) Inspected at weekly intervals and properly maintained. (2) The escape route shall bypass the shop area so that the route will not be affected by a fire in the shop area. Case Study In an underground room and pillar mine, active mine workings were advancing further away from the mine shaft with deteriorated returns and leakage having a negative effect on ventilation airflows to the face. Mine level airflows were 236 m3/s (500,000 cfm) and shop airflows were 24 m3/s (50,000 cfm) (see Figure 1A). No additional capacity was available at the main surface fan. A solution was to utilize the shop air then send it to the mine areas instead of directly to the return. Considerable information on shop air quality and exposures from many years of operation was examined and no negative data was discovered. A risk analysis determined that moving forward with a shop air reuse program was desirable. A plan was developed, analyzed and decision to proceed approved by mine management. The change was simulated on the computer with the USBM/MTU MFire program before being implemented. This included utilizing fire scenarios to examine potential exposures to inby mining sections and plan escape routes. A monitoring system was designed and installed in cooperation with the US Bureau of Mines to monitor carbon monoxide

Jan 1, 2009

The use of solid state detector and radioisotope x-ray source for x-ray fluorescence analysis is illustrated by analysis for iron, copper, zinc, tin, and lead in about 700 samples taken from Australian mineral process streams. Limits of detection based on counting statistics (3 standard deviations) range from 0·001 to 0·004 per cent by weight element. The analysis accuracy was usualIy between 2 to 10 per cent (rms) of the mean element concentration and was determined by comparison with assays supplied by mineral companies. In most cases the main cause of error appears to be due to this assay and not the x-ray fluorescence technique.Some potential fields of application of solid state detector and radioisotope x-ray source for analyses in the mineral industry are indicated.

Jan 1, 1974

By C. J. Allen, L. Battiston

"Introduction It has long been recognized by the hot-dip galvanizing industry that the characteristics of the galvanized coating can be influenced significantly by steel and pro cessing variables. Probably the variable of most concern to galvan izers today is steel chemistry. More specifically, the problem is the excessive reactivity of continuously-cast, silicon-bearing steels. In the past, structural steels processed by general galvanizers were in the low-to-medium ca rbon category and contained silicon at either low impurity levels (as with rimmed steels), or less than approximately 0.10% (as with semi-killed steels). The structures of the coatings produced on such steels are characterized by dense, compact layers of delta and zeta iron-zinc alloy phases and a distinct outer layer of eta zinc, which usually imparts a bright shiny appearance to the coating. The presence of silicon in steel, above the so-called semi-killed levels, is known to cause marked stru ctural changes in galvanized coatings. Such coatings are characterized by a relatively thin delta layer, a thick , coarse zeta layer and frequently an absence of the eta layer. The eta phase, comprising zinc which is carried out of the bath during withdrawal of the work, can be consumed by the continuation of the coating reactions until its temperature drops to the solidification point. This results in a dull grey and often mottled surface instead of the usually bright metallic appearance. These galvanized coatings are usually much thicker than coating specifications requ ire and they are usually more brittle and have poor adhesion to the steel. In service, these coatings tend to develop a rust-like discolouration. With the wider use of continuous casting by the steel producers and the associated additions of silicon in this process, the problem is becoming more important and receiving greater attention from the galvanizing industry ."

Jan 1, 1987

CAPTAIN JOHN H. BALLAMY John H. Ballamy, Captain on the Regimental Staff of the 103d Engineers, was killed near Fismes, on August 9, 1918. Captain Ballamy was born at Plymouth, Pa., in 1886 and graduated from the High School of that town in 1903. In the following year he began work as a coal miner, and at the same time began the study of mining engineering in the evening and any other spare time. He continued this diligent and energetic practice for many years. For sixteen years he continued in the employment of the Delaware, Lackawanna & Western Railroad Company's coal mining department, first as a practical miner, next as rodman on the survey corps, of which he soon became chief, then draftsman and mining engineer in the company's office. In January, 1916, he was promoted to the position of district engineer in charge of mining engineering work. He became a member of this Institute in September, 1917. CAPTAIN JOHN H BALLAMY. Captain Ballamy's military experience began at the same time as his engineering practice. He was a charter member of Company A, Engineers, N. G. P., which was organized ten years ago. He saw service on the Mexican border as First Lieutenant of this Company, and remained in that position until November, 1916. In July, 1917, he was again called into service and was sent to Camp Hancock, Ga., with the 103d Regiment of Engineers. Before joining this regiment he attended a school for officers at Fort Sill, Okla., where he received special training in field fortifications. In December, 1917, he was commissioned Topographical Captain on the Regimental Staff, and in April, 1918, preceded his regiment by about six weeks to France, where he again attended an officers' training school. He rejoined his regiment on July 15, near Chateau Thierry and was killed near Fismes on August 9, 1918.

Jan 11, 1918