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By Iwueze Anaekperechi Rose

The International Labor Organization has declared mandatory adequate provision of safe workplace and safety for all workers in all occupations including the mining sector. Early scientists like Agricola (1559) who studied the health of Miners, found that there are peculiar health problems associated to their work and working environment. This unsafe working condition was one of the major factors that resulted to the Industrial revolution in England and eventually led to the establishment of regulations and laws guiding operations in all workplaces and workers in England and all over the world. Recent studies by Heinrich suggested chains of events of safety issues in the mining sector. Occupational injuries, accidents and ill health have huge social and economic implications on workers, their families and communities. Top mining top issues are respiratory diseases, noise, explosives, ventilation, fire, and explosion. However, one of the principal mechanisms for achieving Occupational Health and Safety (OHS) goals and mapping the future is government regulations of employers. In Nigeria, the situation is not different; mining operations are equally hazardous and have far reaching implications. In 1995 the Ministry for Solid Minerals was established to focus on the development of other categories of mineral products ranging from gold, coal, uranium, and tantalum deposited across the country. Prior to this an Act of Parliament Act Cap 121 of 1946, was in place to regulate amongst other contents mining safety. This was subsequently reviewed following the incidence of Lead poisoning resulting from small scale miners processing gold ore highly contaminated with lead in Zamfara state (northern Nigeria). Hundreds of children died as a result of exposure to lead poisoning, it was clear that the regulations were not sufficient (details to be discussed). However, advances have been achieved in mining engineering since then. A review team was constituted to provide a more stringent law to regulate mining operations in Nigeria. The strategies for mapping the future of OHS in mining engineering will employ amongst others setting and adopting ISO/ILO standards and enforcement; providing technical assistance; and establishing sustainable developmental structures as surveillance and compensation. The management systems approach was also developed as a result of cases of accidents. The accepted international standards guidelines and requirements will be proposed. Furthermore in mapping the future for Mining Engineering, it is suggested that most countries have their own management strategies and legislation to improve safety of workers through greater consistency and efficiency of OHS programs. Some American researchers came up with the Safety Engineering Model. The Australian Mining Council of mineral and petroleum resources after the Catastrophic Maura Disaster developed the National Mine and Safety Framework. In Canada, after the Hillcrest mine disaster in 1914, Allan shaft coal mine catastrophe in 1918, Westray mine explosion in 1992 and other disasters, Occupational Health and Safety Act R.R.O 1990 was sufficiently developed to provide adequate safety conditions and standards. In Nigeria after the disastrous Zamfara lead poisoning, which claimed the lives of hundreds of children due to exposure and lack of appropriate safety measures, stringent measures were developed by the federal ministry of Justice to address and regulate mining process in Nigeria.

Aug 1, 2013

By Xiang Sun

Microwave heating has been used in numerous industrial processes due to its great advantages when compared with conventional heating methods. However, microwave heated products can be affected by non-uniform temperature distribution resulting from the mechanisms of microwave heating. To overcome this problem, a critical step is to have a temperature-time profile. In order to characterize and evaluate microwave heating effects, an accurate temperature measurement is needed. This paper discusses the possibility of applying several temperature measurement techniques in microwave processing. Both contact and non-contact methods are introduced and compared.

Jan 1, 2006

By T. R. Skerry, H. P. Hudson, T. E. Warren

"ALTHOUGH coal is generally the cheapest fuel on the basis of heating value it has been at a disadvantage in competition with other fuels because means have not been available for efficient •Conversion of its thermal energy to mechanical work. Taking the •railway application •as an example, the cost of Diesel oil is about three times that of its thermal equivalent in coal, but the overall efficiency of a Diesel locomotive is about five times that of a coal-fired steam locomotive. Accordingly, the Canadian railways are replacing all coal-fired steam Locomotives, as they are retired from service, with Diesel units. This conversion in itself represents a major loss to the coal industry because the value of railway fuel is approximately 130 million dollars per year, and there are other applications in the medium power range where oil is displacing coal. There is, therefore, a strong incentive to attempt development of an efficient coal-burning engine.Coal has never been a promising fuel for reciprocating internal combustion engines because of the time required for its combustion in pulverized form . This is not less than one-tenth of a second so that the speed of such an engine would have to be very slow. There are also serious difficulties of a mechanical nature arising from the necessity for intermittent combustion and the use of close-fitting pistons."

Jan 1, 1952

By Y Cai, B Hebblewhite

In this paper, the Australian thick coal seam underground mining potential is highlighted and the characteristics are investigated by analysing a thick seam database. It is clear that thick coal seam resources should be mined with a high recovery, productive, efficient as well as a safe and reliable mining method. Longwall Top-Coal Caving (LTCC) is the most recent thick coal seam mining method which has been developed and extensively used in China for the last ten years. The successful applications indicate that this method has a very high recovery and productivity rate and less development cost in comparison with any other thick coal seam mining method. One of the aims of the current study is to seek potential for the application of LTCC as a thick seam mining method in Australia. In this paper, preliminary results of investigation on Australian thickseam potential are given and results of data analysis for potential LTCC seams in Australia are described. The outcome of this study shows a great promise for the application of LTCC in Australian coal industry.

Jan 1, 2002

By J. F. Brune

This paper analyzes the explosion hazard resulting from the formation of methane-air mixtures in the mined-out gobs of underground longwall coal mines. Although direct examinations of the gob atmosphere are difficult due to the inaccessibility of these gobs, evidence from methane drainage practices and investigations of numerous mine explosions suggests that explosive methane zones can form within longwall gobs. Explosions and fires resulting from these methane accumulations have led to severe and fatal injuries to the miners. Most recently, this was demonstrated in the explosion of the Upper Big Branch Mine in West Virginia, where 29 miners lost their lives.The paper also reviews current research on numerical modeling of gas flows in longwall gobs and outlines how targeted injection of nitrogen into gobs can effectively reduce the volume of such explosive methane zones. The paper concludes that comprehensive monitoring of gas compositions, along the accessible fringes of the gobs along with inertization, improved ventilation schemes and further research are necessary to control this explosion hazard and make mining operations safe.

Jan 1, 2013

The largest investment in mining equipment in Caterpillar?s history ? The F series mechanical and electrical drive trucks ? is rapidly advancing. Caterpillar showcased the 793F and 797F mechanical drive trucks and the 795F ac electric drive truck at MinExpo in 2008 and have continued testing since then. The 793F and the 797F have accumulated more than 75,000 hours of field testing and have proven their performance capabilities and their durability. The new Cat C175 engine that powers them has racked up 130,000 hours of field testing in mining trucks and more than 120,000 hours in power systems. Because of the success of these field-follow programs, the 793F is targeted to go into full production within a few months and the 797F late this year. Caterpillar engineers have been testing two 795F ac prototypes at the Tucson Proving Grounds in Arizona. The development program has provided input for the construction of a new 795F ac in Decatur, IL. The new truck recently shipped to a copper mine in North America where it will serve as the first field-follow 795F ac as it works at the mine. The 313-t- (345-st-) capacity 795F ac will enter a new size class for Caterpillar, and, as a result, the primary focus of the Caterpillar ac electric program has been on the 795F ac. The commercial launch date will be defined as the field-follow program progresses. ?It?s fitting that soon after producing the 50,000th Cat off-highway truck, we are now shipping our first ultra-class ac electric drive truck to a mine,? said Chris Curfman, president of Caterpillar Global Mining. ?Our new trucks further solidify our position as the one manufacturer to provide unparalleled options and unmatched customer support.?

Jan 1, 2009

By R. W. Kobler

The pelletizing process for low grade iron ores has undergone continual changes since its inception over twenty years ago. These changes have necessitated filtration equipment changes in order to produce a product suitable for balling. With modern techniques it is now possible to produce pellets of 68% Fe from ores containing as low as 26% Fe. Low grade ores require fine grinding to liberate impurities This shift to finer grinds over the years has necessitated major changes in the filtration steps. Techniques are now available for producing suitable product from ores with Blaines as high as 3600 cm2/gram. This has been made possible by the development of high performance filters. Recent developments have reduced maintenance costs and produced higher production reliability. The paper discusses iron concentrate filtration from its beginning to present day design. It will be shown that the dewatering step prior to balling has gone through four generations of filters. Particular emphasis is placed upon hydraulic studies which have allowed today's optimum designs.

Jan 1, 1978

By José Salas, Vicente Salas, Fredy Butrón

El objetivo principal, de la presente investigación aplicada, es determinar cuantitativamente, la viabilidad tecnológica, del aprovechamiento de la energía eólica, minihidráulica, y combinadas de los ríos de las cuencas bajas de las cordilleras, y su sostenibilidad económica; tomando como ejemplo característico, la cuenca baja del rio Ocoña en Arequipa, Perú. Como objetivos parciales, se estudia de forma individual, el tema eólico, minihidráulico

Sep 29, 2023

By A. McEachern

At the Annual Meeting of this society, held in Halifax last year, a paper entitled "Closed System Breathing Apparatus" was read by I. C. Mackie, metallurgist, British Empire Steel Corporation. Coming from such an authority it was most instructive and illuminating. The purpose of the paper was to emphasize the necessity of a full supply of oxygen and the danger of oxygen shortage in the use of rescue breathing apparatus. In connection with this he pointed out: "In times of emergency, when life is at stake, rescue men cannot be restrained from using their utmost endeavor, and unless the apparatus is adequate to meet the heaviest load, the result may be fatal to the wearer. The body's demand for its oxygen requirement is absolutely imperative and must be granted at once. We can do without food for many days and without water for many hours, but we cannot do without full requirements of oxygen even for a few minutes. Furthermore, the victim of oxygen shortage gets practically no warning. He may fall helpless or unconscious before realizing that he is in a serious condition." Hence the necessity for expelling all the nitrogen from the breathing-bag and filling it with pure oxygen; also filling the lungs of the wearer with oxygen before he begins to use the breathing apparatus. This practice is general at all the collieries under the British Empire Steel Corporation.

Jan 1, 1924

By I. C. Brown, J. F. Henderson

"IntroductionThe Yellowknife greenstone belt lies along the west side of Yellowknife bay on the north shore of Great Slave lake, some 600 miles north of Edmonton, Alberta. The producing gold mines along the belt include the Con-Rycon and Negus which came into production in 1938 and 1939, and the Giant Yellowknife, which followed in 1948. In addition to these, the Akaitcho and Crestaurum mines are potential producers and there are several promising prospects.Early geological work along the belt was done by A. W. Jolliffe who first recognized a number of great faults, the largest of which is the West Bay fault with a horizontal movement of more than 3 miles. In 1943, A. S. Dadson, following an examination of the Giant-Yellowknife property, advanced the hypothesis that Baker Creek valley was underlain by a series of major gold-bearing shear zones. Subsequent diamond drilling in 1944 bore out the correctness of this view and outlined the great ore-bearing shear zones that are now being developed and mined by Giant Yellowknife Gold Mines. Near the south boundary of the Giant property, the shear zones are cut off by the West Bay fault. This prompted Neil Campbell, District Geologist for the Consolidated Mining and Smelting Company, to make a detailed study of the geology along the West Bay fault in the hope of finding the faulted extension of the Giant shear-zone system on the west side of this fault. In this he was entirely successful. By careful geological mapping he matched several faulted diabase dykes on both sides of the fault and, knowing their dip, determined the horizontal and vertical components of movement along the fault. Subsequent •diamond drilling based on Campbell's work located the presumed correlative of the Giant shear-zone system on the Con-Rycon and Negus properties, where it has been named the Campbell zone or system. At the present time, all production at the Negus Mines property is coming from orebodies along the Campbell zone."

Jan 1, 1950

By B. Numerov

A numerical proceeding of corrections with respect to topography is worked out for places near the station and a graphical one for the remote parts of the terrain. The description is clear and very detailed. The numerical proceeding is very similar to that of the Eötvös and Schweydar methods which are in use already. In both methods the levelling is accomplished in certain circles and fixed azimuths around the station. While, in using the Eötvös method, the height differences are directly inserted into the final formulas with regard to the foot of the instrument and in case of accurate formulas derived by Schweydar the height differences are calculated with respect to the center of gravity of the attachment, Numerov introduces functions A and B, the heights, of the terrain and of the center of gravity, which are to be inserted into the formulas.

Jan 1, 1929

By Frances Hurd, Clark

Iv 1897, Roberts-Austen(l)$ found an arrest in the thermal curves of alloys of 60 per cent. copper and 40 per cent. zinc. This break occurred from 450° to 470° C. Shepherd, (2) working in 1904, was unable to detect any change in the direction of the thermal curve. In 1911, Carpenter and Edwards(3) confirmed the work of Roberts-Austen and called this a eutectoid transformation of beta to alpha plus gamma. Hudson') in 1914, showed that the beta constituent could be produced synthetically at temperatures below the transformation point. He believed the change in the beta was polymorphic in nature rather than a eutectoid. The work of Matsuda(32) in 1922 demonstrated this break by thermal analysis, microscopic investigations, dilatation, electrical resistance measurements, and a thermoelectric study. He believed the transformation to be continuous from 300° to 480° C., and comparable to the A 2 transformation in iron. Later, in 1924, Andrew and Hay, with electrical resistance measurements, confirmed Matsuda's work. Imai(28) showed the transformation to be progressive and therefore a function of the temperature rather than the time. He stated that it was neither a eutectoid nor an allotropic change of phase. Atomistically expressed, it was a change, not of atomic configuration, but of atomic energy of some kind; and again it was compared to the A 2 transformation in iron. Imai believed that his analyses by X-rays led to the same conclusion. In order to study this change, at 470'C., in homogeneous 60:40 brass, Homerberg and Williams «0> and Homerberg and Shaw(41) quenched their material in iced brine to obtain the beta solid solution and reheated at various temperatures. At 200° C., a change in the microstructure and physical properties occurred. A fine-grained structure, which they termed alpha and which had the appearance of a sorbitic steel, appeared, with an increase in the tensile strength to 82,750 lb. per sq. in., and a Brinell ball hardness of 240 with 3000 kg. load. At 470° C., the alpha

Jan 1, 1927

By R. V. Ramani, V. T. Burgos, J. A. McClay

Cost Systems Cost systems are organized methods of collecting, allocating, and accumulating resource utility expressed in terms of money. There are two major spheres of cost accumulation: financial accounting and cost accounting. Financial accounting deals primarily with historical costs and provides a means of measuring and recording cost events which have al¬ready taken place. While there are no legal requirements to control the methods of recording and reporting cost data in the United States, the procedures in use are guided by professional organizations such as the American Institute of Certified Public Accountants. The final pro¬ducts of financial accounting practices are the income statement and balance sheet which describe the financial status of the organization under study. Cost or managerial accounting is an expansion of financial ac¬counting procedures, providing more detailed cost breakdowns on present operations with one objective being the projection of present costs into the future. The projection process tends to limit the accuracy of the information; however, to management and project justification per¬sonnel, data on future operations tends to be of greater value. The basic principle behind cost accounting is the cost cycle. As products are developed from raw materials, the value of the work-in¬process increases due to the cost input of the various fabricating ele¬ments. Thus, from the basic input elements of facilities, labor, and raw materials, costs are added to each unit of production as a function of the work performed on that unit.

Jan 1, 1975

By R. P. McLaughlin

Discussion of the paper of R. P. McLaughlin, presented at the San Francisco meeting, September, 1915, and printed in Bulletin 'No. 108, December, 1915, pp. 2313 to 2319. M. E. LOMBARDI, Berkeley, Cal.-Mr. Bell, I would ask you to state before the meeting what you said to me the other day, about the final recovery of oil from oil sands that have become inundated with water. A. F. L. BELL, San. Francisco, Cal: In stating my opinion, I give it with certain qualifications. In the Kern field, and possibly in some others, I think we will eventually get all the oil out, whether the water comes in or not, since it is peculiarly constructed, being in the form of a partial dome. In 1909, while I was field manager of the Associated Oil Co., I installed some large air compressors to handle the water. At that time the oil had migrated to the higher and more shallow portions of the field, because the water had inundated the deeper sections. The result was that the shallow districts within the center of the dome were in many, cases producing as much or more oil per well than the deeper wells. And in the inundated sections the water had slowly spread over large areas, so that nothing but water was pumped from them. Under these conditions, we decided to pump the wet. well with air, and installed four 2,000-cu. ft. compressors. The air was compressed and forced into the wet wells at, about 250 lb. pressure. Shortly the inundated district that had produced almost all water and only about 150 bbl. of oil a day increased its production to over 2,000 bbl. of oil per day. It was not-long before, we noticed that the production of the shallow territory was falling off to such an extent that in many cases the wells were abandoned; at the same time the area of the water-inundated district was greatly reduced, showing that when the water pressure was reduced the oil migrated back to the lower depth. The wells which at first had had the air jets put into them finally produced so much oil that we had to take the 'air jets out and return to the use of the beam pump, because it is not commercially feasible to pump, an oil of 14° gravity with air. To handle such oil profitably by air, it must carry with it 50 to 90 per cent. of water. The results have led me to believe that oil monoclines, where there is a gradual rise to a certain point, or in plunging anticlines, even though water gets into oil sands, eventually we get the larger percentage of the oil. However, the man with a small acreage in the deeper sections may find some morning that his oil has gone, another man in some higher portion of the district having gotten it.

Jan 12, 1915

By Innocent John Arinze, Chidubem Okwudiri Emedo

This contribution presents the first multi-scale geophysical investigation conducted in the Abakaliki and Obubra mining districts (AOMD), southeastern Nigeria, for the exploration of shallowly emplaced (< 50 m) massive sulfide and barite mineral deposits. Raw airborne magnetic data covering the AOMD was acquired and subjected to diverse enhancement routines to facilitate the identification of areas of subtle magnetic anomalies for subsequent ground truthing. The mineralization is mainly made up of galena, sphalerite, and barite. The contrasting physical properties between these minerals and their host rocks make resistivity, induced polarization (IP), spontaneous potential (SP), and magnetic methods ideal to study and delineate the mineralization and possibly locate the ore bodies. Wenner DC resistivity and IP data acquired along the same parallel traverses are inverted using Res2dinv to produce 2D tomography models of resistivity and chargeability. The resistivity and IP models were successful in delineating zones of sulfide and barite mineralization. The ground SP data collected along the same traverses as the resistivity and IP data were interpreted as line graphs. The 1D SP models show a number of central negative anomalies that could be related to sulfide mineralization. These anomalies show fair-to-good spatial continuity and are in close agreement with the result obtained in the resistivity and chargeability model. This study suggests the presence of exploitable mineral deposits in the AOMD and demonstrates the superior interpretative ability of combined geophysical methods over a single geophysical approach.

Oct 20, 2020

By J. J. Shields

With the increased use of mechanized equipment in mining bituminous coal, production panels are mined out rapidly. To keep current with the rapid completion of production panels, development work must be speeded up also. Although the same type of equipment usually is employed in development as in production places in the same mine, past output per man for development usually was less than from production panels. A study of development practices in 14 mines reveals a tendency toward equalization of the output per man between development and production.

Jan 1, 1957

Much of the theory upon which the Sublevel Caving (SLC) method is based was developed in Scandinavia many years ago. It was based mainly on æbinÆ theory and æellipsoid of drawÆ configurations derived from sandbox models. In many cases, classical SLC layouts influenced by these early theories obtained relatively poor results. Early dilution entry, low tonnage factors and low recoveries were commonly experienced. SLC soon gained the reputation of being a high dilution, low recovery and development intensive method. This led to SLC falling into disfavour generally, other than as a pillar reclamation method used at the end of the life of mines. More recently a number of mines, notably those in Australia, have adopted SLC as a primary extraction method and have achieved good recovery results. The reason for the better results is believed to be an outcome of modifications in some of the basic design parameters and operational procedures. This has led to questions being raised regarding the original æbin theoryÆ assumptions and classical SLC layout designs. It is clear that the fragmentation and flow characteristics occurring in a choke blast situation (compaction of waste, variable size and shape of fragmentation throughout the ring) conflicts significantly with the assumptions of regular loose flow of uniform, fine grained, material in a bin. Interactive versus independent draw conditions can also materially effect the outcome of a SLC operation. The good results obtained more recently can only be explained by using ænewÆ models of behaviour, which have to a large extent been borrowed from block caving. If these models are correct, they point to a number of design and operational changes that can be applied to improve the effectiveness of SLC. This paper discusses the factors that may not have been fully considered in early SLC design and modelling. It emphasises the importance of delayed dilution entry as a primary objective of sound SLC design and provides a basis for efficient SLC design and operation.

Jan 1, 2000

By M I. Pownceby, N A. S Webster, J Manuel, N Ware

The properties of iron ore sinter – commonly defined by measures of tumble strength, reduction degradation and reducibility – have a major impact on blast furnace performance. These properties are largely influenced by raw material properties, in particular the bulk ore composition. Despite this importance, there is a lack of quantitative data on the impact of ore chemical composition on iron ore sintering. This is surprising since the levels of Fe, SiO2, Al2O3, P, MgO and other elements, together with the nature of the minerals in the fine ore, play a major role in determining the abundance and type of high-temperature bonding phases that form during sintering. It is the abundance and nature of the high-temperature bonding phase(s) that directly influences sinter quality. This study combines in situ diffraction experiments in model sinter systems with laboratory-based compact sinter tests using natural ores to examine the links between iron ore composition and sintering temperature and their effects on standard metallurgical sinter quality test methods. Results help to establish the critical compositional and thermal parameters that control the bonding phase chemistry, which in turn influences the physical characteristics of the sinter matrix. This information should enable operators to predict optimum sinter operating conditions based on the initial chemistry and mineralogy of the iron ore fines and recognise the chemical modifications to the original iron ore fines required to produce high-quality iron ore sinter.CITATION:Pownceby, M I, Webster, N A S, Manuel, J and Ware, N, 2015. Iron ore geometallurgy – examining the influence of ore composition on sinter phase mineralogy and sinter strength, in Proceedings Iron Ore 2015, pp 579–586 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Jul 13, 2015

By Stein Tore Johansen

Some ferro-silicon furnaces have heat-recovery equipment. Here, the recovery of electric energy from the off-gases can be increased by increasing the off-gas temperature. This is easily done by reducing the amount of air which usually is mixed into the?off?gas to cool the gas mixture. If the off-gas becomes too hot problems with severe fouling or clogging of the gas channels close to the furnace is observed. The result is irregular stops to clean the off-gas channels. The paper focuses on the nature of the clogging phenomena and some of the ways to avoid clogging. A detailed experimental study was carried out at the Elkem Thamshavn Plant. Theoretical studies were performed to understand the particle deposition, turbulent multiphase fluid flow and off gas combustion in the off-gas channels. The study has resulted in reduced clogging.

Jan 1, 1992

By R. T. Langland

The U.S. Bureau of Mines has conducted underground tests and computer analyses to study coal mine roof behavior. Southern Ohio Coal Company provided test sites it) their Heigs mines located near Athens, Ohio. Testing apparatus was adapted for monitoring roof behavior at the face of mining from a remote surface location. Finite element analyses were applied to study the structural conditions present. Test sites were located at three different intersections of entries and crosscuts of the room-and-pillar mine. Electrical read-out instruments were used to record roof bolt loads, roof sag, and roof-floor convergence. They were installed during the roof bolting cycle of a conventional mining section and data was recorded for several months. Normal mining operations continued throughout the test period with minimal interruptions due to the installation and monitoring of the instruments. A computerized data acquisition system, partly underground, partly on surface, permitted continuous monitoring of data and its retrieval, display, manipulation, and storage. The finite element code used to model the test sites accounted for three-dimensional geometry, nonlinear material behavior, and the mining excavation and bolt installation sequences. Results of the test are highly variable. Comparable values between test and analysis results were obtained by applying statistical averaging of. roof test data. Results of the analyses indicate that bolts have a lesser effect on the gross behavior of mine roofs than has been indicated and that bolt load changes are strongly influenced by mining excavation sequence, bolt-placement sequence, and face distance

Jan 1, 1977