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The object of this paper is not to describe any particular type of engine in close technical detail but rather to give a general picture of past and present practice in this important section of the industry. The subject involves the study of almost 600 years of coal mining history which has fluctuated from stagnation to extremely rapid progress.Up to the year 1300, coal was obtained from outcrops and exposed beds, but this easily worked source soon gave out, so by that time shafts had to be sunk to the coal seams, and coal mining proper commenced its career.These early shafts were very shallow, and winding equipment was not a matter for much concern. Raising coal was generally achieved by human labour, which was called "coal bearing." Coal was loaded into baskets. strapped to a man's back, and carried from the underground workings to the pit bottom. The unfortunate individual then climbed ladders to the top of the shaft, unloaded the basket, and descended the shaft for the next load. Men, women and even children, were employed as the mine expanded, and were generally bound to the colliery for life, performing daily work which would now be regarded as slavery. This primitive method of raising coal to the surface was slow, inefficient and highly dangerous, yet for want of a better method it continued until in 1602 it isrecorded as having been abolished in Wales, one of England's great coal districts. It was not until 100 years later, however, that it was abolished in the northern coalfields, and the colliers were freed forever from their dreadful life.WINDLASSThe first step towards winding coal was the introduction of the windlass. This was similar to the common windlass used over a well, and was operated by man power. The...

Jan 1, 1945

By Luke K. A

Pressure on production at New Zealand China Clays has led to the development of a dewatering control loop for fine halloysite china clay. The development was based on the analysis of data from the automation of plate and frame filter presses. The analysis of the data has led to process changes, and the ability to quickly solve dewatering problems. As a result of control in the dewatering circuit press times have reduced on average 117% and output has increased proportionally.

Jan 1, 1989

By K. Boakye

This paper presents the results of a review of historic blast design practices at the Dragon Products Company, LLC (Dragon) Quarry Operation, along with the results of two different blast design vibration monitoring programs. A blast pattern design modification was initiated to determine if production volume per shot could be increased and highwall instability could be decreased. A vibration monitoring program was undertaken to investigate peak particle velocity (PPV) and relate the data to the blastability of the jointed onsite rock mass, utilizing the relationship between PPV and dynamic stress and strain. The Dragon Quarry Operation has historically used a 6-in. diameter, 14-ft by 14-ft production blast pattern, with blast holes loaded manually using cartridge style explosive products. In 2011, Quarry Operations introduced a 6-in diameter, 16-ft by 16-ft production blasting pattern, using pre-mixed, truck-loaded, bulk emulsion/ammonium nitrate/fuel oil (ANFO) blends. This paper summarizes the results of the blast design modifications, the results of the vibration monitoring data, and describes how production blasting and excavation at the Dragon Quarry has benefited from such modifications.

Feb 27, 2013

By Aly M. Mohammad

The Howland Hook Terminal Facility located in Staten Island, New York is one of the most active container terminals in the Northeast United States. Due to the high capacity of the facility, the Port Authority of New York and New Jersey (PANYNJ) recently acquired the adjacent 37-acre Port Ivory Facility. Expansion of this Site facilitates the additional transfer of goods for rail transport, where formerly the facility was solely highway transport. Upon completion, the facility will have the ability to transfer containers directly to a freight rail line onsite by crossing from Howland Hook Site to the Port Ivory Site via a proposed bridge over Bridge Creek. The geology of the Port Ivory Site consists of shallow glacial deposits left by the leading edge of the last advance of the Wisconsin Glacier. Glacial and marine action over the millennia and the modifications of past construction combined to form a challenging site geologically. Prior to the PANYNJ acquiring the site, the Port Ivory Facility was occupied by Proctor and Gamble for nearly 100 years. Over the course of time, the site has had a variety of structures constructed and demolished at the site. The earliest structures were often supported on shallow foundations and the foundation types used progressed over the years transitioning from low capacity timber piles to various new pile types as they became available; such as Raymond tapered piles, steel piles with concrete cores, precast piles and cast in place foundations. Currently, we are designing 4-foot diameter high capacity drilled shafts to support a new bridge over Bridge Creek to connect the two sites. Drilled shafts proved to be a very economical solution from both a design and construction point of view to carry the axial load of the bridge of approximately 400 tons per shaft. The paper will present a historical evolution of the progress of deep foundation types used at the Port Ivory Site; from low capacity timber piles to high capacity large diameter drilled shafts. The paper will also present changes and modifications of geotechnical design criteria over time that affects the type of deep foundations used. For instance, utilizing new seismic design criteria requires selecting a deep foundation system that withstands seismic loading conditions and overcomes the effects of liquefaction.

Jan 1, 2004

By K. Lim, J. Sobil, L. Galarza Castillo, F. Tozlu

"For mining operations globally, the scale and criticality of the grinding mill drive has meant that selection of the correct mill drive technology is paramount. With so much depending on the successful implementation of the electrical drive system— safety operation, timely installation, availability, energy efficiency, minimum maintenance and extend its use as tool to assist during mill liner exchange—customers are justified in their scrutiny and slow adoption of new drive technology. From the first installation of low, fixed speed synchronous motors to the introduction of the current source and further voltage source variable frequency drive, innovations require long periods of time and mining customers willing to push the industry forward. In recent years, the variable frequency drive has been the stepping stone for a new generation of mill drive technology. In use for decades in other heavy industrial applications, the drives allow for system optimization in a myriad of ways. The most dramatic of changes is in the design of the motor. Where in the past motor design was bound by line frequency, today the designer can optimize machine size and, more importantly, eliminate the need entirely for the synchronous motor. Induction motor design has now progressed to the point where low speed operation is possible at efficiency levels nearing those of the synchronous design. Moreover, the simplicity of the squirrel cage design means that availability, reliability and spare part requirements are greatly improved. As the next step in the evolution of large pinion driven grinding mills, the low speed induction drive offers a new reliable and robust system to the market.IntroductionAs deposit grades continue to decline, new ways of processing ever greater concentrator throughputs have been required to maintain throughput efficient and profitable operations. Furthermore, the high risk nature of mining developments requires a constant search for safer, higher availability and more efficient equipment design. Limitation of downtime is a key factor in ensuring mining operations can be sustained through volatile market conditions. Often processing the entire mine throughput through just 1 or 2 lines, the crushing and grinding circuits are of particular criticality to the uptime and, thus, profitability of any mining operation."

Jan 1, 2016

By K. Liu

"In the present work, two-step heat treatments with preheating treatments at different temperatures (175, 250 and 330°C) as the first step followed by the peak precipitation treatment (375°C/48h) as the second step have been performed in Al-Mn-Mg 3004 alloys to study their effects on the formation of dispersoids and evolution of elevated-temperature strength and creep resistance. During the two-step heat treatments, the microhardness is gradually increasing with increasing time until to a plateau after 24 hours when first-treated at 250°C and 330°C while there is a minor decrease with time at 175°C. Results show that both the yield strength and creep resistance at 300°C reach the peak values after the two-step treatment of 250°C/24h+375°C/48h. The formation of dispersoids is greatly related to the type and size of pre-existing Mg2Si precipitated during the preheating treatments, in which that coarsened rod-like ß’-Mg2Si strongly promotes the nucleation of dispersoids while finer needle-like ß’’-Mg2Si has less influence. Under optimized two-step heat treatments and modified alloying elements, the yield strength at 300°C can reach as high as 97 MPa with the minimum creep rate of 2.2×10-9 s-1 at 300°C in Al-Mn-Mg 3004 alloys, enabling them as one promising candidate in lightweight aluminum alloys for elevated-temperature applications.INTRODUCTION Due to the rapid demand from weight-sensitive automotive and aerospace industrials for the light alloys, such as aluminum alloy on the elevated-temperature applications, Al-Mn 3xxx alloys has been developed to obtain the good properties at both room temperature (RT) and elevated temperature, in which the dispersoid-strengthening mechanism plays a significant role (Li & Arnberg, 2003; Li, Muggerud, Olsen & Furu, 2012; Liu & Chen, 2015, 2015). In our previous works (Liu & Chen, 2015, 2015; Liu, Ma & Chen, 2017), the yield strength and creep resistance at 300°C of Al-Mn-Mg 3004 alloy were further improved by modifying the alloying elements, such as Fe and Mo, to optimize the characters of dispersoids, including the size, distribution and the dispersoids free zone (DFZ). For instance, Mo was introduced in aluminum alloy to further improve the volume fraction of dispersoids and reduce the area of DFZ, leading to increasing on both the strength and creep resistance at 300°C (Liu, Ma & Chen, 2017). On the other hand, the mechanical properties became worse at higher Fe content due to its consumption more Mn to form Al6(MnFe) intermetallics, resulting in less available soluted Mn for the precipitation of dispersoids (Liu & Chen, 2015). Therefore, optimizing the characters of dispersoids is always the key to improve the elevated-temperature properties of dispersoid-strengthened aluminum alloys for elevated-temperature applications."

Jan 1, 2017

By Patty Simpson, Sarah Benson

In an effort to improve consistency across the nuclear industry, over the past 10 years the Canadian Standards Association has developed a series of standards related to environmental management at Class 1 nuclear facilities and uranium mines and mills. Canadian uranium mines have been required by the Canadian Nuclear Safety Commission to align their existing monitoring programs with these standards. Orano’s McClean Lake Operation’s monitoring program, which was originally presented in the Environmental Impact Statement in 1991, has evolved through regulatory change, new scientific understanding, additional projects, and experience into a comprehensive set of monitoring requirements for effluent, groundwater, air emissions, and the receiving environment. The exercise of aligning the existing practices with the standards provided an opportunity to review and rationalize the entire program. To document the process the original “Environmental Monitoring Program Design Document” was restructured and developed as both a repository for historical information and monitoring rationalization, and also to be a living document describing on-going studies and supplementary work that are outside of the regular environmental monitoring program and may justify future changes to the program.

Jan 1, 2020

By Z. R. Llanos, W. G. Deering

Gulf Chemical and Metallurgical Corporation (GCMC) has been operating facility for treatment of spent catalysts in Freeport, Texas since 1974. Recently, GCMC expanded its operations with the addition of an electric furnace for the production of fused alumina and mixed alloys. GCMC and its affiliate Sadaci, started up a new pre-treatment facility in Ghent, Belgium in 1998. GCMC is also part owner of Bear Metallurgical Corporation, a major producer of ferroalloys in the United States. This paper reviews the processes at these facilities. Changes in the management of hydrotreating and hydrorefining spent catalysts are discussed in light of recently issued federal regulations that made the majority of spent catalysts a listed hazardous waste.

Jan 1, 2000

By Benoît Waquet

In a context of scarce mineral resources, coupled with an increasing global demand in metals due to the exponential growth of newly industrialized countries, the mining industry will inevitably have to deal with tomorrow?s resources: underwater deposits. Three types of offshore deposits are known to date: polymetallic nodules, cobalt-rich crusts and hydrothermal sulphides. The latter, regarding the political-economic context, is now considered most likely to be exploited in a near future. Operating a mine critically requires accurate knowledge on geotechnical properties of the ore. A question is thus to be asked: Is there a particular spatial organization of geotechnical properties in a hydrothermal sulfide mound? In the present study, geotechnical properties have been measured for 29 sulfide samples of known origin, completed by 14 measurements on Western Pacific specimens from Yamazaki et al. (1990) and Yamazaki and Park (2003). From these geotechnical data on 43 sulfide samples, we can provide some answers to this question above, crucial for future exploitation of underwater mines.

Jan 1, 2010

By S. Makni, S. Koppalkar, A. Bouajila

This paper reviews briefly the gravity recovery involving conventional gravity separators and centrifugal gravity separators. The advantages of semi-continuous gravity separators will be discussed. Techniques for upgrading the gravity concentrates will be addressed briefly. The research efforts in optimizing semi-continuous gravity separators will be recalled. Innovative gravity circuit for eliminating or minimizing the use of complex processing schemes will be reviewed. On-going gold gravity research at COREM has revealed that gold particle shape transformation is the main factor explaining the lower recoveries of the plant units. Efforts to devise possible remedies for improving gravity recovery at plant will be discussed.

Jan 1, 2011

By S. Makni, S. Koppalkar, A. Bouajila

ABSTRACT This paper briefly reviews the gravity recovery between conventional and centrifugal gravity separators. The advantages of semicontinuous gravity separators will be discussed, as will techniques for upgrading the gravity concentrates. The research efforts in optimizing semicontinuous gravity separators will be recalled. An innovative gravity circuit for eliminating or minimizing the use of complex processing schemes will be reviewed. Ongoing gold gravity research has revealed that gold particle shape transformation is one of the main factors explaining the lower recoveries of the plant units. Efforts to devise possible remedies for improving plant gravity recovery will be discussed.

Jan 1, 2013

By S. D. Tolgyesi

Kidd Creek Background ? Located in Northern Ontario, Canada ? Underground base metal mine ? Operating since 1966 ? Total of 125Mt mined to date (2.43% Cu, 6.60% Zn) ? Current plan at 2.4Mt/Y (6575t/D) Current Practices ? Evaluating stope margins to ensure that value is added ? Scheduling sulphide and Cu stringer ore to limit oxidation in passes ? Scheduling to maintain uniform grades to concentrator ? (SOPs highlight problem stopes on mine plans, and limit blast sizes in those stopes which may contain sulphides prone to oxidation) ? Scheduling high-Pb stopes to avoid spikes to concentrator ? Providing weekly, monthly and long-term forecasts ? Reconciling mine and mill production ? Underground grade and dilution estimates by mine supervision ? Terminate mucking when grade becomes sub-economic ? Laser cavity surveys to provide feedback and improve Designs Cut-off Grades ? Ore value is obtained from copper, zinc and silver ? Ore outlines at 2% copper equivalent used to guide stope planning; sulphide outlines obtained from contacts while copper stringer outlines drawn from block model (kriged) ? Datamine block model and CADD software used to evaluate alternative stope shapes ? Stopes classified as waste, incremental, or full-cost based on margin calculations for each stope ? Incremental ore may be mined if it does not displace fullcost Ore Conclusions ? Grade control remains an important function for optimizing the ore extraction at Kidd ? The scope of the function has changed to a scheduling focus ? A change in grade control practices over time has not led to significant changes in concentrator feed ? The lead and iron sulphide content of the ore display upwards trends and may require more attention in the future ? The key function of field observations has shifted to flagging exceptions and terminate mucking at grade cut-off

May 1, 2003

By T Cutts

Since 1989 Kalgoorlie Consolidated Gold Mines has managed the Kalgoorlie gold operations of joint venture partners Normandy Mining Ltd and Homestake Gold of Australia Ltd. Current production from the Fimiston Open Pit is approximately 650 000 ounces per annum. The mine incorporates a multitude of narrow shear hosted, subvertical lodes, predominantly within Golden Mile Dolerite. Traditionally KCGM has used blasthole based grade control in the Fimiston pits. A single sample is taken from vertical production blastholes, drilled on ten metre benches. This process was improved with the addition of infill drilling along blasthole rows to provide additional samples across strike. However the limitations of adequately defining subvertical mineralised structures with vertical blastholes remain. In 1997 the first of two trial areas were drilled with close spaced, inclined Reverse Circulation (RC) drilling. These tests indicated that RC based grade control had the potential to provide significant advantages. These include:improved delineation of mineralised structures, particularly across strike; reliable short-term mine schedules based on the advance data available from drilling over three benches; and the angled RC drilling is capable of providing samples of near stope and stope fill material which often remains unsampled by blasthole drills due to the safety constraints around unstable underground openings. Based on the success of this initial work RC based grade control was gradually implemented across production areas commencing September 1998. Some of the many challenges faced include:development of effective procedures and systems for the planning, logging, interpretation and modelling of the RC data; obtaining adequate drill coverage due to mine scheduling constraints and restricted access around underground openings; requirement for integrated systems to handle either blast hole or RC data; and development of effective methods to evaluate the performance of RC grade control. RC based grade control is delivering significantly improved lode definition, grade estimation and subsequent ore classification.

Jan 1, 2000

By Wolfgang Van Hooff

Encouraged by a strongly growing and evolving market for granulated products, Paul Wurth continuously improves its granulation and dewatering technologies to provide customers with state of the art installations. Continuously developed know-how about the granulation process of iron blast furnace slag enabled application to non-ferrous materials such as Ni-Slag, Pb-Slag, Blister Copper, Cu-Matte and even TiO2-Slag, which rank among the most difficult materials to granulate. This paper identifies how critical objectives in granulation and dewatering technologies applied to different molten materials with respect to various product quality objectives can be addressed. The differences between hot and cold water granulation systems are explained, including the step from cold runner to granulation water tank. Development of a flow and pressure controlled blowing box is the latest step to optimize the granulation process in order to meet the latest standards in terms of quality, power consumption and environmental protection.

Jan 1, 2006

By Michael Perlow

Helical screw piles in use since 1838 are routinely used for energy, transportation, municipal, industrial, marine and coastal infrastructure as well as for excavation support, environmental remediation, and foundation repair. They are especially well suited for work in constrained areas, renovations and structure retrofits. Helical pile design procedures over the past 10 years have gone through a remarkable evolution with the establishment of the 2007 AC358 Helical Pile Acceptance Criteria and inclusion of helical screw piles in the 2009 International Building Code (IBC). New 2009 IBC building code requirements and AC358 Acceptance Criteria are presented along with advances in helical pile design procedures, installation, QA/QC, and recommended load test verification criteria. Use of helical smart piles to validate helical pile design and verification of ultimate pile capacity is highlighted.

Jan 1, 2011

By F Hungerford

"In-seam drilling has been undertaken for the past 30 years for gas drainage to reduce the risk ofoutburst and lower the concentrations of seam gas in the underground ventilation. The drillingpractices have reflected the standards of the times and have evolved with the development oftechnology and equipment and the needs to provide a safe environment underground. Earlypractice was to adapt equipment from other fields, but with changing emphasis, research anddevelopment by the coal industry has created specifi c equipment, technology and practices toaccurately place in-seam boreholes to provide efficient and effective gas drainage."

Jun 1, 2012

By C R. Sundberg

Despite nearly a half-century of continuous production, the low-grade iron ore (taconite) deposits of North America remain economically competitive sources of raw materials for the domestic steel industry. The continued viability of these mature integrated mining-concentrationagglomeration complexes requires highly efficient utilisation of assets, especially the mineral resource. At Cleveland-CliffsÆ five North American managed operations, enhanced ore characterisation techniques are playing a critical role in their continued success. Due to the low-grade nature and complex mineralogical composition of these deposits, ore characterisation cannot solely rely on assay grades. Historically, taconite ore characterisation has augmented assay grades with bench-scale concentration tests to quantify recoverable mineral. The economic necessity for improvements in mill efficiencies and final product quality has mandated significantly greater knowledge of ore-related impacts. Cliffs Technology Center has met this challenge by developing a variety of novel iron ore characterisation techniques. The applications developed include both in situ and laboratory procedures, plus unconventional data integration methods uniquely suited for these deposits. This paper details the evolution of these novel ore characterisation techniques and their application to each phase of the operation: mining-concentrating-and pelletising. The improved ore characterisation techniques have contributed to successes at individual Cleveland-Cliffs managed operations including mineral recoveries exceeding 95 per cent and productivity increases exceeding ten per cent while consistently achieving customer product quality objectives.

Jan 1, 2002

By X. Cao, X. -G. Chen, K. Liu

Due to the detrimental effect of platelet iron-rich intermetallics on mechanical properties (particularly ductility) in cast alloys, it has been essential to transform these phases into Chinese script morphology. In the present work, the effects of Mn and/or Si addition and cooling rate on the phase transformation of the iron-rich intermetallics in 206 cast alloys with different Fe contents ranging from 0.15 % to 0.5 % were systematically investigated. The results obtained showed that platelet ß-Fe and Al3(FeMn), Chinese script a-Fe, Alm(FeMn) and Al6(FeMn) can be observed in the 206 cast alloys, depending on the Fe, Mn and Si contents as well as the cooling rate. It was found that the addition of either Mn or Si favors the formation of Chinese script iron-rich intermetallics but inhibits the precipitation of the platelet phases. In addition, the combined addition of both Mn and Si has a synergistic effect on the phase transformation. Furthermore, there exists a critical cooling rate to effectively suppress the formation of platelet iron-rich intermetallics for a given alloy. The threshold cooling rate decreases with increasing Fe, Mn and Si contents. Casting process maps are established to correlate the intermetallics precipitated with alloy chemistry and cooling rate for 206 cast alloys containing various Fe levels.

Jan 1, 2014

By Pierre Dosmond

In ore mining technology, the loading and hauling operations are undoubtedly the area where the most spectacular progress has been made during the last twenty years. I shall draw some examples from the Eastern France iron ore mines which I how well and whose production of 62 million tons for 1962 and 1963 constitute a worthwhile experience worldwide. The iron ore deposits of Lorraine are of sedimentary origin. They contain many mineralized horizons with workable seams situated from 330 to 830 ft. in depth. The dip of these seams is generally less than six percent. Their thickness varies from 6 to 23 ft. All seams are not workable throughout the whole area of occurrence, but in some mines there are five mineable seams in the same vertical section, with from 5 to 20 ft. of barren ground intervening between them. The iron content of the mineral varies from 28 to 36 percent. Specific gravity of the ore is 156 lb. per cu. ft. m place and 100 lb. per cu. ft. blasted. Reserves of iron ore in the Lorraine region are estimated at six billion tons with an iron content of more than 28 percent. These mines operate by means of rooms and pillars process, with pillar robbing; the final recovery is very good and averages 90 percent. Some years back, competition from richer, imported ores incited these mines to make constant efforts to increase their productivity and reduce mining costs, thus placing them in a leading position in mining technology, as evidenced by the dramatic evolution of their output per manshift (Figure No. 1).

Jan 1, 1970

By Arthur S. Dwight

THE last decade of the 19th century was a peculiarly interesting one in. the annals of American metallurgy, especially as concerns the lead and copper- smelting industries; and it may be interesting to review briefly one of the outstanding incidents of that period, the development of the mechanical roasting furnace. I shall not pretend, in these reminiscences, to give with absolute accuracy the sequence of events or dates, nor to present a complete history of the period, but shall seek merely to 'sketch a more or less impressionistic picture with some of the underlying facts and causes as the recollection comes back to me and then point out how the present-day practice grew out of those activities. My acquaintance with the developments in Montana was based on occasional visits and general collateral information, but in Colorado I lived through the episode and was of it.

Jan 1, 1921