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By Mark Rybak

On Aug. 31, 2006, Tropical Storm Ernesto hit the city of Richmond, VA. The Battery Park area was hit particularly hard, as flooding forced an evacuation of the area. A large sinkhole collapsed a sewer line in the Battery Park area, blocking the pipe and causing more serious flooding. This article describes the fast track design, bidding and construction of an emergency tunnel to bypass the collapsed sewer. Innovative value engineering, tunneling and shaft-sinking methods and final lining design all contributed to the success of this project. The storm inundated Richmond, VA with up to 305 mm (12 in.) of rain that, in some areas, caused widespread flooding and damage. One of the hardest hit areas of Richmond was Battery Park. A major trunk sewer in the Battery Park area collapsed and caused local combined sewer and stormwater flooding. The collapsed sewer was a 2.4-m x 76-mm (8-ft- x 3-in.-) wide by 2.7-m- x 152-mm- (9-ft- x 6 in.-) high arch sewer that was constructed in the 1920s and later filled over with municipal solid waste and a soil fill cap to cur-rent elevations. A sinkhole was created in the area of collapse approximately 18 m (60 ft ) deep and 31 m (100 ft) in diameter. This caused the existing arch sewer to become blocked. As a result of this blockage, contaminated floodwaters reached depths in low-lying areas in excess of 8 m (25 ft).

Jan 1, 2008

Theories of ore genesis. have both practical and philosophical application-practical in that they influence our search for new ore bodies; philosophical in that they provide a test for our theories of petrogenesis-and our ingenuity.For example, the theory of granitization requires an explanation of ore genesis compatible with the general concepts of granitization.Our understanding of some processes of ore formation, such as supergene enrichment, or the formation of residual lateritic iron ores, is so complete as to permit of nq controversy.For other ores, like the oolitic iron ores of England and France, and elsewhere, or the segregations of chromite or ilmenite in basic igneous rocks, the broad principles are generally agreed on; dispute is limited to details of process.But for a wide range of ore deposits there is no such agreement. Completely incompatible hypotheses are advanced to explain' identical facts, and we have difficulty in finding new facts or criteria that will distinguish unambiguously between them.In thinking about such ores, a co:n;venient starting point is provided by Schneiderhohn's (1953) fourfold division of ore deposits:1. The secondary hydrothermal ore deposits occurring in Mesozoic-Neozoic cover strata of Europe.2. The "regenerated" younger ore deposits in Alpine type mountain chains.3. Post-Cambrian primary hydrothermal ore deposits.4. Ore deposits of the PreCambrian shields.To these we may add a fifth group:5. Stratigraphically controlled sulphide deposits.

Jan 1, 1956

By Brett Zernich, Michael Krulc, Brett Robinson

This paper provides an account of the efforts undertaken to construct the Northeast Interceptor Sewer (NEIS) project, which is a portion of a much larger program in Los Angeles, California to upgrade the city’s wastewater facilities. The project consisted of a number of elements, including both soft ground and rock slurry wall shafts, drilled shafts, soft ground EPBM mining, rock TBM mining, large diameter pipe placement, and underground structure construction. The need to complete the project under strict schedule constraints, in addition to the challenges of underground construction in congested urban areas, necessitated the work be undertaken with the proper balance of state of the art equipment, and thoughtful planning. The paper will detail the means, methods, and equipment used on the project, as well as discuss several of the unforeseen conditions encountered during construction.

Jan 1, 2005

By Xuchen Fan, Chenyang Zhou, Yuemin Zhao, Liang Dong, Chenlong Duan

A gas–solid fluidized bed using magnetite particles is an effective methodology for coal beneficiation in the field of dry coal cleaning. Broadening the size range of magnetite used in the bed decreases medium preparation cost. In this study, a tapered fluidized bed was used to investigate a magnetite particle size range of −0.5 + 0.074 mm. The results showed that a tapered fluidized bed effectively strengthens mixing of magnetite with a wide size range (−0.5 + 0.074 mm). The results of beneficiation experiments indicated that with increasing tapered angle, separation efficiency increased and then decreased. The highest separation efficiency was obtained at a tapered angle of 10°. The optimal results showed that the ash content of the concentrate decreased from 31.82% to 12.33% with a probable error of 0.11, which indicated that a tapered fluidized bed was efficient to improve fine coal beneficiation performance.

J. H. Lord (Geological Survey of Western Australia): During the last few days in Kalgoorlie here we have heard on various occasions of the great job the mining engineers have done persisting against rising costs and increasing salaries without a rise in the price of gold. I think it has been somewhat overlooked that it has been difficult to find additional ore as well. I consider that geologists also should be commended on their action in persisting to search for more orebodies. This goes on in any mining community, but in Kalgoorlie in particular, I believe, over the last few years that it has been more difficult all the time to find additional orebodies and the Companies are calling for higher grades to offset the economic condition. I feel that this paper by Mr. Finucane shows that the geologists have persevered on an idea and discovered that they can find additional orebodies in the calc schist where previously it was thought that these did not occur. This has added many tons to the ore reserves, and although it is not very significant at the moment, the significance will probably improve as more work is done.The whole thing has shown us the importance of economic geology. Mr Finucane has had many years of experience here and he has given us a very able exposition of the economics of ore finding, and there are not many questions that one could pose to him, because most of the information he presented is obviously fact borne out by drilling, underground development and lining up the ore channels. He did briefly touch on ore shoots-the Oroya shoot and several others. It would be very good if we could, and I feel sure...

Jan 1, 1965

By E. Sharifi

Advanced Process Control (APC) has been one of the most beneficial tools in the past decades available to minerals processing industry. Low capital cost together with significant improvements in process optimization have made APC an attractive investment option for nearly all mineral processing units. During economic downturns, importance of process optimization becomes even more relevant as metal producers tend to target de-bottlenecking and process efficiency improvements rather than large-scale capacity upgrades. APC project clearly has a lot of potential to improve process performance but there are also some pitfalls to be identified and avoided in order to achieve a desired outcome. Above all, APC project implementation is collaboration between the system vendor and user. Targets for the optimization must be agreed together with the customer and process performance must be defined before and after the optimization project. Most importantly, performance of the process must be monitored on a continuous basis during and after the project and potentially improved further. This paper discusses Outotec’s experiences from various concentrator optimization projects. Some examples are discussed in more details; however, the main target is to present general guidelines enabling a successful APC project implementation.

Jan 1, 2014

By Wayne Burmeister, Danie Benade, Louis Meyer, Hugo Joubert

What is not measured cannot be managed. This is true of most things, including a furnace lining. This paper describes a Lining Management System used for this purpose. It provides the operations staff with a management tool to predict long term lining life and acts as a process optimisation tool. It alarms and records upset furnace conditions. Outputs from the system are described as presented through a specially developed software package and interface. It includes vertical and horizontal furnace sections showing estimated isotherms through the lining as well as the furnace bath. It also shows calculated heat flux values, estimated lining wear and the freeze layer profile. A novel three-dimensional display is described which provides the operator with a big picture view of the furnace crucible profile under real time operating conditions. The powerful trending facility for analysing both measured and calculated values is discussed. The required instrumentation hardware as well as the installation thereof is described, with special reference to an electrically insulating thermocouple socket design. Finally feedback is provided on the first year?s performance of the system installed on an open ferrochrome furnace at Assmang Chrome, Machadodorp, South Africa.

Jan 1, 2007

By G. M. Kintz

In safety work a study of past accidents is of value in determining means of reducing future accidents of the same character. This is particularly true with reference to coal-mine explosions. Data from publications of the United States Bureau of Mines and from published reports of the State inspector of coal mines of Colorado are presented in this circular in the belief that they will be of value to operators by indicating methods of preventing future coal-mine explosions. The tables included are complete only with regard to major disasters. The Bureau of Mines considers as a major disaster one in which five 'or more men are killed. However, this circular also includes a considerable number of minor disasters, Various explosions in the coal mines of Colorado from 1883 to 1932, inclusive, are listed with information available as to their probable cause, number of men killed and measures which, if they had been in use at that time, might have prevented them. John McNeil, first Colorado State coal-mine inspector, on page 43 of his first report for the period ended July 31, 1884, made the following recommendations for the prevention of explosions in the coal industry: True causes could be traced either to insufficient ventilation, carelessness and lack of rigid discipline in carrying on energetic ventilation and other precautions needed to be enforced in a mine giving off explosive gases. *** When any quantity of fine coal dust is observed in an entry, air course, or room it should be made damp and be removed from the mine, and thus beep every place as free from dust as possible. *** A system of bratticing close up to the face of each and every place in the mine from crosscut last made (whether gas should just then show its presence or not) which should not be more than 50 or 75 feet according to the nature of the mine.

Jan 1, 1933

By R. E. Wilmot

This paper is based on the experiences, over many years, of numerous authors in the South African mining industry and of the hot dip galvanizing process and its application as a corrosion protection system. The paper sets out the extensive development, financial resources and stringent operating requirements of the South African mining industry. After many years of research and operational experiences, hot dip galvanizing and, when necessary, duplex systems, have been found to meet the demanding requirements of this particular industry. The paper sets out the requirements from the standpoint of corrosion criteria and is followed with a case where the corrosion protection properties of hot dip galvanizing are demonstrated. This case history traces the early investigation of the expected corrosive conditions in a new mining operation and concludes with two follow-up visits to the mine in order to examine actual performance of the corrosion protection system after ten years in service.

Jan 1, 2007

By J. Bruce Clemmer

In the experimental concentration of Vermont talc-magnesite ores, talc concentrates and tailings rich in magnesite were obtained. On account of the possible market value of the magnesite, the tailings are given consideration' in this report along with the talc. After some comments about the talc industry, the magnesite that accrued as tailings will be considered. Then the flotation results will follow.

Jan 1, 1936

By Abouzar Vakili

Longwall Top Coal Caving (LTCC), as the most attractive method for thick coal seams, has been suffering from insufficient geomechanical understanding for the past few years. Cavability without doubt is the most critical geomechanical issue associated with the top coal caving method. A discontinuum method has been used for comprehensive modeling of LTCC operation by using the Universal Distinct Element Code (UDEC). In addition Particle Flow Code (PFC) and Phase2 were used as support for the caving mechanics analysis. Although the previous researches of gravity flow in caving operations neglected the effect of continuous span expansion, it has been observed in this study that face advancement has a great impact on roof symmetrical behavior. The amount of symmetry fluctuates between different face distances. Horizontal displacement seems to be the best indication for roof symmetrical evaluations. Two critical caving conditions have been modeled and parameters such as horizontal displacement, caving angle and recovery rate have been compared thoroughly. Results show that unsymmetrical behavior on the roof is closely related to face stability.

Jan 1, 2007

By James Tarr, Matthew Eichler, Brent Tardif

ANFO was being used as one of the blasting agents on a construction site in New England. Groundwater was encountered in numerous blast holes. The blasting contractor was employing typical explosives loading procedures for wet conditions. An abutter to the project complained that blasting caused her well water to have an odd taste and smell. Through testing, it was determined that there were hydrocarbons and nitrates in the well water. Several days later a second neighbor complained of foul tasting water; again it was determined that hydrocarbons and nitrates were present.

Jan 1, 2003

By R. Boom, L. Holappa

In the present paper, microstructure changes of solid-state reduction of industrial chromite pellets and lumpy ore were investigated with SEM/EPMA. To simulate the reactions in the packed bed zone of the Submerged Arc Furnace (SAF), carbon monoxide was used as the reducing agent, with the presence of graphite in proximity to chromite. The experiments were carried out at 1500 °C. Scanning electron microscopy was used to observe and analyse the structure and composition changes of the chromite samples. It was found that reduction of lumpy ore generally took place slower than that of pellet. In all samples, chromite reduction proceeded faster in the outer part of the sample than in the centre part. The reaction mechanism is discussed on the basis of experimental results and earlier investigations. The possibilities to optimize the FeCr production process are also discussed.

Jan 1, 2007

By James H. Rowland

The Mine Improvement and New Emergency Response Act of 2006 (MINER ACT) established a Technical Study Panel (The Panel) to provide recommendations on the utilization of belt air and new technology that may be available for increasing the fire resistance properties of conveyor belt used in underground coal mines. The Panel Report recommended use of the Belt Evaluation Laboratory Test (BELT) as the method for testing and approval of flame resistant conveyor belts used in underground coal mines. The research conducted to establish the correlation of the BELT with large-scale belt fire flammability tests was done using 36- to 42-in wide conveyor belt. Due to today?s coal haulage capacity, the mining industry is using 72-in and wider conveyor belts. The National Institute for Occupational Safety and Health (NIOSH) conducted a study to determine if the BELT will also qualify wider belts as fire resistant for use in underground coal mines. This paper describes the results of recent experiments comparing results from using the BELT and the large-scale tests for six different belts.

Jan 1, 2010

By Kiseong Hyeong, Young-Tak Ko, Gee Soo Kong

"The benthic environmental impact experiment addresses environmental impacts at a specific site related to deep-sea mineral resource development. For such a purpose, since 2010 we have carried out essential environmental research at both the BIS and a preservation site. We have acquired several tens multi- or box core samples at 32 sites within the BIS especially between 2011 and 2013, aiming to examine the basic properties of surficial deep-sea sediment as the potential source for deep-water plumes.In this study, we present physical the properties such as water content, shear strength and also geochemical properties such as major elements, rare earth elements (REEs), heavy metal contents at the BIS. Such proxies vary distinctly according to the Facies association. The lithology of all core sediments in the BIS corresponds to both Association Ib (Unit I/Unit II) and Association IIIb (Unit I/Unit III) on the basis of the KORDI classification (KORDI, 2004); Unit I is watery mud and dark grayish brown (10YR4/2) to dark brown (10YR4/3). Unit II is highly bioturbated mud and brownish yellow (10YR6/6). Unit III is very dark brown (10YR3/2) to black (10YR2/1) mud. Physical properties of these sediment types show that Association Ib is distinct from Association IIIb. The vertical profile of water content changed more sharply in Association IIIb probably due to compaction; water contents varied from 230 to 300% in Association Ib and changed from 200 to 250% in Association IIIb. The vertical profiles of shear strength are also quite different between Associations; the profile curve in Association IIb is much more gentle due to bioturbation."

Sep 1, 2014

By P. Chaddock

The Thompson Mill has a capacity of 15,000 T ID of ore and produces two grades of nickel concentrate, copper concentrate and occasionally graphite concentrate. Up to July of 1985 we processed two distinct ore types: T-1 ore, averaging 2. 8% Ni and . 2% Cu and Pipe Open Pit ore, averaging . 8% Ni associated with peridotite and serpentine. Presently our ores from T-1 mine and Thompson Open Pit are of the same type and are processed together. (Figure 1)! n October, 1982, we decided to install an Outokumpu Courier 300 on-stream analyser on an initial 6 streams. The equipment was delivered to the mill on May 2, 1983 and the first analyses were generated by June 17th. The calibrations were 35% complete by the mid-July summer shutdown and were completed in the fall. 1. 2 Analyser Slurry Feed System:The key to successful on-stream analysis is delivery of the sample streams to the analyser.Our system uses pressure-thief sampling for collection. (Figure 2) Initially we used thief samplers modelled after the Outokumpu design, with turbulence bars upstream of the collection point. These units have been replaced with simple laterals as they have worn out. Our thief samplers are mounted vertically on pump discharges and we believe sufficient turbulence exists to ensure representative sampling.

Jan 1, 1987

By Russel Delmar

Construction of Ontario Power Generation?s 12.8-m diameter, 10.4-km long water diversion tunnel in Niagara Falls, Ontario, is underway. The tunnel is being excavated by means of a 14.44-m diameter open gripper Tunnel Boring Machine. The tunnel lining is constructed as a two-pass system with the initial lining consisting of rock bolts, mesh, steel channels or ribs, and shotcrete, and the final lining consisting of pre-stressed cast-in-place concrete with a waterproof membrane. This paper describes salient design and construction aspects as follows: ? Regional and Site Geology ? Tunnel Layout and Design ? TBM Tunnelling and Cast-in-place Concrete Lining Construction

Jan 1, 2008

On the Hauraki goldfields, within the limits of Cape Colville Peninsula, the Paheozoic rocks are confined to the district north of a line drawn from Mercury Bay on the east coast to Rocky Point on the shore of the Frith of Thames. South of Kennedy's Bay they are developed on the east coast only at Kuaotunu, at which place gold mining is carried on in sandstones and slates of this age. Between Tapu Creek and Coromandel there is, along and adjacent to the shore of the gulf, a very considerable development of PaJreozoic and in part of Trias rocks, and between the Tiki Stream and the northern end of Tokatea Hill, along the western slope of the main range, lies the special area of the Palreozoic or carboniferous rocks that have more particularly to be dealt with in this paper. The same formation has a large devolpment between Cabbage Bay and the northern slopes of Moehau, and appears to the water marge on both sides of this part of the peninsula.In this part they are of special interest as having, on the west spur of Moehau, a considerable variety of dyke rocks intruded into the sedimentaries, the interest in which is increased by the fact that these dykes theIllselves are of Palreozoic age and correspond to the dykes that are so' abundant in the Tokatea-Tiki area. It is this Tokatea-Tiki area as a goldfield, and its rocks as distinguished from later volcanic' products' on other parts 'of the peninsula...

Jan 1, 1903

By Peter J. Nicholson

Since the reintroduction of soil mixing to the United States over 10 years ago, the work installed by soil mixing technology has grown dramatically. From an annual turnover of less than ten million dollars per year the volume of soil mixing put in place has grown to an estimated $40 million per year in the year 2000. The majority of work done to date has involved walls, either for excavation support, permanent retaining structures or hydraulic cut-off walls. The other major use for soil mixing has been for mass stabilization of soils whether for isolation of contaminants or for retaining structures. This paper will discuss the uses of and costs of typical soil mix structures. BACKGROUND Soil mixing is defined as the in-situ combining of reagents, typically cement, with native soils, the purpose being to modify or improve the ground. This history of soil mixing covers only the use of cement slurry, aggregated with soil in-situ by mechanical mixing methods only. Soil mixing by use of high-pressure hydraulic means, also known as Jet Grouting, will not be discussed. In addition this will not cover ex-situ (above ground) mixing, or mixing dry reagents with soil. Only mixing applications for building, civil and heavy construction applications will be discussed, with only passing reference made to uses of soil mixing for environmental remediation work.

Jan 1, 2001

By Zwaan J, Kepa J

Ok Tedi mine has become one of the major copper producers in the world. In the process of becoming of age, it overcame the challenges of operating in a locality which is young in geological terms, experiences very high rainfall and has a topography which gives rise to frequent landslides. This paper discusses some of the geological, mine and geotechnical engin- eering aspects of the Mt Fubilan ore deposit.

Jan 1, 1991