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By Robert J. Clarke

Reflections on over ten years experience handling bituminous coal from railroad cars to ground storage and lake vessels. The arrangement of the facilities is described but the basic theme of the discussion is the experience gained and lessons learned from facility operation. The Great Lakes provide the maritime environment for the economical transport of vast quantities of raw materials from their source in the Upper Lakes (the Mesabi Range, for instance) to Lower Lake Ports. Lake Erie, because of its proximity to the steel centers , blossomed with the great ports that now line its southern shore - Toledo, Sandusky, Lorain, Cleveland, Huron, Ashtabula, Conneaut and Erie.

Jan 1, 1981

By William M. Greenslade

As the search for minerals leads to deeper mines the need to control water inflow into mine shafts and mine workings will grow. As shal¬lower more readily available minerals are exploited, ore bodies which were previously uneconomic be cause of their depth will now become attractive targets. In known mining districts new ore bodies are being discovered down dip of existing ones. In the west many metal deposits are being developed in rocks of the mountain front pediments, frequently covered by several hundred feet of saturated alluvium. Greater depth often means that workings are developed well below existing water tables, creating high hydrostatic heads adjacent to mine workings. The purpose of this paper is to review some of the methods available for determining if water control will be necessary and to present some of the techniques for locating water bearing zones and the amount of water to be expected. The paper will concentrate on problems associated with water control in mine shaft development, although many of the exploratory techniques are similar to those needed for assessing overall mine water inflow problems. A brief case history on water control problems in mine shafts in the Grants mineral belt of northwestern New Mexico is presented. Water control during shaft sinking presents some unique features. First, the problem is a relatively short term one, since water control is often necessary only while the shaft is being sunk. Control measures may be necessary only while the shaft is open into the water bearing zone and the lining installed and cemented. Secondly, limited working space within the shaft area presents difficulties in handling large amounts of water inflow. The presence of water in the shaft working area increases sinking time and the potential hazard to miners. Finally, there is the economics of shaft sinking. While the shaft is being sunk no ore is being produced and there is every incentive to minimize costs.

Jan 1, 1979

By W. Porter Place

The Trolleyphone was the first successful application of carrier current techniques to a DC power distribution system to provide voice communication between fixed points and moving locomotives and traveling cranes, This was a significant breakthrough because this not only in itself provided a useful new tool for industry, but the knowledge gained in the transmission of voice communication is paving the way for many other things, chiefly, remote control and indication systems which promise to have a far reaching effect during the upcoming age of automation. Once it has been established that we can communicate between men who operate machines, the next step will be to operate the machines themselves.

Jan 1, 1958

By H. Takamoto, M. Ichinose

"The basic objectives of mine roadways are to provide sufficient cross sections in order to meet the needs of accommodation of equipment, transport, personnel travel and ventilation. However, many roadways become damaged to the extent of needing maintenance, generally dinting, and in some cases requiring re-ripping. The damaging of a roadway is a result of several factors including geological properties of surrounding strata, method of roadway formation, support systems and so on. Among these factors, strata conditions play important effects on the stability of roadways and other mining activities. Weak rocks cause excessive roadway closures, and water softens some rocks and worsens the closure problem. In Indonesia, over 250 Mt of coal is now produced from almost surface mines. In the near future, some coal must be mined from underground. Unfortunately, the mechanical properties of coal measures rocks are not so good to open underground mines. In this paper, a scientific discussion on the effect of water on the stability of roadways is given on the basis of results obtained by means of in-situ investigation and laboratory tests both in Japan and Indonesia."

Jan 1, 2011

By A. Tarigan

The integration of the ESZ orebody and DOZ orebody resulted in a much larger footprint than the original DOZ Mine shape. The significant change in footprint geometry presented new cave front management challenges, specifically: longer undercut drifts. Using a constant blasting rate, more time is required to complete caving in each drift which ultimately influences the number of active faces at any point in time. The number of manageable active drifts is controlled by the planned square-meters of undercut blasting, lead/lag restrictions and other specific conditions such as the need to blast pre-charged explosives. In early 2008, an evaluation of the existing plan showed that significantly more active undercut drifts and longer cave fronts would occur in the next five years. Difficulties associated with the long cave fronts led to a decision to redesign the caving sequence. Several different boundary options based on operational, geotechnical and ore grade parameters were investigated. This paper describes the issues faced with long cave fronts, the constraints and requirements to effectively manage the caving sequence and the options considered to mitigate this situation.

Jan 1, 2010

By T. J. Durbin

At some surface and underground mines, control of ground-water inflow involves significant costs. These costs include the capital costs for installing a dewatering system, power and other costs to operate and maintain the system, and costs to treat and dispose of the water that is collected. To minimize these costs, design of a dewatering system utilizing wells has been formulated in terms of a nonlinear operations research problem using quadratic programming. Using this formulation, the locations, depths, pumping rates, and pumping schedules of wells are selected so as to minimize the total costs of the dewatering system.

Jan 1, 1993

By B. Cavender

Safety departments have traditionally been held responsible for the safety performance of their division or company. This approach leads to a lack of ownership of safety issues by the larger organization. An alternative paradigm is significantly more effective: the members of the work force (managers as well as workers) are fully responsible and accountable for safe production. The safety department is not extinct, however. Its role has changed, to focus on training, litigation, and external relationships such as community relations. This approach was implemented at BHP Copper's Superior mine and mill in Arizona. By obtaining the genuine commitment of the work force to accident-free production, the mill's MSHA incident rate immediately dropped from 7.4 to zero. The mill also ran one year with no MSHA citations. When this philosophy was implemented at the divisional level, the division's incident rate decreased from 9.5 to 1.1,an 88-percent reduction in six months.

Jan 1, 2000

By Vic Miller

Highly variable milling properties within a geologically complex porphyry copper deposit owned by Kennecott Corporation in Nevada made it necessary to estimate the copper recovery and concentrate grade in areas where actual test data was lacking. The estimation was made by first determining the relationships between the desired metallurgical properties and the ore's petrology (i.e. copper mineral type, rock type and copper grade). This relationship was then combined with the already estimated rock type, mineral type and copper grade data in the mineral block model to predict the milling properties.

Jan 1, 1983

By P. Henderson, M. E. Morris, W. A. Johnson, F. D’Alessandro, D. Wilton

"The objective of this research is to develop and apply computer models to evaluate the potential lightning impacts on underground coal-mining. These models can then be utilised to assist in the design of effective controls. This project will provide a significantly improved level of knowledge and control over current lightning abatement techniques. The findings may also be applied to open cut and coal preparation situations. Computer modelling identified that by isolating cased boreholes from underground conductive media such as roof mesh, and placing spacings between roof mesh the risk of an ignition can be reduced by more than a factor of ten. These controls should be applied in conjunction with minimising the potential for a flammable atmosphere to exist underground and ensuring that there is no transmission medium for the lightning to reach the atmosphere. INTRODUCTION The objective of this research was to develop and apply computer models to evaluate the potential lightning impacts on underground coal-mining. These models could then be utilised to assist in the design of effective controls. If successful this project would provide a significantly improved level of knowledge and control over current lightning abatement techniques. The direct potential for harm from lightning has long been recognised for the surface facilities of coal mines. However recent events at Blakefield South in NSW on January 5 2011 (DTI, 2011) and at Sago mine in the USA in 2006 (MSHA, 2007) have suggested that there is potential for lightning to cause significant damage to the underground workings of a coal mine. A very detailed analysis carried out by as part of the MSHA investigation into the SAGO disaster by Sandia Laboratories identified at least ten other incidents over the past thirteen years where lightning had probably caused the ignition of a sealed goaf area of a mine (SANDIA, 2011). In addition there is a long history of lightning related incidents in South African coal mines (Geldenhuys, 1985). Fortunately in those cases no lives were lost. The event at Blakefield South has suggested that there may be the potential for ignition to occur in an active longwall goaf. The potential for a lightning strike to ignite a flammable atmosphere in an underground coal mine has been demonstrated from the past experience both here and overseas. It requires three things: • Lightning • A mechanism to convey the lightning underground to the flammable atmosphere • A flammable atmosphere."

Jan 1, 2016

By B. V. Driga

The paper presents the evaluation method of the thermal power potential of the salt lakes developed in collapsed salt mines in Romania. It is well-known that the hydro-chemical stratification of these lakes favors warmer internal layers. The degree of heat varies during the year, but, taking into account the large number of genetic lakes of this type, it can be used as a local utilizable power source. The authors analyze the correlations between the physico-chemical parameters of the water and the degree of heat stored as a function of the morphological parameters of the lakes, as well as the technical parameters for capitalizing on this power.

Jan 1, 2008

By R. Todd Swinderman

Impact cradles are installed below the belt in conveyor loading zones to cushion the forces from material loading. In this paper, the author will discuss the need for and then explain the new CEMA standard for engineering of impact cradles. He will review the engineering theory and work through an example to demonstrate the assumptions used in the standard do not inappropriately affect the CEMA rating system.

Jan 1, 2002

By Ashis Bhattacherjee, Rahul Upadhyay, Nearkasen Chau, Aditya Kumar Patra, Dhanjee Kumar Chaudhary

Heavy earth-moving machineries used in openpit mines intensively expose drill operators to whole-body vibration and shocks, and thus to musculoskeletal disorders. The roles of individual, machine and rock-related factors in their exposure remain poorly understood. This cross-sectional study investigated their roles in 39 drill operators from Indian iron ore mines. It shows that 70 percent of the operators were exposed to high levels of vibration, above the limit values recommended by ISO 2631-1 (1997). Multiple linear regression models showed that the whole-body vibration and shock exposures were strongly associated with operator’s age, drill-machine model and rock hardness, uniaxial compressive strength and density. The role of body mass index was close to significance (p = 0.08). Univariate analyses found the drill’s age, seat-pad thickness and seat backrest height were also strong predictors. These results help in identifying risky operators, materials and occupational situations, and in implementing appropriate prevention and intervention strategies to reduce and monitor the exposures and health risk. In addition, during the planning stage of acquisition of new equipment, anthropometric data of the operators should be considered for the ergonomic design of the seat.

By G. W. R. Kuzyk

The Underground Research Laboratory (URL) , a major geotechnical research facility, is currently being developed by Atomic Energy of Canada Limited (AECL) , 120 km northeast of Winnipeg, Manitoba. The URL is part of the Canadian Nuclear Fuel Waste Management Program, which is assessing the concept of nuclear fuel waste disposal in a vault deep in stable plutonic rock of the Canadian Shield (Simmons, 1986). Comprehensive geotechnical research and development activities are being carried out in conjunction with excavation? and construction of the underground facilities.

Jan 1, 1989

By S. Tafazoli, D. Cooper, I. Bell, S. Nouranian, B. Sameti, M. Ramezani

"Image-based rock fragmentation sensing in mines and quarries includes an important rock boundary delineation step, commonly referred to as rock segmentation. This paper presents an artificial intelligence-based solution to this challenge. The proposed technique encodes prior knowledge of previously analyzed images into mathematical/statistical models. Human-labeled images are used as inputs to train neural networks through an optimization process. The networks can then be used in real time for rock delineation. To build the models, special deep artificial neural networks are used as a pixel classifier. The proposed classifier labels each pixel (edge, rock or fine) by analyzing a plurality of pixels within the image. Advances in machine learning allow the network to contain many parameters. The increased number of parameters is a strong factor in the classifier’s ability to correctly classify each pixel. Deep learning-based segmentation, combined with 3D imaging followed by post processing, provides a unified fragmentation sensing solution. Results from automatic segmentation are compared to human labeled segmentation using the percentage passing curves for 64 rock images. INTRODUCTION Mines and quarries can see significant productivity and performance benefits by controlling material sizes (McKee, Chitmobo, & Morrell, 1995; Sellers & Gumede, 2012). During the past decade, image-based fragmentation analysis has been applied to estimate rock size distributions in order to optimize procedures in mines and quarries. Using a roving camera and operator assisted analysis Maerz, Franklin, and Coursen (1987) measured the size distribution of the blasted rock and eliminated the need for manual sieve analysis. Since then, many others have introduced automated and manual methods for fragmentation analysis and improved upon existing approaches (Girdner, Kemeny, Srikant, & McGill, 1996; Smith & Kemeny, 1993; Palangio, Palangio, & Maerz, 2005; Tafazoli & Ziraknejad, 2009; Raina, 2013). In image-based fragmentation, rock boundaries are identified in the image, and an image scaling is applied to transform rock pixel sizes into real world dimensions. Usually geometric references, such as regularly shaped objects (discs and basketballs) (Siddigui, Ali Shah, & Behan, 2009), or the known size of an excavator bucket (Zeng, Chow, Baumann, & Tafazoli, 2012), are used to determine the proper scaling factor. In recent years, 3D imaging and sensing have also been incorporated to improve rock delineation. Specific methods include using camera-laser combinations and stereo imaging to measure rock fragmentation on conveyor belts (Noy, 2013; Thurley, 2013; Dislaire, Illing, Laurent, & Pirard, 2013) as well as portable fragmentation analysis devices with 3D imaging sensors (Sameti, et al., 2014)."

Jan 1, 2018

By K. Holmberg, D. Herriot

This paper by Mr. McIvor is yet another contribution to the eternal controversy surrounding the benefits, or otherwise, of high circulating loads in closed circuit grinding. Throughout the paper it is difficult to establish whether the author is referring to effects relating to the mill, classifier, or to the overall circuit. Table 1 is put forward as indicating the advantage of operating at high circulating loads. From the two (it would be interesting to see more) product sizing points provided in each case, the conclusions to be drawn are that cases one and two have very similar size analyses. The third case, however, indicates a much flatter curve, that is to say, higher fines production and a very wide spread of size ranges. If the objective of this circuit is to provide a closely sized product with minimum overground slimes to the downstream process, then it would appear to be the less "efficient" by far. No data is given for product pulp densities either. The term "efficiency" should never be used without a careful and clear definition. In this case, "efficiency" is used to express an apparent percentage reduction in operating work index (Bond) from the measured "standard" at 250% circulating load operation. The Bond calculation is itself based upon

Jan 1, 1990

By Carl G. Schwenk

Rusk County is located in the northwestern portion of the state of Wisconsin, roughly 130 miles east of Minneapolis (Figure 1). The topography is generally flat with dairy farming the principal activity. Forest and swamp lands are common, as well as pasture and cultivated ground. Rusk County falls near the southern terminus of the Precambrian Shield and is covered by a thick layer of glacial drift. Outcrops are quite rare, but the few available exposures indicate that the subsurface is comprised of steeply dipping metamorphosed volcanics and sediments of Early Proterozoic age. A thin section of flatlying Cambrian sandstone is sometimes found directly under the glacial till. The depth to Precambrian basement has been recorded to be as great as 150 feet beneath the surface.

Jan 1, 1976

By R. Z. Pyrih

Pressure/ ,acuum lysimeters were used to instrument column tests containing several lifts of tailings slurry, and to sample pore water as the tailings lifts dried. The results of the column testwork demonstrated that air oxidation of sulfide minerals associated wilh the tailings residue neutralized the alkalinity of the tailings pore water. Neutralization of the alkaline pH volatilized cyanide which, in turn, destabilized copper-cyanide complexes and caused the precipitation of insoluble copper from solution. Analyses of pore water samples for microbial activity indicated high plate counts. The presence of viable microorganisms in the pore water implied that degradation of cyanide was enhanced by growth and activity of cyanide-consuming microorganisms in the tailings material.

Jan 1, 1991

By Nobuharu Isago, Atsushi Kusaka, Kosuke Kawata, Dohta Awaji

"The immediate ring closure method, in which the entire periphery of the excavation area is closed immediately with an initial support within a short distance from the excavation face, has been increasingly used in Japan, especially, as one of the most effective countermeasures against difficult ground conditions in conventional tunneling. For reasonable design of this method, the performance requirements for the initial support should be clearly stated. The analysis of construction data of 30 road tunnels and the three-dimensional numerical modeling based on real data suggest that the immediate ring closure stabilizes the tunnel structure and the ground around it because of the inner pressure effect of the initial support, especially, for low ground competence factor and small internal friction angle. Finally, the bending compressive strength and the cross-sectional geometry of the initial support have to be considered in the tunnel design while considering the earth pressure and ground properties. INTRODUCTION Conventional tunneling methods often deal with difficult ground conditions such as soft ground or squeezing ground conditions. The immediate ring closure method, in which the entire periphery of the excavation area is immediately supported within a short distance from the excavation face (Figure 1), has been increasingly used in Japan as one of the most effective countermeasures against difficult ground conditions in conventional tunneling (e.g. Takahashi et al., 2011; Nakaoka et al., 2013). The immediate ring closure method was empirically identified as effective for reducing ground surface subsidence and tunnel deformation. However, the working effects of the method have not been clarified sufficiently. To improve the design of this method, the working effects of this method and the performance requirements for the initial support need to be clarified. The relation between the effect of immediate ring closure and earth cover has been clarified (Mashimo et al., 2008; Awaji et al., 2013),"

Jan 1, 2016

By Donald L. Bott

A computer model called the Quality Compliance Model was developed to optimize the mine planning and sequencing in area coal mining with respect to the limit on pounds of sulfur dioxide per million BTU imposed by regulations. The objective of the model is to maximize the amount of high sulfur coal mined from various benches while meeting the specified compl'ance standards. Given multiple seams and multiple benching operations, the mining sequence from each pit is simulated. The rate of mining is controlled such that the in-pit blending will maximize the usage of high sulfur coal and meet compliance standards. The compliant coal can be stockpiled for usage at a later date, or it can be disassociated. This calculation can be based on any given rate of production, i.e., from as small a unit as a unit train to as large as monthly or yearly production.

Jan 1, 1982

By G. Gaidajis

In this paper, a semi-qualitative methodology is presented and then applied to an aluminium extrusion industrial facility in order to perform an initial environmental assessment. The results of the assessment enable an improved understanding of the environmental performance of the facility and more importantly identify the areas of significant environmental concern. Following, the application of case-specific sustainability indicators related with the areas of significant environmental concern, leads to a more comprehensive sustainability assessment. The applied two-step approach offers a quick and reliable environmental assessment and help focusing on the most environmentally problematic areas. Moreover, the follow-up of the specific indicators seems to be appropriate for the improvement of the environmental performance of the examined industrial facility.

Jan 1, 2008