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By J. H. Kempton, D. Atkins, W. Locke

The scrutiny given to model predictions of pit-lake water quality has focused attention on the uncertainty associated with long-term predictions. Although comparison of probabilistic predictive modeling of water quality in existing pit lakes suggest that short-term predictions can bracket most parameters, un¬certainties in wall-rock reactions and the stability of groundwater composition and climate remain unquantified This overview of the uncertainties associated with longer-term predictions is presented as support for those considering policy decisions that must be made in the absence of reliable estimates of future conditions.

Jan 1, 2000

By Bart Lorang

Mining and mineral processing companies have historically leveraged technology and science to the fullest to reduce costs and improve product. Information technology is arguably one of the fastest moving technologies used by the mining industry. However, the business model for managing that technology and IT professionals often is fundamentally the same model that evolved from 1960's mainframe era. This paper will present a perspective of today's technology; review emergent computing technologies and attempt to id- advancements in computing anticipated in this decade. It will then discuss how the traditional IT model fits the technologies of today and the next decade. It will suggest roles IT professionals may play in the future to best leverage these technologies.

Jan 1, 2002

By N. I. Fedunets

The development of variousworks on automatising of operational processes at coal¬extractive and coal-mining enterprises introduces an ever growing necessity to carry out investigations in the wide range of problems concerning the possibitity of joint functioning of different levels, which seems impossible without the use of integrated systems of passing on and prossessing the information on the basis of modern calculating machines and other means of automation. This view on the problem of automation of the enterprise operation presupposes that the structure of automated operational dispatcher control (AODC) should be very closely connected with that of integrated data processing system! In this case the AODC structure from the point of view of automation of its functions (or operations), i.e. from the point of view of informational techniques coinsides in general with the structure of dispersed information and calculating network (ICN), realizing the passing on and processing of the information as well as solving the functional tasks on the basis of local calculating networks of electrical calculating machines with correspond to different levels of AODC and located with regard to productional hierarchy of operational dispatcher control (ODC). In this approach however the use of dispersed, ICN gives opportunity to. realize the possibility of action only with realisation on the CM of algorithmic' task of ODC, when a dispatcher 'is the lastto make a final decision.. At the mining enterprises it's rather difficult for a dispatcher to make a final decision because of the great variaty of productional situations, the presence of contradictions and a number of other subjective factors which often lead to the dispatcher's mistaks causing great material losses of the enterprise. Hence the necessity arises to automize and formalize making a decision and including the expert systems (ES) into the ontour of AODC, which enables the dispatcher 2to get a neeessary advice in different situations, especially in case ofemergency on the basis of establishing the mechanism of logical layout of non-formalized data base (DB) procedures relying upon the background knowledge and experience of experts. The presently presented in this paper theory of establishing the. ISAODC on the basis of dispersed ICN and expert systems is aimed at trasformation ofoperational' tasks of the higher level into the technological ones, at solving the tasks of diagnostics and forseeing of the process of production, with a dispatcher getting an opportunity of making qualitative and effective decision concerrning the choice of operational impacts in actual time on the basis of generalization the realisation of presented conception must, as has been already mentioned, be accomplished only on the basis of the foundatoin of the united dispersed informational - calculating network of electrical calculating machines.. This includes ICN which would be operating in . different operational contours. . From what has just been said it followsthat the ISAODC Structure will conside with that of DICN (in our case) and hence all the problems of ISAODC structure would be regarded as the questions of DICN.

Jan 1, 1992

By Etienne Simode

When a fire breaks out in a mine access road, the hot smoke, due to heat transfer with the surrounding strata, progressively cools as it moves forward. Depending upon the resulting temperature distribution, the density of the fluid changes. This change will bring about: Firstly, a variation in the resistance of the roads, a static factor which will affect ventilation flow rates; Secondly, the appearance of extensive aerodynamic driving loads in the vertical and angled roads, a dynamic factor which can have an extensive impact on ventilation. Because of the appearance of combustion and distillation products, the vaporization of water, which wets the timbering and strata, and the expansion of gases, fluid rates can at times be increased tenfold in the area of the fire. These disturbances may cause explosions and ventilation inversions, which fill other working areas with smoke toxic to workers, and which can come up upon rescue teams from behind. Due to the progressive heating of the surrounding rocks, which will slow down heat transfer, these dangerous conditions change over time. At the Lorraine Basin Coal Mines, programs have been set up and employed for the computer simulation of these phenomena over time. They serve to anticipate or to understand such phenomena, the input data being the characteristic parameters of the mine ventilation network, the operating curve of the main fans, and measurements or estimates of some temperatures. Two programs, employed together, have been developed for these studies: One program, called RESO, calculates the distribution of flow rates and pressures throughout the entire network; The other, called FEUMIN, determines smoke temperatures over their entire path.

Jan 1, 1980

By Joe Komadina

DOUG HALBE: Our next topic is one that I would think everyone might want to contribute to. I'm sure everyone here has had some experience in this area. If you haven't, I'd suspect you've never really run a mill. This is what we call "Horrible Spill Areas We Had When We Started Up the Plant and How We Fixed Them." Our next speaker has had a really great operating career. He had many years with Newmont in the Carlin area, and now he's executive vice president and chief operating officer of Independence Mining Company: Jim Komadina. I don't have to be nice to the speakers anymore, do I? [laughter] You may wonder why we picked Jim Komadina to give this talk. I was involved many years ago in the start-up of Newmont7s Gold Quarry plant. Jim held quite a responsible position there. I'm not going to say anymore, but I have in the back of my mind this picture of the pump floor and a rowboat and a guy rowing around on the pump floor. [laughter] Jim, was that you? [laughter] JIM KOMADINA: Probably. I wasn't responsible for the design. [laughter] Actually it's amazing. I've seen a lot of these plants and actually had the opportunity to walk around them, so when I say this, "Horrible spills I have seen and done," it's because I've been responsible for more than my fair share of them. But having seen a lot of spills, I will present a little bit of wisdom about how to prevent them.

Jan 1, 1998

By René E. Fuenzalida

The copper market has become highly competitive around the world; therefore, operations efficiency is a must for copper producers. The economic outcome in a day-to-day milling is not evident at the concentrator stage, when traditional procedures are used in operations management, based on the supervision of process variables and metallurgical indices. Therefore, in such a complex business, there is a strong need to devise an approach to furnish concentrator's operators with procedures and tools to state and solve the problems related to operational decision making, leading to maximize the economic return of investment; this is what is aimed to be presented in this paper.

Jan 1, 1998

By M. Amick, G. Swan, R. Hill, C. Pritchard

Falconbridge is a major basemetal producer in the Sudbury Basin of Ontario, Canada. The company identified a need to find a safe and cost-effective replacement for the welded wire mesh used to support loose ground during underground nickel mining. Falconbridge took a methodical approach to the concept of a spray-on liner as a screen replacement, proving the strength characteristics of the liner as a safe, cost effective and suitable method of supporting ground Compact, hydraulic mixing and spraying equipment were developed and are now in use at the Fraser Mine. Tekflex has been approved as a wire mesh replacement and has been in use since November 1998.

Jan 1, 2002

By Edward Finch, William F. Riggs

Selectivity and recovery of many industrial minerals can be directly affected by the carbon length, degree of unsaturation, and melt point of fatty acids used as collectors. Examples of several modifications are provided based on actual experiences of commercial applications. A review of recent history indicates that fatty acid collectors are applicable from C9'C18 in carbon length, however, not for all minerals. The mesh size, density, and surface characteristics of the particular mineral, as well as other related operating conditions, are important in selecting the correct fatty acid configuration. A review of some past programs are submitted as a guideline in the selection of fatty acids and supported by isolated, successful examples demonstrating the effect of carbon length and unsaturation.

Jan 1, 1986

By M. Gershon

Four computerized approaches for coal blending are described and their strengths and weaknesses are explored. Spreadsheet analysis Other than word processing, spreadsheet software is the most commonly used software. Its wide availability and ease of use are two desirable features that have led many to try to adapt it to the purpose of coal blending. These are the two main advantages of this approach. To use a spreadsheet for coal blending, each row of data represents one source of coal. Each column represents a quality of the coal, with the last column specifying the tonnage of that coal in the blend. The calculated figures are. the blended qualities, which can be programmed to appear in the bottom row. A trial-and-error approach is then used to develop the best blend. Inserting any blend in the last column provides the blend characteristics at the bottom of the page. If any specifications are not met, the blend can be changed, all calculations being immediately updated. This process is repeated until all specifications are satisfied. A third advantage of this method is that it is exactly the procedure that one would go through if doing this by hand. With a spreadsheet, many more blends can be evaluated in much less time, allowing the designer to try to improve over satisfactory blends to find the best of them. The resulting improved blends or cost savings are a fourth advantage of this approach. There is only one major disadvantage of using the spread- sheet. This is that most probably the best blend is not found. As an inexpensive introduction to computer-assisted blending, which can be easily understood and cost just a few hundred dollars, this is a recommended place to begin.

Jan 1, 1987

By V. E. Suter

Anyone with geothermal experience can readily attest that geothermal operations are a natural extension of oil and gas operations. A geothermal company and an oil company need the same type of people to do the same kind of work. In the geothermal industry, geologists and geophysicists define prospects through surface geology, analysis of surface seeps, magnetics, gravity, and resistivity surveys - techniques similar to those used in the petroleum industry. In addition, shallow (250-ft) temperature gradient holes often are used in geothermal operations. Landmen take geothermal leases that are patterned after oil and gas leases. Exploratory drilling is done with the same drilling contractors and same drilling rigs, with minor modification. Drilling foremen and drilling engineers share the same objective of making the most hole, in the shortest time, at the least cost, with a proper completion. Petroleum engineers test the wells, design the completions, determine the reserves, make economic calculations, work with the tax assessor, and manage the reservoirs. Production engineers build roads, locations and pipelines, install gas/liquid separators and meters, and operate production and injection facilities. A contract to sell steam to a public utility is required. Various governmental regulations, permits, environmental concerns, and public affairs pose similar problems in both industries. Also required of both are top management people who are acquainted with geologic risk, prepared to accept million dollar dry holes, willing to bid competitively at lease sales, and able to invest large sums based on a technology not yet fully proven. Successful geothermal development requires in-depth financial ability similar to that required for petroleum development. A high capital investment is required early for leases, geological and geophysical work, and exploratory and confirmation drilling. After

Jan 9, 1980

By Hill McDonald

Sand and gravel deposits may be explored by many different methods. The methods used by The Standard Slag Company are primarily two in nature. One is using an auger which is limited in depth by various soil conditions. The other is a heavy wall dry sampler and a heavy wall wet sampler. The heavy wall dry sampler takes continuous uncontaminated samples up to seven inches in diameter. The heavy wall wet sampler takes continuous uncontaminated samples up to six inches in diameter. For us, the maximum depth of the heavy wall samplers has been two hundred fifty feet of which one hundred feet was above the water table and one hundred fifty feet was below the water table.

Jan 1, 1972

By Jack R. Nawrot, R. E. Lounsbury

Preservation and replacement of wetland habitat has become a National priority. Lands affected by mining can provide an excellent opportunity to develop wetlands where none currently exist. This proposed end use for land can require converting quality farm land from its pre-mining farming capability. Where such conversion is necessary, environmental regulatory authorities in lllinois have come to view wetlands among the preferred restoration alternatives. Research and large scale demonstration projects conducted by the Cooperative Wildlife Research Laboratory at Southern lllinois University at Carbondale have shown that coal slurry ponds can be reclaimed to wetlands. Key to successful wetland establishment is recognizing distinct zones in the slurry surface to be vegetated and treating these zones with appropriate soil amendments and plants.

Jan 1, 1991

By D. W. Boening

Xanthate salts have demonstrated effectiveness as a flotation reagent in the recovery of heavy metals from mining wastewater. However, due to their strong ionic potentials, they are generally toxic to aquatic life. Under ambient environmental conditions, the half¬life of a xanthate is approximately four days. As a soluble salt, xanthates will complex with the metallic ions contained in water and fish. Some researchers have proposed that this complexing may extend the halflife, as well as optimizing the transfer of a given metal from solution across the gill surface. Leakage of xanthate treated wastewater into the surrounding surface waters is the most common route of exposure for aquatic plants, invertebrates and fish. Because this is an emerging mineral-recovery technology, more information is needed regarding xanthate toxicity and environmental fate before environmental impacts can be assessed with any degree of certainty.

Jan 1, 1999

By L. A. Puchkov

The creation of automatic methane concentration control systems presupposes the use, as a control factor, of the air rates in workings and in mine as a whole. These systems present a complicated set of computers and software, including as major components the following - systems for detecting methane concentration and air rate; - telemechanics systems; - programs and means of data processing; - programs and means of air rate control in workings and main fan capacity control. The paper analyses the experience of development and exploitation of automatic methane control system in gassy mines of the USSR Donetz coal basin. Much attention is given to the study of technological factors influence upon aerogasdynamic process using automatic methane control system.

Jan 1, 1989

By Bryan A. Bartley

About 1,000 machines around the world are breaking rock and hard abrasive materials by a very economic, high intensity, autogenous process, but this method is largely ignored by the mining industry. This vertical shaft autogenous impact crusher has impact velocities around 70 m/s, which compare with those of Cascade and SAG mills of up to 10 m/s. The autogenous impact, breakage processes are all at higher intensity levels and the products reflect this difference. The topic of liberation is breifly considered. A series of tests with a laboratory scale machine are reported to illustrate a number of the characteristics of the process. This paper highlights topics for further evaluation and research.

Jan 1, 1992

By J. Paraszczak

With regards to the cost and profitability of a mining operation, the performance of the equipment employed is one of the key issues. Cost and profitability depend on, among other factors, the reliability and availability of the equipment. In an attempt to reduce equipment downtime, it is indispensable to collect and analyze reliable data and information on failures and maintenance actions. This paper reviews common problems encountered in this respect, with particular emphasis on the lack of uniform terminology and methodology. Recommendations concerning the standardiztion of reliability and maintainability concepts and measures are given. Regarding the benefits that the latter may bring, the paper concludes with a proposal for an industry-wide initiative in this respect.

Jan 1, 2002

By C. Tsamantaki

Water-bentonite suspensions exhibit a yield stress which is defined as the minimum applied stress for flow. Considerable debate exists about the yield stress being a material property, hence different measuring methods should give similar answers, but several investigators have demonstrated that it is an engineering reality. Yield stress is normally estimated indirectly from the rheogram obtained with a viscometer following an extrapolation to zero shear rate (the dynamic yield stress), but the technique may be prone to errors because of slip flow. Direct measurements, not prone to such errors, rely on an independent assessment of the yield stress, normally carried out with the vane method (the static yield stress). In this paper results are presented and compared regarding the yield stress of 14 different water-bentonite suspensions measured using both the direct and the indirect methods. In order to obtain a wide range of yield stress values, two different types and two concentrations of bentonite at various pH were tested. Rheological data were obtained using a rotational speed viscometer and a yield stress vane measuring device. Measured vane yield stress values ranged from 5 Pa to 83 Pa. Rheological data collected with the rotating viscometer were fitted using various conventional techniques (interpolation, linear and non-linear regression analysis) as well as using a golden section yield stress search methodology based on Herschel-Bulkley model, developed in house. The vane instrument measures directly the yield stress of the suspensions and requires no further data handling. A comparison of the measured values of the yield stress with the direct and the indirect method is then made for the water-bentonite samples. Not very large differences are observed among different techniques and the variations are discussed. Similar data from literature are also analyzed and the comparison shows that differences on the various estimation methods are much larger than the differences observed in this study.

Jan 1, 2006

By Dave Willis

In ME'S 1994 Powder River Basin (PRB) coal transportation article, the lead author described some destinations pursued by the railroads. As with many destinations, though, they turned out to be merely stops on the way to places that have yet to be reached. Along the way, the railroads discovered that making it better is a continuous process, not just something done in several phases. This was always known but not at the awareness level that exists in 1998 railroad environments. This update of the 1994 article includes railroad companies' plans for the future of rail transportation in the PRB.

Jan 1, 1998

By Jerry Demchuk, Allan Flemming, Stephan Day

Luscar Ltd. is currently developing open pit mining plans for the Telkwa Coal Project. Most waste rock is predicted to be non-acid generating but a proportion (less than 20%) is potentially acid generating. The waste management plan includes in-pit and ex-pit disposal of blended and till-capped waste rock, segregation and in-pit encapsulation of strongly potentially acid generating materials, and in-pit underwater disposal of coarse and fine tailings. The paper will present the steps used to design the waste management plan including the development of geochemical design criteria using various tests and theoretical and practical knowledge of waste behaviour.

Jan 1, 2000

By Ruston A. Ford

This paper reviews the development of the David Bell Mine, from early exploration, through discovery, construction, start-up, underground development, and production. Details are provided regarding the mine development, the mechanized cut and fill stope production, the proposed long-hole stoping with delayed backfilling mining method for the lower levels and the cyanide leach carbon-in- pulp concentrating process. The mine development remains on schedule and under budget with results very much as predicted in the feasibility study.

Jan 1, 1987