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A number of factors have resulted in the widespread use of computer simulation as a day to day tool in the mineral processing industry, as is the case in most engineering disciplines. A number of simulation packages, both steady-state and dynamic are now available commercially. The developers of such software face an enormous challenge in maintaining and improving the packages due to the complexity inherent in such systems. This problem known as the software crisis faces all developers of complex software. Object-oriented (OOP) and design is a methodology which has been developed to try and minimise this problem. The use of the OOP paradigm in the devlopment of simulation software for mineral processing systems is explored in this paper and it is found that OOP techniques have major benefits for the design and development of such software.

Jan 1, 1992

By Claes G. Björk

Over the past decade mined unlined rock cavern storage for crude oil and refined products has become economically more attractive. This trend is likely to continue, primarily due to advances in excavation methods, rising steel costs for above ground tanks and larger capacity requirements. The construction experience related in this paper comprises the excavation of more than 80 storage facilities (total capacity 90 million bbl) for crude and refined products ranging from propane to heavy fuel oil. This paper also deals with the experience gained as well as the problems derived from the utilization of these oil storage facilities.

Jan 1, 1981

By J. A. Burger

Research in the eastern U.S. has shown that productive mine soils and forests can be restored using the following guidelines: (1) cooperation among the mine operator, landowner, and regulatory authority in developing the mining permit; (2) replacing topsoil or creating a desirable medium in which trees are planted; (3) loosely grading non-compacted topsoil; (4) using native and non-competitive domestic ground covers that quickly protect the site; and (5) planting a proper silvicultural mix of crop trees for their commercial value along with nurse trees for wildlife and soil improvement.

Jan 1, 2002

By Richard E. Gertsch

The recent upswing in mining coincided with increased environmental concern. These trends have significantly increased regulation, but have not always provided sound environmental protection. Throughout, mining has remained passive, reacting to initiatives from outside. The high road to environmental protection must be an active strategy. The mining industry must take the lead and develop an environmental program effective in price and protection. It must involve all levels of mining. The mining industry should be the real environmental activist. We have the most to gain by sound environmental protection and the most to lose if the environment decays.

Jan 1, 1991

By J. A. Brierley, R. Y. Wan

Newmont Gold has advantageously used the capabilities of mineral oxidizing bacteria to develop a process for the pretreatment of low-grade sulfidic and carbonaceous-sulfidic refractory gold ores. The biooxidation process results in the oxidation of the sulfidic minerals with increased exposure of gold for subsequent gold recovery. The biooxidized carbonaceous-sulfidic ores cannot be heap leached with cyanide because of the preg-robbing characteristics of the carbonaceous matter in the ores. Therefore, an alternative heapleach process using ammonium thiosulfate was developed to extract gold from these preg-robbing biooxidized ores. The ammonium thiosulfate leach process was successfully applied in both laboratory and pilot plant tests. Satisfactory test results were achieved, encouraging the continuation of process development.

Jan 1, 1998

By J. S. Long

A finite-difference model using a digital computer was constructed to assist in the water management of a proposed oil-shale mining operation in the Piceance Basin in Colorado. The presence of ground water is both a detriment and a benefit for development of the resource. On one hand, dewatering is required because permeable zones are present in and above the oil-shale sequence, and rich oil shale at the proposed mine is as much as 457 m (1500 ft) below the water table. On the other hand, ground water is the most feasible source of water for processing the oil shale. A ground- water model was constructed to simulate the development of an environmentally acceptable water-management system that will satisfy both the mine-dewatering requirements and the water-supply requirements for processing. The ground-water model discussed in this chapter was constructed for the Rio Blanco Oil Shale Co. (RBOSC) by International Engineering Co., Inc., a subsidiary of Morrison-Knudsen Co. The model was applied to evaluate dewatering and water control systems for several open-pit mining plans initially investigated to develop Federal Lease Tract C-a. A collateral application of the model analyses was to project effects of the proposed dewatering operation on the regional ground-water regime in connection with a permit acquisition program by RBOSC. Subsequently, RBOSC has completely changed its mine development plan and has adopted modeling and related techniques more suitable for study of that plan and dewatering operation. The authors of this chapter are solely responsible for the contents and conclusions.

Jan 1, 1979

By R. Schuerch, G. Anagnostou, R. Poggiati

"The paper presents dimensionless design diagrams for estimating the stand-up time of a tunnel face in saturated ground of medium-low permeability. The diagrams cover a wide range of ground parameters and apply to shallow tunnels (overburden less than two diameters). As the time-dependency of the face stability in water-bearing ground is associated with the consolidation process in the soil ahead of the tunnel face, the stand-up time is determined by means of hydraulic-mechanical coupled spatial stress analyses. The results presented are important for tunnel engineering practice, e.g. when estimating the feasibility of atmospheric interventions in the working chamber of a closed shield. INTRODUCTION The response of water-bearing medium-low permeability ground to tunnel excavation is time dependent. The time-dependency is due to a transient seepage flow process that is triggered by the excavation and develops slowly over the course of time. Experience shows that the short-term behavior the ground is more favorable than the long-term one: the deformations increase with time; the tunnel face may be stable initially and fail only after some time. The time over which the tunnel face remains stable is called the stand-up time. This paper investigates the time dependency of the tunnel face stability assuming that all time effects are due to consolidation rather than creep. This assumption is reasonable for shallow tunnels crossing water-bearing soils. In the problem under analysis, the unsupported tunnel face remains stable under the undrained conditions prevailing after excavation, but collapses before reaching the drained conditions prevailing at a steady state. The assessment of the stand-up time is important from an economical point of view for both mechanized and conventional tunneling through weak water-bearing ground, as a long stand-up time removes the need for face support or ground improvement works during standstills, thus saving time and money, while short stand-up times require hyperbaric interventions or the implementation of costly and time-consuming auxiliary measures."

Jan 1, 2016

By J. Mastoris

The determination of the surface area that may be impacted by underground mining is an important consideration in subsidence engineering. A number of parameters have been utilized to identify this influence area, most notably the angles of draw and break. This paper discusses the implications of selecting an appropriate "damage angle" for defining a potential damage area due to mining, within which surface structures may be impacted. Furthermore, the influence of both mining and geological factors (i.e., mining width, depth and overburden lithology) on this angle is examined using the Surface Deformation Prediction System (SDPS) software. Finally, recommendations are given for applying these concepts in subsidence control.

Jan 1, 1995

By Sergey G. Pushkin, Eugeny L. Schastlivtsev, Anatoly A. Bykov

Three years ago the authors and a group of assistants began to develop a GIs-system for integration of comprehensive eco- logical information to be linked to geographical maps of Kuzbass region. And now we have got the working system and some first results that the present paper deals with.

Jan 1, 1996

By R. E. Driscoll

The exploration, geologist of necessity has to have a wide working knowledge of many specialties other than hiw own, First he has to use his own technical background to find a deposit,, of a mineral that is of interest, Once found, his problems are Just beginning, He then has to assume the role of an economist, an accountant, a mining engineer, a chemist, a metallurgist,, a salesman and what-have you, In the economic field, he must determine the marketability of either the ore or the refined mineral. He must gauge the supply and demand for the particular mineral he is interested in and make his best guess as to ultimate cash flow from a deposit over the estimated life of said deposit, He must then assume the role of a mining man and estimate cost of recovery, including an, evaluation of the most economic mining method, cost of supplies and labor, and again estimate a net cash flow. He must then determine amenability of ore to economic metallurgical methods, he must determine the legal status of the property involved and, after analysis of the specific situation, determine the best approach to a deal, After all of this he must sell it to the people who will put up the money and then put his deal together and sell it to the people who own the minerals, if that be necessary. Then he has to sit back, with crossed fingers and crossed legs wondering for some months, and in many cases even years, whether or not he is right. The expenditures required to open up a mine in this day of wild inflation are such that he has to be right, and the responsibilities are awesome.

Jan 1, 1958

By John F. Schat, T. William Thompson

Laboratory data on the time-dependent compaction of porous rocks are presented, and various attempts to model this behavior are described. These lead to a discussion of the problems that arise in using laboratory data to estimate long-term effects. A method is suggested for combining laboratory data with information from the geologic record to estimate long term effects.

Jan 1, 1986

By Levent Ozdemir, Russell Miller, Fun-Den Wang

The full utilization of tunnel boring machines for excavation in medium hard and hard rock has been limited by insufficient knowledge of rock behavior under the action of mechanical cutters. An understanding of factors affecting the rock removal process will permit: (1) the more efficient design of tunneling machines, (2) the prediction of boring performance from geologic data and cores taken from the proposed tunnel alignment, and (3) an improved excavation rate, thus a lower tunneling cost.. The Colorado School of Mines, under the sponsorship of the National Science Foundation, is studying the effects of a number of parameters in regard to tunnel boring using both full and small scale laboratory tests, analyzing field boring performance and comparing the laboratory and field data. Results indicate: (1) the field boring performance can be reproduced in the laboratory, (2) the optimum spacing of cutters or optimum spacing to penetration ratios may be found in laboratory testing, (3) it is promising to use small core samples and laboratory testing to predict field machine performance and (4) effect of joints on boring rate is significant and should be included in predicting tunnel boreability.

Jan 1, 1974

By Jiqing Zhang, Jon C. Yingling, Andrzej M. Wala, Richard Ray

The purpose of this paper is to present how Computational Fluid Dynamics (CFD) simulations can be used to study the flow across the main airways of a mine ventilation system. in particular, the flow through the transition zone between the upcast shaft and main fan ductwork was investigated. These studies consider potential design modifications of this transition zone to reduce the energy cost. Although CFD has many advantages, it does not completely eliminate the need for experiments, which are still needed to validate numerical solutions. For this reason, data collected during actual mine tests and CFD simulations are compared in this pa- per. This comparison allows a better understanding of the flow phenomena. Moreover, once the numerical solutions have been validated, CFD can be used with better confidence to predict the effect of changes in ductwork configurations on energy losses. CFD reduces the number and cost of tedious experiments, while enabling a broader scope of design comparisons.

Jan 1, 1997

By Adrian Smith, Debra W. Struhsacker

There is now overwhelming evidence that, despite concerns to the contrary, natural degradation of cyanide and cyanide attenuation by hydrogeochemical processes are capable of minimizing or eliminating potential water qua1ity impacts from heap leach systems. A1 though there was some recognition of these data by the regulatory authorities, for example the initial USEPA modification of cyanide standards to an advisory level, many states have codified standards inappropriate to the clearly site specific nature of heap leach operations. As an overview to this problem, this paper will integrate the theoretical chemical data on cyanide with the observed geochemical behavior of cyanide in the decommissioned heap leach environment. The cyanide species that are likely to exist within an abandoned heap leach system will be identified, and the relative toxicity and potential environment effect of these cyanide species will be discussed. These data will then be used to evaluate cyanide detoxification regulations for decommissioned heap leach projects in 14 states.

Jan 1, 1987

By M. Henneman, M. Kosma, M. Eyll-Vetter

"For a long time, the recultivation of depleted opencast mines and operating systems was aimed at restoring the original state. The focus, as desired by policy-makers and the local population alike, was on restoring high-quality agricultural land and on creating reforested areas of value that suit their location. Until the turn of the millennium, recultivation measures were only rarely the subject matter of public planning processes beyond these general objectives. They were never regarded as nucleus and origin of sustainable structural developments. The rehabilitation of inactive lignite opencast mines in central and eastern Germany brought about a change in mind-set that understood recultivation to be a unique opportunity to completely redesign a landscape and gear it towards the future in the Rhenish mining area as well. The ""Inden residual lake"" and ""terra nova"" projects, planned in the last 10 years in cooperation with policy-makers and authorities, are two undertakings that provide sustainable structural impetus for the future today."

Jan 1, 2011

By J. J. Bean

The development drilling program of the Copper Cities mine indicated that the molybdenum content of the ore would be about 0.011% MoS2' The molybdenum content of the Miami mine at the same time was about 0.025% MOS2' The Miami mill had a very successful molybdenum operation which used bleeder turbine steam from the Miami power plant for the steaming operation. The much lower grade of the Copper Cities ore, the absence of a source of low cost steam and the use of sodium aerofloat as the copper collector which Miami experience indicated did not respono readily to the steaming technique made very doubtful the success of a similar operation at Copper Cities. However, the relatively few pounds of copper that could be recovered from the low grade Copper Cities heads made very desirable the recovery of the molybdenwa,as a source of additional revenue. Accordingly, shortly after the Copper Cities mill began operation, a research program was instituted to develop a suitable method of molybdenum recovery. This program explored first, the successful steaming process then in use at Miami and as expected, found it unable to decompose the sodium aerofloat copper collector. The known chemical depressants were then tried without much encouragement. Finally the copper concentrate was dried, not roasted, to 2-3% mOisture and this along with sodium ferro-cyanide and cyanide resulted in sufficient copper depression that a final molybdenum concentrate containing 1.0% CU could be made. The bench scale testing was followed by pilot plant testing. Sixteen

Jan 1, 1972

By Malcolm Scoble

This contribution examines the motivation and prospects for mining companies to become Learning Organizations and integrate Lifelong Learning into their culture. Mining Schools have a potentially central role to play in developing Learning systems for access by industry. Reference is made to initiatives to develop a system that is based on collaboration between UBC, Edumine and the Canadian Institute of Mining, Metallurgy and Petroleum. Recent experiences with this model are reviewed.

Jan 1, 2005

By Bekta? Uz

In this research, geological characteristics of sand quarries around the village, Kemerburgaz Akpinar, are studied and the mineralogical, petrographical, chemical and technological characteristics (such as sieve analysis, relative density, water absorbtion etc.) of the sand samples, obtained from the area are explained. In the general area sand' quarries, being in lacustrine formations belonging to Neogen, the stratigraphic location of the sand occurences take place at high levels of these formations, geologically. All of this pattern, being under 1 mm with a ,particle dimension, it ranges from 0,5 mm in the quantity of 99 % to 0,25 mm in the quantity of 15 relative density is 2,65 g/cm3 ; water absorbtion is 0,9%. Mineralogically, the sand samples contain Quartz (84%), Feldspar (3%), Calcite + Aragonite (10%), Pyroxen+Amphibole (1-2%), Garnet+Tourmaline (0.5%), Olivine (0.1-0.5%). Besides, sand samples contain SiO2 with the quantity of above 90%. Containing Quartz at high levels for mineralogical, petrographical and chemical characteristics, Akpinar sand will be evaluated as silica sand when the carbonate mineral is removed with the method of ore preparation such as leaching.

Jan 1, 2005

By Reed J. Irvine

One normally does not find sudden and dramatic changes in the investment climate, barring the unexpected outbreak of-wars or revolutions. Asia has seen a fair amount of military action and revolt during the past year, not all of it unexpected There was the fighting in Laos, which resulted in the as yet unconcluded negotiations which will probably lead to the establishment of a neutralist regime. In April of 1961 another revolution occurred in South Korea, and the elected government was replaced by a military dictatorship.. Communist guerrilla activity in South Vietnam was stepped up, and uncertainty about the future of that area increased. Relations between Pakistan and Afghanistan became more strained, and while no fighting has broken out, diplomatic relations between the two countries were broken off. India was both the victim of further incursions of her territory by communist China and the perpetrator of the forcible seizure of territory from Portugal. Indonesia has been making preparations for an armed attack on the Dutch in New Guinea.

Jan 1, 1962

By Michael J. Shulman

Outcrops of the Nubian Sandstone Series cover approximately 180,000 km2 in southern Egypt. Within the series, oolitic iron ore beds occur. The only comprehensive information available on stratigraphy of the iron beds is for the area east of Aswan, otherwise information is exiguous, sparse or unreliable. Based on this low level of information, the iron potential of the Nubian Sandstone Series was assessed and an exploration strategy formulated specifically tailored to the assessment. The area covered by the Nubian was divided into five regions, each comprised of 100 cells. A spatial distribution, i.e. negative binomial, was assumed adequate to describe the number of targets per cell and was indirectly calculated using a compound poisson distribution. Estimate of the only unknown parameter - the average number of targets per cell - implicitly/explicitly incorporated available geologic and economic information into the assessment. A probability distribution for the number of targets per region was then derived from the cell probability distribution. An allocation model based on the regional probability distribution assessment as well as on an estimate of the exploration effectiveness and on the exploration budget determines the optimal time to be spent in each region.

Jan 1, 1986