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Ever since A Decade of Digital Computing in the Minerals Industry was published in 1969, mining men have expressed the need for an additional reference on computer methods. It was felt such a volume should spell out the "how to" of computer applications in the solution of their problems. Computers in the minerals industry will be 20 years old when the 1979 SME Fall Meeting and the 16th International Symposium on the Application of Computers and Operations Research in the Mineral Industry (APCOM) take place jointly in Tucson, AZ. On such an occasion it was thought appropriate to publish an anniversary volume which reviewed current practices and projected what might prevail as computer methods for the future. Thus was born the idea to publish Computer Methods for the 80's. The first planning meeting for this volume took place in Las Vegas, NV, during the 1976 annual meeting of the American Institute of Mining, Metallurgical, and Petroleum Engineers. It quickly became evident that no single computer method existed to solve most mining problems; rather, mining computer methods are generally tailored to fit unique geologic, mining, and organizational conditions. Hence a format which included both the theory and practice for each of the computer applications was adopted for this volume.

Jan 1, 1979

By K. Bragg

During the last several years considerable discussion has taken place on the long term aspects of uranium tailings management. These discussions have centered around a variety of topics which in turn lead to a variety of opinions. In order to come to grips with the various differences of opinion and points of view, the Atomic Energy Control Board has decided to prepare, as an interim measure, a list of proposed close-out criteria for uranium tailings management facilities. It is important to keep in mind that the criteria set out in this paper are proposals and are intended to initiate a continuing dialogue between the uranium mining industry and the various regulatory and government agencies. It is envisaged that this dialogue would continue for a period of from six to twelve months after which some final form of these criteria would be issued and applied to the active uranium mining facilities. In attempting to understand the reasons why the Atomic Energy Control Board has decided to propose these criteria now instead of at some future point in time, it is necessary to look at a number of existing facts. One of the most important of these is that something in excess of one hundred million tonnes of tailings currently are placed in various tailings management facilities. Furthermore, the rate at which tailings are being deposited into such management facilities is on the increase and this increase is expected to continue over the next five to ten years. The management of these tailings is currently covered under the Mine Facility Operating Licences issued by the AECB. Implied within these licences and supporting documents leading to them, are requirements for the conceptual approach to be used at abandonment. There is however, no current requirement for a detailed study on the engineering or financial aspects of such abandonment procedures. This is a gap which the Board feels must be addressed. There are, at this time, various initiatives underway both in Canada and within the international community which are attempting to address the problems and concerns of the very long term management of tailings. For example, current research in Canada which is composed of two components, one by the AECB dealing with purely regulatory aspects and a second major coordinated program under the direction of the Department of Energy, Mines and Resources and in particular by CANMET is going to deal with the technical problems. On the international scene

Jan 1, 1980

By Keith S. Liddell

he selection of mill design parameters to suit the applica­tion requirements can result in quite different operating parame­ters for each generic type of application, even though the basic mechanical layout of the mills may remain similar. The selection of the type and size of grinding media is very important to efficient and cost-effective operation, and to ensuring that the milled product achieves the required properties. Accordingly, the grinding media selection is seen as an integral part of the mill design. Consideration of the requirement for classification is important in order to achieve the optimum mill and circuit performance. This can lead to the circuit feed not being classified for a steady feed with minimal slimes and a low size reduction ratio. Feed containing on-size particles would be deslimed by open circuit classification. Closed circuit classification is performed where the feed fluctuates. The rheological characteris­tics of the circuit feed slurry can have an influence on mill performance, and needs to be allowed for. A common misconception frequently encountered is the belief that "a mill is just a mill". This is not the case with stirred types of mills, since the operating parameters selected for the mill can have a large effect on the product characteristics. For example, horizontal shaft high speed stirred mills have a com­pletely different grinding action to vertical shaft low to medium speed stirred mills, which results in large differences between the surface area produced at a given product size (Liddell, 1986). Hence, it can be misleading to apply test results or design procedures obtained from one type of mill to other types for scale-up. The Metprotech stirred mill, as applied in the mining and minerals industries, is a low to medium speed vertical shaft mill. The basic design has been discussed previously (Liddell, 1989). Currently, the largest mills that have been manufactured have an installed power of 400 kW. The largest chamber volume at this power is 6000 litres, containing IO t of grinding media. It is intended that the installed power will increase up to lMW as applications requiring larger sizes arise.

Jan 1, 1995

By J. Mark Richardson, Mary S. Sredanovic

The use of computerized steady-state process design balance systems has reduced engineering man-hours by as much as 80 to 1 over conventional manual balance calculations. The popularity and widespread use of such systems by the minerals industry increased dramatically in recent years, but these systems were mainly available for use on large main frame computers and lacked graphic capability. A considerable amount of engineering manpower was required to "conceptualize" a process flowsheet. After sketching the flowsheet layout, the engineer was still faced in most cases with a time-consuming reduction of his graphic concept of the problem to numerical data required by the balance program. Furthermore, output from these early systems was usually in tabular numeric form. The computer results then were transferred manually to a pictorial representation of the process. A new process design balance system has been developed which runs on a popular and inexpensive personal computer. This system combines modern Computer Aided Design (CAD) principles and the graphics capabilities of the personal computer to allow the process engineer to define a flowsheet problem while creating a process flow diagram. The system provides balance results in both pictorial and tabular form. Past, present, and potential applications of the system are discussed, and an analysis of the cost benefits derived from its use are provided.

Jan 1, 1985

By Hu Wenjun, Li Maonan

Mine ventilation systems mostly are ventilation networks with fixed-quantity branches. The solution to the problem of ventilation networks with fixed-quantity branches is obtained by choosing the fixed quantity branches as chords and using Hardy Cross iteration method. The solution usually is feasible but may be not economical. This paper takes minimal annual ventilation electricity cost as an object, considering the power of main fans and boosters, natural ventilation pressures and resistances of regulators, and builds up a nonlinear programming model. A set of initial values of the nonlinear programming can be obtained by using Hardy Cross method, The MAP technique then used to find a set of local optimal solution The running procedure with a simple example is dicussed. Mine ventilation systems mostly are ventilation networks with fixed quantity branches. In the networks, air quantity of branches are generaly regulated by increasing branch resistance or air pressure. A comon approch to the of the networks with fixed quantity branches is to formulate it based on Kirchhoff's current and voltage laws and the solution is obtained by Hardy Cross iterative technique. The solution usualy is feasible but may be not economical. The optimal plan of air quntities regulation of mine ventilation network should be to make the solution satisfy both required quantity of work places and minimal ventilation operating cost. It is the purpose of this paper to introduce a new approch and computational experience of nonlinear programming of the optimal problem.

Jan 1, 1991

By C. C. Huang

Rare earth compounds, such as samarium-cobalt compounds and neodymium-icon compounds, are being used more often for the manufacture of permanent magnets, because these materials permit the production of permanent magnets with higher magnetic energy potential than the conventional ferrite magnets. Especially, the recent rapid developments in the field of electronics and electro-technology have demanded an increased production of rare earth magnets. Unlike ferrite, which is typically produced by a wet process, rare earths can be ground and classified either in a wet or dry process. In the past, batch ball mills, through-pass ball mills in circuit with air classifiers, and conventional jet mills were primarily employed for the dry processing. These methods, however, have suffered from the problems, for example, wear and contamination, low product quality In particle size distribution, difficult to adopt inert-gas operation, and high specific energy consumption. In this report, dry processing of rare earth powders will be presented, especially ultrafine grinding with fluidized bed jet mill.

Jan 1, 1993

By H. Wu, V. Izaxon

Intensive ventilation is required during the excavation of a mine opening and the subsequent exploitation of the mineral resources. The exchange of heat between the ventilation air and the rock mass has a major influence on the thermal regime of a mine, especially in the initial segment of the airway. In frozen ground, heat flow into the rock mass from the ventilation air can result in the eventual thawing of the permafrost, which can result in roof-rock instability. This paper presents a mathematical analysis of the dispersion process of ventilation-induced heat by thermosyphons placed on the surface of the mine. The principal uses of thermosyphons in the Arctic are to reduce the ground temperature to prevent potentially unstable permafrost from thawing and to increase the bearing strength of the material. The mathematical model of the physical problem, generally known as "the Stephan problem," takes into account the varying thermo-physical properties of air and the frozen and thawed rock mass, the thermal properties of the freeing fluid in the thermosyphons and the phase change of water. Finite-difference techniques were employed to determine the temperature isotherms around the thermosyphons. It was found that two rows of thermosyphons on a 10- x 10-m grid provide an acceptable design spacing for reducing the ground temperature around the mine airway.

Jan 1, 1997

By A. S. Polubinsky, V. P. Chernyak

A further development of the theory of heat- and mass transfer in the system “strata - mine opening" is necessary for an improvement of the existing technique of heat calculation of mines and other underground constructions. A generalized boundary problem of heat- and mass conduction in strata around an opening as a theoretical ground for that purpose and several particular situations, important from the point of view of an opening and surrounding strata heat state analysis, as well as results of numerical experiments executed for such analysis are presented.

Jan 1, 1997

By William J. Miles, Raymond E. Blair

Introduction There has been much publicity of the boom and bust in oil and gas well drilling in the US, and many comments on oil and gas gluts. Despite this, the drilling industry remains the largest consumer of functional industrial minerals. The boom years of 1981 and 1982, compared with the bust year of 1983, show a sharp reduction in the consumption of industrial minerals-1981, 7.4Mt (8.2 million st); 1982, 6.3 Mt (7 million st); and 1983, 4.4 Mt (4.9 million st). Industrial mineral use rebounded in 1984 to 4.7 Mt (5.2 million st). This was the second highest year in history in terms of wells drilled and third highest in footage drilled. Table 1 shows the history of drilling activity and mineral consumption from 1971 to 1984. The uses of functional industrial minerals in oil and gas well drilling were detailed by Miles and Blair (ME, 1983, October, pp. 1397-1400). As an update, this article addresses only the changes that have occurred in the industry in the past two-and-a-half years. It will be directed to mineral use and new products introduced to the industry. Drilling practices A partial explanation of where wells are being drilled with lower quantities of minerals consumed is: • In the boom year of 1981, there was a proliferation of number of suppliers chasing the same business. This resulted in multiple sourcing, multiple warehousing, and a huge increase in inventory that became surplus in the following years. The bust year, 1983, caused a severe shakeout in the number of suppliers of minerals and associated drilling fluids. • In 1981 and 1982, the wild speculation in the oil and gas industry led to drilling of speculative deep gas wells. Oil wells were drilled on a wildcat basis - in areas of unproven productivity. • Presently, the oil and gas well drilling industry is very active. But drilling is directed toward proven areas of production and working over old wells for increased production. This means a large number of wells are being drilled with lower average foot-

Jan 11, 1985

By P. Venkatasubramanian

The aerospace and nuclear industries have been applying systematic techniques for assessing the safety of complex technical systems for many years. These techniques such as fault tree analysis, failure mode, and effect analysis, etc., and more recently "expert systems," were developed to formally evaluate systems safety and to determine how hazards can he reduced. The application of formal methods such as expert systems has the potential for further reduction in both frequency and the consequences of mine accidents. This paper presents a general expert system model of diagnostic reasoning and describes its use as an inference method for analysis and problem identification for accidents due to the presence of an open cycle diesel-powered mine cars in underground coal mines.

Jan 1, 1987

By John F. Slonaker

This report is a review of current research being conducted in the United States which is intended to increase the utilization of coal ash. In order that this report be as timely as possible, the majority of information was obtained by direct comunication with the people listed in the references. Due to the magnitude of the flyash research program, some projects may be inadvertently omitted. Field research on flyash for use as an agricultural fertilizer is being monitored at Virginia Polytechnic Institute and State University.1 This research is directed at determining the plant nutrients that are available in flyash as well as the quantities of flyash that can be applied to agricultural soil without adversely affecting plant growth, Coal mine spoil and refuse bank reclamation with power plant flyash is being demonstrated by United States Bureau of Mines, Morgantown, West Virginia.2 Numerous highly visible coal refuse piles and strip mine spoil banks contribute to air, water, and land environmental problems. Revegetation of several experimental sites with flyash from bituminous coal-fired power plants was undertaken in West Virginia and Pennsylvania. Conventional farm equipment was used at some of the sites while large earthmovers were required at others. The flyash served as a neutralizing agent, dilutent, and soil amendment to provide some nutrients which enhanced vegetation of the barren areas, Estimated cost of reclamation by this method is $300.00 per acre of previously leveled area. This figure can vary considerably depending upon the topography of the site, haul distance, quality of the soil and quality of flyash.

Jan 1, 1974

By Dr. Richard F. Coon, James D. Mavis

Risks and abatements associated with preliminary reconnaissance, plugging and filling, and maintenance of perched mine water pool are examined. This case history showed that the initial appeal of portal plugging was replaced by concern over potential environmental hazards when details of implementation were investigated.

Jan 1, 1992

By C. P. Newman, T. Gray, G. Beale, T. Cluff

Predictive geochemical and limnologic modeling of pit lakes is an important aspect of modern permitting. One of the key assumptions of many predictive pit-lake models is that highwalls and pit backfill become unreactive once submerged by the filling pit lake. Existing pit lakes provide useful data to test this assumption. The Sleeper pit lake (northwestern Nevada) is near hydrologic equilibrium and contains good-quality water that generally meets regulatory requirements for pit lakes. Despite the overall stable geochemical composition, seasonal trends in the hypolimnion indicate the generation of solutes and fluctuations in pH. This work applies mass balance, analysis of subaqueous pyrite oxidation, and trends in solute concentrations to evaluate the potential causes of long-term solute generation in the hypolimnion of the Sleeper pit lake. Results will aid in refining the effect that inundation of highwalls and waste rock has on ultimate pit lake chemistry and long-term closure planning. In the case of the Sleeper pit lake, ongoing solute loading does not substantially change the closure plan at this time as influent groundwater contains abundant alkalinity. INTRODUCTION As mine pit lakes become more widespread, regulatory agencies are increasingly requiring advanced predictive modeling of pit-lake geochemistry during permitting. The end goal of all those involved in these permitting actions (i.e., the mining company, the regulatory agencies, and the public) is to have pit lakes become geochemically and hydrologically stable for the long term, which may then allow mining permits to be relinquished. The modeling endeavors therefore are important to inform long-term closure of pit lakes. The conceptual models and numerical methods used to predict pit-lake water quality are complex and require substantial amounts of data and a variety of assumptions (Castendyk et al., 2015). One of the common modeling assumptions is that solute generation via acid mine drainage is eliminated (or at least decreased) by the filling of the pit lake and inundation of highwalls and any in-pit waste rock. However, few studies have reported on observations that support or refute this assumption. The water-quality record of the Sleeper pit lake is an ideal dataset with which to test these assumptions. The former Sleeper mine is located in northwestern Nevada (Fig. 1), and has been inactive (in terms of ore extraction) since 1996. The mine extracted Au and Ag from the famous high-grade Sleeper vein and associated widespread stockwork mineralization (Nash et al., 1995). Water quality in the pit lake has been monitored since the cessation of dewatering in 1996. The current pit lake actually occupies three separate sub-pits, the Sleeper, Wood, and Office pits (Fig. 1). The Sleeper and Wood pits undergo regular water-column monitoring using a conductivity-temperature-depth (CTD) probe, and sampling for dissolved inorganic constituents at several depths (~10, ~130, and ~330 ft. below lake surface). Groundwater quality is also monitored using a series of wells (Fig. 1).

Jan 1, 2019

By W. R. Boehme

The test work was done in two parts. In Part I, five 6 x 16 mesh activated coconut shell carbon samples made by four different manufacturers were evaluated as to their gold loading rate and total gold loading. The five carbon samples tested are not identified by manufacturer and are simply designated as Types A through E. Then from the carbons tested, a suitable highly active carbon was selected for subsequent studies on impurity effects upon loading, Part II. Test Procedures The procedures and tests descriptions are given for the ultimate gold carbon loading tests and the dynamic gold carbon loading tests.

Jan 1, 1983

By John A. Rajala

The water chemistry of the froth flotation pulp is one of many parameters which can affect the flotation process. The fluid may contain certain inorganic salts which, along with increased ionic strength, can produce undesirable flotation depression or activation. A source of a salt could be the use of calcium chloride to prevent freezing in ore cars, chutes, and bins (Anon., 1980). Alternately, the salt or salts could be initially contained in the water as in the case of sea water and some brackish waters. These salts may become more concentrated because of the need for recycling of plant water due to environmental regulations and/or economic considerations (Davis, F.T., et. al., 1976). The presence of inorganic salts in flotation pulps and their effects upon the recoveries and surface chemistries of different oxide minerals have been the object of various studies. Some researchers (Fuerstenau, D. W. and Raghavan, 1976; Fuerstenau, D. W. and Modi, H. J. 1960; Kulkarni, R. D. and Somasundaran, P., 1977) have reported that addition of a salt can increase or decrease flotation recovery depending upon the particular system.

Jan 1, 1982

By P. K. Ackerman, F. F. Aplan, G. H. Harris, R. R. Klimpel

Fourteen reagents that are potentially capable of chelating with a metal ion on the surface of the major copper sulfide minerals and pyrite were evaluated for their effectiveness in floating these sulfides. The reagents studied fall into the classes of mercaptobenzole mutations, thiouronium, thionocarbamates, thiourea, imidazole mutations, oximes, hydroxyquinoline and xanthogen formate. The best overall copper sulfide collector was an imidazoline (1-Hydoxyethyl - 2-Heptadecenyl), but it also proved to be an excellent collector for pyrite. Its potency as a pyrite collector can be reduced by structural alteration, but at some loss in its collecting power for the copper sulfides. The effectiveness of many of these potential collectors can be changed by minor alterations to the collector molecule and, to a lesser extent, by pH adjustment. The general order of mineral floatability with these reagents is chalcopyrite = chalcocite > covellite =bornite >> pyrite. The flotation of malachite is generally similar to that of the copper sulfides, indicating the special effectiveness of copper in the crystal lattice for collector attachment.

Jan 1, 2000

By A. M. Marabini, V. Alesse, Belardi. G.

An alternative flowsheet was designed for the flotation treatment of a complex sulfide ore from the Sotiel Mine in Spain. The ore contains 0.71% Cu, 2.24% Pb and 5.63% Zn. Two specially developed synthetic collectors, methyl-mercapto-benzoxazole (MMBO) and 6n-propoxy-mercapto-benzo-thiazole (PMBT), were examined. MMBO exerts a specific action on copper and zinc minerals after treatment with copper sulfate, and PMBT exerts a specific action on Pb minerals. Flotation operating variables (pH, frother type, frother quantity and feed particle size) were examined by means of rougher flotation tests to determine the optimum conditions for the new collectors. Once the optimum conditions were determined, a series of open flotation circuits were run on feeds of various particle sizes (obtained by different types of grinding). The objective was to obtain high-grade Cu and Zn concentrates. The results of the open-circuit tests demonstrated that a Cu concentrate grading from 18% to 23% Cu and a Zn concentrate grading from 40% to 48% Zn can be produced.

Jan 1, 1996

By E. Suoninen, K. Laajalehto, L. Kartio

Efficient separation of pyrite from other sulfides is of great importance for the metallurgical performance of flotation processes. In this work Fourier Transform Infrared Spectroscopy (FTIR) and X-ray Photoelectron Spectroscopy (XPS) were used to study the surface chemistry of pyrite in depression, activation and xanthate adsorption under conditions of controlled potential. Modifications of pyrite surfaces after treatment with depressants (lime, sulfur dioxide, sodium cyanide) and after activation with metal ions (Cu, Pb) were studied. The principal adsorption product identified on pyrite was dixanthogen whose formation started at about +0.15 V and +0.25 V (vs, SHE) in ethyl and amyl xanthate solutions, respectively. Copper xanthate was formed on copper(II) activated pyrite. Activation mechanism of pyrite by copper(II) salts is likely to be electrochemical where copper occurs as copper(I) on the surface of pyrite. Effective depression is achieved by sulfur dioxide and sodium cyanide. Depression at high pH is due to formation of iron(III) hydroxides. Calcium ions do not affect the electrochemistry but adsorb on pyrite and reduce the surface sites for dixanthogen adsorption.

Jan 1, 1995

By J. Derwin King, Harrison R. Cooper

Applications of nuclear magnetic resonance (NMR) offer possibilities for on-line sensing of the concentrations of several elements in flowing sample streams. In addition to hydrogen, these elements, generally of low-order atomic number, include aluminum, phosphorus, fluorine, sodium, boron, and lithium contained in minerals having commercial importance. Many such elements have been difficult or impossible to successfully measure on-line using the more familiar X-ray fluorescence and neutron activation analysis techniques. The availability of practical on-stream analysis methods is essential to applying advanced controls to processes incorporating these elements. On-stream NMR instrumentation has been demonstrated in the past for several process applications including, as an example, coal flow and analysis; and the technology has recently been extended to the measurement of phosphorous BPL in Florida beneficiation plants. The technique involves simultaneous sensing of proton (hydrogen) and 31P intensities to provide data for continuous calculation of BPL in the phosphate through calibration to volume fractions of water and solids. Initial operating results are described using the PhospholyzerTM on-stream phosphorous analyzer designed for plant application.

Jan 1, 1990

By B. Moudgil, Hassen El-Shall

Particle shape and size distributions are among the most important parameters that affect the filtration efficiency of phosphogypsum in wet- process phosphoric acid production. Cost-effective enhancement in filtration rate is desired by phosphoric acid producers for higher plant capacity and lower operating costs. In this regard, numerous research efforts have been carried out in different laboratories as well as in pilot and plant testing. Nevertheless, changes in phosphogypsum crystal shape and size distribution deserve special attention. In this study, the results obtained in the presence of Crysmod and Hiflo-S5 surfactants are discussed. The influence of such additives on crystal morphology and size distribution are studied under different sulfate contents (supersaturation). The obtained data are correlated with process efficiency parameters such as filtration rate, digestion of rock, and recovery of phosphate values. Up to 60% increase in filtration rate is obtained. In addition, an increase in digestion efficiency and P205 recovery is achieved due to addition of surface active agents. The observed beneficial effects are explained in the light of the changes induced in crystal habit, size, and size distribution.

Jan 1, 1999