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By J. F. Peterman, M. C. Roberts

The success of any industrial mineral project requires an accurate forecast of the demand fir the material as well as accurate projections of costs and prices. This paper develops a general method of predicting mineral requirements and applies it to the case of graphite. The basic method is to explain graphite consumption in each of its major uses by the output and manufacturing technology of the using industry. Once these underlying factors are determined, they can he projected to establish future requirements. This forecast is critical to the evaluation of a new source of supply, such as the graphite resources of Upper Michigan.

Jan 1, 1990

By M. J. Virnig, Marc Le Vier, Rong Yu Wan, Jan D. Miller

Although most gold production from primary resources is achieved by cyanidation, many research activities have focused on alternative processes using noncyanide lixiviants. Such research has been prompted by environmental concerns and problems associated with the processing of refractory gold ores. Numerous research projects have been conducted to search for a noncyanide hydrometallurgical process for gold extraction. In this paper, a technical review of gold recovery from noncyanide solutions is presented, and new results are reported. Gold recovery techniques that are considered include activated carbon adsorption, cementation, solvent extraction, ion exchange, and reduction-precipitation.

Jan 1, 1993

By G. Rinelli, Arthur F. Colombo, Donald W. Frommer

With the opening of the Tilden mine near Ishpeming, MI, a new era in iron ore beneficiation was begun. A description of a U. S. Bureau of Mines investigation is summarized to illustrate the selective flocculation-deslime-flotation process developed by the Bureau and used at the Tilden concentrator, which is also briefly described. The operating parameters for the selective flocculation-cationic flotation of an oxidized taconite from the Mesabi range are discussed. A water reclamation system using lime and a cationic flocculant was applied to reclaim the effluents from a 900-pound-per-hour flotation pilot plant. About 80 percent of water requirements were recovered, and the calcium content of the reclaimed water was found to be more important than clarity in influencing the selective flocculation and flotation processes. Although reclaimed waters with about 10 ppm calcium registered turbidities of approximately 5,000 ppm SiO2 equivalents, the concentrates produced using these waters contained 64 percent Fe and =5.0 percent SiO2 and had accompanying iron recoveries of 75 percent. Lower grade concentrates resulted from using reclaimed water with higher calcium contents and lower turbidities.

Jan 1, 1976

By W. B. Greer, J. J. K. Daemen

Introduction The performance of seals in boreholes, shafts and tunnels is an important concern in mine safety, in the control of effluents from operating and abandoned mines and in the underground containment of hazardous wastes (Einarson and Abel, 1990; Mining Waste Study, 1988). Despite the clear need for effective seals, few documented test results are available concerning the performance of in situ seals. Some evidence indicates that horizontal or near-horizontal holes are especially difficult to seal properly (Kelsall et al., 1982). This research involved the installation, extensive hydraulic testing, removal and post-test examination of a 10-cm-long x 10-cm-diam cement grout seal in a near-horizontal borehole in limestone. The work was performed in an underground mine on Marble Peak in the Santa Catalina Mountains, AZ. A test hole was diamond cored in the recrystallized limestone of the Escabrosa formation. The hole is 33.24 m long, 10 cm in diam, and dips at 10.4°. The hole extends between two drifts and thus is accessible from both ends. Seal installation Surveys to assist in selecting the interval to seal consisted of core logging, video logging and constant-head injection tests using a straddle-packer unit. The location selected, 3 m from the lower end of the hole, had low hydraulic conductivity (3 x 10-10 to 3 x 10-9 cm/sec) and was free of significant fractures. The grout used, an expansive Class A cement, was provided by Dowell-Schlumberger, Tulsa, OK. A grout mass about 1.5 m in length was installed, with a dump bailer, above a temporary mechanical plug. Groundwater in the hole, if any, was minimal during placement. After 13 days of curing, the grout mass was partially drilled out from both ends, leaving a seal 10 cm long. Water distribution in rock mass The distribution of water and fluid pressure in the rock mass near the seal appears to be complex. The generally dry condition of the borehole and rock mass suggests that the rock mass near the seal was unsaturated prior to the injection tests of this research. The injection tests presumably created an expanding saturated zone around the seal. However, anomalously high fluid pressures, consistently recorded by one of two piezometers installed near the seal, suggest connection to a source of significant natural hydraulic head. Comparable head variations for closely spaced piezometers have been reported by others (Sowers, 1976). [ ] Seal testing The seal was tested for 3.5 years, using steady constant-head, tracer travel-time, dye-injection, head-buildup and transient constant-head tests. These tests are fully described in Greer and Daemen, 1991. In the head-buildup test, transient flow occurs through the seal (and rock mass) to a closed, water-filled interval of the borehole adjacent to the seal. The test consists of monitoring the rise in head in the closed interval until steady conditions are approached. The test may be analyzed in terms of a one dimensional analytical model to obtain the effective hydraulic conductivity (Ks) and specific storage (Sss) of the seal. Analysis in terms of an axisymmetric three-dimensional numerical model may yield properties of both the seal and rock mass.

Jan 1, 1993

By Kugan Kuganathan

Pastefill is being increasingly considered as a viable fill by underground mine operators. Mount Isa Mines (MIM) chose pastefill to fill their deep copper mine (>1200m deep) after considering various other types of fill in the feasibility studies. During the development of pastefill at Mount Isa (1996 - to date) the Mining research of MIM developed two cost effective, reliable and simple testing methods and used. With the help of these tests the behaviour of MIM pastefill was studied thoroughly and the most optimum mix design for pastefill was achieved. The MIM's pastefill plant, the largest in the world with a capacity of 450rph continuous pastefill production and unique in the process used, has been built (1998-1999) to produce pastefill to the specification developed through extensive testing program using the Flow Cone and Mini Slump cone Tests. As a consequence, it is now possible to select the optimum pastefill mix designs and predict their flow behaviour in bore holes or pipe lines using only these tests. MIM Blended Tailings Pastefill (BTPF) uses 3-3.55 Portland cement and the cost of pastefill is much lower than the total tailings pastefill, that could be produced from the same tailings.

Jan 1, 2001

By Steve Skelhorn, Dan Ifrim

"A tunnel project poses many challenges; the operation of the Tunnel Boring Machine (TBM) being one of them. Mechanized tunneling is known as a safe and effective alternative to other methods in terms of schedule and cost; however, efficiency can be severely affected by a bad TBM selection and qualification and employment of inexperienced operators. The success of a mechanized tunneling project involves a comprehensive and interdisciplinary consideration of all contributing factors such as TBM technical specification and selection, TBM design and procurement including ancillary equipment and tunnel linings. The tunnel equipment selection along with the operation can make or break the project. The objective of this paper is to address the importance of the skills and qualifications of the TBM crew with particularity to the TBM Operator. The study includes the Owner and Consultant involvement in the selection and pre-qualification of the TBM crew and specifically the TBM operator as well as the role of Contractor and TBM manufacturer in TBM operator training. This paper also analyzes the possibility of issuing a TBM operator certification, and discusses the benefits and significance of periodic training and certification programs. INTRODUCTION Training in the tunneling industry is not a new topic. The industry continues to evolve and become more complex with technology advances and expansion of mechanical tunnelling to mechanized shaft construction, large diameter drilling and mining industry applications. The need for professionals trained to operate mechanized tunnelling equipment is ever increasing, while there is a significant number of veterans who will be ageing out in the next 5 years. Consequently attracting young professional is a very important aspect of sustaining a qualified pool of professionals. For any given tunnel project, the owner and the engineer spend up to several years, studying the ground conditions during preliminary and final design. Post contract award the contractor spend additional months studying the ground again to develop the optimum means and methods for construction. All this time and money spent at the beginning of the project has the purpose of developing the optimum tunnel design, assessing the risk associated and implementing mitigation measures to reduce risks to acceptable levels. Following the tunnel design process, sophisticated TBMs are being specified and sourced to ensure the best tool for the job. The question raises here: Are there available experienced/trained professionals capable of operating these sophisticated machines?"

Jan 1, 2016

By F. F. Aplan, T. H. Wentzler

Limestone is potentially a low cost material for the neutralization of acid mine drainage and other acidic waters such as steel pickling liquor. Unfortunately, when limestone is reacted wit9 these waters containing large amounts of Fe , Fe+3, and SO4-2 , a coating of gypsum and iron hydroxides form on the surface of the limestone inhibiting further neutralization reactions. The nature of these coatings, their morphology, composition and thickness were evaluated using the scanning electron microscope and microprobe, and the kinetics of limestone dissolution was studied both in the presence and in the absence of the reaction-inhibiting coatings. These data were then correlated with the solution chemistry.

Jan 1, 1992

By F. L. Wilke

Underground mining is a very complicated and complex industrial activity. The uncertain and, in most cases, the incomplete knowledge of the geological and mineralogical nature of the deposits can cause unforeseen difficulties. For a safe and uninterrupted operation, in addition to good planning and scheduling, reliable and up-to-date monitoring and control of all processes and conditions become necessary. Today, this is even more important in view of increasingly difficult working conditions, poorer grades, and more complex and expensive machinery. In short, large capital investment and higher risk of financial losses are involved in modern-day mining operations. Monitoring and control of the underground mining process has become a very complex and difficult task in itself. Many different systems are available, and the correct choice .is of utmost importance from both the economic and safety points of view. This chapter will deal with aspects of underground production monitoring and control. There are, however, many other areas of equal importance which are covered in an excellent manner in a hand- book by Olaf (1976) on monitoring and control of underground operations.

Jan 1, 1979

By John C. Draper

The principal object of an underground coal mine transportation sys- tem is to move coal from the face where it is produced to the outside of the mine where it is prepared for market. In addition to the movement of coal, a transportation system must also move supply materials to the inside; it must move men in and out of the mine; and it must move rock and other debris out of the mine for disposal. Usually, mine haulage is divided into three categories named for the various areas of the mine served : 1) Pace Haulage. This is used at face from the mining machine to the intermediate transport system. 2) Intermediate or Secondary Haulage. Generally this is used between face haulage and main haulage. Sometimes this is merely an extension of the main haulage. 3) Main Haulage. This extends from the secondary haulage to the outside and is usually either a track or conveyor system, sometimes a combination of both. Transportation modes of coal in the various areas pose different problems, but the whole system must be synchronized. For instance, at the face the coal should be removed quickly from the various places to facilitate the movement of machines, whereas the intermediate system just passes the same coal on to the main transportation system. Selection of the transportation system must be based on the seam height, mining methods used to extract the coal, capacity required, ease of coal handling, and haulage efficiency. When driving rooms, mine cars can be used. They often simplify supply haulage and rock handling because they can also handle these items. Conveyors could be used and would have a greater haulage capacity but they cannot handle supplies easily or segregate the rock. When using a different mining method, such as longwall, mine cars cannot be used because there is not sufficient space to move the cars at the face nor can the cars haul the coal without delays which would cause excessive losses in production. As for ease of handling at a longwall face, conveyors are convenient because of their low height, ruggedness, and ability to operate while being advanced. Similarly, in low seam heights, conveyor systems are easier and more economic to operate than the regular track haulage because roof has to be taken down for handling mine cars of adequate size.

Jan 1, 1981

By J. A. Reizes, C. A. J. Fletcher, T. Jancar

Spirals play an important role in fine coal and mineral processing. To date, almost all spiral designs have been empirically based. Although many operational units have evolved utilising this approach, it does not necessarily lead to optimal spiral designs. This paper presents the preliminary results of a collaborative computational and experimental research program to understand the detailed separation process which will ultimately lead to a parametric assessment of alternative spiral designs through computational simulation. Unlike the empirical approach, a computational simulation is only subject to the fundamental physics of the fluid flow. No prior knowledge of the generic spiral flow is necessary. The computer code implements a robust finite volume technique to predict the three dimensional fluid motion. A height function method is used to model free surfaces and the code is capable of handling arbitrary spiral geometries. Preliminary validation of the computational simulation is carried out through analysis of an existing spiral design -the Mineral Technologies LD9 unit. Computational flow predictions are compared with experimental measurements obtained using a number of techniques, including sampling and flow visualisation, for flow test cases where no solid particulate is present.

Jan 1, 1995

By Norman Miskelly

Substantial progress has been made over the last ten years in the development of uniform national and international standards covering the definition, estimation and public reporting of mineral resources and mineral reserves. Agreement between the major participating countries has been reached, which include the requirement that a Competent Person prepares and approves publication of mineral resources and reserves. Most national regulatory organizations have accepted the new standards and have included them in the rules that must be followed by mining companies operating under their jurisdiction. These developments are the result of a concerted effort on the part of professional societies, national regulatory agencies, international organizations, and many dedicated individuals. The historical development of these standards is summarized in this paper. Accepted definitions of mineral resources and mineral reserves are discussed, as well as the definition and role of the Competent Person. Additional effort is needed before the international standards are fully understood, accepted and followed by mining companies, regulatory agencies, the investment community and the general public. Steps being taken toward development of a Mineral Reserves International Reporting Code Template (International Template) that will be available for all countries to use in deriving their specific country reporting codes, are outlined

Jan 1, 2003

By D. Nilsson

This paper demonstrates the importance of including a discount rate in the determination of the optimum final' depth of an open pit. Without a proper discount rate, a pit will probably end up too deep. Another consideration is future underground mining. If underground mining is profitable, the pit may need to be shallower. Of all of the investments needed, only mining equipment and the underground mine should be included, and amortization and depreciation should not he included in the study.

Jan 1, 1997

By W. A. Lawruk, L. J. Wilson, D. E. Stief

The Tower mill is a vertical stirred mill using steel balls or pebble grinding media. This device is designed for fine grinding at significant power savings when compared to conventional tumbling mills. This paper describes the machine and its operation, application, and performance for wet grinding.

Jan 1, 1988

By Paul F. Richardson

Liquids containing suspended solids are encountered in most mineral processing applications. Solids levels cover a very wide range, from ppm levels in cooling water systems to slurries containing greater than 70% solids. When the aqueous phase is recycled or further processed, a solid/liquid separation process is used. Chemical additives used to carry out this process are called coagulants and flocculants. In other cases, one seeks to control or modify the properties of the suspension. Dispersants are chemicals used to aid in suspending solids in a liquid as well as to control the properties of the resulting suspension. Dispersants find a range of uses in mining and mineral processing such as scale control, filter aids, flotation aids, and slurry viscosity modification. Materials used as dispersants include inorganic salts, alkalies, organic surfactants, and polyelectrolytes. This paper discusses the use of dispersants in mineral processing, with an emphasis on control of slurry viscosity. The mechanism of dispersion and factors that affect the choice of dispersant will be discussed.

Jan 1, 1986

By Martha McJunkin, Lawrence Pietrzak

This paper describes and demonstrates the application of systems analysis and mathematical modeling techniques in the planning of actual tunnel projects and research and development to improve tunneling techniques. A recently completed tunnel project located in Utah is used as an example. Although cost estimating computer programs are used in tunnel project planning, the introduction of performance modeling, simulating the time to excavate, has added advantages that are explored here. The performance/cost tunneling model (TM) described herein mathematically simulates on a high-speed digital computer the important activities of a number of tunneling techniques accounting for activity interactions, variable external environments, mechanical failure, and other uncertainties. A cost accounting segment is included to facilitate cost-effectiveness comparisons. It is shown that, when combined with informed judgment and appreciation of limitations, the TM can be a useful tool that may help improve tunneling operations and cost estimation, for example, by achieving more balanced system designs or bounding the performance/cost implications of geologic and other uncertainties. Ultimately, this might lead to more competitive bids and greater profits. The need for systems analysis and modeling in tunneling research and development (R&D) is well recognized and documented.(1-5) In R&D one must seek broadly useful solutions to the basic problems of face fragmentation, materials handling, ground support, and environmental control. These solutions must take account of the interdependence of these elements and, for a variety of ground conditions, the limitations or constraints that any innovation in one element may impose on total system performance and cost. In this regard the structure and logic of the TM has been kept as simple and modular as possible so

Jan 1, 1974

By Stanley M. Moos

In reviewing available vacuum filtration equipment in this paper, several types of filters have been included which are probably not familiar to operators in the mining industry. However, it was felt that these units might be of interest in the event that an application should arise for the filtration of a product in the future that does not exist today. In addition, exposure of our industry to equipment used in other industries might have a tendency to be thought provoking and perhaps lead to the development of equipment and/or applications in our industry which do not necessarily exist at this time. Most innovations in filtration equipment have been confined to the improvement or design change of components and accessories, particularly reflecting the availability of materials of construction that have been developed. Recent developments in the application of horizontal belt filters have been innovative. The application of this unit as a substitute for or an adjunct to thickeners in a CO circuit can certainly be innovative and perhaps provide a basis for reduction in capital and operating costs in this area. For example, mill tails are generally pumped at the highest possible density that will adequately flow. Tailings ponds and dams with their attendant design requirements are based upon this estimated water volume. Availability of a much dryer, non-flowing filter cake opens up several new options for disposal. Considerable cost savings could result in the design and planning of disposal areas for containing dryer material. . No attempt has been made in this paper to provide a manual for the operation of all of the many types of equipment that are available. Rather, the paper tries to present an overview.

Jan 1, 1978

By Harrison H. Roberts

A. We are aware that many who are in the audience have perhaps heard before some of the material which will be presented. Since our firm is more closely associated with the heavy construction industry our experience is more oriented in that direction. Notwithstanding this, the subject your program committee has asked us to present centers mainly in the earth-moving field. We find a common denominator between say, the stripping of a site to uncover an ore-body which will be developed by open-pit methods, and that of excavating & transporting materials for an embankment dam, airport or other project. Both are earth-moving problems and we offer for your consideration a means of determining the most favorable method, equipment selection and resultant cost. We do considerable studies involving rock excavation for tunnels, underground powerhouses, inclined and vertical shafts for penstocks, muck-removal, electrical cable & other related underground work. Hence, we believe we speak the same language.

Jan 1, 1972

By Frank L. Gaddy

Falls of roof account for over 50% of the fatalities that occur in coal mines in the US. Thus, roof control is one of the more important phases of underground mining. In reality, the control of roof influences the system of mining and is a major determinant of the width and spacing of working places, operations at the mining face, ventilation control, and surface subsidence. Frequently, the control of roof is the largest single cost item. Roof control is a never-ending task, not only at the working face and throughout sections where men are working, but along haulways and air- ways that must be maintained for the life of the mine. This is because roof, even the best of roof, slowly deteriorates, so it must be frequently examined, with corrective support applied when needed. As coal is excavated, stresses are set up in the roof because the previous equilibrium is upset, resulting in pressures that cause fractures and slight movements that are frequently hard to detect. Unless the immediate roof, in the excavated area, is given support by artificial means, it might fall or there might be a succession of falls, varying from a thin scale to several feet, depending on the nature of the top. Exceptions to this are those rare mines, or sections of mines, with hard, strong, nonweathering roof that requires no support.

Jan 1, 1981

By D. R. Nagaraj

Based on our finding that commercial copper chelating solvent extractants such as LIX65N® and LIX63® are excellent collectors for copper minerals, a detailed study was made using several water-soluble chelating agents belonging to the class of aromatic hydroxyoximes and having a gradual structural variation. A basic study of the system salicylaldoxime-tenorite was also carried out. Microflotation tests as a function of concentration of oxime, pH, addition of copper etc., using oxidic copper minerals such as chrysocolla and tenorite, and batch laboratory flotation tests using synthetic mixtures of quartz and oxidic copper minerals were carried out. The studies were aimed at an understanding of the collector function of the hydroxyoximes and of the general flotation behavior in these systems, in addition to studying the structural aspects of oximes vis-a-vis flotation. The results have demonstrated that all of the hydroxyoximes studied here have comparable collector property, and in all cases the oxime was found to be partitioned between the mineral surface and the copper in the bulk aqueous phase in the form of a bulk copper chelate. The occurrence of the latter could be accounted for by the formation in the bulk phase of a chelate between oxime and copper released from the mineral and/or by the detachment of the surface chelate. The role of surface and bulk chelates in flotation is discussed based on the results of partitioning of chelating agent into bulk and surface chelates in the system salicylaldoximetenorite. The effect of substitution of CH2 groups or benzene ring in the chelating agent molecule on its collector property is also discussed, in addition to the finding that only the anti-isomer has the ability to collect.

Jan 1, 1979

By K. F. Jakob

Sustainable development is a principle for the way we should act in the present. It ensures also options for the future to achieve a balance between social, economic and ecology development. The efficiency of raw material utilisation is being enhanced through technological developments, starting from extraction through all the following stages of the value creation chain. The use of domestically produced resources helps to assure the technological know-how. Additional indicators being collected and published by individual companies are questionable in countries with a tightly regulated legal framework such as in Germany, but make sense in developing and threshold countries. Sustainability in terms of efficient use of raw materials will manifest itself at the next stages of the value creation chain. Examples for efficiency improvement can be found in the steel, the power generation and agriculture industries. The approval procedures for German mining operations entail an internationally extremely strict assessment of the potential impact on the environment. All the mining activities include remediation and recultivation where the practise in Germany has become model character by international levels.

Jan 1, 2005