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The request for proposal from the U.S. Bureau of Mines outlined the purpose of this study in the following terms. "High grade near surface deposits are largely a matter of history. Most of the current mineral production in the united States is from large low grade ore deposits mined by large scale methods. It appears likely that exhaustion of near surface deposits and public resistance to open pit mining will tend to reverse the present trend toward open pit mining and lead to increased reliance on large scale underground mining. In view of the long lead time needed to improve basic technology, an in-depth study of the major underground mining methods is needed. "This study is intended to provide a systematic review and analysis of large scale non-coal underground mining technology with particular emphasis on current practices and problems, needed technological improvements, existing or potential environmental conflicts, and possible modifications or innovations that will assist in the satisfaction of projected national mineral supply requirements."

Jan 1, 1974

By J. R. Maxwell

In 1970 expansion was completed increasing mill capacity from 2,000 to 3,000 T.P.D. Actual grinding capacity is 3,400 T,P,D. at a grind of 60% -200 mesh,The ore bodies are vein type, containing about 12% sulphides, with mill heads averaging 2.25% Cu, 0.015 oz.Au, and O.4O oz, Ag. per ton.Summary and Conclusions:During the period Jnnuar-1 1971 to December 1973 inclusive the use of large cells at Opeminka have shown that metallurgy is comparable to when using conventional cells, Operating and maintenance costs are lower, An on stream analyzer with reagents controlled by computer, are being assessed further.Opej1atljn Of Cells:!lo cell level adjustments are required when tonnage is adjusted 20 to 25%.Depending on mill heads and grade of concentrate reagents are adjusted to the first rougher for metallurgical control. Reagents to second rougher and scavengers are seldom adjusted as feed to this section has a maximum variation of about 0.2'~ Cu.Power – Maintenance and Space Requirement :Our total power consumption for 3,400 T.P,D. flotation circuit for operation and air supply is 280 H.P. Previous power drawn using conventional cells was 400 H.P. at 2,000 T.P.D.Total maintenance costs for flotation circuit has averaged $1,100.00 per year for the 3 years of operation, this cost should remain constant.Floor space required for cells and walkways is 2,000 sq.ft.

Jan 1, 1974

By C. E. St. Denis

"Training Program at Sherritt Gordon's Ruttar:. ConcentratorA formal training program for mill operators is being developed and employed at Sherritt Gordon's Ruttan Concentrator. The program was set up to fulfil the needs created by a shortage of skilled reliable labour, a 200% turnover of personnel within the first six months of operation and the rapid advances in mineral processing technology. All new employees are introduced into the Mill Department through an orientation program designed to familiarize them with the operation of the plant. All training and orientation of new employees is the responsibility of a. small training section consisting of two training foremen and one assistant. Using a combination of classroom and supervised on the job training, the training times have been cut by at least one half. High operating standards have been set and are maintained through the use of detailed manuals for each work area and competent instruction at all operating levels. The major portion of training costs arise from the salaries of the training staff but are negligible when compared to the improved recoveries, smaller turnover and less downtime. Government assistance is available to all industrial employers to offset the costs of training employees."

Jan 1, 1974

By R. D. Brown

"""A matter of serious concern to the mining industry in British Columbia""; this comment reflects the attitude of the Mining Association of British Columbia toward the proposed new B.C. Mineral Royalties Act. The proposed legislation, introduced by the provincial government in February and now being debated by the legislature, combines a basic 5% royalty on the selling price, less approved p1ocessing and transpo1•tation costs, of minerals produced in B.C. with an ""excess"" royalty of 50% of any price increases over a predetetmined base. Government estimates project annual revenues of $20 million from the new royalty structure. The accuracy of these figures has been contested by the mining industry. Based on current world prices for copper the industry estimates that the provincial revenues from this mineral alone may run as high as $140 million in 1974 and $150 million in 1975. The Mining Association has warned that the new royalties “threaten to become confiscatory""."

Jan 1, 1974

The considerations which led to the decision to_ install discs at the Dampier Pellet Plant of Hamer ley Iron Pty. Ltd. are described. Initial testwork showed that the ore could be ground dry in open circuit to a Blaine index of 2500 cm2/g and that it pelletized readily. The various design criteria including diameter, slope, speed, motor size, depth of sidewall, feed point and water spray location were then determined. Plant performance after commissioning is described including the various problems encountered and the modifications since carried out to overcome them. The main problem was quickly identified as disc feed rate control. Various bin and bin feeder modifications were tried to overcome the effects of the fluidising characteristics of the dry ground ore. Other factors found to affect disc operation are ore size distribution, additives and operator competence.

Jan 1, 1974

By G. Merle, David L. McKay, Elmar Randveer

"THE ENGINEERING AND TECHNICAL SERVICES department is responsible for supplying the following services:1. Administration and co-ordination of the work required for capital projects.2. Engineering, design and drafting services for inplant changes or improvements as requested by the operating• and maintenance departments.3. Rock mechanics.4. Preparation of plans and layouts required for efficient extraction of the ore as mutually agreed with the mine operating departments.5. Mine planning and long-term schedules in co-operation with the mine operating departments.6. Grade control (long term and short term) and the preparation of ore and waste removal schedules to maintain a uniform grade of mill feed. This also includes the calculation of metal reserves and metal production forecasts.7. Surveying, underground and surface.8. Operations research at the mine site.9. Industrial engineering.10. Chemical analyses and assays.11. Instrumentation.12. Environmental control.A staff of approximately 35 supervisors, engineers and scientists, and 80 technicians, supply the foregoing services. Consulting engineering and drafting firms are used to supply specialized services and technical personnel in-house at Timmins to handle overloads on capital projects under the direction of Ecstall engineers.The operating and maintenance departments depend on the engineering department to supply engineering, design and drafting services for any new facilities or for any planned alteration to existing facilities. To do this efficiently requires a high level of communication and co-operation with these departments. This has been a major factor in developing the present organization of the department shown in Figure 63.The organization is predicated on a strong central technical and engineering resource from which personnel can be assigned responsibilities for different projects, and in different areas, as the work load demands. Job satisfaction is very high because of the variety and challenge in the tasks. Additionally, participation in projects with production and maintenance personnel broadens each technical employee's knowledge of operating and maintenance problems."

Jan 1, 1974

By William S. Alldredge

The Washington Metropolitan Area Transit Authority(WMATA) officially came into existence in February 1967 after the District of Columbia, Maryland, and Virginia joined in a com¬pact pursuant to Federal creative legislation signed the previous November to build a regional rapid rail transit system called METRO (1). The parent organization was the National Capital Transportation Agency (NCTA), a Federal agency, subject to Federal statutes and regulations. Soon after the completion of the transition from NCTA to the new "non-Federal" status of the Authority, the Board of Directors of the Authority formally adopted procurement policies and procedures (2). These are specific statements concerning competition by formal advertising for bids or by solicitation of proposals for negotiation, contracting authority, approval of awards, awards of contract modifications, and processing of claims and disputes. These policies and procedures are silent as to Federal procurement statutes and regulations. But because of the Authority's origin, the sensitive nature of the compact among the several sovereign jurisdictions, Federal financing of two-thirds of the costs, and the resultant surveillance by the General Accounting Office over staff operations, the Authority's procurement practices follow closely Federal regulations adapted to WMATA's needs. This is an important point and is the foundation of contractual relations between the Authority as the owner and its construction contractors. Various constraints and flexibilities of this arrangement with respect to excavation and tunneling contracts will be pointed out in the ensuing discussions.

Jan 1, 1974

By Samuel S. M. Chan

The magnetic susceptibilities of some ores and the major rock formations of the Precambrian Belt Supergroup in the Coeur d'Alene mining district were determined both in the laboratory by the use of the Gouy method and in the field with a Bison susceptibility unit. Trace element analysis of the same group of rock samples was also made using the atomic adsorption technique. Results of this preliminary study indicate that some correlation exists between the magnetic susceptibilities and the various rock formations. This may be useful for regional mapping and mineral exploration.

Jan 1, 1974

By George S. Koch

A mathematical simulation model has been devised to guide the layout of underground mine workings, drill stations, and drill holes that are established in order to search for tabular ore bodies. Developed and tested for elliptical ore shoots in fissure veins in the Galena mine, Coeur d'Alene district, Idaho, the model can also be applied to ore bodies contained within sedimentary beds (for instance, many types of uranium, copper, and gold ore bodies) or other tabular structures. Programed for a time-shared digital computer, the model contains both stochastic and deterministic variables. Stochastic or natural variables include the number of ore shoots and their sizes, orientations, locations, and values. Deterministic or controllable variables include (1) locations and costs of workings; (2) drill-station locations and costs; and (3) drill hole azimuths, inclinations, lengths, and deflections, if any. For various assumptions about the stochastic variables, the model is run while the controllable variables are changed deliberately. Thus, layouts are devised to determine the percentages of the total number of assumed ore shoots found at different costs. In order to choose among the various layouts, cost-effectiveness measures are calculated.

Jan 1, 1974

By C. E. Gregory

In terms of a Research Proposals supported by a Grant Agreement dated 30 June 1973, the author was commissioned to prepare an annotated bibliography of mine fires. The main objective was to conduct a comprehensive program of library research and search of official files to prepare a list of articles dealing with actual occurrences of mine fires. This bibliography as now completed includes an annotated reference from each article or report cited, underlining the cause, extent, methods used, procedural errors made, results achieved, ventilation effects, and lessons learned from the operation of subduing the particular fire.

Jan 1, 1974

By Charles J. Haas

The objective of this research was to investigate the interaction phenomena of rock and types of rock bolts to develop design principals for using grouted roof bolts. The investigation was to determine the effectiveness of grouted bolts in resisting lateral displacement and axial separation along fracture planes, and also to determine if grouted bolts eliminate the axial tensile stress near the anchor and the resulting rock fracture. The first year's effort involved defining the post-tensioning response of grouted bars and determining the amount of shear resistance generated by conventional and resin-grouted bolts. A finite-element analysis showed that if the rock and resin grout behave in an elastic manner, the post tensioning of a grouted bar will affect mine roof stability only if movement occurs near the collar. An experimental shear test program revealed that both conventional bolts and resin-grouted reinforcing bars significantly increase shear resistance along fracture or bedding plane when the average normal compressive stress on that plane is low (in the order of 25 psi) and when the bolt is oriented so that the shear displacement tends to lengthen the bolt. An increase in shear resistance is also noted at the higher normal pressure of 250 psi; however, the increase is small compared to the corresponding shear resistance without a bolt. Conventional bolts oriented so that they tended to loosen with shear displacement added no significant shear resistance.

Jan 1, 1974

By William G. Hedling

The operation of electric face equipment in underground coal mines has proven to be extremely hazardous to mining personnel, including equipment operators and others working in the vicinity of active equipment. Recent industrial engineering studies* of accidents and fatalities indicate that a major contributor to this hazardous situation is noncompliance with modern principles of human engineering, particularly lack of standardization of control configurations. Control configurations differ not only among different machine types, but also among the same machine types produced by different manufacturers. This lack of standardization can produce a high incidence of error in the operation of electric face equipment, thus creating a potential source of accidents. Other examples of non-compliance with human engineering principles are the widespread use of identical black, round control knobs (regardless of the function being performed), and the inappropriate location, spacing, and labeling of controls. Any or all of these factors may place the operator in a "negative transfer" situation, which means that control manipulations appropriate for one type of machine are different from (or even the reverse of) the control movements required to produce the same effect on other machine types. This situation increases the accident potential to the operator, as well as to others in the vicinity. Accident potential is further increased by circumstances which do not allow for large error tolerance-specifically, emergency procedures. Reports of accident statistics cite operator inexperience as a primary cause of most accidents involving underground electric face equipment. Several factors contribute to operator inexperience, including: 1. High personnel turnover 2. Employee absenteeism 3. Current union practice of bidding for jobs.

Jan 1, 1974

The coal reserve base is defined for coalbeds having sufficient thickness for underground mining within a depth range compatible with economic recovery. The reserve data are compiled by the Federal Bureau of Mines by updating and reevaluating previous estimates of the U.S. Geological Survey, State geological surveys, and others. Through the application of computer techniques, the tonnages are compiled by State, county, coalbed, and rank. Coal reserve base is allotted to sulfur categories by a statistical apportionment of data from available Bureau of Mines reports and records. The coal reserve base in those States east of the Mississippi River, minable by underground methods, is estimated to be 169 billion tons in coalbeds greater than 28 inches in thickness to a maximum depth of 1,000 feet. Excluding those coals in reliability categories other than measured and indicated, the underground reserve base includes 162 billion tons of bituminous coal and 7 billion tons of anthracite. Of the total, 27 billion tons contains 1.0 percent or less sulfur. Most of this low-sulfur coal is in the southern Appalachian area. Approximately 16 percent of the underground reserve base is without available analyses. Included in this report is a glossary of terms applicable to a classification system for coal resources and reserves. The purpose of this system is to provide a common yardstick for determining coal resources and reserves.

Jan 1, 1974

By Robertson K. S, Hunter T. C

AEG-Elotherm's electromagnetic dosing channel, or Eldomet, is a recent invention enabling the transport and metering of molten metals. The development of a reliable refract- ory lining, and the use of suitable construct- ion and operating techniques has led to the successful application of the Eldomet for casting copper anodes at Copper Refineries Pty. Ltd.

Jan 1, 1974

By Whiteman P. C, Stacey G. S, Hunter G. D

Processing of lead-zinc and copper ores by Mount Isa Mines Limited produces large quantit- ies of concentrator tailings waste which is pumped as a slurry to special dams where the solids are allowed to settle and dry out. These areas are unattractive and show no signs of encroachment by plant life even though the surfaces of some dams have remained undisturbed for more than a decade. During 1970 Mount Isa Mines Limited commenced a long term research program in conjunction with the Department of Agriculture, University of Queensland to deter- mine possible methods of establishing a plant cover on this material. Research has defined the major factors limiting plant growth in the tailings medium. Modification of the edaphic conditions through fertilizer inputs, particularly of phosphorus and nitrogen, and alteration of "soil" physical properties by incorporation of mulching mater- ials, provided conditions which allowed plant growth. The outstanding "soil" amendment treatment was incorporation of fly ash, a waste product of the company's coal fired power stations. A range of crop and pasture species have been selected which have grown well with adequate irrigation under the amended conditions in the field. Further research is assessing a range of native plant species and agronomic techniques to provide a stable plant cover on the tailings dams.

Jan 1, 1974

By Casley G. E, Pritchard J

A single slurry fed fluosolids roaster was chosen to replace six multiple hearth roasters in the Copper Smelter at Mount Isa as part of the overall program to increase production from 100 000 to 155 000 tonnes blister copper per annum. The paper describes factors influencing the choice of the unit, problems encountered during the commissioning and details of the present roaster operation.

Jan 1, 1974

By C. B. Manula

Simulation continues to hold the spotlight among the Operations Research applications in the operational side of mining. One reason for this is the need to solve the many waiting line and storage problems common to the industry. A second reason for using simulation is the central requirement of retrospect testing. Acceptance of a model by management is more likely to depend on its tested performance rather than on the underlying validity aspects of the model itself. Mathematics have not been and may not be developed that will allow all desired system elements to be considered simultaneously. It is in this realm that simulation bridges the gap between theory and useful design procedures. One of the earliest published accounts of simulation at work in the coal industry is demonstrated by the application cf Monte Carlo methods to explore changes in future operating policies for an existing track system (Manula, 1963). By modifying certain control parameters, revision in design changes were evaluated in the computer rather than in the actual production section. A second application which has found wide use in practice is the VFI-OCR Face Simulator (Prelaz et al., 1968). The model developed here has the purpose of allowing the comparison of methods for room-and-pillar face operations end observing their effect on mining prior to actual installation. Proposed changes are tried in the model and the best of these are selected as a guide for better mire management: IBM's own simulation package, the System 360 General Purpose Simulator, has experienced heavy use in solving similar problems and other steady-state situations.

Jan 1, 1974

By David L. Brostrom, William C. Brice, Perry A. Canton

The business of mineral exploration and development has become much more than simply a problem of locating orebodies and designing mines. Favorable economic analysis of mining and processing feasibility is no longer sufficient to justify the development of a mine. New laws, enacted by virtually every level of government, require comprehensive land use planning, environmental analysis, mineland reclamation, mine safety studies, and many other considerations. This profusion of new laws says in effect, that the mining company is no longer responsible only to its stockholders. Mineral development today can be compared to a partnership. As in all partnerships, the risks and liabilities as well as the benefits are held jointly by all the participants. In addition to the mining operator, this partnership consists of the public, through its many levels of government, interest groups, and individual citizens. Therefore, you'd better know your partner very well - his responsibilities and capabilities. Mining is considered a high risk venture. The risk on the part of the operator and the lending institutions has long been recognized. The risk that the public and its government take in these mining ventures has now been recognized also. The people and their government have learned that they inherit, through abandonment or forfeiture, the mistakes and problems of individuals and companies regarding these natural resources. In looking through the "Mining Engineering Handbook" recently published by the Society of Mining Engineers, I noted that in their discussion of liability for excavations, the authors quoted from the book of Exodus, 20th chap., where Moses said to his people: "When a man leaves a pit open, or when a man digs a pit and does not cover it, and an ox or an ass falls into it, the owner of the pit shall make it good; he shall give money to its owner, and the dead beast

Jan 1, 1974

By Paul Torda

El presente texto analiza la posición de la institución educacional como "depósito" de talentos de ingeniería para futuras exploraciones dentro de posibles descubrimientos tecnológicos. En este sentido, la creación de un programa educacional adecuado genera el cultivo de una imagen del talento de ingeniería para los roles técnicos no tradicionales en la industria, como también para el gobierno local y el federal. El plan general involucra no solamente una ruptura con los procedimiientos tradicionales de clases, sino también origina nuevas demandas sobre los estudiantes por la independencia e iniciativa.

Nov 1, 1973

By Jorge Cáceres

El presente texto describe los diversos métodos para el tratamiento del agua de la Planta de Precipitación. Asimismo, se presenta el flow sheet, la maquinaria que se instaló en el área de San Felipe y se muestran los costos del tratamiento de dichas aguas al ser descargadas completamente limpias al Río San Felipe.

Nov 1, 1973