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By D. A. Karvonen

Although the economy in the Province of Saskatchewan has historically been agriculturally oriented, a major new source of wealth has been realized through natural resources such as petroleum and natural gas, coal and uranium and since the 1960's - potash. Potash or potassium chloride, in the form in which it is presently produced in Saskatchewan is used primarily as fertilizer, a source of potassium, one of three essential elements required for healthy plant growth with about 5 percent of production sold to the chemical industry for use in such products as soap and liquid detergent, glass and ceramics, textiles and some pharmaceuticals. Saskatchewan is estimated to have approximately 40 percent of known world potash reserves and its ten active mines account for some 25% of annual world production. The development of this resource was recognized to be important to the development of Saskathcewan. In an effort to guarantee a fair and lasting economic benefit to the Province of Saskatchewan the Potash Corporation of Saskatchewan (PCS) was created on February 4, 1975 through an Order-in-Council under the Crown Corporation's Act and later on April 1, 1976, the Potash Corporation Act provided for its continuation. PCS was given the mandate to acquire ownership of a significant portion of the potash mining capacity in Saskatchewan and to establish an organization capable of operating the facilities, marketing the product and conducting all of the other activities necessary for a successful corporation competing in the world potash industry.

Jan 1, 1983

By J. K. Lemley

The human element in large measure dictates success in contracting relationships. Because of our professional backgrounds, we view contracts primarily as either engineers, contractors or owners. A beneficial contractual environment--one in which decisions, risks and benefits are shared--demands equal consideration of all three points of view. Most of the older cities in the United States, for example, suffer from bad contracts--generalized, patched-together documents that represent an accumulation of modifications originally written to compensate for specific situations that have occurred over the years. Because such documents lack coherence, they often present conflicting instructions which lead to defensive, ultimately destructive attitudes among the parties involved in the day-to-day administration of the project. Good contract development begins with a strong central philosophy to which the details of the contract can be related. First, the owner should establish a comprehensive philosophy in which risks between the parties are identified. Following this, a specific contract document can be written to satisfy this established philosophy. The contrast between two opposed contractual situations, NYC Water Tunnel Number Three and the Seabrook Nuclear Power Plant Cooling Water Tunnels, illustrates how comprehensive, well-written contracts--contracts which share both risks and benefits--provide the basis for achieving quality construction that will reward engineer, contractor and owner.

Jan 1, 1983

By J. Frederick Stampfer

Current certification testing of self-contained breathing apparatus includes tests with human subjects wearing the apparatus while exercising. During these tests, certain apparatus variables are measured during rest periods. Because of concerns that the present tests may not accurately simulate the stresses to which an apparatus is subjected in the field, the Bureau of Mines proposed new human subject tests. It was also felt that different measurement techniques would supply more reliable data on the apparatus response to these stresses. The Los Alamos National Laboratory was asked by the Bureau to evaluate the proposed tests and monitoring techniques. The major conclusions derived during this study are these: (1) The proposed tests are not too physically demanding. (2) As long as human test subjects are used, a minimum subject weight should be required for certification tests. (3) Important apparatus variables are the breathing resistance, temperature, and carbon dioxide and oxygen concentrations of the inhaled gas. (4) Continuous monitoring should be used, rather than monitoring only during rest periods. (5) New pass/fail criteria based on realistic estimates of the user's physiological requirements, as tempered by present and future engineering limitations, are needed. (6) When available, breathing machines, rather than human subjects, should be used for most certification testing. (7) A more realistic ergonomics test than that proposed is needed. (8) A gas leak test for the system and a facepiece leakage test are also needed.

Jan 1, 1983

By James J. Anthony

High-angle in-pit conveying is an idea that is being seriously studied by a number of important mining companies in North America. Its application in coal, iron ore, and copper mining is expected to reduce mine operating costs considerably compared with the conventional discontinuous methods, such as truck haulage, which are fuel, labor, and maintenance intensive. Therefore, a mine introducing high-angle in-pit conveyors will gain a competitive advantage over mines which continue to use conventional haulage. While the capital outlay for in-pit conveyor systems obviously varies depending on pit depth, the angle of incline, and the capacity required, it generally will not exceed that of truck haulage when all Factors are taken into consideration. These factors include the cost of excavation, as measured in relation to the volume of minerals mined, the cost of building truck ramps and roads, and the capital outlay for the trucks and maintenance facilities. In many cases, in Fact, the capital outlay will be less than for truck haulage. This cost advantage will best be realized by new mines, whereas in existing producing mines the switch from truck haulage may involve the abandonment of a substantial capital asset.

Jan 1, 1983

By Allan M. Johnson

Case histories were used to document and evaluate deficiencies in underground mine closures which have resulted in post-operation problems such as subsidence shaft failures, acid or toxic water drainage and others. Three different underground mining districts in the United States were investigated; 1) an iron mining district in Michigan 2) coal mining districts in eastern Ohio and southern Illinois and 3) three metal mining districts in central Colorado. Previous work in the Michigan district on problems with subsidence and acid water drainage provided the background from which the concept for this project was developed Student investigators working towards their MS degrees in Mining Engineering did the work on the eastern coal and western metal districts. The combined studies show that problems from acid water drainage, subsidence and inadequately protected mine shafts are the most severe and widespread. Suggestions of a technical nature are presented as partial solutions to some of these problems. It was determined that pre-closure evaluations could result in the identification of some potential problems that may occur after the mine is closed. Early recognition of these problems would be an advantage for at this time more options are available to the mine operator to either prevent them or to plan for their occurrence. Mine closure and reclamation should be considered as a part of mining and be incorporated in the mining plan. This would result in reduced environmental impact and would be achieved at a lower overall cost to the mining companies and to society. The role of water in the occurrence of several types of subsidence during mine flooding was significant at some mines in the Michigan district. These mechanisms which involve, friction reduction, gravity loading, overburden transport and hydraulic forces in a flooded mine probably have a broader effect than is currently recognized. Control of these processes may offer some interesting options during mine closure. It is recognized that technical solutions alone cannot provide all of the answers to problems associated with underground mines. Education, modified attitudes on the part of regulators and operators, and a more realistic perception of the importance and value of mining by the general public are also needed.

Jan 1, 1983

By Robert C. Bates

Published information discussing uranium mine radon daughter controls and related costs was examined and used to develop an estimated (projected) cost per ton for any level of control. Results show a clear power function increase of cost for conventional dilution ventilation as the annual exposure limit is lowered. Projections can be made using any assumed changes in consumer price index (CPI) and radon daughter working level months exposure limit. Bounds on the estimated costs are provided, and applicability of the final equation is discussed.

Jan 1, 1983

By G. R. O?Neil

The justification for a "ligand- selective' approach to fine mineral beneficiation via flocculation is established initially. Special emphasis is placed upon the need to identify non-selective, interfering and complicating adsorption effects. Specific strategies directed towards the design and synthesis of complementary selective flocculants are detailed using a number of different polymers and chelating agents as examples. In this regard, the affinity of polymer-bound ligands for metallic cations, ligand concentration, possible modes of attachment, the application of spaced-out ligands and other considerations in the preparation of selective flocculants are highlighted.

Jan 1, 1983

By J. Roth

"While not taking issue with the general thesis expressed in Dr. Ridge's analysis of the role of genetic concepts versus observational data in ore exploration (Ridge, 1983), the criticism could be offered that the author tends to slight the importance of conceptual (i.e. theoretical) models in mineral exploration.As a general rule, observational data in science lacks significance and utility without a theoretical construct to organize those observations. Theory in turn dictates what observations are made-and which ones are judged important. Thus, for example, prior to the elaboration-and acceptance- of the current model for volcanogenic base metal deposits, the structural aspect s of these deposits were most closely observed and studied by explorationists. The nature of the enclosing rocks and any attendant alteration was given minimal attention, and certainly didn't figure prominently as an exploration guide.Similarly, the importance of alteration features to exploration for porphyry copper-molybdenum deposits was only perceived when a theoretical model was developed to account for these aspects. Indeed, many of these porphyry copper deposits were regarded as epigenetic vein deposits by geologists of an earlier era observing and examining on a different physical scale-and with a different theoretical bias.In constructing and evaluating such conceptual models, explorationists primarily rely on observation data and proximate associations; speculative thoughts as to ultimate provenance or crustal evolution clearly play a subordinate role, as Dr. Ridge argues. This, however, should not obscure the fact that concepts and theories do indeed exert a major influence in mineral exploration."

Jan 1, 1983

By Roland Froidevaux

The potential use of geostatistics for quantitative ore reserve reporting is shown using a simple gold case study as an example. The need of defining quantitative class limits is stressed, and a possible approach to this problem is suggested.

Jan 1, 1983

By Garth A. Maki, Douglas M. Smith

"The largest Canadian Lamella thickener installation to date, with 13,600 square feet of effective clarification area, is being successfully operated at the Rocanville Division of the Potash Corporation of Saskatchewan. This paper describes the operational principles and design features of the Lamella thickener, the testwork leading to its specification f or the Rocanville phase two expansion project and a review of the performance of the full- size unit which was ultimately installed.IntroductionThickening equipment operating in the Saskatchewan potash industry is generally situated within the main refinery building or a separate insulated an d he a ted structure due to the harsh winter climate and the need to closely control plant brine temperatures to en sure good flotation circuit performance Because these thickeners process large volumes of slurries, conventional basin-type designs tend to be large, ranging up to 46 metres in diameter or more. As part of the general effort to minimize capital costs, the potash industry has begun investigating the use of alternate high capacity, compact thickener designs. In this regard, PCS Rocanville undertook a program in 1978 to evaluate a LamellaTM thickener and one other type of ‘High Rate' thickener as alternatives to a conventional design for the phase two expansion project.This paper describes the operational principles and design features o f the Lamella thickener (manufactured by Axel Johnson lnc.), the testwork leading to the specification of a Lamella for the Rocanville expansion project and are view of the performance of the full size unit (1486 m2 of the effective settling area) which was ultimately installed and is now successfully operating in the Rocanville plant."

Jan 1, 1983

By Richard J. Gowen

THE FUTURE The environment in which we live appears to change so slowly that most of us are unaware that any change has occurred at all. As the years pass, we notice increasing smog in our cities, new variations in weather, the shifting landscape with changing populations, and subtle but ever present alterations in the quality of life. In considering the future of our environment, we find we must grapple with questions concerning the very future of life as we know it today. Questions of resources, technology, society, governance, and purpose. Let us focus on the future of our environment and, in particular, raise the question of who is responsible for the environment. We know that action, or lack of action, will clearly influence our future environment. It is fashionable to catalog the many short-sightedness of our forefathers in developing the technologies which support the style of living to which we have become accustomed. However, I shall struggle to resist the temptation to list the well known ills of our present environment. Rather, let us concentrate on the future in our consideration of the priority of the multitude of options proposed to relieve our current energy crisis. We have recently witnessed the dramatic effects of air pollution produced by Mount St. Helen's eruptions. In the state of South Dakota, we watched our blue skies turn hazy and felt our eyes sting with the presence of volcanic ash. We were appalled at the dramatic effects on the landscape, crops, transportation, and all aspects of life in communities immediately downwind of the volcanic eruption. But in a few weeks, life had returned to near normal on the earth's surface leaving the volcanic ash in the atmosphere to ultimately

Jan 1, 1983

By K. W. Morris

Of the fossil fuels used for power generation coal is by far the most variable and complex in its properties. A thorough review of the characteristics of the coal to be fired is essential before boiler design can begin. Major parameters such as heating value, moisture content and ash properties will determine not only the boiler size and configuration, but also the performance of the unit with respect to the thermal efficiency, particulate and gaseous emissions, and unit availability and reliability. An example of a review completed on a large low-rank coal deposit for a power plant will be described.

Jan 1, 1983

By J. Kinkead, R. M. Sherman, E. M. Frizzel

A recent research study performed under US Bureau of Mines Contract No. J0199088 "Modular Irrigation Equipment for Reclaimed Strip Mined Lands" investigated the feasibility of irrigation as a reclamation tool in the arid and semi-arid regions of the Western United States. Review of mined land characteristics, evaluation of irrigation systems, and assistance from the mining industry resulted in the design of two strategies for the implementation of reclamation irrigation using solid set systems. It is not the intent of this paper to suggest the generalizations made on the basis of a six state area can extend to the design of an irrigation system for a specific mine site. The purpose is to present two irrigation strategies that may be implemented with solid set irrigation in this six state area. The reader should note that the following is the result of research and, therefore, original concepts were presented. The ultimate validity of these concepts will be determined by future field tests.

Jan 1, 1983

By Robert C. Handfield

The trip from Denver southwest to Gunnison crosses seven main geologic and physiographic areas as shown on the accompanying map. These are: I Mesozoic and Tertiary sedimentary rocks of the Denver Metro area from downtown Denver to the foothills near Morrison. II Precambrian metamorphic and igneous rocks of the Front Range from near Morrison to the west side of Kenosha Pass. III Sedimentary and volcanic rocks of South Park (Paleozoic, Mesozoic and Tertiary) from the west side of Kenosha Pass to Trout Creek Pass. IV Precambrian granitic rocks (1,350-1,480 M.Y.) between Trout Creek Pass and the Arkansas River. V Tertiary and Quaternary sedimentary rocks and sediments of the Arkansas River valley. VI Precambrian metamorphic and igneous rocks and Paleozoic sedimentary rocks of the Sawatch uplift from Maysville to near Doyleville on the west side of Monarch Pass. VII Mostly sedimentary rocks of Cretaceous and Tertiary age from the Doyleville area west to beyond Gunnison. Each area will be elaborated in the following pages but no detailed road log is given since these are available elsewhere. An attempt has been made to point out some deposits and features of interest to economic geologists but it is by no means complete.

Jan 1, 1983

By S. J. Rodgers

This report presents guidelines on methods of dust control in conventional coal mining operations. The normal mining cycle and equipment used in a room and pillar conventional section are described. Main ventilation, section ventilation and face ventilation are discussed in detail. Proper installation of line brattice, maintenance of proper air flows at the face and split ventilation are stressed. The effects of maintaining the end of the line brattice near the face are described. The advantages and disadvantages of blowing and exhausting face ventilation are presented. The use of water sprays on cutter bars and loading machines is described. The design of a nonclogging water spray system developed under a Bureau of Mines contract is presented. Other methods of reducing dust exposure are discussed and include alternative procedures for shot firing and administrative controls.

Jan 1, 1983

By Floyd C. Bossard

In underground mining operations, the over- riding issue has to be protection of worker health and safety. The employees underground, making a living in a dangerous occupation, know these are major issues. These men bargain their lives and health on the presumption that the operating management knows its business, and they, the underground employees, can pursue their occupation with the assurance that management has provided a safe and healthy ambient underground environment. When management assumes the mantle of protection of underground workers, it has to be positive that qualified engineers have designed the project, and that capable operating personnel are in charge and always available. Those persons with these responsibilities must be knowledgeable in the engineering and occupational health aspects of sine ventilation. The ultimate function of a mine ventilation system is to provide a comfortable, healthy and safe ambient environment for the underground workers. The attainment of these objectives has been complicated with the increased application of electrical equipment and diesel-powered mechanized mining equipment underground (discharging toxic diesel emissions); increased production rates with the attendant increased production of airborne dust; and mine development in increasingly hostile mineral formations containing combustible strata gases, radon gas emissions, along with high heat and humidity. In general, the modern mechanization of present mining operations has resulted in a sore complex set of problems for the engineer planning the underground ambient environment.

Jan 1, 1983

By L. R. Verney

A number of interrelated factors influence the economics of the sulphide smelting of copper, lead, zinc and nickel. This paper discusses these factors, mainly from a US point of view, and shows how they affect the cost of construction and operation of new and existing plants. The paper shows how metallurgical plant construction costs and the consumer price index have increased at a much faster rate than metal prices thereby making some metal mining and production operations within the USA, Canada and the EEC less profitable than operations elsewhere. This in turn inhibits new "grass roots" metallurgical developments. It is explained how retrofit of existing pyrometallurgical plants can be a more viable development than the construction of "green field" plants, especially if such retrofit improves, energy efficiencies, overall operating costs and reduces emissions of sulphur and other toxic wastes. Some aspects of metallurgical plant operation are examined, especially for copper and nickel, to show how changes in operating practices may develop in order to improve overall smelting economies, especially when developed in conjunction with objective retrofit. The paper also examines some financial aspects, especially insofar as the disparity between terms for loans offered to third world countries and the USA and the EEC are concerned and also comments upon the need, especially within the USA, for legislation to permit rapid depreciation of capital. Specific comments are made about environmental aspects, including the lack of uniformity of pollution control legislation and how environmental considerations may have some bearing of the location of future smelting operations.

Jan 1, 1983

By Roy E. Peterson

The Bureau of Mines has been developing and evaluating methods for beneficiating the large deposits of nonmagnetic (oxidized) taconite located on the western Mesabi Range. In this segment of the research, a sample representing about 0.5 billion tons of nonmagnetic taconite from near Grand Rapids, Minn., was beneficiated using a reduction roasting, magnetic separation, flotation process. The sample contained 32.1 pct iron and 49.1 pct silica. Tests were conducted both on a bench scale and with a 1,000-lb/h pilot plant. In the bench-scale research a con-centrate containing 69.0 pct iron and 4.5 pct silica was produced with an iron recovery of 82.1 pct. In the pilot plant, reduction roasting was conducted in a 35-ft kiln using lignite as the reductant and major source of fuel. Dust from the kiln exhaust was pelletized and recycled to the kiln. The roasted taconite was beneficiated by magnetic sep-aration and flotation to produce a product containing 67.9 pct iron, 5.5 pct silica, and 69.7 pct of the iron in the kiln feed. The cyclone separation in the grinding circuit was sharpened by demagnetizing the cyclone feed in a 400-Hz, 1,000-Oe magnetic field.

Jan 1, 1983

By Mark E. Gershon

The development of long term plans and schedules for strip mines now faces many companies, especially those developing large properties in the West. The rule of mining the lowest strip ratios first, while delaying equipment acquisitions and recouping investment the fastest, creates the situation where stripping ratios are too high in the latter years of mining operations. A program concept taking life of mine return on investment into account is developed in this paper to optimize mine scheduling and equipment acquisition. In addition, quality considerations (heat content, ash, sulfur, washability) can be considered by including the appropriate blending constraints to meet contract requirements.

Jan 1, 1983

By R. J. McClincy

The potential techniques for the direct smelting of copper sulfide concentrates to blister copper were evaluated from the standpoint of commercial application. Many existing smelters are adaptable to direct smelting practice but only with improved control of metallurgical performance. Modified and innovative procedures for slag cleaning and metal refining, prerequisites to direct smelting, are presented and discussed. The ability to smelt directly to blister copper using existing equipment and eliminating the need to convert matte offers ,significant advantages to traditional smelting practice from the viewpoint of cost, 'S02 control, and process simplicity.

Jan 1, 1983