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By J. G. Pippenger

The Coteau Properties Company's Freedom Mine is a surface lignite mining operation located near Beulah, North Dakota. Coteau, a wholly owned subsidiary of The North American Coal Corporation, produces more than 13.5 million tonnes per year, ranking it among the largest mines in North America. In 1993, Coteau ranked seventh in terms of annual coal sales, becoming the largest mine outside the Powder River Basin of northeastern Wyoming. However, for the Freedom Mine to stand among these Powder River heavyweights, Coteau over-came several obstacles, including a coal seam with three quarters the heating value and overburden to coal ratios three times higher than the Powder River mines. Coteau's ability to compete has been built around a program of continuous productivity improvement, cost efficiency, and innovation. This report highlights a few of the major improvements implemented in recent years.

Jan 1, 1995

By John E. Miller

In recent years there has been increasing concern in the mining industry over the availability and high cost of diesel fuel to support mining operations. Unit Rig & Equipment Co. has been deeply involved with the development and testing of the newest designs for trolley assist. Beginning in dune 1980, Unit Rig modified and commissioned six 156 metric ton (170 short ton) trolley assist haulage trucks at two mine locations in South Africa. Operating haulage trucks with General Electric GTA 15E/776 drive systems were chosen for the tests since this size of truck represented the majority of the population of large size haulage trucks and the greatest technical development problems. Test operations have proven the feasibility of equipment designs in actual operation and preliminary economic data has convinced the operators to proceed with planning to modify their entire mining operation to use trolley assist. The initial capital investment incurred for trolley assist can be recovered in a short period of time. Following this quick capital recovery, mines will continue to realize lower operating costs through increased productivity and lower diesel consumption.

Jan 1, 1980

By E. B. Graves

I have been asked to talk to you this morning about phosphate marketing and distribution. In discussing this I will attempt to answer such questions as: What is phosphate? Where do we get it? What form is it and how do we sell it? How do we distribute it? How is it applied? And last, but not least, What about the future? To start with, phosphate is one of the three primary plant nutrients. It is the element essential for root structure of plants. Plants, like humans, need a balanced diet. Thus, the amount of phosphate required by individual plants is, in part, related to how much of the other nutrients are used. Virtually all soils contain a certain amount of available phosphates. Back at the turn of the century the most common source of additional plant nutrient, including phosphates, was from cattle manure. The use of chemical fertilizers is something that has grown significantly during the last half century, and in particular, the last 20 years.

Jan 1, 1977

By F. K. Spragins

The growing demand and a diminishing supply of conventional crude oil in North America are bringing about an ever increasing interest in the so-called "synthetic fuels". With one commercial plant already in full production, another in the planning and engineering stage, and still others being seriously considered, the Athabasca tar sands is proving to be a leading center of interest. Here, and in the closely related deposits, reserves in place total over 700 billion barrels.1 This major source of new oil is about ready to play a significant role in the filling of ever increasing market demand. When and if fully developed, the Athabasca tat sands could make both Canada and the United States substantially independent of all off-shore supplies of crude for many years to come. Its product, a high-quality, low-sulphur synthetic crude, is beginning to enter the market place at a most favourable time.

Jan 1, 1972

By H. Y. Sohn

The paper discusses two processes, flash ironmaking technology (FIT) and moving-bed ironmaking technology (MBIT), which aim to reduce energy consumption and greenhouse gas emissions in the ironmaking industry by using concentrate directly without pelletizing and without using coke.

Aug 1, 2023

By M. P. Meehan

The purpose of this paper is to present the Anamax Instrumentation Department's: responsibilities, organization, preventive maintenance, test facilities, training and applications. The Anamax Mining Company is a general partnership between AMAX Arizona, Inc. (a subsidiary of AMAX INC.) and The Anaconda Company (a subsidiary of Atlantic Richfield). Anamax's product and by-products include: copper, molybdenum, and silver; uranium is to be added as a by-product in early 1980.

Jan 1, 1980

By A. F. Peterson

There is no single mining problem at Benson that does not exist at some other mine. There are four, however, that require special attention primarily because they occur together and have an influence on each other. These are the nature of the mineral occurrence, the shape of the ore body, the operating schedule, and the climate. It is the purpose of this paper to describe mining practices in relation to these four factors. Iron ore was first noticed in the Star Lake area early in the nineteenth century. Prior to Jones and Laughlin leasing the facilities built by the Defence Plant Corporation, several companies tried to mine the ore body but gave it up as uneconomical. While there is a little high grade (40%) magnetite, most of the ore contains 20 to 25% iron and not enough was known prior to World War II to design a profitable operation. By 1943, and certainly in the years that followed, technological developments in ore dressing and mining not only put the magnetite into the category of a commercial ore, but made possible the concentration of the non-magnetic iron mineral, martite. This last development nearly doubled the ore reserve. Jones and Laughlin bought the DPC holdings in 1946 and has since expanded the plant to its present capacity of 4,400 gross tons of concentrates daily or 1,600,000 gross tons per year. Magnetite makes up 62% of this production at the present time, but it will be necessary before long to bring martite production up to about 45% of the total because of the ratio of the two ores in the reserves. To keep the plant supplied, 14,000 to 15,000 tons must be mined and crushed daily, with a ratio of concentration that varies from 2.8 to 3.4. The ore body is 12,000 feet long and varies in width from 600 to 1,500 feet. The waste rock is, for the most part, a granite gneiss, and the overburden, of which little is left, is a glacial drift sand. For the entire reserve, there is a half ton of rock for every ton of concentrate, but the stripping ratio is more than one to one at present because of the existence of more rock in the upper mining levels in relation to the ore. The dirt stripping or development work that cannot be handled by company facilities is contracted to an outside firm. The need for this diminishes every year and will soon disappear. The deposit looks like a "J" in plan, with the long leg running approximately north and south and the short leg to the west. The primary crushing plant, consisting of a 54" gyratory followed by two 18" gyratories and a 1,500 foot conveyor belt to the fine crushers, is located on the third level where the long and short leg of the mine meet. The widest part of the pit lies just the north of the crusher. The mine is operated on a lease that expires in 199l0 There are two fee owners, the Benson Iron Company, which owns slightly overhlf of the reserves, and the Newton Falls Paper Company, which owns the balance. There is no appreciable difference in the mining on the two fees, so the ore is removed in strict proportion to calculated reserves during each year. Basic mining equipment consists of eight 45 yard electric shovels, a fleet of twenty-five 22 ton end dump trucks, eleven churn drills for nine inch blast holes, and two small percussion drills for four to five inch holes, There are the normal auxiliary items, such as dozers, graders, wagon drills, and two drop-ball cranes. Power is purchased and, where practical, is used at 4100 volts. Pit drainage pumps can handle a maximum of 11,500 GPM from the several sumps, but water is a problem only during the spring or when a sudden thaw follows a heavy snowfall.

Jan 1, 1958

By Lewis J. Patterson

In the period of time allotted to this paper, an attempt will be made to cover a great deal of territory, figuratively speaking, as far as our experience with ammonium nitrate is concerned. In giving this subject the "broad-brush" treatment, it will be necessary to generalize on the major points which at the same time will permit me to avoid, to a great extent, any involvement in the purely technical and theoretical aspects of blasting. The practice of theorizing before a new idea is tried has practically been discontinued in our organization simply because experience has shown that, almost without exception, theories have fallen aside as some new development takes its place. In regard to blasting, logic and experience seem to have little place in this phase of quarry operations. As the use of low cost blasting agents was introduced in our operating practice, a man who had no previous experience in the field of blasting but with sound knowledge in safety procedures was given the responsibility of supervising the drilling and blasting operations. A total lack of experience is not ordinarily recommended as a prerequisite to assuming the responsibilities of a supervisory position. However, in this case it was obviously a wise decision because there were no pre-conceived ideas as to what techniques would or would not be successful.

Jan 1, 1958

By K. A. Brame, L. G. Austin, R. S. C. Rogers

The breakage parameters of phosphate ore were determined by batch first-ordering grinding studies in a laboratory ball mill according to the Austin, Klimpel, and Luckie procedures. The results were scaled to five larger mills of 0.56, 0.82, 8.36, 4.41, and 5 m in diameter assuming equilibrium ball charges for the full-scale mills. The results were used to predict product size distributions and capacities for batch grinding in the smaller mills and open-circuit grinding in the larger mills. The predicted capacities were in approximate agreement with experimental values except for the 5-m diam mill. The Bond method gave capacity predictions that were 4570 to 150% too high.

Jan 1, 1987

By Robert P. Moodry

It was attempted to revitalize an old sulfide leach dump by increasing the oxygen content within the dump. Compressed air was introduced into the old dump. This was accomplished by drilling 300 foot angle holes into the dump surface with an Aardvark drill which holes are then cased with 1-1/2 inch perforated PVC pipe. Compressed air is injected through these cased holes during a 10 day rest cycle. The second case consists of bedding perforated polyethylene pipe at the interface between the old dump surface and the next Lift of a new dump. Compressed air is then blown through the bedded perforated pipe on a continuous basis while leach solution is applied.

Jan 1, 1976

By Adam Bedell, Jack Raymer, Brad Crenshaw

Tunnel contracts often include provisions for pre-excavation probing and grouting for areas ahead of the tunnel heading. If grouting triggers are met, tunneling stops, and grouting is performed. There is substantial variation within the underground industry on what criteria are applied to the grout verification hole that is drilled post-grouting and before excavation resumes. The criteria for determination of the effectiveness should be dependent on the geology and local hydrogeologic conditions. The purpose of this paper is to present specific criteria that can be used by a practitioner to determine whether tunneling can resume or if additional grouting is required.

Dec 1, 2022

By G. E. Erdman

This paper presents talc milling guided by a theme of "So You Want to Be In The Talc Business". Such a theme strikes a cautionary note to warn the uninitiated of potential pitfalls, and this paper will cover briefly some of the technical traps as well as one of the larger talc milling operations. It is important to our purpose to pre- sent some of the market and mineral complications that make the business of producing and selling industrial talcs much more intricate than an outsider would perceive. Metal markets by comparison are great worldwide pools into which production streams of generally identical metals can flow over a weir of market prices. Industrial talc markets are not as well defined and often must be developed by the producer working closely with a specific customer or groups of customers to prove out the attributes of the specific product from a new property. All the negatives of a new market seem to work against the introductory talc in the forms of industry or customer reluctance to change, sales prices, cost of delivery, mode of transportation, health considerations of the minerals and many more. Just locating the potential customers for a new industrial talc may be a substantial undertaking. Thus, an analogy of the worldwide metal market might compare starting a new talc operation to trying to gather up enough fallen rain drops to be able to start a production stream of a worthwhile size.

Jan 1, 1984

By Y. David

In 1990, the United States became only the second country (after China) to produce more than 900 Mt (1 billion st) of coal in a single year. US production of bituminous and subbituminous coal, lignite and anthracite totaled 933.5 Mt (1.029 billion st) in 1990, 5% more than in 1989. The production gains were largely due to the rebuilding of depleted coal stockpiles by electric utilities and a surge in US coal exports. Domestic coal consumption essentially remained at its 1989 level. A slight increase in electric utility coal consumption was partly offset by a decline in metallurgical coal use. The use of coal in other industries and in the residential-commercial sector remained virtually flat.

Jan 1, 1991

By Joseph E. Worthington

Increases in the price of gold starting about five years ago, and rapid fluctuations since then, have caused a substantial popular interest in the noble metal. Gold prospecting had been at low ebb since the end of World War II in most of the United states except for a flurry of activity in Nevada occasioned by the Carlin and Cortez discoveries. The last five years, however, have seen a great awakening of interest in gold exploration as well as an opportunity for education for many explorationists in the geology and other vagueries of gold deposits. The present writers have participated over the last few years in a search for gold deposits throughout the United States. This search was greatly influenced by the geologic studies of Dr. Wm. Spence at the Haile Gold Mine in South Carolina as reported in a companion paper. Spence's studies resulted in definition of a geologic model that has proven useful in a number of other geologic environments in the united states. These programs were all carried out under the auspices of Cyprus Mines Corporation and permission by Cyprus to present these results is gratefully acknowledged. The writers, however, reserve for themselves all responsibility for the results and conclusions. The exploration program to be described began in the southeastern United States. Spence's studies provided a reasonable basis for interpreting and understanding the geology of the Haile deposit and also provided a means for predicting additional occurrences. This concept was then expanded to other gold occurrences in the Piedmont and became an effective tool for evaluating other prospects. Finally it became evident that the concept could be applied in some western gold districts. The following discussion will then include descriptions of other Piedmont examples and a few western districts that also appear to fit the pattern.

Jan 1, 1978

By J. E. Bevan

Once mining compromises the stability of a rock mass, the dangerous task of roof bolting begins. Many attempts have been made to automate this process, but there are still many refinements that need to be made. In the past, roof bolting modules were designed around the abilities of a human operator. Currently, researchers are taking a new approach that focuses on designing modules that can utilize bolting methods that are easily automated. A non-rotating anchor that is locked into position by a linear force (as opposed to a rotational force) was designed by researchers at the U.S. Bureau of Mines. Once the bolt is secured in the bolt-hole by the anchor, the bolt is tensioned and a collet is used to secure the other end of the bolt. This process replaces the traditional bolt-nut fastening method. This program is part of an effort at the U.S. Bureau of Mines to automate the coal mining process.

Jan 1, 1994

By M. M. Hajdasinki

A project's rates of return (RORs)1, be it the internal rates return (IRRs) or one of the many IRR surrogates, frequently needs to be approximated. The success and efficiency an ROR- approximation procedure depend on the quality the approximation-initiating parameters, such as bounds or seed values (guesses). The existing approximation procedures commonly use bounds and guesses suggested by intuition rather than supported by mathematical considerations. This paper presents three mathematically founded ROR-bounding and eleven ROR-guessing approaches and examines their suitability by using examples of typical project cash-flowpatterns (CFPs). The calculated bounds and guesses not only improve the approximation efficiency, but also allow the process of the ROR discovery to be automated, thereby making it more convenient and reliable.

Jan 1, 1999

By Patrick Doig, Ross Webb

The Bradshaw Section 5A Interceptor involves the construction of two miles of 108-inch, finished diameter tunnel in dry soils. Excavation is generally by Lovat TBM with ribs and lagging support. The tunnel is beneath a recreational parkway and stringent measures have been enacted to preserve the parkway and minimize disruption to the neighborhood. Apart from these constraints, the project would have been unremarkable but for the intervention of CalOSHA and the local fire department who ordered extraordinary fire protection measures. The paper discusses the cause and effect of these measures and comments on the potential repercussions for other projects.

Jan 1, 1999

By J. J. Scott

Friction Rock Stabilizers, trade name Split Set*, is a new support system invented by the author and under development by Ingersoll-Rand and Lee-Norse Company. Split Sets are a substitute for standard bolts or fully grouted resin bolts and have certain advantages which are: 1. Improved safety for the miner 2. A rational design is possible based on rock mechanics principles 3. Supports can be made either to be yieldable or rigid 4. Supports can be used to build a roof beam or to suspend roof material 5. It is cheaper than the resin system and costs about the same as standard bolts.

Jan 1, 1974

By J. Bartrum, A. Bowler, G. Butcher

The purpose of this paper is to outline the design, specification, and operation of the 8.5-m- diam (28-ft-diam) SAG mill commissioned at Kidston Gold Mines during January 1985. Amenability of Kidston ore to SAG milling, coupled with substantial cost advantages, led to the specification of this mill, equipped with variable speed drive to overcome the large variation in ore hardness. Operation of the mill is effected via a number of automatic control loops. Problems experienced with automatic control plus other electrical and mechanical failures have led to design changes and the formulation of future operating strategies.

Jan 1, 1987

By I. S. Parrish, D. W. Kappes, G. G. Austin

Micron-sized gold disseminated in lower Cambrian siltstone has been found at the Sterling mine near Beatty, NV. A shoestring-shaped body has been developed by central and fringe drifts and is being mined via a modified retreat room and pillar system. The siliceous ore crushed to 5.08 cm (2 in ) is stacked to 4.6 m (15 ft) over a layered sand, gravel, and impervious PVC base. Gold is leached using a 0.1% cyanide solution and deposited on activated coconut shell carbon. Stripping of the carbon by hot solutions of 1% NaOH and 20% Ethanol yields overall recovery of about 75% of the fire assay head.

Jan 1, 1983