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By Walfrid Been

There are no particular nor unique features of iron mining that are not shared in some degree by all mining ventures everywhere. There are, however, at least three problems that have acquired a special emphasis from a unique cause. That cause is the embarrassment of riches under which the industry is suffering. The most obvious' feature of iron mining today is the copious abundance of usable ore and its almost universal distribution over the face of the earth. By the term "usable ore" is meant ore that is amenable to reduction by the usual and conventional processes. Amidst this plenty, three problems become acutely emphasized: 1. The geographic location that will provide a mine with the best market opportunity. 2. The size of the orebody that will be required to' return the preproduction investment. 3. The geometry and configuration of the orebody that will permit quality control measures to be effectively executed.

Jan 1, 1964

By Harry Teicher

The subject of Specialty Silica Products could encompass a broad range of materials, some of which would be familiar to members of the Society of Mining Engineers. With the concurrence of your chairman, I have chosen to limit my remarks to synthetic materials, not including such siliceous materials as diatomaceous earth, asbestos, quartz and clays. For purposes of discussion, I have classified Specialty Silica Products into two groups -- powders and liquids -- which I will discuss in that order and which are categorized in Figure 1. The synthetic silica powders are amorphous to x-rays and are manufactured by various processes resulting in products of a wide range of physical and chemical properties, as well as functional performance and applications. Applications or functional properties are generally dependent upon such physical properties as micron-sized particles exhibiting large surface areas per unit weight and low apparent bulk density. Their presence in various systems modify surface properties. As summarized in Figure 2, they act as viscosity modifiers, flow conditioning agents, anti-slip agents, anti-blocking agents, flatting agents in surface coatings, reinforcing agents in polymers such as silicone rubber and numerous other applications. Although the various types of silicas exhibit various levels of functional performance in these end uses, they are not usually equally effective as direct replacements and I will briefly discuss the various types of materials.

Jan 1, 1974

By Helmut Goehring

Surface mining has been used primarily where deposits of minerals were exposed or close to the surface. Surface mining can, therefore, be considered the oldest branch of mining. As the most accessible deposits became uneconomical because of the lack of suitable high capacity conveying systems, deep mining took its place. Only in the twentieth century was this trend reversed as high capacity production and conveying systems were developed. This rapid development was triggered by the steadily increasing demand for raw materials and fossil fuels, as well as by the ever increasing ratio between overburden and deposits.

Jan 1, 1982

By Merih Celasun

The literature in operations research centered on mineral exploration has been comparatively limited in view of the significant implications of mineral discoveries upon the national economies in general and mineral industries in particular. Much of what has been published is of somewhat unsure academic nature, indicating to a certain extent the scarcity of industrial applications. Mineral exploration activities present quite difficult operational and conceptual problems. The purpose of this paper is to discuss the principal characteristics of decision problems encountered in planning an exploration program, to indicate an optimization approach to a certain class of allocation problems, and to suggest directions for future research effort.

Jan 1, 1962

By Robert L. Wade

The two primary goals in underground coal mining are to improve safety and to lower mining costs per ton through increased productivity. However, as evidenced by the drastic decrease in. productivity since the enactment of the 1969 Coal Mine Health and Safety Act, (the Safety Act), these goals appear to be mutually exclusive. Millions of dollars have been spent in the res, arch and development of systems to solve this problem. Before the Safety Act, "productivity had experienced a 25-year history of continued increases ...? (Douglas, 1980). But since its enactment there have been dramatic decreases in productivity accompanied by phenomenal increases in mine costs. Labor trends, depletion of the more readily minable underground coal reserves and other factors have contributed to this situation, but the dominant factor is undoubtedly the Safety Act itself. To illustrate, prior to 1969 underground coal mine production was much greater than surface mine production but since then underground mine production has been declining at a rate greater than the overall growth rate of total coal production.

Jan 1, 1985

By Thomas D. Kaufmann

Introduction Mining has always been sensitive to the fluctuating income of downstream customer industries. The industry is now becoming more vulnerable to booms and busts as economic pulsations increase and demand for mining products shows little or no long-term growth. As the general economy has become more cyclical in the last decade, the capital-intensive primary industries have become more aware that timing as well as preparation of survival plans are vital in investment decisions. Strangely, however, some of us have not yet included the business cycle in our feasibility studies. Cyclic prices and volumes and fluctuations in profits and cash flows do not fit our linear models. The increased cyclical nature of our economy is recent and poorly understood. Forecasting peaks and troughs is still more an art than a science. Nevertheless, avoiding business cycle parameters can lead to error in value estimation and contingency planning of new projects. Metal and Mineral Industries More than half the iron and steel, aluminum, copper, lead, zinc, manganese, tin, nickel, molybdenum, cobalt, and chrome that we mine, smelt, upgrade, and recycle goes to construction, transportation, capital goods, and consumer durable industries. All are cyclical. Their products are consumed slowly, so replacement can be postponed in recessions. Purchases of such goods are usually financed by debt, and their customers are sensitive to highly cyclical changes in interest rates. During prosperous periods, people tend to buy capital goods despite high interest rates. Upstream industries also tend to be whipsawed by inventory cycles. With high interest rates and good transportation, downstream fabricators can lighten their inventories during recessions. They know that upstream suppliers can deliver supplies and raw materials immediately, And, with the advent of electronic accounting, the fabricator with timely inventory information can afford to hold fewer contingency stocks. Likewise, when recovery returns, inventories surge back through industry pipelines, accelerating demands on primary supplies. The price elasticity of most primary products is low. Their share of the value of finished products of the industries they supply is generally small. The 60 kg (130 lb) of aluminum in a car is vital. But whether it costs $80 or $130 will not visibly influence the demand for an automobile. With low elasticities of demand, the primary producer is hit with decreases (or increases) in prices and in sales volume, during recessions as well as recoveries.

Jan 6, 1984

By L. Arbore

Introduction Mine operators are interested in energy conversation in two ways. With our finite sources of energy, we are concerned for future generations. In addition, as mine operators, we want to minimize energy costs. Moving material represents a substantial amount of the energy used in mining operations. Wheeled vehicles are used extensively to move materials. And they derive all their energy from fuel. Energy is also required to overcome the vehicle's inertia, and internal and external frictional forces. Included in the vehicle's frictional forces is its suspension. Tires are an important part of this suspension. What influence do tires have on the overall fuel consumption of the vehicle? Does tire construction affect this influence? As far back as 1896, it was apparent that tires were a factor in fuel consumption. A test was devised in France using a coal-fueled steam-driven auto. The test measured whether there was any fuel savings with the new pneumatic tires rather than of the then commonly used solid tires. The result was a 28% savings in water and a 29% savings in coal on pneumatic tires. Today, the pneumatic tire is accepted, but there are differences in present constructions. Tire Construction: Bias vs Radial There are basically two types of tire construction, bias and radial. Bias tires have been around for about 60 years. Radial tires are more recent. They were developed to improve a tire's ability to withstand higher speeds and loads, as well as to improve tire life and vehicle handling. Another advantage of the radial tire is its lower rolling resistance. This characteristic results in lower fuel use by a vehicle. This has been demonstrated with passenger cars and over-the-road trucks. It is now being demonstrated with earthmoving equipment. A basic description of both types of tire construction should now be reviewed: The casing of a bias-ply tire is made up of crisscrossed textile plies or layers. The cords of these plies run on a bias, from bead to bead. The cords of each ply run on an angle relative to the cords of the adjacent plies. As the tire rolls and deflects, the angle between the cords changes, like the blades on scissors (Fig. 1). The cords of one ply pull one way, and the adjacent ply pulls another, straining each other. This movement generates heat. Since the same layers of cords wrap around under the tread, they

Jan 9, 1984

By H. Knorre, A. Griffiths, J. Loroesch

Introduction Hydrogen peroxide is known to the mining industry as a powerful oxidant. able to attack and to destroy cyanide, the most important leaching reagent (Knorre and Griffiths, 1984; Griffiths, 1988; Griffiths, 1988). [ ] The most recent development, however, is the use of H2O2 as an oxidant in the cyanidation of precious metals. This application may appear to be a contradiction to the above mentioned detoxification process. This can, indeed, be the case if certain conditions are not considered carefully. Degussa has developed a new process to enable the application of H2O, in this field without having any detrimental effect on the cyanide. The incentive to seek an oxygen supplier like H2O2 instead of air was the fact that one of the most important conditions for the fast dissolution of gold is the presence of physically dissolved oxygen in the pulp (Kydryk and Kellog, 1954; Warstell, 1987). [ ] Complete gold recovery within a reasonable leaching time may only be achieved if the pulp is saturated with dissolved oxygen. Gold losses in leach operations mainly occur due to the following reasons: In some cases, the saturation of oxygen in the pulp cannot be achieved by aeration due to the difficulty to transfer oxygen from the gaseous into the liquid phase. This happens, for example, in pulps with a high viscosity. In such cases, even violent aeration only results in a low concentration of dissolved oxygen in the pulp. In any case, the starting phase of leaching requires the highest amount of oxygen. Therefore, it is especially important to raise the dissolved oxygen level to saturation in the starting phase. Peroxide assisted leach process (PAL) The intention of the process is to introduce oxygen in a liquid form. As a result of intensive research work, it could be shown that hydrogen peroxide can be used as a source of oxygen in the leaching of gold ores. To avoid side reactions, the following conditions must be applied: Hydrogen peroxide must be diluted before it is added to the pulp. The dosage of H2O, must be properly regulated based on the oxygen level of the pulp. An important part of the continuous O, control is a special oxygen electrode, which resists the extremely abrasive action of the pulp.

Jan 1, 1990

By H. Knorre, A. Griffiths, J. Loroesch

Introduction Hydrogen peroxide is known to the mining industry as a powerful oxidant, able to attack and to destroy cyanide, the most important leaching reagent (Knorre and Griffiths, 1984; Griffiths, 1988; Griffiths, 1988). CN- + H202 => OCN- + H2O The most recent development, however, is the use of H202 as an oxidant in the cyanidation of precious metals. This application may appear to be a contradiction to the above mentioned detoxification process. This can, indeed, be the case if certain conditions are not considered carefully. Degussa has developed a new process to enable the application of H2O2, in this field without having any detrimental effect on the cyanide. The incentive to seek an oxygen supplier like H2O2 instead of air was the fact that one of the most important conditions for the fast dissolution of gold is the presence of physically dissolved oxygen in the pulp (Kydryk and Kellog, 1954; Warstell, 1987). 2 Au + 4CN- + 1 /2 O2 + H2O => 2 [Au(CN)2]- + 2 OH Complete gold recovery within a reasonable leaching time may only be achieved if the pulp is saturated with dissolved oxygen. Gold losses in leach operations mainly occur due to the following reasons: • In some cases, the saturation of oxygen in the pulp cannot be achieved by aeration due to the difficulty to transfer oxygen from the gaseous into the liquid phase. This happens, for example, in pulps with a high viscosity. In such cases, even violent aeration only results in a low concentration of dissolved oxygen in the pulp. • In any case, the starting phase of leaching requires the highest amount of oxygen. Therefore, it is especially important to raise the dissolved oxygen level to saturation in the starting phase. Peroxide assisted leach process (PAL) The intention of the process is to introduce oxygen in a liquid form. As a result of intensive research work, it could be shown that hydrogen peroxide can be used as a source of oxygen in the leaching of gold ores. To avoid side reactions, the following conditions must be applied: • Hydrogen peroxide must be diluted before it is added to the pulp. • The dosage of H2O2, must be properly regulated based on the oxygen level of the pulp. • An important part of the continuous 02-control is a special oxygen electrode, which resists the extremely abrasive action of the pulp.

Jan 1, 1989

By M. Dean Kleinkopf, John Callahan, William M. Shepard, R. N. Schnepfe

Despite lower prices and the uncertain future of nuclear power, uranium continued to be the big attraction in 1979 exploration activity. Uranium again dominated exploration programs across the US-not only in primary producing states such as New Mexico and Wyoming, but in potential producing areas from the northern counties of Minnesota to the Grandfather Mountain region of North Carolina. The moratorium on uranium leasing was lifted in Colorado and Montana, and exploration activity intensified accordingly. In Wyoming, what may be the biggest uranium deposit in the state was discovered by Anaconda Copper Co. near Jeffrey City, but in general, there were few major discoveries and activity was concentrated on existing exploration programs. The Department of Energy expects 1979 uranium exploration expenditures to total $339 million, compared to the $314 million spent by industry in 1978. Surface exploration and development drilling in 1979 is estimated at 16.1 Mm, up slightly from 1978 figures. Gold demanded its share of the spotlight in 1979. Soaring prices lured prospectors, investors, operators, and speculators to Alaska, California, Colorado, and Washington in a small-scale gold fever. Exploration for molybdenum remained strong in Alaska, Colorado, and Washington, where mineralization at the Mt. Tolman prospect is now estimated at 816 Mt averaging 0.09% copper and 0.10% molybdenum disulfide. Again this year, one of the major deterrents to exploration was the drive to set aside huge areas of land as wilderness preserves. In Alaska, where Interior Secretary Cecil Andrus has withdrawn millions of acres under the Antiquities Act, BP Alaska decided to close its Anchorage office, reportedly due to the lack of public lands available for mineral exploration. In both geophysical and geochemical activity, the year is best characterized as one of consolidation and development of previous advances in the state of the art, without any fundamental breakthroughs. Many companies were active in the development of instrumentation. Continuing interest in spectral IP resulted in the introduction of two instruments, one by Phoenix Geophysics, the other to be announced shortly by Geotronics Corp. Radiometric and borehole logging equipment received considerable emphasis, reflecting the continued interest in uranium exploration. MINING ENGINEERING'S review of 1979 exploration activity, including state-by-state highlights and a review of geophysical and geochemical activity, begins on the following page.

Jan 5, 1980

By Rush H. Spedden

Antoine M. Gaudin was a vigorously creative man and throughout his career an internationally respected leader of his chosen profession of mineral engineering. To his professional colleagues and clients and to his former students he was both "Professor Gaudin," their wise, inspiring, and enthusiastic teacher, and "Tony," their warm and beloved personal friend. Thus, his teachings and his unique inquisitive-creative approach to problems live on and grow in the accomplishments of his students. Antoine Gaudin was born at the turn of the century in Smyrna, Turkey, where his father was general manager of a French-owned railroad. It was there that he spent his earliest years, literally in the shadow of classic marbles from diggings at the site of Aphrodesias, which his father had rediscovered. From this, Tony developed an appreciation of the arts. He eventually surrounded himself with art treasures; he reveled in the beauties of nature, and he cherished his choice collection of rhododendron and azaleas. His artistic traits led him to take up painting when his daughter, Elinor, sought his help in blending her tints for a water color. In typical fashion he was not satisfied until he had become adept with pastels in capturing the muted tones of distant landscapes and the technical properties of light and color. Unfortunately not many paintings were produced. His paternal grandfather was Marc-Antoine Gaudin, for many years secretary of the Academie des Sciences in Paris, and a well known chemist and mineralogist whose primary interests included the synthesis of precious stones. In an autobiographical sketch written in 1939, Dr. Gaudin recalled: "As a child I saw many of the original synthetic sapphires and rubies which my father had inherited. This, coupled with my father's avocation of mining ventures and archaeology, early decided that I would become connected with the mineral industry." One can speculate that the archeological activities of his father, the mineral systhesis experiments of his grandfather, and his own early studies of mineralogy and geology formed a base from which his special talents as an experimentalist were to develop. Laboratory research under Professor Gaudin's personal guidance was often an intensive, fast- moving, and exciting experience--especially to a new graduate student. First of all, Professor Gaudin was a highly skilled observer with seem-

Jan 1, 1976

By William C. Baldwin

Unitization and containerization continue to grow with great rapidity throughout the world today. Every industrial nation outside of the Iron Curtain is devoting more and more time toward research of these developing sciences. Unitization and containerization are proving to be the solution to many of modern industry's most pressing handling and shipping problems. Manufacturers make large savings, carriers receive many benefits, and customers take an increasing interest in demanding that their shipments either be unitized or containerized. Unit-loads consist of items, packages or bulk materials pre-assembled into a convenient mass for handling by mechanized equipment and to fit the internal dimensions of carriers. It has been found that unitized handling and shipping offers cost savings too great to be ignored by anyone interested in the distribution of goods. At present, the benefits from unitized shipping and handling are being enjoyed only to a small extent due to the failure of many persons concerned with handling practices in recognizing only some of the advantages of unitization. Before the full benefits of unitized handling and shipping can be realized, some major changes in packaging and distribution practices will be necessary on the part of industry. Numerous investigations in the last two years show conclusively that there are more advantages and more inherent savings for shipping goods on pallets in unit loads than by any other method. There is no question that unit-load handling can offer significant advantages to the user over piece-by-piece package handling. Reduction in handling costs is the primary objective of such activities, but it is by far not the sole objective. Some of the other benefits that can be realized are:

Jan 1, 1973

By J. K. Conibear

Since the 1948 introduction of hydraulic fill at the Sudbury Ontario Mines of the International Nickel Company of Canada, 32,000,000 tons of water-borne sandfill and 420,000 tons of portland cement addition have been placed in underground workings. Fill method mining, currently conducted at six of the ten operating mines, accounts for 28 percent of the total mines underground production. Both classified mill tailings and screened alluvial pit sand are used as fill for cut-and-fill primary mining, undercut-and-fill pillar recovery, and backfilling of blasthole and shrinkage stopes. Cemented fill, consisting of a lean mixture of portland cement, is used in areas where a stabilized fill is required to reduce dilution and aid in the recovery of adjacent pillar ore.

Jan 1, 1970

By Robert R. French

Beneficiation of-low-grade nonmetalliferous mineral deposits by electronic color sorting is currently undergoing a period of rapid development. For those deposits in which the specific gravity, strength, soundness, electric and magnetic properties of the ore and gangue are similar the possibility of separation by color, reflectivity, or fluorescence offers hope for utilization of much poorer quality ore than previously thought possible. For those ores in which consistency of color is required or for which a dry process is preferred, the electronic color sorter is particularly adaptable. Electronic color sorters were first designed to process agricultural products and were small low-capacity units. However, the recent introduction of larger machines designed to process 6-in, diameter ore at a rate of 30 to 50 tph (Anonymous, 1966a), has brought color sorting into the capacity range required by many mineral producers.

Jan 1, 1967

By T. Yukimasa

Hachinohe smelter, a zinc-lead blast furnace complex with the annual capacity of zinc plus lead of 100,000 tons, had originally treated normal zinc and lead sulfide concentrates. However, it is currently handling a great variety of raw feeds ranging from complex sulfides to oxidic recycled materials in view of resource economy, most of which are unsuitable for zinc electrolysis. This paper reports on some significant efforts recently carried out on improving sintering operation, i.e., the increasing use of secondaries against harmful ingredients like halogens, and the substantial reduction in energy use as the results of various modifications and improvements.

Jan 1, 1982

By William G. Fischer

Basic laboratory tests initiated the. Rock Mechanics program. The stress-strain curve, modulus of elasticity, Poisson's ratio, the uniaxial rock strengths, Mohr's envelope, the stress at failure, and creep were investigated. A series of underground problems were then approached using this information; and various field measuring devices, most of which were developed by the Bureau of Mines. Initially, stress concentrations near mine openings were evaluated using the stress relief technique. This required an accurate determination of the pre-mining stress field. Later, stress concentrations associated with the cave line .sere studied. After about thirty stress reliefs over an appropriate time interval the effects of one type of mining could be compared against another. The microseismic technique was used to investigate a possible application of warning devices near the cave line. A study of mane reorientation was made Problems related to the shape and size of pillars and barriers were studied. Partial extraction mining systems were evaluated. The effectiveness of roof bolting patterns were examined. Control of roof stresses was attempted. A new system of mining in heavy ground has been developed using the information secured in the Rock Mechanics program without this system, mining in more than one instance would Nave been next to impossible. Indeed; from this one discovery alone, the Rock Mechanics program has paid off in improved safety as well as in dollars.

Jan 1, 1964

By Richard L. Ash

Less than optimum production in mining always results when poorly blasted material is provided at loading points. More often than not the cause is due to blasting founds that fail to fully control and utilize explosive energy. In many cases the problem exists because too few blasters understand how blastholes actually break rock and recognize that blasting is a three-dimensional process in designing their blasts. To better understand how blasts can be more effectively designed the two major rock breakage processes are described. In addition, the respective contributions of the borehole and detonation pressures are defined as are the specific roles of the several important blasting design variables. The concept of stiffness as an engineering principle and its significance in blasting design is introduced for explaining the breakup of rock. Basic guidelines for affecting control over fragmentation and side effects like over-break are offered.

Jan 1, 1975

By William K. Burriss

Computer technology was applied to solve three problems in the selling of certain industrial minerals to the glass and foundry industries. The computer solutions provide for better service to customers and have helped increase sales. II. Summary Electronic data processing techniques were applied: 1. To automatically and continuously "trace" rail car shipments of bentonite. 2. To aid our sales people in recommending to glass plant purchasing agents which of several possible feldspathic materials is the best value at any of about 100 glass plants and to give guidance on the amount of value difference. 3. To help in locating plant sites for three blending or pre-mixing stations to serve the foundry industry at minimum cost and with maximum tonnage and maximum profitability.

Jan 1, 1968

By Douglas D. Donald

The financial analyst's job is to make an objective appraisal of the investment opportunities which exist within the various industries under his supervision within the context of the economic model provided by his firm and the a climate of investor sentiments. Industry analysis is critical. When a major investment trend develops, usually the stock of all companies within the specific industry react in the same direction. I should emphasize here, however, that an investment trend is influenced by the economic outlook, but economics is not the only determinant - investor psychology and arbitrary political factors may be of equal or greater importance. Part of our job is to recognize trends early and determine whether they are valid. Following industry analysis, the analyst must examine the specific companies within that industry since some companies usually react more violently than others to industry trends, whether they be favorable or adverse. To simplify the process of evaluating an investment opportunity, it is convenient to isolate three types of factors which have a bearing on every sort of business although the degree of influence of each factor may vary from industry to industry. These categories are, 1) independent or external factors insofar as they are beyond the control of corporate management, 2) interdependent factors insofar as influence may be exerted by industry-wide action, and 3) dependent factors covering the area of internal decisions which are basically under the control of the individual corporate managers. Although the title of this paper, "The Corporate Use of Cash Flow," is only one segment of the third category, it may be useful to continent on the first two categories as well. The independent factors may be either economic or governmental. The economic factors include cyclicality which may be very high in the case of the basic commodity industries or relatively low as in the case of utilities. Underlying growth rates, another independent factor, may range from the business equipment industry with an annual growth rate of 14% through the electric utility industry with a growth rate of about 7% per year to the

Jan 1, 1970

By Harold F. Yde

Hydraulic tailings fill in the Butte deep level mines was based upon studies made in 1958 by the Anaconda Company Mining Research Department, which published Bulletin No. 35, entitled "Hydraulic Stope Filling". Since then, many things have changed. At the time of the Research Departments study, dry mine tailings were hauled by rail cars from the Anaconda tailings ponds, twenty-five miles distant, to the underground mines' tailings fill plants at the Leonard Anselmo, and Mt. Con Mines. Now, with the installation of the new Weed Concentrator in Butte, tailings is delivered by pipeline to a cyclone at the Kelley Shaft, and stope filling has become more highly automated and streamlined. Presently, mill tailings at approximately thirty percent solids by weight, is pumped from the concentrator, eight thousand feet horizontally and upward, to the Kelley Fill Plant, where they are dewatered and deslimed by three Krebs Model D20B Cyclones, which discharge the material into the cased and grouted mine delivery bore holes at desired densities up to seventy percent solids. The vertical boreholes and four-inch rubber lined Victaulic pipe carry the material downward to horizontal distribution lines, which in turn tap into the stops-filling, three inch, unlined steel Victaulic pipelines. The slurry may travel several thousand feet before it finally discharges into the stope, where it lends support to the mined-out area.

Jan 1, 1969