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By P. Hadzeriga

Ion exchange techniques have been growing fast and spectacularly in all phases of Science for the last two decades, but still its acceptance as a unit operation in Metallurgy is resisted. Mainly this is because ion exchange procedures are thought of as glamorous techniques by which only relatively expensive metals are to be recovered. Perhaps this concept comes from the early and basic marriage of uranium and other high price metals and ion exchange procedures. The general trend is that ion exchange technique requires equipment and materials which are too expensive to economically perform a chemical step whenever "cheap" commodities are produced. However, we are here presenting a means of utilization of waste hydrochloric acid by an ion exchange technique. We have studied this from the engineering and economic standpoint in a number of variations of the main procedure discussed here and we-conclude that under proper economic circumstances, the cost of the ion exchange material as well as the equipment and labor involved in the ion exchange section, is by no means unreasonable.

Jan 1, 1964

By D. D. Harbuck

Previous studies at the U.S. Bureau of Hines have shown that only 70 to 80% of the germanium in domestic zinc process residues can be extracted during H2S04 leaching. To increase germanium extraction, the Bureau developed and researched the hypothesis that minor amounts of germanium and zinc silicate, both present in zinc calcine, dissolve during the leaching stages of zinc processing, forming soluble germanium and silica gel. This silica gel then selectively adsorbs germanium from solution, rendering the germanium insoluble. Testing showed that as the amount of silica gel formed increased, the amount of insoluble germanium in the zinc residue increased. Several processing alternatives are presented for overcoming this problem.

Jan 1, 1991

By R. L. Miller

The potential for recovery of enriched uranium from spent nuclear fuel which has been consolidated into a nuclear waste form was explored in the studies reported here. The waste form of interest is iron-enriched basalt (IEB)--a silicate-based, fused-cast ceramic. IEB samples were prepared containing fuel assembly materials that simulate the core debris of Three Mile Island Unit II;1,2 the nominal composition of the consolidated waste form is given in Table 1. Ore Types The IEB samples, or man-made uranium ores (MMUO), are in two different mineralogical forms. Each MU0 was made by melting the constituent materials and holding at about 1500°C for 1 h. The MMUOs were then heat treated to control crystallization and crystal growth and then cooled to room temperature.

Jan 1, 1983

By Y. A. Attia

Auriferous sulfide ores often contain very finely disseminated gold and other precious metal particles inside the sulfide crystals. The encapsulation of precious metal particles gives rise to the refractory nature of such ores to current extraction methods. As a result, these fractions are frequently lost in the tailings. The purpose of this work was to investigate the feasibility of pretreating these refractory tailings with bioleaching before employing standard extraction techniques such as cyanidation. Leadville gold ore tailings containing auriferous pyrite were first concentrated by froth flotation. The pyrite concentrate was treated for different periods of time with 12 weeks adapted thiobacillus ferrooxidans before cyanide leaching. The bioleaching of the concentrate before cyanide leaching increased the gold extraction from 32% to 95% and that of silver from 48% to more than 98%.

Jan 1, 1987

By Neal P. Cochran

The Office of Coal Research Program has been outlined in our Annual Report for a number of years and reported on by various members of the OCR staff as well as by our contractors. The program is national in scope and is intended to develop new and improved uses for our Nation's coal resources and to maintain coal in a favorable economic position, vis-a-vis, the other energy forms. A program has been developed that includes conversion of coal to gas, gasoline and other petroleum-type products, and to electricity. These projects are only one facet of the OCR program albeit an important one. In many of the conversion projects we have underway, original development work has been done with bituminous and sub-bituminous coal. It is the intention of this paper to present a general outline as to how lignite might fit into one or more of these projects as a raw material. Our national lignite reserves are vast in scope and this has been recognized in the OCR program by development of a project specifically for lignite and by including lignite as a test raw material in many other projects. Project Lignite is intended to develop the Cop Acceptor Process for conversion of lignite to a high B.t.u. gas. In this effort we have included the design, construction, and operation of a lignite gasification plant at Rapid City, South Dakota. The work is being conducted by the Consolidation Coal Company and is an outgrowth of their laboratory development of this process. The first portion of our effort included a detailed economic study of a somewhat arbitrary grouping of States designated Market Area A that could be expected to use gas manufactured in a lignite gasification plant. The area included the Dakotas, Minnesota, Nebraska, and Iowa. This geographical area could readily be served if a process could be developed for converting North Dakota's lignite reserves, estimated at 351 billion tons, to high B.t.u. gas. Our study showed that Market Area A had a potential commercial- industrial market of one trillion cubic feet of gas a year. To meet this demand, we believe that part of the load can be obtained from commercial lignite-to-gas plants. At the time of our original study, we concluded that gas could be delivered to the city gate in Market Area A at about 45¢. As a result of price escalation in the interim, our estimate today might be slightly higher, but not significantly so, since some parts of the process appear better today than they did at the time of the original projection.

Jan 1, 1968

By Devraj Sharma

This paper presents technical issues in the design and management of a retorted oil shale disposal site. Major physical and geochemical mechanisms which affect the disposal are: heat transport, moisture migration, chemical species transport, auto-ignition, and mechanical behavior alterations of the retorted oil shale pile. The interaction of these mechanisms and their relative magnitude will affect the environmental behavior of the pile. The paper discusses the coupling between the mechanisms, presents a framework to quantify the processes by laboratory and field measurements, and in addition discusses the use of mathematical models to provide quantitative predictions.

Jan 1, 1981

By O. R. Swendseid

The Mountain Con mine is a relatively old, deep mine located in Butte, Montana. Operations at this property through the present shaft were started before the turn of the century. As mining progressed to depth, increasing demand for ventilation facilities and changing mining conditions made it convenient to convert some nearby shafts to airways. The fact that these openings had not been originally planned for use as airways made it necessary in some instances to utilize long and inefficient already-estab¬lished entries to service working areas. This situation existed in the Lexington fresh air system. The Lexington system consists of a vertical, 3-compartment shaft extending from surface to the 3200 level and a series of 2-compartment air raises and old horizontal-haulage openings extending into a mining area several thousand feet west of the Lexington shaft between the 3900 level and the 4200 level. Because of restrictions and high resistance in the portion of the system between the bottom of the Lexington shaft on the 3200 and the mining area on the 3900, the capacity of this system is only 85,000 cubic feet of air per minute. It was calculated that the capacity of the system could be in¬creased to meet the demands of the current mining program in this section of the mine by utilizing a single, straight, horizontal air course on the 3200 and by driving an inclined air raise 740 feet long between the 3900 and the 3200.

Jan 1, 1967

By Thys B. Johnson

This paper presents a new algorithm for solving the Controlled Flow Mine Ventilation Problem in an optimal manner - minimum power consumption. The use of booster fans and restrictions on the locations of ventilation regulators are dealt with in a straightforward manner. This new approach is based on a common Operations Research algorithm for which there are many fast computer programs available.

Jan 1, 1982

By Dave D. Ferris

Today the coal industry is beginning to use some very fundamental economic evaluations to determine the most economical circuit to produce a specified saleable product. The fundamental economic methods used are standard return on investment and net present value calculations. By utilizing these economical evaluations, one can justify a larger capital expenditure and realize more return for an investment over the life of a coal property.

Jan 1, 1983

By S. J. Swan

A computerized on-line process control system designed to monitor and control the seven-cone copper precipitation operations at Kennecott Copper Corporation's Chino Mines Division in New Mexico has been continuously operating since April, 1972. The cone monitoring system consists of plant sampling components, process measurement instrumentation, on-stream X-ray spectrometer, control computer, typewriters for programming and for operating reports, foreman's communication console, and cone automation hardware. The system provides the following functions: (1) assays for copper and iron from ten process streams on a continuous rotating basis, (2) directs hardware to automatically flush and start up cone units based on measured performance variables, (3) provides continuous plant operating data and calculates metallurgical averages as well as production figures for shift and daily summaries, and (4) provides data logging capabilities. The system is very reliable and improves plant performance by increasing yields, reducing scrap iron consumption, and reducing operating manpower requirements.

Jan 1, 1975

By V. F. Hollister

Epithermal gold deposits occur in and near the marginal fault that circumscribes the Goldfield, Nevada, Tertiary caldera. The gold occurs disseminated in alunite, pyrite, and kaolin- bearing silicified zones that are controlled by the circular faults. Other Tertiary calderas (i.e., Summitville and Red Mountain No. 3) have epithermal disseminated gold deposits located in and near their marginal circular faults in settings that resemble the Goldfield example. These additional caldera- controlled epithermal gold deposits are also characterized by alunite, pyrite, and kaolin-bearing silicified rock that act as hosts for the gold disseminations. The Goldfield District is therefore an exploration model for those seeking disseminated epithermal gold deposits in a caldera setting.

Jan 1, 1986

By William W. Leathen

Acid mine drainage became a reality through the exposure of the first bituminous coal seam, either by man or by nature. At first the small amount of acid formed was quickly and efficiently neutralized by basic rock strata and by neutral or alkaline water. As soon as extensive mining operations overtaxed nature's own defensive measures, acid mine drainage became a problem of concern to government and the coal industry. It was the purpose of the studies conducted at Mellon Institute to accumulate knowledge, both applied and fundamental, relating to the formation and disposal of acid mine effluents. It was during this program that the microbiology of acid mine water was studied. Most bituminous coal mine effluents are highly acidic and contain, along with other ions, high concentrations of ferrous iron. The acid is sulfuric, and. the iron is present as the sulfate; both are the oxidation products of iron sulfides (FeS2) which are present in the form of pyrites, marcasites, or other sulfuritic minerals. The oxidation occurs, in the absence of moisture, according to the following reaction: [ ]

Jan 1, 1959

By C. R. Peterson

A cutter vibration monitoring system is described which would map seam strata non-uniformities to permit guidance within the seam. An extremely simple and rugged transducer is used which is compatible with conventional cutters and cutter replacement practices, and believed to be suited to the mining environment. Laboratory tests show that the system can detect bedding planes in otherwise homogeneous material. A data display system which would employ the human operator's natural pattern recognition skill and judgement will be developed, Intended for remote control applications in general, the system is of direct interest for today's continuous excavators in coal or in any other machine excavated bedded deposit.

Jan 1, 1985

By E. W. Davis

This paper deals with the role of the Maintenance Department in a milling operation; specifically, the Mines Development, Inc., processing plant at Edgement, South Dakota. The goal of very maintenance department is the smooth and uninterrupted operation of the plant it serves, To achieve this goal, maintenance men adapt various features and procedures into a program designed to fit the characteristics of their particular plant operation. A few of the basic elements of a sound maintenance program are: 1, A periodic preventive maintenance schedule. 2, A systematic inspection and lubrication procedure. 3. A training program for maintenance personnel. 4 A good equipment-history file system, 5. A carefully planned spare parts inventory.

Jan 1, 1962

By J. A. Bartnik

In recent years, the need has become more and more accute for a high capacity, high intensity, wet magnetic separator for the concentration of finely ground, paramagnetic minerals. As a result of this increased interest, extensive test work has been conducted at our Central Test Laboratory, and the basic design for such a separator has been established. Three units have been developed to comprise a full line of this equipment: (a) Series 4L (laboratory), Figure I, is manually operated to permit maximum flexibility and precise control of each variable, with a capacity of 4 gallons per minute. (b) Series LOCC, Figure II, functions by automatically controlled feeding and washing cycles, and has a capacity of approximately 1.0 tons per hour. (c) Series 200CF, Figure III, basically consists of an annular pole box, rotating through the high intensity magnetic field. This unit has a capacity of approximately 20 tons per hour.

Jan 1, 1966

By Robert M. Cox

Systematic roof bolting has proven to be a very effective method of mine roof control; however, major roof failures still occur and roof falls still remain the number one occupational hazard of underground miners. Why do some bolted mine roofs fail, while the vast majority of bolted mine roof remains stable and safe to work under? Observations of numerous roof failures indicate that most of the major roof failures* are associated with either: 1) Jointing, faulting or other structural fracture zones; 2) massive shale beds of lenticular structure, or 3) thinly laminated sand-shales. The jointing and faulting present an obvious weakness in the roof rock structure; whereas, the massive shales and laminated sandy-shales create a roof structure with low shear strength and/or modulus of deformation. An observation of major significance is that most bolted mine roofs fail as a unit, and that the thickness of the fall is roughly equivalent to the roof bolt length (See Figure 1). In fact, several operators have experienced the phenomenon of an increase in roof fall thickness with an increase in roof bolt length.

Jan 1, 1973

By A. E. Hunt

Over the past twenty-live years since large scale truck haulage in open-pit mining began, the periodic introduction of Larger capacity vehicles has provided increased productivity and reduced costs. WISEDA Ltd. has introduced a 220 ton capacity, two-axle rear dump, diesel-electric truck for the world-wide large open-pit mining industry. Design features and components selected in the development of this vehicle will be presented along with operating experience and a brief history of rear dump truck evolution.

Jan 1, 1983

By Frederick J. Hoppe

The productivity or usefulness of a Front End Loader rises rapidly with its size. Loading is more aggressive. Mother Nature is defeated more easily. Larger tires get a better grip on the ground. Hauling equipment can be loaded more quickly. The productivity or usefulness of a Front End Loader is proportional to its working speed, both automotive and hydraulic. The price of speed is horsepower, which rises rapidly with speed. Horsepower saved shows up as increased productivity. This paper covers the development of the D600, KW-Dart's articulated loader, which combines massive size with new concepts to increase its working speed. Featured is a discussion of the horsepower saving, "Balanced Boom."

Jan 1, 1969

By Bruce F. Bohor

Silica sand has been mined in Illinois from the St. Peter Sandstone since the turn of the century, especially in the area around Ottawa on the Illinois River in the north-central part of the state. Production of this sand, consumed mainly by the glass and foundry industries but also sought after for many other uses, has grown with the economy, and last year's output in Illinois exceeded 4,000,000 tons. Such an important commodity was given the early attention of the Illinois State Geological Survey, and a very complete report was issued in 1928, authored by J. E. Lamar. The mining and processing of the sand has changed very little during the intervening 40 years, so that much of Lamar's data and descriptions are applicable today. More recently, the stratigraphy of the St. Peter Sandstone in north-central Illinois has become better known from the work of Willman and Payne (1942). The present authors have borrowed generously from Lamar's publication, and we wish to acknowledge the contribution of both of these studies to our work.

Jan 1, 1969

By T. K. McMahon

Formally, a mathematical model could be defined as: A set of equations whose solution will approximate the response of a physical process or system to a set of stimuli which appear as parameters in the equations. The purpose of a mathematical model is to permit the rationalization of experience to proceed by simulation rather than by physical experimentation. In the application of digital computer control to an industrial process, the mathematical model of the process (subsequently called the process model) is needed to calculate the present process performance from the measured variables and to predict the response of the process to a control change. Functionally, the cardinal element in process model development is a concise set of control objectives. These, besides implicitly defining the boundaries of the system to be modeled, will determine the accuracy demanded of the model its nature: dynamic or steady-state, and so forth, The objectives should explicitly define what process efficiencies, production rates, qualities are to lie within the scope of the computer control project, thereby providing a basis for simplifying assumptions in the development of the model. This requirement, a limited set of control objectives, is so often disregarded in formulating industrial control problems that its repetition can scarcely be avoided.

Jan 1, 1965