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By C. L. Sarff

[Automation has become a word that means many things. To management it is the end of the rainbow; you push a button and all your problems are solved. To the working man it is a horrible monster that is taking his livelihood away. To the maintenance man it is a complex that overwhelms him when he thinks of trying to find the trouble when the machine is not operating, properly. Automation has been with us in the coal nines for many years. Long before my time you were using float switches on mine sumps to control the level of the water. That?s automation in the truest sense of the word, but we call it automatic and think nothing of it. If we use the word automatic instead of automation your mine electrician and mechanic will take hold of the problems in stride.]

Jan 1, 1962

By B. J. Arnold

Prior laboratory work has demonstrated -that much of the fine ash-forming minerals entering a flotation froth are there as a result of water carry-over from the bulk contents of the flotation cell (Arnold and Aplan, 1986a). Using a bank of four 300 cu ft WEMCO flotation cells cleaning a well-liberated Lower Kittanning seam coal, test results show that the sulfur and ash content of the froth is directly related to the water content of the froth (or inversely related to the percent of solids in the froth). Reagent changes which result in a watery froth produce a higher ash content in the froth. A direct comparison of laboratory and plant results show that the standard laboratory flotation test produces a product higher in sulfur and ash than that produced in the plant. Caution should be exercised when extrapolating laboratory test results to the plant situation. A method of estimating coal flotation product quality in the plant based on laboratory tests is given.

Jan 1, 1990

By R. L. Miller

Two samples of iron enriched basalt (IEB) containing simulated nuclear fuel and having two distinct microstructures were prepared and tested for uranium recovery. The IEBs are refractory towards leaching by ground water. However, the uranium content (15.8%) is high enough that if aggressive leaching techniques are used for uranium recovery, these materials could be considered as man-made uranium ores. The IEBs discussed in this report were prepared to simulate Three Mile Island-2 core debris. The crushed IEBs were treated using three different methods simulating potential industrial scale processes. In one method the IEBs were fused with sodium hydroxide then the cooled mass leached first with water then with dilute sulfuric acid; about 52% of the uranium was recovered in this case. In the second method the IEBs were treated with a sulfuric acid/hydrogen peroxide lixiviant and about 13% of the uranium was recovered. In the third technique the IEBs were leached with a sodium carbonate/sodium bicarbonate/hydrogen peroxide solution. Only about 0.1% of the uranium was recovered. The results of these screening tests suggest that the IEBs can be successfully treated for recovery of the contained uranium. Other studies would be required to determine if other values, such as zirconium or silver, could be recovered from the IEBs.

Jan 1, 1984

By Bruce C. Trent

In order to effectively model subsidence caused by underground openings, a two-dimensional computer code has been developed which couples near- and far-field response. The near-field is simulated by a discrete element block code and a finite difference code represents the continuum region in the far-field. The explicit equations allow rapid and inexpensive solutions to geometries which may lead to subsidence. Two sample problems are presented which illustrate the important features of the code.

Jan 1, 1979

By George A. Lawrence

A new super-large 100 m3 (3500 A3) pneumatic mechanical flotation cell is now available to meet future mineral processing challenges. Several innovative design concepts represent a marked departure from conventional flotation cell designs. The radial discharge from the pump action rotor and the overhung vane type stator is contained in a conical bottom cylindrical tank with no dead comers. Peripheral launders collect froth overflowing the entire circumference of the tank and these launders are of a hexagonal design permitting cells to be nested together in a honeycomb fashion. This new flotation cell is powered by a custom designed hydraulic motor package that provides infinite speed control in individual cells and a soft start under load

Jan 1, 1993

By Sureshan K. Moothedath

This paper provides a mechanistic representation for floc formation, growth and degradation and presents results from an experimental study of batch flocculation in which step changes were made in the impeller speed, flocculant addition, and slurry concentration. A discussion of the experimental results is included in terms of the mechanisms of floc formation and size-change.

Jan 1, 1993

By A. P. Gentsch

Commercially mined calcium carbonate is normally found near the surface in the United States. It is nun& either by open pit or underground methods, depending upon its geologic setting. Processing ranges from simple crushing to the more sophisticated ultrafine processes. Intermediate steps are pulverizing, screening, beneficiation, classification, fine and ultrafine grinding, and surface treating. These processes are performed both dry and/or wet resulting in powdered or slurry end products.

Jan 1, 1986

By Willard A. Murray

Investigations of underground coal gasification (UCG) have been actively pursued by the U.S. Department of Energy since the early 1970s; the Lawrence Livermore National Laboratory (LLNL) conducted its first field experiment in 1976. In conjunction with field and laboratory studies of the process of recovering energy in the form of combustible gases from the burning of coal deposits in situ, an extensive environmental program has been conducted at LLNL under the auspices of both the U.S Department of Energy and the U.S. Environmental Protection Agency. This program has focused on groundwater contamination and ground surface subsidence caused by UCG. The material presented in this paper is a summary of results from the environmental studies of UCG activities conducted by LLNL as described by Mead, et al. (1981) and supplemented by the author's experience with this program in 1980 and 1981. The following sections describe specific groundwater contamination and surf ace subsidence problems encountered during field experiments in northeastern Wyoming, and will discuss implications of preliminary findings from geohydrological investigations of a site in southwestern Washington. Finally, possible environmental control technologies that are most likely to be effective in mitigating environmental impacts are discussed.

Jan 1, 1982

By B. W. Lawrence

Shaft alignment requirements are consistently met using conventional shaft sinking methods. Little attention has been given to achieving similar alignment accuracies using rotary drilled shaft methods. Alignment of these shafts is difficult to control and guarantee. Bare shafts and shafts that use drum hoisting systems can accept some deviation. However, combining drilled shafts with Koepe hoist installations presents new accuracy requirements for drilled shafts. This paper describes the importance of verticality with practical examples, and discusses various methods of measuring verticality and their respective limitations.

Jan 1, 1989

By Mehmet Guney

[The Atlantis-II-Deep is a hydrothermal mineralization located along the median valley of the Red Sea at a water depth of about 2200 m. Extensive exploration of the metal-rich brine deep revealed a potentially mineable deposit on economic interest consisting of oxides, silicates and sulphides with considerable concentrations of zinc, copper, cadmium and silver. Geostatistics was applied to assess the most likely in-situ vague of the metal potential for economical exploitation. Semi-variograms were constructed to characterize the structure of the regionalized distribution of the geological parameters. Volume grades and thicknesses were determined by the kriging technique, avoiding systematically biased high or low grades, and then block .tonnages were computed. The estimation variances, distribution of errors and histograms of observed and kriged values in each grid Mock were also produced.]

Jan 1, 1983

By H. A. Zollinger

The Hallmark Distribution Center is one of the most sophisticated material handling and order filling facilities in the world. The 53 million cubic foot facility houses an ultra-modern, computer- monitored distribution complex that handles as many as 1/4 million orders per day. The Distribution Center replaces 16 leased buildings scattered through- out metropolitan Kansas City and, in addition, re-leased 4 floors in mid-town Kansas City needed for creative and administrative expansion. This new facility is the nerve center for distribution of Hallmark products in United States and Latin America. The size and gross numbers of all parts of the system is a significant accomplishment, but the purpose of this paper is to explain the technical advancements in the state-of-the-art of material handling and controls. The system iteself is made up of seven sub-systems including receiving, warehousing, picking rack stocking, towline, order filling, order sorting, and shipping. Significant techniques were used in each of these areas as well as technical advancements in the state-of-the- art. The most significant points are in 4 of the areas and are discussed in this paper.

Jan 1, 1973

By Hugh Boyd

Jet pulverization is a relatively new tool for fine grinding. It is not yet in general use in the mining and ore dressing fields, since most of the requirements in these areas have been for relatively coarse particle sizes. As the need for finer grinding increases - because of different ores, new products, and new values being sought - jet pulverization will, increasingly, be properly used.

Jan 1, 1969

By Takahide Wakamatsu

In Japan all the complex sulfide ore deposits of base metals have been developed as underground mining. The underground mining cost is extremely high as compared with open pit mining case. Therefore, in milling section of base metal mines, technical advance for maximum recoveries of valuable constitutents in ore has been required all the time to utilize as much ore mined as possible. At present, in mill plants treating "Kuroko", complex sulfide ore, concentrates of copper, lead, zinc, pyrite and barite are produced, with gold and silver contents in the copper, lead, and zinc concentrates being estimated as extra profit. As in the case of Kuroko milling plants, gold and silver contents in the lead and zinc concentrates of lead-zinc ore milling plants are also varuable from an economical viewpoint. Silver content is very high in Kuroko crude ore as well as lead-zinc ore.

Jan 1, 1982

By V. Svalbonas

Presently the U.S. mining industry is very conscious of costs. It is timely, therefore, to review the dominant specifications used in the industry for procuring large size-reduction equipment. These are compared with other specifications and procurement methods, such as ASME and DOD, using the criteria of resulting costs, safety/ quality, and fitness-for-service.

Jan 1, 1987

By Shosei Serata

In the past, salt cavities for storage of liquid and gaseous fuels have been developed and operated using practical experience as a guide rather than rock mechanics principles and practices. Although many salt cavities are still operating satisfactorily. some of them are beginning to show various problems associated with long-term deterioration of the cavities. This paper describes a major breakthrough in the rock mechanics design of solution cavities which is the development and application of the REM computer simulation system. From the computer simulation analysis, the long-term deterioration process of cavities can be related to the basic parameters of rock mechanics design and the storage operations. The computer simulation system is also used for optimizing cavity design and operational specifications. This optimization technique is explained by its application to the three basic storage systems: 1) open dry storage system for liquids and solids 2) open wet storage system for liquids 3) pressurized storage system for gases, liquids and solids The effectiveness of the optimization technique is illustrated with some field examples by showing the direct interaction between the computer simulation system and field data of a test well including tectonic stress conditions, material property coefficients and geological anomalies.

Jan 1, 1974

By V. B. Achanti

Reliability of the compressive strength of a coal seam determined in the laboratory is often subjected to debate. Effects of the coal seam's inherent characteristics, specimen preparation, testing procedure, testing condition, and a number of tests often result in drastic variation of the strength data. This paper deals with the development of a testing procedure for determination of coal seam compressive strength in the laboratory. Coal samples from two different coal seams were tested. First, the inherent characteristics of each coal seam such as coal structure, Hardgrove Orindability Index (HOI), Slake Durability Index, proximate analysis, and mechanical properties namely Young's modulus and Poisson's ratio were determined to categorize them in terms of their characteristic severity liable to produce variable strength data in typical laboratory tests. Second, two commonly used laboratory specimen shapes namely; cylindrical and cubical, were tested to determine which shape produced the least variation of data and reproducible strength values. Third, four loading rates within the static testing range (Le. 0.007 MPa/s (1.0 psi/sec), 0.07 MPa/s (10 psi/sec), 0.34 MPa/s (50 psi/sec), and 0.7 MPa/s (100 psi/sec)) were used to determine an ideal loading rate. Finally, the number of test samples required to produce strength data within the acceptable standard deviation, considering coal seam characteristics were established.

Jan 1, 1996

By Dominique Francois-Bongarcon

The world mining industry is facing a severe recession. Thus, it is time to recall the value of geostatistical methods which were formerly developed as a money-saving and productivity-increasing tool. The situation has worsened, but the techniques of geostatistics have dramatically changed. Up to millions of dollars can be saved during exploration with simple use of variograms; then, during reserves estimation with kriging methods; and finally, with the parameterization of reserves, when evaluating a project and optimizing its global mining parameters.

Jan 1, 1983

By Eugene E. Brucker

In recent years, there has been increased interest in construction problems presented by karst topography. Twenty-five years ago, karst areas were by-passed for development. Today, the high cost of land and population pressures are requiring utilization of karst areas. Areas exhibiting karst features can be satisfactorily developed so that construction can proceed in a normal manner; or the areas may be left undeveloped and the underground drainage system abused by improper use causing or contributing to structural collapse, excessive erosion, and a grave threat to the stability of land development and the environment. The term "karst" is a comprehensive term applied to areas underlain by soluble rock that possess a topography formed chiefly by the dissolving of rock and the diversion of surface waters to underground routes. There are four features which contribute to the maximum development of karst. 1. A soluble rock, preferably limestone, must be present at or near the surface of the ground. Occasionally, dolomite will suffice.

Jan 1, 1970

By William M. Warren

Recent sinkhole activity in carbonate terranes of Alabama has resulted in damage to transportation lines, structures, utility lines, and property in general. Active sinkhole development and subsidence has been well documented in Alabama, Florida, Pennsylvania, and South Africa. An excellent example of the potential danger resulting from this activity is the spectacular collapse under a South African gold ore crusher plant that resulted in the death of 29 men in 1962. Due to the severity of the problem in certain localized areas in Alabama, a detailed investigation is being undertaken by the Geological Survey of Alabama and the U. S. Geological Survey. One of the most promising techniques is the application of aerial photography and thermal infrared imagery. Conventional and modern remote-sensing techniques are being used in Alabama to locate and define areas of sinkhole activity and to determine which areas are most prone to its occurrence.

Jan 1, 1975

By Robert W. Carn

This paper presents the concepts which are presently being utilized in the design of coal export terminals. Criteria for selecting a viable site and establishing the terminal plan are presented. Factors affecting the design of the terminal as well as the present techniques and procedures in use today to determine the optimum use of equipment will be discussed along with the current trends in export terminal control systems. Finally capital and operating costs for a typical export terminal are reviewed.

Jan 1, 1982