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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 George W. Leney

The iron ore industry might justifiably claim to have originated the science of geophysical prospecting. Their use of geophysical methods was probably the first application of these scientific techniques to the search for economic materials although the exact origin is undoubtedly lost in the unrecorded observations of. some prospector experimenting with compasses or bits of lodestone. Since 1879 when Thalen published "On the Examination of Iron Ore Deposits by Magnetic Measurements" these methods have been a standard supplement to other prospecting techniques. However, many of the great ore bodies of the Precambrian iron ranges were not particularly suitable for geophysical work. The ores were oxidized and enriched through leaching of silica so that they were nearly non-magnetic and other physical properties which distinguished them from the wall rocks were largely destroyed. With the gradual exhaustion of these high grade direct shipping ores, and ores that could be beneficiated by simple means, the iron ore industry turned initially toward the importation of similar high grade foreign ores. At the same time, new processes for concentrating lower grade materials were being developed and older ones improved upon. These concentrates' when pelletized produced such important savings in blast furnace hot metal costs that they now command a premium in the iron ore market and have weakened the competitive position of the remaining high grade ores. The ore bodies now being sought are usually unoxidized and frequently they are also metamorphosed.

Jan 1, 1965

By David B. Cook, James R. Bieke

I. INTRODUCTION Lawyers are a cautious breed; and it might be expected that a paper concerning a broad and complex area of legal regulation, prepared by lawyers for presentation to a predominantly non-legal audience, would commence with several caveats. Ours are the following: First, we have written a broad (and, in some instances, simplified) overview of the regulatory system and of some of the more important requirements generally applicable to uranium mine and mill wastes in the United States. Our paper is not a legal opinion setting forth all of the governmental requirements that would have to be met by any particular mine or mill. Similarly, we do not imply that the requirements we mention are necessarily applicable to each and every mine and mill in the country; depending on the facts, some of the requirements may be inapplicable or avoidable through exemption or variance proceedings. Compliance decisions and strategies for particular facilities must be considered on a site-specific basis. Second, we have undertaken merely to describe the regulatory framework and some of the generally "applicable" requirements which have been promulgated and proposed by administrative agencies. We express no opinion on whether, under the U.S. Constitution and statutes, the existing and proposed agency regulations are valid in general or as applied to any particular mining or milling operation. There are, of course, procedures for judicial review of agency action; and newly promulgated environmental regulations have frequently been challenged, with varying degrees of success, before the courts. For us even to begin to consider such issues would expand an already forbiddingly long paper to totally unmanageable proportions. Third, in light of the subject of this Conference we have limited our paper to the legal framework and requirements applicable to uranium mine and mill "wastes" -- primarily mine overburden and waste rock and mill tailings (including waste tailings solution). We treat operating discharges (e.g., emissions from yellowcake drying) only peripherally. Fourth and finally, it is important to note that this paper, at least in so far as it concerns the specific requirements of particular regulations, will likely soon be out of date in some important respects. Despite

Jan 1, 1980

By F. H. Mertens

The costs of an open-pit operation can be classified according to the following hierarchy : -overall cost of production (per ton of ore) -costs of basic operations and functions -costs of auxiliary operations -costs of machines and equipment -maintenance costs. Production cost is a measure of the open-pit mine performance and should be the final target of the management control. It is also a measure of the share of the mine in the processing stages.

Jan 1, 1990

By P. R. Taylor

This investigation (Bowles, 1990) involves consideration of technology utilized by three separate fields of metallurgy and materials science: 1) The recovery of metals employing the use of solvent extraction, 2) The fabrication of materials using powder metallurgy, and 3) The use of composite materials in fabrication of engineering materials. The research considers each of the processes in order to realize the benefits of each. In light of the fact that materials have an intended use -it does seem plausible to simplify the process required between "mother earth" and final use. For instance, a primary copper producer that already employs a solvent extraction and electrowinning process could produce value added products directly. Part of the existing extractant flow could be diverted into a pressurized hydrogen stripping process in order to produce specialty composite powders. Innumerable methods have been employed for the recovery of metals; solvent extraction, the one considered in this study, was used due to the possibility of it providing a pure powdered metal. The use of solvent extraction in the recovery of metals has gained wide acceptance and its use proves beneficial in many applications (Ritchey and Ashbrook, 1984). Pressure hydrogen stripping of solvent extractants may provide the benefit of flowsheet simplification compared to conventional solvent extraction followed by electrowinning. It may also provide the benefit of direct production of high purity metal powder (Demopoulos and Distin, 1985).

Jan 1, 1992

By Y. Guan

The dissolution behavior of silver and copper from silver/copper alloys in ammoniacal solutions has been investigated using a rotating disc. Oxygen was used as an oxidant. The effect of composition of alloys, concentration of lixiviants, stirring speed and temperature on the overall dissolution kinetics has been studied. Silver / copper alloys of three compositions were used in this study. The atomic percents of silver in these alloys were 76.9, 46.9 and 24.1. The results on the rate of dissolution obtained for these alloys have been compared with that of pure silver and copper under the same testing conditions. A particular emphasis has been given to the galvanic effect on the overall dissolution rates.

Jan 1, 1993

By R. A. Pimentel

Many longwall operators experience difficulty complying with the federal regulation limiting average dust exposure. Others are currently in compliance, but the dust exposure limit keeps then from increasing their production. Spray water is a major means of dust control. Excess water can cause problems in the transportation system and the cleaning plant, and reduces the Btu value of the run of mine coal. Thus, the dust exposure reduction per unit of water sprayed must be maximized. This paper discusses underground tests recently completed as part of a Bureau of Mines research program to determine the effects of variations in spray water flow rate, pressure, proportioning and spray orientation on longwall shearers.

Jan 1, 1984

By Pedro Sanchez-Mejorada

Laguna del Rey is the name of a dry lake bed located in the State of Coahuila, Mexico in a semi-desertic terrain typical of the basin and range physiography. Química del Rey, S.A., a subsidiary of Industrias Peñoles, has been producing sodium sulphate since 20 years ago, from brines pumped from the sub-surface of the present playa. The spent brine is used as raw material for the production of magnesium oxide. An extensive, lenticular deposit is found just below the playa. It consists mostly of glauberite (sodium-calcium sulphate) and blöedite (sodium-magnesium sulphate). The glauberite occurs as thin crystals oriented at random and leave many void spaces among them. These intercrystalline spaces are partly filled with mud, but the whole mass of the evaporite is still very porous. A brine that contains in solution ions of sodium, magnesium, sulphate and chlorine occupies the voids of the sponge-like evaporite body.

Jan 1, 1984

By R. L. Grayson

As the total cost of labor has significantly increased over the past ten years, older underground mines have found it more difficult to compete- in a limited demand coal market. Many of the older mines were developed extensively into a reserve requiring a large number of workers to maintain and rehabilitate extensive track haulages and/or belt conveyor systems. Often, a large number of fans were required to maintain minimal airflows in areas where poor conditions and huge leakages prevail. This paper focuses upon problems which beset one such coal mine and projects undertaken to restore it to potential profitability.

Jan 1, 1986

By G. W. McCaa

Plans for a large industrial development in the Upper Ohio Valley between Moundsville and New Martinsville, West Virginia, were announced in the Fall of 1955. This development consisted of a large aluminum plant to be .built by Olin-Mathieson; a 675,000 KW power plant to be constructed by the American Electric Power Service; and a large coal mine adjacent to the power plant to be developed by the Hanna Coal Company Division of Consolidation Coal Company. The Ireland Mine was designed to efficiently supply fuel for the power plant, and this was the first consideration in the location of facilities, design, and development of plant and the selection of the equipment. The first problem was to find a suitable area for the surface facilities. A level bottom area south of the power plant was reserved for future industrial plants and this area was also blocked off from the coal reserves by an old abandoned and flooded mine. The coal storage facilities of the power plant were on the north side of the plant and it was decided to locate the coal mine preparation plant on-the shoulder of a hill above the power plant. This location required the excavation of 70,000 yards of rock but permitted the driving of a belt slope from the plant at an angle so that the haulage roads underground would miss the abandoned Cresap Mine. This location also permitted the plant to be located at an elevation so that the conveyors leaving the plant were horizontal and had sufficient clearance above the highway and railroad tracks. The other surface facilities consisting of air shafts, supply slope, supply yard, office, bathhouse, shop and warehouse were located in the valley some distance north of the preparation plant. This location placed these facilities one mile nearer to the working area. Plans for design and development of the mine were started in November 1955; grading and clearing of surface area was started in January 1956; the air shafts and slopes were started in the Spring and Summer of 1956; and the first coal was produced from the supply slope in October 1956. The preparation plant was put in operation in March 1958, and by July 1959 was producing 8,000 tons per day.

Jan 1, 1959

By A. Norholm

For grinding Portland Cement, the power consumption accounts for some 35 % of the total consumption of electrical energy for producing cement, counting right from the quarry to the packing plant. It is therefore for very good reason that great efforts during the past years have been put into making cement grinding more efficient, thereby saving power. In this paper three ways of reducing the consumption of electrical energy will be described, namely precrushing in the high pressure FLS-Köppern roller press, the introduction of a new design of COMBIDAN diaphragm in ball mills and the separation of mill discharge in the newly developed high efficient; separator SEPAX from F. L. Smidth.

Jan 1, 1987

By I. Iwasaki

The presence of calcium ion in iron ore pulps causes heterocoagulation of montmrillonite on hematite leading to indiscriminate dispersion. Two methods were investigated to control the adverse effect of montmorillonite: chemical method using such complexing agents as EDTA and sodium tripolyphosphate, and mechanical method involving ultrasonic treatment. Their roles in controlling the adverse effect were investigated by zeta potential measurements, starch adsorption tests, and flocculation and selective flocculation tests.

Jan 1, 1986

By B. Waquet

The genesis of a hydrothermal subsea mound, by chimney debris heaping and mineralizing fluid circulating upward, induces a vertical maturation gradient. Connected porosity is easy to measure and, after mineralogical evidence, can be use as a maturation index. Thus, to understand how a rock property evaluates with maturation, it is possible to plot it against connected porosity. Results are that uniaxial compressive strength, Young's modulus, and in a lesser certitude tensile strength, abrasivity and hardness, increase very weakly with maturation until a maturation threshold (equivalent to a connected porosity equal to 0.2), and rocket to much higher values after it.

Jan 1, 2011

By J. F. T. Agapito, L. J. Gilbride

High horizontal stresses were recognized to impact roof stability more than 60 years ago. Since then, numerous measurements associated high horizontal stresses with difficult ground conditions. This paper presents case histories illustrating the practical usage of roof stress determinations for helping assess stability, not only in the case of high horizontal stresses but also of low stresses. Examples are given of high stresses associated with faults, mine design changes, quantification of stress shadow effect, and anistrophy. The paper concludes with a comparative evaluation on the effect of various stress fields on ground support requirements.

Jan 1, 2002

By George C. Carter

It was just a little over three years ago that the "Go" button was pushed to start operations on the blending piles at Oro Grande. As is usual with any new installation, there were problems that had to be solved. This paper will concern itself with those problems directly related to quality control. To obtain a consistent outgoing quality level at the most economical level for a finished product requires two main points: 1. Measurement of variations in the process, 2. A method of making a predictable change to adjust for variations. The manufacture of cement requires a relatively high degree of accuracy if a consistent outgoing quality level is to be maintained. The blending piles were our solution to this problem.

Jan 1, 1962

By James J. Scott

Shale formations are the Nemesis of the Mining Engineer. Shales react to changes in environment in the most unusual and unpredictable manner. Increase in temperature may cause spalling, increase moisture and compression induced fractures may occur, and if a full face is exposed it may deteriorate due to atmospheric exposure. Combine only small amounts of shale in layered fashion with hard brittle competent rock and the whole structure may be fractured and fail due to stresses generated in and around the shale. In this paper the author will discuss failure mechanisms encountered under various field conditions and remedial action which may be employed by the engineer.

Jan 1, 1969

By Ronald M. Tipton

Freeze and thaw deterioration is a serious problem In con¬crete pavements. The main cause of distress Is thought to be the pore structure of coarse aggregate. In an attempt to characterize deleterious pores, the Iowa Pore Index test and the Expected Durability Factor, as Calculated from the mer¬cury intrusion porosimeter, were devised. This study Included freeze-thaw and sodium and magnesium sulfate soundness testing of sixteen carbonate aggregate samples. In addition, the Iowa Pore Index and the Expected Durability factor were determined for each of the samples. All of the Above mentioned physicochemical parameters were examined using bivriate correlation analysis with the In¬tent to evaluate the effectiveness of the Iowa Pore Index and Expected Durability factor for predicting the frost dur¬ability of an aggregate. The results from the bivariate correlation analysis showed no significant correlation, between the Iowa Pore In¬dex And- Expected Durability factor with the other physico¬chemical parameters investigated. Rust interesting is that the Iowa Pore index predicted that All of the tested samples would resist freeze-thaw failure, whereas the Expected Durability factor predicted that -ash sample would he non-durable.

Jan 1, 1987

By Todd S. Harris

Industrial minerals or non-metallic minerals are loosely used terms applied to a diverse assortment of materials which, in many cases, have nothing more in common other than the fact that they are neither metals nor fuel minerals. To help bring order to this otherwise random assortment of minerals, we have grouped these materials into two main categories; chemical and physical minerals, and nine sub-categories based on end-use applications as shown in Table 1. Chemical minerals are products which are principally used for the specific chemical elements they contain, whereas physical minerals are products which are used to meet specific performance specifications. The latter part of the 1970?s, in particular 1978, were considered peak years in terms of production and sales for many industries, By using 1978 as a base year, we can evaluate wherethese markets stand today after the recession of the early 1980's and the recovery which began several years ago. From this historical overview and appraisal of the current situation, various assumptions can be drawn as to which markets are expected to perform well into the 1990's.

Jan 1, 1987

By A. D. Randolph

Comminution represents one of the major costs of mineral recovery from low-grade ores. Efficient mineral recovery in a typical low-grade ore grinding-flo¬tation process depends on grinding the ore small enough to liberate mineralization without producing excessive slimes, which would result in higher power and flotation reagent costs. Size criteria for efficient grinding should be stated in terms of the distribution of mineralization sizes, but as the mineralization-size distribution is difficult to determine, less desirable criteria of absolute particle-size distribution (PSD) are used in practice. Thus, there is considerable incentive to be able to analyze and predict the PSD performance of grinding circuits for control and optimization of the process. Any realistic model of a grinding circuit must account for recycle of oversize material; such oversize recycle adds to the total mill load and limits total production rate. Simulation of such closed-circuit operation to study grind factors affecting total throughput can be done in a straightforward fashion provided recycle calculations can be added to an accurate input-output model of PSD in the grinding mill itself. Such a total simulation of mill performance is of obvious practical value in assessing the practicality and benefits of various over-all mill control schemes and/or modes of operation. For example, considerable interest has been shown in the development of continuous on-line particle-size sensors and such instruments should be an operating reality in a few years. A total closed-circuit PSD model of this type would be invaluable in the utilization of, and in predicting the pay-out from, such an on-line particle-size sensor. The purpose of this paper is to present a new approach to the development of an input-output PSD model of a grinding mill. The model is continuous in the par¬ticle size coordinate, L, and is based on the principle of a particle population balance along the particle size coordinate. Most previous studies of the grinding unit operation attempt to relate power

Jan 1, 1971

By M. A. Girts

Wetlands can be constructed inexpensively on mined lands to treat small flows of acid mine water. Metals are removed from the water by the wetland vegetation and indigenous bacteria. Full-scale field tests initiated at over 20 mine sites during 1984 and 1985 indicate that water quality can be upgraded to meet discharge standards with relatively minor maintenance requirements. Iron concentrations of 25-85 mg/L in the influent water fall to less than 2 mg/L during flow through a small wetland. Manganese can also be removed, though somewhat less efficiently. At the discharge, pH is easily raised to 6 by flow over limestone.

Jan 1, 1986