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By John D. Wiebmer

Kansas, with its thin seams and tough overburden, may not be anyone's first choice for a coal mining operation. But there are operators making it pay through careful attention to mining techniques and aggressive marketing in the local region. One of the few Kansas coal operators is Bill Patch, who has been in the business for 28 years. Beginning with a single dragline operation near his home in Welch, Okla., Bill's Coal Co. weathered some lean times during the "soft" coal market of the 1950's and 1960's. But his tenacity paid off when new markets began opening up, and the company has grown by leaps and bounds in recent years. In 1975, the Fort Scott mine opened in Bourbon County, Kansas; in 1976, the Porter mine began production in Wagoner County, Okla.; in 1977, the Fulton mine opened near Fulton, Kansas. In addition, the original Welch mine in Oklahoma is still a producer, and this year the company will open a new mine at Chetopa, Kansas.

Jan 9, 1978

By Gunnar Almgren

Hole deviation has great consequences on mining economy, especially for long hole drilling technique. First of all the bore hole datas are concerned but also such factors as development, loss of ore and waste rock dilution are influenced. Hole deviation for sublevel open stoping is illustrated with examples from some mines. The deviations are indicated as mean values but also as standard deviation values, owing to their statistical distribution. The economic influence of the hole deviation is especially studied for steep, small lowgrade orebodies, mined with big hole blasting. Hole deviation can thus influence costs up to US$ 3-4 per ton for operating, development, losses of ore and rock waste dilution. This cost is of the same magnitude as the total operating costs for many sublevel stoping mines. The economic savings in accurate drilling are therefore substantial and are worth all attention.

Jan 1, 1981

By Thomas A. Lang, John A. Bischoff

The use of rock bolts for the support and stabilization of coal mining excavations was introduced over 30 years ago and, since that time, has progressively increased until today it is the primary means of support and stabilization of large underground openings. Early analytical studies and work with photoelastic and physical models established that even highly fragmented rock could be stabilized by rock bolting and form a load-carrying structural member that would span an opening. For stability, interaction of the bolts is essential and it depends on the bolt tension, the length and spacing of the bolts, the characteristics of the rock, and the applied load. However, the development of an explicit functional relationship embracing all these factors proved to be elusive. A review of the early rock bolting investigations led to the concept that the basic element of a rock bolted roof is the reinforced rock unit (RRU), consisting of an individual bolt and the rock immediately surrounding and adjacent to it, and to the development of mathematical equations which give the minimum bolt tension required to ensure that the RRU's are stable relative to one another and act together as a structural member. Analytical procedures have been developed for integrating RRU's into a reinforced rock structural (beam-arch) member which spans an underground opening and providing a rational basis for the design and installation of rock reinforcement systems.

Jan 1, 1982

By David B. Campbell

Production of both metallurgical and thermal coal represents a significant sector of the mining economy of British Columbia. The coal measures are located in the Rocky Mountains, and the majority of the coal is produced by open pit mining. The coal seams occur interbedded with siltstones, sandstones, mudstones, and shales. Consequently, large volumes of waste rock are generated in the course of open pit mining. The waste rock is consigned to waste rock piles that of necessity must be developed on moderate to steeply sloping terrain. Some of the waste dumps currently under development will ultimately contain in excess of 500 million cubic meters of material, and some of the proposed waste piles will attain heights in excess of 300 m. These waste piles must be developed in a manner that will assure their stability through all stages of development, as well as over the long term after mining operations have been completed. This paper describes methods of waste dump development, factors affecting stability, modes of potential failure, and a simple method for monitoring movements to provide a warning of pending unstable conditions.

Jan 1, 1985

By Dave H. Barnett, Brij M. Moudgil

The flotation technique as employed by Florida phosphate producing companies for the beneficiation of fine phosphate particles has been standardized over the years. Lower recoveries of coarse phosphate rock by froth flotation technique, however, led to the development of new methods based on skin flotation of phosphate agglomerates. Recent developments of floating coarse rock in large flotation machines have not yet convinced the rock producers of their higher separation efficiency. It is interesting to note that the selection of a particular machine is still based on equipment preference by an individual company as well as proven performance of a particular machine for upgrading a specific material. Various techniques which have been developed to beneficiate the coarse phosphate rock have been discussed. Performance of the individual techniques is presented.

Jan 1, 1980

By H. R. Thresh, A. F. Crawley, D. W. G. White

The densities of liquid tin, lead, and Sn-Pb alloys have been measured over a range of temperature above the liquidus. In all cases, data can be adequately represented by an equation of the type p = a + bT. For pure tin, the values of a and b are, respectively, 7.139 and 7.125 x 10-4, and for pure lead, 11.060 and 12.220 x 10-4. At constant temperature, molar volumes in the Sn-Pb system vary linearly with composition. DURING the course of a long-term program at the Department of Energy, Mines and Resources, Ottawa, Canada, the densities of liquid tin, lead, and Pb-Sn alloys were studied. The work reported herein draws on two sets of results independently achieved by Thresh, on the one hand, and by Crawley and White, on the other. EXPERIMENT The method and apparatus were originated by Thresh and have been described in detail in Mines Branch reports.172 In operation, the 14 cu cm graphite pycnometer is put in the furnace as shown in Fig. 1 after a machined charge has been placed inside the pycnometer and the lid screwed down. The dimensions of the charge are such that, upon melting, a small excess of liquid metal is discharged through the capillary hole to displace the weighted float above. When the pycnometer has been equilibrated at the experimental temperature, the

Jan 1, 1969

By Robert Lindsay

A NUMBER of detailed investigations of the physical changes accom-panying age-hardening have raised the question as to the possibility of some phenomenon preceding the actual process of precipitation. There is considerable evidence to indicate that in the first stages of the aging process there is a pronounced distortion of the crystal lattice. This is particularly marked in duralumin. It would be of considerable theo-retical interest to know the nature of this distortion as compared with that produced in other ways and to find out whether, in supersaturated alloys, it is a necessary antecedent to the formation of a second phase by precipitation. It was believed that a study of the age-hardening char-acteristics of a normally aged alloy compared with one that had been mechanically distorted might supply some useful information on these points. In addition, information would be obtained regarding the effect of a mechanical distortion on any subsequent stage in the aging process. Duralumin was chosen as the material for this investigation because the various aspects of its aging behavior can be shown in detail by suit-able variations of the aging temperature. Also, probably more work has been done on this class of alloys than on any other. In spite of the many published results, it was felt that the experiments would be significant only if all of the work were done on samples from the same source and if they were examined under identical experimental conditions.

Jan 1, 1939

By K. J. Miller, R. E. Hucko

The Coal Reparation Division of the Pittsburgh Mining Technology Center conducted an investigation to assess and compare the pyritic sulfur reduction potential of coal-pyrite flotation and high-gradient magnetic separation (HGMS). Tests were run on three coals - an Upper Freeport bed coal, a Lower Kittanning bed coal, and a Pittsburgh bed coal - to establish grade-recovery relationships characteristic of both processes. Representative portions of each coal sample were crushed to two top sizes-nominal - 500 pm (-35 mesh) and nominal - 149 pm (-100 mesh)-and subjected to conventional froth flotation. The froth product was then beneficiated by coal- pyrite flotation or HGMS, to provide a direct technical companion of the two processes. At - 500 pm (- 35 mesh), the size normally employed for coal flotation, both coal-pyrite flotation and HGMS effectively separated pyrite from coal, and the performance of the two processes was essentially the same. At a - 149 pm (- 100 mesh) sire, however, the performance of HGMS exceeded that of coal-pyrite flotation. The separation effected by HGMS were more efficient at - 149 pm (- 100 mesh) than at - 500 pm (- 35 mesh). On the other hand, it was concluded that either the effectiveness of coal-pyrite flotation decreases with diminishing top size or the process has not been optimized to treat material finer than 500 pm (35 mesh).

Jan 1, 1983

By Axel Sahlin

The day is long past when linen and cotton rags were the exclusive raw material of the paper-trade. Wood-fiber, chemically or mechanically prepared, straw, hemp and Esparto grass have largely supplied the demand, which the old materials did not suffice to fill. But even these newer fibers have been of late supplanted, to some extent, by mineral pulp. Weighting and filling materials have also been resorted to, partly to give body to the fabric, partly to increase its weight and reduce the cost per pound. China clay, sulphate of lime and soapstone have generally been employed as loading materials. Even though these materials lack fiber, their addition must by no means be viewed, as it too generally is, entirely as an adulteration. No doubt, to a certain extent, they weaken the paper ; but for ordinary grades the addition of these non-fibrous substances is a positive advantage, as they close the pores between the fibers and lend to the paper a great degree of opaqueness and a superior finish. Fibrous talc, as a form of pulp, has the same effect, without appreciably weakening the paper. When, therefore, some fifteen years ago, fibrous talc in large quantities, and of marvellous purity and whiteness, was discovered in the neighborhood of the town of Gouverneur, it was not long before the

Jan 1, 1893

By E. E. Krist, W. H. Sweetser

Sampling of an orebody has a number of purposes. In the initial phase, it is necessary to define the limits of the orebody and mineral content to the extent that it can be stated whether it is, in fact, an economic orebody. Also, samples must be generated so that geological and metallurgical evaluations can be made. Finally, when sufficient information concerning the geology, mineralogy, and metallurgy are known, a mining method and plan can be developed and the metallurgical; plants constructed to process the ores as they become available. With today's large, complex open pit copper mines, single sampling methods would be inadequate. Diamond drilling, percussion drilling, underground shafts and drifts all play a part in the total orebody, definition. At Anamax Mining Company's Twin Buttes mine, sampling and orebody definition.wil1 eventually lead to the existence of three metallurgical processing plants and, perhaps, an underground mining operation. A 30 000 tons per day sulfide concentrator was placed in operation in September 1969 and a 10 000 tons per day oxide leaching plant was placed into service in May 1975. The aim of this presentation is to historically discuss the orebody sampling that has been done at Twin Buttes, briefly describe the orebody, and discuss the analytical methods currently used to assist the geologist, metallurgist and mine planner in their respective evaluations.

Jan 1, 1978

By Henry Emmett Gross, David R. Mitchell, H. E. Oehler

THE production of fluorspar is one of the smaller nonmetallic industries in the United States with a capital investment-about $10,000,000. Shipments from United States mines' in 1936 totaled 176,231 short tons valued at $3,111,268, an average price of $17.65 per ton. The United States produces about 40 per cent of the world's fluorspar, of which about 90 per cent comes from the Illinois and Kentucky deposits along the Ohio River.2 Further detailed information on the fluorspar industry in the United States is given by Hatmaker and Davis.28 Fluorspar is marketed according to the following relative quantities and specifications : [ ] The concentration of the coarser sizes presents relatively little difficulty, good recoveries being obtained with jigs and tables. However, sizes smaller than about 10 mesh cannot be successfully treated by ordinary gravity separation methods and so have been accumulating as

Jan 1, 1938

By John R. Weeks, Dan McLachlan, John R. Lewis

DURING the operation of the iron blast furnace, aggregates of hard, infusible, yellow, cubic crystals frequently form in the interstices of the lining and on the hearth of the furnace. These were first examined by Wohler&apos; and were identified by him as a complex cyanonitride of titanium, having a formula Ti(CN)2 • 3Ti3N2, or more simply Ti10C2N8. However, recent investigators have suggested that this complex compound does not exist. Recent work by Hume-Rothery, Raynor, and Little2 on the carbide and nitride particles in titanium steels suggests that a complete series of solid solutions of the general type Ti<0+y>C0Ny exists between titanium carbide (Tic) and titanium nitride (TiN). Assuming this to be true, it seems likely that Wohler&apos;s cyanonitride of titanium is in reality a solid solution of 20 mol pct Tic in 80 mol pct TiN, .the nearly consistent carbide-to-nitride ratio probably resulting from temperature and pressure conditions in the blast furnace. The object of the present work was to investigate thoroughly this possibility of a solid solution by using the single-crystal methods of X-ray analysis. A spectrographic qualitative analysis of a sample of the yellow crystals furnished by the Geneva Steel Co. sh&apos;owed, in addition to the titanium, strong lines of vanadium and moderate to weak lines of iron, magnesium, silicon, aluminum, and calcium. The last five were probably slag impurities, but the vanadium was possibly included in the yellow crystals, owing to a great structural similarity of its carbide (VC) and its nitride (VN) to the titanium compounds, Table 11. A chemical analysis was made

Jan 1, 1952

By Daniel R. Shawe

Ore deposits of the western U.S. are divisible broadly into two genetic groups, a smaller one that fits the plate tectonic model of subduction and a larger one that appears unrelated to subduction. Some of the middle Paleozoic and lower-middle Mesozoic ore deposits in the western U.S. are associated with eugeosynclinal rocks and lie a few hundred kilometers west of reconstructed continent margins. These deposits probably formed as a result of subduction beneath oceanic or thin continental crust that was analogous to subduction predicated for the Kuroko massive sulfide deposits of Japan. Some middle Mesozoic porphyry copper deposits may have formed east of the continental margin when subduction-generated magmas were emplaced high in continental crust in a manner analogous to subduction-generated magmas that formed the Andean porphyry copper deposits. Most Cretaceous-Cenozoic ore deposits lie in a broad region extending many hundreds of kilometers east of the continent margin and characterized by conjugate tectonic zones, high terrestial heat flow, and low seismic velocity in the upper mantle. The deposits likely were formed in relation to magmas generated along the conjugate tectonic zones during differential northwestward drift and internal wrenching of the continental plate.

Jan 1, 1978

By R. R. Nash, W. F. Sheely

Experiments were conducted on magnesium monocrystals in order to collect quantitative information on the mechanisms which limit the rate of basal slip. Using critical shear stress and creep data, activation energies for creep at low aid at high temperatures were derived. The activation energy at low temperatures is the same as that for jog formation and the activation energy at high temperatures agrees with that for climb. COTTRELL has suggested that at low temperatures, the expansion of dislocation loops under stresses near the yield strength is limited by the rate at____ which the expanding loops can cut the "forest" of dislocations passing through the glide planes.&apos; On the basis of this mechanism, seeger2 has derived expressions for low-temperature creep and for the relation of flow stress of single crystals to temperature. In the work reported here, the authors have performed experiments designed to obtain quantitative data on the physical properties of the dislocation intersection mechanisms operating during basal slip in pure magnesium monocrystals. Above a critical temperature, dislocations thread-

Jan 1, 1961

By J. A. Holmes

It is a fact that is coming to be more widely recognized by the general public, as well as by members of the medical fraternity, that the health of persons living in our hill-country depends in no small degree upon the drinking water obtained, just as it has been found that the* use of pure water in the lowlands and swamp-areas of the Southern States results in practical immunity from malarial diseases. Hence the problem, how to obtain supplies of wholesome water for the towns and manufacturing establishments in the hill-country or Piedmont plateau-region of the Southeastern States, becomes one of considerable interest, the importance of which will continue to increase, as the favorable conditions for manufactures and agriculture in this region will make it, in the near future, the most thickly populated portion of the South Atlantic States. Water-supplies from Surface-streams are unquestionably of the first importance; and in the mountain counties, where the region is still largely forest-covered and the streams are swift and continually aerated by rapids and cascades, the water is of superior purity and clearness. This statement is also applicable to the more elevated and sparsely settled portions of the Piedmont plateau; but in the less hilly and more thickly settled portions of this region the streams are more sluggish, and the waters more muddy and less pure, owing to the fact that a much larger proportion of the surface is under cultivation.

Jan 1, 1896

By M. F. Williams, L. G. Hendrickson

In classification of pulps bearing magnetized ferro-magnetic particles, depolarizing is of great importance. If size separation is to be effective, particles must be individual rather than in flocs. Depolarizing is also practiced in heavy medium separations in which ferrosilicon or magnetite is the medium. When particles of ferromagnetic material have been removed from a magnetic field, residual magnetism causes agglomeration. The term depolarizing refers to the operation of reducing or eliminating this residual magnetism and may thus be considered magnetic deflocculation. The terms demagnetizing and randomizing are also used.

Feb 1, 1956

By Gary J. Brown

AMAX Coal Company, the nation&apos;s third largest coal producer operating in Indiana, Illinois and Wyoming, is a division of AMAX, INC., a United States based natural resources corporation that operates world wide. The operations in Wyoming (The Western Division) include Belle Ayr and Eagle Butte Mines. Belle Ayr Mine, located 18 miles south of Gillette, Wyoming, presently employs 440 people. It was started into production in 1973 and has been the largest producing coal mine in the United States since 1977. Final figures will show that the mine was again the largest in 1980 with production levels of approximately 16.1 million tons, total production of coal in the United States being in excess of 800 million tons during this last year. As one of the first commercial producers of sub-bituminous coal in the Powder River Basin, Belle Ayr has served as an example for the many other mines which have since been constructed in that region. The four coal storage silos are the first and most dominant features of the mine to be seen for miles across the Wyoming prairie. Each silo has the capacity to load a 110-car unit train in excess of 11,000 tons. All service facilities at the mine are under one roof. Included in the service building are off ices, warehousing, seven garage bays, and washhouse facilities for all employees. Preparation of coal for shipping at Belle Ayr consists only of crushing from pit-run size to 2 x 0-in. Primary crushing is done under the truck hoppers to 6-8-in. product size. Secondary crushing is performed in the two large crusher buildings. The smallest plant can produce at the rate of 2,500 tph, while the larger can produce

Jan 1, 1983

By H. P. Reid

PORTLAND cement is manufactured under either of two general proc-esses, the wet or the dry. The raw materials in general consist of limestone, shells, marl, cement rock, clay, shale, blast-furnace slag, etc., so proportioned that when calcined the desired composition will be obtained. In the wet process the combined raw materials are ground to extreme fineness in the presence of water, to a resulting slurry of from 30 to 50 per cent moisture content. The moisture of the slurry may be reduced by thickening or filtering processes for feed to the cement kiln or the slurry may be fed to the kiln with its full percentage of water. The dry process differs from the wet in that the surface moisture of the raw materials is removed prior to grinding. For the drying of these materials heat is required and in most cases is produced by burning of raw fuel either on grates or stokers before the dryers or in suspension in the form of pulverized coal, oil or gaseous fuel. The power required for making the cement is sometimes purchased from outside sources; sometimes it is generated from the heat in the waste gases leaving the cement kilns, or generated at the plants direct from raw fuel. We have, then, as the possible requirements of fuel in the cement industry: (1) fuel for power generation, (2) fuel for drying raw materials, including coal before pulverizing, and (3) fuel for burning the raw materials to cement clinker. There is no essential difference in quality required in fuel for burning the materials by the wet and dry processes.

Jan 1, 1932

By David White

THE submission of carefully prepared estimates of the oil reserves of the United States calls for no apology or explanation. In this country, petroleum is a rapidly wasting asset and an occasional appraisal of the amount remaining in the ground is a simple business procedure to safe-guard the general welfare and the prosperity of the republic. The rumored danger of failure, in the near future, of the foreign supply on which we depend in constantly increasing amounts makes the immediate review of our available reserves the more imperative. The Director of the U. S. Geological Survey, in March, 1921, requested the American Association of Petroleum Geologists to cooperate in the preparation of new estimates of the oil remaining in the ground. With the members of this cooperative committee, state geologists, regional geologists, consulting specialists, and geologists and engineers attached to many companies worked both independently and through sub-committees. The reports for districts, counties, fields, etc., after review by local or state committees, were discussed by the joint cooperative committee in conferences that, in some instances, were attended by the original compilers of estimates for the states or smaller areas. Finally the data were reviewed and the figures revised by the joint cooperative committee, so that the totals given in Table 1 represent the opinion of the committee, which was composed of F. W. DeWolf, W. E. Wrather, Roswell H. Johnson, Wallace A. Pratt, Alexander W. McCoy, Carl H. Beal, C. T. Lupton, G. C. Matson, K. C. Heald, W. T. Thom, Jr., A. E. Fath, Kirtley F. Mather, R. C. Moore, and David White, chairman.

Jan 6, 1922

By M. R. Geer, H. F. Yancey, P. S. Jacobsen

Two growing problems confront the preparation engineer-still further restrictions on stream pollution and a greater proportion of fine coal as more and more continuous miners come into use. The dewatering screens, centrifuges, and settling ponds that sufficed a few years ago must often be supplemented by more effective equipment, and in some instances the finest solids are now being recovered by vacuum filtration, once considered too costly in many coal washeries. Unfortunately not all slurries can be readily filtered. Some are virtually unfilterable, and others do not permit the high cake rates needed to hold costs within reason. Often, however, these difficult slurries can be rendered filterable by flocculation. Starch and lime have long increased settling rate in thickeners and can also aid filtration. More recently there have been other flocculants, primarily synthetic polymers or gums. Reports of their great effectiveness prompted the U. S. Bureau of Mines to test their use in filtration as part of its program on recovering and cleaning fine coal. The object of the present work was to compare some of the newer flocculants with starch and lime and to test the reaction of different types of slurries to flocculation. Three natural slurries, three synthetic coal-clay mixtures, and five flocculants were tested, all with a laboratory filter leaf.

Jan 7, 1959