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By E. R. Hendrickson

About 1/3 of the world's supply of phosphate rock is produced in a relatively small area of the Florida peninsula east of Tampa. Until this past year, a circle with a radius of about 25 miles and centered on Bartow would encompass the major producing areas. During the past year producing areas have opened in North Florida which promise to vie with the Polk-Hillsborough County area in terms of proven reserves. In addition, new phosphate production is planned for counties to the south and west of the present fields. From the existing production areas, however, more than 19 million long tons of phosphate were mined in 1965. As mining engineers most of you probably are familiar with the methods of mining and beneficiating the pebble phosphate rock. You thus recognize that, although some water quality problems may arise from these processes, there is no potential air pollution problem. To make an economically useful product, however, further processing must take place. It is from this additional processing that potentially damaging materials may be discharged to the atmosphere.

Jan 1, 1966

By P. E. Weidmark

"PART I - Published PapersBallivy, G., and Dupuis, M., ""Laboratory testing for the design of grouted rock anchors""; Proc 6th Pan Am Conf Soil Mech Found Eng; Lima; 1:277-291; 1979.Ballivy, G., Ladanyi, B., and Gill, D., ""The effects of moisture content on the strength of fissured rocks""; Proc 1// 1ntnl Congr 1.A.E.G.; Madrid; //:2:7-16; 1978.Baumgartner, P., and Stimpson, B., ""Development of a tiltable base friction frame for kinematic studies of caving at various depths""; Int J Rock Mech Min Sci Geomech Abstr; 16:4:265-267; 1979.Bawden, W.F., and Roegiers, J.-c., ""Discussion and interpretation of the mathematics governing radial flow in a single horizontal rock fracture""; ISBN 07727-7002-6; Dept Civil Engng publication 79-11; Univ Toronto: 134p;1979.Chatterji, P.K., Smith, L.B., and Insley, A.E., ""Construction of Saline Creek Tunnel in Athabasca oil sand""; Can Geotech J; 16:1:90-107: 1979.Coates, D.F., and Gyenge, M., ""A case history of pit slope design""; Proc 4th ISRM Congr; Montreux, Switzerland; Sept 1979; 1:Theme IV:591-596; 1979.Crawford, A.M., and Curran, J.H., ""A dynamic direct shear machine for determining the time-dependent behaviour of rock joints"": Dept Civil Engng publication 79-08; Univ Toronto; 1979.Crawford, A.M., and Curran, J.H., ""A displacement discontinuity approach to modelling the creep behavior of rock and its discontinuities""; Dept Civil Engng publication 79-09; Univ Toronto; 1979.Crawford, A.M., and Curran, J.H., ""A higher-order displacement discontinuity element""; Dept Civil Engng publication 79-10; Univ Toronto; 1979.Cruden, D.M., ""A computer-based system for rock mass description""; Proc 1// Intnl Congr I.A.E.G.; Madrid; //:2:155-159; 1978.Cruikshank, D.J., and Curran, J.H., ""A.B.LE. approach to modelling of fluid flow in fractured rock masses""; Proc 7th Cdn Congr Appl Mech; May 1979; Sherbrooke, Que; 887-888; 1979."

Jan 1, 1980

By C. Hays, R. E. Swift, E. G. Kendall

Investigations of the Zr-Pt system, by metallography, incipient melting, and X-ray diffraction, determined the phase relationshifis from 0 to 50 at. pct Pt. Phase fields in the Pt-~ich region were outlined, and three intermetallics (ZrPt, Zr2Pt, and ZrPtd were located. A eutectic between Zr and Zr2Pt, and a eutectoid veaction between Zr and a Zr + Zr2Pt, were established. The maximum solubility of Pt in P Zr was approximately 13.5 wt pct, as opposed to less than 1 wt pct solubility in a Zr. EARLIER work on the Zr-Pt system was limited to an X-ray study on the intermetallic compound, ZrPt3, by H. J. Wallbaum,1 It was reported that ZrPt3 existed at 86.52 wt pct Pt, and had a hexagonal structure, isomorphous with TiNi3. Wallbaum's data revealed the following structural particulars: a = 5.633A, c = 9.21A, and c/a = 1.635A. Other studies allied to Zr-Pt alloys concerned only 1) Pt-rich alloys (0.05 to 5.0 pct Zr) for corrosion resistance,2 2) a Zr-base alloy with 5 pct Pt and 0.124 pct C for oxidation resistance,3 and 3) electroclad-ding of Zr with Pt for in-pile corrosion resistance of Zr to uranyl sulphate. 4 Metallographic, incipient melting, and X-ray diffraction techniques were applied to accurately resolve the phase relationships in the 0 to 50 at. pct (68.2 wt pct) Pt region, and to outline the phase fields in the Pt-rich area. Three intermediate phases: Zr2Pt, ZrPt, and ZrPt3, were also established by the same methods. PROCEDURE Melting stock for this program was of the highest purity obtainable. The Zr was iodide crystal bar with a low hafnium content of about 0.05 wt pct (Westinghouse "Grade 3"). The as-received Zr was treated to remove the surface film of corrosion product that resulted from a standard autoclave grade designation test. Next, the bars were processed to yield material suitable for arc melting and free of contaminants. Sheet platinum metal (Baker and Co. "Grade 2") was used for alloying additions. This material con-

Jan 1, 1962

By J. W. MacDonald

PROPERTY AND PRODUCTION: Around 100 Million Tons of Recoverable Coal are available from the approximate 10,000 acres allocated to the mine. Over 1300 acres of surface land holdings extend well beyond the limits required for plant site, storage tracks, water supply reservoir, settling ponds and waste disposal. COAL: Extensive core drilled testing confirmed the early indicated high quality of the #6 Seam Washability data show less than four percent of the' coal seam required removal to provide a superior product for the available market. PREPARATION PANT DESIGN: The limited needs enabled Preparation Plant Design to meet the requirements without inclusion of novel equipment. The simplified needs afforded ample opportunity for considering increased automation where advantage or economy was antioipated. Plant design included protection of opportunity for pre-drying in advance of air cleaning the fine coal and accommodations for addition of Dense Media separating equipment in event warranted or required by future market changes. Protection is also afforded for addition of Raw Coal Storage accommodations in event warranted. Figure I shows the Preparation Plant Flow Sheet.

Jan 1, 1961

By R. L. Dietrich

[ ] We at The Dow Chemical Co. have recently done some work on the deformation of magnesium alloys and although it is far from complete there have been a few observations which may be of interest in connection with this paper. In the first place, I should like to point out that the deformation of polycrystalline magnesium alloys has not been completely explained by the work on single crystals. Bakarian and Mathewson found slip on the ( 101) and {002) planes, and (102) twinning as the deformation mechanisms in magnesium single crystals, but in compression when the (002} planes were within ii° of parallel t0 the compression surfaces, fracture occurred at all temperatures up to 340°C (644°F). In commercial working processes, particularly in rolling, an orientation is quickly produced which should be unfavorable to further deformation by the three established mechanisms. The first few reductions in rolling quickly produce an orientation having

Jan 1, 1947

By E. Kurt

The field of percussion rock drilling is subdivided into two areas of application; that which takes place on the surface and that which takes place underground. Surface drills are used in quarrying, highway construction, and maintenance work; underground equipment in mining and tunneling work. Two basic principles are involved in the operation of all percussion drills. First, the principle that reciprocates the impacting piston and second, the principle that causes the drill steel and bit to rotate. The back and forth motion of the piston is accomplished by a self-acting automatic valve that admits air alternately to each end of the piston (Figure 1). Drill steel and bit rotation is imparted by an integral ratchet mechanism (Figure 2) in the so-called "rifle bar" machines (Figure 1) or by a separate pneumatic motor in "independent rotation" drills (Figure 3). While rock drills are subject to all kinds of physical and operational abuse, they are most sensitive to faulty lubrication. Proper lubrication is the single most important factor in the longevity of a percussion drill.

Jan 1, 1970

By M. G. F. Söhnlein

In a Bolivian tin concentrator an appliance was needed to furnish a suitable product for fine jigging from a pulp of the following composition: Mesh Per Cent. + 20 8.0 40 36.5 + 60 9.0 + 80 10.5 + loo 5.5 4-150 1 4.5 -150 25.0 99.0 Loss 1.0 In the jigging process, particles of cassiterite as small as 0.1 mm. can be recovered, provided they are not present in excess, that is if the material treated on the jigs contains sufficient coarser sands to keep the interstices between the grains open. Removing the fine material from the pulp by screening, to prepare the jig feed, is impractical, because that means the use of an 80-mesh screen or finer, and is not as effective as hydraulic classification. A screen would eliminate mineral grains from the feed which can be recovered by jigging, and in addition would throw more gangue and low-grade middling on to the jig. Formerly a one-spigot Richards vortex classifier had been used to accomplish this separation, but the tangential openings through which the hydraulic water enters became clogged by fine vegetal matter with which the water was contaminated, and which it was impossible to remove from the water. Consequently the work of the classifier was imperfect and a good deal of slime was sent to the jig. When designing the plant referred to in this paper it was decided to use a hydraulic classifier as shown in Fig. 1. The essential features had been copied from the Anaconda classifier.' This remodeled classifier consists of a truncated pyramidal wooden hopper A with an attachment of cast iron

Jan 1, 1917

By Shosei Serata

Salt cavities have been proven to be a suitable structure for underground storage of various matters in gas, liquid or solid form. Since the technique of underground storage was developed mainly through field experiences in solution mining, a wider use of solution cavities for storage of gaseous and solid matters requires evaluation of three basic rock mechanics problems; cavity instability, boundary rock failure and surface subsidence. Cavity instability is due to the non-linear long-term creep properties of the surrounding ground media which are sensitive to cavity pressure changes associated with the storage. The cavity boundary rock failure is caused by the loss of effective confining pressure to the boundary rock media in the process of storage of gaseous and solid matters. Surface subsidence is the final outcome of the stress envelope originated around a cavity, eventually reaching the ground surface. The rock mechanics processes of instability, failure and surface subsidence are explained by using various field examples in salt domes and bedded formations. Methods of solving the problems are discussed including stress relief, stress control and computer optimization of design.

Jan 1, 1973

By William H. White

"AbstractThe value of anomalous metal contents of trees as an aid to the discovery of mineral deposits was tested under field conditions cm four known ore deposits. Results indicate that a base-metal deposit, or any deposit containing zinc or copper, casts a 'metal shadow' into the overlying soil which remains approximately positioned above the deposit, regardless of the type of overburden or the movement of groundwater.The unusually high content of zinc or copper in trees growing within the limits of this 'metal shadow' constitutes an anomaly which can be detected and ,plotted in the field The field kit and certain points of the field technique are described briefly; and the characteristics of plant anomalies and possible limitations of their use are mentioned.IntroductionRecent investigations concerning the metal content of trees indicate not only wide variations in the metal content of different species and in different parts of the same tree but, in addition, suggest that the metal content of a tree is related to that of the subjacent bed-rock. Abnormal values found by Warren, Delavault, and others in trees growing above or near orebodies suggest a new tool which may prove of considerable value in exploration work. Evaluation of this new tool must involve consideration of the following questions:(I) Is the technique one which can be used under field conditions by persons not specially trained; and can results be duplicated within reasonable limits of error? Rather than taking tree samples for subsequent laboratory analysis, it is highly desirable that analyses be made on the spot. This allows anomalous results to be checked and additional samples may be taken at key points."

Jan 1, 1950

By Jerry W. Stengel

The Bureau of Mines subjected two manufacturers' chemical oxygen (K02) self-rescue breathing apparatus to a series of laboratory environmental treatments designed to simulate various conditions in underground coal mines. The environmental treatments consisted of extremes of temperature, shock, and vibration. The tests were designed to be used as predictors of the ability of the self-rescuers to survive those environmental insults with no degradation in their protection to the wearer. Based on the severity of the treatments, simulating conditions more severe than offered by the mining environment, the two apparatus tested should be able to withstand the abuse offered by the mining environment and still function as intended in an emergency. Correlation of these tests with results of long-term field evaluations is needed to provide confidence in the laboratory tests as predictors.

Jan 1, 1982

By R. L. Bruening, N. E. Izatt, S. R. Izatt

The need for selective metal separations has increased as the mining industry encounters more complex ore bodies and demand for higher performance end products expands. The Molecular Recognition Technology (MRT) process uses highly selective SuperLig® resins to remove desired metals from a variety of solutions in the mining and metals processing and recovery industries. MRT separation processes efficiently produce high purity metal products. In this paper, applications of MRT to metal recovery at mg/L to multiple g/L concentration levels are presented and discussed. Specific examples in the precious metal, nickel, cobalt, zinc, copper, and rare earth industries are given.

Jan 1, 2014

By Kelly C. Strebig

Laboratory tests were conducted by the Bureau of Mines to determine the effect of depth of cut and bit type on respirable coal dust generation. Apparatuses were constructed to contain the coal samples, measure the linear cutting forces, and analyze the dust generated. Single-bit tests were conducted in Illinois No. 5 and Pittsburgh seam coals with five bit types at four depths of cut. The results showed that bit type did not significantly influence dust production. On the other hand, deep-cutting bits were more efficient and generated substantially less respirable dust per pound of coal broke than shallow-cutting bits.

Jan 1, 1975

By P. Patnaik, F. Cuneo, D. M. Wang

Microwave (MW) energy has been used widely for several decades for communications, food processing, wood drying, vulcanization of rubber and medical therapy. Recently, this technology was found to be capable of successfully sintering ceramic and metallic powder materials, with the advantages of reducing soaking times and sintering temperatures. Unlike conventional heating, MW radiation works through the absorption of the microwave energy by a material placed in an electromagnetic field within the microwave cavity. A far more efficient heating process is produced due to the unique ability of microwaves in selectively heating a pecific part of the material with desirable dielectrical properties. This exploratory research was initiated with the objective of locally sintering the thermal barrier coating of gas turbine components using MW radiation. This novel technique may allow repairing of the component without subjecting the entire piece to unnecessary elevated temperatures and reduction of process time and cost. Y ttria stabilized zirconia was used in this study and sintering was conducted using a multimodal 1.2 kW microwave facility. Three configurations of heating setup were experimented and the preliminary results will be discussed in this paper.

Jan 1, 2006

By Dale K. Nash

The authors have developed a com¬puter-assisted critical path planning and scheduling model to help reduce time required to move longwall mining units. The model includes time constraints and limited resource constraints, such as manpower, machinery, supplies, work space, and transportation routes. Outstanding results were achieved on the first move to which the computer-model pas applied; e.g., downtime due to the move was cut by 50%. The model and the schedules developed using it provide an excellent blueprint for future moves and have led to significant savings in time and costs for Emery Mining Corporation, Huntington, Utah.

Jan 1, 1983

By Donald C. Barton

The elastic earth waves produced naturally by earthquakes have been used for a long time as evidence from which to draw conclusions in ; regard to the constitution of the interior and crust of the earth. The I elastic earth waves produced artificially by occasional explosions and ' recorded by seismological observatories were used to draw conclusions regarding the geology of the intervening area. Intentionally produced elastic earth waves in the past five years have come to be used extensively in the investigation of very local geologic structure. The scismic method of working geologic structure, which makes use of artificially controlled explosions and the resulting earth waves, has developed almost clairvoyant power in handling certain geologic situations; and, in the discovery of salt domes in the Gulf Coastal Plain region of Texas and Louisiana, it has scored the most brilliant success. The first proposal for the use of artificial earthquakes in the study of velocity of elastic earth waves in the surface formations of the earth's crust were made before 1888, by the English seismologists mallet and Abbot. Partly on the basis of their work, A. Schmidt in 1888 proposed the use of time-(Iistnncc graphs of artificial earthquakes to study the variation of vellocity with depth. Belar in 1902 proposed the practical 'application of such investigation in connection with boring tunnels. Galitzcn repeated1y (1912. I9IX) proposed the use of explosions to study the velocity of the longitudinal and transverse waves in the uppermost formations and pointed out that the velocity depended in a high degree on the physical character of the beds and that from changes in the velocity, conclusions could be drawn in regard to the composition of the beds. Somewhat the same thought was proposed by von dem Borne (1908), by Benndorf, Udden and others.' First Use of Artificially Excited Earth waves to Determine Local structure The first application of the use of artificially excited elastic earth waves to thc determination of local geologic structure was worked out,

Jan 1, 1929

By W. M. Ma, W. L. Zhong, Syd S. Peng

In a longwall section that consisted of 7 longwall panels, there were two high pressure gas transmission pipelines across the panels burying from 3 to 10 ft. below the surface. One pipeline was 20 in. in diameter while the other was 24 in. in diameter. In order to investigate the stress conditions sustained by the pipelines during underground longwall mining, strain gages were mounted on the pipelines above panel #3, #4, and #5. Survey monuments were also installed along but near the pipelines. This paper presents a subsidence prediction method and the preliminary results of the pipelines' stress conditions as affected by underground longwall mining.

Jan 1, 1986

By Mark William Kennedy

"Electric furnaces containing high quantities of slag are applied in many areas of pyrometallurgy, often for smelting or slag cleaning. A variety of ratios or rules of thumb have been employed in the industry for the dimensioning of these vessels, in most cases with no clear technical basis.In this paper, several design guidelines are presented (electrode size, spacing, vessel dimensions, energy intensity, etc.) as an attempt to provide some technical basis for optimal dimensioning.Furnace heat generation is related to side wall copper cooler heat losses, in an attempt to establish a methodical design strategy particularly for minimum electrode to wall spacing for modern furnaces with cooled linings.Issues regarding the true nature of heat production in a slag furnace are discussed with regards to the possible impact on accurate modeling and design.IntroductionSlag furnaces have passed through a number of design 'generations' characterized by increasing energy intensities, improved electrode technologies and advancing development in their physical structure or 'furnace integrity' as shown in Table I f 1]. A 3rd generation furnace using ultra-high-power (UHP) graphite electrodes is shown in Figure 1, as a generic example of the types of physical structures present in modern slag furnace designs [1]."

Jan 1, 2012

By William Crane

OPERATORS of diamond drills have long been familiar with thread-like markings or riflings on cores but apparently have given but little serious thought to the conditions that are responsible for their production. The opinion generally held by those who have observed the phenomena is that the riflings are produced directly or indirectly by vibration, but so far as the writer is aware no systematic attempt has been made to demonstrate the fact. A careful search through the literature on diamond-drilling practice has been rewarded by only one reference to such markings of cores. J. N. Justice1 writes, "Of the peculiarities met with in the core, I will mention only one. The core from the "H" drill, at about 360 ft. came out rifled and pentagonal. The change from the circular to the pentagonal was sudden, and for 9 ft. this structure was maintained, when suddenly it returned to the circular. I have not been able to find any one who can explain the cause of this change of form. The drill men marveled at it and suggested vibration, six-stone bits, and several other hypotheses Which need not be mentioned." The writer became interested in the matter of core riflings some 10 years ago while in the Flat River lead region of Missouri, where many remarkable examples of "rifled" cores were observed and collected. Since that time similar phenomena have been observed in various localities throughout the United States and Canada, and samples have been gotten together illustrating a large number of variations in form. After a careful study had been made of the material at hand it seemed desirable that certain data should be obtained from the experience of others regarding the normal action of diamond drills in forming cores, portions of which are occasionally rifled, before an attempt was made to draw any conclusions as to their cause.

Jan 5, 1916

The writer presents a concise summary of eleven recent discoveries made in the Maritime Appalachian area, with suggestions for fur the research. This information may prove helpful to geologists working in other fields and to students contemplating further avenues of research in mining geology and exploration. INTRODUCTION THIS paper is not intended as a research study on the subject, but i. merely a brief review of eleven discoveries that have been made in the Canadian Appalachian area. Furthermore, this is not a critical analysis of the merits of any one geophysical method, but it is an un-prejudiced observation of how these discoveries were actually made and what techniques were apparently most fruitful. Some generalizations are attempted whicl1 may suggest further avenues of research in the field of mining exploration. The writer wishes to thank his colleagues in the field for their comments, which he was able to in-corporate into this paper. In particular, he is grateful to Dr. Paul Bevan and

Jan 1, 1963

By M. D. Flavel

Testing methods are described to help in decisions of selecting the most viable comminution circuits. The authors present a comparison evaluation based on numerous studies to help make initial choices for feasibility evaluations. An update summary of completed Bond grindability and Abrasion Index testwork at Allis-Chalmers Process Research Test Center for all materials is included. "What is the best circuit to comminute primary crusher product to make beneficiation feed?" This frequently asked question has the implication that there is one circuit which is universally the right circuit. The answer has been sought ever since it has been necessary to break rock to liberate entrapped mineral values. With every new contribution to the art and the science of comminution, the scope of the discussions broaden. It is not even possible to define what the abstract term best means.

Jan 1, 1981