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By H. S. Martin

The Phosphate Recovery Corporation operates three flotation plants, Nos. 1 and 2 concentrators about three miles northeast of Mulberry, Florida, and No. 3 plant at Wales, Tennessee. These plants represent the first commercial phosphate flotation operation and are also believed to be the largest nonmetallic flotation operation in the world at the present time. The details of this paper will be confined to plant No. 2, this being the newest and largest concentrator in Florida, and the flow sheet being practically the same as at plant No. 1. The No. 3 plant has been operated but a short time and has been shut down since December, 1932, on account of the decrease in phosphate rock production. The phosphate washers usually are located centrally on a known deposit so that about two hundred acres of ground can be mined economically to each washer location. The washers are moved to new areas when the distance becomes too great for economical pumping. The flotation plants are built either adjacent to a washer, so that current debris may be utilized, or on the site of a former washer where there is sufficient accumulated debris available for mining, and the flotation plants must also be moved from time to time. Most of the water used in the Florida flotation plants is recovered after passing through a circulating system where most of the fine suspended matter is settled out, but some make-up water is obtained from deep wells near the plant. Power is obtained from the Tampa Electric Co. through the distribution facilities of the International Agricultural Corporation. Flotation concentrate is hauled from the plant by trolley over the International Agricultural Corporation's trolley system, to the drying plant at Prairie, one mile northwest of Mulberry. Ore Treated In the pebble phosphate district of Florida, the phosphate mineral, or collophane, is usually found in horizontal beds of varying thickness

Jan 1, 1935

Underground Mine Drainage may be conveniently divided into two operations:(a) Collecting and transporting drainage water to the pump eastern.(b) Elevating water to the surfacc by pumping.This short paper describes a system which automatically performs operation "a" and which has been developed on the South mine at Broken Hill, under the supervision of the mine foreman, Mr. F. McDonell. Operation "a" does not come under the heading of "subsidiary mine" drainage.SUMMARY(1) All drainage waters are collected by gravity flow into sumps.(2) Automatic control boxes operate syphons which transfer water from level to level to pump cisterns or to feed water service.EQUIPMENTSyphon Control Boar - Constructed of 10 ft. x 2 ft. oregon timber, suitably bolted together and equipped with a Bailey's cistern valve, with copper ball float control, and 12 in. pipcs and fittings forming a syphon (Fig. 1). One of these boxes is placed on each level at the shaft.The valve and float are so arranged that when the float is up (ie, box full) the valve will be fully open, and when the float is down (ie, box empty) the valve is closed. The vertical range between the cxtreme positions can be altercd by lengthening orshortening the adjustable arm of the float. The ideal valve is one...

Jan 1, 1927

By J. M. Pei

In this paper, the nonlinear finite element analysis is used to study the support system of a tunnel which is designed to pass through deep-embeded stratum. The rock mass is rather intact, though a section of tunnel will pass through the weak belt. Under the influence of the high ground stress, the condition of stability and the form of support become complicate. This paper, talcing into account the nonlinear properties of rock mass and the Interaction between rock, and support, makes a comparison between the two kinds of soft and rigid support systems, and analysed the changes of their bearing forces.

Jan 1, 2010

By R. D. Lindsay

Pamour Porcupine Mines, Limited has been actively engaged in the ''Custom Tolling'' of Gold-Bearing materials throughout the past decade. Experience acquired in this area was utilized to design and commission a custom gold milling facility at its operations in Timmins, capable of:(a) Accepting a bulk ore test sample at the rate of 150 t/d for crushing, sampling, and metals analysis;(b) Processing gold-bearing ores at a rated capacity of 150 t/d, to produce a goldbearing sulphide concentrate;(c) Processing free milling gold ores at a rated capacity of 80 t/d for total cyanidation;(d) Cyaniding custom gold flotation concentrates at a rated capacity of 80 t/d; and(e) Processing of complex gold/copper or carbonaceous ores, requiring an impurity flotation concentrate separation stage prior to cyanidation, at a rated capacity of 100 t/d.Items considered in the process design and development included:- various gold ore types available for processing;- flowsheet flexibility required;- sampling strategy as related to head grade determination and metals accounting; and- contract considerations.This paper highlights how these various considerations were used to design Pamour's ''Custom Gold Milling Facility''.

Jan 1, 1987

By Gregory M. Molinda

Historically, miners have known that roof rocks originally composed largely of mud were prone to slaking and deterioration when exposed to water and humidity. Mine Safety and Health Administration (MSHA) records show that roof falls are more prevalent in summer and late fall. Field data shows higher bolt loads and increased room convergence in summer months. Laboratory data shows that very high internal pressures can be generated by significant strain in clay-rich rocks. In summer months humidities ranging from 70-100% can cause rock strains up to 7%, and rock pressures of 14,000 psi, more than enough to break apart weak shales and fireclays. The National Institute for Occupational Safety and Health (NIOSH) conducted wet/dry immersion cycling of clay-rich rocks. Results show that the rocks most prone to moisture deterioration are fireclays, claystones, and sandy shales, all of which have disrupted bedding. Of the 7 mudrocks with a weatherability index above 40%, none showed consistent fissile bedding. Black shales were surprisingly resistant to wet/dry water immersion cycling. Generally, mixed rocks (stackrock), typically susceptible to horizontal stress, are more resistant to moisture-deterioration. Mine roof rocks tested with moisture sensitivity ratings above 50% (moisture sensitivity index ranges from 0-100 with 100 being the most sensitive) all came from mines which had roof skin problems and used supplemental support to prevent rock fall injuries. Some roof rocks showed lateral variability of moisture sensitivity values, suggesting the need for more samples in highly varying roof rocks. Swelling strains of mudrocks showed that almost all of the swelling occurred in the first 24 hours after immersion. The wet/dry immersion cycling test used provides an accurate, quick and inexpensive method for estimating the moisture sensitivity of mudrocks. With this information mine operators can begin to anticipate hazardous ground and prepare appropriate roof support.

Jan 1, 2006

By B. H. Caudle, L. G. Loncarie

Pilot flooding is one method of evaluating a proposed secondary recovery project. However, the amount and rate of oil recovery from an unconfined pilot area is not usually the same as from an equal area in a large-scale flood. This is true because fluids are free to move across the boundary of a pilot area. The result is that some of the oil produced in a pilot flood may come from outside the designated area and some of the displaced oil may leave the pilot area completely. This paper presents the results of fluid-flow model studies on a five-spot pilot flood. Mobility ratios between 0.1 and to have been studied. The effects of changing the ratio of injection to withdrawal rates are shown. INTRODUCTION A small-scale field test, or pilot flood, is an accepted method for evaluating the applicability of a secondary recovery operation and the economic potential of that operation for a reservoir. The pilot flood is carried on in the same manner, with the same injected materials and at the same pressures as would be used were the secondary recovery program to be expanded to a larger area of the field or to the entire field. If the reservoir fluid and reservoir rock properties are the same in the pilot area as in the rest of the reservoir, the production, injection and other pertinent data associated with the pilot test will represent and measure what should be expected from a full-scale development of this secondary recovery program. There is one major exception which, unfortunately, has been overlooked by many and which has been awaiting quantitative definition. This is the sweep-out pattern the reservoir engineer must use in interpreting the pilot flood and in extrapolating it to the full-scale development. The sweep-out area in a pilot flood is not contained within the five-spot pattern. Further, there is oil flow into and/or out of the five-spot during a pilot test. Thus, production data from pilots must be interpreted with this different flow system and sweep pattern in mind. We have studied the sweep-out pattern that will exist for some conditions of operation of pilot flooding a single five-spot (four injection wells and one producer). In our study, reported here, we have assumed that the reservoir is relatively homogeneous and of uniform thickness in the pilot area. The results of this study en-able the engineer to predict the recovery, injection requirements and project life for a full-scale operation from the pilot flooding data. The effects of various injection to withdrawal-rate ratios and mobility ratios in a relatively gas-free (10 per cent pore volume or less) system are shown. Experimental Method The technique used in this study was the same as that for the X-ray shadowgraph studies of sweep-out pattern efficiencies.' The model of the pilot and surrounding area was made from a uniform packing of round-grain sand consolidated with an epoxy resin. Fig. 1 shows the relation between the model and the pilot area. Only one-eighth of the pilot area had to be represented in the model because we assumed equal injec-

By L. P. James, W. W. Atkinson

Utah has produced about one billion troy oz. (31.7M tonnes) of silver, more than any U.S. state except Idaho. Several very high grade ore systems, now closed, occur within large polymetallic limestone-hosted districts related to plutonic complexes. These Utah mines fed several major lead smelters for nearly a century. Interaction of magmatic chloride-rich fluids with carbonate rocks localized significant bonanzas within these districts. A low sulfidation state was produced in the fluids by their passage through limestones. The Bingham porphyry mine has also yielded more byproduct silver than other porphyry copper-gold systems. Away from exposed intrusive rocks, some large silver-only systems occur in Mesozoic sandstone and in caldera-related veins in volcano sedimentary rocks. Thick permeable latest-Proterozoic basement meta quartzite sequences present beneath western Utah may have been important, as perhaps they were in the Coeur d’Alene district of Idaho, in providing chloride and silver-rich ore fluids. However, it is clear that specific Tertiary magmatic events played an essential role in the evolution of the Utah silver-rich metallogenic province. The largest silver districts in the state are genetically related to porphyritic plutonic rocks.

Jan 1, 2000

By K. Meyer

"The largest cost centres of the David Bell Mine concentrator are grinding, leaching and effluent treatment. Optimizing results during the 6th year of operation are listed below: o SAG mill slurry density control and operating strategies improved liner life and media consumption by 10 and 25%, respectively.o Poly-met liners clad the SAG mill except for the feed end. Lower noise levels and reduced mill downtime have resulted in an improved and more efficient workplace (time required for liner changes is 2 to 3%).o A comparative grinding media study using seven different marked media at the same time showed media wear rates range 120 to 198 mg/kWh and ball mill charge replacement frequencies of 8.3 to 13.1 per year, and that a meaningful wear test must include all media to be tested at the same time in the same mill. High quality carbon steel cylinders had the best economics.o Pre-aeration, using pure gaseous oxygen is accomplished in pipe reactors. Small bubble generators provide oxygen in the first three leach tanks. 1500 to 3000 kg of oxygen is consumed per day. Leach kinetics have improved and trends indicate increases in gold recovery of three to seven ounces per day at reduced costs. Effects of reduced cyanidation of accessory metals on the effluent treatment plant will be discussed in a separate paper."

Jan 1, 1991

By C B. McCampbell, R W. Jr Bickes

Sandia National Laboratories has developed a semiconductor bridge (SCB) igniter for the ignition of a variety of explosive materials. When subjected to a low-energy current pulse, the bridge bursts into a plasma causing rapid ignition of the explosive material pressed against the bridge. Despite the low energies required for ignition, SCB components have proven to be explosively safe, meeting both no-fire and electrostatic discharge (ESD) safety requirements.

Jan 1, 1991

During the drilling campaign conducted between October, 1942; and May, 1943, to prove the extent of the scheelite deposit worked by King Island Scheelite N.L. at Grassy, King Island, Tasmania, 35 holes were drilled and 606 samples recovered and assayed for their content. Of these, 238 came from outside the limits of the orebody and were for the most part barren, although a few contained some scheelite. The present statistical analysis is made only of the 368 samples taken from diamond-drill cores of the orebody itself.Drilling Pattern and Sampling MethodsFrom the purely statistical viewpoint, it is realised that methods employed in selecting sites for diamong.-drilling, and of collecting samples from drill cores, do not give a completely unbiassed set of data for analysis. Fig. 1 is a sketch plan showing the relativepositions of the drillholes, which were inclined at an angle of depression of 50 deg. The pattern does not conform to a properly randomized and' regularly-spaced grid, the positions of the later holes being determined by the results obtained from previous holes.Statistically, the bias is, therefore, favourable. The unequal spacing of the drill holes and the lack of uniformity in direction of the lines along which the holes were drilled are unsatisfactory from the mathematical viewpoint; but it is realised that these irregularitiesare difficult to avoid in determining by the most economical methods the extent of such an orebody, and are dictated by geological rather than mathematical necessity.Sampling, also, is lacking in complete uniformity. Each sample is approximately 10ft. in length. However, owing to the fact that 100% recovery of core is rarely achieved, and actual lengths of samples taken are ,primarily governed by the length of the drill runs,and secondarily by lithological changes, there is a considerable amount of variation in the sample length.AssayingWith the exception of 28 samples from three drill holes all samples dealt with in this paper were assayed in the Melbourne University Ore-Dressing Laboratory of the Commonwealth Scientific and Industrial Research Organisation. These assays were given to the nearest 0.05% WOg as it was considered that more accurate determination was not possible. This fact has been taken into consideration in the frequency analysis below. The 28 assays determined by the Tasmanian Mines Department were given to the nearest 0.01%.

Jan 1, 1950

By R. D. Pehlke, J. V. Gluck

AS a portion of a general study of liquid-metal thermodynamics, high-temperature galvanic cells were used to study the effect of added dilute solutes on the activity of zinc in dilute solution with molten bismuth in the range 450° to 650°C. 1,2 The cells were of the type The experimental procedures have been described previously.1 In the course of studies conducted in the bismuth-rich corner of the systems Bi-Zn-Au and Bi-Zn-Cu, marked discontinuities were observed in the electromotive force-temperature relations for a number of the experimental compositions. Above the discontinuity temperatures, the relations, which were linear, exhibited slopes similar to the binary alloy of the same mole fraction zinc, as shown in Figs. I and 2. Below the discontinuity temperatures, the slopes were markedly different, but the relations remained linear. In general, as the amount of the third eletnent was increased, the slope of the lower portion of the relations tended to become less positive. The slopes of electromotive force-temperature relations reflect the entropy of mixing of zinc and, therefore, the occurrence of a discontinuity marks the transition between two different equilibrium situations involving the solution of zinc. A number of other investigators3-5 have used such observations to determine liquidus boundaries in binary alloys. Since the upper portions of the ternary electromotive force-temperature relations of this study had the same slopes as the binary alloys, the discontinuities are interpreted as marking the transition between the single-phase liquid region and the underlying two- and three-phase regions. Reference to the Zn-Bi equilibrium diagram6 confirms that the binary alloys were single-phase liquids at the experimental temperatures. Fig. I shows the electromotive force-temperature relations for the alloys containing Bi-Zn-Au and Fig. 2 shows similar relations for the Bi-Zn-Cu alloys. In the lower portion of each figure, the temperature of the discontinuity is plotted vs the mole fraction of the added solute at the various levels of zinc concentra- tion. Cross-plots from these curves at constant temperature permitted the construction of the partial liquidus surface isotherms shown in Figs. 3 and 4.

Jan 1, 1967

By BUREAU OF MINES

This report is submitted in accordance with the provisions or une Synthetic Liquid Fuels Act of April 5, 1944 (30 U.S.C. 321-325, as amended), which require that: "The Secretary of the Interior shall render to Congress on or before the first day of January of each year a report on all operations under this Act." Owing to the broad scope of the content and the diversity of interests represented, the Annual Report for 1951 has been divided into two separate publications. Each has been published by the Bureau of Mines as a Report of Investigations, and the respective titles follow: Oil from Coal. R. I. 4865, Part I - R. I. 4866, Part II - Oil from Oil Shale. Identical in each report, the introduction summarizes research progress made in 1951 under the entire Synthetic Liquid Fuels program. A free copy of these publications may be obtained by a written request to the Bureau of Mines, Publications Distribution Section, 4800 Forbes Street, Pittsburgh 13, Pa. The R. I. number and title of the publication desired should be indicated.

Jul 1, 1952

GENERAL CONTRACTOR: ALEXANDER CONSTRUCTORS, INC. STRUCTURAL ENGINEER: CAGLEY & ASSOCIATES, INC. GEOTECHNICAL ENGINEER: F.T. KITLINSKI & ASSOCIATES, INC. PILE FOUNDATION CONTRACTOR: L.G. BARCUS AND SONS, INC. PROJECT PROFILE: 108-10 in. diameter AugerPiles installed to an approximate depth of 32 ft. Piles were installed through Stiff Clayey Fill and Medium-Dense Sands to Decomposed Shale. Piles were drilled to a refusal criteria of 1 ft. / 3 min. Piles were installed using a Barcus Mantis AugerPile rig which is large enough to install piles 25 to 50 ft. long outdoors. The Mantis is also ideal for indoor and low overhead installations. On top of being extremely versatile, the Mantis is also very economical to mobilize. The existing structure is supported on H-Piles. The AugerPiles were furnished and installed for less than the material price of the H-Piles. Design loads were under 40 tons which eliminated the need for a load test. AugerPiles were selected for minimal vibration, limited noise, and economy.

Jan 1, 2001

By R. A. Franks

An evaluation of a nuisance-emissions-discriminating smart mine fire sensor system was made in an operating coal mine. These field evaluations were conducted to determine the sensor system?s ability to discern nuisance emissions, such as diesel exhaust, emissions from flame cutting and welding operations or hydrogen gas from a charging station, from real fires and to compare the number of falsely reported fire alarms generated between the sensor system and a standard carbon monoxide (CO) monitor. The sensor system?s ability to operate successfully in the working environment of an operating coal mine was also evaluated. The smart mine fire sensor system consisted of four sensors whose data outputs were fused with the use of a neural-network-type computer program. Long-term trials were conducted in a haulage way, a belt entry, and a track entry. The system functioned successfully in the belt entry, in accordance with its developmental goals, where the sensor system even discriminated events not anticipated during development. It was not totally effective in the haulage way and track entry, though, due to a combination of significant diurnal air temperature variations, dust, and mechanically induced vibrations. Also, deteriorating rib conditions contributed to operational problems in the haulage way evaluation. In general, the smart mine fire sensor provided nuisance emissions discrimination and was shown to be a viable new approach for mine atmospheric monitoring, enhancing miner safety. This paper describes the in-mine evaluation of the smart mine fire sensor system and discusses recommendations for improving the system. Disclaimer: The findings and conclusions in this report are those of the authors and do not necessarily represent the views of the National Institute for Occupational Safety and Health.

Jan 1, 2008

By Chen Song

Keywords: Co3O4, Cobalt Compounds, Morphology, Urea, Homogeneous Precipitation Depending on experimental condition, precipitation from cobalt nitrate and chloride solution in the presence of urea yield dispersed cobalt compounds with different chemical compositions and morphologies. The effects of concentration of cobalt solution and urea, agitation, on precipitation morphology were investigated experimentally. Generally in closed systems the particles are identified as cobalt (II) basic carbonate with needle type shape. In open system, spherical and plate-like precipitations of cobalt (II) basic cyanate are formed. The chemical formula of cobalt compounds was confirmed. They are CoII,III(OH)0.83(CO3)0.49 Ay?0.14 H2O (in tightly-capped reactor: A stands for NO3?, Cl?; y[A]molecular weight < 12.9) and CoII,III(OH)0.83(NCO)XAy?0.14 H2O. (in open reactor A stands for: NO3?, Cl?; 42 x + y[A]molecular weight < 44.82). The main reason was that the primary particles had different chemical compositions for the effects of the different kinds of anions and stoichio-chemical compositions of the primary particles. The effect degree of the anions depended on the co-existing anion radius in the reaction solution. According DTA-TG analysis of the cobalt compounds, the latter particles transform to Co3O4 powders on calcining. The shape of the Co3O4 particle with porous character has inheritance with precipitation. In this paper, it concludes that the particle formed by the principle of nucleation-aggregation in aqueous solution. The process of aggregation has played an important role in formation of particles. During calcination, the aggregation would be destroyed partly.

Jan 1, 2005

By Andy Davis

The evolution of pit lake water quality depends on the lithology and hydrologic characteristics of the ultimate pit surface, the availability of buffering capacity in the wall rock vs. oxidizable sulfide content, the alkalinity of recharging groundwater and the evapoconcentrative characteristics of the system. This paper assesses the geochemistry of 11 existing pit lakes, ranging from the acid Red Hill and Berkeley pit lakes (pH 2.6 to 2.8) to the alkaline Yerington pit lake (pH 8.45). Predicted pit lake chemistry is similar to that in existing pits, with long-term chemistry lying on a geochemical continuum between end members that consist of influent calcium bicarbonate groundwater and naturally occurring sulfate-rich evaporate playa lakes.

Jan 1, 1997

By Lifeng Zhang

The transport of fluid, heat ,and particles (bubbles and solid inclusions) in flowing molten steel is investigated in steel refining ladles, the continuous casting tundish, continuous casting mold and strand, and steel ingot casting processes. The two-equation k-?? model is used to simulate the turbulence. Multiphase fluid flow is numerically simulated with a Lagrangian-Eulerian approach, an Eularian-Eulerian approach and the Volume Of Fluid (VOF) method. The simulation can predict inclusion trajectories, inclusion removal fraction, free surface waves and other phenomena, which can be used to optimize these important metallurgical operations.

Jan 1, 2006

By J. B. Clemmer

This report summarizes the results of u laboratory study of the beneficiation of Arkansas bauxite by flotation. Although the investigation is not yet completed, a preliminary retort of the results on several typical bauxites is presented to show the merits rind. limitations of flotation for the production of concentrates acceptable to the aluminum industry. It is

Jan 1, 1941

By J. B. Clemmer

This report summarizes the results of u laboratory study of the beneficiation of Arkansas bauxite by flotation. Although the investigation is not yet completed, a preliminary retort of the results on several typical bauxites is presented to show the merits rind limitations of flotation for the production of concentrates acceptable to the aluminum industry. It is

Jan 1, 1941

By J. A. López-Molina, S. García, V. Castellanos-Pedroza

"Grouting aims to reduce the permeability of rock mass below a predetermined value and has been widely used in rock engineering field for a long time. However, the injection procedure needs several empirical decision makings and it is rather difficult to reliably confirm the achievement of improvement, because the grout penetration process is not sufficiently clarified. This investigation proposes a neuronal method of defining spatial distribution of rock hydraulic properties and a fuzzy scheme for estimating their relation with the grout penetration (consumption, localization and filling material). The intelligent method stands as a tool for helping in harmonizing the sealing activities and the medium conditions. The virtual simulation of grouting strategies embraces geology, hydraulic and rock characteristics and the filling process. Important aspects as different pressure injection levels and fracturing systems can be holistically studied using the intelligent environment, resulting in an advantageous, economic, flexible and interactive tool for planning better this critical activity.INTRODUCTION Grouting is a very common method of sealing rock and repairing concrete structures (Butron et al., 2010) and its use in engineering of dam-foundation and tunneling has been documented as very successful (Yang, 2004). Generally speaking, to achieve the closing purpose, boreholes are drilled into the rock mass and grout is injected (under pre-selected pressure) until the fractures around the borehole are filled. The complete filling of these fractures is possible if they are connected to each other in such a way that the remaining water and air can be displaced outside the designed grouting zone (Houlsby, 1990; Kutzner, 1996). Water testing is necessary for evaluating seepage potential and for determining whether grouting is necessary or practical. Regardless of the main reason for the investigations, design of a program for water testing for grouting should consider the type of structure to be built, the geologic conditions at the site and the level of seepage control desired. As information gathered the report must content the fracture openness, number and connectivity, exploratory drill holes orientations, materials situation and a panorama of rock-mass state (quality)."

Jan 1, 2015