Search Documents

To develop a reliable, remotely-controlled, mobile roof support to eliminate the need to set posts, cribs, or props while extracting coal pillars. Approach The primary danger during pillar extraction is premature caving of the mine roof. The roof must cave predictably and dependably to ensure the safety of miners. Support during retreat mining is usually obtained by setting posts, cribs, props, roof bolts, or a combination of these devices. These are set manually by miners in the working area. To help minimize the danger to mine workers and to equipment posed by premature falls, the Bureau of Mines developed the mobile roof support (MRS) system to secure the roof during pillar extraction. How It Works The Mobile Roof Support (MRS) is eight-feet-wide, ten-feet-long and five-feet-high, with twelve inches of ground clearance. It is ruggedly built and exerts less than 20 psi ground pressure. The MRS is powered by a 40-hp, 460-v AC permissible motor. The reversible, variable tram speed is 80 ft/min on a 20-percent grade. It is tire-mounted, has a trailing cable, and is remotely controlled either by a radio or a tether communication cable. The machine carries four 50-ton jacks which serve as props for working heights from seven to fifteen feet. Two jacks are chassis-mounted and two are on swing arms. Each jack has a cap which distributes the roof load to three paints. The swing jacks form a breaker row to stop falling roof and prevent caving Into the work area. One jack has a visual load indicator and a second is wired to the machine lighting system. Blinking lights indicate when the preset loading is being exceeded. In the case of excessive loads, an ability to remotely jettison either or both swing jacks has been incorporated into the system to permit removal of the MRS while the roof is still supported.

Jan 1, 1985

By H. M. Smith

The production of oil during the early development of new oil fields is usually accompanied by large quantities of natural gas. Since in most fields gas under pressure is the main source of the energy causing the oil to move through the sands into the wells and thence to the surface, coincident production of natural gas will continue as long as present-day producing methods are used. Generally the use of this gas is restricted, since markets are not readily available. Consequently, a large portion of the gas produced is often wasted by being blown into the air. The magnitude of gas waste is well brought out in the following statement by Miller:5 Only a few outstanding examples need be cited to show the enormous production of gas that accompanies the discovery of new sources. In April, 1927, the Ventura field produced approximately 210,000,000 cubic feet of gas a day; and during the summer of 1927 Alamitos Heights reached a peak gas production of 102,000,000 cubic feet a day; on December 1, 1928, as a result of the summer's deeper drilling in the Long Beach field, surplus gas production amounted to 125,000,000 cubic feet a day. It is estimated that in January, 1929, the Santa Fe Springs field will have a daily gas production of 387,000,000 cubic feet from the recently discovered Buckbee oil zone. Of this amount 274,000,000 cubic feet a day will be the surplus above the amount required for field and plant fuel, taken out by utility corporations, and that used in repressuring the Meyer sand which lies above the Buckbee zone.

Jan 1, 1931

By C. J. H. Brest van Kempen

The objective of this contract was to provide thrust and torque control and visual output torque readout systems to an existing mine roof bolting machine and to test the consistency of torques obtained under actual field conditions. A Lee Norse TD1 roof bolter was modified by adding a simple torque sensing device to the drill rotation mechanism and a pneumatic logic control circuit that measures torque and controls the hydraulic circuit to the rotation motor. The modification controls and indicates the final installation torque of mine roof bolts. A total of over 5,000 mechanical roof bolts were installed in an operating coal mine. The installed torque of these bolts were within an error band (standard deviation) of 8%.

Jan 1, 1978

By S. Oppenheimer, P. Au, R. M. Kearsey, J. Tsang, E. McDevitt

A new superalloy, ATI 718Plus® Alloy (718Plus), has been developed to have a 55oC higher temperature capability over the traditionally used Alloy 718, while maintaining favourable processing characteristics and intrinsic raw material costs. The fatigue and dwell-fatigue behaviour of four microstructural variations of 718Plus are evaluated and compared to Waspaloy: 1) standard heat treated condition (HT1), 2) standard heat treated condition with thermal exposure at 732ºC (1350ºF) for 1000 hours (HT2), 3) fine grain condition with a modified d phase (HT3), and 4) fine grain overaged through modified heat treatment (HT4). The results show that the steady-state fatigue crack growth rates of each microstructural variation and both alloys are identical, with all of the 718Plus variations showing a clear advantage over Waspaloy in the fatigue crack threshold regime. Dwell-fatigue results show that Waspaloy has better resistance to crack propagation under dwell conditions; however, optimization of the precipitate phase shows vast improvement in the dwell-fatigue resistance of 718Plus.

Jan 1, 2010

By K. Yamaguchi, Y. Takeda

"Partial pressure - temperature - composition correlation diagrams of the Ga-As, In-As, Ga-P and In-P systems were contracted based on the obtained experimental data of the phase diagram and thermodynamic properties for the III-V systems. The total vapor pressures of arsenic or phosphorus at melting point of GaAs, InAs, GaP and InP were determined as 101, 10.1, 1510 and 253 kPa, respectively, at the corresponding melting points of 1509, 1211, 1739 and. 1336K , These diagrams are applied to the analysis of the horizontal Bridgman method and the liquid phase epitaxial growth technique. On the other hand, the analysis of the equilibrium state of the. chloride-CVD process was carried out using the data of the Gibbs energy of the compounds obtained by· authors.IntroductionThe group III-V compound semiconductors ate important materials used in optoelectronic liquid high speed electronic device. The crystal growth of the III-V compounds can involve processes that require contact between the solid, liquid and vapour phases at near equilibrium condition. Examples of processes that involve contact between the solid, liquid and vapour phases include bulk crystal growth such as the horizontal Bridgman and the liquid encapsulated Czochralski method and liquid epitaxy, and between the solid and vapor include chemical vapour deposition and molecular beam epitaxy. Therefore, the knowledge of the phase diagram and thermodynamic properties for the III-V binary alloys is essential for the analyses of crystal growth techniques of III-V compounds.For these reasons, a series of different · types calorimetric measurements had been carried out: (1) The heat contents of alloys for the Ga-As, In-As, Ga-P and In-P systems by a drop calorimeter [1;2,3]; (2) the heats of formation of the GaAs, InAs, GaP and InP compounds by a twin solution calorimeter [4]; and (3) the standard entropy of these compounds by an adiabatic calorimeter [5]. Based on the third law method, the Gibbs energies of these compounds were derived from the heat capacity, standard heat of formation and standard entropy data obtained by authors. Integral molar thermodynamic quantities of the liquid III-V .alloys were also determined from combining the heat contents of alloys with standard heat of formation and standard entropy data of the compounds· by applying the thermodynamic analysis method developed by Oelsen [6]. In the present study, the thermodynamic calculations for the crystal growth processes of the III-V compound were carried out using newly experimental data of the phase diagram and thermodynamic .properties measured by authors"

Jan 1, 2000

By Alan D. Smith

[A standardized checklist in a questionnaire format, was established to investigate selected factors associated with coal nips roof falls, as derived from an intensive review of the literature. A plot study was undertaken to aspect and explore possible statistical relationships that may exist with these parameters. the Purposes of toe study were to: 1. Study in a systematic and empirical fashion selected parameters that may be capable of differentiating characteristics of roof falls; 2. Obtain some predictive indices cased on selected physical and management related variables so that predictions of future problems associated with mine roof falls can be completed, prior to its actual occurrence. Accomplishment of these goals should result in valuable guides to the mining engineer in scheduling exploration work and 4 determining economic feasibility of certain ground control and .lining pro and practices. The parameters associated with mine roof failure that where included in the questionnaire are: working section, county, spar., orientation degrees), pillar dimensions width, length), seam thickness, roof fall dimensions (length, width, surface area, volume), shape of fall (arch, dome, laminar), thickness of thinnest immediate layer, lithology of the first four i.e.-diate roof layers, thickness of h e first four immediate roof layers, type of initial support systems before failure, type of resupport system after failure, length and spacing of bolts in use before failure, length and spacing of bolts planned after allure, presence of .cater, time failure after It coal excavation, distance t3rest ace, physical operation during, time of coo failure, location of the roof fall entry failure occurred ence of sloughing of ribs before failure, and presence of floor heave condition before failure. The typical roof fall had an average roof spar of 20.3 feet, -06 feet depth o coal seam, occurred 136 feet from nearest face, coal seam thickness of inches, p--ar :width off 45 feet surface area D' roof fall 1151 ft2, mainly lamin- shaped, previously rat fore fall between good to very good, little floor heave presence, usually cracks before the fall about 40 percent of reported cases, shales in most of the immediate layers, and usually located in an entry or intersection. in addition, multiple linear regression techniques were employed in the testing process of 18 major research hypotheses in a search for relationships among the various parameters studied of which were found to be significant, once corrected for multiple comparisons.]

Jan 1, 1984

By T. J. Ballard

"INTRODUCTION The Buck. Creek corundum area of Clay County, North Carolina, includes one of the largest single masses of peridotite outcrops in the whole Appalachian Range and has been described by Pratt, an early authority on corundum, as offering one of the best potentialities for corundum production in North Carolina.Two principal types of corundum deposits are found at Buck Creek the vein type and the corundum-bearing amphibolite dikes.The vein deposits occur in structural fissures that strike north to northeast in a gangue of feldspar, zoisite, an, chlorite. The corundum is generally coarse-grained and good-quality. The corundum content varies from several percent to 50 percent.The corundum in the amphibolites is more or less disseminated through the dike, is generally lower-grade, and is less in quantity, than the vein corundum. About 50 percent of the amphibolite corundum is coarse enough for snagging-wheel grade but is difficult to separate from the amphibolite.Production from the Buck Creek area has been small and came mainly from high-grade pocket in the vein deposits. Pratt 3/ reports 300 tons of corundum ore was produced to about 1896. No record of subsequent production is available.The critical shortage of corundum during the war, due to transportation difficulties and the depletion of deposits abroad, prompted the Bureau of Mines to investigate domestic reserves.After a favorable report was obtained on the Buck Creek area, the Bureau began exploration of the deposit in September 1943 and continued until February 1945."

Apr 1, 1947

Have your name and address on the first page of your manuscript. Typewritten manuscript is preferred, but is not essential. If you have the manuscript typewritten, have it double spaced and written on one side of the page only; send two copies to us if convenient; only one copy of the illustrations is desired. In typewritten manuscript, formulas are better inserted by hand. Keep a copy of your manuscript in case of loss in the mail. ILLUSTRATIONS.-Photographs reproduce best when printed on glossy paper. Solio is one of the best varieties. A good print is preferable to a negative. Blueprints, drawings, or pen or pencil sketches can be used for line engravings, but care should be exercised to make them legible and clear, especially in the case of blueprints. Tracings or photographs of drawings are preferable to blueprints. Rough sketches can be used, if necessary. Photographs should be sent flat, not rolled. Do not put reference letters or other marks on photographs; if such letters or marks are necessary, fasten a piece of tracing paper to the top edge, trace a rough outline of the picture upon it and then place all letters, etc. on the tracing paper lithe exact position you wish them to appear. Restrict the number of micrographs as much as possible on account of the considerable expense involved. Standard magnifications for non-ferrous metals and alloys are recommended as follows: 10, 25, 50, 75, 100, 150, 250, 500, 750, 1000, 1500. Micrographs should be trimmed to 2 1/4 X 2 1/4 in. (six micrographs to a plate), or, if larger, up to 3 1/2 X 4 in. (two to a plate). The smaller size should be adopted if consistent with adequate representation of the subject. With each micrograph should be attached an explanatory title, together with the actual magnification, etching medium, treatment, etc., indicating what the author intends to show.

Jan 1, 1919

By J. T. Ryan

FIGURES for the first 11 months of 1935 indicate that the total coal production of the United States for 1935 will be approximately 416,000,000 tons, or almost identical with the production figures for 1934. Bituminous production will show a gain of about six million tons, and anthracite production a loss of about the same tonnage, compared with the previous year. This does not take into account so-called "bootleg" anthracite coal amounting to approximately 5,000,000 tons. Twenty-nine years ago, in 1906, the production of coal was almost identical with this year's production. At that time, 626,000 men were employed in producing this tonnage, which took a toll of 2138 lives from accidents. In 1935, approximately 540,000 men were required to produce the same tonnage with an estimated loss of 1155 lives. This shows definite safety advancement in the industry, but even so accidents are still costing an average of 3c. a ton more than they should.

Jan 1, 1936

By A Muhairini, M Eggers, J Smith, H Baxter

Detailed geochemical analysis of cored and non-cored drill hole data was used to characterise and model the Cenozoic detrital valleys of several deposits within the southern Pilbara region, Western Australia. The purpose of this modelling was to better characterise and understand the relationships between the various geotechnical units comprising mixtures of rock and soil for the purposes of slope stability and depressurisation studies.This paper presents data from several valleys where geological, geomorphological and climatic processes have resulted in the deposition of heterogeneous detrital rock and soil sequences. Seven primary detrital units are recognised as occurring within all the valleys studied, suggesting that the geological processes involved in the erosion and deposition of the units were widespread. Geochemical assessment of cored and non-cored data suggests correlatable geochemical signatures can be recognised for each of the units; however, local variability in the groundwater history of individual valleys is demonstrated by late-stage carbonate precipitation recognised both in the core and through the geochemical signatures, which has resulted in alteration of the parent rock/soil material. This paper discusses how the carbonate alteration may lead to improvements in rock/soil mass strength of a clay unit by comparing laboratory strength test samples of the same parent material with varying degrees of precipitate alteration to those with no discernible carbonate alteration. Following from this, correlations with geochemical assay results have been derived, whereby zones of more favourable strength conditions may be modelled through assessing areas of analogous geochemistry.The paper demonstrates how geochemical assessment can lead to improved geotechnical and hydrological modelling for a detrital valley system without the need for significant coring and laboratory testing. This in turn leads to improved confidence in the slope design and depressurisation recommendations for a slope.CITATION:Baxter, H, Eggers, M, Muhairini, A and Smith, J, 2015. The effect of carbonate alteration on detrital mass strength and implications for geotechnical slope design, in Proceedings Iron Ore 2015, pp 429–436 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Jul 13, 2015

By H. E. Powell

Basic data were recorded on the decompositions that take place during thermal decomposition of siderite (FeC03). Both the naturally occurring and a synthetically prepared mineral were studied by differential thermal, thermo-gravimetric, X-ray-diffraction, and chemical (including gas) analyses. Thermal decomposition was studied in the media of dry air, moist air, dry carbon dioxide, dry helium, and dry carbon monoxide and at atmospheric and at reduced pressures. Results showed the thermal decomposition of FeC03 to be an extremely complex process, dependent on environmental factors and side reactions that cannot now be completely controlled. Therefore, full understanding of the reaction involved must depend on additional research with advanced evaluation techniques.

Jan 1, 1965

By Riley S. J

Ranger Uranium Mine is located within the Alligator Rivers Region of the Northern Territory of Australia and surrounded by the World Heritage listed Kakadu National Park (Figure 1). The mining operation is currently producing about 1500 tonnes of uranium oxide annually, as well as considerable volumes of waste rock, low grade ore and tailings. The rehabilitation of the project should ensure that the radioactive mill tailings and other contaminants remain contained for at least 200 years, as required by the existing guidelines (Commonwealth of Australia, 1987). The present uranium mining operation is regulated by the Northern Territory Department of Mines and Energy who must refer to the Environmental Requirements when considering regulatory options. These Environmental Requirements were agreed by the

Jan 1, 1994

By David Mast, Irwan Halim, Seung Han Kim

Fermilab is constructing a large underground cavern in Limestone to house scientific equipment. The cavern will have a complex L-shaped geometry and about 215-foot depth with relatively shallow rock cover, with service/egress shafts accesses into the cavern. Three-dimensional analytical models were developed to study the ground behavior and support performance. Multiple rock constitutive and failure models were evaluated. The models were significantly impacted by the high lateral in-situ earth pressure at the site. This paper will describe the design approaches that were taken to optimize the cavern arch geometry to allow safe construction in shallow rock, and permanent support requirements.

Jun 13, 2021

By K. K. Kelley

Thermodynamics data for silicates have applications in the fields of extractive metallurgy, ceramics, and geochemistry. To facilitate these applications, up-to-date tables of heats and free energies of formation are needed. It is the purpose of this report to supply such tables for anhydrous silicates. During the last 15 years the heats of formation of a substantial number of anhydrous silicates have been reliably determined at or near room temperature. This resulted from the development (first by the Bureau of Mines and later by the Geophysical Laboratory of the Carnegie Institution of Washington, by the Institute of Geology of the University of Helsinki, Finland, and by the Department of Geology of the University of Chicago) of accurate solution calorimeters, employing hydrofluoric acid as the reaction medium. Specific references to work of these laboratories will be made in the next section of this report. Also, entropy data at 298.150 K. and high-temperature heat-content values are available for many of these silicates, mainly owing to work of the Bureau of Mines. Most of these entropy and heat-content data have been compiled in Bureau of Mines Bulletins (13, 15).3

Jan 1, 1962

By W. B. Lambert

A common decision in openpit mining is to determine the extraction sequence of notional three-dimensional production blocks so as to maximize the net present value of the extracted orebody, while adhering to precedence and operational resource constraints. This openpit block sequencing (OPBS) problem is commonly formulated as an integer program, with binary variables representing if and when each block is extracted. In practical applications, the number of blocks can be large and the time horizon can be long; therefore, instances of this problem can be difficult to solve using the exact approach of optimization. The problem is even more challenging to solve when it includes explicit minimum operational resource constraints. Our maximum value feasible pit (MVFP) algorithm generates an initial integer feasible solution for OPBS problems, in which minimum operational resource constraints are strictly enforced. As an exact approach, we present a Tailored Lagrangian Relaxation (TLR), in which the selection of constraints to dualize is guided by information provided by the MVFP algorithm. We present results and graphics to demonstrate the utility of our techniques for instances containing up to 25,000 blocks and 10 time periods.

Jan 1, 2013

By G. G. Brown

Enthalpy-entropy diagrams are presented for natural gases of 0.6, 0.7, 0.8, 0.9, and 1.0 gravity over the pressure range of 5 to 10,000 Ib. per sq. in. and temperature range of 32º to 700°F. The charts indicate directly the work requirement and temperature rise for adiabatic compression or temperature change for free emansion of natural eases. Computation and Uses of Charts The Mollier diagram (Fig. 4), in which the enthalpy (heat content) is plotted against the entropy with lines of constant temperature, pressure,, and in some cases volume, has been found most convenient when dealing with the compression, expansion, and flow of fluids. In dealing with the flow of fluids, the sum of the increase in the enthalpy, AH, plus the increase in kinetic energy, AM —, plus the increase in potential energy, ?MZ, representing the total increase in energy of the fluid in flow, is equal to the sum of the heat q, and work added, —w, to the fluid while flowing between the entrance and exit of the flow system. AH + AM— + ?MZ = q-w [1] In cases where there is no significant change in potential energy or in kinetic energy (velocity), it follows that the increase in enthalpy is equal to the total energy supplied to the fluid. Under such conditions' the changes in the property of the fluid as it flows through a throttling valve, choke, or any other similar arrangement, may be read directly from the enthalpy-entropy diagram by following a horizolltal line between the known pressures' When compressing Or expanding a gas by means of a Or or engine in which no heat is added to or subtracted from the gas, but only work done, the changes in the properties of the gas may be determined along a vertical line of constant entropy between the entering and exit pressures. The power required for the compression of the gas may be readily determined by converting the increase in enthalpy into the desired units. The enthalpy-entropy diagram for natural gases is to the gas engineer what the steam diagram is to the steam-power engineer. For this reason it would be extremely convenient if a reasonably satisfactory enthalpy-entropy diagram could be prepared as a function of the gravity of the gas. A careful study of the known properties of natural gas indicate that this is possible. The effect of temperature upon the enthalpy at constant pressure is expressed as the "heat capacity" or "specific heat" of the gas. The best available data for natural and petroleum refinery gases indicates the relationship shown in Fig. I. From this it is clear that the specific heat of natural gases is a function only of the gas gravity and the temperature at atmospheric pressure. The effect of pressure on the enthalpy of natural gases is dependent upon the pressure-volume-temperature relationships,

Jan 1, 1945

By M. Dadvand, G. Kipuros, A. Dadvand

"The ability to codeposit fillers within a nickel matrix has led to the production of a new generation of cermet coatings with properties useful for various applications. Hexagonal boron nitride (hBN) is a ceramic-type particulate matter with thermal conductivity, thermal stability, inertness, and lubricity properties that allow it to be codeposited. In this paper, a method was developed for modifying hBN surfaces to allow them to be uniformly dispersed in water-based solutions such as an electroless nickel plating bath. hBN surface modification improved wear performance of the electroless plated cermet due to enhanced interaction between the particulate and nickel matrix. RÉSUMÉ La capacité à effectuer un dépôt simultané de charges dans une matrice nickel a abouti à la production d’une nouvelle génération de revêtements cermet (une combinaison de céramique et de métal) dotés de propriétés très utiles pour diverses applications. Le nitrure de bore hexagonal (h-BN) est une matière particulaire de type céramique utilisée pour ses excellentes conductivité et stabilité thermiques, son inertie ainsi que son caractère lubrifiant, qui permettent son dépôt simultané. Cet article explore une méthode mise au point pour modifier les surfaces du h-BN de manière à ce qu’elles se répandent uniformément dans des solutions aqueuses telles qu’un bain de dépôt autocatalytique de nickel. La modification des surfaces du h-BN a amélioré la résistance à l’usure du placage autocatalytique du cermet en raison d’une interaction accrue entre la matière particulaire et la matrice nickel.INTRODUCTION Electroless nickel alloy coatings can be used for many applications; however, the need for improved tribological properties such as higher wear resistance and better lubricity has increased interest in incorporating particulates (fillers) into the nickel matrix by codepositing the particulates with nickel during the plating process. The selection of the particulate type depends on the desired properties (Sahoo & Das, 2011; Sudagar, Lian, & Sha, 2013). In terms of tribological applications, electroless nickel-based composites are categorized mainly into lubricating and wear-resistant composite coatings depending on the type of particles incorporated. The electroless nickel-phosphorus (Ni-P) composite coatings are composed of codeposited solid lubricants such as polytetrafluoroethylene (PTFE), graphite, WS2, MoS2, and hexagonal boron nitride (hBN) and, compared to nanocomposite electroless Ni-P coatings, they demonstrate a lower coefficient of friction. On the other hand, the nickel-phosphorus wear-resistant composite coatings are composed of hard particles such as silicon carbide (SiC), aluminum oxide (Al2O3), boron carbide (B4C), silicon nitride (Si3N4), diamond, tungsten carbide (WC), and zirconium oxide (ZrO2) and, compared to nanocomposite electroless Ni-P coatings, they have higher hardness and better wear resistance (Sahoo & Das, 2011; Sudagar et al., 2013; Parucker, Klein, Binder, Ristow, & Binder, 2014; Chakarova, Georgieva, Petrova, Dobreva, & Stoychev, 2016)."

Jan 1, 2018

By M A. Harrington-Baker, J M. Trudnowski

Sulfate-reducing bacteria (SRB) have the ability to immobilise dissolved metals by precipitating them as sulfides, provided that a favourable biochemical environment is created. Such an environment includes the presence of sulfate, anaerobic conditions and the availability of organic carbon. If such conditions are engineered within a reactive barrier or field-bioreactor, most metals can be effectively removed. To demonstrate this concept, three passive SRB field-bioreactors were constructed in 1998 at an abandoned mine site in the vicinity of Butte, Montana, USA to treat acid mine drainage with characteristic elevated concentration of metals and low pH. Performance of the field-bioreactors, using aqueous samples, was monitored over 32 months until the project was terminated, field-bioreactors were decommissioned and solid matrix sampling of the reactive matter was performed. The most important analytical results are presented in this paper together with conclusions regarding the appropriateness of the field-bioreactors construction features. Only Zn, Cu, and Cd were being removed as sulfides due to SRB activities. Changes in concentrations of other metals (Fe, Mn, Al, As), which do not necessarily precipitate as sulfide, seemed to be affected by SRB only in an indirect manner by responding to increased pH caused by SRB activity. An innovative cellular containment system used for placing organic matter worked very well in preventing settling of the organic matter and ensuring uniform flow of AMD throughout the entire cross-section of the organic carbon with no preferential flow paths This demonstration was funded by the US EPA and was jointly administered by the EPA and the US DOE under DOE contract number DE-AC22-96EW96405. The project was implemented by MSE Technology Applications, Inc, Butte, Montana, USA.

Jan 1, 2003

In view of the increasing environmental regulations that have been promulgated all over the world in the last 30 years, non-ferrous smelters and refineries have learnt and adapted to treat effectively metals'-containing process waste streams that need to be bled from the plant. However, anions such as sulfates, chlorides and fluorides-presently not a major problem ?are coming under increasing scrutiny and need to be addressed in the near future. The current paper reviews options for waste water treatment with reference to: a) types of waste streams processed b) process chemistry c) discharge options d) recovery and reuse of water and e) solids disposal. Methods to obtain zero liquid discharge ?a possible solution to eliminate discharge of above anions and residual heavy metals- are discussed with case studies. The long term goal of any non-ferrous smelter plant should be to have a zero liquid discharge philosophy-an approach that would become an epitome of water reuse and conservation.

Jan 1, 2009

By Jamie Archibald

The Department of Mining Engineering at Queen?s University conducted a study of backfill practices in underground mines across Canada to assess the current state of backfill usage and to overview potential hazards associated with backfill practice, from preparation to transportation to placement. The primary aim of this study was to cover each component of a typical mine backfill system, and to identify potential incidents leading to the disruption of backfilling operations and any associated corrective actions. This paper, Part II of the study, deals with underground operations consisting of backfill transportation and backfill placement. Part I of the study, which deals with surface operations consisting of backfill material supply and backfill plant preparation, is also presented in these proceedings. A review of safety measures associated with current backfill operations and recommendations for procedures of best practice that should be implemented to reduce fill-related hazards in all mine backfill workplace environments are presented. In general it has been found that system failures normally lead only to minor losses to the operations.

May 1, 2009