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By F. S. Kendorski

This report covers the work on developing criteria for determining when a hazard exists when mining stratified mineral deposits beneath bodies of surface water. The nature of water bodies is considered, the disturbance to the strata induced by mining is described, inundation case histories reviewed, reasonable water inflows derived, and methods of mining to prevent or minimize the hazard are presented. Criteria are given whereby effected industries and agencies can recognize a potential hazard and plan a mine accordingly, releasing considerable mineral reserves otherwise considered unminable.

Jan 1, 1979

By R. Singh, M. Roy, D. Singh

Success of a blasting pattern in Blasting-off-the-solid (BOS) in Bord (Room) & Pillar method of coal mining is judged by the percentage of pull achieved vis-à-vis the yield of coal produced in a blasted round. Improper blast design and distribution of explosives in shot holes normally causes poor breakage i.e. a major portion of shot holes left unbroken resulting into reduced yield per blast. Over and above the disturbance to the roof is also due to excessive vibration caused by explosive energy not properly utilized in fragmentation.

Jan 1, 2003

By Martín Antonio Encinas‐Romero, Patricia Guerrero‐Germán, Jesús Leobardo Valenzuela‐García, José R. Parga‐Torres, María A. Bracamontes‐Landavazo, Agustín Gómez‐Alvarez

A study was carried out to process a sulfide mineral concentrate from Norwest of Mexico containing 97 g/t Au, 0.15% Cu, and 15% Fe. An oxidative acid pretreatment was investigated using ferric sulfate as oxidant, followed by leaching of gold with sodium cyanide. Scanning electron microscopy, SEM-EDS, and X-ray diffraction, XRD, the analysis confirms the presence of quartz and pyrite species. First, a leaching was carried out without pretreatment, at ambient conditions, T = 25 °C and P = 1 atm, obtaining only a 45.2% gold extraction. Once the presence of Fe and Cu sulfides had been confirmed, the Eh-pH diagrams were constructed for the Fe-S-H2O and Cu-S-H2O systems, where it is appreciated that pyrite and chalcocite can dissolve with high oxidation potentials and forming sulfur, oxidizing to sulfate at highly acidic conditions. The oxidized concentrate was neutralized and adjusted to pH > 10.5; it was leached at ambient conditions, at different particle sizes, 44, 37, and 26.5μm, achieving an Au extraction of 75% using a concentration of 0.5% NaCN, 26.5μm particle size, 20% solids, and P = 1atm. Then the oxidized material was subjected to different temperatures, 25, 50, and 70 °C, under the same conditions and obtaining Au extractions up to 92% at 70°C. Additionally, the leaching process was compared using an autoclave reactor at moderate pressures, obtaining an increase in the extraction of Au up to 98% in 2 h, at T = 70 °C and P = 0.62 MPa.

Jan 23, 2022

By Pierre L. Labelle

Non electric Dual Delay initiators have revolutionized many aspects of underground mining. The units are used in all types of underground blasting operations. Some operations, due to the complexity and variety of their blasts, have extremely large inventories of conventional non electric products. The Dual Delay system has drastically reduced these inventories and has added an important element of versatility to blast designs.

Jan 1, 1994

By M. R. J. Wyllie, Michael A. Torcaso

With the continued deep drilling of today, increasing numbers of high pressure and high temperature gas-condensate reservoirs are being discovered. Correspondingly, the ranges of properties of gas-condensate reservoir fluids are also being increased. The literature1*'." contains several excellent reviews of the property ranges in presently known condensate reservoirs. When one examines these property ranges, it becomes apparent that the need for reliable data is great if the engineer is to evaluate properly or appraise a gas-condensate reservoir. It is the purpose of this paper to present phase-behavior data that will point out some of the important variables that influence recovery from gas-condensate reservoirs produced by pressure depletion. All these variables may be resolved into two major categories: the hydroc:arbon composition of the reservoir fluid and the physical properties of the reservoir. But the variables which we will consider are those which are usually determined from well tests shortly after discovery and are, consequently, readily available to the engineer. They are as follows: (1) the producing separator gas-stock-tank liquid ratio, (2) stock-tank liquid gravity, and (3) reservoir temperature. Laboratory depletion studies have been performed on several reservoir fluids to illustrate the effect of changes in the cronsidered variables upon ultimate recoveries. The deviation factors, Z, of a series of reservoir fluids were determined experimentally to illustrate their order of magnitude and their effect upon the calculation of in-place reserves existing at high pressurcs and temperatures. The procedures followed in conjunction with the performance of these studies and their associated calculations are illustrated in Fig. 1. For the purpose of this paper, the depletion recoveries are expressed only in terms of pcr cent of initial stock-tank liquid, with the abandonment pressure assumed to be 500 psig. VARIATION OF RECOVERY WITH INITIAL PRODUCING SEPARATOR GAS-STOCK-TANK LIQUID RATIO The producing separator gas-stock-tank liquid ratio has long been one of the principal criteria in assumptions and generalized correlations' used for the estimation of ultimate recovery from gas-condensate reservoirs. Fig. 2 presents a plot of the cumulative recovery of stock-tank liquid at abandonment as a function of the initial producing separator gas-stock-tank liquid ratio. The graphical illustration represents the results of 44 laboratory depletion studies performed on actual gas-condensate fluids. These data are presented not only to illustrate the general trend of ultimate recovery increase with initial producing ratio increase but to emphasize the considerable variation in possible recovery at any given producing ratio. Table 1 presents the properties of two actual reservoir fluids chosen to illustrate the approximate extremities of producing ratios for gas-condensate systems. The fluids designated as A and B exhibited initial producing ratios of 3,400 and 114,000 scf/bbl, respectively. Fig. 3 presents a graphical comparison of the cumulative stock-tank liquid recoveries, calculated from the well-stream compositions and produced volumes for each fluid during depletion. It is to be noted that Fluid A exhibited a recovery of only 16.5 per cent when produced to an assumed abandonment pressure of 500 psig while the corresponding recovery for Fluid B was calculated to be 62.2 per cent. This difference in recovery, which exemplifies the general trend of recovery increase with initial producing ratio increase, is readily explained by consid-

By Diego Ruben Martin

Este trabalho objetivou comparar, por meio de experimentos desenvolvidos em uma fundição, através da adição de três inoculantes diferentes (IM-22 com FeSi-Ba/Zr, G 20 com FeSi-Ba) e IMSR 75 com FeSi-Sr), para observar as características da vida util de ferramentas na usinabilidade das peças, microestrutura e propriedade mecânica. A metodologia da pesquisa se baseou em analisar principalmente pelo processo de fresamento o ferro fundido cinzento GG-25 inoculado diferentemente, denominado de acordo com a Norma DIN EN 1561. As formas de avaliação dos resultados terão como base uma análise quanto ao desgaste da ferramenta, acabamento superficial, análise microestrutural, composição química e propriedades mecânicas do material da peça. Os resultados mostraram que dentre os inoculantes aplicados o com Sulfeto de Estrôncio (SrS) apresentou-se mais estável termodinamicamente que as amostras inoculadas com os outros dois inoculantes, pois ele levou a uma variação da energia livre de Gibbs mais negativa e portanto mais favorável a formação de núcleos com raio crítico (rc) maiores, o que permitirá uma solidificação com nucleação heterogênea. Todavia o respectivo inoculante também foi mais eficiente na formação de uma microestrutura mais estável, com maiores quantidades de células eutéticas e vida útil do inserto mais longa quando usinado.

Aug 16, 2017

During the lifetime of an open pit mining project, each stage from exploration activities to exploitation and mine closure produces disturbances on the mining region. Mined land reclamation plans establish constructive solutions to rehabilitate the disturbed areas. Open pit mining as an effective method for exploitation of a wide range of orebodies especially for massive reserves of shallow metallic substances has exhaustive and harmful environmental effects on the mining project region. Nowadays, closure and reclamation stage in a mining project is emphatically enforced by the relevant environmental protection regulations in many countries. It is therefore obvious that closure and reclamation costs of an open pit mining project, as costs of other stages of project, must be estimated to enter the planning and design processes in open pit mining. Post-mining land use is the most important factor to recognise closure and reclamation costs. Thus, using a model to define optimal land use in planning phase of an open pit mining project is necessary in this regard. In this project a model was developed to define optimal land use regarding different sections of open pit mines such as pit(s), waste dump(s), tailing pond(s), roads, areas for onsite facilities and free land zones which are not mined. TOPSIS and PROMETHE techniques were applied to create the developed model. Lumber production was recognised as the optimal post-mining land use for the pit area of the case study in this project.

Dec 6, 2010

By J. J. Gresham

Homestake’s first links with Australia were established in 1934 but it wasn’t until 1961 that the company established a formal presence in the country. After involvement and success in iron ore and nickel, Homestake made a strategic investment in the Kalgoorlie gold operations in 1975 and now owns 50% of Kalgoorlie Consolidated Gold Mines, operators of Australia’s biggest gold mine. In 1998 Homestake acquired the major Australian gold producer Plutonic Resources, is now firmly established as Australia’s second largest gold producer and is actively seeking further opportunities for growth in the Austral-Asia region. Homestake’s success in Australia has been the result of important strategic alliances, timely investments, a long term commitment to the region and perseverance during periods of depressed commodity prices.

Jan 1, 2001

By Wenshan Zhang

Three important methods of removing Fe in hydrometallurgy of zinc, manganese, copper, nickel, cobalt and etc are described, including neutralized hydrolysis method, jarosite method and goethite method. The reactions, technical requirements and thermodynamic analysis during Fe removal process are also discussed in this paper.

Jan 1, 2006

By Sam Tour

WHAT is a die-casting and what is the die-casting industry? From the literal translation of the words "die" and "casting"' one concludes that a die-casting is a casting made in a die. The casting may be of any metal or alloy or, for that matter, may be of some nonmetallic material capable of being cast, such as plaster of paris or glass. The die may be of any material that will take successive casts so it need not necessarily be metallic in nature. The term "die-casting," therefore, is indeed broad, though in practical usage it has come to mean the casting of metals and their alloys in metallic molds or dies. Even this limitation of the term leaves -a broad field, for castings may be made in a number of different ways. For example, the molten metal may be allowed to run into the die by gravity it may be sucked into the cavity of the die, it may be forced to take the contour of the cavity in the die by centrifiugal force, or it may be forced into the cavity under hydrostatic pressure. In England, castings made by practically all of these

Jan 1, 1935

By K B. Quast, A Schuurmans

Laboratory batch rod and ball milling tests were conducted on samples of Heavy Medium Separator (HMS) sinks from Renison Limited. The effects of mill rotation speed, rod volume and ball size on the resulting product size distribution were investigated. Between 48 and 69 per cent of critical speed, the product sizing distribution curves remained very similar, with a finer grind resulting from increasing the speed of rotation at constant grind time. Increasing the rod loading from ten to 53 per cent by volume caused the product size to become finer and more closely sized with a transition occurring at approximately 29 per cent. This was interpreted as a change of dominant grinding mechanism from abrasion to impact. No preferential grinding of the cassiterite was observed. The effect of increasing ball size at constant charge weight was to preferentially grind the coarser particles and generate more intermediate sized particles, whereas the product from a mixed ball charge gave a distribution similar to that obtained when a charge containing only smaller balls was used.

Jan 1, 1998

This article presents a proposal for the rehabilitation of the mined area of the Mogiana quarry. The Mogiana quarry produces material used in civil construction and is situated in the Brazilian State of Spo Paulo in the kilometre six of the Mogf Mirim - Itapira highway. The mineral exploitation in the Mogiana quarry provokes modifications in the environment such as alterations in the relief, vegetation, quality of the air, water and landscape. Through previous study of the area it was verified that after the closure of the exploitation the mine should be occupied mainly by pasturage. At the closing of the mine the exploitation benches, berms and slopes in general as well as the surrounding areas should be covered with a layer of soil and vegetated with native species in order to mitigate the negative impacts caused by the mine. The rehabilitation project of the area is based on the probable future use of the area, located between agricultural cultivations and cattle creation. The great alteration of the relief and soil would make future use of the area for agriculture difficult. It is more suitable t0 animal creation, mainly cattle. The high and thick rock slopes originated by the mining should be covered by vegetation, where possible, to reduce the negative visual impact. Obviously several measures will be necessary to reduce the impacts on the environment during mining. The final and definitive reclamation will only be possible after abandonment of the area. The main aspects of this reclamation process will be discussed in this paper.

Dec 6, 2010

By ATF Publications

The following is a summary of the changes that were incorporated into the new Federal Explosives Regulations, 27 CFR Part 55, dated 9/2000. However, in light of the recent events of September 2001, additional changes in the Federal Explosives Laws and Regulations may be forthcoming. The nature and extent of any such potential changes are impossible to gauge at this time. However, this synopsis of the changes contained in the September 2000 Orange Book, ATF P 5400.7 was current at the time of this writing. Any questions regarding this paper should be directed to the Public Safety Branch in ATF Headquarters in Washington, D.C.

Jan 1, 2002

By H. S. COOLEY

TO talk about a "factor of economy" in connection with the wire ropes used in mining practice may be coining a new phrase. If such be the case it needs no other apology than that economy in wire rope usage is so bound up with the factor of safety as to justify a similarity in naming that makes one suggest the other. At the latest Wire Rope Research Conference, held under the auspices of the A. S. M. E., Re- search Committee and Engineering Foundation, data were introduced covering mine ropes working under

Jan 1, 1930

Clean Diesels fuel-borne catalyst, Platinum Plus, helps improve fuel economy for all engines up to 10 percent while reducing particulate emissions by up to 25 percent. When used with a simple diesel oxidation catalyst, particulate emissions can be reduced by 30 to 50 percent. The use of Platinum Plus enhances combustion in the cylinder, burning fuel more completely. This reduces CO2 and other greenhouse gases and lowers total operating costs by improving fuel economy.

Jan 1, 2007

By A. D. Davis

The former Homestake gold mine at Lead, South Dakota, has been selected by the National Science Foundation as the proposed host site for the Deep Underground Science and Engineering Laboratory. The deep laboratory and associated research campus will be developed at approximately the 7700-ft level. Plans also include the development of the Sanford Underground Science and Engineering Laboratory at the 4850-ft level. After the mine?s pumps were shut off in June, 2003, water levels rose to approximately the 4650-ft level by early 2008. Pumps in the 8150-ft deep mine were turned on again for dewatering in April, 2008. Instrumentation is being installed in the mine to measure water-level declines during pumping, for later analysis of permeability and related hydraulic properties of the formation. Pressure-sensitive transducers and data loggers will provide real-time information on water levels that will be available to interested parties. Quality of the water also will be monitored as it is pumped from the mine. I

Jan 1, 2009

By F. Calizaya

The PT Freeport Indonesia‘s Deep Ore Zone(DOZ) copper deposit is located in the province of Irian-Jaya, Indonesia. Currently, a block cave mine is being developed around this deposit. Production is scheduled to start in year 2000 and to ramp up to25,000 tpd by year 2003. The air quantity requirement for this mine is equal to 780 m3/s. To supply this quantity, the mine will require five centrifugal fans (one 450 and four 750 kW fans). This study summarizes the technical aspects related to the installation and commissioning of one of these fans. The fan was installed on the surface in a parallel arrangement with two others. It has a design capacity of 240 m3/s of air at 2.2 kPa of static pressure. The study presents the installation details from the underground shaft excavation and portal development through fan testing and commissioning. It also presents the results of a monitoring system that was installed to determine the fan duties.

Jan 1, 2000

Effects of Hydrated Mg2+ on KCl Flotation

Sep 13, 2010

By Kunihisa Katsuyama, Yuji Ogata, Yuji Wada

The one free surface blasting of a concrete block was simulated by Discontinuous Deformation Analysis(DDA) method. Comparing the simulated results with the concrete block blasting experiment, the crack growth and the free surface displacement which were simulated by DDA were observed with a high speed camera.

Jan 1, 1996

By D. M. Loring

Radon progeny have been a health and safety concern for miners since the mining of radioactive minerals began. Through the ?nuclear age?, it has become better understood and the regulations have become more robust. Ventilation and control practices have improved, thus reducing miners? exposures. This paper provides an overview of radon in mining, the progress of the regulations, and discusses some of the uranium miner studies that contributed to the knowledge of the pathology of radon.

Jan 1, 2009