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By John Dean

"Pumping backfilling medium used to fill in holes and caverns in mines is challenging. The often viscous, high solids materials are extremely abrasive and can destroy pumping systems in a matter of days. While a number of options are available, using a progressing cavity pump can often be the best solution. High pressure and capacity capabilities, coupled with low wear rates, ensures reliable cost effective operation.Thickened slurry backfilling for underground/excavation mining applicationsVoids and caverns develop as a result of mining operations penetrating deep into the earth seeking natural resources. After extracting all the ore from a mine, operators need to fill in these voids to preserve the integrity of the mine structure. They do this by pumping in a backfill medium. Each mine uses a different mix of components for backfilling, depending upon the mine’s specific structural requirements and environmental concerns, particularly water requirements. Most backfill mixes contain cement, or another cement-like substance, that acts as a binder to hold the backfill medium together. This is combined with tailings (unused rocks and waste from processing and/or extraction), and may also include chemicals or other binders to increase the material’s strength.Backfill pumping challengesPumping the backfilling medium can be a significant undertaking. This process involves transporting very viscous and high solid materials; the mix may contain 60-80 percent solids. These backfill slurries are extremely abrasive and the viscous material can wreak havoc with pumping systems. The material’s paste-like consistency presents problems for standard centrifugal pumps often used in other mining applications.Added complexity is posed when trying to achieve the required pressure, which depends upon how far away the material has to be pumped. It is not difficult to meet the pressure requirements if mixing the backfill material close to the area to be filled. However, pumping from extreme distances can be problematic — a great deal of pressure is required to transport the material from the mixing area to a distant backfilling site. Ideally, operators should be as close as possible to where they are filling, so they can use a smaller pump with lower power requirements."

Dec 1, 2018

By R. H. Atkinson, R. N. Rhoda

An improved technique has been developed for the deoxidation of palladium with aluminum which is especially suitable for use in making small castings with an induction-melting and casting machine. The effect of various crucible linings on the efficiency of the residual deoxidizer and accompanying oxide film in protecting palladium against oxidation during remelting also has been examined; the preferred crucible lining consists of zirconia cement. THE objective of this work was to develop a simple method of deoxidizing induction-melted palladium which would be suitable for use by manufacturers of jewelry and other small castings. In a common method of deoxidizing torch-melted palladium a piece of aluminum foil is dropped on the surface of the molten metal. If a film is present, which is usually the case, it must first be removed by oxidizing the molten metal thoroughly because it would interfere with the entry of the aluminum into the melt. Removal of the film is probably facilitated by a mild fluxing action of the silica crucibles which are used for torch-melting. However, removal of an alumina film from molten palladium in the crucibles normally used for induction melting is a much slower process and it became necessary to modify the de-oxidation procedure. In the modified procedure the charge is simply melted and the desired amount of aluminum, crimped to one end of a tungsten wire, is plunged through the film into the palladium and the wire immediately withdrawn. The trace of tungsten which dissolves along with the aluminum can be avoided, if considered objectionable, by using a palladium wire. In view of the persistence of the alumina film under the conditions of induction-melting it also was decided to ascertain the efficiency of this film in protecting palladium against oxidation during repeated remelting and casting. Melting Equipment and Materials The equipment used for melting and casting consisted of an Ecco GC:6, 6 to 8-kva high-frequency converter and an Ecco M34B centrifugal casting machine. This unit is being increasingly used for making jewelry and dental castings and it also has been found useful in making exploratory melts of a variety of nickel alloys, for which purpose it is well suited on account of its speed of melting and economy of material. A description of the machine and its operation will be published elsewhere.' A common palladium jewelry alloy, 95.5 palladi-um-4.5 ruthenium (referred to as "palladium" in the trade), was selected for the deoxidation tests. It was available as melting stock which had been melted in air to free it from oxidizable impurities, and also as clean scrap from previous melts which had been deoxidized with aluminum. The latter was thought to be typical of clean "palladium" scrap to be found in a manufacturing jeweler's establishment and it is also similar to one brand of "casting palladium." By the same token, the oxidized melting stock corresponds to "casting palladium" after the latter has been melted and thoroughly oxidized: Pure aluminum wire (99.9 pet), 0.032 in. diam; 1 in. = 0.036 g. Scrap tungsten wire, 0.014 to 0.020 in. diam. Argon, commercial water-pumped; 99.9 pet pure Experimental Procedure Samples of about 50 to 75 g of the palladium alloy were melted in a crucible lined with a proprietary refractory alumina cement. Some charges were melted in air, others in argon. The oxidized melting stock was melted and solidified a number of times in order to remove as much oxygen as possible before deoxidizing, but this treatment was unnecessary in the case of scrap. In either case the metal was deoxidized with aluminum (0.01 to 0.05 pet) by the

Jan 1, 1959

Minerals are a fundamental component of the Nation" material and economic base. Without a continuous supply of minerals to meet growing and changing needs, the basic character of our society would be very different. The importance of minerals to the United States was reemphasized by the Congress in I970 when it enacted the Mining and Minerals Policy Act, which stated that it is the continuing policy of the Federal Government in the national interest to foster and encourage private enterprise in (I) the development of economically sound and stable domestic mining, minerals, metal and mineral reclamation industries, (2) the orderly and economic development of domestic mineral resources, reserves, and reclamation of metals and minerals to help assure satisfaction of industrial, security and environmental needs, (3) mining, mineral, and metallurgical research, including the use and recycling of scrap to promote the wise and efficient use of our natural and reclaimable mineral recources, and (4) the study and development of methods for the disposal, control, and reclamation of mineral waste products, and the reclamation of mined land, so as to lessen any adverse impact of mineral extraction and processing upon the physical environment that may result from mining or mineral activities.,.

Jan 1, 1977

By L. A. Ruth

Vision 21 is a government/industry/academia cost-shared partnership to develop the technology basis for integrated energy plants that will, early in the 21stcentury, result in the deployment of ultra-clean plants that produce electricity and “opportunity” products. Vision 21 plants will use fossil fuel feed-stocks in combination with other domestic resources, e.g., biomass, municipal waste, and petroleum coke. Opportunity products could include transportation fuels, steam, high-value chemicals, synthesis gas, and hydrogen. Performance targets for Vision 21 plants, example plant configurations, and the key technologies that will be needed are described.

Jan 1, 2000

By Ahmad Ghahreman, Lin Li

Silver and cupric ions have been proven to play the roles of catalysts to promote the oxidation kinetics of chalcopyrite in acid solution. In this study, the interaction between silver ions and cupric ions during ferric leaching of chalcopyrite in sulfuric acid solution has been investigated. The electrochemical study by Tafel analysis showed a significant boost of dissolution rate for chalcopyrite dissolution in Fe3+- Cu2+ containing sulfuric acid solution after Ag+ was added in the solution. For 10 ppm Ag addition, the dissolution rate of chalcopyrite increased to 7.94 ×10-6 A/cm2 from 3.2 ×10-7 A/cm2, when Ag+ was absent. On the other hand, the effect of Cu2+ on the dissolution of chalcopyrite in Fe3+-Ag+ containing sulfuric acid solution was not obvious from electrochemical measurements. The chalcopyrite leaching tests in different acid solutions showed that silver addition had an obvious catalytic effect on promoting chalcopyrite dissolution. Comparing the leaching rates of chalcopyrite leached in Fe3+ containing, Fe3+-Ag+ containing, Fe3+-Cu2+ containing and Fe3+-Cu2+-Ag+ containing sulfuric acid solutions, it was found in Ag+-Fe3+-Cu2+ containing sulfuric acid solution, the leaching rate was highest among all the aqueous acid systems. Further leaching tests suggested that with increase of the Ag+ concentration from 0 to 20 ppm, the leaching rate of chalcopyrite in Ag+-Fe3+-Cu2+ containing sulfuric acid solution also increased and reached 57.62% with 20 ppm Ag+ addition after 24 h. INTRODUCTION Chalcopyrite is the most important copper mineral in copper hydrometallurgy and it accounts for nearly 80% of the universal copper resource (Olvera, Rebolledo, Mora, Dixon, & Asselin, 2018). The hydrometallurgy of chalcopyrite has been intensively studied with emphasis on solving the slow dissolution kinetics of chalcopyrite in acid environment. A variety of aqueous systems, such as sulfate (Hiroyoshi, Miki, Hirajima, & Tsunekawa, 2001), chlorides (Liu, Chen, & Yang, 2017), and ammonia (Hua et al., 2018) have been studied to improve copper leaching. From another perspective, chalcopyrite leaching studies have indicated that the mechanism of chalcopyrite dissolution in acid solution is essentially electrochemical (Li, Kawashima, Li, Chandra, & Gerson, 2013). Therefore, extensive studies have recently been carried out to explain the dissolution kinetics of chalcopyrite in different media by various electrochemical techniques.

Jan 1, 2019

By Joseph J. Zaluski, J. Steven Gardner, Marco M. Rajkovich

The telephone rings at 3:20 a.m. An exasperated voice on the other end says, “There has been a mine explosion at Mine No. 5 and we have not heard from three units of men.” Twenty-three minutes later, the phone rings again and another panicked voice says, “There is something wrong at the slurry impoundment, the pool level has just dropped five feet and we are trying to figure out what is wrong” Thirty minutes later, the mobile phone rings. An excited security guard says, “We have reports of thick black water running down the right fork and left fork of Straight Creek and both seem to be rising in the banks.” If this is not enough excitement, the mobile phone rings again. A stressed company official says, “I just heard a report that black slurry is running out of the portals of XYZ Co. No. 2 Mine, which is adjacent to our No. 5 Mine.” Is this all some kind of dream or nightmare? More importantly, though, if this happens, what do you do? Most people think: “It can’t happen to me.” But mine explosions do happen, slurry impoundments can rupture and creeks can flood with black water causing damage to others, including competitors. A mine’s response must be quick, cool-headed, calculated and effective. This article examines the issues, concerns and ramifications of this hypothetical disaster. The authors then present a systematic crisis-management response.

Jan 1, 2004

Contact Angle Measurements on Lignite Surface

Sep 13, 2010

By A C. Carter

The increasing need for alternative energy sources as well as the less clearly perceived but equally increasing demand for non-fuel minerals has resulted in extensive exploitation of near surface deposits. Many such deposits have depleted reserves and mining corporations are increasingly turning their attention to deposits, with thicker overburden, less competent materials, steeper dips and more complex structure. These deposits pose mine layout, geotechnical and equipment problems as well as the need for large outputs to achieve economies of scale. The paper describes the major problems and operational solutions for such deposits using continuous excavation and transport equipment.

Jan 1, 1980

By A Hekmat, M Fuentes, F Armijo, R Castro, F Rodriguez

Interpreting the behaviour of granular material and simulating the gravity flow are complex processes in cave mining methods. In this paper, a new Cellular Automata based code – FlowSim – is used as a flexible tool to simulate the gravity flow and subsidence zone in block caving mines. The simulation results of the gravity flow model in a real scaled mine as well as a scaled physical model are presented in this study. In this research, FlowSim was first calibrated at a mine, based on the information obtained from smart markers. These markers were located in five points of the second block of the Esmeralda sector, at the El Teniente copper mine, Codelco, Chile. The calibration was performed with the objective of reducing the discrepancy between the extraction zone defined by markers in the mine and FlowSim outputs. Regarding the mine data, FlowSim was calibrated with the minimum error of ten per cent between real and simulated results. Then, the calibrated FlowSim model was used to simulate the flow behaviour of a scaled physical model. This model was constructed in the Block Caving Laboratory of the University of Chile to scale down the same block of the Esmeralda sector with the scale of 1:200. The FlowSim outputs show that this software enables the simulation of the gravity flow of the scaled model with less than five per cent discrepancy in grade and dilution entry to the drawpoints. According to the obtained results, this paper recommends FlowSim as an appropriate tool which can improve the design of production level in block caving and can enhance the prediction of the subsidence zone and dilution entry.CITATION:Castro, R, Hekmat, A, Fuentes, M, Armijo, F and Rodriguez, F, 2016. FlowSim – a versatile flow simulation tool to quantify extraction and design alternatives for block caving, in Proceedings Seventh International Conference and Exhibition on Mass Mining (MassMin 2016), pp 645–652 (The Australasian Institute of Mining and Metallurgy: Melbourne).

May 9, 2016

By K. Yoo

Cuprous oxide is one of the oldest antifouling agents and also acts as red pigment in these paints. In printed circuit board manufacturing industries, waste etchant contains a substantial amount of copper ion. In the present study, a process was suggested for recovering cuprous oxides from the waste etchant and optimum conditions were investigated to recover the cuprous oxides. The process consists of two steps: in first step, Cu powder is added into wastewater solution, and cupric ions re-duce into cuprous ions (Cu+Cu2+?2Cu+), where cuprous ions precipitate as cuprous chloride; In second step, cuprous oxide is synthesized by adding NaOH into cuprous chloride solution (2CuCl+2NaOH?Cu2O+NaCl+H2O). Optimum conditions were investigated to recover cuprous oxide in the processes. When copper powder was added into wastewater with copper ions, Cu concentration decreased from 15.6% to 2.6% and ORP decreased from 620 mV to -59.9 mV. This result shows that cupric ions reduced into cuprous ions. XRD data indicated that the precipitate was cuprous chloride powder. Using the cuprous chloride recovered and NaOH solution, cuprous oxide was synthesized. To investigate the optimum condition, various NaOH solutions were added into water with CuCl, and then pH, ORP, Cu concentration, Cu contents in precipitates were analysed. XRD data showed that main component of precipitates was cuprous oxide.

Jan 1, 2014

The recovery by flotation of some complex uranium minerals such as brannerite and davidite is described. Anionic reagents used for flotation of iron and titanium oxides' are suitable. If care is taken, to emulsify the reagents the slime fractions may be satisfactorilytreated.INTRODUCTIONUranium ores are usually treated by direct leaching with acid or alkali according to the nature of the gangue materials. Concentration of the uranium minerals prior to leaching is not commonly practised because of the earthy nature of most uranium minerals and the difficult mineral dressing problem they pose. Some of the harder complex oxides such as davidite and brannerite are amenable to flotation. This is fortunate since they usually require an expensive, strong acid treat~ent to dissolve the uranium. Flotation tests were commenced in 1949 by officers of the South Australian Department of Mines stationed at Adelaide, first in the School of Mines, then in the University of Adelaide and finally in Departmental mineral dressing laboratories at Thebarton. Separation of daviditefrom Radium Hill and Mount Victoria ores, brannerite from Crocker's Well ore, and secondary uranium minerals from Myponga ore was attempted.The development of the flotation reagents to separate the oxides from silica and the silicates is first described, then some of the results obtained are presented as tables.DEVELOPMENT OF FLOTATION REAGENTSThe davidite at Radium Hill is associated with iron and titanium oxides, qu;a,rtz and biotite as replacement deposits in shears. The davidite, rutile,' ilmenite and hematite usually occur in segregations from nut size to masses of several pounds. They are associated as a complexity of...

Jan 1, 1955

We present a novel hybrid algorithm for quantifying the ore grade variability that has central importance in ore reserve estimation. The proposed algorithm has three stages: (1) fuzzy clustering, (2) similarity measure, and (3) grade estimation. The method first considers data clustering, and then uses the clustering information for quantifying the ore grades by means of a cumulative point semimadogram function. The method provides a measure of similarity and gives an indication of the regional heterogeneity. In addition, grade estimations can be obtained at different levels of similarity using a weighting function, which is the standard regional dependence function (SRDF). Keywords: Grade, fuzzy clustering, similarity measure, point madogram, weighting function.

Jan 1, 2008

By R. L. Andrew

The southwest Pacific has produced at least four of the world’s premier porphyry copper-gold deposits, and the current level of exploration is likely to produce even more. An appreciable amount of gold is being produced with this copper, with obvious economic advantages. Gold content, in addition to their large size, makes the southwest Pacific’s porphyrycopper-gold deposits very attractive exploration targets. The recognition of telescoping and overprinting of porphyry systems has produced a greater awareness of the likely surface expressions, in particular the significance of advanced argillic lithocaps in porphyry exploration. The recognition of the spatial and genetic association of porphyry copper and epithermal gold systems (Sillitoe, 1972), as in other parts of the world, has had important implications for exploration in the Asia Pacific region.

Jan 1, 1995

THE following short paper on the Blair Athol coal-field will no doubt have a twofold interest to members from the fact that its main seam, known as the "Big Seam" of a maximum thickness of 91 ft without a band, is unique, being probably the thickestseam of high-grade clean coal yet known, and also because of the interesting problem it presents the colliery engineer-viz., which system of mining is the best to secure the highest economical extraction.Location - Blair Athol is a mining township in Central Queensland, situated at an altitude of about 1100 ft. above sea-level at the end of a branch railway line 74, miles from Emerald, on the Main Central Western line, and 240 miles by rail from Rockhampton.Geology - The coal-measures appear to lie in a shallow basin of about four or five square miles in area, surrounded on all sides by slates and schists, which are overlaid oh three sides by alluvial deposits of up to 150 ft. in thickness, and on the fourth by a thick basalt bed, as yet unproved, some miles beyond which the auriferous slates outcrop. These alluvial deposits have been largely worked in years past and gave high gold returns, the chief diggings being Clermont and Macdonald's Flats in the south, the Springs and Black Ridge in the north-east, and Yankee Creek and others on the west. The surface of the coal-fields may be described as unbroken, but undulating, with gentle southerly dip, the watercourses opening out into wide flats. The absence of creeks or deep gullies accounts for no outcrops being visible on the surface, and the coal-measures...

Jan 1, 1918

By A. L. Anderson, J. T. Rybock

KEECO has developed the Silica Micro Encapsulation (SME) technology for the treatment of acidic, metal-laden waters. Utilizing a silica-based chemical formulation that entails chemisorption and micro-encapsulation of heavy metals in a permanent silica matrix, encapsulated particles settle quickly and are effectively isolated from the surrounding environment, producing a stable sludge that is characteristically non-hazardous. In a number of independently-verified pilot and full-scale applications (including the Bunker Hill Mine, Leviathan Mine, Wheal Jane Mine, and Meldon Quarry), SME has been proven highly effective. The technology has been featured in a number of mining publications and selected for innovative technology awards.

Jan 1, 2000

By C. K. Kocsis

A study was undertaken to evaluate the thermal environment and determine the contributing heat sources within the existing 153 Orebody of Coleman/McCreedy East Mine which would then enable the prediction of the climatic conditions in the mine?s future 170 Orebody. The study entailed continuously monitoring, for a 2-week period, the dry-bulb temperature, humidity and barometric pressure along the existing intake airways from surface down to the 4810 Level and throughout an active mining area on that level. Furthermore, the mining activities and associated equipment that could be responsible for any changes in the temperature and humidity conditions within this mining area were also monitored. These data were then used to develop and validate a climatic simulation of the mine?s mechanized cut and fill mining method. This climatic model was then transposed to the future 5700 Level in the deeper 170 Orebody, to determine the environmental conditions within its production workings and along the main haulage route ascending from that area. Based upon the simulations performed it was shown that the level of ventilation planned for the new orebody should be able to maintain adequate environmental conditions. However, this study did emphasize the importance of the appropriate distribution of airflow in workplaces that used auxiliary ventilation in order to sustain a suitable thermal environment.

Jan 1, 2009

By M E. Taulis, S Hayton, D A. Manhire, J G. Pope

Successful development of coal seam gas (CSG) resources in low-rank coalfields such as the Powder River Basin has raised interest in CSG from low rank coal in New Zealand. Kenham Holdings Limited holds 12 Petroleum Exploration Permits (PEP) covering some of New ZealandÆs low-rank coal and lignite resources and has engaged CRL Energy Limited to assist in the systematic evaluation of the CSG potential of the permits. To date, exploration results from seven New Zealand coalfields reflect differences in coal type, rank, depositional environment and depth of burial between coalfields. Several of the explored coalfields are considered prospective for CSG. One of the most advanced Kenham exploration programmes is in the Hawkdun Coalfield, Central Otago.   The Hawkdun Coalfield contains a single, thick lignite seam with properties that are similar to the Powder River Basin. Preliminary results indicate the Hawkdun Coalfield is prospective for CSG with the potential to contain between 25 and 60 PJ of gas; enough to supply a 30MW power station for ten to 25 years. Further drilling is planned to investigate the economic viability of the Hawkdun Coalfield. The in situ permeability of the lignite, the amount and availability of free gas, gas saturation at depth and market opportunities will determine its economic viability. If initial pumping and production results in the planned exploration programme are promising, the Hawkdun Coalfield will be further developed with additional production drillholes to form a trial production pod.

Jan 1, 2004

By Hamid Butt

Information Technology ??Advanced Information Technology is dramatically changing information flow within organizations. This enables employees to have information at their fingertips to make informed and prompt decisions. ??Real-time information allows timely analysis, which dramatically reduces cycle times, making organizations faster and more flexible. Business Challenges ??Continual growth of mining and Mine mobile fleet.??Increasing maintenance costs. ??Difficult to identify and troubleshoot equipment problems while equipment is operating. ??New equipment is increasing in complexity and cost. Therefore, each failure results in a greater impact to production and cost. ??Troubleshooting practice is reactive. ??Protect and optimize the use of mining assets to realize maximum business value. ??Maintenance and Operating information is not easily accessible ?no near real-time system that provides complete information.

May 1, 2006

By Dennis W. Boehm

The building boom of the late 1970's and early 1980's has all but used up most of the better sites across the more populated metropolitan areas of the United States. This means that current buildings and other types of structures are being founded on more marginal sites. The use of marginal sites has placed ever-increasing quality control on the installation of the deep foundation systems utilized for these sites. Several remedial techniques are available for the repair of the deep foundation systems. These include minipiles, compaction grouting and jet grouting. Eight case histories are cited where these methods have been utilized to repair deep foundations.

Jan 1, 1999

By F. Lanaro, K. Röshoff, R. Christiansson, L. Jing

This paper presents the results of a project for developing a methodology for empirically determining some of the mechanical properties of the rock mass at the Äspö Hard Rock Laboratory, Southern Sweden. Using the equations available in the literature, the deformation modulus, friction angle, cohesion and unconfined compressive strength of the rock mass were estimated. A comparison of the results using different classification methods (Q, RMR, GSI, RMi, Ramamurthy’s) was made to estimate the range of variations in the mechanical properties with the considerations of: i) the quality/quantity of the geological data; ii) the technique for partitioning of the rock mass into homogeneous domains; iii) the sensitivity and subjectivity of the empirical methods; and iv) the need for validating the empirical methods against a test case. Cet article présente les résultats d’un projet visant à établir une méthodologie, pour déterminer, de façon empirique, les propriétés mécaniques de la masse rocheuse. En utilisant les corrélations disponibles dans la littérature, quelques-unes des propriétés de la masse rocheuse ont pu être déterminées (module de déformation, angle de friction, cohésion, force de compression illimitée). Une comparaison des résultats obtenus par différentes méthodes (Q, RMR, GSI, RMi, de Ramamurthy) a permis d’établir une échelle de variations des propriétés mécaniques et de formuler une série de recommandations concernant : i) la qualité/quantité des données géologiques ; ii) la technique de partition de la masse rocheuse dans des domaines homogènes ; iii) la sensibilité et la subjectivité des méthodes empiriques ; iv) la nécessité de valider les méthodes empiriques à l’aide de nouvelles études de cas. Dieses Paper präsentiert die Ergebnisse eines Projekts mit dem Ziel, eine Methodik für die empirische Festhellung von mechanischen Eigenschaften im Gesteinmassiv zu etablieren. Durch Verwendung der in der Literatur zugänglichen Korrelationen, wurden einige Eigenschaften des Gesteinmassivs festgestellt (Entstellungsmodul, Reibungswinkel, Kohäsion, unbeschränkte Kompressionsstärke). Ein Vergleich der Ergebnisse unterschiedlicher Methoden (Q, RMR, GSI, RMi, Ramamurthy’s) wurde durchgeführt und dies erlaubte die Feststellung der Variationsskala von den mechanischen Eigenschaften, sowie eine Reihe Empfehlungen für: i) Qualität/Quantität der geologischen Dateien; ii) die Technik für Teilung des Gesteinmassivs in homogene Domäne; iii)die Empfindlichkeit und Subjektivität der empirischen Methoden; iv) das Bedarf die empirische Methoden gegen neue Fallgeschichten zu validieren.

Jan 1, 2003