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By J. W. Gregg, P. M. Dranchuk, D. L. Flock

"From preliminary investigations it has been observed that although evaporation losses may be estimated by comparing single values of certain physical properties of crude oils and their evaporation residues, such techniques possess little accuracy unless both the evaporation process and the variation of the property as a function of the process are completely known. The accuracy of estimation may be increased somewhat through the comparison of property mid-per-cent curves. Further increases in accuracy are possible if bottoms yield •curves rather than mid-percent curves are used. The use of both the mid-percent and bottoms yield curves however involves a prohibitive amount of effort in most cases. Examinations of distillation bottoms from Hempel type distillations carried to end points just short of the cracking point have indicated that these bottoms are not appreciably affected by the evaporation process. It was further observed that bottoms of identical API gravity, obtained from a crude oil and its evaporation residues behave as if they were pure components which were unaffected by evaporation. Based on these observations Hempel distillation bottoms of equal API gravity were obtained for a crude oil and its various evaporation residues from API gravity bottoms yield curves. The volume percent of these bottoms in the crude oil and its residues were used to calculate the evaporation losses suffered by the crude in order to yield the various residues. The results indicate that, although further refinements in technique are required, it is possible to calculate evaporation losses with an accept-able degree of accuracy through the use of this method."

Jan 1, 1960

By B P. Scott

Podsol soil horizons developed on Pleistocene glacial sediments overlying the Coronation Mine orebody were analyzed for copper and zinc spectro-photometrically, using biquinoline-isoamyl alcohol and dithizone carbon tetrachloride reagents. Copper and zinc are concentrated in the A. and C horizons, whereas the A1, A2 and B horizons are leached. Of economic significance is the fact that the C horizon contains a copper anomaly, in excess of 100 times back-ground, directly over the orebody. Due to the erratic distribution of high copper concentrations in the Ao horizon with respect to the orebody, that horizon is not considered as a reliable prospecting datum. U NDER certain conditions, metallic ore deposits are accompanied by primary halos of trace elements in unweathered rock surrounding the orebodies or by secondary halos in weathered rock, alluvium, soil, or vegetation above or near the mineralized zones. Where such halos occur, chemical analysis, as applied to the detection of trace elements, is a valuable prospecting aid, permitting the detection of mineralization of possible economic value.

Jan 1, 1965

By Guangyuan Li

A 3-D block-spring model (BSM) has been developed for simulating the behaviour of jointed rocks. The model uses a discontinuous formulation and an iterative procedure to solve the large displacements in jointed and faulted rock masses. The 3-D BSM has been used to simulate mining excavations in jointed rocks around an open pit and underground settings. The applications have demonstrated that it is a practical tool to solve complicated problems of rock mechanics in civil and mining engineering. This model has recently been modified to incorporate complex geological conditions, such as underground water flow (seepage), unstable blocks and the time-dependent behavior of backfill materials. To demonstrate the capability of the 3-D model this paper presents the fundamentals of the 3- D BSM and its application for open-pit mining. A complete computer package BSM3D has been developed based on the 3-D block-spring model. The package consists of a solving engine for numerical analysis and a Windows based processor for mesh generation and results display. The multi-functioned pre-processor provides tools and menus to help users setting up models easily and conveniently. The fully featured post-processor allows users to view the results in different windows and orientations. The graphical results include contours, vectors, animation of rock movement, and the failure state of the rock structures.

May 1, 2001

By Doris Stüben, Geoffrey P. Glasby, Akira Usui, Jörg-Detlef Eckhardt, Bruce W. Mountain, Zsolt Berner

"Abstract - Twenty-seven marine Mn and Fe deposits chosen for their diverse origins have been analyzed for five platinum-group elements (PGE). The PGE display their highest concentrations in hydrogenous Mn crusts and nodules, lesser concentrations in diagenetic nodules and two to three orders of magnitude lower concentrations in hydrothermal Mn and Fe crusts. This difference of behavior reflects the well-known fractionation of Mn and Fe from the other transition elements, rare earth elements (REE) and PGE in hydrothermal Mn and Fe crusts. Pt, Ru, Rh, and Ir show a close geochemical coherence in these deposits and are differentiated from Pd which shows a negative anomaly with respect to the other PGE in hydrogenous and diagenetic Mn deposits. Pd is less depleted than the other PGE and the Pd anomaly much less pronounced in the hydrothermal Mn and Fe crusts relative to the hydrogenous and diagenetic Mn deposits.Stability field diagrams show no evidence for the oxidation of Pt to the tetravalent state in seawater as suggested by some authors. Rather, Pt appears to be present in seawater as Pt(OH)2 0. Adsorption of Pt(OH)2 0 onto the surface of Mn and Fe oxyhydroxide minerals may explain the enrichment of Pt in marine Mn deposits. However, Pt metal is the thermodynamically stable solid phase of Pt under seawater conditions and reduction of Pt(OH)2 0 to Pt metal, particularly in the vicinity of the oxygen minimum zone, is possible, although the high Ce/La ratios of the Co-rich Mn crusts do not support this hypothesis. Pt, Ru, Rh, and Ir display their maximum concentrations in the Corich Mn crusts. This may reflect, among other things, the low growth rates of these deposits. The stability field diagram of Pd shows that Pd is undersaturated in seawater and occurs in seawater dominantly as PdCl4 2- and anionic mixed-hydroxide-chloride complexes. This would explain the anomalous position of Pd among the PGE with respect to its uptake into marine Mn deposits. A study of inter-element associations indicates that the incorporation of the PGE from meteoritic dust plays only a minor role in the uptake of these elements into marine Mn deposits. The PGE remain the most poorly studied group of elements in marine Mn deposits. The data presented here emphasize the need for the establishment of a more comprehensive database of the PGE in marine Mn deposits in order to understand more fully their uptake into marine Mn deposits and their pathways through the oceans."

Jan 1, 1999

By Rakesh Kumar, Rajabrahma K., A. K. Verma, V. Mukesh

"In this study, laboratory investigation as well as numerical investigation is carried out to ascertain the transition from one mode to another for Semi-circular bend setup. Laboratory investigation is carried by varying the span length (s/2R); crack length (a/R); notch angle (a); and notch thickness (t). The specimen consists of cement, sand and water mixture in a ratio of 1:1:0.5 by weight and are prepared as per the ISRM standards (2014). Tests are conducted by a servo controlled universal testing machine at a strain rate of 0.2 mm/ min. The results are collected in terms of failure load, crack mouth opening displacement (CMOD) and images of crack initiation and propagation.Image analysis of laboratory tested samples shows that crack initiates at the notch tip when the notch inclination angle is 0°. As the notch angle increases (i.e. 30° and 60°) the fracture begins to initiate behind the notch tip. The direction of crack propagation in front and back side of the sample is same for notch inclination angle is 0° whereas it differs more and more as crack inclination increases. The transition represents the change in mode of failure from mode I (0°), mode II (30°) and mixed mode I/II fracture (60°).Finite element method used to find the transition based on MTS failure criterion. The inclination of notch is varied like 40, 42, 44, 45, and 50 deg and FEM analysis shows that the transition from mode-I to Mode-II take place at 49 deg. The same procedure can be extended to find the transition from mode-II to mode-III."

Jan 1, 2015

By R. J. A. Fricker

IT is the purpose of this essay to give a reasonably complete description of shaft sinking under a rock pentice in a small Northern Ontario gold property. Hallnor is in many ways an exceptional mine, but the sinking operations here described are but typical examples of the excellent practice for which Canadian mines and mining engineers are justly famous the world over. The worth of the subject lies, therefore, nor in its originality, but in its soundness; not in the spectacular, but in the economical and safe. Attention is particularly drawn to the excellent safety record and to the exceptionally low overall sinking cost. INTRODUCTION Prior to April, 1939, the Hallnor No. 1 shaft had been sunk vertically to a depth of 997 feet below the surface. It is a three-compartment shaft, 19 ft. 10 in. by 7ft. 7 in. outside the timbers (see Figure 1).

Jan 1, 1941

By Z. Trojanová

Mg micropowders generated by gas atomisation of a magnesium melt with argon were mixed and ball milled with ceramic nanoparticles prepared by laser-induced gas phase reaction. The materials were then hot extruded. Specimens were deformed in tensile as well as compression tests at temperatures between 20 and 300 °C at a constant initial strain rate. The flow stress is significantly influenced by the test temperature. The yield stress decreases with temperature. This decrease and the flat character of the stressstrain curves at elevated temperatures indicate possible contributions of softening processes. The materials studied exhibit high-damping characteristics. The results are analysed and possible mechanisms are discussed.

Jan 1, 2006

By Matt Manson

Renard?1-10 kimberlite pipes and ?Lynx-Hibou?kimberlite dyke system within ?Foxtrot?property 50/50 JV with SOQUEM, Stornoway operator 2001: Discovery of the Renard kimberlite pipes 2003: Discovery of the Lynx-Hibou kimberlite dykes 2006-2007: Bulk sample program 2008: First 43-101 Resource and Preliminary Assessment 2009/2010: Updated 43-101 Resource

May 1, 2010

By C. Morlot, C. Auvray, E. Fourreau, J. Talandier

"During the excavation of underground galleries in a rock mass, reorganisation of the stress field around the site results in damage to the surrounding material. In the framework of research undertaken at the ANDRA underground laboratory in France, galleries have been excavated in a Callovo-Oxfordian argillite formation. The damage has manifest as a number of fracture systems in the adjacent rock. Observations have shown that fractures generated during excavation and storage exploitation are able to self-seal during re-saturation of the site in the post-closure stage. Although indirect evidence for argillite self-sealing has previously been reported, from experiments performed both in situ and on samples, no direct observations of self-sealing have yet been made.For the present study, we performed a range of self-sealing experiments using a newly-developed triaxial compression cell placed within a nano-CT scanner with a 10 µm resolution. The body of the compression cell is X-ray transparent, allowing sample healing to be monitored directly. The samples contained an artificial fracture that had been generated in the laboratory, into which a fluid was injected. The fractures were orientated either perpendicular or parallel to the plane of anisotropy of the material. Our initial results demonstrate that when fluid is injected perpendicular to the plane of anisotropy, the flow-rate has no apparent influence on the kinetics of fracture closure. Permeability varies significantly, from 2.10-14 to 2.10-18 m2 over 116 hours. Post-test observations of the fracture lips show swelling that appears to be orientated perpendicular to the fracture plane and therefore parallel to the plane of anisotropy. Initial results for an injection parallel to the plane of anisotropy suggest that, in this case, the rate of flow affects the kinetics of fracture closure. For a flow-rate of 0.25 ml/min, closure begins after around one minute. In contrast, for a rate of 0.05 ml/min, it is necessary to wait several minutes before partial sealing of the zone is observed. The reduction in permeability is again significant, from 2.10-15 to 4.10-18 m2 over 96 hours. After completion of the test, swelling was observed in elongated zones that lie parallel to the fracture plane and therefore to the plane of anisotropy."

Jan 1, 2015

By J. N. Van der Merwe, M. Mathey

"We present an analysis of the mechanical properties of coal specimens from various coalfields and seams in South Africa. Our database comprises of 1800 test results from uniaxial and triaxial compression tests, as well as indirect tensile strength tests, which we collected from the various mining houses and research agencies in the country. We inspected the database for possible errors and present a brief description of the verification procedure in the paper.In the analysis, we reveal that the collected samples of strength and elastic properties of South African coals can be represented by single lognormal or normal distributions with only few outliers. This finding indicates that the samples realistically approximate the population of mechanical coal properties in the country and may suggest that the properties are randomly distributed. Significant coalfield- or seamspecific trends for the mechanical properties of coal are not clearly discernible from our data.Typical coefficients of variation for the individual mechanical properties range between 25-50 % on a country-wide and seam-specific level of analysis. Average uniaxial compressive strength values, however, are closely clustered for all seams. A comparison with data available from international coal strength studies show the distinct difference between South African coals and seams in countries of the Northern Hemisphere, where differences in the average coal seam strength are more pronounced.We observe that the number of specimens whose failure mode is influenced by the presence of natural discontinuities reduces drastically with the application of very small confining pressures to the specimens. Further, the strength-reducing influence of discontinuities diminishes with increasing confining pressures."

Jan 1, 2015

By André Chagnon, Michel Malo, Benoît Dubé, Chantal Pelchat

"Abstract- In the southern Gaspé Appalachians, gold mineralization is spatially associated with the Acadian dextral strike-slip Grand Pabos-Restigouche fault system. Two different structurally-controlled gold prospects, the Lac Arsenault and the Saint-André-de-Ristigouche, are described to unravel the genesis of gold mineralization in this part of the Canadian Appalachians.At the Lac Arsenault gold prospect, gold mineralization consists of Au-As-Pb-Zn-Cu-(Ag) polymetallic fault-filled quartz veins with laminated textures emplaced in brittle-ductile sinistral X shear fractures. Mineralized veins are hosted by Middle Ordovician graywacke of the Arsenault Formation, belonging to the Dunnage Zone, the Early Paleozoic oceanic domain of the Appalachians. Terrigeneous rocks of the Arsenault are regionally metamorphosed at the lower greenshist facies and the mineralized veins are included in a zone of Fe-carbonate alteration.The Sb-Au-As mineralization of the Saint-André-de-Ristigouche gold prospect, in the southwestern Gaspé area, comprises extension veins in the extension direction emplaced in brittle conditions. Mineralized veins are hosted by calcilutite and laminated silty and argillaceous limestone of the Early Silurian part of the White Head Formation, which belongs to the Gaspé Belt, the Middle Paleozoic successor basin in the Gaspé Appalachians. Metamorphic grade of the White Head Formation in the southwestern Gaspé area is very low, but the gold mineralization is included in a zone of hydrothermal propylitic alteration which includes two Cu-skarn mineral occurrences. The Lac Arsenault gold prospect has many characteristics of "greenstone-hosted quartz-carbonate vein" deposits whereas the southwestern Gaspé area, which includes the Saint-André-de- Ristigouche gold prospect, shows affinities with the geological setting of sediment-hosted gold deposits (Carlin-like deposits). The two gold prospects are controlled by the Grand Pabos- Restigouche fault system but they were not emplaced at the same level in the crust. Acadian strikeslip fauting played a major role in their respective genesis in providing channelways for ore-bearing fluids. The recognition of the analogy of the geological setting of the southwestern Gaspé area with that of Carlin-like mineralization gives new ideas for exploration in the area and elsewhere in the Appalachians.Résumé - Dans le sud des Appalaches de la Gaspésie, on trouve des minéralisations aurifères spatialement associées au système de failles de coulissage dextre acadien de Grand Pabos-Restigouche. Deux indices très différents, Lac Arsenault et Saint-André-de-Ristigouche, sont décrits pour évaluer la genèse des minéralisations aurifères à contrôle structural de cette partie des Appalaches canadiennes. Au Lac Arsenault, la minéralisation aurifère comprend des veines polymétalliques à Au-As-Pb- Zn-Cu-(Ag) en remplissage de failles. Ces veines à texture laminaire se retrouvent dans des zones de cisaillement fragiles-ductiles senestres de type X. Les veines minéralisées sont encaissées dans les grauwackes d’âge Ordovicien moyen de la Formation d’Arsenault appartenant à la zone de Dunnage, le domaine océanique du Paléozoïque précoce des Appalaches canadiennes. Les roches terrigènes de l’Arsenault sont métamorphisées régionalement au faciès inférieur des schistes verts et les veines aurifères sont dans de larges zones d’altération dolomitique (Fe-carbonate).Dans le sud-ouest de la Gaspésie, la minéralisation à Sb-Au-As de Saint-André-de-Ristigouche est dans des veines d’extension comprises dans la direction d’extension et mises en place dans des conditions de déformation fragile. Les veines minéralisées sont encaissées dans les calcaires argileux et les calcilutites de la partie silurienne de la Formation de White Head qui appartient à la ceinture de Gaspé, le bassin successeur du Paléozoïque moyen des Appalaches de la Gaspésie. Le degré métamorphique des roches du White Head est très bas, mais"

Jan 1, 1998

By Karina Forster

Open stope design depends on the ore body geometry, loading conditions and rock mass properties to estimate stope dilution and ground support requirements. Rock mass conditions for design primarily rely upon estimates of well established rock classification systems. Many sources of data exist for obtaining estimates for these rock mass classification values which include core logging, geotechnical mapping, geological mapping as well as linking one classification system to another through the use of empirically derived equations. The extent of mapping coverage can also vary significantly based on the data collection technique. This paper proposes an approach where individual components of rock mass classification systems are collected by the different available data collection techniques. Data from different rock types are also considered separately based on their alteration characteristics and general observation products. Data from the Cameco Corporation Eagle Point Mine is presented and an approach is outlined for obtaining average representative classification values for stope hanging wall characterization. The effectiveness of this approach is demonstrated through the analysis of a data base of hanging wall dilution information.

Jun 1, 2012

By Alain Simard, Sylvain Lacroix, Louis-Martin Dubé, Pierre Pilote

"The Harricana-Turgeon belt (HTB) is a poorly known volcano sedimentary belt in the NW part of the Abitibi Sub-province; it includes the Matagami, Joutel, Brouillan and Casa-Berardi mining districts. The HTB is dominated by volcanic rocks, which covers 65% of its surface area, followed by sedimentary (18%) and plutonic (17%) rocks. It is also transected by numerous deformation zones located either at the contacts of volcano-sedimentary units and granitoid bodies or cross-cutting them. A preliminary geological synthesis shows that mineral deposits are associated with certain regional geologic elements.The volcano-sedimentary units are grouped here into twelve band-shaped lithotectonic domains, most of which extend for more than 150 km E-Win the HTB. Each domain is defined by lithologies and facies associations, and gradiometric and electromagnetic signatures.Eight domains are composed of basaltic or basaltic to komatiitic associations, interlayered with thin pelagic sediments, representing sub-marine lava plains. Two domains are composed of basaltic to rhyolitic associations that are interpreted as volcanic arcs formed by one or several central volcanic complexes.The sedimentary rocks are grouped into two lithotectonic domains. Each is composed of rhythmic sequences of turbiditic sandstone- siltstone-shale, Algoma-type banded iron formations and conglomerates bearing plutonic and volcanic pebbles. These three facies come partly from mass flow at the bottom of a slope in a moderately deep marine environment. In each domain, a conglomerate sandstone- siltstone sequence, containing poly genetic pebbles of local provenance, is similar to Timiskaming-type alluvial deposits.The nineteen granitoids, found within the HTB and at its border, belong to numerous petrographic suites, and have been grouped into four structural families: pre-tectonic, pre- to early-tectonic, syn- to late-tectonic, and late- to post- tectonic. The pre- to early-tectonic plutons are presumed to be sub-volcanic and are generaly associated with the volcanism of central complexes.The HTB mineral resources consist essentially of polymetallic (Cu-Zn-Ag-Au) and gold (Au-Ag) deposits. The polymetallic deposits are located exclusively in the two lithotectonic domains composed of basaltic to rhyolitic associations (Matagami-Brouillan and Joutel Raymond). All gold deposits are associated with deformation zones superimposed on lithotectonic domain contacts and highlighted by graphitic units. Most of the deposits are hosted in the Casa-Berardi and Douay deformationzones, located at the contact of the Cartwright basaltic to komatiitic domain and the Taibi sedimentary domain"

Jan 1, 1990

To create a successful growth oriented diamond company that succeeds in the practical business of mining and selling rough diamonds, and which pursues an aggressive exploration strategy to seek and develop worldclass diamond mining opportunities in a market that has become increasingly under-supplied.

May 1, 2008

By D. A. Bordin, C. J. Newman, R. J. St. Eloi

"The requirements for a metallurgical acid plant treating smelter gases are both unique and demanding in terms of sulphur dioxide treatment and emission control. Since start up in 1981, the copper smelter at the Kidd Creek Division of Falconbridge Limited has undergone several major expansions. The expansion and modification of the acid plant has been an integral part of this process. Both production demands and government regulations dictate that this metallurgical acid plant be unique in terms of operating flexibility. The variable capacity to treat a wide range of sulphur dioxide concentrations, and the operating flexibility to control emissions are the topics of this paper.INTRODUCTIONThe Kidd Creek Division of Falconbridge Limitied is a base metal mining and metallurgical complex located in Timmins, Ontario. The discovery of the original copper-zinc-silver orebody was announced in April, 1964. Mining operations began in 1966 with a 9000 tonne per day concentrator coming on stream in November of that year. In April 1972, a 108 000 tonne per year zinc plant was commissioned. Over the years the facilities have been expanded, such that the concentrator now has the capacity to process 13 000 tonnes of ore per day . To expand zinc production, the world's second installation of the Cominco/Sherritt pressure leaching facility was completed in 1983 to bring total zinc production capacity to 125 000 tonnes per year. In 1973, serious planning for a smelter operation began. In early 1975, after studying both continuous smelting and flash smelting processes, a decision was made to proceed with the technology offered by Mitsubishi Metal Corporation of Japan. The Mitsubishi Continuous Smelting Process was to be used for the smelter and the Onahama No.3 tankhouse technology for the copper refinery.The smelter, which uses the Mitsubishi Continuous Smelting Process for the continuous production of blister copper from concentrate, went on line in June 1981. It has been expanded from its original capacity of 60 000 tonnes to 100 000 tonnes per year of copper.From the very early design stages for the metallurgical complex, the company had adopted a policy of constructing and operating modern plants which would meet existing and anticipated environmental standards. With this in mind, the decision was made to utilize the proven technology of fixing sulphur dioxide emissions, in the form of sulphuric acid. A 636 tonne per day single absorption contact acid plant was built to serve the zinc plant in 1972. In 1981, an 883 tonne per day double absorption contact plant was built to serve the needs of the copper smelter. The copper smelter acid plant has since been expanded to a design capacity of 1692 tonnes per day and it is the main focus of this paper."

Jan 1, 1989

By N. Golchinfar

Tunnels in deep mines are subjected to high stresses. Fracture and failure of the rock mass around an opening can occur when mining-induced stresses are high. In burst-prone grounds, mining-induced seismicity can cause additional dynamic loading which can further increase the stress around the tunnels. When the dynamic stress reaches the rock mass strength, fracturing can occur and rockburst may happen (depending on loading stiffness around the failed rock mass). Rock support installed in the tunnel must be capable of dissipating dynamic energy and holding the failed rocks. Hence, it is important to estimate the depth of failure for rock support design. This paper focuses on how to model depth of failure under dynamic loading. In the modeling, two scenarios of rock failure are considered. In the first scenario, rock failure occurs under static loading and subsequent dynamic loading further increases the depth of failure. In the second scenario, no failure occurs under static loading but in the subsequent dynamic loading, failure around the tunnel is created.

Aug 1, 2013

Agenda ?The Context ?The Challenge ?The Solution ?Benefits and lessons learnt from pilots ?Next Steps The Context ?Facilitate management decision making process by supporting the development of value/risk based business cases. ?Large scale investments by extractive industries are expected tobring broad-based benefits to local communities (e.g.: health, education, jobs, infrastructure) ?Investors continue to expect the demonstration of social performance?Specific interventions bring direct value to companies (e.g. skills development) ?Social Investments are key to protecting a company?s license to operate ?Quantifying the value of these investments and planning accordingly, however, has long posed a challenge for the extractive industries and community development practitioners

May 1, 2011

By B. R. Boardman

Project Environmental Approval is a multi-faceted issue. From a mining perspective, it is a costly item because of avoidable time delay. The government perspective is that the approvals are a necessary part of meeting departmental requirements to ensure that the wellbeing of other uses of the environment is maintained. This paper outlines some of the problems inherent in the environmental approvals process and makes recommendations to both the proponent and government about improving the efficiency of the process.

Jan 1, 1978

By K. Thuro, H. Käsling, F. Menschik

"With increasing data volume, due to enhancing requirements for ground investigation programs for large construction projects, the demand for more efficient filing systems is more and more growing. Depending on the project we also have to use flexible systems to cope with varying data out of different lab and field tests.The chair for Engineering Geology at TUM is developing a web-based database solution to handle all project relevant data in a more appropriate way. We aim to optimize our data management to achieve a fast and easy way of collecting, documenting and analyzing our gained data. The second objective is to provide an easy access to our data for project partners across broadly distributed locations.This Database system consists of a PHP web interface and a MySQL database core. The current setup allows an online access via Internet (www). We are able to grant and constrain access to all data or only arrays of data with our user management system to guarantee the safety of project data and respect all rights and proprietorship. The database system is of modular design and consists of the following three base modules: module of general project data, module of laboratory data and user management module. At the current stage we are able to save and work with all usually generated specific values from unconfined compressive strength tests, brazilian tensile strength tests, point load tests, CERCHAR and LCPC abrasivity tests and ultrasonic tests. The user is able to perform a simple statistical analysis within our database (e.g. average calculation of one sample) and export data as csv or xls files for further analysis.For specific questions within projects we are able to deploy and integrate further modules in our database system. At this moment, we are developing an add on to use this database for different drill test analyses. One of the tools correlates drilling performance and drill head wear measured in the field with rock mechanical properties, and extrapolates the data to estimate the performance and wear in new projects. Today we are managing 90 projects with 550 samples and almost 1350 lab tests with the base module.In our contribution we aim to demonstrate an efficient way of data structuring using a relational database for laboratory and field testing data."

Jan 1, 2015

By D. Tao

Froth flotation is widely used in the coal industry to clean -28 mesh or -100 mesh fine coal. A successful recovery of particles by flotation depends on efficient particle-bubble collision and attachment with minimal subsequent particle detachment from bubble. Flotation is effective in a narrow size range outside which the flotation efficiency drops sharply. A fundamental analysis has shown that use of picobubbles can significantly improve the flotation recovery of particles by increasing the probability of collision and attachment and reducing the probability of detachment. A specially designed column with a picobubble generator has been developed for enhanced recovery of fine coal particles. Picobubbles were produced based on the hydrodynamic cavitation principle. Experimental results with one metallurgical coal and one steam coal have shown that the use of picobubbles in a 2" column flotation increased fine coal recovery by 10-30%, depending on the feed rate, collector dosage, and other flotation conditions. Picobubbles also acted as a secondary collector and reduced the collector dosage by one third to one half.

Jan 1, 2006