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By Mengmeng Gai

This paper introduces a model-based automatic object recognition and registration framework to assist heavy equipment operators in rapidly perceiving 3D working environment at dynamic construction sites. A video camera and a laser scanner were utilized in this study to rapidly recognize and register dynamic target objects in a 3D space by dynamically separating target object?s point cloud data from a background scene for a quick computing process. A smart scan data updating method has been developed which only updates the dynamic target object?s point cloud data while keeping the previously scanned static work environments. Extracted target areas containing 3D point clouds were orthographically projected into a series of 2D planes with a rotation center located in the target?s vertical-middle line. Prepared 2D templates were compared to these 2D planes by extracting SURF features. Point cloud bundles of the target were recognized, and followed by the prepared CAD model?s registration to the templates. The field experimental results show that the proposed rapid workspace modeling method can significantly improve heavy construction equipment operations and automated equipment control by rapidly modeling dynamic target objects in a 3D view.

Aug 1, 2013

By T. J. Fee

Introduction The International Nickel Company have been pioneers in mine rescue work in Ontario. Following the fire in the Hollinger mine in the spring of 1928, the Company purchased ten self-contained oxygen breathing outfits, ten all-service gas masks, an oxygen high-pressure pump, life line, inhalator, ten cap-lamps with batteries, and a complete stock of spare and accessory parts. An instructor from the U.S. Bureau of Mines, Pittsburgh, came to the Creighton mine for one week and trained twenty men in the use and limitations of all equipment. Monthly training courses were commenced in the fall, and have continued to the present time. Of the original twenty men trained, ten are still on the Creighton mine rescue teams. In the meantime, and as an aftermath of the Hollinger fire, the Work-men's Compensation Board of Ontario and the Ontario Department of Mines established a central mine rescue station at Timmins. This was completed in the spring of 1930. It was then decided, in view of the great expansion in mine development in the Sudbury district, to build and equip a similar station to serve all the mines there, namely, Creighton, Frood, Garson, Falconbridge, Sudbury Basin, and Errington. An extensive survey was made and a central location selected opposite the Frood mine. The International Nickel Company donated a site, and the station was completed in the fall of 1930. The station is a two-storey brick building, 27 ft. by 47 ft., with a large garage adjoining it. The ground floor is used for equipment and for training the crews. On the second floor are living quarters for the superintendent and his family. The garage houses a closed truck, in which all necessary equipment can be taken to any desired point for training purposes or for actual mine rescue work, if and when necessary. The garage is also used as a gas room, where the men are trained in an irrespirable atmosphere. A gas-tight observation window between it and the training room enables the superintendent to see and direct the men undergoing training, weight exercisers and other devices being used.

Jan 1, 1935

By R. D. Brown

"Taxation tends to be a depressing subject. Taxes are unfair, taxes are too high and, above all, taxes are too complicated.In a recent address to the Canadian Tax Foundation, the author discussed in a rather more lighthearted way the possible causes of the complexity of the present Canadian taxation system. In order to provide an element of relief in this series of articles on taxation matters, extracts from these remarks are quoted below :"

Jan 1, 1976

By M. Staite

This paper analyzed the feasibility of converting a 5kW natural gas SOFC power generator system designed to operate on natural gas to be fuelled by methanol. The analysis included laboratory methanol fuel processing experimentation, methanol reformate SOFC cell testing, and SOFC system mass and energy balance modelling. Methanol fuel processing experimentation indicated that theoretical reformate compositions can be achieved for high temperature (600-900°C) methanol steam reforming. A 6% open circuit voltage decrease and a 10% peak power current density decrease between cell operation on humidified hydrogen and methanol reformate was observed. SOFC system mass and energy balance modelling indicated that a natural gas SOFC system can be converted to operate on methanol fuel with minimal (1%) efficiency impacts, however the systems' thermal integration can be impacted.

Jan 1, 2005

By A. Klingberg, M. Svensson, N. Smolko Schwarzmayr

"Removal of silicates and carbonates from sedimentary phosphate ores by the use of new synthetic collector/formulations was investigated in a comparative study with traditionally used collector systems as references. In the direct carbonate flotation the new formulations showed higher efficiency, contributed to an improved balance of P2O5 recovery and P2O5 enrichment in the recovered material. Efficiency of the new formulations containing synthetic surfactants was 1.5–2 times better than potassium salt of fatty acid sulfonate based formulations that are traditionally used for that purpose. The new formulations also provided up to 7% increase in P2O5 recovery at the same P2O5 grade. The new synthetic collectors for removal of silicates showed extremely good selectivity towards silica bearing minerals. The selectivity factor for the flotation tests when new formulations were used was 32–52 and for the flotation tests with the traditional collectors: 20–32. The ratio between distribution of an amount of silicates (as SiO2) and distribution of phosphate in the froth (waste) is defined as the selectivity factor. The new formulations provided more than 2% decrease of the amount of SiO2 at the same P2O5 recovery.INTRODUCTIONPopulation growth and decrease of arable land are the main reasons for constant increase of consumption of apatite (phosphate ore) in the fertilization field (Lannefors, Gorochovceva, Klingberg, Lima, & Gustafsson, 2015). Fertilizers play a key role for farmers to produce more with less land. The phosphate component of the fertilizer is vital for producing healthy and large amount of crop. As a result the demand for phosphate rock is growing.The largest producers of phosphate rock are the Unites States, Morocco, Tunisia, China, Russia, and Brazil. The term “phosphate ore” includes all phosphate-bearing minerals and rocks, but only two of them are of industrial interest: apatite (igneous origin) and sedimentary phosphate (Peres, Araujo, El-Shall, Zhang, & Abdel-Khalek, 2007). The majority of the world’s phosphate deposits are of the sedimentary type. There are two different types of sedimentary phosphates: siliceous and carbonaceous which are categorized based on gangue minerals (such as quartz, carbonates, mica, and clay)."

Jan 1, 2016

By P. Wanjara, M. Xiao

During fusion welding of aluminium alloys, the avoidance of defects (such as porosity, oxides, hot cracking, undercutting) as well as the ability to optimize the microstructure-property characteristics in the assembly are critical for the stringent manufacturing specifications in the aerospace industry. In this work, aluminium alloy (AA) 2024 was electron beam welded autogenously as part of a study to determine the influence of parametric conditions on the characteristics of the heat affected and fusion zones to obtain optimal welding conditions. In particular the evolution in the weld geometry, microstructure and mechanical properties were examined as function of the processing conditions, including beam current, beam focus, beam oscillation, linear heat input and welding speed. For optimized parametric conditions, microstructural examination of the joints revealed narrow fusion and heat-affected zones comprising of dendritic structures without the occurrence of defects that enabled a maximized joint efficiency.

Jan 1, 2006

By J. D. Bosman, L. J. Gardner

"The Bushveld Complex is a large layered igneous intrusion, located in the northern parts of the Republic of South Africa. The complex hosts the largest known reserves of Platinum Group Metals in the world. On the western limb of the complex, mining of the Merensky economic horizon and UG2 chromitite layer has been conducted for many years by several mining companies, including Impala Platinum Limited. Over the past decade, Impala has planned a new generation of greenfield vertical shafts, commencing with comprehensive geological and geotechnical studies. As part of the geotechnical studies, numerous tests have been conducted to quantify the mechanical properties of the various near-reef rock types. These tests include point load tests conducted in the field, as well as uni-axial compressive strength, triaxial compressive strength, and Brazilian disc tensile strength tests conducted in specialist laboratories. The authors have compiled an extensive database containing a large number of tests for different rock types, ranging from felsic Anorthosite to mafic Pegmatoid. The database was analysed to quantify the mechanical properties and values for Mohr Coulomb and Hoek Brown failure criteria for each rock type typically exposed by mining. The paper will provide a data set of rock mechanical properties typically used in numerical modelling and other design processes. Using the significant number of tests available, data describing the variability of the various parameters will be included."

Jan 1, 2015

By T. T. Chen

The iron- and elemental sulphur-rich residues generated during batch and continuous pressure oxidative leaching of Inco Limited's Voisey's Bay nickel sulphide concentrate at 150°C in sulphate-chloride media have been characterized by X-ray diffraction analysis and scanning electron microscopy. The residues produced during the continuous leaching of the pentlandite- and pyrrhotite-rich concentrate consisted predominantly of hematite and elemental sulphur, with minor amounts of goethite. Although the iron species generated in the batch leaching tests were similar to those formed during continuous leaching, the morphologies of the hematite and goethite particles were significantly different. In addition to the tiny spheroids and bubble-like particles, the hematite and goethite generated during batch leaching occurred as larger "hollow" shell-like particles that contained residual pentlandite or sulphur cores. Although the leach solution from which the iron oxides had precipitated contained 5-15 g/L sodium, sodium jarosite was detected only in trace amounts in a few of the leach residues.

Jan 1, 2006

By D. J. MacDonald

UNDERGROUND development at the Lynn Lake property of Sherritt Gordon Mines, Limited, was begun in 1948 with the sinking of the A shaft in the area of the A orebody. By June, 1949, the shaft was completed to a depth of 1,024 feet. Twelve stations were cut, with the bottom level at 992 feet below the collar. Since completion of the shaft, lateral work has been carried out on the 12th level in order to expose the known orebodies and to provide openings from which deeper exploration could be conducted. Dur¬ing the change-over from sinking to lateral work, preliminary diamond drilling was done from the 12th level station to locate the A? ore-body. Later, drilling was carried out from the 5th and 9th level sta-tions, where, also, the outline of the A orebody was established. As the work progressed on the 12th level, and with the commence-ment of drilling below that level, the geological picture was found to be complicated by numerous faults. Instead of operating two drills it became necessary to use at least four. The original plans had provided air sufficient to drive two headings and to operate two diamond drills. The addition of two more air-driven drills resulted in a serious shortage of power.

Jan 1, 1951

By D. B. Dreisinger, M. R. Tavakoli

Vanadium has been produced from both primary and secondary sources having various compositions. Vanadium pentoxide and vanadium trioxide are the most available and known sources of vanadium oxides. In this paper, an overview of leaching both oxides has been reported. The problem of vanadium pentoxide leaching under acid conditions is the low solubility of the dissolved vanadium. This was investigated and then supplemented with further studies of leaching at mildly basic pH’s as well as under acid reductive leaching conditions (to form vanadium (IV)). Atmospheric oxidative leaching of vanadium trioxide was investigated using oxygen and ferric ion as the oxidant. It was shown that the leaching of vanadium trioxide using oxygen is very slow; however, ferric ion can dramatically increase the kinetics and leach efficiency.

Jan 1, 2014

By J. H. Parliament

"The 15,000-tpd Similkameen open-pit copper mine, 10 miles south of Princeton, B.C., started production during 1972. The two main ore zones are separated by the deep canyon of the Similkameen River, with the Ingerbelle or western deposit being mined first. The location, design and construction of the plant were complicated by the steep terrain and the situation of the orebodies. Mining, utilizing 10-cu.yd electric shovels and 100-ton electric-wheel trucks, is conventional. Closely integrated with the preproduction mining was the construction of a 4-mile section of main highway to bypass the Ingerbelle pit. This entailed a very large fill, placed with mine equipment. Ore is crushed to minus 9 inches, stockpiled and reclaimed for direct delivery to three 32-ft-diameter by 14• ft single-stage autogenous grinding mills, each driven by two 4000-hp motors. Because of the friable ore in the upper part of the mine, 4-inch balls are added, with higher than design throughput attained. Classification is by 91>-inch spiral classifiers and cyclones. The flotation section comprises three parallel lines of ten 400-cu.ft rougher- scavenger cells and a single line of 100-cu.ft cleaner and recleaner cells. Concentrate is transported in end dump, closed trucks to Vancouver for dockside storage prior to shipment to the smelter. Tailings are piped across the canyon on a suspension bridge and through a tunnel to an empoundment area. Water is reclaimed and returned to the concentrator, forming a closed system. Dams are raised with cycloned ands, with the downstream section compacted."

Jan 1, 1973

By Botao Lin, Yan Jin, Hongjuan You, Jingjun Pan, Huiwen Pang, Mian Chen, Sen Chen

"Steam Assisted Gravity Drainage (SAGD) has become the mainstream technology for ultra-heavy oil recovery in Xinjiang oilfield, the success of which depends heavily on shortening of preheating period as well as forming homogeneous and highly permeable zone in land-facies oilsands layer. Towards this aim a special hydraulic fracturing process is required, which is accomplished through controlled water injection to a pair of horizontal wells in order to create homogenously distributed microcracks in the zone between the two wells. The associated mechanical response, however, is unclear for land-facies Karamay oilsands that is loose in texture. In this regard, this research utilizes a triaxial test system on cylindrical specimens extracted from field-collected oilsands cores. Isotropically consolidated drained triaxial compression tests are conducted on both saturated and unsaturated specimens so as to investigate the mechanical response of oilsands at different spots relative to the wellbore. Moreover, acoustic emission and fast pulse-decay permeability are performed to monitor fracture development and permeability evolution. Based on these experimental studies, the mechanism of dilation in oilsands is comprehensively analyzed. The findings reveal distinctive behavior between the saturated and unsaturated specimens as respect to dilation, porosity/volumetric evolution and change of permeability. It is also found that shear bands can be created upon shearing on triaxial specimens, rendering porosity or volumetric strain the factor that is more proper for evaluation of stimulation efficiency in the field.INTRODUCTIONXinjiang oilfield is widely known for its abundant deposit of heavy and ultra-heavy oil that has been estimated to be several hundred million tons. The ultra-heavy oil deposit located in Fengcheng region of Karamay at the northwestern part of the Junggar Basin, Xinjiang, China, has over 360 million tons of resource (Yuan et al. 2013). The resource is deposited in depths from 180 to 450 m and has viscosity over 100, 000 mPa•s at a temperature of 50ºC, bringing technical challenges to recovery activities."

Jan 1, 2015

By L. Chunpongtong

One of the challenges of mine planning is to determine the most cost-effective replacement time for aging equipment. The lifespan of equipment, such as haul trucks and shovels, deployed in mining operations varies due to the nature of the material and ground conditions in which it operates. For engineering economists dealing with aging equipment, the options become an economic trade-off between higher maintenance cost versus the cost of new equipment. The discount rate plays a significant role in this decision; the higher the rate, the longer the economically optimal lifespan. Therefore, the ultimate question is: ?How can the relationship between the discount rate and the economically optimal lifespan be expressed mathematically??

Aug 1, 2013

By Colin E. Dunn

The high mobility of gold within the plant kingdom results in detectable accumulations of gold in many plants. Concentrations vary within individuals, among species, and with seasons. From an evaluation of the chemistry of easily acce sible organs of common pecies in the northern forests, it is concluded that alder twigs (or leaves) and conifer bark scales are the vegetation components of greatest use in the earch for concealed gold mineralization. Maximum anomaly enhancement is obtained from twigs collected in the spring. Examples are given of urvey conducted in the La Ronge Domain using 1) jack pine bark (A nglo-Rouyn and Upise Lake areas) ; 2) alder twig (McLennan Lake) ; 3) black spruce bark (Rod Zone near Mallard Lake, and at Waddy Lake) ; and 4) multi-media (Tower Lake). At the latter two sites gold-bearing till is blanketed with late glacial material. Gold enrichment in the plants suggest that the roots are ab orbing gold from the underlying till. Complex processe control the uptake and retention of gold in plants. An understanding of these processes pem1its biogeochemistry to assist in locating near- urface mineralization .

Jan 1, 1986

By V. G. Papangelakis, I. Guzman, S. J. Thorpe

Pressure oxidation (POX) leaching has been commercially applied to refractory gold ores since the 1980s. In the process, sulphide material is oxidized and dissolved in order to release the gold encapsulated in the sulphide matrix, making the gold available for further recovery. Redox potential is a significant parameter during POX, however it is only measured ex-situ at atmospheric conditions. In-situ redox potential measurement would provide instant information that allowing adjusting the process parameters accordingly. In the present study, redox potential measurements were performed during POX of sulphide material at high temperatures and high pressures. The working electrode was an Ir electrode combined with a flow-through reference electrode in a novel and robust configuration. Experiments were performed in a 2 L titanium autoclave, at 200–220°C, 50–110 psi oxygen overpressure, and 10–30% solids mass fraction. Temperature and oxygen pressure conditions were selected in order to reflect POX of refractory gold ores. Results show that the Ir electrode is consistent with theory and is able to perform well under these conditions, showing promise as a new in-situ sensor.

Jan 1, 2017

By Edward Martinez

Due to its unique properties, chrysotile asbestos is used in many diversified applications. In recent years, a better understanding of the structure and properties of chrysotile has evolved due to the research efforts of many investigators. A summary of the results of some of these investigations is given. An attempt is made to show the relationships between the properties of chrysotile and its crystal structure. Examples taken from the literature are cited in which methods have been developed for modifying the properties to improve the performance of asbestos in some applications. These include the effect of pH on the positive zeta potential and the addition of sodium silicate to improve filtration characteristics. The dehydroxylation and formation of forsterite when chrysotile is heated are also discussed.

Jan 1, 1966

By R. S. Boorman, H. G. Ansell

"Poor separation of lead from a copper concentrate of a major base metal producer was thought to have resulted from copper (0.2-0.4%) in the galena which caused it to float with chalcopyrite. No inclusions of copper mineral were detected which could account for the flotation of galena. The tendency for copper-bearing galena to float with chalcopyrite was confirmed by Hallimond-tube experiments in which the floatability of copper-doped synthetic galena (0.1-0.4% Cu) was approximately four times as high as copper-free galena. The difference in the cell edge (5.9338 ± 0.0003 A, Cudoped galena; 5.9361 ± 0.0002 A, Cu-free galena) indicated that the copper was lattice-bound and did not occur as submicroscopic mineral inclusions."

Jan 1, 1973

By A. E. McIlhinney, I. E. Puddington, C. E. Capes, A. F. Sirianni

"Two main problems are associated with the removal of pyritic sulphur from coals. The first is due to the fine state of dissemination of pyrite, which requires grindin1 to a very fine size to accomplish liberation. The second problem is caused by the similar surface chemical characteristics of coal and pyrite, which complicates separatio11 methods based on this property. In the work described here, the problem of fine particle size was overcome by using the selective oil agglomeratioa method developed at the National Research Council of Canada. Recovery of more than 90% of the combustible values was possible, even with particles only a few microns in diameter. Experiments using conventional chemical depressants for pyrite met with little success. It was found, however, that pyrite may be rejected during coal agglomeration through treatment with the iron.oxidizing bacteria, thiobacillus-ferrooxidans. The conditions for maximum pyrite separation are described and possible mechanisms by which the bacteria act are discussed."

Jan 1, 1973

By V. A. G. Preto, W. H. White, J. E. Harakal

Potassium-argon age dating performed recently on intrusive rocks from Copper Mountain indicates that the satellite Smelter Lakes and Voigt stocks have radio-metric ages which are indistinguishable from that of the Copper Mountain stock, as determined by Sinclair and White (1967). The complex of intrusive rocks known as the Lost Horse Intrusions also yields essentially the same radiometric age, as do biotite-sulphide-pegmatite veins on Copper Mountain.

Jan 1, 1971

By Paul G. Dunn

The planning of underground mines is a complicated process involving geological, engineering and operational constraints. MIRARCO is in the process of developing a 5D Mining Exploratorium where 3D mining models are combined with time (4th dimension) and costs (5th dimension). The mining exploratorium is a collection of external and inhouse software packages specifically geared to help underground mining companies arrive at better mine plans. This paper discusses the progress made in the development of the 5D Mining Exploratorium and a change in mine planning philosophy by conducting frequent audits in a Virtual Reality Laboratory. The development of genetic algorithms for optimising stope sequences is also presented.

May 1, 2003