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By Alan A. Barton

Introduction The Little Long Lac mine is situated in the Thunder Bay mining district, township of Errington, Ontario. The mine is located on the south side of the most westerly bay of Little Long Lac. The property consists of 36 claims, which comprise some 1,400 acres. This group of claims was staked in August, 1932, by Tony Oklend and Tom Johnson, and, after surface sampling, was optioned by the present controlling interests, who diamond-drilled it during the winter of 1932-33. In early spring, a small steam-driven plant was installed, and shaft sinking commenced on June 1st, 1933. During the summer, all supplies are transported to the mine from Hardrock station, at mileage 18 on the Canadian National Railway line from Longlac to Port Arthur. At Hardrock, which is seven miles from the mine, the railway skirts a bay of Little Long Lac, and supplies are loaded directly from railway cars to scows. Two scows are used, of 30-and 45-ton capacity, respectively. A 36-ft. pointer, powered by a 35 h.p. engine, is used as a tug. A good winter-road has been cut out from Geraldton to the mine, for winter transportation. Geraldton is about two miles north of the mine, and is also located on the Canadian National railway. A hard-surface road is now being constructed for summer as well as winter use. Geology The Little Long Lac gold area covers the northern limits of a large synclinal structure, the contact of the Keewatin flows and sediments, striking about twenty degrees north of west, with the dip of the sediments varying from eighty degrees north to seventy degrees south, the average being around eighty degrees south. The vein worked by Little Long Lac Gold Mines occurs in massive sedimentary rock of about the composition of arkosic or quartzitic greywacke, and consists of a shear-zone up to fifteen feet in width, striking N.75°E. and dipping steeply to the south, which has been filled by numerous narrow, parallel quartz veins and. veinlets. These are well mineralized. with arsenopyrite, pyrite, and some chalcopyrite and stibnite, and carry considerable quantities of visible gold. They show more than one age of quartz deposition, the quartz being fractured and re-cemented. The arkosic rocks separating the veins and veinlets are also slightly mineralized with pyrite. Work to date has indicated the probability that the vein-shear is controlled by local drag-folding.

Jan 1, 1935

By M. Sanchez

In the last decades, the Chilean copper mining and metallurgical industry have had to modify their technological processes to meet the environmental regulations implemented by the Chilean government, and also to support the pressure of the public opinion. Thus, air quality standards for sulfur dioxide and particulate matter (primary and secondary), plans for reducing emission of arsenic by the Chilean copper smelters, effluents discharge limits, among others regulations were applied by the environmental agency. Additionally, agreements on cleaner production were carried out by mining sector and government. Now, a draft law on mine closure, and another on environmental mining wastes (abandoned mines) are being discussed by the authorities and the mining sector. In the context, production and environmental impacts in different ways to produce copper in the Chilean mining industry are reviewed and regulatory tendencies as well as abatement technologies today used are exposed and discussed in this presentation. Pyro, hydro and electrometallurgical processes employed and their current effluent and contaminants are presented showing various alternatives of treatment in the copper industry. An update of regulations established in Chile vis a vis copper production, with an especial attention to mine closure are also presented.

Jan 1, 2007

By S. Caron

From the early 70?s, ?Centre de Recherche Minérale? (CRM) has conducted and co-ordinated Research and Development activities for the mineralurgical and metallurgical industries. Since 1999, CRM has continued its mandate through COREM which is a consortium of 13 members that uses the benefits and advantages of collaborative pre-competitive industry / university research. In particular, COREM?s ?In-Situ Optimization Group? is involved in the implementation of modern optimization and control tools. The POP Project was launched in order to increase and consolidate the use of modern optimization and control tools and methods for mineralurgical and metallurgical processes. To ensure a successful transfer in the industry, there are a number of essential activities that have to be undertaken. These activities have been identified by COREM?s members and are grouped into three main modules: - R&D Module: Research and Development in universities, research centres and other partners; - Technology Transfer Module: integration of new tools and methods into the POP Software, industrial applications and technical support; - Training Module: education of new engineers in universities, continuing education of plant personnel through on-site workshops and resource networking by specific information exchange tools. This paper outlines the opportunities that led to the definition of the POP Project and describes its main modules. The main features of the POP Software are presented, the first application is described and finally, future developments are discussed.

May 1, 2001

By A. H. Duffield

"Forming part of the Prairie Evaporites, the sylvinite layer mined at Alwinsal underlies the Blairmore quicksands and the water-bearing Devonian formations. Production is achieved by a method of trackless, continuous mining of rooms, leaving pillars for natural support. The paper describes the development of the mine, and the equipment and organization employed in the operation and maintenance of the underground facilities."

Jan 1, 1972

By J. M. Belland

This paper deals with the geology of the Smallwood mine in relation to its influence on mining and milling operations. Structure within the orebody, and variations in ore grade and material types, will be described and associated with the various drilling, blasting and milling operations. The orientation of planes of weakness, either bedding or jointing planes, and contacts between extremes in material types influence the size of the broken material. Generally speaking, variations in grinding rates and recovery can be associated with stratigraphic sequence and metamorphism.

Jan 1, 1966

By A. C. de Araujo, M. G. Barbosa, R. Martino, S. Gaydardzhiev

The Iron Quadrangle district is a world-class iron ore mining district in the region of Belo Horizonte, capital of Minas Gerais state, in Brazil. Many mining companies have been mining high-grade hematite ores for decades throughout the region. The mines reserves often include itabirite ores which are available in high volumes, but have lower iron grades than hematite ores and require elaborated mineral processing to meet the requirements of downstream steelmaking. Itabirite ores have acquired importance, with the depletion of high-grade hematite reserves due to their intensive mining. The objective of this paper is to propose a geometallurgical model for the processing of itabirite ores from an Iron Quadrangle deposit, which will allow predicting the behaviour of ores throughout the deposit, according to their local variations. An initial step consists in characterizing representative samples of the different ores to acquire mineralogical and textural data. Then, itabirite ores of known characteristics are processed with different techniques, in order to extract the trends and key parameters upon which the geometallurgical model is developed. At first, the model takes into account the particle size distribution and its shift during mining and screening, as well as the chemistry and mineralogy of the material. Then, using the previously identified key parameters such as iron recovery, the model predicts the composition of the processing products. Finally, this data is used to model the mineralogy and mass recovery of the products. The geometallurgical model is of great importance, as it is able to model the processing of any sampled ore throughout the deposit. The incorporation of the results in a mining block model will assist mine planning and opens new opportunities for an optimized mining schedule.

Jan 1, 2016

By H. Kolcz, G. S. Dobby, R. Stratton-Crawley, S. W. Wilson

"The Matte Separation plant at Inco's Copper Cliff Smelter Complex is described. The continuing implementation of flotation column technology in the flowsheet in various applications is reviewed. Comparative studies on 0.038, 0.10, 1.1 and 1.8 m diameter columns have been carried out. It was demonstrated that consistent metallurgical performance was obtained with both pilot- and plant-scale units. Grade-recovery relationships for plant columns can be predicted with confidence from data obtained from test equipment. The work indicates further areas of the flowsheet in which columns present an attractive alternative to conventional cells. INCO’s MATTE SEPARATION PROCESSNickel concentrate from Inco’s Sudbury area mills has been processed in the Copper Cliff smelter for sixty years. Prior to that, Sudbury ores had been smelted directly. Historically, copper-nickel separation from smelter converter matte was achieved by the classical Orford process. In the mid-1940s Inco developed an improved separation scheme based on mineral processing methods, the Matte Separation Process. A generalized Copper Cliff Smelter Complex flowsheet is shown in Figure 1.Iron sulfide and gangue contained in the nickel concentrate are rejected in the smelting-converting process. The molten product, typically containing 50% Ni, 25% CU and 22% s, is cast at about 1000 ºC, into floor moulds and allowed to slowly cool for four days. During this period nickel sulfide (heazlewoodite, Ni,S,), copper sulfide (chalcocite, cu,S) and a copper-nickel metallic alloy precipitate and form a coarse grain structure that is amenable to separation by physical means. The phase chemistry of this system has been described previously by Sproule et al (1). This matte then becomes the feed to the Matte Separation Process.A simplified block flowsheet of the Matte Separation Process is shown in Figure 2. Matte ingots, typically weighing 20 tonnes each, are broken and crushed in a three stage crushing plant to approximately minus 0.01 m and conveyed to the Matte Separation building. Grinding is carried out in two parallel circuits each consisting of a rod and ball mill in series producing a flotation feed which is 65% minus 44 microns. Typical throughput of each grinding circuit is 650 tonnes/day. The metallic fraction of the feed is recovered by magnetic separation. This product, containing about 66% Ni and 15% CU, is a major component of the feed to the Copper Cliff Nickel Refinery."

Jan 1, 1990

By K. Östcrdahl

We are developing a cost-saving and environmentally friendly process with low energy consumption to recover the metal content and recycle the acid from spent pickle baths. The metals are precipitated as metal fluorides, which can be turned into metal oxides and hydrofluoric acid by thermal hydrolysis. In the proposed process the solution is concentrated by nanofiltration and the metals are precipitated in a subsequent crystallization step. Different nanofiltration membranes have been evaluated in experimental batch tests. The membrane MPF-34 from Koch Membrane Systems offered both good flux and acceptable metal retention even after long periods of acid storage. The solubility of B-FeF3.3H20 has been measured at varying acid concentrations and at different temperatures. The solubility decreases with increasing hydrofluoric acid and nitric acid concentrations. This suggests that the crystallization process should be operated at high acid concentrations. The crystal growth rate of B-FeF3.3H2O is found to be quite low but increases significantly with temperature. This suggests that the crystallization process should be operated at higher temperatures (40 - 60°C). Within the project a pilot plant has been constructed where the spent pickle bath solution is concentrated by nanofiltration to the desired metal fluoride supersaturation, and B-FeF3.3H2O is crystallized in a 10 L continuous crystallizer.

Jan 1, 2006

By J. Jin, J. D. Miller

"Bubble attachment at hydrophobic surfaces is of critical importance in the flotation recovery of mineral resources and fundamental experimental results have been reported in the literature describing the details of film thinning, rupture, and displacement. Now, for the first time, bubble attachment phenomena are examined using Molecular Dynamics Simulations (MDS). The simulation involves a nitrogen bubble containing 906 nitrogen molecules in a water phase with 74,000 water molecules at the hydrophobic molybdenite (001) surface. During the simulation period of 1 ns, film rupture occurs and the nitrogen bubble attaches to the molybdenite (001) surface, resulting in a contact angle of about 90o. In contrast, the film is stable at the hydrophilic quartz (001) surface and the bubble does not attach. Contact angles, determined from MD simulation after stabilization of the three phase line of contact, are reported and these results agree well with experimental and MDS sessile drop results. In this way, film stability and bubble attachment are described with respect to interfacial water structure for surfaces of different polarity. For example, the interfacial water molecules for the hydrophobic molybdenite (001) surface have relatively weak interactions with the surface when compared to the hydrophilic quartz (001) surface, as revealed bythe presence of a 3 A water exclusion zone at the molybdenite/water interface. INTRODUCTIONAttachment of air bubbles to mineral particles is of fundamental importance in understanding flotation separation phenomena. It is well known that attachment of an air bubble at a hydrophobic surface includes film thinning, film rupture, and film displacement (Somasundaran, 2006; Wilson, Adlard, Cooke, & Poole, 2000). Experimental techniques, such as high speed video, can catch the process of bubble attachment at a mineral surface (Drelich & Miller, 2012; Niecikowska, Krasowska, Ralston, & Malysa, 2012). However, molecular scale information to examine the phenomena has not yet been reported."

Jan 1, 2016

By M. Mai Manga, M. Renaud, A. Faucher, C. Bazin

ABSTRACT Grinding circuits are operated in the presence of disturbances resulting from ore changes and equipment malfunctions, such as hydrocyclone overloading, worn or partly plugged apexes, surging, and internal liner detachment that may cause a loss of classification performance. Metal recovery losses in downstream leaching or flotation circuits justify the development of methods for rapid detection of hydrocyclone malfunction. Two methods are presented in this paper. The first method uses measurements from sensors available in a grinding circuit and the second uses vibration sensors installed on the individual hydrocyclones of a nest.

Jan 1, 2011

By D. Racicot, T. Hanel, E. H. Chown

Over thirty plutons in the Chibougamau-Desmaraisville belt were examined briefly in the field and sampled, in addition to the few masses that have been studied in detail. The survey indicates that the intrusions may be conveniently grouped in four main categories, based on their time of intrusion. These are; remobilized basement domes, pre-kinematic intrusions, syn-kinematic intrusions and postkinematic intrusions. Basement domes, as exemplified by the Lappa rent Massif, are composed of migmatized tonalite-diorite gneiss that has undergone at least two periods of mafic dyke intrusion and at least three major deformational periods. The rise of the basement domes was accompanied by extensive mylonitization and the intrusion of syn-tectonic plutons. Pre-kinematic plutons, such the Chibougamau pluton, are diori te-tonalite in composition, and were intruded into the supracrustal pile and partly eroded before the main deformation of the belt. Syn-kinematic plutons occur principally as marginal intrusions bordering the belt (Barlow), or as discrete intrusions along structural highs (La Dauversiere), and are either hornblende monzodiorite or tonalite in composition. Post-kinematic plutons, such as Muscocho, are principally granodiorite and often porphyritic intrusions locally deforming the enclosing rocks. The close relationship between mineralization and high-level intrusions such as the pre-kinematic and some of the post-kinematic plutons is discussed.

Jan 1, 1984

By K. Becerra, D. G. Almond, T. D. Maru

"Nkomati Nickel Mine in South Africa processes one of the world’s hardest ores in a 375k TPM autogenous grinding circuit. The plant employs an unconventional processing circuit, comprising a primary autogenous mill (AG or FAG) and pebble crushing circuit followed by a secondary hybrid pebble/ball mill and classification cyclone cluster.Advanced Process Control (APC) or Expert Control is now generally accepted as an advantage in most modern high capacity concentrator grinding circuits. This paper reviews the installation of model predictive control at Nkomati and examines the results and benefits of installation in an autogenous mill during plant ramp-up. The paper also demonstrates how predefining process control objectives together with good plant and supplier cooperation can achieve a robust and reliable APC implementation on a very short site program.The results conclusively demonstrate operational and economic benefits during circuit operation with the advanced process control system ON. Production performance and circuit stability were significantly better than during manual control."

Jan 1, 2012

By X. Cao

Friction stir processing (FSP) is used to produce wrought microstructures at the surface of sand-cast aerospace grade magnesium alloy ZE41A-T5. It is found that the microstructure is significantly refined in the stir zone and the flow arm. The stir zone is largely comprised of equiaxed magnesium grains of approximately 4.5 pm compared with about 50 µm in the base cast material. In the stir zone, however, abnormal growth of some grains is also observed. Vickers microindentation hardness tests indicated that the stir zone experiences some increases in hardness. Single surface passes with low distortion, lack of pores and cracks were successfully obtained indicating the great potential of the FSP technique for modifying, improving and repairing magnesium alloy castings. This will probably open new opportunities to apply magnesium alloys in aerospace industry.

Jan 1, 2007

By Nader Golchinfar

The V-shaped breakout zones around excavation boundary have been captured by a variety of numerical methods such as FEM and DEM methods and failure criteria such as linear Mohr-Coulomb and non-linear Hoek-Brown failure criteria. Diederichs (2007) used Hoek-Brown parameters in his spalling parameter approach; however, it is convenient to use the Mohr-Coulomb failure criterion in numerical modeling because the material parameters can easily be determined from triaxial tests. It is shown in this study that when peak and residual strength parameters as well as dilation angle are properly defined, the brittle Mohr-Coulomb failure criterion can be used to model depth of failure near underground excavations satisfactorily.

Jun 1, 2012

By R W. Drybrough

The program to increase production at Sherritt Gordon's Lynn Lake property, which began in 1956, included increasing the rope speed and the horsepower of the ore hoist at the "A" shaft. Because of the limited power sup-ply from the two 7,000-hp. hydroelectric plants, and the ? 3,600 hp. predicted for the combined hoisting requirements of the three production shafts, it was considered desirable to lessen the impact of this type of load on the relatively small power system by equipping all future hoisting arrangements with Ward Leonard direct-current drives. The manually operated 8-by 4-ft. hoist at the "A" shaft had a rope speed of 1000 f.p.m., and was driven by a 385-hp., 380-r.p.m. wound rotor motor with liquid rheostat control. This A.C. drive was replaced by a semi-automatic Ward Leonard direct-current drive with a 515-hp., 566-r.p.m., shunt wound motor, providing a rope speed of 1,500 f.p.m. During several months preceding the con-version, all possible preparations were carried out to keep the changeover period to a minimum, and this resulted in a total shutdown time of twelve days. The capability of the "A" Shaft hoist was increased from 109 tons per hour to 134 tons per hour, and both mechanical and electrical maintenance were reduced considerably. The total cost of the conversion amounted to $130,000. The hoistmen who had been required for the manual A.C. drive were transferred to the new Farley shaft, and the reduction in operating labour costs of the "A" Shaft hoist

Jan 1, 1965

By Yutaro Fukase

Various types of service robots have recently been developed for guarding facilities, caring for the elderly, carrying objects, and cleaning buildings. As barrier-free facilities improve and their use expands, these robots have more space within which to move inside buildings. Yet robots that move autonomously rely on position-detection systems. Though improving rapidly, these systems are far from perfect in determining positions in certain situations, especially when robots navigate large areas or cross various locations. Our group is working to solve this problem by developing a position-detection system using random-dot patterns on a floor. First, we construct a floor with a random-dot pattern and register the positions of all of the dots into a database. As the robot moves across the floor, a camera on the robot captures an image of the floor beneath it and crops the dot pattern in the image. The cropped dot pattern is matched to the dot patterns in the database to determine the position of the robot and the direction in which the robot is facing or moving. In this paper we propose a self-localization system and matching algorithms derived from a space technology and present the results of several experiments.

Aug 1, 2013

By P. Leo

The hot deformation behavior of a Mg-9A1-1Zn alloy produced by high pressure die casting has been investigated by means of compression tests in the temperature and strain rate ranges of 125-300°C and 10-5-10-1 s-1 and torsion tests over 150-450°C and 5, 0.5, 0.05 5-1 . The compression samples were deformed in the die-cast state or after homogenization at 415°C for 2 h to evaluate improvements. A premature fracture at 45° with respect to the compression axis was observed in samples strained at low temperatures and high strain rates. The torsion specimens were tested as received or after a predeformation-homogenization treatment. In addition to constitutive analyses suitable for modeling previously published, the results are fitted to a relationship between strain rate normalized by diffusion coefficient and flow stress normalized by modulus. The results fit well with a set of published creep experiments that were conducted in the range of 70-150°C.

Jan 1, 2006

By Akihiko Nishiyama

Unmanned construction technology used for remote control operation of construction machines has some problems to solve compared with manned operation of construction machines, such as fatigue due to long-term operation or decreases in operational efficiency. To solve these problems, we recorded the viewpoints of operators in both manned and remote control operation and analyzed the differences. This paper reports on our discussion of improving the operability of remote control operation based on the analysis results.

Aug 1, 2013

By E. De Souza

Energy associated with ventilating an underground operation comprises a significant portion of a mine operation's base energy demand and is consequently responsible for a large percentage of the total operating costs. Ventilation systems may account from 25?40% of the total energy costs and 40?50% of the energy consumption of a mine operation. Fans are the most important mechanical devices used to ventilate underground mines and the total fan power installed in a single mine operation can easily exceed 10,000 kW. Investigations of a number of mine main fan installations have determined their assemblage to be, in general, very energy inefficient. The author has found that 40?80% of the energy consumed by a main fan is used to overcome the resistance of fan assemblage components. This paper presents how engineering design principles can be applied to improve the performance and efficiency of fan installations, resulting in substantial reductions in power consumption, operating cost and greenhouse gas emissions. A detailed case study is presented to demonstrate that, by designing fan assemblages using proper engineering concepts of fluid physics and industrial ventilation design, main fan systems will operate at efficiencies well above 80?90% (compared to common operating efficiencies of between 20 and 65%), resulting in a drastic reduction in a mine's overall costs and base electrical and energy loads.

Aug 1, 2013

By Jamal Jafari, Abbas Sam

"The concentration of the fourth production line at Golgohar includes 66% iron with Blaine number of 500 cm2/g. For pelletizing process, the feed iron grade should be greater than 68% with minimum Blaine number of 1800 cm2/g. In this study, the low intensity magnetic Separators, particularly the feed particle size distribution of LIMS were considered. The feed particle size distribution of the separators was optimized to prepare an appropriate concentrate (as mill pelletizing feed). The samples were performed from the LIMS feed and after grinding, four d80 (64, 103, 132, and 15 3µm) were prepared. Then, laboratory magnetic separation experiments were conducted on these samples. The best results obtained using d80 of 132µm. In this particle fraction, the iron grade and Blaine number were 70.3% and 1571 cm2/g, respectively. Therefore, it seems necessary to include a grinding and classification systems before LIMS stage. According to the presence of a high amount of -132 µm particles in the initial feed, an inverse closed circuit was selected. The hydrocyclone was designed in three units as the classification system with 62 cm (diameter), 22 cm (overflow outlet) and 11 cm (apex diameter). By simulation of hydrocyclone with USIMPAC software, the size distribution of underflow was determined. Based on these results, a ball mill with dimensions of 6.7 m (length) and 5 m (diameter) was designed as grinding system.INTRODUCTIONGole-Gohar iron ore concentration plant No.4 (Polycom Plant) in Gole-Gohar Industrial and Mining Complex was installed to increase production capacity as well as treating the circulating load from AG and SAG mills of the main concentration plant of the complex. The load from the mine is crushed using jaw and cone crushers. The crushed ore is then combined with the circulated load and the combination is then grounded using HPGR and ball mills respectively.After comminution, there is a magnetic separation plant which includes a medium intensity magnetic separator (MIMS) followed by three low intensity magnetic separators (LIMS). Final concentrate dewatering is done using three belt filters. After the primary magnetic separation, the ore is upgraded to 62% Fe content and final concentrate which is the product of LIMS has 66% Fe content."

Jan 1, 2016