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By J. E. Dutrizac

The dissolution of low-iron sphalerite, (Zn,Fe)S containing 0.08% Fe, in ferric sulphate-sulphuric acid media was investigated using closely sized fractions of crushed sphalerite crystals and sintered disks made from the crushed crystals. Linear kinetics are observed, and the predominant reaction products are ZnSO4, FeSO4 and elemental sulphur. The leaching rate increases systematically with increasing temperature, and the calculated apparent activation energy is 56 kJ/mol for the sized sphalerite and 54 kJ/mol for the sintered disks. The relatively high apparent activation energy suggests that the rate is chemically controlled, a conclusion supported by the insensitivity of the rate to the disk rotation speed. The rate increases as the 0.22 power of the Fe(SO4)1.5 concentration, and as the 0.22 power of the H2SO4 concentration. However, in the absence of ferric ions, the rate increases more significantly with increasing H2SO4 concentrations, and relatively rapid rates are observed in solutions containing >0.5 M H2SO4. In 0.1 M Fe(SO4)1.5-0.3 M H2SO4 media, the measured rate decreases with increasing sulphate concentrations, added as Li2SO4. The rate of dissolution of low-iron sphalerite is promoted by dissolved copper concentrations as high as 800 mg/L. In contrast, dissolved silver, even in the 0-2 mg/L concentration range, significantly retards the dissolution of the low-iron sphalerite.

Jan 1, 2008

By T. Mulja, Michel Boily, Anthony E. Williams-Jones, Pierre Pilote

"The Preissac-Lacorne batholith is composed of suites of early metaluminous calc-alkalic gabbroic to granodioritic intrusives, three late peraluminous monzogranite plutons and numerous Li, Be and Ta-bearing granitic pegmatites. The Lacorne pluton is dominated by biotite and biotite + muscovite monzogranites containing abundant Be and Ta-bearing granitic pegmatites (40-80% volume). The pluton is surrounded by swarms of unzoned or poorly zoned spodumene-rich pegmatite dykes. The La Motte pluton is composed of biotite monzogranites, biotite+ muscovite monzogranites and rare muscovite + garnet monzogranites. Li, Be and Ta-bearing pegmatites are less abundant than in the Lacorne pluton and are commonly associated with molybdenite bearing quartz-muscovite-K-feldspar veins. In the Preissac pluton, muscovite + garnet monzogranites and muscovite + biotite + garnet monzogranites are the dominant rock types. The pluton rarely contains granitic pegmatites and these are generally barren. However, numerous molybdenite bearing quartz and quartz-feldspar-muscovite hydrothermal veins are observed.Li, Be andTa-bearing pegmatites display a crude spatial zonation around their parent monzogranites. Spodumene-rich pegmatites are generally unzoned or poorly zoned and are confined to the surrounding metasedimentary or metavolcanic rocks or crop out in the early gabbroic to granodioritic intrusives surrounding the monzogranites. Ta and Be-bearing pegmatites are usually concentrated towards the margins of their parent monzogranites. The highly fractionated nature ofmonzogranites (high Rb/Sr, low K?Rb, Ba?Sr, Zr/Nb ... ), their peraluminous composition (corundum normative and muscovite bearing) and the numerous occurrences of Ta and Be-bearing pegmatite dykes represent important criteria for the exploration of fertile granites."

Jan 1, 1990

By Frederick Biery

Outline ? Project Challenges ? Results from 100 recent projects ? What factors are driving the best and worst projects ? A look at recent mining projects ? Conclusions

May 1, 2009

By C. A. D' Odorico

The zinc pressure leaching (ZPL) plant at Teck Cominco's Trail Operations was started up in 1981 and represented the world's first commercialization of the technology. From the outset, the process was designed to operate using iron-rich Sullivan Mine zinc concentrate. When the Sullivan Mine reached the end of its life in 2002, the ZPL plant underwent a significant process change with the treatment of 100% Red Dog zinc concentrate. Through careful improvements to existing plant processes, controlled changes to plant operating parameters and a rapid adjustment to the modified process by operations personnel, the plant has been successfully converted to processing a feed of 100% Red Dog zinc concentrate. This paper discusses the challenges faced during the conversion and describes the modifications to plant operating procedures, as well as changes to plant processes.

Jan 1, 2004

By J. W. Matousek

"Computer modeling of smelting processes requires internally consistent equations for calculating the compositions of mattes and slags. That is, the sum of the calculated assays must total 100%. One set of equations that satisfies this requirement for copper produced under oxidizing conditions (pSO2>one atmosphere pressure) is given by the following:%[Fe] = 62.0 – 0.775%[Cu]%[S] = 28.0 – 0.00125%[Cu]2%[O] = 10.0 – 0.225%[Cu] + 0.00125 %[Cu]2Mattes containing nickel in appreciable quantities do not have the defined “white metal” end point of approximately 80 percent copper and 20 percent sulphur that is found in the copper system during the converting process. The above equations, however, are readily extended to nickel and nickel/copper mattes for any desired end product composition."

Jan 1, 1996

By D. V. Dorling, J. T. Bowker, J. A. Gianetto

Over the last few years, interest in the development and construction of large diameter, high pressure pipelines from the Mackenzie Delta in northern Canada and Alaska's North Slope has steadily increased as a result of the projected decline in recoverable natural gas from existing reserves in western Canada. The success of such enormous pipeline projects, which will require utilization of a strain-based design approach, is largely based on successful application of high strength line pipe steels, such as X80 and X100. To fully realize the economic benefits of high strength steels, welding processes and procedures must be developed to ensure that the requirements for high strength and good low temperature toughness are confidently obtainable in field girth welds used in the construction of such pipelines. This study aims to provide a better understanding of the factors that control weld metal strength and toughness for a series of mechanized X100 girth welds produced using a range of narrow-gap gas-metal arc welding procedures. The attainment of high yield strength (> 810 MPa) is considered to be an important target to ensure overmatching strength relative to the longitudinal property distribution of X100 line pipe steel. Some factors that have been considered in this evaluation include influences of gas-metal arc welding process variants (single and multi-wire) and changes in welding procedure specifications, including joint preparation. Key components of this work relate to the reliable measurement of weld metal strength variation through-thickness and as a function of position around the circumference of a given girth weld.

Jan 1, 2005

By J. E. Hawley

"The Aldermac copper deposit is in Beauchastel township, Abitibi county, Quebec. It lies about 11 miles west of Noranda. It has been described by Cooke, James, and Mawdsley(2) and by Bruce(3) and has been mapped in detail by W. Samuel and the late K. W. Fritzsche, former Mine Geologist, and by J . E. Gill and A. R. Byers, so that most of the particulars contained in the description that follows are largely the result of the work of others than the writer, whose connection with the deposit, in a consulting capacity, extended over the last 5 years of the life of the mine.According to A. V. Corlett, former Mine Manager, the property was staked during the early winter months of 1923 because of its location adjacent to the syenite intrusive that had been mapped by Cooke near the height-of-land in this township. An examination by Mr. Corlett in 1924 revealed mineralized zones to the north of MacKay lake, and in the vicinity of these K. W. Fritzsche, by dip needle and trenching, discovered the No. 1 and No. 2 deposits, which were both too small and too low grade for exploitation. During the winter of 1925, A. A. MacKay, with a dip needle, picked up a magnetic 'anomaly' in a drift-covered area about 600 feet to the north of previous workings. Trenching here revealed only a narrow zone of mineralization of little consequence, but, farther east, MacKay discovered a more pronounced 'anomaly' over what later drilling and underground work proved to be ore of commercial grade (No. 3 and No. 4 orebodies)."

Jan 1, 1954

By P. Radziszewski

"The comminution energy curve is a profoundly simple graphical technique that displays detailed operating efficiency information for industrial comminution processes. The database underlying the methodology has recently more than doubled, to now contain a substantial fraction of the international comminution output (1.7 billion tonnes of rock per year) across more than 8 major commodities. This increase has deepened the analytical capabilities and effectiveness for assessing comminution circuit performance in relation to comparable operating mines. This paper will explore how the energy curve methodology can be used to examine the ability of stirred mill technologies to increase efficiency.Specifically, this paper explores how the energy curves methodology can be used to present energy efficiency gains achieved at three mines employing a stirred mill technology under different duties. The first of these cases studies was conducted by Rosa (2014) who compared the performance of two ball mills operating in parallel with a Vertimill in the regrinding circuit at the Samarco Iron project in South East Brazil. The Vertimill was found to achieve the same product specification while consuming 40% less energy. Brissette (2010) investigated the impact of grinding media on the performance of both ball mills and Vertimills. The energy savings achieved varied from 10% to 40% for the ball mills and 30% to 60% for the Vertimills. Lastly, Bergerman (2012) investigated the operating conditions of the Sossego regrind circuit from 2006 to 2011 against design specifications and laboratory testing. The operating work index of this circuit varied from 5.2 kWh/t to 44 kWh/t over this 5 year period. The full suite of energy curves"

Jan 1, 2016

By P. H. Reynolds, S. Liaghat, A. Zarasvandi

"Darreh-Zerreshk and Ali-Abad are two relatively small porphyry copper-type deposits in Yazd Province in central Iran. They are located within the central Iranian volcano-plutonic belt, formed above the collisional convergent margin of the Iranian lithospheric plate from the late Eocene to the Miocene. This paper discusses the geochemical characteristics of the igneous rocks, and 40Ar/39Ar geochronology of plutons and alteration phases associated with the Darreh-Zerreshk and Ali-Abad deposits. The deposits are spatially associated with igneous complexes that consist of older and barren granites intruded by intermediate-composition granitoids, which are the carriers of Cu mineralization. The granites have relatively high content of Nb, Y, and K, a prominent negative Eu anomaly, and were probably derived from melting of, or contamination of mantle-derived magmas by, continental crust. Porphyritic diorites, quartz monzodiorites, and granodiorites show enrichment in light rare earth and large-ion lithophile elements, depletion in middle rare earth elements, and have no negative Eu anomaly. These intermediate-composition granitoids were derived from melting of the upper mantle or lower crust, and their differentiation was controlled partly by fractionation of hornblende. A pilot K/Ar whole-rock dating study suggests that the pre-ore granites were emplaced in the Oligocene. Dating by the 40Ar/39Ar method of nine samples of secondary biotite and sericitized rocks from drillcore within the mineralized and altered zones in both deposits yielded a well-defined age of ca. 16 Ma. This date is interpreted to be the time of hydrothermal alteration and of porphyry copper type mineralization in this part of Iran."

Jan 1, 2007

By E. McLaren, J. Sanftenberg, C. Cameron, H. Dello Sbarba

"A Ventilation on Demand (VOD) system has been optimized and maintained at Glencore’s Nickel Rim South Mine (NRS) in Sudbury, Ontario, Canada for the past seven years. The system monitors and controls air quality and quantity through real-time, dynamic automation of primary fans, secondary fans, automated airflow regulators, and air monitoring instrumentation with VentSim™ CONTROL, a VOD software. This paper will focus on the implementation of testing procedures and system maintenance methods. Overall, the results show a consistent reduction in energy usage.INTRODUCTIONThe Ventilation on Demand (VOD) system at Glencore’s Nickel Rim South (NRS) mine in Sudbury, Ontario, Canada, involves the control of two 2,980 kW centrifugal surface exhaust fans with Variable Frequency Drives (VFDs), three 335 kW vane-axial surface intake fans with VFDs, 21 automated airflow regulators, six automated dampers, seven automatic doors and 198 underground auxiliary fans with ON/OFF starters. Additionally, the system monitors airflow at 48 locations, carbon monoxide (CO) at 40 locations, nitrogen dioxide (NO2) at 21 locations, and dry bulb and wet bulb temperature at 21 locations. The VOD system is also integrated with a tagging and tracking system to modulate the ventilation system automatically and in real time according to the presence and position of the personnel and vehicles. The tracking system comprises of 75 vehicle tags with diesel status and hydraulic status (ON or OFF), 440 personnel tags, and 200 tracking zones. Finally, it also involves the configuration and updating of 55 level plan and interactive procedures and 24 daily scheduled events. NRS currently uses VentSim™ CONTROL, Ekahau Tracking and PI Datalink to control, monitor, and configure their VOD system."

Jan 1, 2019

By Harry Siewert

"The commissioning of the 4th concentrator (C4) at Freeport Indonesia in early 1998 increased total mill throughput from 130k to 230k tonnes per day. The C4 flowsheet consists of a single 38 ft diameter SAG mill, four 24 ft diameter ball mills followed by four banks of 4,500 ft3 WEMCO flotation cells.The design of the C4 rougher flotation circuit was based on the expectation that the copper and gold recoveries achieved with the 4500 ft3 flotation cells would be equivalent to or better than that achieved with the 3,000 ft3 flotation cells in the 3rd concentrator (C3) rougher circuit. This assumption was due to the fact that the C4 flotation feed size would be less than 15% +212 microns compared to the C3 rougher flotation feed size of less than 23% +212 microns. By mid 1998 it had become apparent that the C4 rougher flotation copper and gold recoveries were below those predicted.In order to determine the cause of the lower recoveries, stage by stage rougher flotation surveys were performed in all four concentrators. The results of the surveys showed that the C4 rougher flotation circuit had a lower recovery of +200 micron material than that achieved in the C 1, C2 and C3 concentrators. Through mineralogical analysis, it was determined that a majority of the copper contained in the +200 micron fractions was liberated and recoverable. This paper describes the steps taken to increase coarse particle recovery, overall plant recovery and the results achieved."

Jan 1, 2001

By Laszlo Imreh, Pierre Trudel, André C. Tessier

"The Siscoe gold mine is ranked as the fourth largest mine in the history of the Val d' Or mining district with a total production of 27.4 tAufrom1929 to 1949. Most of the gold mineralization occurred in quartz veins, hosted in a small (.69 km2) intrusion of altered quartz gabbro known as the Siscoe stock. The southern contact of the Siscoe stock is crosscut by a major shear zone (the ""K"" zone) trending 295/80 NE and from which gold mineralization was also exploited within the limits of the stock. Field and petrographic observations of the Siscoe stock combined with chemical analyses of major, trace and rare earth elements of the stock and its volcanic host rocks (Dubuisson Formation) suggest that:The Siscoe stock comprises four alteration facies formed from a homogeneous precursor: 1) the actinolite - Mg-chlorite facies, characterized by low FeOt,Na2O andTiO2 , and highAlp3 and MgO; 2) the albite- Fe-chlorite facies, containing high concentrations of FeOt and Nap; 3) the Mg + Fe-chloritefacies, which is transitional between the actinolite- Mg-chlorite and albite- Fe-chloritefacies; 4) the carbonate-chlorite facies, which consists of rocks that were subjected to extreme hydrothermal alteration, is spatially associated with mineralized veins and part of the K-zone. The first three facies are depleted in SiO 2, CaO and Au, and enriched in MgO, relative to fresh rocks of the Siscoe stock and the equivalent rocks of the Dubuisson Formation.Hydrothermal fluids introduced mainly along the K-zone ""channelway"" induced three types of element remobilization, resulting in the various alteration facies: 1) redistribution of elements within the stock from one facies to another (e .g., FeOt, Nap, Ti02 migrated from the actinolite- Mg-chlorite facies to the albite- F e-chlorite and Mg + Fe-chlorite facies); 2) remobilization of elements from the intrusive rocks into veins (e.g ., SiO 2 and CaO ); 3) introduction of elements by hydrothermal fluids in rocks of the Siscoe stock (e .g., Al2O3, MgO, H2O, CO2 and FeOt).The Siscoe stock and the Dubuisson Formation form part of the same tholeiitic suite. Similarly, the Bourlamaque batholith and the Val d'Or Formation belong to a single calc-alkaline suite. In view of this relationship, dissimilarities between the petrochemistry of the Siscoe stock and the Bourlamaque batholith suggest that the two intrusions are not co-magmatic.Finally, gold may have been leached from rocks of the Siscoe stock and remobilized into the quartz-carbonate mineralized veins. In order to account for the total production at the Siscoe mine, approximately 1.2 km3 of the Siscoe stock is thought to have been partially leached of its gold."

Jan 1, 1990

By D. A. Rhys

"The Red Bluff porphyry is a tabular 2 km long north-west trending Early Jurassic quartz diorite to monzodiorite body that intrudes a folded Triassic greywacke sequence in the lskut River area, northwestern British Columbia. The porphyry is 500 m to 800 m northeast of the Snip orebody, which is a southwest-dipping shear-vein, termed the Twin zone that contains approximately 35 tonnes of gold.The intrusion associated with the mineralization is characterized by 0.3 cm to 4 cm phenocrysts of K-feldspar in a mediumgrained plagioclase porphyritic matrix. It is overprinted by pervasive sericite + quartz ± K-feldspar ± biotite (potassic) alteration characterized by intense stockworking of quartz veins containing magnetite--hematite bands. This assemblage is cut successively by quartz veins with minor iron-oxides and pyrite, and by younger pyrite veins with phyllic envelopes. The system is gold-rich but copper-poor, with typical grades between 0.25 g/t and 0.6 g/t Au, and 0.1% and 0.2% Cu. All styles of alteration and veining have similar abundances of these metals. Where southwest- and north-east dipping shear zones are developed in the porphyry, veins of all types are sheeted and foliation parallel. These sheeted zones are interpreted to be syntectonic. Asymmetric phenocrysts, folded veins and oblique foliations developed in the 130 haulageway of the Snip mine imply oblique normally-directed shear on the southwest-dipping foliation.The adjacent Twin zone is a high-grade auriferous shear-vein system that is internally banded with: (1) carbonate-chlorite-biotite veins, with textures indicating formation at least partially by wallrock replacement, and (2) dilatant quartz-sulphide veins. Veins commonly have potassic alteration envelopes that contain biotite ± calcite ± K-feldspar. The zone is highly deformed and schistose, with numerous kinematic indicators including shear bands, asymmetric folds, rotated porphyroclasts and oblique foliations that indicate a normally-directed shear sense which is parallel to that indicated by fabrics within the porphyry.Precious and base metal veins within 2 km or 3 km of the Red Bluff porphyry are zoned. Veins and shear-veins proximal to the intrusion, such as the Twin zone, are typically enriched in gold, copper and molybdenum, and have potassic alteration envelopes dominated by biotite. Distal veins usually contain relatively abundant zinc and lead and have sericitic alteration envelopes. Structures of both types have an Early Jurassic galena Pb-Pb isotope signature.The similarities in structural fabrics and alteration histories in both the Twin zone and the porphyry, the zoning of the vein systems in the area, and the apparently concordant Early Jurassic zircon U-Pb age from the porphyry and galena Pb-Pb dates from the Twin zone and surrounding vein systems suggest that intrusion, semi-brittle deformation and a large mineralizing hydrothermal system were closely related temporally and genetically."

Jan 1, 1995

By Zhiqing Zhang, Changyun Chen, Qing Liu, Lin Lin, Zhihong Jia, Guangjie Huang, Lipeng Ding

The effect of interrupted quenching (IQ) treatments on natural aging and bake hardening response of Al-Mg-Si alloy was investigated by hardness measurements, tensile test, differential scanning calorimetry (DSC) and transmission electron microscopy (TEM). The results show that interrupted quenching at 100oC could effectively suppress natural aging and improve bake hardening response. The optimized interrupted quenching treatment is 100oC for 45min, which gives the alloy a relatively low T4 temper strength and higher bake hardening response. The formation of highly dense cluster(2) during the interrupted quenching could be the reason for suppressing the natural aging and accelerating the precipitation of ß? phase during the paint bake treatment. In addition, interrupted quenching at higher temperature (170oC) results in unfavorable properties in both T4 temper and paint bake treatment. The formation of large precipitates is responsible for these undesired effects.

Jan 1, 2015

By W. Curlook, L. M. Pidgeon

THE PURPOSE of this investigation was to study part of the ternary system Co-Fe-S. Jensen ( 1) established the solubility limits of sulphur in pyrrhotite. The compound with 61.7 per cent Fe, corresponding to a formula Fe12S13, was found to melt congruently at l,192°C. Hulsmann and Weibke(2) determined the Co-S phase diagram from O to 35.2 per cent S. The solubility limits of sulphur in the com-pound Co(l-x)S were not determined. The initial object of the present in-vestigation was to determine the composition at which the compound Coci-xiS melted congruently. Once this was ascertained, it was decided to investigate the ternary system Co-Fe-S from the region of 100 per cent Co(1-x) S to the region of 100 per cent Fe12S13.

Jan 1, 1953

By Paul Clayton

Case Study ? Site: BMA Saragi Coal Mine Queensland Australia ? Model: Marion 8050 ? YOM: Mid 1970s ? Boom: 97M ? Bucket: Original capacity of 100 Tonnes upgraded to 125 tonnes at time of filtration upgrade. ? Apps: Swing, Hoist & Drag Gearboxes ? Oil: Oil Castrol Alpha TT1200 Viscosity of 1208 cSt @ 40° C (104° F) 720ltr Oil Volume Trial and Installation Justifications ? To reduce gearbox overhauls. Typical schedule being 5 years. ? Bucket upgrade from 100 tonnes to 125 tonnes. Increased gearbox demand and stress. ? Increase of overhauls out to 10 years + ? Saving per Dragline estimated to be US$8-10M in downtime and maintenance if successful. ? In compliance with BHPBilliton Global Maintenance FLAC program ? Fuels, Lubricants, Air and Coolants ? Cost Justification ? Downtime: 4 days ? Lost production: $420,000 ? Cost of parts: $162,000 ? Labour and misc: $41,000 Gearbox failure cost $623,000

May 1, 2008

By K. J. Boser

"Medium Voltage (MV) metal clad switchgear is referred to as the voltage class from 2.4 kV to 38 kV. Technological advances in circuit breaker designs over the last 20 years have given rise to retrofit options in lieu of complete replacement for older outdated circuit breaker technology. This paper examines the four MV breaking techniques that exist in industry and investigates various retrofit versus refurbish options for switchgear modernization and life extension. IntroductionThe life extension and upgrade of medium voltage circuit breakers is becoming an increasingly important issue in today’s modern industrial facilities from both a reliability and safety standpoint. Unscheduled downtime, loss of production, and plant safety issues are just some of the concerns that need to be addressed with aging switchgear. A thorough examination of the available breaking mediums allows an informed decision to be made when the time comes to assess equipment performance. If you look back over the history of medium voltage breakers, you will find that there have been four breaking techniques developed and widely used:• air magnetic;• minimum oil;• vacuum; and• SF6.Many facilities that were constructed 25 to 30 years ago relied on air magnetic or minimum oil circuit breakers in their distribution systems. At the time, these were the only “tried and tested” options and they afforded good service. Since then, however, newer technology has given us the vacuum and SF6 mediums which have both proven their reliability and monopolized the market. All the methods have their particular place in industry and what follows is a summary of the advantages, disadvantages, and chronological development of each breaking technique."

Jan 1, 1998

By M. J. Steffens

ESPLIM is a novel separation technique that combines the advantages of solvent extraction and electrostatic dispersion but its application in the extraction of nickel by the direct solvent extraction route and the effect of high electrostatic field on the stability of organics have not been explored. These were investigated in this study and it was found that the technique allows 97% extraction of the nickel in a single stage compared with 3 stages by the conventional solvent extraction. Also, three months of exposure to 5.0 kV under simulated operational conditions had no adverse effect on the stability of organics.

Jan 1, 2005

By M. Girard, C. Farsangi, N. Singh

"Canadian Royalties Inc. owns and exploits the Nunavik Nickel Project: a copper and nickel deposit in Nunavik, Québec. The nickel and copper concentrates are filtered by plate and frame filter presses, and are transported 100km north to Deception Bay by truck. As the site is situated in the far north, extreme weather can be detrimental to production: roads can close for significant periods of time, resulting in the concentrator using all its storage capacity. During the winter of 2017, this accounted for over 100 hours of unplanned mill downtime. Different solutions to this problem were evaluated and the most economically viable combination of solutions was determined to be the use of concentrate storage containers and upgrading the plate size of the existing nickel filter press. By satisfying new, increased utility requirements, the cycle times would not change, but produce 30% more filter cake. Simulations were developed to determine the number of concentrate containers needed in conjunction with the upgraded press to eliminate unplanned downtime due to road closures and secure production through the winter. This paper summarises these simulations, the commissioning and start-up of the upgraded filter press, container loading procedures, and how this was put together to achieve a record 2018 winter season with a 90 percent reduction in downtime. The payback period of the project was 4 months. A specialised side-tipping trailer emptied the containers during the fall of 2018.INTRODUCTION The Nunavik Nickel Project is a nickel/copper mining project located in Nunavik, Québec. The nickel and copper concentrates are stored in stock tanks after thickening and are then filtered by plate and frame filter presses at the concentrator before being transported 100km to the shipping port at Deception Bay by trucks. The region is prone to periods of extreme weather during the winter, with winds that can reach +100km/hr and blizzards that severely limit visibility. The roads to Deception Bay are often affected by this weather, causing closures that last an average of 18hrs and as long as 72hrs. Additionally, there is a 15% chance that road closures occur within 24hrs of the last event. This has been an issue for the concentrator team since start-up in 2013, causing unplanned mill downtime every winter (Table 1) due to filling concentrate storage capacity during prolonged closures of the roads to Deception Bay."

Jan 1, 2019

By Tim Watson

Andacollo Hypogene Project ?Overview Project description: Sulphide copper concentrator Throughput:55,000 tpd Location: Approximately 50 km from La Serena Elevation: Approximately 1,000 m ASL Start feasibility study: July 2005 Start of construction: May 2007 Construction completion: December 2009 Final cost(1,2,3):435 Million US $ (1) Excludes third party costs, 220 kV power line (2) Cost is based on a Chilean Peso to US Dollar foreign exchange rate of 535 to 1 (3) Does not include US$40.3 million for the Elqui River Pipeline Project or US$8.0 million for the stock pile cover

May 1, 2010