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By Mike Broczkowski, Laura Dewhirst, Kieran Large, Angelo R. Fernando, Heather Daigneault, Jim Johnson, Randy Wiens

The radioactive isotope radium 226 is a contaminant of potential concern in effluent waters from metal mining operations in Canada. Acceptable release levels of radium 226 are governed by Metal and Diamond Mining Effluent Regulations. Since radium is invariably present as a companion element in uranium ore, monitoring and controlling of radium 226 is a must for uranium mining operations. Measurement of radium 226 is traditionally carried out through a radiochemical technique involving selective co-precipitation of radium with barium sulphate followed by alpha spectroscopy for quantification. As of 2010, Cameco has also been using an ICP-MS based radium analysis method developed in collaboration with a research team at Trent University, Peterborough, Ontario. This method, which is highly automated and requires significantly less sample handling, with improved turn-around-times, is being used by Cameco site laboratories at the McArthur River and Cigar Lake mines as well as the Port Hope Conversion Facility. This paper compares the benefits and drawbacks of this new method, compared to the traditional alpha counting procedure drawing from almost ten years of field experience.

Jan 1, 2020

By Atsushi Sainoki

Blast vibration induced by mining activities, such as stope production blasts, could lead to the initiation of seismic events that inflict damage to mine openings. In this paper, the effect of stope production blasts on nearby fault is examined. First, validation of blast vibration attenuation is performed with a numerical model representing a single blast hole through comparison with that calculated from charge-weight scaling law derived from in-situ data. Subsequently, a mine-wide scale model with a fault parallel to a steeply dipping, tabular ore deposit that is mined out with sublevel stoping method is generated, and the stopes are extracted and backfilled with static analysis to simulate burst-prone conditions on the fault. Based on the stress states, dynamic analysis is performed, in which blast vibration is applied to grid points on a stope wall on the hanging wall side. This assumes 9 blast holes located close to the wall, and blast-induced particle velocities that consider the positional relationships between the assumed blast holes and the stope wall are applied. During the dynamic analysis, blast sequence is considered, and stress states and shear displacement on the faults are examined. It is found from results that, after a rise in normal stress on the fault due to compressive waves induced by the blasts, the normal stress decreases because of the reflection of the compressive waves on the fault. The reduction in the normal stress due to the reflected waves is found to be large enough to cause the fault to slip. The results also show that the level of normal stress eventually keeps decreasing with time as the blast sequence proceeds and that an increase in shear displacement on the fault is accompanied by a decrease in normal stress. This study clarifies the mechanism by which blast vibration causes the fault to slip. In addition, the simulation technique to apply blast vibration that takes into account blast sequence and the locations of blast holes to a stope wall is developed.

Aug 1, 2013

By H. Arima, Y. Kudo

In general, the iron content of zinc leach residue produced by sulphuric acid leaching from calcine is disposed as jarosite or goethite into a tailing dam. More recently, these iron residues have been treated pyrometallurgically to avoid waste disposal. The Iijima refinery selected a different zinc leach residue treatment process for iron control when it was established in 1971. The Iijima refinery is the only plant in the world that has processed a zinc leach residue by the combination of SO2 pressure leaching and O2 pressure hematite precipitation. The process enhances zinc recovery and recovers gold, silver, copper, lead and rare metals in saleable by-products. This paper focuses on the two stages of autoclave application in the zinc leach residue treatment process. The detailed flowsheet and recent advancements to improve the quality of by-products are discussed.

Jan 1, 2004

By P. E. Cavanagh

"The Davis tube test has been used for many years as a laboratory method for determining the magnetic iron re-coverable from a magnetite iron orebody. This paper de-scribes a method for determining the recoverable iron from ores of the Labrador Trough type, with the usua1 flow sheet utilizing spirals followed by magnetic separation.The mechanical structure of a metamorphosed iron ore, resulting from recrystallization over long periods of time, is the basis for the laboratory method developed. Similarities between the structures of such recrystallized ores and the structure of annealed and recrystallized steel are noted.A laboratory technique to determine the size of the different grains of gangue and iron ore minerals is de-scribed and the application of this information to arrive at recommended grinding techniques and flow sheets is demonstrated. The use of the method to determine recoverable iron in such ores is compared to actual iron recovery in the pilot-plant and commercial concentrations of the same ore.The use of a specified lower limit of recoverable iron as determined by this method, in order to design open-pit limits, achieves practical results when compared to designing a pit based on an arbitrary lower limit of total soluble iron. The Ungava Iron Ore deposits are used in giving an example of the resulting pit design changes."

Jan 1, 1968

By X. Cao, J. J. Jonas, Wanjara. P., J. Gholipour, E. Dalgaard

The linear friction welding (LFW) behaviour of near-ß titanium alloy Ti-5Al-5V-5Mo-3Cr (Ti- 5553) was investigated. Microhardness measurements were performed in order to evaluate the mechanical properties of the welded material. The linear friction welded (LFWed) Ti-5553 was examined with optical microscopy and scanning electron microscopy (SEM) to evaluate the microstructure’s response to the thermomechanical conditions. Characterization of the welds included analysis of the microstructural features of the weld region and thermomechanically affected zone (TMAZ) in relation to the parent material.

Jan 1, 2010

By T. F. Pugsley, D. Gignac

"The historical background to the project dates back to the mid-30s with the discovery of surface sulphide showings in the Cape Smith-Wakeham Bay ultramafic belt. In the mid1950s, orderly exploration commenced with an extensive work program by Asarco, INCO, Lemoine, Falconbridge and Raglan Nickel Mines Ltd. on exploration permits. In 1966, Falconbridge and Raglan Nickel Mines interests merged. Extensive exploration, drilling, under- ground delineation of the Donaldson orebody and the construction of basic infrastructure such as camps, airfield, road links from Douglas Harbour to Donaldson and Katinniq, a distance of 60 km, were completed.Production project design at that time consisted of plans for a 50 000 mt per year nickel mining and concentrating operation, including a 2000 person community and smelter at Douglas Harbour. These plans unravelled in the mid-70s due to high capital costs, poor nickel market conditions and the realization that the Raglan orebodies were not large enough to economically support the construction of green field smelter and refinery facilities for processing Raglan production. Nickel market conditions in the late 70s and early 80swere generally poor, resulting in further delays on production plans.While recognizing the very high potential to discover increased tonnages of high grade(3% Ni) in excess of 20 million tonnes, the project was deferred into the late 80s when a serious re-evaluation of exploration potential occurred and the requirement to prove up additional reserves resulted in an underground exploration program at Katinniq covering the period 1990-1992."

Jan 1, 1996

By E. L. Chanturiya

The research and characterisation for compositional, physicochemical, structural, electrical and flotation properties of various pyrite samples for a copper-zinc sulfide ore was carried out. Various methods were used during the research, such as optical microscopy, X-ray diffraction, electron probe micro-analysis (EPMA), phase emission analysis, routine chemical analysis, auger electron spectroscopy (AES), scanning electron microscopy (SEM), back-scattered electron images (BSE), potentiometry, and instrumental neutron-activation analysis, flotation. Analysis of obtained results established the interrelation between impurity structures and concentration of electric charge carriers in minerals, Butyl xanthate sorption and flotation yield of pyrite. The research concluded that pyrite samples differ by morphology, micro defects of structure, concentration of donor and acceptor impurities (Co, As, Sb, etc.) and conductivity parameters (thermo-electrical force, specific resistance and concentration of charge carriers The peculiarity of pentagon-dodecahedral pyrite is the high concentration of electric charge carriers (electrons) and the more negative surface potential (by 25–75 mV) in comparison to cubic pyrite. The surface of cubic varieties is more active, therefore it is oxidized in alkaline lime medium much faster, than the surface of pentagon-dodecahedral varieties. This phenomenon is caused by high reaction ability, irregular jointing and defects of cubic pyrite. This promotes the increase of calcium ion sorption on its surface and the decrease of Butyl xanthate sorption. According to this, an increase in alkalinity (lime medium) from a pH of 10.0–11.5 leads to an increase of gold content reporting to the tail of bulk flotation. Gold content is increased from 0.58 g/t (?? 9.5) to 1.9 g/t (?? 11.6), which represents an increase in gold recovery of 24.68 to 79%, respectively.

Jan 1, 2016

By G. F. Vander Voort

Over the past twenty years, steelmakers have introduced improved practices for reducing the inclusion content of steels. The success of these practice changes can be monitored in a variety of ways. Chemical analysis of the bulk sulphur and oxygen contents provides a relatively simple means to assess the impact of these changes. However, microscopical test methods are still needed to assess the nature of the inclusions present. Traditional chartbased measurement methods have wide acceptability, and their data are well understood by both purchaser and producer for heat acceptance purposes. However, these methods do have inherent weaknesses which limit their usefulness for quality control, SPC, and database applications. Image analysis-based chart measurements are an improvement over manually generated chart ratings, but the data still do not lend themselves to databases and statistical comparisons. ASTM Committee E-4 on Metallography has developed a stereologicallybased image analysis standard test method, E 1245, which provides the necessary data in a form which is easily databased and analyzed statistically. This paper describes E 1245 and shows how data from different heats and melting practices can be compared statistically to ascertain valid test differences.

Jan 1, 1998

By S. Nafisi

Permanent mould casting may be regarded as a near net shape manufacturing process where simple to very complex shaped engineering components are fabricated with high degree of precision in a metallic mould, In this group, High Pressure Die Casting (HPDC), have attracted more attention because of its production rate, where both liquid and semisolid metals (SSM) can be cast with high degree of precision and versatility. The SEED process, Swirled Enthalpy Equilibration Device, the new process for semi solid metals slurry production route, consists of two steps: The initial step involves extracting specified amount of heat from the molten metal to generate liquid-solid slurry, i.e, mushy structure, followed by drainage of remaining liquid to produce a compact free standing feedstock for rheocasting operation. In this paper, microstructural evolution during the process and some initial casting results of automotive components an also reported.

Jan 1, 2005

By H. Saeedi Ali, A. J. Monhemius

"Anglo Asian Mining’s Gedabek mine is situated in the Lesser Caucasus mountains in Western Azerbaijan. The ore body is a complex copper-gold porphyry deposit, comprising intermixed oxidized, transition and sulphidic gold and copper-bearing ores. Gold in the sulphide ores is generally not refractory and is recoverable by cyanide leaching, but the secondary copper minerals, which are also cyanide soluble, lead to high cyanide consumptions. Ore processing at Gedabek is by agitation leaching for high grade ore (>1g Au/t) and heap leaching for lower grade ore. In order to cope with the high copper concentrations in the cyanide leach liquors, a unique combination of resin-in-pulp for selective gold extraction and SART processing for copper removal and cyanide recovery is used. In 2015, a flotation plant was added to treat the tailings from the agitation leach plant before the tails are sent to the tailings dam. This plant produces a copper sulphide flotation concentrate and also recovers some of the residual gold and silver in the tailings. Since February 2017, due to lower grades of gold and higher copper in the feed ore, the decision was taken to alter the flow sheet and to carry out flotation ahead of agitation leaching, to reduce the cyanide consumption during leaching by removing soluble copper minerals. The paper compares and contrasts the performance of the plant in the two configurations, namely, (i) leaching followed by flotation and (ii) flotation followed by leaching.INTRODUCTION In May 2009, Anglo Asian Mining started open pit mining for gold on its Gedabek property in the Lesser Caucasus Mountains in western Azerbaijan. Gedabek is situated on the highly mineralized Tethyan Belt that runs from the Himalayas to the Balkans. The ore body at Gedabek is a complex copper-gold porphyry deposit, comprising intermixed oxidized, transition and sulphidic gold-bearing ores. The sulphidic ores contain mainly pyrite and chalcopyrite, with some secondary copper sulphide minerals, such as bornite and chalcocite, and minor amounts of sphalerite, galena and tetrahedrite. Gold in the sulphide ores is generally not refractory and is recoverable by cyanide leaching, but the secondary copper minerals, which are also cyanide soluble, lead to high cyanide consumptions and passivation of free gold."

Jan 1, 2017

By P. Moreno

ABSTRACT: The Maras salt terraces, located between Cuzco and Urubamba in the Andes (southern Peru), are living examples of traditional Incan salt production, where present-day artisanal miners produce salt from shallow pans by solar evaporation. In these terraces, natural spring water, eight to nine times saltier than seawater, is used to produce the salt. The field observations and chemical analyses show that the poorly crystalline traditional salt is finer in particle size and contains impurities such as dolomite and gypsum. These differences are the result of shallow pond depth, contamination from wall erosion, and the nonsequential mode of salt crystallization.

Jan 1, 2011

By A. R. Laplante

Gold recovery early in the flowsheet, typically from the primary grinding circuit, has seen significant advances in the past three years. Some of the advances achieved under the auspices of the AMIRA P420B Gold Processing Technology project are reviewed. The areas covered are gravity-recoverable gold (GRG) characterization, GRG behaviour in classification, gravity recovery simulation and the link between gravity recovery and cyanidation.

Jan 1, 2005

Research on alternative lixiviants for gold is ongoing; however few people have looked at complete flowsheets. Alternative lixiviants are typically applied at concentrations 50 to 100 times those required for cyanidation. The higher concentrations make lixiviant recycle a vital part of the process. In addition it is no longer feasible to rely on lixiviant destruction to produce lixiviant free clean water for recycle to the comminution circuit. Ausenco has worked with Barrick to integrate reverse osmosis into the thiosulfate RIL processing flowsheet that forms the basis of the plant upgrade currently being constructed at Barrick’s Goldstrike autoclave facility.

Jan 1, 2014

By J. E. Udd, L. B. Geller

"Mine-shaft wire-rope discard regulations include, among other criteria, a limited amount of permissible loss-of-breaking-strength (LBS). Currently, this parameter is estimated on the basis of non-destrutive-testing (NDT) with electro-magnetic (EM) type instruments. This paper analyses the accuracy with which these estimates have, so far, been obtained in practice.It concludes that while certain types of testers have produced better results than others, the desired accuracy level has not been attained. Also discussed are the putative reasons for this situation, and appropriate actions that the mining industry might wish to take."

Jan 1, 1990

By M. H. MacLeod

"IntroductionTHE ORE PASS raise system at the H.B. mine as contracted by the Patrick Harrison Company consisted of two raises 6 ft. by 10 ft. in section •at 60 degrees to the horizontal. No. 88-88 raise, the longer of the two, was a straight raise 690 feet long, with access only from the bottom. In addition, this raise had two branch knuckle-backs only one of which was driven by. the Patrick Harrison Company. The other, known as 88-89 raise, was 540 feet long with knuckle-backs at 280 feet and 410 feet. Its access, also, was from the bottom (see Figure 1)."

Jan 1, 1954

By B. Stettner, J. Asante, S. Abraham

The levels of nitrogen in steel produced in various metallurgical vessels vary significantly. For example, the tap nitrogen levels in steel produced in the BOF are around 4Oppm, as compared to 70-100ppm in both DC and AC electric arc furnaces. Given the pressing need to reduce nitrogen levels in steel to satisfy customer demand, IPSCO Inc. has gained considerable experience in controlling nitrogen levels in steel over the course of the last three years. Hence, a cost effective process has been developed through an intensive nitrogen control program from steel melting in the EAF through to the continuous slab casting stage. This paper describes the practices employed at each stage of the steelmaking process that have enabled IPSCO Inc. to reduce and control nitrogen levels in steel.

Jan 1, 2004

By L. Voisin, K. Yamaguchi, D. G. Mendoza, K. Ltagaki

The behavior of arsenic and antimony in the Cu-0 system was thermodynamically investigated to understand their elimination during a blister-making stage in copper smelting. Firstly, the phase relations in a miscibility gap composed of the liquid slag and copper phases in the Cu-0-As and Cu-0-Sb systems at 1523 K were established by a quenching technique. It was found that arsenic and antimony distributed preferentially into the slag phase in the miscibility gap. Secondly, the activities of arsenic and antimony in the miscibility gap of these systems were determined at 1523 K by using a double Knudsen cell - mass spectrometer method. It was clarified that the activity of arsenic in the copper and slag phases showed the negative deviation from ideality while that of antimony in the copper phase a slightly positive deviation. These data obtained in this study suggest a possibility to eliminate arsenic and antimony by means of over-blowing in a converter after discharging the slag.

Jan 1, 2007

By K. C. Hendrick

The paper will review the significant developments in world copper over the past ten years and their impact on the Canadian industry. It will also examine the outlook for the future.

Jan 1, 1971

Pilot plants for pressure hydrometallurgy represent special design and project execution challenges unique to the industry and to the pilot- and demonstration-scale. Pilot plant projects have different objectives and shorter timescales than commercial plant projects. Design considerations and strategies, and project execution methods that meet the special needs of pilot plant projects, are discussed. Specific guidance is given for the selection of appropriate pressure and temperature design points for pressure hydrometallurgical process equipment, and for the selection of materials of construction for pilot-scale equipment. The balance between the need for process similarity with future commercial operations and the realities of pilot-scale equipment is also discussed.

Jan 1, 2004

By Colin Harvey

The paper industry in the Pacific Northwest is a potentially large market for industrial clays. Current trends within the paper industry towards higher quality newsprint, filled and coated papers, offers an incentive for exploration in the region since the current supply of kaolin is mainly from Georgia in the southeastern U.S. Freight rates commonly exceed US$100 per tonne. The kaolin resources of the Pacific Northwest require expensive processing technologies to meet the industry specifications and it is doubtful that any large development of the local resources can be supported at the present time. Competition from high-quality regional resources of carbonates is another factor weighing against the development of local kaolin resources while there is a potential threat from shipments ofAsian and Brazilian kaolin in the early part of the 21st century.

Jan 1, 2001