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By Ben Burger

This paper describes the design, the first three years of operation and optimization of a large, single stage SAG mill at Minera Yanacocha?s Gold Mill facility located in northern Peru. The Gold Mill was commissioned in March 2008 with a 32? x 32? EGL, 16.5MW single stage SAG mill, to process 5 million tonnes per annum high grade oxide Au/Ag ore. Operational control, feed size distribution, grinding media, mill liner, grate and pulp lifter optimisation have allowed the mill to operate 15-30% above design throughput rates, but with a product P80 coarser than design. As part of the optimization, full grinding circuit surveys were conducted. Historical operating data and survey data were analyzed and used to evaluate possible circuit changes and determine alternative operating strategies. A number of changes were implemented which allowed the SAG mill to operate similarly to a large ball mill and achieve finer mill product that was closer to design. This paper summarizes life to date data analysis and improvements made by Minera Yanacocha as well as the grinding circuit optimisation study conducted by Metso Process Technology and Innovation.

Jan 1, 2012

By M. A. Halim, V. I. Lakshmanan

Recycling is one of the key elements for sustainable process development for the recovery of value-added products and reducing environmental impact. Process Research ORTECH Inc. has developed several innovative and sustainable technologies, which minimizes the use of water, and chemicals for the recovery of gold, vanadium and gallium from secondary sources by maximizing the recycling of reagents, and reuse of water from process effluents.

Jan 1, 2015

By Y. Wang, S. Liu, K. Jiang

China is the world’s largest producer and consumer of non-ferrous metals. In recent years, significant progress has been made in research and commercial application of pressure leaching technology to produce some nonferrous metals. Research and development activities include a low-pressure, low-temperature leaching technology for complex copper concentrates, a hematite process to treat pressure leach solutions from zinc concentrates, and a pressure leaching - solvent extraction process for molybdenum and rhenium. Examples of commercial practices include a two-stage pressure leach technology in a zinc plant in Danxia, a direct leaching technology in a zinc plant in Zhuzhou, a high pressure acid leaching process for a nickel laterite project in RAMU, and a pressure leaching technology to treat arsenic sulfides in a plant in Guixi. The development of pressure leaching technology for the recovery of lead, vanadium, gallium, germanium, and precious metals in China will also be described in this paper.

Jan 1, 2015

By W. Abdellah

Underground mine developments, such as haulage drifts and cross cuts, play a vital role in providing access to ore extraction areas for mine production. The stability of mine developments is thus of crucial importance during the life of a mine plan. Many Canadian mines use longhole mining methods or one of its variants. These methods require access to the orebody through mine developments such as haulage drifts and cross cuts on multiple levels. This paper examines the stability of mine development access intersections with respect to the planned mining sequence. A case study, the #1 Shear East orebody at Vale?s Garson Mine in Sudbury, Ontario, is presented. A three-dimensional, elastoplastic, finite difference model (FLAC 3D) was created for a development intersection situated 1.5 km below ground surface. The stability, or performance of the intersection, is evaluated in terms of the strength-to-stress ratio. The ratio threshold is set at 1.4 for temporary openings. Unsatisfactory performance is defined as a strength-to-stress ratio less than this threshold value. The performance of the intersection stability is evaluated at various modelled mining stages and the probabilistic method of analysis is then invoked to study the probability of unsatisfactory performance of the intersection. The results are presented and categorized with respect to probability, instability, and mining stage.

Aug 1, 2013

By D. L. Koch, J. W. Tester, L. K. Sinclair

"In this study, hydraulic conductivity (K) geostatistics were used to predict residence time distribution of well-to-well flow. Flow profiles, fracture density measurements, and pumping tests were available from the highly fractured Florence Copper in situ leaching site. The flow profiles were used to establish the statistical distribution and spatial autocorrelation of K. Two tests were used for validation. The first test confirmed that fracture density and K are autocorrelated over similar length scales. In the second test, Monte Carlo flow simulations successfully recreated the results of pumping tests. Flow sim¬ulations were used to stochastically model well-to-well residence time distribution. RÉSUMÉ Dans cette étude, nous utilisons la géostatistique de la conductivité hydraulique (K) pour prévoir la distribution des temps de séjour (DTS) de l’écoulement entre les puits. Des profils de l’écoulement, des mesures de la densité des fractures et des essais de pompage existaient pour le site fortement fracturé de lixiviation in situ de Florence Copper. Les profils de l’écoulement ont permis d’établir la distribution statistique et l’autocorrélation spatiale de K. Deux essais ont servi à la validation ; le premier a confirmé que la densité des fractures et K sont autocorrélés sur des échelles de longueur similaires ; quant au second, des simulations d’écoulements de type Monte Carlo sont parvenues à reproduire les résultats des essais de pompage. Les simulations d’écoulement ont servi à établir un modèle stochastique de la DTS de l’écoulement entre les puits.INTRODUCTION In situ leaching is the circulation of a dilute acid or base solution in the subsurface, via a series of injection and recovery wells, to dissolve a target metal. In situ leach modelling requires forecasting the residence time distribution (RTD) of flow between wells. In fractured formations such as copper porphyry deposits, order-of-magnitude variations in hydraulic conductivity (K) can result in highly channeled flow, resulting in a heavy tailed RTD (Becker & Shapiro, 2003; Kang, Le Borgne, Dentz, Bour, & Juanes, 2015). Channeling through preferential pathways has impacted copper recovery at several past in situ leaching field tests (Cathles, Glenn, Lenzi, Nigrini, Deans, & Huff, 1978; Ahlness & Pojar, 1983; Schmidt, Earley, & Friedel, 1994; Sinclair & Thompson, 2015). The aim of this work is to combine multiple types of hydrogeological measurements to stochastically forecast the well-to-well RTD in fractured rock for the purposes of copper in situ leach modelling."

Jan 1, 2018

By T. Majcherczyk

Shaft lining reinforcing analysis of two shafts under construction has been presented in this study. The first shaft was driven from the surface, while the second was deepened. Mining and geological conditions have been studied with respect to the lining capacity. The improvement of shaft stability comprised two elements, i.e. reinforcement of the shaft lining capacity and improvement of the strength properties of the rock mass. In both tested cases, the particular hazard was connected with non uniform loadings of the lining, which could generate shearing stresses within lining structure. Thus such elements as armored concrete with high strength properties, bolting and injection sealing of the rock mass, and the use of special ring reinforcing the shaft lining have been used in order to reinforce the shaft-rock mass system. Practical conclusions related with new technological solutions, allowing the rock mass and shaft lining reinforcement, have been included for the present study. Practical conclusions related with new technological solutions, allowing for rock mass and shaft lining reinforcement, have been also included to the present study.

Aug 1, 2013

By Taisuke Sakakibara, Shinya Suzuki, Tatsuya Kato, Chiharu Tokoro, Kenichi Muto

Surface complexation using a diffuse layer model were constructed for arsenic (As(V)), zinc (Zn(II)) and silicate (Si(IV)) for aluminum hydroxide in the co-precipitation process. From experimental investigations using isotherms, zeta potential measurement and XRD analysis, it was confirmed that co-precipitation involved not only surface complexation but also surface precipitation. However, surface complexation was major mechanism for As(V), Zn(II) and Si(IV) removal under the target removal level of the Japanese effluent standard. In surface complexation modeling, exchange capacity of aluminum hydroxide was determined from specific surface area obtained from experimental measurement and site density obtained from reference. Surface complexation coefficients were determined by fitting the removal property and sorption isotherm obtained from co-precipitation experiments. These parameters were in agreement with the numerical parameters found by Karamalidis and Dzombak (2010) who reported a database of adsorption equilibrium constants for gibbsite. The surface complexation models constructed in this study were applied to neutralization process of an actual AMD treatment. Our model could successfully represent the pH edges for As(V), Zn(II) and Si(IV) in the neutralization of AMD.

Jan 1, 2015

By Peter M. Power

A microscopic study was made of a series of simultaneous slag and metal samples taken from a low carbon basic open hearth heat. An attempt was made to identify the various micro-constituents found. As the various impurities in the bath are oxidized, the metal structure changes from that of high-phosphorus white cast iron to that of low.-carbon steel. A detailed study of phosphorus distribution is included. The acid run-off slag has an .acicular orthosilicate structure which changes on 'shape-up' to a very basic tri-calcium silicate and calciuim ferrite structure. Many unidentified minor constituents are present in the slags. Though metallography will never replace chemic.al analysis of the bath, the microsopic study of polished slags has some promise of being useful in slag control work.

Jan 1, 1956

By W. A. Gow, G. M. Ritcey, M. C. Campbell

"Uranium is a unique commodity. It is both a metal and a fuel, It has both commercial and military uses. It yields ""clean energy "" but presents environmental concerns. All of these factors have an impact on the commerce of uranium.Being a metal, uranium is extracted from ore like many other metallic minerals. As a fuel, it is subject to the vagaries of energy commodity market forces. The history of uranium in the first nuclear weapons has led to nation al governments carefully controlling production and sale of uranium. The spectre of radioactive contamination of the environment adds further to the public concern over the disposal of low-level radioactive wastes from uranium processing and use.There have been a number of excellent reviews on the commercial aspects of the uranium industry. In this discussion, these aspects will be briefly summarized to provide a general picture of the strengths of the Canadian uranium industry and the pressures to which it is being subjected currently. The principal thrust of this paper will be to outline Canada's resource strength and to identify some factors which will affect Canada's ability to continue holding a sizeable share of the world uranium market."

Jan 1, 1985

By C. Butcher

Numerical simulations of straight tube hydroforming of a dual phase steel were performed using both upper and lower bound constitutive models for porous ductile materials. The Gurson model is based upon an upper bound approximation to the material behavior and thus overestimates formability. Conversely, a lower bound solution to Gurson's unit cell geometry was developed by Sun and Wang to provide a conservative estimate of formability. The effect of a compressive axial load (end-feed) on damage development and tube formability is investigated. The resulting upper and lower bound models successfully captured the experimentally determined burst pressure, formability and failure location.

Jan 1, 2010

By M. Laframboise, M. Buarzaiga

High-pressure acid leaching (HPAL) of nickel laterites has received considerable attention in recent years. High paymetals extraction, good selectivity, and advances in pressure hydrometallurgical technology are some of the reasons for this interest. Falconbridge Limited (Sudbury. Ontario) investigated the HPAL process using both fresh water and seawater for ore processing. The use of seawater resulted in a chloride concentration of 7.8 g/L in the autoclave feed. A test program was developed to study the effect of process water and leach temperature on the leaching behaviour of different ore compositions from the Koniambo deposit in New Caledonia. The work showed that salinity has a major effect on autoclave chemistry. This paper explores the results.

Jan 1, 2004

By L. V. Chugaev, Y. M. Shneerson, P. V. Zaytsev, I. V. Fomenko, M. A. Pleshkov

"Pressure oxidation (POX) is one of the most common and reliable methods of processing gold-bearing sulfide concentrates. However, when processing concentrates that contain natural carbonaceous matter, substantial gold losses occur due to autoclave preg-robbing. The latter involves formation of gold chloride complexes under typical POX conditions (high temperatures, high acidity and high ORP) and subsequent sorption of these complexes by carbonaceous matter. Naturally, chloride ion plays a significant role in the process of autoclave preg-robbing; its concentration in POX solution has a well-marked effect on subsequent gold recovery during cyanidation of POX residue. The previous research done by SRC Hydrometallurgy showed that autoclave preg-robbing of gold could be significantly inhibited by the addition of mercury(II) compounds to POX slurry. The positive effect of mercury(II) was well pronounced both at high (>20 mg/L) and low (<5 mg/L) Cl concentrations in POX solution. The successful bench-scale laboratory testing was followed by pilot plant trials at Ore Test Facility in Blagoveshchensk, Russia. The present paper provides the results of these trials. The bench-scale testing results were verified; the optimum oxidizing parameters and reagent dosage were specified. The behavior of mercury (II) at POX pilot plant was found to be in good consistency with industrial practice described in the literature.INTRODUCTION Pressure oxidation (POX) is one of the most common, reliable, and commercially proven methods of processing gold-bearing sulfide ores and concentrates. However, when processing double refractory materials that contain natural carbonaceous matter, POX technology advantages are compromised by autoclave preg-robbing of gold. The latter occurs when natural organic carbon and soluble halides are both present in autoclave feed. Strongly oxidizing conditions of POX (high temperature, oxidation-reduction potential or ORP, and acidity) favor formation of gold-halide (mostly, gold-chloride) complexes, which tend to bond with carbonaceous matter. The exact nature and mechanism of this bonding is unknown, but as the result of this, cyanide is unable to leach gold from POX residue and the precious metal is lost to the tails (Axenov et al., 2014; Dimov, Chryssoulis, & Sodhi, 2003; Fomenko, Zaytsev, Pleshkov, Chugaev, & Shneerson, 2013)."

Jan 1, 2017

By Qingxia Liu, Mingbo Zhang, Hongbo Zeng

The shortage of freshwater has been a major challenge for mineral flotation in arid areas. When using high salinity water, certain electrolytes are detrimental to flotation while others can improve the flotability of minerals. In this paper, the flotation behaviors and contact angles of pyrite in both Milli-Q water and high salinity water were investigated using different collectors at various pH levels. Results show that the thionocarbamate has a less affinity to pyrite in different solutions under mildly alkaline conditions as compared with potassium amyl xanthate (PAX) and N-isopropoxypropyl-N’-ethoxycarbonyl thiourea (iPOPECTU). At high pH levels, the slime coating on pyrite surfaces, which is caused by colloidal precipitates of magnesium and calcium ions in seawater, was confirmed by SEM, EDX and in-situ zeta potential measurement. The slime coating of colloidal precipitates on mineral surfaces led to low recovery of pyrite at high pH levels. The study of flotation behavior of pyrite in high salinity water improves our fundamental understanding of mineral flotation in seawater.

Jan 1, 2015

By Guoqiang Lan, Jun Song, Bin Ouyang

Rare-earth pyrochlores, commonly exhibiting anomalously low lattice thermal conductivities, are considered as promising topcoat materials for thermal barrier coatings. However the structural origin underlying their low thermal conductivities remain unclear. In the present study, we investigated the phonon properties of a group of RE pyrochlores, Ln2Zr2O7 (Ln = La, Nd, Sm, Gd) employing density functional theory and quasi harmonic approximation. Through the relaxation time approximation (RTA) with Debye model, the thermal conductivities of those RE pyrochlores were predicted, showing good agreement with experimental measurements. The low thermal conductivities of RE pyrochlores were shown to largely come from the interference between the low-lying optical branches and acoustic branches. The structural origin underlying the low-lying optical branches was then clarified.

Jan 1, 2015

By H. S. Wilson

"The property owned by the Lamaque Mining Company comprises a group of forty-four claims and fractions occupying an area of about 2,458 acres, in west-central Bourlamaque township, Abitibi county, Quebec. It is on ,the outskirts of the towns of Bourlamaque and Val d'Or, about 70 miles east of Noranda, near the eastern end of the belt of greenstones of Keewatin and Timiskaming age that extends eastward through Kirkland Lake into northwestern Quebec, terminating in Haig and Jurie townships 40 miles to the east.The claims on which the orebodies occur were first staked in 1923; No. 3 vein was discovered the following year. The original discovery was made by R. Clark in 1923. This was a small quartz vein containing a pocket of coarse gold on the north side of a hill near the northwestern corner of block 3. It is said that all the gold was removed in one shot in blasting into the vein; elsewhere it was barren. A picket line was then run west along the strike of the vein, which occupied a narrow shear zone, and about 2,000 feet west, in prospecting on either side of the picket line, a large boulder of quartz and tourmaline containing visible gold was found. This led to more intensive prospecting by trenching in the vicinity with the result that the No. 3, or 'float' vein, about 250 feet north of the boulder, was found. Due to low ground this vein was exposed in only one trench. The only other important vein found on the surface was the No. 1, or H, vein, which was exposed in several places by stripping and trenching, but it did not carry appreciable amounts of gold."

Jan 1, 1954

"Accelerated expansion of Western Canada's metallurgical coal industry has again stimulated considerable exploration activity in the Rocky Mountain Foothills Belt and influenced much of the R&D related to transportation, processing and carbonization. Preparation R&D has included further pilot-plant work on desulphurization, spherical agglomeration and modified compound cyclones (which are also proving themselves in other mineral beneficiation studies). Combustion research, aside from increasingly stressing control of combustion source pollution, has directed special attention to lignite PF firing and problems arising from lignite ash. Studies directed toward the non-fuel utilization of coal have centered on such diverse topics as active carbons, carbonaceous filter media, plant nutrients and industrial applications of humic acid derivatives. In addition, a number of long-range research projects related to such matters as coal chemistry and pyrolysis have been actively pursued, and further attention has been given to improved sampling techniques and analytical methods."

Jan 1, 1969

By N. H. Grace

"IntroductionDURING the past half century, the economy of Western Canada was largely centred on agriculture. However, the impact of World War II has led to an acceleration in the development of a variety of natural resources so that, today, Western Canada is experiencing great industrial development. Consequently, the availability •of low-cost energy assumes prime importance. In the final analysis, industrial growth and expansion are intimately linked to the energy resources.Coal ReservesHas Western Canada adequate coal reserves to meet the present accelerating demand for power in the days that lie ahead? This question must be answered before detailed consideration can be given to the probable patterns •by which various energy sources in Western Canada may be expected to meet the expanding demand. Figure 1 indicates the extent and distribution of the Canadian coal reserves, the data having been prepared by Dr. B. R. MacKay for the Royal Commission on Coal in 1946 (1). The amount of readily recoverable coal is listed as one-half the quantities shown on the chart. It is interesting-to note that upwards of 90 per cent •of the Canadian coal reserves .are located in the three most westerly Canadian provinces. It has been estimated that the coal reserves, at the present rate of mining, would be adequate for about 3,000 years. Consequently, it may be concluded that the coal •reserves in Western Canada •are indeed adequate to meet tremendous energy demands for many centuries. When the oil and natural gas have been exhausted, the great coal reserves will still be available."

Jan 1, 1953

By J. Visman

"The Compound Water Cyclone is a concentrator for the wet processing, in bulk, of finely divided materials such as slack coal, fine ores and mineral sands. It was originally developed by the Fuels and Mining Practice Division of the Mines Branch, Department of Mmes and Technical Surveys, Ottawa, for the cleaning of friable slack coals and slurries.Since its introduction in the coal industry in 1962, its application to other materials has also been studied, with special emphasis on simplicity of operation and low over-all cost per ton of finished product .In this paper, a description is given of commercial two-stage units presently available for the processing of granular materials, including wastes a1:1d other low-grade products. A pneumatic control system is used for operating the cyclone under back pressure .and for automatic cut-point adjustment. An account is given of results obtained on coal mineral sands and ores in the Wes tern Regional Laboratory of the Department of Mines and Technical Surveys. Results of several industrial applications are discussed."

Jan 1, 1966

By G. H. Gale, M. A. F. Fedikow, L. B. Dabek

Abstract-Rare earth element (REE) data are reported for ores, sulfide-bearing rocks and host rocks from massive sulfide deposits and barren sulfide facies iron formations in Proterozoic volcanic rocks of the Flin Flon-Snow Lake area, Manitoba. Some of the rare earth elements (e.g., Eu), are selectively leached in zones of intense alteration and redeposited together with the sulfides and silicates in the uppermost parts of the alteration zones and at the rock-water interface. Chondrite normalized REE profiles of layered sulfide ores and exhalites proximal to the deposits typically have positive europium anomalies and are enriched in light REE. In contrast, barren sulfide facies iron formations exhibit negative or ‘normal’ Eu profiles. REE data are useful to explorationists in determining the presence of ‘off-hole’ metal-bearing sulfide zones, in distinguishing metal-poor sulfidic layers related to ‘economic’ hydrothermal activity from barren sulfide facies iron formation and in some instances as a means of establishing ‘ore-equivalent’ strata.

Jan 1, 1997

By Gordon Jackson

"There are two accomplishments of air and gas drilling: a new series of economic and mechanical challenges; and, acceptance as a standard drilling and completion tool.The new challenges are related to the concept of using a gaseous circulating medium in drilling for oil or gas. For purposes of discussion, a two part division has been made: the challenge of fluid invasion control and that of equipment and tools. Great strides have been made in the development of materials and techniques to combat formation fluid invasion. Chemicals and the ""mist drilling"" technique, now in use, have the versatility to cope with a wide range of downhole fluid entry conditions.Equipment and tools have been developed to meet the challenges of better, more economic drilling and completion possible with a gaseous circulating fluid. Economic and operational challenges remain.Acceptance of air and gas drilling as a normal operating tool was reached with difficulty. It is now established as a means of reducing costs in exploratory and develop-mental well drilling, exemplified in a recent study of 226 wells covering 419,407 feet of hole in the United States. Air reached the projected depth in 85 per cent of the operations, although formation water was encountered in 48.7 per cent of the holes. Slim hole bit performance and cost all compared for overall bit averages as part of analysis."

Jan 1, 1961