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By G. Scott Zimmer

Mine planning at Cassiar consists of an annual cycle of projection, control, evaluation and revision following completion of annual diamond drilling during the summer months . The inherent difficulty in evaluating fibre grade and distribution, combined with a high-wall phase or push-back mining system, requires continuous modification to designs and schedules based on a cumulative evaluation of equipment performance and prediction versus production. To expedite the planning sequence, a mini-computer system has been introduced which allows emphasis to be placed on optimizing designs, exempting personnel from manual calculations and tabulations.

Jan 1, 1978

By T. V. Lord

Minerals containing uranium have been successfully pre-concentrated by flotation at Queen's University, Kingston. In particular, uraninite, uranothorite, euxenite, and fergusonite, have responded to flotation to yield grades of 0.2 to 6.0 .per cent U .o. with recoveries of 85 to 98 per cent, from heads analysing approximately 0.10 per cent U3Os. Of the ten or so radioactive samples examined to date, two distinct groups were recognizable, firstly, those samples in which uranium was the sole constituent of economic interest, and, secondly, those in which Columbium (with minor amount of tantalum) was present in addition to uranium. For the purpose of this paper, the results of investigation on two samples of each of the above groups have been selected as typical.

Jan 1, 1945

By L. Xia, B. Hart, G. Gingras, M. Furlotte

Plant and laboratory test work was performed in order to optimize a copper/zinc flotation separation circuit at Matagami concentrator, Canada. The testing identified a significant difference between the laboratory testing and the plant flotation, particularly for the sphalerite recovery in the rougher copper concentrate. Tests indicate that sphalerite recovery of the flotation concentrate in the laboratory testing was significantly higher than in the plant. The ToF-SIMS surface analysis identifies surface species responsible for the discrepancy in Zn recovery. It shows that sphalerite flotation is in response to the collector attachment and a significant enrichment of Cu on the surface of sphalerite grains. A comparative surface chemical analysis was performed on both sphalerite and chalcopyrite grains from the plant flotation and laboratory testing in order to identify surface species variability between the two testing. Two significant observations were revealed. First, there is considerably more hydrophilic iron oxyhydroxide on sphalerite surface from the plant flotation sample relative to those from the lab testing. The secondary coating likely completely or partially passivates sphalerite surfaces, reducing Cu enrichment and hence sphalerite floatability. Secondly, comparing the surface chemistry on sphalerite and chalcopyrite, the hydrophilic iron oxyhydroxide species have preference for the sphalerite grains relative to chalcopyrite. Despite numerous studies on the effect of galvanic coupling during grinding, there is limited documented evidence on the effect of the milling environment on the flotation and plant operations. This observation suggests that interaction between sulphide minerals and grinding media have a significant influence on subsequent flotation. This paper discusses the results of a detailed surface chemical evaluation of sphalerite grains from both the plant and laboratory testing in the context of grinding environments and pulp chemistry.

Jan 1, 2016

By I-H. Jung, J. Kim

"Mg alloys are extensively used as light structural materials in modern industry. Mn and RE (rareearth) metals are effectively used as alloying elements to enhance the properties of Mg alloys. Therefore, the thermodynamic database of those alloys is important in the Mg alloy design and processing. Critical evaluation and optimization of all available literature data for the Mn-RE systems were conducted to obtain reliable thermodynamic functions. The Mn-RE systems shows systematic changes in the phase diagrams and thermodynamic properties with increasing atomic number in the lanthanide series. This systematic approach for all RE elements allows to resolve inconsistencies in the available experimental data. INTRODUCTIONRare Earth (RE) metals are widely used in many industrial fields including permanent magnet, electronic materials and structural materials. As a small addition of RE can enhance magnetic, electronic, optical and mechanical properties of numerous materials, the usage of the RE is still expanding regardless of the strategic control of their supply.Magnesium alloys are getting great scientific and industrial attention as the lightest structural materials. One of the drawbacks of Mg alloys is their poor formability at room temperature due to the limited slip system with hcp crystal structure. Recently, several studies (Farzadfar et al., 2011; Sandloebes et al., 2010; Stanford, 2010; Stanford et al., 2008; Yan et al., 2010) show that the additions of small amounts of RE can considerably enhance the ductility of Mg alloys. Therefore, a lot of research on Mg-RE alloys is undergoing to clarify the role of RE on the enhanced deformation mechanism and to find out the most optimum Mg alloy compositions. In order to respond to the need of Mg-RE alloy development, a large thermodynamic database for Mg alloys containing RE has been developed with critical systematic analysis and optimization of the entire RE series data. This includes the thermodynamic database of the Mg-RE (Kang et al., 2009), Mg-RE-RE (Kang et al., 2009), Mg-Al-RE (Jin et al., 2011; Jin et al., 2010), Mg-Zn-RE and Mg-Mn-RE systems."

Jan 1, 2012

By H. O. Lien

Among the known iron deposits in Canada, many are of low grade and require beneficiation to produce an acceptable blast-furnace feed. Some of the deposits have never been considered for commercial exploitation due to the lack of a suitable concentrating process. A number of deposits of this type are located in Northern Ontario. The problem in upgrading these deposits is three fold. Firstly, the iron occurs as a mixture of magnetite and hematite. Secondly, the grain size of the material can be fine to very fine. Thirdly, the complex mixture of gangue minerals, which consists invariably of silica, flaky silicates and carbonates, slimes excessively on fine grinding. Algoma's efforts to concentrate these iron-bearing materials culminated in the development of a "Selective Flocculation and Desliming Process" employing slimes removal as the sole beneficiation technique. The process was applied successfully in the laboratory using two stages of grinding and a total of seven deslimings. Prior to the removal of slimes, the iron-bearing fines were selectively flocculated from a thoroughly dispersed pulp using a modified starch as flocculant, Sodium silicate was employed as dispersant. An attempt was made to optimize some of the process variables using material from one specific iron formation near the town of Geraldton in Northern Ontario. The preparation of the starch proved most critical. This matter, and the method used to evaluate the degree of breakdown of the starch molecule, are therefore discussed in some detail.

Jan 1, 1978

By K. Thuro, H. Käsling, F. Menschik

"With increasing data volume, due to enhancing requirements for ground investigation programs for large construction projects, the demand for more efficient filing systems is more and more growing. Depending on the project we also have to use flexible systems to cope with varying data out of different lab and field tests.The chair for Engineering Geology at TUM is developing a web-based database solution to handle all project relevant data in a more appropriate way. We aim to optimize our data management to achieve a fast and easy way of collecting, documenting and analyzing our gained data. The second objective is to provide an easy access to our data for project partners across broadly distributed locations.This Database system consists of a PHP web interface and a MySQL database core. The current setup allows an online access via Internet (www). We are able to grant and constrain access to all data or only arrays of data with our user management system to guarantee the safety of project data and respect all rights and proprietorship. The database system is of modular design and consists of the following three base modules: module of general project data, module of laboratory data and user management module. At the current stage we are able to save and work with all usually generated specific values from unconfined compressive strength tests, brazilian tensile strength tests, point load tests, CERCHAR and LCPC abrasivity tests and ultrasonic tests. The user is able to perform a simple statistical analysis within our database (e.g. average calculation of one sample) and export data as csv or xls files for further analysis.For specific questions within projects we are able to deploy and integrate further modules in our database system. At this moment, we are developing an add on to use this database for different drill test analyses. One of the tools correlates drilling performance and drill head wear measured in the field with rock mechanical properties, and extrapolates the data to estimate the performance and wear in new projects. Today we are managing 90 projects with 550 samples and almost 1350 lab tests with the base module.In our contribution we aim to demonstrate an efficient way of data structuring using a relational database for laboratory and field testing data."

Jan 1, 2015

By M. Turek

Cost management in the conditions of increasing competition and unforeseen market turbulence constitutes one of the key areas of the enterprise?s activity. In the last two years the demand for hard coal on the domestic and global market of non-renewable resources has increased significantly. Polish hard coal mining industry, as an industry in the stage of decline, received a chance for rejuvenation. However, one of the most significant conditions of seizing this opportunity is the rationalization of mining costs and improvement of production effectiveness. Due to the significance of this issue, the main objective of the paper is to identify the possibilities of improving the production effectiveness in the hard coal mining industry. In order to meet such an objective, in the first part of the paper we measured effectiveness in the Polish hard coal mines in years 2006- 2011. The research encompassed three out of five mining enterprises operating in the country. Then based on the received results, guidelines concerning the improvement of effectiveness of production were created, taking into consideration infrastructural, technical, economic and organizational determinants. Furthermore, opportunities and threats for improving the production effectiveness, stemming from the external conditions have also been indicated.

Aug 1, 2013

By Z. Jun, L. Kerning

Jinlong copper smelter and refinery, originally designed for 100,000tpa primary copper and started up in 1997, has been expanding its capacity on the basis of operational optimization and by modifying its facilities. Currently it is producing 210,000tpa primary copper, and the new phase of expansion project with a target capacity of 350,000tpa primary copper is ongoing. This paper reviews problems and improvements made with operation and equipment in the past years. Recent plant operation is briefly described. The expansion projects completed are summarized and the ongoing expansion project is present.

Jan 1, 2007

By Y. Chunhua, L. Chunsheng, W. Sheng

"Countercurrent solvent extraction is the dominant industrial rare earth separation method. For the rare earth separation, with low separation factors and multiple components, designing and optimization plays an important role in reaching product quality and reducing separation plant costs. Based on the theory of countercurrent extraction, cost-efficient methods, such as third-outlet separation and hyperlinked extraction processing, have been introduced following computer simulation. The consumption and fixed investment of industrial practice are compared, by which advantages of the optimized rare earth separation process are indicated. INTRODUCTIONThe rare earths (RE) have outstanding optical, magnetic and electric properties in advanced material applications and have therefore received much international attention in recent years. Liquid-liquid extraction is the major industrial RE separation method and is widely used in the industry. Supported by the government and with collaboration from the institutions and enterprises, China has made great progress in RE separation, and has become the dominant supplier of separated RE products. Complicated by multiple elements and low separation factors, careful design of RE separation processes is vital for the quality and cost of production. The theory of separation is the key to basic of flowsheet design and industrial applications.BASIC SEPARATION PROCESS AND THEORYGeneral ProcessAcidic extractants such as P507, P204 and naphthenic acid, are the most popular extractants in modern RE separation industry. In the general separating process, the extractant is saponified with a base, then ion-exchanged with RE solutions, thereby to provide stable and high RE loading in the extractant to fulfill the requirement of production quantity and quality. The RE-loaded extractant is then countercurrently extracted and scrubbed with RE solutions and the RE element thereby is purified. After the countercurrent extraction process, the RE-loaded extractant is stripped with acid to obtain an aqueous RE product, and prepare the extractant for recycling (Xu, 1995)."

Jan 1, 2012

By Michael S. Moats, Prashant Bagri

"In recent years with increasing concerns about energy consumption in hydrometallurgical processing, there is an ongoing attempt to use Catalytic Titanium Anodes (CTAs) for copper electrowinning. For this work, anodes with IrO2 - Ta2O5 coatings were prepared in the laboratory with the same total coating loading but varying the number of layers by changing the speed of withdrawal in dip coating. A second set of CTAs were fabricated on niobium, Ti Grade 1, Ti Grade 7 and Ti Grade 36 metal substrates. All the anodes prepared in the laboratory were characterized using standard electrochemical techniques and subjected to accelerated life testing. It was found that the coating would not adhere to the niobium substrate, the grade of titanium had a minimal to no effect on the life of the anode, and it is observed that as the coating speed slows, there is an increase in the electrochemically active surface area of the coating which seems to directly contribute to an increase in the Tafel slope of the anodes. There was inconclusive evidence on the effect of coating speed on anode lifetime.INTRODUCTIONLarge scale hydrometallurgical extraction of copper has become widely practiced over the last 40+ years. The hydrometallurgical route entails leaching, solvent extraction and electrowinning. With the increasing desire to process refractory sulphides like enargite and chalcopyrite through the hydrometallurgical route, use of hydro-processing of copper is expected to remain high.In conventional electrowinning, copper is deposited on the cathode and an inert anode is used for oxygen evolution. Presently, the most common anode material is rolled lead-calcium-tin and the cathode is 316L stainless steel (Robinson et al., 2013). This lead alloy is fairly inexpensive and is robust, providing lifetimes typically of 4+ years. The main drawbacks of lead alloys are their relatively high oxygen evolution overpotential, the need for cobalt in the electrolyte to reduce their corrosion, the contamination of cathode product by lead, and the generation of harzardous by-products (Hiskey, 1999)."

Jan 1, 2016

By L. Magne, M. Maldonado, R. Varela

Real-time optimization of flotation circuits demands for accurate and reliable measurements to support the decision making process. The collection zone gas holdup is an important variable in this context as integrates the effect of machine and chemical factors on the bubble size and velocity distributions. It has been demonstrated that gas holdup not only correlates with bubble surface area flux, which defines the particle collection rate and recovery in the collection zone, but also with water overflow, a variable which has been related to the froth zone recovery. Therefore, on-line gas holdup measurements provide a reliable alternative to judge efforts leading to the optimization of flotation cells and columns. Estimation of gas holdup in flotation from electrical conductivity measurements has been proposed and extensively used in lab and industrial installations. The approach is based on the application of Maxwell's model, which relates the concentration of a dispersed phase in a continuous medium to measurements of the conductivity of the liquid medium and of the mineral pulp with and without air bubbles included. These measurements require a conductivity cell which covers a representative volume of the flotation cell, and creates a homogeneous electric field throughout this volume that ideally is not affected by the conductivity of the medium. The development of such a cell in the limiting space and geometry of a laboratory flotation cell has been problematic, but a multi-electrode arrangement offers a promising alternative. Electrodes were installed in the flotation cell of a Denver unit; the results of preliminary testing are discussed with a focus on its performance in the measurement of two- and three-phase dispersion conductivity.

Jan 1, 2015

By Xiong Tong, Jiushuai Deng, Yingbo Mao, Lingyun Huang

Ammonium carbamate has been used as a reagent for the leaching of copper from the copper oxide ore found in the Honghe state, Yunnan province, China. In order to find the optimal conditions for the leaching of copper from this copper oxide ore,the effects of several processing parameters, including the concentration, time, temperature, particle size and stirring intensity have been investigated. The results of these optimization experiments showed that the leaching rate of copper reached up to 72.76% under the following conditions: liquid-to-solid ratio of 10:1, ammonium carbamate concentration of 2.5mol/L, leaching temperature of 45 °C, stirring speed of 300rpm, a reaction time of 1.5 h and 85% by weight thereof passes through a sieve having 0.074 mm.

Jan 1, 2015

ABSTRACT Based on mineralogical characteristics and processing techniques required, gold ores can be classified into 12 types: gold placers, quartz vein-lode ores, oxidized ores, silver-rich ores, iron oxide copper-gold ores, porphyry copper-gold ores, iron sulphide ores, arsenic sulphide ores, antimony sulphide ores, bismuth sulphide ores, telluride ores, and carbonaceous sulphide ores. The bulk mineralogy and gold deportment of each ore type differs and may have a significant impact on ore processing and metal extraction. This paper summarizes the bulk mineralogy and gold deportment in some major types of gold ore and discusses the potential impact of gold deportment on gold metallurgy.

Jan 1, 2013

By J-F. Magnan, M-A. Thibault, R. Boulianne, C. Gauthier, J-P. Gagné, G. Dufour

During the production of aluminium in smelters, the anodes used in electrolysis cells have to be replaced frequently. Anode butts are usually placed on anode trays for transportation and cooling, a practice during which Hydrogen Fluoride (HF) is emitted in large quantities. Covers developed in 2000 by Alcoa Deschambault to fit on the anodes trays were implemented, resulting in significant reductions of HF emissions. However, the covers are expensive to maintain and use short-life consumable parts. In January 2004, STAS and Alcoa decided to develop a more efficient design of cover, with lower maintenance costs and no need for consumable materials (like soft cushions). This paper presents a summary of the work performed to develop the new design as well as a summary of the test results.

Jan 1, 2006

By S. G. Enns, E. W. Yarrow

"Situated about 200 km southeast of Juneau, Alaska, within the lower Stikine River region of northwestern British Columbia, the Galore Creek porphyry Cu-Au deposits are hosted by Upper Triassic to Lower Jurassic alkaline volcanic rocks and comagmatic syenite intrusions. Early and late breccias are also locally important host rocks for mineralization. Of the twelve identified Cu-Au deposits, the most important are the Central zone, Southwest zone and the Junction deposits with a combined resource of 284 million tonnes at 0.67 % Cu.The composition of the intrusive rocks is predominantly silica-undersaturated, alkaline, and metaluminous. Four intrusive suites are identified from field, petrographic and petrochemical data. Variation within suites or lineages can be explained by alkali feldspar fractionation. An oscillation between porphyritic and equigranular intrusions is suggested by the sequence of different intrusive lineages. The youngest intrusive phase is silica-saturated.A complex succession of intrusive and hydrothermal events is demonstrated at Galore Creek, with the most intense alteration and mineralization developing early in its history. In the Central zone, early Ca-K-silicate alteration, dominated by garnet, biotite, Kfeldspar, and anhydrite grades outward into K-silicate alteration. Both are locally overprinted by retrograde sericite± anhydrite± carbonate (SAC) alteration. The most intense Ca-K-si/icate alteration, a magmatic-hydrothermal breccia, and an early syenite intrusion are all coincident with copper mineralization in the core region of the Central zone. However, higher grade mineralization in the zone, exceeding 1 % Cu with more than 0.5 g/ t Au, is typically associated with intense biotite-rich, K-silicate alteration primarily hosted by altered volcanic rocks. The highest gold grades, commonly exceeding 1 g/t, are associated with bornite-rich mineralization situated in the northern and southern parts of the Central zone.Mineralization in the Southwest zone occurs as disseminated chalcopyrite within a late, diatreme breccia and adjacent K-feldspar porphyry. In the other satellite deposits, disseminated chalcopyrite and bornite occur in volcanic rocks with alteration that is similar to the Central zone."

Jan 1, 1995

By D. Wolfe, R. Cleminson

"The Aurora North mine has been operating for more than ten years, and is the source of over half of Syncrude’s bitumen production. The slurry systems at Aurora experience high rates of wear, and mission lengths on current slurry pumps are nominally 1500-2000 hours. Recent work has enabled a better understanding of the significant adverse effect of large particle impingement damage to impeller vane leading edges - which is the known life determining issue for Aurora hydrotransport pumps. A new pump design has been developed with a larger diameter impeller and increased vane lengths, and is expected to triple Aurora’s mission length for hydrotransport pumps.INTRODUCTIONSlurry Pumps are Critical Equipment at SyncrudeSlurry pumps are a critical component in Syncrude’s operations. In a typical Aurora application, each pump stage helps move over 8000 dry tonnes per hour of oil sand, plus an equal volume of process water that has been added to create the slurry. The average impeller life in oil sand hydrotransport service at Aurora has been nominally 1500-2000 hours, or 12-16 million tonnes of oil sand pumped. Generally, the slurry pump application at Aurora has proven very difficult to improve due to the unique combination of high sand abrasivity, 125 mm (5”) large particle top size (lumps), and high flow rate relative to basic pump size; a factor that results in higher than optimal impeller vane speeds for the service conditions.PROJECT BASISSlurry Pumps are the Reliability Bottleneck at AuroraSlurry pumps are currently the shortest-lived components that determine the overall system run length at Aurora, in Hydrotransport, Extraction and Tailings. Vibrating screens and piping had been previous bottlenecks, but their reliability has been improved through upgrades in equipment design and wear materials. Both vibrating screens and piping can now achieve 4000 hour mission lengths."

Jan 1, 2013

By G. B. Harris, C. W. White

Cyanide has been used for the recovery of gold since the mid 1800s, but several jurisdictions have already banned its use, and environmental pressures are increasing to finding an alternative. Gold also forms chloride complexes similar to those of cyanide, but the use of chloride has never achieved widespread acceptance. This paper describes a chloride-based flowsheet, wherein the key unit process is the recovery and recycle of chloride ion. It is shown that the chloride-based flowsheet is competitive economically with the conventional cyanide-based flowsheets, and that it has a number of other advantages, particularly environmentally.

Jan 1, 2011

By G. B. Harris

It has long been appreciated that chloride chemistry has a number of advantages over the more traditional sulphate route for both extracting and separating metals. Modern materials of construction, coupled with the development of a more cost-effective and efficient hydrochloric acid regeneration technology mean that chloride-based processes are now more competitive and attractive. Such processing routes are able to recover more of the contained metal values in a feed, including iron in a benign and/or marketable form, and particularly the so-called rare and rare-earth elements which are increasing in demand in our electronic age. These factors, therefore, add appreciably both to the overall economics of a project, but also offer a much more sustainable approach to our dwindling natural resources. Additionally, chloride-based flowsheets can be much more environmentally-friendly, offering practical alternatives to two of the biggest headaches faced by the industry, namely cyanide usage and the generation of red muds. This paper presents a brief theoretical background, focusing on the latest developments of ferrous iron oxidation and the low-temperature, selective hydrochloric acid regeneration process, which is the key unit operation for any chloride flowsheet, and discusses in general the advantages of the chloride approach. Several recently-developed flowsheets, which have been tested at the miniplant level, are presented for gold, base metals, titaniferous magnetites and lead-silver ores wherein the advantages of considering a chloride approach are highlighted.

Jan 1, 2014

By Dawei Yu, Kinnor Chattopadhyay

In the nickel industry, molten slags produced from a Pierce-Smith converter contain significant amounts of valuable metals in the forms of oxides and physically entrained matte droplets. A slag cleaning step, which takes places in an electrical slag-cleaning furnace, is therefore required to recover the valuable metals as a common practice. Utilization of a waste material from aluminum industry (i.e. spent potlining) as a flux to improve the slag cleaning in terms of both the metal recovery and the operation efficiency was studied by simulation with FactSage program. Results show that the addition of SPL could substantially reduce the slag viscosity due to its fluoride values, thus accelerating the settling of matte droplets. The carbon value in the SPL could also help increase the metal recovery by reducing the valuable metal oxides followed by settling.

Jan 1, 2015

By E. C. Roper

THE Britannia Mining & Smelting Company, Limited, have been operating their property at Britannia Beach, B.C., continuously for nearly forty years and have mined over 33,000,000 tons of ore from orebodies within a belt of highly sheared rocks, five miles long by 2,000 feet wide. The property is in the Coast Range mountains, about twenty miles due north of Vancouver. The mountains rise abruptly from sea level to elevations of 4, 500 feet within a horizontal distance of 7,000 feet. The topography has enabled the orebodies to be developed by adit tunnels. The active mining levels are connected to the adits by incline and vertical service shafts. The main service adits are the 2200, 2700, and 4100 levels (see Figure 1). The mine surface shops, three bunk-houses, and over one hundred dwellings form the townsite camp at the portal of the 2200 level adit. A small camp of one bunk-house and a few dwellings is situated at the 2700 level portal. The beach surface shops and camp, adjacent to the 4100 level adit, service the mill, foundry, and other beach installations as well as the mining from the 4100 level. The ore mined from the various orebodies is delivered to the 4100 main haulage level through a system of rock raises and intermediate tramming levels and is hauled on the 4100 level to the mill.

Jan 1, 1945