Search Documents

"Line Creek Resources Ltd. produces three million clean tonnes per year of metallurgical and thermal coals for the international market. The mining operation, which is located in the mountains of southeastern British Columbia, produces coal from four pits by conventional truck and shovel methods.The South Pit, which has been in operation since J982, has a benched highwall 490 m in height. Shallow dipping coal seams at the base of the syncline formation will be exposed in the highwall over the next four years of pit life. The first of these seams, which will measure 500 m in final highwall length, was exposed in J994. An auger, powered by a 1250 hp engine capable of cutting 2.2 m diameter holes, was brought on site in J994 and has proven to be a successful means of recovering coal from the J3 m thick seam.This paper covers the background to the selection of an auger mining method to recover highwall reserves together with the geotechnical and methane considerations for this approach.IntroductionLine Creek Resources Ltd., a wholly owned subsidiary of Manalta Coal Ltd., owns and operates the Line Creek mine. The operation which consists of four active pits, a processing plant, and rail loadout is located in the southeastern coal fields of British Columbia. Figure 1 shows the general area.The coal bearing sequence at the mine is preserved on the east and west limbs of a major syncline. Up to twelve mineable coal seams, ranging in thickness from 2 m to 15 m are contained in the formation. Within the pits the seams are stratigraphically consistent and structurally undisturbed, except for small-scale thrust faults that create multiple repeats of the seams."

Jan 1, 1995

By S. Burling

Australia has a number of uranium deposits, but they vary significantly in their mineralogy, grade and textural characteristics. Therefore, information from traditional (or conventional) sources regarding the fundamentals of leaching the uranium and gangue minerals is not always applicable when studying particular ores. Empirical studies on particular ores can be effective in understanding leach systems and can lead to improvements in process design, but there remains a lack of fundamental understanding which is necessary for ongoing process optimisation as ore bodies continue to vary. ANSTO Minerals has undertaken a program of work to address some of the fundamental questions of uranium leaching, including the unexpected impact for some ore types of leaching at high oxidation potential.

Aug 1, 2010

By M. Maeda, H. Sasaki

"Precious metals such as platinum, palladium, and rhodium are commonly used for automotive catalyst converters. To recover these metals with lower environmental load and cost, exposure to zinc vapor was proposed as a pretreatment prior to acid leaching. Alloying with zinc is expected to enhance dissolution of precious metals and reduce the amount of toxic chemical agents required for the leaching. This study examined the effect of the alloying pretreatment using model catalysts. Catalysts were immersed in leaching solutions for a predefined time with or without zinc vapor pretreatment, and the amount of dissolved metals was then evaluated. INTRODUCTIONAutomotive catalysts account for large portions of the world consumption of platinum (Pt), palladium (Pd), and rhodium (Rh) (Butler, J., 2011). Because of their limited production and high prices, recovery of the precious metals from spent catalysts is obviously an important issue. A representative structure of an automotive catalytic converter can be described as a monolithic ceramic support with a honeycomb structure which is coated with porous oxides such as those of aluminum (Al2O3), cerium (CeO2), and zirconium (ZrO2) (Heck & Farrauto, 2001; Matsumoto & Shinjoh, 2007). Small particles of precious metals, originally several nanometers or less, adhere to the oxides.Typical recovery processes for precious metals from scraps are shown in Figure 1 (a)-(c) (Habashi, 1997; Yoo, 1998; Shibata & Okuda, 2002). Precious metals can be recovered by using non-ferrous smelters as Figure 1 (a) shows. Smelted along with metals such as copper (Cu), precious metals and ceramics in the scraps are absorbed into the metal phase and slag phase, respectively. Because the metals separate from Cu as anode slime in successive electro-refining, such a process can recover precious metals as co-products of Cu. However, in order to prevent negative effects on the principal process, a specialized procedure is needed. Figure 1 (b) is a specialized approach in which scraps are melted at elevated temperature with Cu called the Rose process. Here Cu works as a collector metal, and the absorbed precious metals are then concentrated by oxidation of Cu. Such a process can separate precious metals from ceramics constituting catalyst converters. Smelting at high temperature, however, requires extensive equipment as well as a high amount of energy. On the other hand, hydrometallurgical processes may be effective to separate precious metals from ceramics into an aqueous solution, because chemical agents can act on these metals selectively (Figure 1 (c)). Leaching of precious metals, however, requires strong acid and oxidizing agents because of their corrosion resistance; this makes liquid waste disposal and the large environmental load controversial. To solve the problem, a metal vapor pretreatment was proposed (Okabe, Yamamoto, Kayanuma, & Maeda, 2003a, 2003b; Kayanuma, Okabe, Mitsuda, & Maeda., 2004; Kayanuma, Okabe, & Maeda, 2004; Itoh, Kayanuma, Miyake, Kimura, & Maeda, 2005). A flow diagram of the process using zinc (Zn) vapor is shown by Fig. 1(d). Exposed to Zn vapor, precious metals are expected to form alloys which dissolve more easily than pure precious metals, thus reducing the use of chemical agents and environmental load involved with successive leaching. In previous research (Sasaki, Miyaki, & Maeda, 2010; Sasaki & Maeda, 2010, 2012), dissolutions of precious metal alloys formed by Zn vapor treatment were examined in hydrochloric acid (HCl) using an electrochemical method, and it was confirmed that these metals dissolved at higher rates from the alloys than from their pure states (Figure 2). In this study, the availability of the alloying pretreatment was demonstrated by testing on model catalysts in leaching solutions."

Jan 1, 2012

By Donald J. Farrish

"Mr. Chairman and fellow CMP members, most of these remarks will be made with particular reference to copper concentrate but the basics apply generally to other metal concentrates as well.For very good reasons, using copper as an example, smelting capacity usually is located either close to mine production or close to areas of high copper consumption. The mine producer can add on smelting capacity to insure that the copper in his concentrate can be processed into a marketable form under more or less controlled conditions including costs. On the other hand, the consumer wishing to assure a better supply of copper likewise can build smelting capacity and offer treatment charges attractive enough to discourage mines from investing in their own facilities. In this regard, freight is an important factor. Bulk shipments from the heart of Africa with a large overland component are uneconomic whereas concentrate movements from Australia or South America compare favourably with smaller metal shipments.A mine project which incorporates smelting capacity, will often, through the presence of this capacity, encourage active exploration and development of additional concentrate production in the vicinity. The usual result is that new mines within reasonable distance of the smelter will be able to avoid the capital required to build their own smelting and refining facilities and that the existing facilities will expand to appreciate economies of scale."

Jan 1, 1978

By Serge Ouellet

Identification and quantification of cementitious phases in cemented paste backfill (CPB) is difficult due to the fineness of tailings and the low binder content used in the mixture. Techniques such as X-ray diffraction and thermogravimetry were ineffective (mainly due to tailing mineral interference) to identify and quantify hydration products in most works reported in the literature. On the other hand, scanning electron microscopy (SEM) was used in many cases but mainly for qualitative purposes. This paper presents the development of a new approach based on a computer program (SEM-XMAP) that combines X-ray dot mapping images acquired by SEM and generates a coloured image representing the mineralogy and the microstructure of a given CPB specimen. The technique is applied to one CPB sample mixed with blast furnace slag (BFS) and acidic sulphated mixing water sampled in a mine dewatering system. The technique allowed identifying calcic matrix, unhydrated and partially hydrated BFS particles, and sulphated phases.

May 1, 2007

By M. Kosugi, Y. Kon, M. Kawata, J. V. Satur, K. Mitsuhashi, C. Tokoro, K. Horiuchi, R. Kawarabuki, B. Calabia

"Liberation of copper minerals is important in ensuring high flotation efficiency in copper sulfide flotation. The high pressure grinding roll (HPGR), microwave (MW), and electric disintegration (ED) are known to feature enhanced liberation over conventional comminution machines such as jaw crushers and ball mills by producing internal stresses on minerals or mineral grain boundaries through high compressive forces, thermal expansion of minerals, and pulsed high voltage discharges, respectively. In this study, each of these methods was applied before ball mill grinding to investigate its effect on enhancing the liberation of copper minerals in a low grade and fine-grained copper ore. The copper minerals observed in the tested ore sample are bornite, chalcocite, and chalcopyrite, and their grain sizes range from 10 to over 100 µm. Calcite, quartz, and feldsparare confirmed as gangue minerals. The liberation of the copper minerals by the different methods was analyzed using the mineral liberation analyzer (MLA) and compared. The result showed that the HPGR crushing was the most effective for enhancing copper mineral liberation. HPGR bench-scale test was then conducted on the copper ore and flotation was applied on a HPGR-treated sample to confirm the improvement in the flotation performance by applying HPGR.INTRODUCTIONIn order to recover copper minerals by flotation, copper ore is usually ground by ball milling to liberate the copper minerals from gangue minerals. In the case that the fine size copper minerals are targeted, grinding of the copper ore to a finer size is necessary to increase the copper recovery. However, finer size grinding by ball mill increases energy consumption significantly, which might deteriorate the economies of the mineral processing operation. HPGR, MW, and ED have been recently the focus of researchers as new techniques for enhancing the mineral liberation in mineral processing (Tavares, 2004; Kingman, 1998; Wang, 2010).HPGR crushing is considered to generate micro cracks along mineral boundary when rocks pass between two rolls by applying high compressive force. In the MW treatment, micro cracks are reported to be generated at crystal boundaries by differential thermal expansion of crystals attached to each other. In the ED treatment, micro cracks are known to be produced by plasma current flowing along mineral grain boundaries. These treatments are expected to increase mineral liberation (Fujita, 2001),improve flotation performance(Michaelis, 2005), and reduce ball mill work index(Kaya, 2010)."

Jan 1, 2017

Arguably the SMC Test® has become the most popular laboratory hardness test in the world with over 17,000 tests having been completed to date, covering over 650 different ore bodies. It is now routinely used in design, optimisation and orebody profiling projects. The test is unique in that from relatively small amounts of drill core it simultaneously provides parameters that are used in simulation modelling of AG/SAG and crushing circuits as well as work indices that are used in power-based equations for predicting the specific energies of AG/SAG/Crushing and HPGR circuits. The very large data base that has been accumulated has provided the opportunity to study the differences in variability from deposit to deposit. This paper describes and discusses the trends that have become apparent from the study of this data base. Recommendations for appropriate selection of sample numbers are also made which are based on these trends.

Jan 1, 2012

By Ö Yilmaz

In this study, the behaviour of rock mass subjected to blasting load is investigated using three dimensional finite difference numerical modelling. In the analyses, Mohr-Coulomb failure criterion has been used for the characterisation of the rock mass strength. Stresses acting on the borehole boundary have been simulated by an exponential function which reaches its maximum within a short time and then falls to zero value in a considerable time period. The strain rate effect on the mechanical properties of rock material has also been taken into account in the analyses. Four different explosive-rock mass combinations have been studied to investigate blast induced damage zone. It has been observed that proposed equation for the dynamic compressive strength of rock material fits very well to general suggestions. Results have shown that blast damage analysis model recommended with this study is successful.

Aug 1, 2013

By Qing-Xun Low

Ni current collector has excellent electronic conductivity and mechanica, properties. However, nicke, cannot be used in H2S-containing syngas SOFCs due to sulfur poisoning and coking. Copper coated nicke, is prepared by electrochemica, deposition. XRD, SEM, and EDX techniques are used to characterize the samples. After high temperature treatment in syngas containing, the coated samples exhibit high resistance of coke formation and sulfur corrosion compared to pure nickel. Therefore, copper coated nicke, is a promising anode current collector for H2S-containing syngas SOFCs.

Jan 1, 2010

By F. Rosenblum, P. Spira

A laboratory test has been developed for assessing the patential hazard from self-heating of sulphides. The technique consists in measuring the rate of self-heating, from near ambient temperature, of a 1-kg sample in an insulated chamber controlled at standard atmospheric conditions. The rate of oxygen consumption is monitored simultaneously. The paper describes the apparatus and test procedure, and reports data on various ores and mill products. Tailings known to have caused problems underground when used as backfill have shown heating rates of over 3°C/h. A preliminary hazard rating guide for backfill based on the known behaviour of several sulphide materials is presented.

Jan 1, 1981

By M. P. Amsden

"Ecstall Mining Limited, a subsidiary of Texas Gulf Incorporated operates the Kidd Creek Mine, a 10,000 tons per day base metal producer, near Timmins, Ontario. Two different ore types are mined and milled: copper-zinc and silver-lead-zinc. At the highly automated Ecstall Concentrator the ores are processed by selective flotation in threes individual circuits. One of the most important metallurgical tools for process control is a sample system incorporating continuous on-stream x-ray analysis. Recently this system was further automated by adding computer control of reagents for two copper-zinc flotation circuits. The computer programs, utilizing optimum seeking methods and smelter contract terms, have increased copper recovery 0.8%, zinc recovery 1.6%, and reduced reagent costs by 12%. Although not anticipated, copper and zinc concentrate grades were improved modestly as well.INTRODUCTIONSEcstall Mining Limited, a wholly owned subsidiary of the Texas Gulf Incorporated operates the Kidd Creek Mine, one of the world's major base metal producers, near the old gold mining centre of Timmins, Ontario. Discovered in 1964, the property was brought into production in November, 1966. Originally designed for 9,000 tons per day, the operation now treats 10,000 tons per day of two different ore types mined from a single open pit. In the near future, open pit ore will be supplemented by ore from an underground operation now being readied for productionAt the Ecstall Concentrator the ores are processed by selective flotation in three individual circuits. The whole plant is highly automated and control is coordinated from a central control room. The treatment process follows conventional practices although fine grinding is required for optimum flotation recoveries. Normally, two circuits treat copper-zinc ore at a combined rate of 6,500 tons per day while the third circuit treats 3,500 tons per day of silver-lead-zinc ore. Special production averages 2,400 tons per day."

Jan 1, 1973

By Y. -B. Kang

New databases are being developed to provide the capability to evaluate the suitability of present and potential new Mg alloys for automotive applications through cost-effective calculations. An extensive and complete thermodynamic database is being prepared for Mg alloys formed from among 25 present and potential alloying elements. The database is being developed by critical evaluation, modeling and optimization of available phase equilibrium and thermodynamic data. It contains model parameters giving the thermodynamic properties as functions of temperature and composition. Using the FactSage thermodynamic software, users can access the database to calculate the amounts and compositions of all phases at equilibrium at any temperature and composition or to calculate any phase diagram section in multicomponent alloys, to follow the course of equilibrium or non-equilibrium cooling, to calculate corresponding heat effects, etc. A database of densities and lattice parameters of Mg alloys and intermetallics (as functions of temperature and composition) is also being developed in order to permit the calculation of volume changes during cooling and phase transformations, c/a ratios of the hcp phase, etc.

Jan 1, 2006

By Y. Chino

Cross-rolling, in which the roll axis is tilted by 7.5 degrees against the transverse direction, was carried out on a commercial magnesium alloy. The (0002) texture intensity of the cross-rolled specimen was lower than that of the unidirectionally rolled specimen. Also, the grain size of the cross-rolled specimen was smaller than that of the unidirectionally rolled specimen. As a result of the Erichsen tests at 433 ? 493 K, the press formability of the cross-rolled specimen was higher than that of the unidirectionally rolled specimen. The high formability of the cross-rolled specimen is attributed to both the reduction in (0002) texture intensity and the enhancement of grain refinement by the cross-rolling.

Jan 1, 2006

By Ron Tessier, Claude Bazin, Robert Grant, Mike Cooper

"Grinding simulators are now widely available to assist in the optimization of industrial circuits. They provide circuit operating conditions or flowsheet designs that yield a given product size distribution. However, they do not provide information of the impact of a change of product size distribution on the subsequent flotation or leaching stages. This paper presents a method to predict grade and recovery indices for a flotation plant as a function of the flotation feed size distribution. The application of the method to various size distributions allows the determination of the optimal fineness of grind. A case study for a CuPb rougher circuit of a New Brunswick complex sulphide processing plant is presented to illustrate the method.IntroductionIs the grinding circuit product fineness optimum for the subsequent separation steps? This is a question that is certainly very difficult, but critical, to answer. Laboratory and pilot plant testworks can provide clues as to whether grind should be finer or coarser. For a full scale operation there is no other way than trying to change the setup of the grinding circuit and verify the effect on flotation. True effects can, however, be masked by the numerous and unexpected disturbances inherent to grinding and flotation circuit operations. A good preliminary investigation requires a noise free environment to elaborate possible solutions for the question.Plant simulators provide this noise free environment. However, despite grinding and flotation simulators having evolved significantly for the last 20 years, very little is available on the integration of both simulators to analyze the effect of fineness of grind on metallurgical performances. For instance, a grinding circuit simulator may help to find the tuning of a grinding circuit that will yield the desired fineness of grind, but does not inform on the effect the new product size distribution will have on the separation stages. Linking grinding and flotation would require a flotation plant simulator with the rate and infinite recovery parameters for each mineral in each size interval considered. This approach is seldom used because of the tedious work required to estimate the model parameters. Recently Leroux(1992) proposed a method to predict mineral liberation from grinding ore of known mineralogical texture. Although the method is still at its infancy it may provide, when combined with a reagent conditioning model (e.g Niemi et al., 1982; Bazin et al., 1988), a way to simulate flotation without the need of entering the numerous parameters of a flotation model."

Jan 1, 1994

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

Inco Limited has been evaluating options for streamlining the overall flowsheet at its Sudbury, Ontario operations to improve productivity and to minimize the cost of at¬mospheric emissions reduction. Some of the flowsheets being considered include vari¬ous levels of copper/nickel separation at the Clarabelle Mill where all Inco's Sudbury Basin ores are processed. This paper reports on the laboratory and miniplant studies car¬ried out during the flowsheet development for a commercial Cu/Ni separation plant. There are two potential feed streams for Cu/Ni separation. It was determined that Cu/Ni separation from the rougher concentrate requires no regrind, and a very clean copper concentrate is produced, but the recovery of copper is limited to about 70% from ore. Cu/Ni separation is more difficult from the bulk concentrate because of the presence of excess flotation reagents in the slurry and due to locked particles. By replacing the slurry water with clean process water, and by addition of some hydrogen peroxide, entrainment is minimized and excess reagents are removed from the surface, providing a satisfactory separation of copper from nickel. Fine regrinding is required to increase liberation of the locked particles and to obtain 85% copper recovery with minimal nickel contamination of the concentrate.

Jan 1, 2005

By T. R. Madhavan

The development of contact angles on highly polished ?uraninite surfaces, using sodium oleate and dodecyl ammonium acetate as collectors, has been studied at different collector and hydrogen ion concentrations. It was found that sodium oleate in acidic media (up to a neutral: PH) and dodecyl ammonium acetate in neutral and alkaline media give good contact angles. It appears that the combined forms of these collectors, viz., oleic acid and free amine, are more important in effecting contact. W ITH the emergence of uranium as a strategic metal in the last fifteen years, considerable effort has been directed toward the commercial recovery of uranium from its ores. This has resulted in the development of a uranium technology. It is only in recent years, However, that fundamental data regarding the floatability and surface properties of uraninite and ?pitchblende have been elucidated by different methods. Contact-angle measurement is one of the important tools for tl1e evaluation of the conditions of floatability

Jan 1, 1964

By J. L. Barton, R. A. Murray

"This paper looks at how Syncrude Canada Ltd. is utilizing the Conveyor Belt Monitoring technology developed and patented by the Australian CSIRO and licensed to Syncrude by Conveyor Belt Monitoring of North America, Inc. The technology involves magnetizing the steel cables in the conveyor belts and detecting the fields produced by breaks, gaps or cable ends using special sensors which feed the signals into a multi- channel recorder to provide permanent traces of the various events taking place in the steel cable belts.The data is analyzed and combined with existing belt audit programs, to assist in predicting belt life, change-out criteria and belt design, belt loading and construction. All of these applications of the CBM technology leads to better utilization of resources and forms an integral part of the conveying system reliability program."

Jan 1, 1992

By L. Mercier, A. El-Hsaeri, L. Amaratunga

Laboratory scale studies of the development and application of high capacity heavy metal ion adsorbents with uniform nanoscale porosity (denoted MP-HMS, mercaptopropyl - hexagonal mesoporous structure) to extract gold from solutions is described. The adsorbents are selective towards gold ions. The adsorption capacities of these materials are also among the highest reported. MP-HMS has shown the capability to adsorb 330-mg gold per gram adsorbent (up to 30% of their weight). Gold uptake by the adsorbent was found to increase dramatically with solution agitation. The adsorbent was found to be extremely effective in adsorbing gold ions from ultra- low concentrations, like those found in mine effluents. Experimental studies indicated that MP-HMS maximum adsorption of gold (99.9%) occurred under all solution concentrations. Another promising attribute of these materials is their favorable adsorption kinetics. The contact time required for 80% adsorption of gold was found to be less than 60 seconds. The efficiency of these nanoporous materials for the recovery of gold from mining effluent is evaluated and their prospect for application in the mining industry discussed. The process thus has the prospect of becoming an efficient and environmental friendly method to recover gold from aqueous solutions, such as gold mill effluents.

Jan 1, 2004

By R. Tomás, J. B. Serón, M. Romana

The Slope Mass Rating (SMR; Romana, 1985) geomechanics classification was developed as a sequel of Bieniawski’s Rock Mass Rating (RMR) system, which was almost impossible to use in slopes due to the extreme range of the correction factors (up to 60 points of a maximum of 100) and to the lack of definition of them. A detailed quantitative definition of the correction factors is one of the advantages of SMR classification. During the last thirty years the use of SMR system has been extended to many countries from the five continents and, thus, it is time to review the most interesting developments. Both RMR and SMR are discrete classifications, depending on the values adopted by the variables that control the parameters. This can cause major changes in the parameters value due to small differences in the variables value, with changes in the final rock mass assigned quality. On the other hand, geomechanics quality indexes are extremely biased. To avoid this problem, some authors have proposed continuous functions for SMR. This classification has been also adapted for its application in heterogeneous and anisotropic rock masses, for high slopes, for is application trough stereographic projection and Geographical Information Systems, has been used as susceptibility rockfall parameters and has been included in the technical regulations of several countries. Additionally, some open access computer tools have been developed for the computation of SMR. Consequently, this paper reviews: 1) the most important modifications and adaptations of slope classifications which derive directly from SMR; 2) the use of SMR throughout the world; 3) many significant papers on slopes analysed with SMR all over the world; and 4) future trends in the use of SMR.

Jan 1, 2015