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By Liyuan Chai, Qin Liu, Bing Peng, Jia Wang, Qiang Zhang

"Electrolytic Manganese Residue (EMR) was used as the main material to prepare cementing material activator for the utilization of the residue from electrolytic manganese dioxide (EMD) or electrolytic metallic manganese (EMM) production. The effects of chemical activation, thermal activation and mechanical activation on retarding activity and excitation activity of EMR were investigated according to the setting time and activity index of EMR-slag cementing material. The results showed that the EMR exhibited good activating performance after being ball-milled for 18 min and then treated for 1-2 hours at temperature range of 350-450 ?. The optimal properties of cementing material activator were achieved at the weight percent ratio 30 : 3 : 5 of EMR/Ca(OH)2/cement clinker.IntroductionMany hazardous industrial solid wastes such as blast furnace slag, fly ash, steelmaking slag, chromic slag and electrolytic manganese residue [1] are generated n China and their amounts increases every year. The accumulation of the solid wastes during past years is very huge and they could be hardly recycled effectively as a sustainable resource. 2.35 billion tons of industrial solid wastes have been produced up to now [2]. It is estimated that they would exceed 3.3 billion tons by the end of 2015 [3]. On the other hand, the quick development of Chinese infrastructural construction needs more cementing materials. The production of traditional building materials consumes lots of natural resource such as clay and limestone and discharges at least 1 ton CO2 and other pollutants per ton clinker [4]. Therefore, it is necessary to develop new types of cementing materials instead of clinker [5,6]."

Jan 1, 2012

By F. E. du Plessis

"The distinction between data suitable for process control and data subject to aliasing only becomes quantifiable with the availability of rapid real-time measurements. Expecting the dynamics of flotation to vary for different ore types, process flows and equipment types; a study was conducted to compare the dynamics of different flotation processes. The results shed light on the critical sampling intervals required for process control which in turn allows process stabilization and optimization. The technology used for the in-line measurements is based on diffuse reflective spectroscopy and has been introduced into the mineral processing industry over the past ten years. It has been widely implemented in the sulphide flotation industry in South Africa for the real-time measurement of grade.BACKGROUND AND OBJECTIVE A study was conducted by Du Plessis and Keet (2010) to quantify the minimum sample frequency required for grade and/or impurity control. The study was based on chromite data collected at 15 second intervals from the concentrate line of a flash float cell in the Platinum industry. The data captured the natural process variation of the entrained chromite through water recovery due to changes in feed parameters and flotation performance. It was found that the minimum rate of sampling required from the studied flash float concentrate was 2 minutes. This sampling interval time accounted for 90% of the variance in the process data. It was further found that a sampling interval time of longer than 4 minutes produced data with no significant correlation to reality. The dynamics of the flotation process has been misjudged in the past but can be quantified with the availability of real-time grade measurement based on diffuse reflective spectroscopy. The objective of the study was to compare the dynamics of different sulphide flotation processes through the comparison of maximum sampling interval times required to combat aliasing. All data were collected from single stream analyzers that are currently installed at mineral concentrators. The technology used is based on diffuse reflective spectroscopy."

Jan 1, 2012

By Dale Preece, Steven Case, Cassidy McAllister

Simplot Phosphates produces high quality phosphate fertilizer through open pit mining. The operation near Vernal, UT began as a three-pass mining process carried out with drill and blast followed by the combined effort of shovel-truck and dozer material removal. The first two passes removed the overburden and the final pass mined the relatively hard phosphate ore for processing at the mill. Vertical blastholes were employed in all of the mining passes.

Jan 1, 2012

By S. O. Bada

Coal samples taken from the No. 2 Seam and No. 4 Seam in a South African colliery were tested in a rotary triboelectrostatic separator. The two-stage triboelectrostatic separation results using the -177 µm size fraction reduced No. 2 Seam coal containing about 30.4 per cent ash to a clean product of 8.9 per cent and 13.1 per cent ash with combustible recoveries of 9.6 per cent and 30.7 per cent respectively. The same separation approach on No. 4 seam feed coal, which contained 36 per cent ash, produced a clean coal product with 10.8 per cent ash at a combustible recovery of 6.0 per cent. Petrographic tests show a significant improvement in the vitrinite content and a reduction in visible minerals encountered when using the triboelectrostatic separator, with about 53 per cent vitrinite reporting to the clean fraction for No. 2 Seam compared to the feed content of 21 per cent, and a 54 per cent vitrinite in the clean No. 4 Seam from a feed content of 21 per cent. Significant sulphur reductions were also observed after separation in both coal samples, with a better separation in the second-stage coal products.

Jan 1, 2012

The 30th annual American Mining Hall of Fame Awards Banquet and Fundraiser sponsored by the Mining Foundation of the Southwest (MFSW) will be held at the JW Marriott Star Pass Resort, Tucson, AZ on Saturday, Dec. 1, 2012. Each year, one living inductee, two recipients of Medals of Merit and up to five honorees from mining history are chosen by the MFSW for their outstanding contributions to the mining industry. Gregory H. Boyce will be the guest of honor, featured speaker and inductee into the American Mining Hall of Fame. Boyce, chairman and chief executive office of Peabody Energy, is being honored for his leadership in the coal industry.

Jan 1, 2012

By Defeng Zhou, N. Trubaki, Jian Meng, Fanzhi Menga, Xiaojuan Liu, Yanjie Xia

"The microstructure and the electric conductivity of (Ce0.9Nd0.1)1 xMxO2 d (M=Mo, W) solid solutions were investigated. It has been found that their conductivity containing the grain (s gi ), the grain boundary (s gb) and the total conductivity (s t ) at 300°C- 700°C can be ranked as: (Ce 0. 9Nd 0. 1 ) 0.99 W 0.01 02- d (s gi = 0.065 S.cm·1, (s gb = 0.265 S.cm·1, s t = 0.039 S.cm-1) > (Ce0.9Nd0.1)0.99Mo0.01O2- d (s gi = 0.053 S.cm·1, s gb = 0.142 S.cm·1, s t = 0.029 S.cm-1) > Ce0.9Nd0.1 s 2- d (s gi 0.045 S.cm-1, s gb = 0.091 S.cm-1, s t = 0.018 S.cm-1) measured at 700°C. The highest conductivity is obtained in (Ceo.9Ndo.1)0.99W0.01O2 d. These results indicate that (Ceo.9Nd0.1)0.99W0.01O2- d is the most promising electrolyte materials of intermediate-temperature solid oxide fuel cells among (Ce0.9Nd0.1)1-xMxO2- d. IntroductionRare-earth (e.g. La3+, Nd3+, Gd3+ and Sm3l doped ceria-based ceramic materials have been acknowledged to be attractive electrolytes for solid oxide fuel cells operating below 600°C due to their high ionic conductivity [1, 2]. In order to improve ionic conductivity of these electrolytes further, in recent reports [3-6], some aids such as Mo03 [3] etc. in a limited amount can be used which causes extremely high conductivity. For example, Zhou et al. found that with MoO3 doping, the grain boundary conductivity of Nd3+ doped CeO2- d increased notably especially at lower temperatures due to the effect of severely undersized do pants [3]. It is well known that the size of W6+ (rw6+ = 0.60 Å) is close to Mo6+ (rMo6+ = 0.62A) because of lanthanide shrinkage. Thus, rare-earth doped ceria e.g. Nd3+ doped CeO2g with WO3 in a limited amount will be probably good and even better electrolytes. However, much less information is available about these materials. Therefore, in our paper, (Ce0.9Nd0.1)0.99 1-xMxO2- d (M=Mo, W) solid solutions have been prepared and characterized. Much higher conductive electrolytes are found in the series of (Ce0.9Nd0.1)0.99 M0.01O02- d particularly (Ce0.9Nd0.1)0.99W0.01O2- d"

Jan 1, 2012

By P. J. Sylvester, D. H. C. Wilton, R. I. Wheeler, M. A. E. Huminicki, D. Evans-Lamswood

"Systematic characterization of the mineralogy of massive sulfide ore deposits can provide valuable insights into ore genesis and metallurgical processing that would not be apparent otherwise. We describe a method wherein (1) normative mineral abundances are calculated from whole-rock chemical assays using an algorithm, (2) the results are cast in block models, (3) the results are then verified with automated image analysis of a subset of samples prepared as grain mounts by backscattered electron imaging and X-ray mapping on a scanning electron microscope, and (4) those verified results are integrated with textural data determined by optical microscopy.The technique is applied to the magmatic Ni-Cu-Co sulfides of the Ovoid orebody, based on geochemical assays of 3175 whole-rock samples. Three principal ore zones are defined in the Ovoid. Type I ore occurs in the center of the deposit; it is magnetite-rich and pyrrhotite-poor with intermediate contents of pentlandite and chalcopyrite. Type II ore surrounds Type I ore and is pentlanditechalcopyrite- rich with intermediate contents of pyrrhotite and magnetite. Type III ore occurs at the base and along the outer periphery of the northern part of the orebody; it is pyrrhotite-rich and chalcopyrite- poor with an intermediate content of pentlandite, and a low-to-intermediate content of magnetite. La caractérisation systématique de la minéralogie des gîtes de sulfures massifs peut fournir des indications précieuses sur la genèse des minerais et le traitement métallurgique qui ne seraient pas disponibles par d’autres méthodes. Nous décrivons un procédé par lequel (1) un algorithme est utilisé pour calculer l’abondance de minéraux normatifs à partir d’analyses lithogéochimiques, (2) les résultats sont exprimés dans des blocs diagrammes, (3) les résultats sont par la suite validés par analyse d’image automatisée sur un microscope électronique à balayage en électrons rétrodiffusés et par cartographie en rayons X sur des échantillons constitués de grains montés en résine, et (4) les résultats de cette validation sont combinés aux données texturales obtenues par microscopie optique.Cette technique est appliquée aux sulfures magmatiques de Ni-Cu-Co du gisement Ovoïde, en utilisant les analyses géochimiques de 3175 échantillons de roche totale. L’Ovoïde comprend trois types de minerai. Le type I est situé au centre du gisement; il est riche en magnétite et pauvre en pyrrhotite avec des quantités intermédiaires de pentlandite et de chalcopyrite. Le minerai de type II entoure le minerai de type I et est riche en pentlandite et en chalcopyrite avec des quantités intermédiaires de pyrrhotite et de magnétite. Le minerai de type III se trouve à la base ainsi qu’à bordure externe de la partie nord du gisement; il est riche en pyrrhotite et pauvre en chalcopyrite, avec un contenu intermédiaire en pentlandite et une quantité faible à moyenne de magnétite."

Jan 1, 2012

By M. J. Gregory

The Pebble Cu-Au-Mo deposit in southwest Alaska is one of the world's largest porphyry deposits. The western part of the deposit was discovered by Cominco America in 1987, who sold the project to Northern Dynasty Minerals Ltd., in 2001. Northern Dynasty discovered the high-grade eastern part of the deposit in 2004 and went into a 50:50 partnership with Anglo American PLC in 2007, forming the Pebble Limited Partnership (Lang et al., 2008). The Pebble Limited Partnership has continued to delineate the deposit through diamond drilling with the most recent resource estimate released in February 2010 (Pebble Limited Partnership, 2010). The Pebble deposit mineral resources comprise 5.94 billion tonnes of measured and indicated resources grading 0.78% Cu EQ, containing 55 billion pounds of copper, 67 million ounces of gold and 3.3 billion pounds of molybdenum. Also delineated are 4.84 billion tonnes of inferred mineral resources grading 0.53% Cu EQ, containing 25.6 billion pounds of copper, 40.4 million ounces of gold and 2.3 billion pounds of molybdenum (Pebble Limited Partnership, 2010). Resources are calculated using a 0.3% Cu EQ cutoff. GEOLOGY AND MINERALIZATION Deposit Geology The Pebble deposit is located in the Kahiltna terrane, between terminal strands of the north-east-striking Lake Clarke strike-slip fault. This fault represents an accretionary boundary and separates the Kahiltna terrane to the north-west from the Peninsular terrane to the south-east (Lang et al., 2008). The Pebble deposit represents a large magmatic-hydrothermal system centered on a group of 90 million year old porphyritic hornblende granodiorite intrusions. An east-west cross section through the southern part of the deposit (Figure 1A) shows the typical relationships between the various rock units which host sulfide mineralization. Sub-parallel ~96 million year old granodiorite and diorite sills were intruded into siltstones of the Jura-Cretaceous Kahiltna flysch. In the west, these sills were cut by a ~96 million year old alkalic intrusive complex composed of porphyritic monzonites and monzodiorites and related intrusion breccias (Bouley et al, 1995). The mineralized 90 million year old hornblende granodiorite intrusions cut all rock types and comprise four small stocks in the western part of the deposit and a larger pluton in the eastern part of the deposit. Recent deep drilling indicates that these intrusions coalesce at depth. The strongest porphyry-style mineralization is centered on the eastern granodiorite pluton and extends into the surrounding rock units (Figure 1A). The western half of the deposit crops out at surface, whereas the eastern side is un-conformably overlain by a cover sequence of Late Cretaceous to Eocene sedimentary and volcanic strata. The deposit was tilted 20º to the east during the Eocene.

Jan 1, 2012

By S. Z. Pethö

Pillar extraction at shallow depths with small pillars that were not originally intended for secondary extraction can provide a huge benefit to the coal mining industry in those areas where a significant percentage of the remaining coal reserves are locked up in small pillars at shallow depths and where opencast mining methods are simply not as cost-effective and practical to implement. A system considering all of the pertinent geotechnical and mining aspects for the safe and efficient pillar extraction of small pillars at shallow depths at Xstrata Coal South Africa (XCSA) has been further developed and implemented as part of an ongoing improvement process addressing all of the relevant legal and associated risk aspects. This work follows on from the previous pillar extraction work carried out at the ATC, Boschmans, and Spitzkop Collieries. The process involved a number of in-house workshops and sessions arranged with all key personnel from Tavistock Colliery, and also included Professor Nielen van der Merwe of the University of the Witwatersrand, a world renowned authority on pillar extraction, towards reviewing and developing the Modified NEVID pillar extraction system employed previously at Boschmans Colliery. The system is currently being employed at Tavistock Colliery with success and no major accidents, with around 655 000 t of coal having been successfully extracted from the pillar extraction panels.

Jan 1, 2012

By M. Turner-Jones, N. Steenekamp

"The Lonmin Base Metal Refinery treats converter matte from the Lonmin Smelter to produce nickel sulphate crystals, copper cathode as well as a concentrate containing the platinum group (PGM) metals. The original process employed a Sherritt design and utilizes atmospheric and pressure leaches for the dissolution of base metals. This paper describes the original flow sheet and the improvements made to enhance PGM recoveries, product quality and to increase capacity. Changes include the introduction of flash recycle cooling on the autoclave, batch leaches to improve the quality of the PGM concentrate and the implementation of solid-liquid separation with centrifuges. INTRODUCTIONThe Lonmin Base Metal Refinery (BMR) is about 100 km north-west of Johannesburg and treats converter matte from the Lonmin Smelter to produce nickel sulphate crystals, copper cathode and a concentrate containing the PGMs. The plant was commissioned in 1985 based on a Sherritt design to treat 12 tonnes converter matte per day. The original flow sheet consists of a milling circuit, an atmospheric leach and a pressure leach to produce a PGM concentrate which is despatched by helicopter to the Lonmin Platinum refinery in Brakpan, about 40 km east of Johannesburg. The liquor from the atmospheric leach is treated by crystallization to produce a nickel sulphate hexa-hydrate crystal. The leach liquor from the pressure leach is treated by a selenium removal step followed by electro-winning to produce copper cathode. The spent solution from the copper electro-winning is recycled to both the atmospheric and pressure leach steps to provide sulphuric acid for the leaching reactions.Modifications were made to the original circuit to increase the plant capacity, to improve the PGM recoveries and to improve the quality of the PGM concentrate. Capacity increases included all the unit operations, new mill, new first stage, additional autoclaves, additional nickel sulphate crystallizers, new copper electro-winning and new batch leach reactors for upgrading the PGM concentrate. The current circuit is described in this paper and not the detailed history of each plant change."

Jan 1, 2012

By Wen Liangying, Zou Chong, Tan Xiuqin, Bai Chenguang, Zhang Shengfu

"Eight typical metallurgical byproducts containing iron were selected based on the effect of the chemical composition, particle size, additives on the burnout degree of pulverized coal. Effect of three typical byproducts including fine iron ore, BOF dust and BOF sludge on combustion reactivity and combustion efficiency were investigated using TG-DSC method. The results indicated that the three additives have obvious catalytic effects on pulverized coal. By comparison, the relative active sequence of byproducts to the catalytic combustion can be described as follows: BOF dust>BOF sludge>fine iron ore. Moreover, adding BOF dust as component of additives also shows significant catalytic effects on combustion efficiency during rapid heating process.IntroductionChina is the largest producer in the world with an annual output reaching over 6 billion tons. Solid wastes arising from iron and steel making increases the environment pressure in recently years. For instance, annual output of dust during the production of iron and steel making in China reach up to 5 million tons, which is close to 8%~15% of the amount of steel [1]. Another characteristic of these byproducts is they are finer particle which are just harder to deal with. Since some of solid wastes, including dusts, scales, and sludge, usually contain high iron content, sintering plants have traditionally been used to recycle byproducts in integrated steel plants in China. However these byproducts also have noticeable effects on sinter quality, sinter strength and productivity and, therefore, waste recycling is limited depending on the analysis of the waste materials [2]. Another method which is pre-treatment of byproducts in pelletizing process, increases of energy consumption and production cost. In addition, metallurgical byproducts often contain heavy metals and alkalis. For these reasons, recycling rate of the byproducts in China is very low. Therefore, how to recycle the byproducts in iron and steel making process is an important subject."

Jan 1, 2012

By Tassos Grammatikopoulos, Gary Pearse, Massoud Aghamirian, Charlotte Forstner, Stephen Mackie

"SGS Minerals Services (Lakefield, Ontario site) has conducted a number of developmental and pilot programs that examined methods for the beneficiation, extraction and recovery of lithium from a variety of spodumene containing hard rock sources. An overview of the beneficiation programs is presented separately by Aghamirian, Mohns, Grammatikopoulos, Imeson & Pearse (2011). The focus of this discussion will be the hydrometallurgical steps involved in producing a high grade lithium carbonate (Li2CO3) sample from the spodumene concentrate. SGS has applied the standard Li2CO3 hydrometallurgical flow sheet to a number of spodumene concentrates and has determined that all of these samples respond in a similar manner to the process and produce a final product having a Li2CO3 grade of >99.5%. The standard process is sufficiently robust to accommodate the observed variability in the concentrates that have been tested. Advantage of one spodumene deposit over another will thus be gained through process optimization and innovation. Optimization at the beneficiation stage and at the hydrometallurgical stage must be considered. Some aspects of the process optimization of the hydrometallurgical flow sheet will be presented.INTRODUCTION The current activity in the exploration, development, and mining of lithium based minerals is due in large part to the key role that this metal plays in the rechargeable battery industry (U.S. Geological Survey, 2011). Lithium battery technologies are widely applied in a range of portable electronic consumer products. The expanding development and production of hybrid and fully electric vehicles has contributed to the increased interest in finding and developing new lithium sources in order to meet the expected demand from the lithium battery industry. Lithium may be sourced from continental brines (sub-surface salars), hard rock minerals (pegmatite, spodumene), hectorite clay deposits, geothermal brines and oilfield brines. Currently the majority of the lithium products are produced from Li brines. The four major lithium producing countries are Chile, Australia, China, and Argentina (U.S. Geological Survey, 2009; Roskill, 2009). These countries accounted for 97.6% of the total lithium produced in 2010."

Jan 1, 2012

By Jr. Jones

This paper is derived from a document that compiles autogenous and semi-autogenous mill installations worldwide, through the end of 2010. Updates have been solicited from all major mill manufacturers and most have responded. A review of AG/SAG mills sold to date and in the last five years indicates that the AG/SAG mill market is very healthy and the trend is larger diameter mills with high diameter-to-length ratios. Ring motors (gearless) are the preferred drives for large mills even though the power transmitted through a gear drive is expected to near 11,000 kW per pinion in the near future.

Jan 1, 2012

By Gary B. Petersen

The author has developed a seven-step process called the Applied Rock Mechanics (ARM) Protocol that the author has used to solve numerous roof stability problems in mines throughout North America since 1975. It is a practical evaluation process using trained observation, innovative data collection instrumentation, video borehole cameras, analytical processes, and controlled testing methods that have become highly effective in solving ground control problems in every type of underground mine. This paper will describe each of the steps of the protocol and how the rock mechanics engineer applies them to resolve a typical ground control problem.

Jan 1, 2012

This report is the first in a "final" series of publications on the Juneau Mining District (JMD). This volume summarizes the results of Bureau of Mines (Bureau) investigations in the JMD during the period 1984-1988. Volume 2 consists of a detailed description of Bureau investigations of mineral de-posits, prospects, and occurrences. Volume 3 is a report on industrial minerals within the district. This study has identified and examined more than 300 mines, prospects, and occurrences containing gold, silver, copper, zinc, lead, nickel, cobalt, tungsten, molybdenum, chromium, and PGM. More than 20 of these were discovered during this study. An additional 20 prospects not mentioned in the literature were rediscovered during the JMD study.

Jan 1, 2012

By P. J. Morgan, E. Wolmarans

The selection of the main mineralised zone (MMZ) concentrator milling circuit has followed a comprehensive route over the preceding 10 years. Many knowledgeable parties have contributed and assisted in developing the milling circuit according to the best available information. The final selection of the flow sheet was completed after DRA conducted a techno-economic study on four possible comminution circuits ranging from conventional crushing and ball milling to fully autogenous (AG) milling. The results from all the above mentioned work indicated that it is possible to treat the MMZ ore at the desired throughputs to the desired grind sizes in a fully autogenous grinding circuit. The flow sheet was designed to treat the main mineralised zone (MMZ) arising’s from both underground and open cast operations and incorporates a fully autogenous grinding (AG) circuit. Commissioning of the 375ktpm concentrator at Nkomati Nickel began in August 2009 with the first ore reporting to the mill on the 15th of September 2009.

Jan 1, 2012

By Burcu Ertug, Necip Ünlü

"On average, one out of two glass bottles coming on to the market is provided by recycling processes in Europe. Glass recycling has been started by the early of 1970s in Turkey, and the recycling amount has been reached to 70 thousand tons recently, while 4.2 million tons which represents only 25 percent of total glass manufactured, is the amount of glass collected annually for recycling in the world. The glass recycle process basically involves collecting, sorting, then crushing and grinding after which glass cullet is produced as the secondary raw material. Removing of the contaminants from the glass cullet, and then melting are the next steps. In this study, recent developments of 100% recyclable without any deterioration in quality, and never decomposable glass, are discussed detailed in terms of glass production processes.1.IntroductionIn many countries, waste glass constitutes a large proportion of solid wastes, and recycling the glass is a major environmental problem all over the world [1]. Among the diverse types of waste, glass is one of the most valuable recycling materials because it can be revived and recycled completely and hardly decomposes [2]. Between 80% and 85% of the mass output from the worldwide glass industry is either in the form of containers for the food, beverage, and pharmaceutical industries, or flat glass for building construction or for motor vehicle manufacture. Other product segments, whilst only constituting about 15% of the mass output, produce high value technical and consumer products by comparison with container and flat glass [3].In the present study, the recycling of Liquid Crystal Display (LCD), Cathode Ray Tubes (CRT) and Printed Circuit Boards (PCB) were examined. The production of glasses and glass-ceramics from glass cullet, synthesis of different compounds from recycled glass were other subjects of interest. The use of recycled glass for construction industry and using glass as aggregate were emphasized. Finally the recovery of glass fibers were investigated."

Jan 1, 2012

By I. Masters, K. Buban, M. Faris, M. Antonio, M. Collins

"AngloGold Ashanti Brasil, with assistance from Sherritt International Corporation, has recently commissioned a new autoclave for the pressure oxidation of refractory gold feeds at their Corrego do Sítio operation in Brazil. Design of the new plant, including feed acidulation, pressure oxidation, oxidized solids washing and solution neutralization circuits, was based on the results of test work conducted by Sherritt at their pilot plant in Fort Saskatchewan, Alberta. This paper describes the results of the pilot plant study as well as highlights of the design exercise.INTRODUCTIONAngloGold Ashanti Brasil (AGA Brasil) has recently commissioned a refractory gold pressure oxidation plant at the site of the original São Bento operation in Brazil. The design of the São Bento pressure oxidation facility was based on Sherritt technology; Sherritt carried out the original process development test work in the mid-1980s, provided a process design package and detailed specifications for critical pressure oxidation equipment and participated in the training of operators and commissioning of the plant. The São Bento plant was operated between 1986 and 2007, when the original ore body was exhausted (Silva et al., 2004). AGA Brasil purchased the facility from Eldorado Gold in 2008, with the intent of refurbishing the plant to process refractory gold concentrates produced from the nearby Córrego do Sítio mining area.Sherritt International Corporation has a long history in the development and application of commercial pressure oxidation and pressure leaching processes. Sherritt’s development of technology for the pressure oxidation of refractory gold ores and concentrates commenced in the 1980s in collaboration with Homestake for application at the McLaughlin project in California. This was followed by several commercial applications in Canada, Papua New Guinea and Brazil (Berezowsky et al., 1991). More than thirty pilot plant campaigns investigating the pressure oxidation of refractory gold ores or concentrates have been conducted by Sherritt since the 1980s, and projects with Sherritt contributions to the process development studies and/or engineering design account for about half of the commercial plants that have operated to date with this type of process (Collins et al., 2011a; 2011b)."

Jan 1, 2012

By Anita Marks

In 2007 Copper Mountain Mining determined that there were sufficient resources to consider reopening the Similco Mine near Princeton, BC. The mill facility that had been built by Newmont Mining in 1972 was closed in 1996 and all of the process equipment removed. The mill had been built on the west side of the Similkameen River to facilitate mining of the Ingerbelle Deposit. In 1980 construction was completed on a primary crusher and cable belt to deliver ore across the Similkameen River from the Copper Mountain deposit to the Ingerbelle mill. With the decision to restart mining of the Copper Mountain deposit, the decision was made to design and build a 35,000 tpd grinding and flotation mill near the mining operations. This paper discusses the application of historical operating data for the selection of the mills for the new grinding circuit and provides an overview of the grinding circuit design.

Jan 1, 2012

By Shengli Tao, Hongxu Li, Hao Bai, Yu Chen, Daqiang Cang

"China is the world's largest steel producer, in order to give environment load comprehensive analysis of steel and iron industry in china using LCA method, the life cycle inventory was compiled and assessment model based on Gabi software was also established. Environmental impact of two different routes ofBF-BOF and the EAF were analyzed respectively and intercompared. The results show that the modem EAF route is superior to the traditional BFBOF route on almost all the environmental impact indexes, which including acidification potential, eutrification potential, global warming potential, ozone depletion potential, etc. In the whole life cycle ofBF-BOF route in China, the transporting process ranks the biggest contribution part to the overall global warming potential, which can be explained by the fossil fuel burning of transporting vehicles during the long distance from Australia to China as the iron ore used are mainly imported from Australia. Apart from transporting process, Coking, blast furnace and iron mining processes could induce great environmental problems, while for the EAF route, the electricity consumption is considerable, which causing large amount ofC02 emission indirectly. Based on the analysis, several further countermeasures were proposed. Key words: Iron and steel industry, LCA, Gabi software, C02 emissionIntroductionCrude steel of china which reached 101.24 million tons in 1999 ranked the first column in the world since1999, So far has been to keep the world's largest steel output. At the year of2009, China crude steel output of 568 million tons, accounting for 46.6% of the global crude steel production, more than the total sum of crude steel production produced by 20 countries ranked behind. In 2011, China's crude steel production which is expected to be or close to 700 million tons, an increase of 12% than last year, will account for half of the global steel production.The steel industry, however, is intensive resources industry with huge consumptions of energy and water together with mineral resources. Energy consumption of the iron and steel industry has been about 10% of the total energy consumption since 1980. Coal dominants, power next and other energies share least in the energy consumption structure, for example coal accounts for 72.19%, power 23.52% and other total sums less than 5% in the steel energy consumption at year of 2002[2,3]. The consumption of coal discharges much emission of CO2, yet emissions of C02 in China steel industry, secondary only to the power and cement industry, ranked the third, and the coal dominant energy structure and its process have a close relationship. The aim of this research is to target steel production of typical blast furnace-converter (BFBOF) and electric furnace, using GABI software to evaluate and analyze resources and environment influence of LCA, directing at the existing problems in the development of China steel as well as finding the possible way to improve ability of reducing pollution and energy consumption in order to realize the sustainable development of the steel industry [ 4-7]."

Jan 1, 2012