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By Y. M. Shneerson, I. V. Fomenko, M. A. Pleshkov, E. A. Ospanov, A. A. Shakhalov, S. S. Naboychenko

Low-grade copper concentrates (with copper content less than 20%) often contain impurities such as arsenic, zinc, lead, mercury, antimony and bismuth. The pyrometallurgical treatment of such concentrates is associated with several problems, which will ultimately affect the cost and the quality of copper cathodes as well as by-products. SRC Hydrometallurgy proposed a complex hydrometallurgical technology which allows the removal of impurities and the enrichment of low-grade copper concentrates to a quality which will be more suitable for pyrometallurgical processing. Laboratory batch tests and pilot plant results for the pressure leaching steps are shown in this paper. The key parameters of the leaching steps were determined and optimized. The quality of possible by-products were also determined. The developed flowsheet includes two pressure leaching steps: pressure oxidation (POX) and hydrothermal alteration (HTA). Both operations are carried out at 170°C with subsequent flotation of POX and HTA residues and recovery of copper, zinc and lead into separate concentrates for further processing. The development of the flowsheet was based on the Balkhash Zinc Plant (Balkhash, Kazakhstan), which had been non-operational since 2009. The developed flowsheet for processing of low-grade concentrates will utilize 80% of the existing equipment of the Balkhash Zinc Plant, thus leading to a significant reduction in required capital expenditure. INTRODUCTION As the age of copper mining operations advance, copper grades continue to diminish and impurity levels increase. Therefore, copper producers are forced to look for new innovative hydrometallurgical technologies which are able to handle low-grade raw materials and solve problems associated with impurities in an economically justifiable way. New technologies allow to extract valuable components selectively and to process low-grade concentrates which had previously been marked as non-technological and economically unviable. Hydrometallurgical technologies for processing of copper-containing materials can be divided into two main categories: chloride and sulfate (atmospheric, autoclave and bacterial) based technologies. Since the 1970s, many autoclave techniques for the processing of copper-containing materials have been developed and implemented (Naboichenko, 2002; Dreisinger, 2005; Habashi, 2009; Shneerson, 2011). The mineralogical composition of the ore (or concentrates), geographical location of the deposit, distance from industrial areas, availability of existing treatment facilities, availability of skilled labor, cost of electricity and cost of neutralization are some of the factors which are usually considered when the appropriate technology is selected (Halbe, 2002).

Jan 1, 2019

By D. G. Macintyre

Thick westward prograding clastic wedges were deposited along the margin of ancestral North America from Mid-Proterozoic to Mid-Paleozoic time. Periodic rifting and tectonic subsidence resulted in the formation of starved sub-basins along this otherwise passive continental margin. These sub-basins host important sedimentary exhalative barite-zinc-lead-silver deposits. In northeastern British Columbia, a thick succession of Paleozoic basinal facies clastic rocks is preserved within the northwest-trending Kechika Trough. Within the trough, sedimentary exhalative barite and barite-sulfide deposits occur in starved basin sediments of Middle Ordovician, Early Silurian, and Late Devonian age. The last are the most economically sigrrificant and are hosted by carbonaceous cherty argillites and siliceous shales of the Middle to Late Devonian Gunsteel Formation of the Lower Earn Group. The largest deposit, Cirque, has reserves in excess of 35 million tonnes averaging 100J0 (Pb +Zn) and 47 g/t Ag. Other potentially significant deposits include Driftpile Creek, Bear, Mt. Alcock, Fluke, Pie and Elf. Stratiform barite deposits are also common, particularly near the basin-to-shelf transition zone. The Late Devonian barite-sulfide deposits typically are zoned: interlarninated barite-sphalerite-galena-pyrite occurring near suspected vent areas grades outward into bedded barite. Laminated beds of pyrite typically occur in hangingwall siliceous shales, particularly above the inferred vent zone. The apparent absence of epigenetic stringer sulfide zones and footwall alteration implies that the deposits were formed from ponded brines at relatively low temperature. Away from the main deposits, the favourable stratigraphic interval is marked by the presence of thin beds of nodular and laminated barite and thin laminae of pyrite. Thin tuff beds also occur locally in this stratigraphic interval and are evidence for a Late Devonian volcanic event. A paleogeographic reconstruction of the Kechika Trough in Late Devonian to Mississippian time suggests that the barite-sulfide deposits formed in third-order starved basins between uplifted, northwest-trending horst blocks that were capped by shallow-water carbonate banks. The presence of intraformational breccias suggests that fault movement accompanied barite-sulfide precipitation. This tectonic activity may have allowed the escape of heated, overpressured metalliferous brines from permeable reservoirs within the sedimentary pile. Sedimentary exhalative deposits formed where these brines were exhaled as buoyant plumes onto the seafloor, cooled, and ponded in anoxic seafloor depressions.

Jan 1, 1992

By Gene O. Cowie

"Zinc, which once enjoyed an unchallenged position in the field of decorative applications, has lost a substantial share of its markets to other materials, particularly plastics. This turn of events has led the zinc industry to explore new market areas, particularly those applications where the engineering properties of zinc can be utilized. This paper gives an overview of the zinc industry's efforts to develop the data base and product development technology which have enabled zinc alloys to emerge as engineering materials. It also indicates those areas in which the research facilities of the zinc industry must be employed to ensure that zinc alloys keep pace with developments in competitive materials and processes.The Materials RevolutionThe development and utilization of new materials and manufacturing processes progressed for centuries by evolution. Recently it erupted into a revolution, which may become as significant as the industrial revolution. The materials revolution has impacted upon many industries, but none has been affected more traumatically than the North American automotive industry. The plight of that industry is of great importance to us because their problems have, to a great degree, become problems to the zinc industry.Much of the impetus behind the automotive trauma came from the battery of motor vehicle regulations promulgated by the United States government in the 1970s. These regulations required that the efficiency of passenger cars, in terms of miles per gallon, be approximately doubled in ten years. In view of the fact that major changes in the automotive world require three years of lead time to implement, the industry was left with only seven years to perform the task. The automotive industry was simultaneously required to make progress in other areas, such as reduced emissions, reduced cost of repairs and increased levels of occupant safety. These added demands not only diverted some of the available resources away from efficiency goals, they often ran in direct conflict. For example, when you are required to provide a front bumper which will absorb the energy of a 5-mile -per-hour barrier collision, you must add both hardware and structure to the vehicle. This adds weight, and increased weight reduces miles per gallon."

Jan 1, 1983

By A. Hosseini

Full-scale rupture tests were conducted on 508 mm (20 in) diameter API X-60 5.7 mm wall thickness pipes containing either axial semi-elliptical cracks or simulated corrosion defects with equivalent depths ranging from 20 to 60 percent thickness. In the case of the cracks, the failure pressures were predicted with reasonable accuracy when considering a level 3 failure assessment diagram (FAD) procedure based on API 579, as compared to level 2 FAD, since the mechanical properties were known. In both cases, the accuracy improved for shallower cracks. Considering simulated corrosion defects, the RSTRENG approach provided more reliable results on predicting the collapse pressure. For a similar depth and profile, the cracked pipes failed at a lower pressure than those containing simulated corrosion defects of equivalent depth.

Jan 1, 2010

By David G. Dixon, Ahmad Ghahremaninezhad, Edouard Asselin

"Atmospheric leaching of chalcopyrite in sulfuric acid solutions is a slow process due to the mineral’s passivation. We have investigated the nature of the passive film in this work. Electrochemical reduction and oxidation of chalcopyrite over the potential range of -0.5 to 1.2 VSHE were investigated in 0.5 M sulfuric acid solution (pH 0.3) at 25 ºC by multicyclic voltammetry and open circuit potential measurement. The influence of scan limits on the evolution of current peaks was studied with both stationary and rotating electrodes. It was observed that the anodic oxidation of chalcopyrite begins at potentials above 0.6 VSHE, most likely by preferential dissolution of iron atoms over copper atoms. The selective electro-dissolution process results in formation of a metal-deficient sulfide passive film (i.e. Cu1- xFe1-yS2, y > x). The passive film dissolves at 0.9 VSHE. Elemental sulfur is one of the products of chalcopyrite dissolution above 1.0 VSHE. Cathodic reactions within the potential region of 0.1 to 0.6 VSHE and anodic reactions at potentials lower that 0.5 VSHE are associated with at least one soluble species from solution. The soluble species involved in the cathodic reactions are likely ferric and cupric, while the soluble species involved in the anodic reactions is likely H2Saq."

Jan 1, 2014

By M. Tanaka, H. Narita, T. Fuchikami, K. Morisaku, K. Nagao, T. Yoshida, K. Kuroda

The effect of various N-substituents on the performance of amide-containing tertiary amine compounds in the extraction of Rh(III) from HCl solutions was investigated to optimize the structure of these compounds for industrial use. It was found that N-2-ethylhexyl-bis(N-di-2-ethylhexyl-ethylamide)amine and tris(N-di-2-ethylhexyl-ethylamide)amine, which have long, branched alkyl chains, were suitable for Rh extraction, because they were soluble in a practical diluent (80 vol% n-dodecane?20 vol% 2-ethylhexanol) and stable against highly concentrated HCl/Rh solutions, and showed high selectivity for Rh(III) over Pd(II) and Pt(IV).

Jan 1, 2014

By Ruan Chi, Zhenyue Zhang, Zhengyan He

In order to understand what governs the leaching of exchangeable rare earth (RE) and impurities and enhance the RE leaching process, the effects of the concentration of ammonium sulfate, pH and leaching temperature on the migration of RE and aluminum (Al) during the leaching of weathered crust elution-deposited rare earth ore was studied. The elution curves for ammonium ion (NH4 +) were also studied to reduce the consumption of the leaching agent. It was found that a high concentration of leaching agent can enhance the leaching process of RE and Al, reduce the breakthrough volume of NH4 + and more rapidly obtain the equilibrium of NH4 +. However, excessive leaching agent can both increase the cost and the burden on the environment. There is almost no variation on the elution curves of RE and Al in the pH range of 4-8 and control of the pH of the leaching agent can be omitted. It is better for the leaching work to be done in summer since higher temperatures can enhance the RE leaching process and improve the use ratio of ammonium. Using 0.1 mol/L ammonium sulfate for leaching 250 g RE ore, 95.42% RE extraction can be obtained when the volume of leachate is 102.6 mL. At this moment, only 18.17% of NH4 + is used to exchange RE and 49.22% of NH4 + is left in the leachate that can be reused as leaching agent by replenishing ammonium sulfate. The results of our studies can provide theoretical guidance for high efficiency and low consumption exploitation of RE ores.

Jan 1, 2016

"NI 43-101 is a rule that governs how issuers disclose scientific and technical information about mineral projects to the public in Canada. The disclosure standards apply to oral statements as well as written documents and websites. NI 43-101 does not apply to disclosure concerning petroleum, natural gas, bituminous sands or shales, groundwater, or coal be methane. NI 43-101 first came into force on Feb. 1, 2001 and was revised in December 30, 2005. As a “National Instrument”, the law has been passed in each provincial and territorial legislature across Canada.“PART 1 DEFINITIONS AND INTERPRETATION 1.1 Definitions - In this Instrument “adjacent property” means a property(a) in which the issuer does not have an interest;(b) that has a boundary reasonablyproximate to the propertybeing reported on; and (c) that has geological characteristics similar to those of the property being reported on; “data verification” means the process of confirming that data has been generated withproper procedures, has been accurately transcribed from the original source and is suitable to be used; “development property” means a property that is being prepared for mineral production and for which economic viability has been demonstrated by a feasibility study; “disclosure” means any oralstatement orwritten disclosure made by oron behalf of an issuer and intended to be, orreasonablylikely to be, made available to the public in a jurisdiction of Canada, whether or not filed under securitieslegislation, but does not include written disclosure that is made available to the public only by reason of having been filed with a government or agencyof government pursuant to a requirement of lawother than securities legislation; “early stage exploration property” means a property that has(a) no current mineral resources or mineral reserves defined; and (b) no drilling or trenching proposed; in a technical report being filed in a local jurisdiction; “exploration information” means geological, geophysical, geochemical, sampling, drilling, trenching, analytical testing,assaying, mineralogical, metallurgical and other similar information concerning a particular property that is derived fromactivities undertaken to locate, investigate, define or delineate a mineral prospect or mineral deposit; “feasibility study” means a comprehensive studyof a mineral deposit in which all geological, engineering, legal,operating, economic, social, environmental and other relevant factors are considered in sufficient detail that it could reasonably serve as the basis for a final decision by a financial institution to finance the development of the deposit for mineral production; “historical estimate” means an estimate of mineral resources or mineral reserves prepared prior to February 1, 2001;“IMMM Reporting Code” means the classification system and definitions of mineral resources and mineral reservesapproved by The Institution of Materials, Minerals, and Mining in the United Kingdom, as amended; “JORC Code”means the Australasian Code for Reporting of Mineral Resources and Ore Reserves prepared by the Joint Ore Reserves Committee of the Australasian Institute of Mining and Metallurgy, Australian Institute ofGeoscientists and Mineral Council of Australia, as amended; “mineral project” means any exploration, development or production activity, including a royalty interest or similarinterest in these activities, in respect of diamonds, natural solid inorganic material, or natural solid fossilized organic material including base and precious metals, coal, and industrial minerals;"

Jan 1, 2003

By J. E. Rowland

NIOCALITE is a new mineral species which has been identified in rock from the Oka district, Quebec. It occurs as prismatic crystals up to l 0 mm. in length and I mm. in width, in coarse, white, crystalline calcite with associated apatite, diopside, biotite, pyrochlore, and niobian perovskite. The crystals of niocalite are light yellow in col-our and have a vitreous lustre. The optical properties of niocalite (I) are as follows: Biaxial negative -2V = 56° a = 1.700, [ ] = 1.730 Birefringence y -a = 0.030 Optic orientation: X = b, Z/\c 12°, Y , /\a = 32° The specific gravity is 3.32 and the hardness is approximately 6 (Mohs scale). A detailed analysis performed on 2.4 gm. of hand-picked material reveals that niocalite is essentially a calcium niobium silicate. Table I gives the result of the analysis. Crystals of niocalite, apparently suitable for X-ray diffraction work, were selected, and single crystal photographs were obtained using both Weissenberg and Precession cameras. Initial difficulties were encountered in interpreting these films, and in correlating the crystal data with the optical data. The in-consistencies were explained by the fact that every grain examined was twinned to some extent.

Jan 1, 1957

By Curtiss O. Ehrsam, M. Naseem Mian

Alaska’s Red Dog Mine is strengthening its position within Cominco’s “Vision 2000”strategic plan by continually improving quality and quantity of production while reducing costs. Red Dog has evolved into a stable and mature operation, after six years of milling experience. A high grade, partially oxidized orebody in the severe Arctic environment, along with competing producers in a volatile metals market, are the continuing challenges facing Red Dog. The Red Dog Mine is striving to meet these challenges with emphasis on operator training combined with creative systems development and increased production. This paper describes developments in operations along with future plans.

Jan 1, 1996

By Per-Lennart Nystedt

"The Boliden Lead Kaldo Plant for the treatment of lead bearing flue-dust from the Copper Smelter and the Slag Fuming Plant has been in operation at the Ronnskar Works of Boliden Metall since the middle of 1976. At the present stage, the plant can treat lead-bearing dust of different kinds and compositions. The process allows good separation of arsenic and halogens from lead.The flue dust from the Copper Smelter and the Slag Fuming Plant is very complex and, apart from lead, also contains zinc, copper, tin, bismuth, cadmium, antimony, arsenic, sulphur, silver, chlorine and fluorine. The metallurgical process has been developed by Boliden Metall and has been tested on a pilot scale at the Foundation for Metallurgical Research (MEFOS) in Lulea, Sweden.The pelletized dust is smelted in the converter, where the heat is generated by an oil oxygen burner. The second step consists of reduction with coke. A lead bullion and slag are obtained. The slag, transported in liquid form, is treated in the Slag Fuming Plant for the recovery of zinc. The third step is the elimination of arsenic from the bullion. This is achieved by treating the lead with iron (turnings or pellets). The result is a crude lead and speiss. The lead contains silver, tin, antimony and bismuth, and is suitable for the final refining stages in normal plant equipment for refined lead.For process control, we use the rapid analysis centre, which is pneumatically and electronically linked to 'all major plant sections and allows for a quick turn-around between delivery of the sample and feedback of results. All three steps in the process are performed in the same converter.Since the starting up of the plant, the original process has been subjected to some modifications. Initial problems related to equipment, maintenance and environment have been solved step by step. Examples are quoted. Recent operating particulars are presented."

Jan 1, 1980

By E. Goodwin

"Maclaren Forest Products Inc.Lime is commonly used for the neutralization of acid, and the removal of heavy metals in mine waste waters. However, the precipitation of heavy metals as hydroxides must take place under conditions of controlled pH, to produce minimum concentrations of dissolved metals. An account is presented explaining the concepts applied to lime-treatment processes at Bell Mine during the period of a supernatant discharge to Babine Lake; October 18, 1982to January 25, 1983. IntroductionBell Mine of Maclaren Forest Products Inc., Babine Mining Division, an open-pit copper mine, is located on Newman Peninsula, Babine Lake approximately 65 kilometres northeast of the town of Smithers, British Columbia (Fig. 1).A depressed market for copper metal in 1982 forced a management decision to suspend operations at the mine for an indefinite period from October 3 I, 1982. For some time prior to the mine closing date, mine management was concerned about the increasing level of supernatant in the tailings pond , and its possible effects on the stability of the dam when cycloning of mill tailings ceased. Consideration of these potential hazards led to an application being filed with the Provincial Waste Management for a permit to discharge the excess water to Babine Lake. This large lake, an important link with several significant salmon spawning sites, is a major contributor to the British Columbia commercial fishing industry. Jurisdiction for the environmental affairs in the area is shared by the Department of Fisheries and Oceans, the Environmental Protection Service, and the Provincial Waste Management Branch. These agencies were directly concerned in the formulation of discharge permit following joint consultation, and exchange of information with the company on environmental concerns. An approval was finally granted to discharge approximately 1,000,000 cubic metres of supernatant from the tailings impoundment at Bell Mine into Hagan Arm, Babine Lake from October 18, 1982 with a daily discharge not to exceed 9000 cubic metres. Provisions were made that a particular discharge procedure be followed, and that the company would be responsible for setting up a sampling and monitoring program to safeguard the quality of the effluent."

Jan 1, 1986

By Min-Yuan Cheng

Landslides not only cause interruption of road traffic but also cause damage to passing by vehicles and injure people in Taiwan. Due to the budget limitation of government, the overall assessments and maintenance of all road slops cannot be fulfilled. Priority of road for maintenance is a crucial task for road maintenance department to identify. The purposes of this research are to develop an assessment method for the landslide risk and to make strategies to maintain or repair the slopes along mountain roads. To aim both needs to take into account the environmental conditions of the slopes, the engineering measures for stabilizing road slopes, the transportation issues, and the human concerns when dealing with the slopes maintenance along the mountain roads. This study firstly establishes the Landslides Damage Risk Evaluation Model (LDREM) to calculate the risk of slope failure, considering the probability of landslides, temporal probability, spatial impact probability, the value of human life, transportation time increased, and travel cost due to detour etc., and then the loss of life and transportation can be calculated. Secondly, based on the value of risk and the risk evaluation, considering the risk acceptance criteria for loss of life could provide assistance for road maintenance department to determine the priority of mountain roads for maintenance.

Aug 1, 2013

By Carricajo T., S. Nazari

This paper discusses a unique dynamic solution for optimizing comminution area in real time. The proposed technology is a combination of model predictive controller, optimization methods and real-time digital twin for mineral processing. For grinding area, the ultimate goal of an effective control strategy is to maximize the mineral processing, reduce energy consumption and stabilized size classification. To have a continuous and effective comminution operation, a reliable control system that minimizes the need for human intervention is necessary. The implemented advanced control strategy for comminution area consists of two layers in hierarchical structure. The lower layer objective is to stabilize the process stabilization using model based predictive controller (MPC) technique. The unique MPC used in this layer is called BrainWave™ chosen for its robustness, convergence and delay handling; furthermore, the developed platform offers stable and repeatable solution and has short implementation time. The upper layer is a supervisory control, which sends the preferred process operation points to the lower layer to drive the process towards optimal performance. The goal of this layer is to optimize the process targets, as well as making decision. To increase process performance, automatic ore characteristic adaptations are implemented in this layer. A digital twin of comminution area is built in the second layer that runs amongst the process in parallel. By communicating, the process data in real time, a virtual densitometer is built that is being used in our advance process control strategy. Our control strategy has been developed, tested and implemented in various areas of a copper concentration plant. The targets for implementing advance process control are usually increased throughput, decrease energy consumption and variability reduction in particle size distribution. Overall, the results showed in different mine sites are increase throughput between 2 and 5%, specific energy consumption reduction about 15% and process variability reduction up to 60%. In this paper we discuss the results of the recent implementation of this technology on Minera Los Pelambres, Minera Collahuasi and CAP Minería. Their concentrator plants have installed control systems with the most updates optimization features, for SAG mill, ball mills and thickeners.

Jan 1, 2019

By D. M. Ward, J. H. Ahrens

"The Fond-du-Lac uranium deposit was delineated primarily by percussion drilling and a small program of diamond drilling. Drillcore samples from three diamond drill holes as well as digitized gamma logs from percussion and diamond drill holes were utilized to define and implement an algorithm for the conversion of gamma-log data to equivalent-grade data. The procedures and detailed analysis for the provision of assay data for uranium reserve estimation are documented.IntroductionThe Fond-du-Lac uranium deposit is on the south shore of Lake Athabasca, approximately 2 km southeast o f Fond-du-Lac , northern Saskatchewan. It is on the northern rim o f the Athabasca sandstone basin.A train of mineralized glacial erratics was discovered in 1967 by Farnok, Limited by means of a helicopter-borne radiometric survey. In 1969, a program of diamond drilling by Famok was successful in locating in-situ mineralization in the Athabasca sandstone at the apex of the mineralized boulder train. Since 1974, exploration and development work have been performed under a joint-venture agreement between Eldorado Nuclear Limited and Famok Limited, with Eldorado acting as operator.From the discovery drill hole to the development of the gamma-log to equivalent-grade con version algorithm, the deposit had been tested by a total of 222 drill holes, 210 of which were percussion holes and 12 of which were diamond drill holes. The holes are generally vertical and collared at 10-metre centres on fences spaced 20 metres apart. The deposit is approximately 390 metres long, 10 to 40 metres wide and up to 45 metres deep, and is generally confined to the Athabasca sandstone. Uranium occurs as pitchblende, coffinite and uraniferou s goethite."

Jan 1, 1983

Accurately modeling and predicting long term mill throughput is one of the challenges facing metallurgists, geologists and mine engineers in their quest to consistently deliver accurate life of mine business plans. Batu Hijau has systematically improved long and short term mill throughput predictions since feasibility and commissioning in 1999. This has been achieved through a combination of ongoing improvement to the geology ore hardness and grade characterisation model, drill and blast optimisation and, by application of these data to model mill throughput. Batu Hijau has demonstrated the ability to consistently estimate long term mill throughput within ±2% accuracy. Aside from reliably predicting expected production rates with the existing plant configuration, this predictive ability provides a solid foundation for identifying operating and design criteria for short term grinding circuit optimisation and future expansions. This paper discusses ongoing throughput prediction model development at Batu Hijau based on geo-metallurgical characterisation. Also discussed are tools used for day to day production performance management. This includes on line "Mine to Mill" variable monitoring to improve operations parameter ecision making and performance assessment.

Nov 1, 2011

By F. Wirfiyata

"Accurately modeling and predicting long term mill throughput is one of the challenges facing metallurgists, geologists and mine engineers in their quest to consistently deliver accurate life of mine business plans.Batu Hijau has systematically improved long and short term mill throughput predictions since feasibility and commissioning in 1999. This has been achieved through a combination of ongoing improvement to the geology ore hardness and grade characterisation model, drill and blast optimisation and, by application of these data to model mill throughput.Batu Hijau has demonstrated the ability to consistently estimate long term mill throughput within ±2% accuracy. Aside from reliably predicting expected production rates with the existing plant configuration, this predictive ability provides a solid foundation for identifying operating and design criteria for short term grinding circuit optimisation and future expansions.This paper discusses ongoing throughput prediction model development at Batu Hijau based on geo-metallurgical characterisation. Also discussed are tools used for day to day production performance management. This includes on line ""Mine to Mill"" variable monitoring to improve operations parameter decision making and performance assessment."

Jan 1, 2012

By B. M. Das, D. B. Cross

"In June 1983, the Computer Applications and Process Control Committee (CAPC) of the Canadian Institute of Mining and Metallurgy (CIM) circulated a questionnaire to coal mining, exploration and consulting companies in Canada to determine the industry's level of interest in holding a workshop-style meeting to introduce company personnel to ""state-of-the-art "" computer systems designed to carry out specific technical and management junctions. It was necessary to conduct the survey to determine the specific fields of application and the nature of training which are of most interest.Almost universally, the companies expressed interest in computer workshops and training for applications in the Canadian coal industry. The survey showed that all categories of personnel felt the need for some sort of training. Areas of specific interest identified were: exploration and geology, mine design, reserve calculations, coal mining technology, coal preparation, rock mechanics, ventilation, financial planning, and process simulation. The details of this survey together with an assessment of the significance of computer applications in the Canadian coal industry are presented in this paper."

Jan 1, 1986

By N. Hwang

There has been increasing interest in the use of robotic machines, and several prototype robotic machines have been developed to automate the grit-blasting process for the purpose of steel bridge maintenance. To utilize such a robotic grit-blast machine effectively, the first consideration is automating the determination of the rust surface area to blast, on the basis of standards of practice, in a rapid manner. This study aims to propose a method to rapidly and accurately determine the rust surface area on steel bridges to blast, with consideration for the standards of practice, from images acquired via a blasting machine. The first step is to perform a color space conversion to transform the input image from a red/green/blue (RGB) color space to a hue/saturation/intensity (HSI) color space. The next step is to detect the presence of rust, using pixel-level classification via the C4.5 decision tree algorithm. Then it is necessary to confirm the blasting area by verifying whether the rust detection result satisfies the specified criteria on the basis of standards of practice. The proposed method was validated on 39 test images with various characteristics with respect to the degree of rusting and rust distribution type. The experimental results showed that the average accuracy rate of rust area classification was about 97.63%, and the success rate of the final decision of blasting area determination was 100.00% for 39 test examples. The whole processing time took an average of only 0.86 seconds per image. The preliminary results demonstrated that the proposed method not only determined whether rust was present in an image and the amount of rust but also indicated whether blasting was necessary, and, if necessary, it rapidly specified the rust surface area that should be blasted on the basis of standards of practice. The proposed method could be successfully incorporated into a robotic grit-blast machine.

Aug 1, 2013

By C. A. Rowland

"Plant owners and operators, plant designers and grinding mill manufacturers are giving much attention to the design and manufacture of autogenous and semi-autogenous grinding mills, particularly the mills that have large diameters and draw power up to 10,000 hp and greater. Reliable designs giving long operating lives are required in today 's ore processing plants.This paper reviews bench-scale and pilot-plant testing to determine first if the ore is suitable .to be ground by these methods and then reviews the data obtained from pilot-plant testing that is used to select the mills and the grinding circuit. The paper then discusses the use of the pilot-plant results to design the mills. The most important pilot-plant data used for mill design are power and the amount of ball charge to be used. The mill size selected is a combination of these factors. Pilot-plant data not only establish power requirements, but can be used in the selection of the type of drive, variable speed or fixed speed, and the operating procedure to be followed. This leads into the mill control circuit to be used. The total charge in the mill, the type of drive and mill discharge arrangements are needed in the calculation of stresses and bearing loads. Conclusions reached from pilot-plant work are used to obtain data for process design, and autogenous and semiautogenous mill design should be part of any test program incorporating either or both of these grinding methods."

Jan 1, 1981