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By P. R. Taylor

Batch leaching experiments have been performed to study the kinetics of galena leaching in fluosilicic acid solutions with oxidants. Variables studied included: fluosilicic acid concentration, oxidant type, oxidant concentration, particle size and leaching temperature. It was found that hydrogen peroxide was the most effective oxidant, compared to the others studied, and the effect of the oxidant concentration on the leaching behavior of galena was very significant. Also, decreasing the particle size and increasing the leaching temperature increased the extraction rate. The initial, apparent activation energy was calculated to be 11.72 kJ/mole (2.8 kcal/mole) and suggested that galena leaching in fluosilicic acid solution, with hydrogen peroxide as an oxidant, may be controlled by fluid film mass transfer initially. The reaction appears to be retarded by the formation of elemental sulfur and the sulfur oxidation becomes a major resistance to the overall leaching reaction.

Jan 1, 1992

By Ralph H. Nafziger

The Bureau of Mines, in cooperation with the Idaho National Engineering Laboratory, has electroslag melted a V-5Ti-5Cr alloy using a fused CaF2, flux. The alloy is a candidate for use in future fusion reactors. One objective of this research was to evaluate the feasibility of the electroslag melting process in separating simulated radioactive isotopes from the V alloy to demonstrate recyclability. Small amounts of Ca, Y, and Mn were added as surrogates for radioactive isotopes. Results showed that this vanadium alloy can be electroslag melted satisfactorily. The impurities added intentionally were removed or decreased successfully. Among the major alloying constituents, Cr was retained but there were some Ti losses. The latter may be controlled with process refinements. This research suggests that the electroslag melting process could be a suitable method for recycling V alloys after use in future fusion reactors, or for processing other reactive metal alloys with more immediate applications.

Jan 1, 1996

By Timothy A. Clancy

In support of research on forming ceramics from mining and processing wastes, the Bureau of Mines tested various commercial refractories to evaluate their resistance to melts of these wastes. Sixteen refractories of various types were exposed in slag erosion tests to two siliceous waste melts with Si02/CaO ratios of 4.0 and 2.2, The extent and nature of slag attack were then determined for each refractory. The nature of slag attack was investigated through scanning electron micrographs and microprobe elemental distributions. The refractories that performed best in resisting attack by the melts were high-alumina types, and of the refractories tested, the most resistant was a 90-pct-Al203, 10-pct-Cr203 refractory.

Jan 1, 1983

By Tamal K. Ghosh

In this study, the QEMSCAN technology is used to acquire quantitative modal, textural, mineral association and liberation data on different products generated from with or without washing, fractionation by size and density using screens and heavy liquids/panning, which has provided significant information on the quality and beneficiability of four categories of low Grade iron ores from Jharkhand-Orissa region. The deposit of low Grade iron ore has been categorized into four categories viz. Grade-I with <45% Fe(t) a) containing shale rich type and b) BHJ rich type; Grade-II with 45-55% Fe(t) and Grade-III with >55% Fe(t) containing conventional flaky, hard, kanga, lateritic, shale and BHJ litho/ore types in varied proportions. Mineralogy is similar across all samples being hematite, martite, goethite, kaolinite and gibbsite. Banded Hematite Jasper has difficult liberation characteristics due to highly compact banded mode of silica mineral occurrence with hematite. In all categories, the grade dilution is by the presence of 1) ?Discrete gangue rich litho types? at lump size and 2) ?Within ore types?. The second type of grade dilution contains coating of gangue phases around the iron ore minerals and different degree of locking of gangue phases within iron ore minerals. Further characterization and beneficiation assessment details are discussed in this paper.

Sep 1, 2012

By M Goers, M Almond

"The use of reverse circulation (RC) drilling for grade control sample collection was selected by the Pueblo Viejo Mine Geology department at the recommencement of the operation in 2010. This method was selected because it allows: for multi-bench drilling (60 m hole depth, four benches of mining) to aid mine planning and provide a detailed close spaced drill data comparison with the reserve model angled drill holes to optimise the drill hole interception of the vertically controlled mineralisation dry sample collection in areas of excessive surface and groundwater mining operations to commence with the long assay return period (due to the need for the samples to be shipped overseas for analysis) until the on-site laboratory is operational.To date, 118 302 m of drilling has been completed throughout the operations of two open pits: Monte Negro and Moore. Two drill rigs (contractor and site-owned and operated) with three generations of sampling systems have been used to date. Throughout the drilling a 20 per cent quality assurance, quality control (QAQC) sample check (blanks, field duplicates and standards) have been used to check the drilling and laboratories performance. In addition, a total of 1104 fines samples were collected to compare the drill chip samples collected and the fines lost with two of the sample systems used.The drilling to date has highlighted the need for a complete and coordinated system to be used before sufficient confidence in the quality of the samples collected is achieved.The complete system must be set-up and coordinated to obtain the best quality sample possible. This complete package includes: drill bit size and shape for the rock being drilled and mineralisation targeted face sampling hammers with the correctly sized hammer shrouds sample hose routing to reduce sample flow turbulence and choking blow-down valves to eliminate drill hole water that has entered the drill string during rod changes correct drilling techniques targeting sample quality a sample system that captures the fines for inclusion into the sample.These improvements can be obtained without reducing the drilling rates.The measurements required to demonstrate the improvement in the sample quality will be the focus of future work within the department.CITATION:Goers, M and Almond, M, 2012. Bit to bag - The importance of a total coordinated system in reverse circulation drilling, in Proceedings Sampling 2012, pp 65-72 (The Australasian Institute of Mining and Metallurgy: Melbourne)."

Aug 21, 2012

By E. DeLilia

For the past 30 years, surface mines have moved toward more highly mechanized, automatic systems that continuously mine overburden and ore to in-crease productivity, lower operating costs and minimize manpower needs. To achieve these goals, mine operators must be involved in every step of the machine procurement process. Several factors are involved in making the machines operate economically and efficiently: ? Prudent engineering. ? Proper planning. ? Realistic feasibility studies. ? Effective specification. ? Thorough training of the mine personnel.

Jan 1, 1995

By Eric Pirard

Theoretical studies carried out on shape analysis supply mathematical tools to analyze the influence of grain shapes on ore beneficiation. In the case of statistic images like those encountered in applied mineralogy parametrical and harmonical analysis methods are used. It is important that the shape parameters are adapted to the specific processes involved in ore beneficiation, while remaining easy to manipulate. The inertia parameters are considered in the scope of granulometric and gravimetric processes It appears that they are able to distinguish between the resulting products where very popular shape parameters are not. The measured statistics are analyzed through discriminant analysis procedures in order to estimate the importance of morphological differentiation and the aptitude of shape parameters to account for this.

Jan 1, 1989

By M. L. Trépanier

"Engineering and technical services are supplied by the Engineering Department, located at Thetford Mines, Quebec, approximately 60 miles southwest of Quebec City. The department serves the three operating mines in the Thetford area, the Asbestos Hill mine at Putuniq, Nouveau Quebec, and the Nordenham plant at Nordenham, West Germany. The Engineering Department is responsible for supplying the following services. 1. Administration and coordination of capital projects. 2. Engineering, design and drafting services for in-plant changes or improvements. 3. Preparation of geological plans for mine planning and ore reserves determinations. 4. Short-, medium- and long-term mining plans. 5. Rock mechanics studies and monitoring. 6. Grade control monitoring. 7. Environmental control engineering and construction. Details of the organization and services rendered will be the basis of the paper."

Jan 1, 1976

By Angus D. Campbell

"IntroductionThe subject assigned to me tonight gives unlimited scope. The material available is so voluminous and leads into so many ramifications, and the memories of the Camp are so vivid and treasured, that it is difficult to decide just what to use. Then, too, the geologists are the story-tellers of our tribe - I am only a hard rock miner.Members of the Cobalt Branch and Cobalters everywhere will agree without question that this Cobalt camp has been the greatest of all influences on Canadian mining. To those who do not know Cobalt, our opinion may seem prejudiced and our statement exaggerated.Be that as it may, discussion on this subject can be profitable, since it is worthwhile now and then to think on 'whence we came' and 'where we are going'.In the revival of interest in the Cobalt camp, we hope our guests may feel some of the old Cobalt Spirit, which has become the Spirit of the North.Visitors may even, while here, catch a glimpse of that whimsical little guardian spirit of the camp - the original goblin, the Kobold - for which Cobalt was named.While Kobold brings that good luck which plays so important a part in mining, he can have his evil moments, as in his original German home. There, when he made the silver disappear from their good ore, they cursed the grey ore, calling it Kobold.Although this little goblin bas frequently upset our best mining plans and geological calculations, be has played the game as well. He placed •some silver on the surface, and when he hid ~t at depth he left dues .for its finding. He has rewarded many who sought his treasure and is still rewarding those who have persevered and had faith in him. t:lis influence and that of Cobalt camp has probably had a greater influence on your work and your mining areas than you realize"

Jan 1, 1950

"SART technology is a useful tool for improving the economics of gold recovery from certain types of complex gold ores. SART liberates cyanide consumed by base metals such as copper, zinc and nickel, and enables the newly freed cyanide to be recycled to precious metals leaching while producing high-grade base metal sulphide concentrates for sale. The benefits of SART include the reduction in cyanide consumption, avoidance of cyanide destruction costs, minimization of risks of environmental non-compliance due to residues of cyanide destruction reporting to mine effluents, and generation of extra revenue from the sale of base metal concentrates. Concerns with SART typically include uncertainties around capital and operating costs and proper integration of SART into the overall metallurgical flowsheet. This paper presents two case studies addressing these concerns. The first involves actual costs of the full scale SART integrated into a gold heap leach operation and treating up to 500 m3/hr of leach solution at a mine in Mexico. The second involves field pilot testing and a preliminary cost estimate for integrating SART into a silver mine in Peru using Merrill Crowe.INTRODUCTION One of the current trends in the gold industry globally is the increasing importance of complex polymetallic gold deposits as discoveries of large Carlin type gold deposits become increasingly rare (Sceresini, 2005). The presence of cyanide soluble copper and zinc in complex gold deposits necessitates changes in traditional gold extraction metallurgical flowsheets. One of the tools available to the industry to help deal with interferences of cyanide-soluble base metals in gold extraction is the SART (sulphidization-acidification-recycling-thickening) process. SART breaks the weak acid dissociable (WAD) base metal-cyanide complexes, precipitates the metals as high-grade sulphide concentrates and makes the freed cyanide available for recycle. Although SART is a commercially available technology, it is still relatively new to the industry. Fewer than ten (10) full scale plants have been constructed in the past couple of decades. Some of these SART plants are small, most are located at remote sites, and the majority have not operated on a continuous basis. This has resulted in a general lack of information in the industry about the true costs, operability and metallurgical performance of SART. BQE Water has been involved in the design, construction, commissioning and operation of large scale SART plants in Mexico, Turkey and Chile and has conducted field testing programs as part of the technical assessment of SART integration into various metallurgical circuits. Having built and operated numerous plants utilizing selective sulphide precipitation of heavy metals, BQE Water has gained unique insight into the design and control of the sulphidization stage of SART to minimize costs and ensure high efficiency in cyanide recovery."

Jan 1, 2017

By E. Oshilna

The Mitsubishi process has many advantages pertaining to economical and environmental matters. These advantages have led to the installations of the Mitsubishi process in constructing new smelters: The Mitsubishi process utilizes highly oxygen enriched blast air and uses a special lime slag in the C?furnace. These characteristics change the . distribution of Impurities from other processes which use P.S. converters, Recently an Increased amount of secondary materials which contain impurities Is being treated at Naoshima Smelter. In order to cope with an Increment of the Impurities load and maintain the cathode quality, many Improvements have been Implemented. This paper discusses the impurities behavior In the Mitsubishi process and describes the measures taken to treat an Increased ?amount of secondary materials:

Jan 1, 1998

By Duong Huu Hoang, Nathalie Kupka, Urs A. Peuker, Martin Rudolph

"The froth ability, froth stability and the froth structure are strong influences in flotation process i.e. on water recovery, bubble size, entrainment of gangue particle, flotation rate constants, grade and recovery. The labscale flotation of rich apatite ore with a high mass pull leads to significant changes in pulp and froth properties over time. The froth stability decreases with increasing the flotation time. These changes can be related to different solid contents, reagent concentration, froth heights and bubble size distributions. This study presents the results from froth studies and discussions on the particle size of fully liberated silicates and degree of entrainment based on automated mineralogy size-by-size analysis. The change of entrainment in a rich apatite ore batch flotation with time will describe more precisely by measuring froth properties using a Dynamic Foam Analyzer. It is concluded that the degree of entrainment is not only dependent on particle size but also the pulp density due to its effect on particle settling and also froth properties in varying resistance to particle drainage. Furthermore, entrainment models are applied to predict the effect of size, flotation time on entrainmentINTRODUCTIONFroth flotation belongs to the group of heterocoagulation separation techniques. Froth flotation is classically divided into two active zones, the pulp zone (where particle collection occurs) and the froth zone. A schematics drawing of the interaction between both zones is plotted in Figure 18 (Yianatos and Contreras, 2010). In froth flotation, the collision probability in the collection zone is governed by the physics of the process or hydrodynamics (Wills and Finch, 2016). The true flotation event in the pulp occurs when the hydrophobic valuable mineral particles collide with bubbles and formation of a stable particle-bubble aggregates moving upwards against gravity to the froth phase (Yianatos et al., 2009)."

Jan 1, 2018

By Richard A. Leiby

The recycling of lead-acid batteries in the United States has become a challenge as to how to balance ever increasing environmental regulation and cost with efficient operations. East Penn&apos;s captive secondary lead smelter has developed into a recycling facility producing lead, polypropylene, sulfuric acid, ammonium bisulfite, and non-hazardous discard slag. The emphasis has been to design a facility to comply with environmental regulations, to eliminate wastes, and to produce products, while at the same time, continuing to supply the company&apos;s battery manufacturing raw material needs.

Jan 1, 1993

By Osvaldo A. Bascur

Most mining and metallurgical plants have developed predictive maintenance policies based on statistical analysis and special techniques, like vibration analysis, oil and lube analysis for critical equipment. Process control strategies have also been installed in several metallurgical sites. These control strategies require instrumentation maintenance from local personnel. The availability of real time and process history to identify the most critical part of the processing system from mechanical integrity is a must for global plant optimization. Specialized performance control monitoring algorithms are required to justify their existence and contribution to the bottom line. Emerging technologies are combining these techniques into a single total plant system. Tools are required to assist in troubleshooting and adapting these process control instruments and strategies. The key is the plant equipment and process control availability and utilization rather than just maintenance.

Jan 1, 1997

By J. M. Harrison

FIELD PARTIES of the Geological Survey of Canada have, in recent years, mapped several areas east and northeast of Flin Flon (9, 10, 12, 13, 14, 15, 118) (1). In all these areas the mineral deposits show a close geographical relation to faults although the immediate control of most of the known ore deposits appears to be folded structures in the rocks (8, 11, 18, 19). Air photographs and published geological maps were studied in order to ascertain whether or not the mineral deposits in the Flin Flon-Snow Lake mineral belt as a whole show any spatial relationship to faults. It was found that most of them do show a distinct geographical association with faults, or with topographic features that may be faults. It is further apparent on air photographs that a major lineament, for composite of lineaments, follows approximately the contact between gneisses and schists of the Kisseynew complex on the north, and Amisk volcanic rocks on the south. However, this Kisseynew lineament is not continuous and, especially in the eastern half of the district, it is exceedingly irregular in plan. Parts of this lineament have been mapped as faults (9, 10, 12, 14), other parts have been shown as stratigraphic contacts (1, 2, 21, 27), and still other parts have not been studied except by reconnaissance methods. It is suggested that the Kisseynew lineament may be due to a deformed fault that extends easterly from a point about 25 miles west-northwest of Flin Flon to a point at least 10 miles northeast of Wekusko lake and that the mineral deposits.

Jan 1, 1951

By Robert J. Coutts, Dan A. Payne

"The Broadmeadow mine is a punch longwall mine owned and operated by BHP Billiton Mitsubishi Alliance (BMA) in the Bowen Basin of Queensland, Australia. In 1999, an exploratory adit was driven as part of the feasibility study for the establishment of the mine. Subsequent development of the mine in 2004 started some distance away from the initial test adit. Ten years later, the trial adit would be used as the headgate of the 5'h longwall panel. However, multiple roof falls had occurred in a heavily jointed area over a distance of 1, 000 ft (300 m) during the past 10 years. Due to the immediate coal roof, low stress environment and time, some of these falls had progressed to 38 ft (11.5 m) above the mining floor. As a result of the extensive work involved and safety implications of trying to recover the roof falls conventionally, a strategy was developed to fill these roof falls with a cement based product from the surface, down boreholes, and redrive the roadways through the consolidated roof fall material. This paper describes the process of rehabilitating these roadways, the results when the roadway was redriven and the headgate performance as the longwall mined through the area.INTRODUCTIONBMA operates 7 open cut and 2 underground mines in the Bowen Basin of Queensland, Australia producing over 50 mt per year of high quality coking coal. As a result, BMA has established over 150 miles (250 km) of open cut highwall.Broadmeadow Mine is a punch longwall mine located 22 miles (35 km) north of Moranbah in Queensland, Australia on the western limb of the Bowen Basin Coal Measures (Figure 1). Broadmeadow Mine commenced development in 2004 and began longwall operations in 2005. Broadmeadow is currently completing the fifth longwall panel and produces over 4 Mt per year of high quality coking coal. Mining is undertaken in the Goonyella Middle Seam, which is 21 to 25 ft (6.5 to 7.5 m) thick in the current mining area.The mine layout required the use of an old exploratory gateroad as the headgate of its 5th longwall. This gateroad had experienced numerous large roof falls and required extensive rehabilitation."

Jan 1, 2010

By G. Goodall, R. Jabbar, S. Muinonen, A. Cummings

"Glencore’s Sudbury Integrated Nickel Operations in Falconbridge, Ontario, has been in operation since 1930. Many new technologies and practices, now common in the industry, have been implemented at the site and contribute significantly to the industry’s understanding. Since the last update on the Smelter operation published at the NiCo 2005 conference, the Converter Aisle has undergone significant changes in the operation of vessels. The Aisle continues to consist of 4 Peirce-Smith converters, but the Slag-Make Converter, and the Slag Cleaning Vessel have been re-tooled or re-built as Hybrid Vessels (HV), each generating matte for the two Finishing Converters and clean slag for disposal. The complicated scheduling and the overall benefits to the Smelter are reviewed here as part of the on-going tradition of industry support.INTRODUCTION The Glencore Nickel Sudbury Smelter operates a Roast Reduction Smelting (RRS) flow sheet with a specialized Converter Aisle operation that maximizes metal recovery to Bessemer matte. The main process equipment consists of a pair of Fluid Bed Roasters, a submerged-arc Electric Furnace and four Peirce-Smith converting type vessels (Figure 1). In the RRS flow sheet, concentrate is roasted with air to remove sulphur as SO2. Calcine from the Roasters is mixed with petroleum coke upon addition to the six-in-line rectangular Electric Furnace. The coke back reduces the metallic oxides, producing a matte and a discard slag.Gases from the Roasters are sent to a single pass absorption Acid Plant where the SO2 is converted to acid. Under the previous operating targets, approximately 70–75% of the sulphur in the incoming concentrate was fixed as acid with the balance going to the Electric Furnace in calcine for Bessemer matte production. Off-gases from the Electric Furnace and Converters are combined in a balloon flue, treated for particulates in electrostatic precipitators and discharged to the Smelter stack without any SO2 fixation."

Jan 1, 2017

By J. F. T. Agapito

Experience at Energy West Mines in the Wasatch Plateau Coal Field, Utah, has shown that longwall face bursts occur mostly near the tailgate when extracting the third adjacent longwall in a panel section where depths exceed 610 m (2000 ft). It is believed that this is due to a combination of cover depth and side abutment stresses created by the widening of a pressure arch formed by interlocking and bridging of large blocks of" very competent strata. The 60-m-thick (200 ft) Castlegate Sandstone probably plays a key role in pressure arching. This paper presents a back-analysis of the location and magnitude of the stresses associated with face bursts that occurred when mining the 7th Right Longwall at the Deer Creek Mine. Improvement of these conditions may be achieved by widening the longwalls to attain critical subsidence width sooner while mining the second long-wall, and to reduce stresses at the face. Wider longwall faces, however, increase the chance of sandstone channel interception often associated with bursts. Satisfactory mitigation of face bursts beyond cover depths of 610 to 670 m (2000 to 2200 ft) may be difficult without using destressing techniques. The hydraulic fracturing/liquid infusion technique seems to offer the best possibilities for application in longwall mining.

Jan 1, 1997

By Claudia Gasparrini

Uranium occurs in a variety of minerals, the more common primary ones of which are uraninite-pitchblende, coffinite and a group known as the complex multiple oxides. Identification and description of the uranium-bearing and associated minerals in ore samples may give a preliminary indication of the potential economic importance of the deposit and may also suggest initial approaches to metal extraction. The present paper reviews the common uranium minerals, describes their manner of occurrence and compares the types of deposits with which they are associated. Methods and techniques for their identification are described and their leaching characteristics discussed.

Jan 1, 1981

By Rainer Antretter

"THE CHALLENGE The 14km long, Arlbergtunnel, closed for public traffic during summer 2015, receiving a comprehensive and substantial renovation from 2015 to 2017. The main works discussed here, carried out during 2015, comprise 37 drill and blast SEM/NATM emergency escape tunnels from road level to the ventilation duct plenum have to be constructed as well as eight additional lay-by niches and three transformer tunnels. This presentation comprises the construction ventilation design, designed according to national regulations, suitable for 150 employees working 24/7 simultaneously at more than 40 single working sites lined up along the tunnel. The ventilation-system chosen was utilising two existing shafts for intake/discharge and a cross passage to surface, to handle a total fan power of 1.600kW. DESCRIPTION OF RENOVATION WORKS Linking Tyrol and Vorarlberg, two Federal States of Austria, the Arlbergtunnel is a single tube two-way road tunnel with vent duct plenum, constructed in the mid-1970s. According to latest EU legislation, additional escape exits have become obligatory. The existing seven cross passage links to the adjacent Arlberg Railway Tunnel, with average spacing of about 1.500m constructed in 2007, an additional upgrade to shorter escape spaces of approx. 400m was now required to comply with the updated legislation. Additional transformer tunnels, lay-by niches and small niches for emergency maintenance use, cleaning and other purposes, as well as a the installation of a new fire main in the invert, coupled with the simultaneous replacement of virtually the entire power and signaling cables, generated several dozen small and large single sites distributed along the 14km of tunnel.Purpose of the 37 walkable emergency escape tunnels is to reach the “upper deck” of the Arlbergtunnel, the vent duct plenum. These have an 180deg curve in plan, inclined at 10% and approx. 60m (65yd) long tunnels, excavated using drill and blast method starting from road level and working upwards to the level of an “intermediate soffit”, the vent duct plenum in the crown of the tunnel. The vent duct plenum is separated into a fresh air part and an exhaust air part, shown in Figure 1. The escape tunnels end with a pressure door in the fresh air section of the ventilation duct plenum. From there illuminated signs show the shortest escape route to the safe area between the road tunnel and the railway tunnel, as shown in Figure 2."

Jan 1, 2016