Search Documents

The 1965 Lignite Symposium, the Louth in a series and the third sponsored by the University of North Dakota and the Bureau of Mines, was held at Bismarck, N. Dak., on April 29-30, 1963. These symposia provide a forum for those interested in the technology and utilization of solid fuels, especially lignitic coals. As part of the meeting, a 200-mile field trip was taken including; inspection of (1) the 200-megawatt, pulverized lignit-fired Leland Olds plant of Basin Electric Power Cooperative, under construction near Stanton, N. Dak.; (2) the site of the Glunharold mine of the Truax-Traer Coal Co., Division of Consolidation Coal Co., where a wheel excavator was being assembled; (3) the operating Beulah mine of Knife River Coal Mining Co., subsidiary of Montana-Dakota Utilities Co., near Beulah, N. Dak.; and (4) the 400-megawatt, hydroelectric Garrison Dam powerplant, near Garrison, N. Dak.

Jan 1, 1966

By Khosrow Ebrahimi

We document the occurrence, mineralogy and firing properties of magnesite from hydrothermal deposits in the upper Cretaceous ophiolites of Eastern Iran. These deposits occur as thin veins of nearly pure cryptocrystalline magnesite with only trace amounts of quartz, calcite, and dolomite. Ratios of CaO/SiO2 in the bulk ore are variable. The composition of dead-burned magnesite from these deposits, calcined at different temperatures and durations, is predictable from phase equilibria. Textures of the calcined magnesite were studied by SEM; results show that the principal impurites produced during calcination are forsterite, monticellite, merwinite, dicalcium and tricalcium silicates, and that these are located principally at triple junctions of the periclase crystals. The size of periclase crystals increased with temperature and duration of calcination and the amount of periclase-periclase grain contacts was reduced by increasing the concentration of impurities in the starting products. EPMA show: 1) that CaO and FeO contents in periclase increase steadily with an increase in the CaO/SiO2 ratio and the FeO content of the bulk ore, respectively, and 2) that limited solid solution exists between impurites. This study demonstrates that high quality dead-burned magnesia refractories can be produced from the Iranian magnesite with low CaO, SiO2 and FeO contents.

May 1, 2004

By Pinai Mungsantisuk

Keywords: Pd-Ni alloys, Pd-Fe alloys, Pd-Co alloys, Magnetostriction, Magnetic Properties The presence of congruent melting minima, the occurrence of ferromagnetic transition over a large composition range, and FCC type crystal structure make Pd-Ni, Pd-Co, and Pd-Fe based systems attractive candidates in our search for materials with no rare-earths, large low-field magnetostriction, and good mechanical properties. The presence of paramagnetic-ferromagnetic transition over a broad range of composition also provides opportunity for fundamental studies. In this work, we have examined the magnetic and magnetostrictive behavior of Pd-Ni, Pd-Co, and Pd-Fe alloys over the entire composition range. Alloy sample rods were prepared by arc melting and casting. X-ray diffractometer was used to obtain lattice parameter data. Magnetostriction was measured along the rod axis using strain gages. Magnetic properties were measured using a vibrating sample magnetometer.

Jan 1, 2005

By N. I. Aziz

The importance of using disc cutters for rock excavation is reflected by their wide application in hard rock cutting machines such as tunnel boring machines and raise borers. The forces involved in the cutting process are those due mainly to thrust and rolling forces and are greater than that required by cutting picks. An interesting feature of cutting with discs is the formation of surface crushing, surface and sub-surface chipping and primary crack formation. Experimental, as well as analytical, work has been carried out to determine the optimum spacing between the disc cutters to control primary crack orientation. Wedge bit indenters were used to simulate disc cutters. The paper concludes by proposing a new approach to rock excavation by hybrid cutting based on controlling the primary crack orientation.

Jan 1, 1992

By S J. Loach

Geological reconciliation is an indispensable part of BHP Billiton’s Western Australian Iron Ore (WAIO) operations. Since 2009 our reconciliations have been calculated in a single, centralised sequel-server database. This system draws data from across our operations and calculates a hierarchical sequence of reconciliation factors that span the company from the smallest grade control (GC) block to the whole of WAIO. It then presents the results using sophisticated graphical reporting tools.The initial motive for developing WAIO’s reconciliation system was to meet corporate compliance and public reporting requirements. The ability to validate our resource and reserve models by comparing their estimates of tonnes and grade with production figures remains the system’s principal function; however, as the system has matured, we have significantly developed its ability to support the improvement of various technical activities within the business. For example, the system can now calculate and report reconciliation factors for different resource classifications, short-term planning models and geometallurgical estimates.More recently, great emphasis has fallen on the system’s ability to detect and warn of possible geological issues that may pose a risk to either production schedules or product quality. We envisage a future where automated analysis of our large historical data set will enable high-risk conditions within future mine plans to be detected and highlighted.In all of these ways geological reconciliation plays an important role in contributing to this company’s financial and operational resilience.CITATION:Loach, S J, 2017. The development and future of BHP Billiton’s Western Australian iron ore geological reconciliation system, in Proceedings Iron Ore 2017, pp 415–422 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Jul 24, 2017

"Quang Ninh province is located in the north east of Vietnam and the coal mining in the province generates two thirds of the province’s GDP. The coal is extracted from both open pit and underground mines for the country’s complete coal export and by a share of more than 90% for domestic coal usage. Overburden generated through open pit mines is piled up nearby in the form of large waste rock dumps. The side-hill fill dumping near open pit mines is the source of environmental degradation in the region. Among the current problems at solid waste rock dump sites are dust emissions during and after dumping as well as Acid Rock Drainage (ARD). One of the major existing problems at waste rock dumps is dump stability (comprising erosion, sliding and subsidence issues). The RAME R&D project (Research Association Mining and Environment in Vietnam) is - among other activities - actively involved in the research for stabilisation and rehabilitation of mine waste rock dumps in Vietnam in the form of several sub-projects. The Institute of Mining Engineering I of RWTH Aachen University is leading the sub-project of mine waste dump stabilisation in co-operation with Chair of Geotechnical Engineering and Brenk Systemplanung GmbH. Mine waste dumping in the form of layers as an alternative to the side-hill fill dumping is expected to bring up environmental and economical benefits by minimising the problems of dump sites with the contribution to a sustainable development. Reduction of the post construction settlements, long term stable dump profile with minimum erosion, improvement of material parameters for geotechnical slope stability through compaction from hauling trucks as well as economical evaluation of new dumping concepts are the areas of the current research. The project has been financed by German Federal Ministry for Research and Education (BMBF). The ultimate aim of the sub-project is the compilation of the project results in the form of a "Best Practice Guide" and software based "Decision Support System" for planning and management of solid mine waste dumps."

Jan 1, 2011

By M. Leroux, S. R. Rao, J. A. Finch

"Poor Pb-Zn selectivity during Pb flotation in laboratory tests on a Mississippi Valley-type Pb-Zn ore was traced to apH effect. In the pH range, 9.5 to 11.0 sphalerite floated readily without copper activation. Compared to sphalerite flotation with copper activation this procedure gave equivalent selectivity but reduced flotation rate.Possible mechanisms of this sphalerite flotation without copper activation are discussed. Activation by Fe(OH)2 is suggested, the Fe- + ions being derived from superficial oxidation of pyrite in the ore. IntroductionGalena and sphalerite commonly occur together. A typical procedure, using xanthate collectors, is to float the galena first, at pH - 8, followed by flotation of sphalerite after activation with copper (II) sulphate at pH - 10 (to depress pyrite).Flotation tests following this procedure in an undergraduate laboratory course with a Pb-Zn ore from Polaris failed to achieve consistent selective flotation of galena. Occasionally a considerable amount of sphalerite, even though unactivated with CUSO4, floated. This was traced to accidentally high pH. A systematic study was carried out which revealed that sphalerite floated readily in the pH range 9.5 to 11.0 without activation by CuSO4 This paper describes the results of the study and discusses a possible mechanism of this flotation of sphalerite."

Jan 1, 1987

By G. S. Hill, B. J. Huls

This paper on coarse particle recovery (CPR) summarizes a process to capture coarse particles that are not recoverable by regular flotation. Several porphyry copper operations in the world operate analogous circuits that recover non-floated copper from tailings; however, the case presented here is unique in that extensive underlying test work has allowed the authors to elucidate some fundamental principles behind recovery enhancement. This paper discusses an overview of the flowsheet that is proposed to Minera Escondida Ltda., the nature of copper in the feed to the CPR circuit, and the various unit operations within the recovery circuit.

Jan 1, 2006

By Howard W. Wainwright

This bibliography was compiled by the Bureau of Mines as part of an investigation into the possible utilization of low-temperature coal-tar bases. The bibliography consists of literature and patent references from about 1945 to 1961 and is divided into the following headings: Analysis and Composition; Production, Synthesis, Reactions, and Utilization; and Separation, Purification, and Properties. Although over 1,000 references are included, no attempt was made to insure a comprehensive survey. The literature and patent references are arranged alphabetically by author or patentee. When several publications have the same author they are listed in reverse order of age, with the newest first. An author index is included because secondary authors are not cross-indexed. In almost every instance, the entry is accompanied by a Chemical Abstracts reference for those interested in locating an abstract of the original paper.

Jan 1, 1962

? CONSTRUCTION AND MINING COSTS ARE HIGH IN THE ARCTIC ? VERTICAL KIMBERLITE PIPES WITH HIGH STRIP RATIOS ? SITE SPECIFIC GEOMETRIC CONSTRAINTS ? OPEN PIT FOLLOWED BY UNDERGROUND MINING ? HIGH KIMBERLITE UNIT COSTS TRACK INSTALLED ON PIT WALL ? INTENDED TO REPLACE MAIN HAUL RAMP ? 5 MIN HOIST CYCLE TIME ? KEY ADVANTAGES - REDUCED CYCLE AND STRIPPING RATIO ? TECHNOLOGY EXISTS IN OTHER APPLICATIONS

May 1, 2003

By F. H. Willcox

This publication is the third of a series of reports on hazards and the prevention of accidents at blast-furnace plants that is being published by the Bureau of Mines, Technical Paper 106a being the first and Technical Paper 136b the second of the series. This bulletin, which is arranged in three parts, treats of the causes and prevention of blast-furnace breakouts, explosions, and slips. The first part discusses blast-furnace breakouts, the hazards therefrom, causes, and features of furnace design and methods of operation that tend to prevent breakouts or lessen their number, and points out safety measures to be adopted. The second part takes up the theory and causes of gas explosions at blast-furnace plants and reviews the better methods in use for handling gas. The third part analyzes the causes of hanging and scaffolding in blast furnaces, with the resulting slips that frequently cause injury to the plant and danger to the workmen, describes features of construction and furnace design and methods of operation employed to prevent hanging and slipping, and suggests precautions and safeguards.

Jan 1, 1917

By Monique Pharand, Jeet Basi, Simon Hille

"High quality activated carbon is essential in the recovery of gold in Carbon-in-Leach (CIL), Carbon-in-Pulp (CIP), and Carbon-in-Column (CIC) circuits. Goldcorp’s Campbell complex at Red Lake Gold Mines (RLGM) experienced a period of low soluble gold (Au) recoveries during Q3 2013, during which time the processing plant saw higher than typical Au grades in the CIP tails solution stream. A technical review identified that the CIP circuit may be experiencing a carbon-fouling issue. To further understand the degree of fouling, and to troubleshoot the low recovery problem, samples of carbon were collected from the CIP, elution, acid wash, and regeneration circuits, and submitted for characterization test work. This paper summarizes the steps taken to remedy the carbon-fouling problem at RLGM resulting in increased overall Au recovery.Overview of Red Lake Gold MinesRed Lake Gold Mines is located approximately 450 kilometres northeast of Winnipeg, Manitoba, in Ontario’s western boundary region.All mining is carried out through underground operations, utilizing overhand cut and fill, underhand cut and fill, and long-hole mining methods. Ore types include: silica-replaced carbonate veins with free milling gold, siliceous replacement-type mineralization (rich with arsenopyrite) marginal to veins, broad disseminated sulphide mineralization along major shears, and some minor sulphidized chemical sediment-hosted ore. The operation is supported by two milling complexes: Red Lake, and Campbell.Process DescriptionThe Campbell processing plant's main unit operations consist of grinding, gravity concentrating, flotation, autoclaving, leaching, carbon-in-pulp (CIP), carbon elution and reactivation, electro-winning, bullion smelting/refining and cyanide destruction, and concentrate handling. A schematic of the plant flowsheet is shown in the figure below.BackgroundHigh quality activated carbon is essential in the recovery of gold at many CIP/CIL/CIC processing plants. At RLGM, gold-bearing ore is milled and cyanide is added to leach the gold from the solids into solution. The dissolved gold then comes into contact with activated carbon, and adsorbs onto its highly porous surfaces. Gold is then recovered by separating the activated carbon from the main slurry for further refining. As such, the characteristics and quality of the activated carbon have a significant and direct impact on overall gold recovery."

Jan 1, 2016

By B. Samanta

LHD (load haul dumper) is now used as a loading machine for intermediate mechanization in underground coal mining. For survival in the intense competition in the global business environment in recent years it is essential that LHD machine should be reliable and maintained effectively and efficiently. This paper seeks to study the reliability, availability and maintainability (RAM)of an LHD machine with failure and repair data by Markov modelling. The constraints and reasons for machine unavailability are outlined. The reliability and maintainability of an LHD and its subsystems are evaluated. Possible modification or design alternatives are highlighted. Reliability and maintainability of an LHD system are disappointing. There is room to take decisions on optimal maintenance planning and machine improvement from this analysis. Keywords: reliability, availability, maintainability, Markov model, LHD

Jan 1, 2004

By X Dahe

SLon vertical ring and pulsating high gradient magnetic separators (VPHGMS) possess the advantages of high efficiency and high reliability in beneficiating weakly magnetic minerals. In recent years, models SLon-2250, SLon-2500, SLon-3000 and SLon-4000 have been developed. This paper gives several examples of their applications in oxidised iron ore and ilmenite processing flow sheets to improve iron and ilmenite recoveries.CITATION:Dahe, X, 2017. Recent development and application of SLon vertical ring and pulsating high gradient magnetic separators in the iron ore and ilmenite processing industries, in Proceedings Iron Ore 2017, pp 461–466 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Jul 24, 2017

By B A. Tapp

The minerals industry in Australia is currently regarded as the country's economic saviour; the bastion of economic security. As Fitzgerald (1974) stated, 'Australia's natural endowments in minerals are the envy of most countries of the world'. As a result the proposed new mineral developments are on a scale that hitherto in the sixties would have been completely un-envisaged. It is reported that Australia is poised on the verge of a 16 billion dollar mining-based investment boom: a boom that will see Australia dominate the energy export field, the mineral processing field, and create the 'coal dollar'. This growth scenario has many inherent dangers, and it is the authors' contention that these should be carefully considered before further development proceeds. Two of the major problems related to the mineral industry growth scenario are the predictability of the future metal market, and the energy cost of mining. The latter problem is the one discussed here. The mining-mineral processing industries in Australia currently use about 36 per cent of Australia's primary energy budget. This large energy input is dominated by two major industries, iron and steel and the rapidly developing a1uminium industry. These two combined use over 20 per cent of the total Australian energy budget. In an industry which is export oriented about 96 per cent as expressed in ex-mine value terms û much of the energy input is exported along with the product. The authors therefore urge that serious consideration by the mineral industry be given to the relatively high energy intensiveness of process operations, especially in respect of the aluminium industry.

Jan 1, 1980

By Stephan Großwig, Karolina Nycz, Arne Kindler

"Commonly used anchor monitoring systems are mainly based on the use of anchor force meters. However, experience shows that the reliability of the display of force meters lowers over time. Other measurement and test methods like for example fibre bragg grating method require a comparison with an unloaded optical fibre and give only selective information about the bearing behavior. Moreover the obtained information has to be interpreted. In the following article, first measuring results of an anchor monitoring system based on measurements with optical fibre are presented. The new monitoring system is based on the Rayleigh technology and was used to test the load bearing behavior of the anchor grout body as well as for the evaluation of the grout body condition in concrete-damaging groundwater.INTRODUCTIONThe first fibre optic sensors came onto the market about three decades ago. Initially used as special solutions only in selected cases, now they have found use in almost all areas of technology, especially in areas, where electrical sensor systems reach their limits. The first application examples of spatially resolved fibre-optic sensors in the field of geotechnics have been in existence since the mid-1990s, in projects such as the assessment of the of radioactive repository location sites (Hurtig et al. 1994), for the monitoring of landfill sealing systems (Hurtig et al. 1995) or within the framework of the rehabilitation of mountain farming landscapes (Schreck et al. 1998).The company's first own works in the field of glass fibre measurement technology have been in existence since 1993. The first carried out projects were a monitoring at the Edertalsperre (Dietz et al. 2001), a monitoring with glass fibre tendon at a flood bridge in Carinthia as well as monitoring within the framework of the Storebælt crossing. In all cases, the structure was permanently monitored by means of individual-point measurements. Since 1993 various fibre-optic sensor solutions for geotechnical applications have been introduced to the market (Voet, Glötzl 1996, Hurtig et al. 1994)."

Jan 1, 2017

By Darelle T. Janse van Rensburg

Some of the more recent developments in Paint Technology are solvent free materials. These coatings have mainly been formulated to overcome the negative attributes of solvent-based coatings, i.e. environmental, safety and health risks, potential for solvent entrapment and osmotic blistering, as well as the formation of micro-pores during the curing process. Two solvent free liquid epoxy coatings have been used extensively on power generation plant. However, very little is known regarding their long-term performance under different exposure conditions, as well as whether these coatings actually perform better than their solvent-borne counterparts. In addition, solvent free materials are generally used where outage periods are restricted and coatings need to be applied within a very short period. Though these materials have reportedly much shorter curing times than other conventional solvent-borne coatings, little is known regarding their limits with respect to maximum film thicknesses and being put into service while still being wet/partially uncured. The latter has become common practice at many power stations in the past two years or so. In addition, the application and curing methods of solvent free materials are different to that of solvent-borne materials, and may require equipment and application process changes. This paper covers the application and performance properties of solvent free coatings in comparison to solvent-borne materials primarily intended for immersion service. Numerous coatings were evaluated under immersed static and cyclic hydrostatic pressures. Other tests included short curing / early immersion tests, dry-to-touch and dry-through curing times, adhesion tests, surface tolerance tests, etc. The results show that the solvent free materials have clear benefits with respect to safety, health, environmental and long-term performance, but will be more difficult to apply compared to solvent-borne materials.

Jan 1, 2006

By Arthur L. Holloway, James C. Mugford

"The Underground Research Laboratory (URL) is located in southeastern Manitoba, in the Lac du Bonnet granite batholith of the Canadian Shield. It was constructed by Atomic Energy of Canada Limited (AECL) to conduct geotechnical research for the Canadian Nuclear Fuel Waste Management Program, assessing the concept of permanent disposal of nuclear fuel waste deep in plutonic rock.One of the primary objectives of the research program at the URL is to develop a nondestructive rock mass characterization method that can be used during siting, design and construction of a used fu el waste disposal vault. An experimental program was established to assess radar reflection profiling as a technique for fracture characterization in granite. The highly resistive, homogeneous nature of the Lac du Bonnet granite is ideal for the propagation of electromagnetic energy at the radar range of frequencies and water-filled fracture zones act as excellent reflectors because of their contrasting electrical properties.Radar reflection profiling was undertaken to characterize a major fracture zone located between 5 m and 10 m below Room 211 on the 240 m level of the URL. The profiling was done at a frequency of 120 MHz, on a 1m grid laid out on the bare rock floor of the room. Reflectors identified in the analog data were correlated between the profile lines, digitized, and a three-dimensional surf ace for each recognizable reflector was constructed. These surf aces were then compared with data obtained from the examination of numerous cores from adjacent boreholes intersecting the fracture zone. A very good correlation was found between the major radar reflectors and the most intensely fractured regions of the zone. Modelling studies also showed that a series of prominent shallow radar reflectors were caused by a borehole drilled close to Room 211."

Jan 1, 1990

By Open-Hearth Steel

I received a telegram yesterday from Mr. J. H. Nead saying that he regretted circumstances had come up which prevent his attending the meeting, but that arrangements have been made and Mr. T. S. Washburn, of Inland Steel, will act as the Co-Chairman in his stead. We are sorry, of course, that he cannot be here at this conference. We have, therefore, asked Mr. James J. Bowden, chief metallurgist of Republic Steel Corporation, Cleveland, to act as Chairman and Mr. Tom Washburn to act as Co-Chairman. I will turn the meeting over to these gentlemen at this time.

Jan 1, 1940

By F. L. Mentg

The utilization of acid leaching tailings was studied. It is obvious that the Fe in acid leaching tailings can be leached into solutions as Fe2+. In this paper, the influence of conditions, including the concentration of ferrous sulfate, pH, temperature and velocity of air flow was investigated. The optimum conditions for preparing seed crystal are as follows: the concentration of ferrous sulfate is 20 g/L; pH is 9.5~10; reaction temperature is 10~20?; velocity of air flow is 0.4m3/h. The optimum conditions for preparing iron oxide red are as follows: the concentration of ferrous sulfate is 5 g/L; reaction temperature is 80~85?; velocity of air flow is 0.13m3/h. At last, the product of iron oxide red could be prepared by ammonia method.

Jan 1, 2014