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By W. Tse, D. Wong

Dense medium separation (DMS) is one of several preconcentration methods used for early waste rejection from run of mine ores at relatively coarse particle sizes prior to additional milling and beneficiation. DMS has been used extensively in the coal, diamond and iron ore industries but lab scale and pilot test work has demonstrated successful separation and upgrading of other minerals such as lead, zinc, copper and lithium based ores using DMS. This paper reviews historical dense media systems, results from the pilot scale Condor DMS system as well as associated laboratory heavy liquid separation (HLS) test work.

Jan 1, 2014

By M. Girard, C. Farsangi, N. Singh

"Canadian Royalties Inc. owns and exploits the Nunavik Nickel Project: a copper and nickel deposit in Nunavik, Québec. The nickel and copper concentrates are filtered by plate and frame filter presses, and are transported 100km north to Deception Bay by truck. As the site is situated in the far north, extreme weather can be detrimental to production: roads can close for significant periods of time, resulting in the concentrator using all its storage capacity. During the winter of 2017, this accounted for over 100 hours of unplanned mill downtime. Different solutions to this problem were evaluated and the most economically viable combination of solutions was determined to be the use of concentrate storage containers and upgrading the plate size of the existing nickel filter press. By satisfying new, increased utility requirements, the cycle times would not change, but produce 30% more filter cake. Simulations were developed to determine the number of concentrate containers needed in conjunction with the upgraded press to eliminate unplanned downtime due to road closures and secure production through the winter. This paper summarises these simulations, the commissioning and start-up of the upgraded filter press, container loading procedures, and how this was put together to achieve a record 2018 winter season with a 90 percent reduction in downtime. The payback period of the project was 4 months. A specialised side-tipping trailer emptied the containers during the fall of 2018.INTRODUCTION The Nunavik Nickel Project is a nickel/copper mining project located in Nunavik, Québec. The nickel and copper concentrates are stored in stock tanks after thickening and are then filtered by plate and frame filter presses at the concentrator before being transported 100km to the shipping port at Deception Bay by trucks. The region is prone to periods of extreme weather during the winter, with winds that can reach +100km/hr and blizzards that severely limit visibility. The roads to Deception Bay are often affected by this weather, causing closures that last an average of 18hrs and as long as 72hrs. Additionally, there is a 15% chance that road closures occur within 24hrs of the last event. This has been an issue for the concentrator team since start-up in 2013, causing unplanned mill downtime every winter (Table 1) due to filling concentrate storage capacity during prolonged closures of the roads to Deception Bay."

Jan 1, 2019

By C. Jay Hodgson, P. J. MacGeehan

"The gold ore zones of the Campbell and Dickenson mines occur within a km-wide, 2 km-long zone of highly altered and anomalously fissile and deformed volcanic and subvolcanic intrusive rocks, cut by a series of mainly post-deformation mafic and quartz-feldspar porphyry felsic dykes.Three main periods of gold ore-forming hydrothermal activity are recognized. In the first, the mine rocks were extensively altered and gold and arsenic enriched; syn-volcanic auriferous veinlet and low-grade chemical sedimentary ores were deposited in what was a major discharge zone of a submarine hydrothermal system. The chemical sedimentary ores are closely associated spatially and temporally with domal rhyolitic extrusions. Because of its mechanical and chemical properties, this synvolcanic alteration zone became the locus of later deformation, and the site of the generation of auriferous hydrothermal solutions, perhaps by pressure solution processes at depth. These solutions deposited, synchronously with deformation and metamorphism, the second and most economically important type of ore zones in the mine: large foliation-parallel and foliation-oblique banded carbonate- 'chert' Rssure-filling veins.In the third and final mineralizing event, high-grade, pipeshaped zones of siliceous replacement-type mineralization, and quartz-arsenopyrite-gold veins, were superimposed on the previous mineralization types after most of the deformation, but before the emplacement of the late dykes. The source of heat and also possibly the fluids for the third mineralizing period may have been the dyke-forming igneous activity. The textures and mineralogy of the banded carbonate- 'chert' veins suggest a near-surface (<3 km) environment of deposition, but their relationship to the fabric of their host rocks indicates they were emplaced in an environment, presumably at considerable depth (5-10 km?), in which the rocks were undergoing intense penetrative deformation. This anomaly is unresolved."

Jan 1, 1982

By R. W. Smith, Z. Sadowski

The stabilities of finely divided mineral suspensions were determined as functions of pH and concentrations of polyethylene oxide, sodium ligninsulfonate, sodium dodecybulfate, and sodium oleate. In addition, the electrokinetic potentials of the minerals were determined under identical pH and additive concentration conditions. Flocculation or dispersion of the suspensions is discussed in terms of both the amount and manner of adsorption at the appropriate solid-liquid interface as it is influenced by additive concentration and pH.

Jan 1, 1986

By S R. Pecover

AustraliaÆs opal and sapphire mining industry has fallen from its peak in the 1980s and 1990s into a significant low today. This is not due to exhaustion of the resource, but instead an over-reliance of the Australian miner on achieving a fair price for the gemstone product from offshore middlemen dealers. Gemstone and geological research is also at a low as Federal higher education expenditure has fallen with research institutions relying increasingly on private funding in an environment of restricted autonomy and flexibility for researchers. What little remaining research skills the universities have is being bled into the private sector as a result of the mining boom and encouraged by lower than average academic salaries. Nevertheless, some highly innovative research has been taking place, often by self-funded individuals and retired academics simply with a desire to advance the understanding of the particular branch of science in which they are interested. New models for the formation of sapphire and opal are now beginning to be applied to the exploration for these gemstone commodities. This research, together with well thought out plans for managing the gemstone product through its value-adding steps to the jewellery retail level, has the potential to bring about a resurgence in the Australian gemstone industry.

Jan 1, 2008

By J. E. Dooley

Reference mass spectra and analytical correlations for 20 alkylcycloalkyl sulfides and two dicycloalkyl sulfides are presented &apos;to provide information that will facilitate the identification of sulfur compounds occurring in natural or synthetic mixtures. Reference spectra indicate relative intensities in addition to parent and base peak sensitivities. Analytical correlations establish the ionic species that reflect major fragmentation paths for the com-pounds studied. Specifically, the correlations show that base peaks are formed by several different processes: (1) Cleavage of the bond a to the ring, (2) fragmentation of the alkyl chain, and (3) fragmentation of the ring plus fragment contribution from the alkyl chain. Useful correlations for deter-mining alkyl chain length involve the CnH2+3S+ and CnH2n+1 + ions. CnH2n-2+ and CnH2n-1 S+ ions reveal the number of carbon atoms in the cyclic ring. Other important ionic species are also discussed.

Jan 1, 1970

By R. R. Sayers

Under compuision of the present urgency to implement the President's promise to make the United States the arsenal for the democracies there is a tendency to demand a relaxation of restrictions on hours of labor and to speed up all industrial processes. The pressure is the more insistent with growing realization of the importance of the time factor in the success- ful prosecution of the war effort and the lack of skilled workers due to (2) operation of the draft, lack of an apprentice system in industry, and loss of skill by workers unemployed for long periods during the depression. With "total" war such as it is today the probabilities are that everyone will be required to exert greater effort (in many instances in activities to which they are unaccustomed) for longer periods than ever before has been necessary. The question arises, "What will be the aftereffects as well as the immediate effects on health, safety, and efficiency?" A review of the literature leaves the impression that this question has not been an- swered completely, especially as regards the ultimate effects. Mechanization, speeding up of industrial processes, mass produc- tion, and the small industrial concerns present many problems to indus- trial medicine. Does the tendency to expect the worker to produce at full speed all the time he is on the job decrease the effectiveness of the shorter working hours and cause undue fatigue, loss of efficiency, and increased accident proneness? The answer is important as this condition is likely to be intensified by the exigencies of the present emergency. According to Viteles (1)3, The increased tension under such conditions of work appears to offset the savings in muscular force made pos- sible by the machine. The tension, the speed, the subject- tion to specialization of work and a rhythm uncontrolled by the individual promote fatigue, characterized by a "decrease in the power to work, a decrease in pleasure taken in work, and a decrease in the enjoyment of the hours spent away from work."' The crowding of workers in temporary structures without proper provision for comfort and health may add greatly to the general fatigue factors already present in many industrial establishments. In 1932 Lockhart (2) stated that the production and maintenance of a healthy, satisfied industrial population is the most urgent necessity, involving problems so serious as to constitute a national task too great economically to be relegated to industrial concerns. If this was true in 1932, it must be doubly so today.

Jun 1, 1942

"The business importance of water for mining companies is unequivocal as it may affect several aspects of mining projects ranging from the life-and-death license to operate to the imperative economic viability. It is thus no wonder that nearly all mining companies acknowledge water-related risks, issues and opportunities in their respective sustainability report. Somehow, this procedure has fostered the idea that water frugality could be the sustainable solution to several water-related issues. The regular exercise of water accounting should then follow as a key strategic requirement. Water accounting is defined as the application of a consistent and structured approach to identifying, measuring, recording and reporting information about water. However, several factors discussed herein have led to the fact that some water accounts are still produced using means (hardware and software) which undermatch the value actually associated with water. The resulting fuzziness about water usage could result in missed opportunities, suboptimal operations or even lead to environmental law violations. This paper subscribes to the distinctive perspective that, once underlying concepts and practical definitions have been standardized under a supported framework, such as the openly available Water Accounting Framework (WAF) published by the Minerals Council of Australia, most of the remaining water accounting issues may be boiled down to accuracy issues and, ultimately, to how much accuracy is valued by the stakeholders. Using the latest WAF document as a baseline for best practices of water accounting and, borrowing concepts from the fields of sensor network design in the process industries and best practices of metal accounting, this paper reviews some essential accuracy issues to be considered when designing or analyzing water accounting systems in mineral processing. The current paper also includes some elements for a promising attempt to include the value of information paradigm inside the water accounting best practices."

Jan 1, 2014

By Walter Murphy

For a number of years the Bureau of Mines has been studying the properties of crude petroleums produced in the United States and the Western Hemisphere. A number of reports have been published giving the analyses of crudes from the different fields and regions as made by the Bureau of Mines Hempel method of analysis.4 Several of these reports include analyses of crude oils from the Rocky Mountain region.5/ The search for new fields and new producing horizons in old fields in the Rocky Mountain region has been quite intensive during the last few years, and a number of discoveries have been made.

Jan 1, 1937

By Johannes Käppeler, Alexander Weh, Harald Giese, Klaas van der Wielen

"High voltage breakage is a novel comminution technology that shows considerable potential for various applications in mineral processing and recycling. It relies on highly energetic electrical pulses to induce electrical explosions in rocks, causing the formation of plasma channels and powerful shockwaves that result in fracturing and fragmentation of particles. There has been considerable interest in this technology for its ability to weaken rocks and preferentially liberate target minerals, as previously demonstrated by other authors. Weakening has the potential to significantly reduce energy consumption during comminution, or alternatively, increase throughput of a circuit. Better liberation may yield an improved concentrate grade and/or recovery, reduce fines losses to tailings or increase the grind size required for liberation, thereby also reducing energy requirements. This review aims to increase general awareness of this technology, and promote further research into it by providing a general summary of the theory underlying high voltage breakage, as well as the envisaged applications of this novel technology. A brief history of the technology is presented before progressing onto the physics underlying the electrical and geomechanical aspects of high voltage breakage. Key results regarding weakening and liberation are discussed, and some mention is made of current challenges and planned developments to increase the throughput of high voltage breakage units to the level where it can be integrated into new and existing processing circuits."

Jan 1, 2014

By M Norbert, C Bennett

The Legacy Way Tunnel was constructed from Toowong to Kelvin Grove in Brisbane, and is the first large-scale underground excavation in the Bunya Phyllite in Brisbane. The Legacy Way Tunnel is 4.3 km in length, comprising two mainline tunnels excavated by a tunnel boring machine (TBM) with 46 connecting passages excavated between the mainline tunnels for egress provision and services. The Legacy Way Tunnel passes through two geological formations, the Bunya Phyllite and the Neranleigh Fernvale Beds. The Bunya Phyllite is the dominant formation of the Legacy Way Tunnel, extending for three quarters of the tunnel prior to intersecting the Normanby Fault Zone (NFZ) and the Neranleigh Fernvale Beds. The NFZ forms the contact between the two formations as part of the Brisbane Metamorphics, which underlies the majority of Brisbane City. The development of the geological model and the understanding of the ground’s reaction to tunnelling was an iterative process. The tender phase investigation data has been supplemented with additional design phase investigation boreholes, geophysics and walk overs. Aerial photograph interpretation coupled with borehole data allowed the development of the domains along the length of the tunnel. Early excavations for the spoil conveyor tunnel and borehole data from subsurface instrumentation installation provided the first construction phase data followed by the commencement of tunnel boring machine (TBM) excavation. Routine cutterhead inspections coupled with ongoing reviews of the predicted geology resulted in clear response triggers to selection of segment types while detailed inspections in passage locations provide the initial classifications for segment removals.CITATION:Bennett, C and Norbert, M, 2014. Tunnelling within the Bunya Phyllite of Legacy Way, Brisbane, Queensland, in Proceedings 15th Australasian Tunnelling Conference 2014 , pp 131–140 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Sep 17, 2014

By Alton B. Cook

A material balance equation was derived for calculating (1) the initial oil volume and (2) the relationship of average reservoir pressure to net gas in storage in reservoirs used for natural gas storage operations. The equation is also applicable to secondary-recovery operations where reservoirs are completely repressured and gas cycled. Using this equation minimized two probable sources of appreciable error in conventional material balance calculations: inaccurate measuring of and accounting for produced gas, and differences between true reservoir pressure and average reservoir pressures as derived from bottom-hole pressure measurements. A new procedure is presented for calculating water encroachment. By solving the conventional material balance equation and the derived equation for gas storage simultaneously, the values for initial oil in place and net water encroachment can both be determined.

Jan 1, 1966

By Alexander Schultz Rizek

O trabalho que será apresentado irá descrever o projeto realizado de atualização tecnológica do sistema de controle com controladores Automax instalado em um laminador de fio máquina de dois veios, a Acerías Paz del Río, da Votorantim Siderurgia na Colômbia. Este projeto consistiu na substituição do antigo sistema de controle com PLC’s Automax do laminador fio máquina de dois veios, mantendo-se parte do sistema antigo Automax convivendo com o novo sistema Contollogix. O novo PLC instalado para o controle do laminador foi o Rockwell ControlLogix, através do qual foi desenvolvido o controle principal do laminador, como: cascata de velocidade utilizando o fator R, que poderia ser ajustado do IHM (antes os ajustes eram feitos diretamente no rpm dos motores), controle de laços, controle das mesas de laço, as primeiras da Russula, produzidas e programadas em companhia com a Russula Itália exclusivamente para esse projeto, controle de tração, ciclos de posicionamentos manuais e automáticos, intertravamentos, etc.

Jul 30, 2018

By Árpád B. Palotás, Adel F. Sarofim, John B. Vander Sande, Lenore Rainey Christian, J. Feldermann

"Interest in the fine structure of soots and carbon blacks is motivated by a variety of possible applications. The structure provides information on the origins of the particles and on their adsorptive and reactive properties. This paper describes a method for quantification of the structure of soots and carbon blacks based on direct electron microscopic observation followed by image analysis of these materials. High-resolution transmission electron microscopy (HRTEM) provides a very detailed observation of particle structure. The differences in soot structure, because of its complexity, may not be easily quantifiable with the human eye; therefore, high-level computer software has been used to manipulate HRTEM images. This technique involves the application of fast Fourier transforms (FFT) to single particles and the measurement of characteristic parameters such as interplanar spacings and crystallite sizes from these particles. The methodology and application of this characterization technique are presented here. Results are shown for dif¬ferent samples obtained from soot and carbon black particles selected to illustrate the capabilities of the methodology. Quantitative information can be obtained on structural characteristics, e.g., interplanar spacing, circularity, orientation, elongation, and length distribution of lattice fringes, as well as on the fractional coverage of the extracted pattern. c 1996 Wiley-Liss, Inc.This paper presents a combination of techniques for recognizing and classifying different carbonaceous materials, using their structural morphology. A new method to assess and quantify the parameters which define such structures is proposed and discussed. The technique is based on the use of HRTEM (high-resolution transmission electron microscopy) and computational image analysis.It is well-known that carbonaceous materials like graphite, soots, coals, cokes, chars, etc. possess characteristic structural appearances which can vary from mostly random or amorphous to a perfectly ordered graphitic crystalline structure (Buseck and Bo-Jun, 1985; Buseck et al., 1987). The carbon structure has been variously described as turbostratic (Oberlin, 1989) or as crumpled sheets (Rouzaud et al., 1991) to indicate that parallel layering, reminiscent of graphite, is observed over dimensions of nanometers, but that these planes or crystallites show disorder over larger scales. The degree of order of such structures is strongly dependent on the thermal treatment of the material as well as on the composition of the source of the carbonaceous material. The value of the electron microscope in studying the morphology of such materials has been well-established, and abundant information is available (Ishiguro et al., 1991; Lahaye and Prado, 1978; Buseck, 1992).The use of HRTEM has brought further insight into this matter. Qualitative assessment of the structural order of such materials has been attempted over a long period of time in order to differentiate between various sources or treatments. There is, to date, no successful method available for quantifying the structural characteristics of various carbonaceous materials. This paper presents a technique which is able to recognize dif-ferent materials and to quantify the structural parameters of those materials using HRTEM and computational image analysis, including pattern recognition techniques.In the case of perfectly ordered graphitic crystals, electron diffraction is widely used for obtaining details on structure. Analysis of diffraction patterns can reveal parameters such as interplanar spacing, d002, crystallite size along the c-axis, Lc, crystal size in the plane of the layers, L., mean number of crystallites, Nc, etc.Complicated electron microscopy methods such as defocusing, tilted illumination, axial illumination, etc., often have to be used in order to characterize complex materials such as randomly oriented crystals in soots and carbons. Obtaining the right fo"

Jan 1, 1998

By E. Parthe, J. P. Pemsler

TWO references can be found in the literature concerning the ternary system uranium-tantalum -carbon. C. H. Schramm, P. Gordon, and A. R. Kaufmam reported in this Journal1 on the existence of the ternary carbide "UTa10C4." They also report a second face-centered-cubic carbide phase in the system U-Ta-C, which they denote as "white" phase. The publication includes a reproduction of a Debye-Scherrer powder photograph of "UTa10C4" and a list of the sin2 0 values of this compound. H. Nowotny, R. Kieffer, F. Benesovsky, and E. Laube2 report the complete solid solubility between TaC and UC with a B1 structure. Since the ternary phase "UTa10C4" lies very close to the binary system Ta-C, and the established phase Ta2C with a C27 structure had not been mentioned by Schramm et al., it was thought worthwhile to compare the patterns of "UTa10C4" with Ta2C. The strong lines of the given pattern were indexed on a hexagonal unit cell with the approximate cell parameters a = 3.09A and c = 4.93A. These are the values reported for Ta2C in the literature.3 The correspondence between reported and calculated sin2 8 values may be studied in columns 4 and 5 of Table I. The agreement is fair, but there remain weak lines which cannot be assigned to the hexagonal unit cell. The extinctions correspond to those of Ta2C, but a comparison of the calculated and observed intensities of the Ta2C lines (columns 2 and 3) with those of the corresponding lines of "UTa10C4" (column 6) show occasional deviations. To clarify this situation, four new samples were prepared. The compositions of these samples were chosen in such a way as to observe any existing ternary phase in the system TaC-UC-U-Ta. The samples were arc melted in an inert atmosphere and annealed at 1100°C for 36 to 72 hr. Compositions of the samples determined by chemical analysis are given along with the results of X-ray investigations in Table 11. The following conclusions may be drawn from these data: a) No ternary compounds occur in the section TaC-UC-U-Ta of the ternary system Ta-U-C. The "white" phase reported by Schramm et al. corresponds to a solid solution between TaC and UC. Only one three-phase field exists: C27-B1-A2. (Both tantalum and ? uranium have body-centered-cubic A2 structures.) The a uranium observed in sample 4 transformed from the high-temperature ? phase on cooling. b) The phase Ta2C with a C27 structure extends into the ternary system. "UTa10C4" is, therefore, a uranium-enriched Ta2C. Good agreement is ob-

Jan 1, 1960

By R. B. Anderson

SULFUR poisoning of iron catalysts in the Fischer-Tropsch synthesis was investigated at the Bureau of Mines, because synthesis gas produced from coal contains sulfur compounds. Tests of two typical iron catalysts with synthesis gas containing known concentrations of H2S were made to determine catalyst life as a function of sulfur concentration to ascertain the type of gas purification required. Fixed beds of activated steel turnings and a fused iron oxide catalyst were investigated in sulfur poisoning tests at 21.4 atmospheres with IH2+100 gas containing 6.9, 23, or 69 mg S as H2S per cubic meter (0.3, 1.0, and 3.0 gr per 100 cu. ft.). In tests of reduced catalysts at constant temperatures, more than 80 percent of the activity was lost when 0.5 mg S/g Fe was introduced. Poisoning of nitrided or carbided fused iron oxide catalysts to a given extent required more than twice as much sulfur than for the corresponding reduced catalyst. When the synthesis temperature was increased to compensate for loss in activity, tests of the fused iron oxide catalysts at constant productivity could be continued for 19 to 98 days. The tests were terminated by clogging of the reactor, presumably caused by carbon deposition. One objective of the present work was to determine if synthesis gas, purified by the Bureau of Mines&apos; hot-potassium carbonate process for removing H2S, OOS, and CO2, is suitable for synthesis on iron catalysts. The sulfur content of the gas purified by tills process is in the range of concentrations used in the present work. In constant-productivity tests of nitrided fused iron oxide catalysts with synthesis gas containing 6.9 mg S/m3, catalyst lives are nearly long enough for serious consideration of tills mode of operation. However, factors relating to selectivity and stability of the catalyst indicate that this type of operation is impractical for a commercial process. On this basis additional gas purification, such as iron oxide boxes following a hot potassium carbonate scrubber, is desirable.

Jan 1, 1965

By G. Duncan

Distinct trends in grinding mill technology have emerged in recent years. In an effort to optimize overall mill performance for the needs of the End User, broad measures of logistical speed, process flexibility, operational risk, and overall costs now exert greater influence on the specification of grinding equipment. As a result, innovative alternatives to conventional grinding mill structures, supports, drives, feed, and discharge configurations are now being offered and selected with greater frequency. This paper investigates these trends in grinding mill technology, utilizing optimization and decision-theory techniques. In particular, the paper considers how specific advances in process design, product engineering, manufacturing techniques, and mining operations continue to relax technological constraints, enabling further mill innovation. In this context, a methodology is presented, illustrating how proper selection and specification of grinding mill components and configuration can target an optimization of the four End-User performance measures listed above..

Jan 1, 1999

By Frank J. Wiebelt, Spangler Ricker

"INTRODUCTION Bauxite, in Appalachian Alabama, occurs in the Rock Run and Goshen Valley districts in Cherokee County; in Nences Creek Valley near Jacksonville; near Anniston in Calhoun County; north of Fort Payne in DeKalb County; near Ashville in St. Clair County; and near Talladega in Talladega County.In February 1942, Preston E. Cloud, Jr., assistant geologist, Federal Geological Survey, began a study of these bauxite deposits and the geology relating thereto.The Bureau of Mines established field headquarters at Piedmont, Calhoun County, in July 1942. Mineral agreements covering a total of 11,097 acres were executed with 15 landowners in the Rock Run district; 38 in the Goshen Valley district, covering 7,575.5 acres; and 3 in the Nances Creek Valley district, covering 988.5 acres. Drilling was done on.the properties of 9 land¬owners in the Rock Run district, and on the property of 1 landowner each in the Goshen Valley and the Nances Creek districts. Drilling began October 26, 1942, and ceased on May 17, 1943.Power drilling was supplemented by a labor crew that drilled hand-auger holes in shallow deposits and sampled .old shafts, mines, and mine dumps.In all, 222 holes for a total of 13,250 feet were drilled. Of these toles, 88 penetrated bauxite but too low in grade to constitute ore."

Mar 1, 1948

By M. Bhartia

India is the 5th largest producer of steel in the world and is slated to produce more than 180 Mt by 2020. Expectedly about 50 % of this would be through the Blast furnace route and the rest through Sponge iron / DRI route. Considering that there will not be any major change in iron making technology by that time, the Blast operation would require lump ore (10-40mm) with around 64% Fe grade and sinter fines (<10mm) with 60% Fe (min) as its feed. DRI process would need calibrated ore of size 5-18 mm as the most suitable size of feed. It is also expected that of the total requirement of ore for the DRI route a significant part would be DRI pellets. In India, there is considerable debate going on regarding the technology to be adopted for the processing of iron ore and there is a lack of clear consensus. The above scenario indicates that the processing requirement of iron ore in the country would involve both washing technology as well as beneficiation technology. CDE Asia Ltd is in the forefront of iron ore processing in the country and the experience gained by the company over the last few years of functioning has led the company to believe that route to be adopted depends on the end product requirement and the starting grade of the feed. Keeping in mind the nature of the feed required for the Blast furnace & DRI operation; it is obvious that good washing technology would be highly beneficial to the iron ore industry. Depending on the grade of ore available the limits of washing will be decided and equipment for lump ore beneficiation such as jigs could be incorporated into the washing circuit. Scrubbing of ore either before washing or selectively scrubbing the lumps could be necessary. Very low grade ore and jig rejects would be required to be totally ground and beneficiated for the production of pellet feed in order to utilize the iron ore resources entirely. Another source of ore for pelletisation would be slimes generated from the washing process as well as the huge quantities already available in the tailings dams in the operating mines. Deslimimg and magnetic route of beneficiation could release at 30-40% of the Fe locked up in these tailings ponds/dams. The paper describes the concept with examples from operating plants and proposes how the adoption could be engineered through test work and proper plan of integration. Keywords: washing, beneficiation, iron ore, lumps, sinter fines, pellets, jigs, screens, evowash, nanowash, thickeners, log washers, drum scrubbers

Sep 1, 2012

By C. M. Keenan

During the 7-1/2 years (January 1945-June 1952), immediately preceding enactment of the Federal Coal Mine Safety Act, 26 major disasters3/ in the coal mines of the United States caused the deaths of 491 persons. In the next 7-1/2 years under the act (July 1952-December 1959), only 12 major disasters occurred. The total killed was 148. This improvement is commendable. However, the continuing frequency of minor fires and gas and/or dust ignitions in the Nation&apos;s coal mines, many of which could have been of major consequence, are cause for serious concern to the coal-mining industry and those affiliated agencies engaged in promoting safety in the industry. The data presented in this report have been prepared to make available to the coal-mining industry and related groups an overall perspective of the disaster potential from mine fires and gas and/or dust ignitions in coal mines after 7-1/2 years under the Federal Coal Mine Safety Act. This act, effective July 16, 1952, which amended the original Federal coal-mine investigative act of May 1941, provides under Title II certain enforcible mine-safety provisions designed to prevent major disasters caused by explosions, fires, inundations, and man-trip and man-hoist accidents in coal mines that employ 15 or more individuals underground.

Jan 1, 1960