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By Yuanbo Zhang

Keywords: Complex Iron Ores, Roasting, Tin, Zinc, Pellets, Comprehensive Recovery. The complex iron ores containing tin, zinc are typical refractory ores. Large reserves of the ores are found in China and have not been utilized efficiently so far. A new process of tin and zinc recovery and pellet preparation from iron concentrate containing tin and zinc by controlled atmosphere roasting is developed in this investigation. The results of 2573 N/P compression strength of product pellets, the 91.49% and 82.22% volatilization of tin and zinc respectively, are achieved for a concentrate containing 0.39% tin and 0.28% zinc. The strength and chemical compositions of the pellets meet the requirement of blast furnace ironmaking. Volatilization mechanism of tin and zinc are investigated. Thermodynamic study shows that the reduction balance curves of SnO2(s) and SnO(g) are proximate in the presence of carbon, and the standard formation free enthalpy of FeO and SnO2 is also approachable. Therefore, it is difficult to realize the complete volatilization of tin in the form of SnO(g) by selective reduction. But SnO2(s) and SnO(g) will form SnCl4(g) or SnCl2(g) in the presence of chlorides and can be easily volatilized from the ores.

Jan 1, 2005

By Sam Bang Jr, Rodney Burke

As mining progresses in the West, the depth of material has increased, making highwall stability a major factor in safety and production. The Jim Bridger Coal Mine’has made highwall stability a priority, concentrating on safety as well as increasing and improving production. Overburden depths are increasing dramatically; the geological environment consists of medium to sot? material, faulting, water, and current pit alignment not favorable to joint planes. Angle drilling the presplit at 20 degrees became necessaryas vertical presplit drilling produced wall failures.

Jan 1, 1998

A calibration of the Frantz isodynamic magnetic separator relates the current in the electromagnet and the transverse slope of the chute to the specific susceptibility at which separation is being effected. In addition to providing a rapid measure of the specific susceptibility of minerals and composite grains, the calibration provides a guide to operation of the Frantz isodynamic separator for mineral separation, and to the nature of composite grains. The most sensitive magnetic separation is obtained by using the highest practicable current and transverse slope, and the lowest practicable longitudinal slope.INTRODUCTIONProbably all minerals have a magnetic susceptibility measurable by sensitive techniques. However, magnetic separation between minerals which have low but different specific susceptibilities, and which for many purposes are considered essentially non-magnetic, has only become practicable with the development of the Frantz isodynamic separator.The construction and principle of this highly sensitive separator has been described by S. G. Frantz as an appendix to a description by 'Gaudin and Spedden (1943) of its application to the separation of sulphides constituting mill products.Various publications (e.g. Hess, 1949, Hutton, 1952) refer to its use in separating the mineral constituents of rocks, ores, and unconsolidated sands.As used in this study the Frantz isodynamic separator consists of a vibrating chute mounted centrally between the pole pieces of an electromagnet (Fig. 1). This unit may be inclined in any direction by the universal mounting, and the electromagnet current is continuously adjustable from 0 to 1·5 amperes.

Jan 1, 1957

By R. L. Caldwell, E. E. Glenn, L. J. Norton, A. J. D. Straus, S. V. Holcomb, J. Zemanek

A new and unique logging tool, called the Borehole Televiewer (BHTV), has been developed to inspect boreholes and to evaluate formations. Even though geologists and engineers have had only about 3 years' experience with the BHTV, the thinking of many of them has been radically influenced by the fascinating and revealing "log-picture" recorded with the tool. The BHTV fills a need for a logging tool that can produce a direct and descriptive record of the physical properties of the borehole environment. Although primarily developed to evaluate fractured reservoirs, the BHTV has been used successfully to solve a variety of problems related to formation evaluation and borehole inspection. Geologists and petroleum engineers have been confounded for many years by the problems of locating and evaluating fractures. Interpretation of the usual resistivity, acoustic or radioactivity logs, as well as the analysis of cores, for evaluation of fractured reservoirs is extremely difficult and often not definitive. This is understandable since analysis of cores from fractured formations has reported variously: (a) low porosity, (b) no effective permeability, (c) lack of any matrix oil saturation and (d) oil stains on fracture planes as the only indications of potential production.14 In recent years acoustic amplitude logs have been introduced and used with varying degrees of success to locate fractures.8'9'11"13 Conventional amplitude logs at best give only qualitative answers where quantitative ones are desired. The logs reveal nothing of the orientation of the fractures. In addition to these logs, various types of cameras, television, and rubber impression packers have been used for borehole inspection. (See Appendix.) The BHTV logging tool supplies both the quantitative and the orientation answers about fractures. The borehole can be filled with any homogeneous, gas-free liquid such as fresh water, saturated brine, crude oil or drilling muds. This tool takes an "acoustic picture" of the borehole wall. The resulting log is a representation of the borehole wall as if it were split vertically and laid flat. The log is oriented with respect to magnetic north. Any physical changes in the borehole wall are seen as changes in picture intensity. In this way, fractures, deformation or pits are reflected on the log. Tool Description The fundamental parts of the BHTV are shown in Fig. 1. A piezoelectric transducer probes the borehole wall with bursts of acoustic energy. A flux-gate magnetometer senses the earth's magnetic field and provides the means for determining the orientation of the log. A motor rotates the transducer and mag-

Jan 1, 1970

Since the ecrly 1970's several factcrs have changed. In the East the larger tracts of coal mined with large eauipment are being dePleted, The cost of moving the larger equipment from small tract to small tract becomes eccnomicallv unattractive, Conseauently, the tracts are being mined with smal!er draglines or with loader/truck haulage combination, This has resulted in a major increase in the cost of moving a cubic yard of overburden,

Jan 1, 1989

By S. Roy

Soft laminated iron ore (SLO) having a higher hematite content and Martite goethite iron ore (MGO) having a higher goethite content were subjected to detailed characterization and beneficiation. The present research was designed to investigate if these abundant, low-grade ores can be enriched adequately using standard industry techniques. No significant enrichment of the ores using jigging operation on the coarse (-3,200 +595 mm) size fraction could be achieved. Good liberation was only attained in the 150 to 300 mm particle size range in both cases. Desliming enriches the ground ores significantly. The effect of the feed size on the separation efficiencies of the ground ores were studied using flowing-film concentration on a Wilfley table. Better enrichment is obtained in the case of 150-mm sized feed by tabling. The grade of SLO is improved from 56.14% to 66.51% Fe, while the Fe content of MGO is enriched from 55.16% to 65.83%. Substantial rejection of alumina and silica is also achieved. Due to the friable nature of MGO and the higher goethite content in it, the loss of Fe in the form of ultrafines is greater in this case compared to that of SLO.

Jan 1, 2009

By L. Xinghua

Limonite is a general term for a group of amorphous iron oxide and iron hydroxide materials. It is considered as one of the very refractory iron ore types due to its wide variation in chemical composition, iron content, moisture content and easily sliming in the course of comminution. Iron grade of test sample is 25.48%, the iron minerals are mainly limonite; and the gangue minerals consist of quartz and feldspar in majority, secondarily silicate minerals. In this test work, high intensity magnetic separation (HIMS)-cationic reverse flotation and magnetic roasting-low intensity magnetic separation (LIMS) tests were conducted on limonite ore. The test results show that the concentrate with iron grade of 50.97% and recovery of 68.50% can be obtained by HIMS-cationic reverse flotation technique; while using magnetic roasting-LIMS technique, the better concentrate indexes of iron grade of 60.36% and recovery of 89.71% are achieved, and the iron grade of tailing is only 4.42%. Therefore, the magnetic roasting-LIMS technique is a better suitable method for beneficiation of low-grade limonite ore. Keywords: Low-grade limonite; Mineralogy; HIMS; Cationic reverse flotation; Magnetic roasting; LIMS

Feb 27, 2013

In 1962, minerals beneficiation showed definite signs of coming out of the doldrums into which it has drifted after the uranium boom. Demand by steelmakers for high-grade iron pellets has created the need for concentrating plants to upgrade specular hematite by spiral concentration or flotation and magnetites by magnetic means and flotation. According to a paper given at the AMC annual meeting by C. S. Arms of Pickands Mather, "the shipment of pellets, started in the mid-1950's, has increased to 17.6 million tons in 1961 from North American operations. Many plants already underway will raise this production to about 42 million tons by 1965. This will be a very sizeable percentage of the total iron ore production contemplated by that date." Iron ore concentration methods are gradually raising the assay of pellets into the 65 to 69% Fe range and lowering silica to the 4 to 7% range. Quebec Cartier's Lac Jeannine concentrator went into operation in late 1961 and all grinding units were running by 1962. The Iron Ore Co. of Canada's new Carol Lake plant was started in mid-1962.

Jan 2, 1963

By Donald Christofferson

This report documents the program conducted to demonstrate the application of a flywheel-powered propulsion system to underground mining shuttle cars. Such application can replace the present electrical trailing cable common to most shuttle cars and thereby eliminate those safety hazards, maintenance problems, and haulage route limitations inherent in the trailing cable. Described are the activities undertaken to specify and design a flywheel of optimum size, shape, and material; to identify the best concepts of input and output systems; and to achieve installation of the power package into a shuttle car. The resultant Flywheel-Powered Shuttle Car is an FMC Model 6L shuttle car, 6-ton capacity, 20-ton gross vehicle weight, powered by a flywheel system with 4.5-kilowatt-hour usable energy. The completed vehicle was delivered to the Bureau of Mines in Bruceton, Pennsylvania, for testing and evaluation.

Jan 1, 1986

By Jaime Rebolledo, Carlos Toro

Muchas situaciones pueden ocurrir durante el cambio de turno en una operación minera y relación a la información que se genera, como por ejemplo: i) Silos de información, ii) uso de herramientas no estándar para compartir eventos de seguridad, iii) Necesidad de movilizarse a un centro de mando para declarar un evento peligroso detectado durante el cambio de turno y iii) la existencia Información dispersa El presente artículo propone la creación de una herramienta basada en Gemelos Digitales que tiene por foco, el apoyo a la actividad de cambio de turno. Los Gemelos Digitales poseen una característica innata de poder ser aglutinadores de información y por ello representan una excelente oportunidad de implementación.

Sep 29, 2023

By Bruce D. Hansen

For many years, Newmont has focused on improving its operations. After the merger between Newmont and Santa Fe Pacific Gold, Newmont created synergies of more than $50 million a year in Nevada. This was done primarily through optimal ore movements and consolidation of various functions. During the current period of low gold and copper prices, Newmont has refocused its efforts on efficient operations worldwide. At its mine facilities in Nevada, Newmont has used a combination of several strategies to decrease the costs of operations and to increase profitability. These include computer technology, optimal use of infrastructures, procurement strategies, functional consolidation, enhanced mine planning and several available metallurgical processing options.

Jan 1, 1999

Detailed mineralogical investigation of a tailing sample from the Juno plant circuit at Tennant Creek was carried out to determine the nature of the unrecovered bismuth and whether any possibility existed for improving bismuth recovery. The investigation showed that the Ibismuth was present in a complex mixture of Bi-Pb-Ou-Se-S minerals (termed "bismuthinite"), of which about 74 per cent was locked (mainly with magnetite) and 26 per cent was liberated (18 per cent in the minus 7 µm slime). The results suggested that attention should be directed to both finer grinding and improved flotation of slime "bismuthinite", and testwork carried out by Peko Mines N.L. on the basis of these recommendations led to a significant improvement in bismuth recovery.Detailed mineralogical investigation of two Juno concentrates was carried out to determine the nature of the selenium present and whether any possibility existed for improving the selenium grade. The investigation indicated that virtqally all the bismuth, selenium, and lead was present in "bismuthinite", which showed a composition range of 32-82 per cent Bi, 0-42 per cent Pb, 0-24 per cent Se, and 5-18 per cent S. Differences in the Bi/Se ratios of the two concentrates could be attributed to different average Bi/Se ratios of the constituent "bismuthinite", and the relatively low selenium grade of the "bismuthinite" precluded the possibility of obtaining a high grade selenium concentrate with high selenium recovery.However, differential flotation and/or low intensity magnetic separation to remove chakopyrite, and magnetite, the main diluents of the concentrate, could be expected to upgrade the selenium content byup to 80 per cent (relative) and .festwork carried out by Peko Mines N.L. on the basis of the recommendations of the mineralogical investigation confirmed that depression of chalcopyrite in the flotation circuit could produce significantly improved selenium grades.These investigations illustrate the application of mineralogy to the practical problems of improving plant performance. Mineralogy has an important role to play in providing quantitative data on which the metallurgist can evaluate plant performance and base a programme of metallurgical testwork, and early mineralogical investigation of feeds, concentrates, middlings, and tailings can lead to the avoidance of much abortive and expensive metallurgical testwork.

Jan 1, 1974

By E. F. Schnitzer

During 1996 and 1997, Oregon experienced flooding on a scale not seen in many years. Some gravel pits located near rivers experienced erosion. In several cases, breaches occurred between the gravel pit and the river. Initial evaluation of several sites that experienced these breaches showed that impacts to the river system were complex and varied significantly from site to site. The impacts to the adjacent river system may be viewed as positive and negative. Several flood-plain-mining sites in Oregon located in areas of historic river flow reverted to active riverbeds. In many cases, state and federal fisheries biologists and university researchers saw the resulting increase in channel complexity and habitat as favorable. The Oregon Department of Geology and Mineral Industries —Mined Land Reclamation Program (DOGAMI-MLR) is studying the effects to the off-channel areas that resulted from the 1996 floods. More data is needed to make sound flood-plain decisions regarding mining.

Jan 1, 1999

The Detachment of Coarse, Composite Particles from Bubbles

Sep 13, 2010

By Oliver C. Fursman

These investigations were conducted to determine conditions for recovery of nickel and copper from Funter Bay, Alaska, sulfide ore and recovery of nickel from nickel-silicate ore, Nickel Mountain, Riddle, Oreg. Samples of Funter Bay cupriferous and nickeliferous pyrrhotite ore, were treated by beneficiation, roasting, electric smelting of roasted are for matte production, chlorination, leaching, and sulfatizing roasting with subsequent leaching. Funter Bay and Nickel Mountain ores were smelted together to produce matte. Total sulfide flotation, followed by magnetic separation of the tailings to recover entrained nickel-bearing pyrrhotite, resulted in the highest nickel recovery in beneficiation tests on Funter Bay are. Overall beneficiation resulted in recovery of 98.5 percent of the copper and 95.4 percent of the nickel in the concentrate that contained 3.5 percent copper and 1.7 percent nickel.

Jan 1, 1962

By R. R. Oder, R. E. Jamison, E. D. Brandner

This paper presents preliminary test results obtained with a 0.38 kg/s (3000 lb-hr) beta prototype MagMill™. In processing Upper Freeport coal the beta prototype recovered 82% of the weight of the feed and 91% of the heat content while reducing the potential emissions of sulfur, kgSO2/GJ(lbSO2/MBtu), by 61%. Pyritic sulfur in the MagMill™ product was reduced by 78% compared to that in the feed. For all runs, the mill product was controlled between 70 to 80% finer than 74 µ particle size. Recoveries of mercury, arsenic, and selenium ranged from 35 to 45% of that in the feed. Power draw was reduced by 26% and mill throughput was increased by 9% compared to the pulverizer operating with no magnetic separator attached.

Jan 1, 2000

By Derek J. Penrice

The Caltrain Downtown Extension (DTX) project will extend commuter and future statewide high-speed rail service into the Transbay Transit Center, which will be located in the business district in downtown San Francisco. The DTX project includes 1.5 miles of underground construction, comprising complex sections of mined and cut-and-cover tunnel. As part of the DTX preliminary engineering process, development of appropriate contracting practices, including contract packaging, procurement methods and contract terms for the underground construction, has been initiated. This paper provides a summary of the evaluations undertaken, preliminary conclusions reached, and proposed next steps to promote industry interest and maximize bid competition.

By Ruy L. Rodrigues

Vale is in the early stages of commissioning its Onça Puma nickel operations. The project is meant for the production of 58,000 tpa of nickel contained in ferro-nickel, substantially contributing to the company?s vision to achieve world leadership in the nickel business. Mineral resources will be exploited from the homonymous deposits in the Midwest of state of Para, Brazil ? some 100 km southwestwards from the company?s Carajás iron ore properties. Resources as of 83 Mt at 1.73 % Ni will sustain a mine life of approximately 40 years. The property was acquired in late 2005 and Vale has since extended the engineering studies and proceeded with the implementation. Nickel will be mined from saprolitic ore at a rate of approximately 10 Mtpa (ore plus waste) in early years ? ramping up to some 15 Mtpa 7 years later ?, to feed the plant at a rate of 2.5 Mtpa. The process uses conventional RKEF (Rotary Kiln Electric Furnace) pyrometalurgical route whereby the ore is homogenized, calcined in rotary kilns, melted in electric furnaces and further refined to ferro-nickel. The plant has been designed and constructed applying the latest available technology, aligned with Vale?s vison to exceed the highest existing standards for environmental control, health and safety and productivity in the industry. Total investments in these operations are anticipated to correspond to USD 2.3 Bi and will materially contribute to the regional development and well being of the nearby communities and other stakeholders.

May 1, 2010

By Steve Kral

Despite low commodity prices and mining industry cutbacks throughout the world, Peru remains one of the industry’s bright spots. The country’s remarkable economic turnaround during the 1990s remains a model for other developing nations to follow. And the Peruvian government has not forgotten the industry that was instrumental in that turnaround. True, the country has not been spared the effects of the mining industry’s retrenchment that has occurred in other parts of the world. However, foreign mining companies remain committed to doing business in Peru. And the government remains committed to attracting foreign investment and maintaining a strong mining industry. This commitment was evident in September 1999during the 24th Convention of the Institutos de Ingenieros de Minas del Peru in Arequipa, Peru. More than 3,000 mining industry professionals from around the world attended the convention. And Extemin, the accompanying exhibit, featured more than 450 companies, many from the United States, Canada, Australia, South Africa and other countries.

Jan 1, 2000

By E. C. Demsky

This paper describes the large diameter caisson foundation for the upstream guidewall at the Lock and Dam No. 26 (Replacement) Project. The guidewall is supported on two rows of 1.8-m diameter concrete filled caissons. The 28.8 m long caissons are embedded 15.5 m into the foundation material and have an unsupported length of 12.2 m. This paper describes the philosophy and design decisions leading to this unique caisson design. The construction success and problems for the load test caisson will be discussed. The full scale 13,350-kN caisson load test and the associated lateral load tests will be described and the test results presented.

Jan 1, 1989