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By Emerson Lamartine Ferreira

Após a escassez hídrica de 2014, a Agência Nacional de Águas (ANA), objetivando preservar os estoques de água dos reservatórios da bacia do Paraíba do Sul, autorizou, em março de 2015, uma redução de 190 para 110 m³/h na vazão do Canal de São Francisco. A mudança ocasionou o agravamento dos efeitos de intrusão da cunha salina da Baía de Sepetiba no dito canal, elevando os valores de condutividade, que impactou nas operações do complexo siderúrgico da Ternium, pois a água do mar passou a entrar nos sistemas de captação de água bruta. Com o objetivo de contornar o problema, a empresa decidiu implantar uma planta de osmose reversa, a fim de adequar a condutividade da água industrial aos parâmetros das especificações técnicas da planta de água desmineralizada. O presente trabalho descreve a otimização da dita planta à produção de água desmineralizada, que decorreu ainda na redução do número de regenerações das resinas de troca iônica, do consumo de produtos químicos, bem como no reuso do rejeito salino gerado no processo de osmose (Projeto Reuso).

Aug 1, 2019

By G. W. Jones

From evidence made available during the investigation, it was concluded that the first of a series of explosions occurred at 1:15 to 1:20 p.m. September 21, 1951, in an underground vault that housed pressure regulators on the gas-distribution lines that served Brighten. This explosion damaged the pressure regulators and permitted high-pressure gas to enter the distributing mains and individual-service lines. As a part of the gas-distribution system was not provided with means for protection against such excessive pressures, gas gained access to the interiors of many residences in this area and caused a series of disastrous explosions and fires, which took place during a period of approximately 2 hours after the initial explosion in the pressure-regulator vault. Two persons were killed in the first explosion in a residence, and a third person died of a heart attack attributed to the excitement that prevailed during the explosions and fires, Twenty-three persons were listed as injured. Forty-one residences were either destroyed or damaged - 11 by explosion and the remainder by fires, which developed as a result of gas leakage into residences. Fifteen residences were listed as "completely down" or "gutted." Unofficial estimates of property damage ranged from $1,000,000 to $1,500,000. In view of observations made and information obtained during the investigation, recommendations are presented in this report relative to the natural-gas distribution system in Brighton, which may be helpful in the prevention of similar accidents in this and other communities.

Jan 1, 1952

By M. Tangstad

Keywords: Pyrometallurgy, ROMA, Norway, furnace, fines The ROMA project is a competence project on optimizing the usage of raw materials and energy in the ferromanganese, silicon, and aluminium industries. One of the items investigated in this project is the effect of fines on the furnace, and the usage of agglomerates versus lumpy ore. From lab-scale experiments it is shown, that for the charge to agglomerate in the furnace, the charge has to be exposed to a temperature higher than about 1200°C, independent of fines content. The fines less than 1 mm also showed higher agglomeration properties, compared to 2?4 mm, which showed no agglomeration property at all. The properties of agglomerates are very dependent on the pre-treatment of the agglomerate. Sinter and pellets, which have been heated to high temperatures, show a better strength, but also a lower CO reactivity. Sinter also shows a lower melting temperature compared to the ore.

Jan 1, 2011

NEW MEMBERS The following list comprises the names of those persons who became members during the period Oct. 10, 1916 to Nov. 10, 1916. ANCHOR, HANS C., Supt., Dome Extension Mines Co., Ltd., South Porcupine, Ont., Canada. BABCOCK, EARLE J., Dean, College Of Min. Engrg., State Univ. Of N. Dak., Grand Forks, N. Dak. BIDDIS0N, P. McDONALD, Construction Engr., The Ohio Fuel Supply Co., 52 W. Gay St., Columbus, 0. BOISE, PAUL T., Asst. Mgr., Stimpson Equipment Co., Felt Bldg., Salt Lake City, Utah. BOURNE, RALPH H., Vice-Pres Whiting Foundry Equipment Co., Harvey, Ill. BROWN, EDWARD OTTO FORSTER, Min. Engr., 706-707 Salisbury House, London, E. C., England.

Jan 12, 1916

Coal Preparation Research at Turkish Coal Enterprises (TKI)

Sep 13, 2010

By Z. T. Bieniawski, E. H. Skinner, R. A. Cummings, F. S. Kendorski

INTRODUCTION Caving Mine Drift Support Design The support of production drifts remains a high-cost item facing the developer or operator of an underground caving mine. Support costs are incurred well in advance of ore production, and there is a strong need to minimize these pre-production commitments of capital. Due to the extensive rock loads that normally develop during the caving process, the support used in caving mines is typically quite heavy and therefore costly. The process of designing this support increasingly makes use of basic tunneling principles, but is hindered by the still-incomplete state of knowledge of rock behavior in caving mines, and high variability of geological conditions in caving orebodies. Caving mines differ from tunnels in that the deformations and rock loads induced are transient and dynamic in occurrence, and are normally large in magnitude, often well in excess of rock mass strength. As opposed to tunnels, caving mine layouts are more intricate, and the methods and effects of construction ordinarily are not as closely monitored. Safety factors in mining tend to be lower and rock masses tend to he weaker. These aspects prevent strict application of tunnel design technology to caving mine drift support, with the result that mine drift supports are commonly designed chiefly on the basis of experience at other mines. Mining procedures at caving mines are evolved in response to site-specific requirements, to the extent that there are really as many caving methods as there are caving mines.

Jan 1, 1983

By S J. Clarke, C S. Walker

The South West Rail Link (SWRL) project involved construction of a rail line to service new residential areas in south-west Sydney. The 11 km rail line is conveyed through a short tunnel at shallow depth where it crosses beneath the eight lanes of the Hume Highway. The underpass location is one of the most heavily trafficked within Sydney’s motorway network.The New South Wales Roads and Maritime Services (Roads and Maritime), as the owner of the highway asset, had the responsibility of managing the risks to the highway and traffic associated with the tunnelling project from the pretender stage through to completion. This paper considers the primary risks and mitigation measures employed, including geotechnical investigation, and development of appropriate construction constraints and concept design of an extensive real-time survey system to monitor pavement deformation during the tunnel works.The geology comprises fresh Minchinbury Sandstone in the tunnel invert and side walls, and variably weathered Bringelly Shale in the haunch and crown. Few tunnels have been excavated in these rock types in Sydney, and there is little information relating to the in situ stresses and stress-relief deformations in these materials.During tunnel construction the monitoring data indicated unexpected surface heave of up to about 24 mm. A multiparametric back-analysis of the deformation data is presented, which provides information on the deformation mechanisms and key geotechnical parameters, including rock mass modulus and in situ stresses.The approaches and methodologies developed for the SWRL underpass were effective in maintaining the safe operation and traffic capacity of the highway throughout the construction period, and the analysis of the monitoring data provides a useful reference for similar future projects, or projects constructed in similar ground conditions.CITATION:Clarke, S J and Walker, C S, 2014. Deformation mechanisms of the South West Rail Link underpass beneath the Hume Highway, in Proceedings 15th Australasian Tunnelling Conference 2014, pp 631–640 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Sep 17, 2014

By Steve Kral

It seems that mining has been in the doldrums for awhile. Except for gold, metals prices remain depressed. And economic conditions in the United States and around the globe have put governments in a financial bind. This affects new building and infra-structure repairs, which, in turn, have a major impact the building materials industry. Add to that the severe environmental and regulatory restrictions placed on the mining industry in developing new mines and expanding existing ones. It’s enough to make a mining engineer/geologist/metallurgist go sell real estate. So why do those employed in the mining industry stay in the business and remain optimistic? Many of them will say that they have been through down cycles before and know that an upswing is in the offing. They also know that society will always need the commodities they produce. And they love the challenge. The challenge in mining’s case is producing commodities as cheaply as possible, in an environmentally sound manner and improving the quality of life in the communities where they work.

Jan 1, 2003

By J. Walden, S. Rhoades, R. E. Miller, R. Gibbs, P. Boman

Accelerometers and pressure transducers mounted in suspension components can be used to monitor the ride of haulage trucks. Presently, it is difficult to tell what caused a jolt to the truck using either pressure or acceleration data alone. When information from a Global Positioning System is recorded at the same time as shock pressures or acceleration data, then the exact location of an event can be determined. Mine management can then determine what caused the jolt to the truck.

Jan 1, 1999

By D. Brosnahan, J. Gathje

Newmont Metallurgical Services (NMS) recently acquired a Scanning Electron Microscope (SEM) with a JKMRC/FEI Mineral Liberation Analyzer (MLA). With the MLA software package, raw particle image and X-ray data can be converted into particle mineral maps and bulk and liberation data can then be calculated for minerals of interest. This type of quantitative mineralogical data can then be used for a wide variety of applications. Ore characterization with MLA can be carried out for existing or processing plants in development. MLA characterization of laboratory test products provides valuable liberation information that assists the research metallurgist in better planning and developing process treatment options for various ore types. This paper describes the use of MLA characterization in a copper flotation test program where the use of various testing options for arsenic depression was being evaluated.

Jan 1, 2007

By E. R. Maize

This report is the third of a series on convergence of roof and floor in coal mines and subsidence of surface that accompanies it. The first papery dealt with extraction in a mechanized mine (Montour 10) having relatively short rib lines that retreat rapidly. The second 6/ dealt with extraction in a mine (Crucible) in which coal was loaded by hand and in which the rib lines were long and slow-moving. The present report deals with a mine (Gibson) in which conditions approximated those in the Crucible mine, except that the distance between room centers was considerably less and the pillars were narrower in consequence. Moreover, the average cover was less and the studies were made under the steep hillside of a stream valley compared with a gently rolling surface over the portions of the second mine studied. Gibson mine lies in the east-central part of Washington County, Pa., approximately midway between the Montour 10 and Crucible mines on a north-south line. A cooperative agreement covering the work was made with the Hillman Coal & Coke Co. through W. L. Affelder, vice president. This paper describes the methods used in the investigation, gives excerpts from the data obtained, and offers such generalisations as appear to be justified.

Jan 1, 1940

Recently discovered Carboniferous bentonites are variable in charadeI and thickness, but being altered aeolian, ash-fall tuffs, they are probably extensive. Most are the Ca-montmorillonite type without the natural swelling characteristics of the Wyoming deposits, but their situation, thickness, and response to beneficiation through cation exchange may give them some potential as sources of future economic deposits.INTRODUCTIONLoughnan and See (1959) gave an account of bentonites and fuller's earth deposits of New South Wales. The most likely potential industrial sources were those occurring in the uppermost formations of the Newcastle and Singleton Coal Measures (Permian) in the Hunter Valley and deposited during epochs not marked by strong contemporary vulcanicity.One feature of the record of known occurrences at that time was the absence of bentonites from the thick volcanic sequences of the Carboniferous, but since this paper appeared, many bentonite beds have been discovered by the writer in the Carboniferous facies formerly known as the "Kuttung Series".The purpose of this contribution is to report briefly on the occurrence, genesis, mineralogy, and economic potential of these deposits which augment possible sources of bentonite near major industrial centres on the eastern seaboard.The potential world demand for bentonite would increase markedly with the trend to pelletization in the steel industry, if its use in this field became more general. More detailed mineralogical studies will be presented in later publications.STRATIGRAPHIC DISTRIBUTIONBentonite occurs at irregular intervals throughout a thick sequence of dominantly continental, plant bearing strata...

Jan 1, 1965

By Martin J. Gavin

The results of investigations of the oil-shale resources of the United States were first published by the United States Geological Survey in 1915.1 Other reports 2 have followed. These reports, investigations by private individuals and corporations, and the beginning of the development of an oil-shale industry in this country have aroused considerable interest in the possibilities of these shales as a commercial source of hydrocarbon oils. The Bu- . reau of Mines bas appreciated these possibilities, and since 1916 one or more of its engineers have given all or part of their time to investigations relating to the treatment of oil shales. A short pamphlet a containing general information on the possibilities of oil shale in this country, particularly the shales of the Rocky Mountain district, has already been published. This pamphlet gives methods for assaying the shales of oil and ammonia and contains a bibliography for the use of those desiring to search the literature.

Jan 1, 1924

By D. Saramak

The proposal of the nip zone angle determination in HPGR crushing process is presented in the paper. Knowledge of the nip zone angle value, in turn, makes it possible to determine the real maximum pressing force in the high-pressure comminution. Two methods of determination of this maximum pressure were proposed and verified. The first method is based on the roll?s geometry, and the change of the HPGR chamber?s volume together with the roll rotation, while the second one considers the outlet gap width impact. Results of the nip zone angle calculations according to both methods are similar and show convergence with the real operating conditions. The verification was carried out in a piston-die press, and experimental results show that methodology of the nip zone angle determination presented in the paper has its practical confirmation. A proper determination of the nip zone border makes it possible to calculate the comminution probability of given type of material and is a basis for the HPGR crushing process modeling and optimization. Keywords: HPGR, comminution, nip zone, ore processing

Sep 1, 2012

The effect of microwave radiation on the processing of Palabora open pit ore has been investigated. Significant reductions in Bond work index are demonstrated for microwave treated samples. Reductions in work index were found to be sensitive to applied power level and method of application. After single stage magnetic separation tests, improvements in recovery of FeO were noted. However, these were curtailed by oxidation of the magnetite species as a result of continued heating. The effects of microwave radiation upon the recovery of copper after froth flotation were also quantified. Small initial increases in recovery of copper were note dafter microwave treatment. However, with prolonged exposure, recovery was found to decrease. Overall recovery of copper was not affected except for samples treated for extended duration. The influence of microwave treatment upon the conventional Palabora grinding circuit has been quantified with the use of USIMPAC software. Conclusions are made regarding the economics of microwave treatment for this ore. Keywords : Microwave; Grinding; Magnetic Separation; Flotation; Economic Analysis

Jan 1, 2000

By Diogo R. Prado, José Aurélio M. da Luz

Drying operation can have a major importance in a mineral processing undertaking. The proper sizing of dryers can ensure the specified dewatering level without energy wastage. However, often the sizing of fluidized bed is done disregarding the actual residence time distribution (RTD) of the particles inside the reactor. In this case it is usual to adopt the average residence time as a design criterion. In this work, we have quantified the effect of residence time distribution on drying, ensuring that a previously adopted fraction of the particles remains inside the reactor for the required time lapse needed for drying. Design criteria such as particulate flow rate and drying time, taking into account the statistical distribution of residence time was studied, matching the thermodynamic and fluid dynamic aspects of the drying process. Experimental tests carried out have confirmed the RTD for a teetering bed as the same for a canonical ideal mixing system. Although the fluidized bed volume using the proposed formulation was higher than that found for the average time based procedure, the efficiency gain in drying has proven advantageous.

Jan 1, 2014

By Mark M. Petersen

As part of the addition of eight new combined cycle generating units at the Florida Power & Light Sanford Plant, 2,129 piles were to be installed. The existing plant elements were supported on driven piles, and the variation in pile lengths during previous work, as well as available subsurface information, indicated a complex stratigraphy. At the request of the owner, the designer/construction manager developed a program to evaluate the use of pressure-grouted displacement piles. A pre-design load test program in areas that represented the apparent extremes in subsurface conditions indicated that the system was feasible; however, the presence of existing features that were to be demolished later precluded the clear delineation of subsurface conditions in advance of construction. A contract was negotiated with the pile installer based on the best estimate of potential pile lengths, with modifications to pile lengths to be set based on additional exploration. A total of 52 cone penetration soundings and five load tests were performed immediately prior to and during pile installation to establish correlations between the CPT data and pile performance. Pile depths were set based on these correlations. Pile installation was completed 6 weeks ahead of schedule and 15 percent under the original budget estimate. This paper documents the evaluation of pressure-grouted displacement piles as an emerging technology, and illustrates the benefits of a close working relationship between the owner, designer, and pile contractor at a site with variable subsurface conditions.

Jan 1, 2002

By M. P. Nesterov

The method of predicting the time-dependent surface subsidence for gently-inclined potash deposits where total extraction using various sizes of yielding bamier pillars was discussed.

Jan 1, 1998

By C. David Mann

Metal prices continued to improve in 1964, resulting in the opening of new mines and re- activation of old ones. Larger and deeper shafts are being bored. At the AEC's Nevada Test Site, a 72-in. diam shaft is being bored to 3200 ft. In New Mexico a 1650-ft shaft was bored with a 48-in. bit, then reamed to 124 in. to 935 ft, and 102 in. to 1650 ft. Deviation was only 26 in. In California a shaft sinking machine has been developed which combines drilling and mucking equipment into one mobile, integral unit.

Jan 2, 1965

By Alex Grenoble, Alex Reeb, George Filz, Farzad Abedzadeh

"This paper summarizes available information on the characteristics and properties of deep-mixed soilcement produced by the wet method. The topics covered in this paper include: unit weight, unconfined compressive strength, strength variability for field mixed materials, influence of curing time, influence of consolidation pressure, Young’s modulus, differences in strength and stiffness between small and large samples, creep deformations, Poisson’s ratio, and tensile strength. In addition, this paper discusses the development of design considerations and recommended property values for a project that uses soilcement to protect an existing dam penstock from loads applied by an overlying stability berm. Some of the key recommendations for the deep-mixed soil-cement to be used in this project are that (1) a curved strength envelope that includes tensile strength can be used in the analysis, (2) the stress-strain and strength properties can be characterized using Duncan and Chang's (1970) hyperbolic model, and (3) a specification based on the median unconfined compressive strength value is appropriate.INTRODUCTIONFor many projects, including foundation and embankment support, deep mixing can be designed based on simplified procedures and following standardized guidelines (e.g., FHWA 2013). However for unusually complex or critical projects, it is often necessary to perform numerical analyses, and in order to perform these numerical analyses well, a thorough understanding of the material properties is needed.This paper summarizes information on the characteristics and properties of deep-mixed soil-cement produced by the wet method, and it discusses the development of design considerations and recommended property values for a specific project, herein referred to as the penstock project, that requires numerical analyses. For the penstock project, a horseshoe-shaped enclosure of soil-cement is being considered beside and above an existing dam penstock to protect it from loads applied by an overlying stability berm that will be constructed for seismic remediation. The concept is to use soilcement created by the deep mixing method along the sides of the penstock and to use compacted soilcement above the deep mixing to create the crown of the protective soil-cement zone around the penstock. For this application, the soil-cement stiffness, rather than its strength, is the controlling design parameter. To achieve the necessary soil-cement stiffness, the strength will be high enough that the factor-of-safety values against instability along potential failure surfaces passing through the soil-cement are high. Following conventional practice, the soil-cement acceptance criteria will be based on the unconfined compressive strength, and the specified strength will be selected to produce the desired modulus value."

Jan 1, 2015