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By Dagoberto Brandão Santos, Marcus Vinícius Pereira Arruda, Fernando de Souza Costa, Túlio Magno Fuzessy de Melo

The development of advanced high strength steels (AHSS) is motivated by the automotive industry demands for higher strength steels with better formability and stretch-flangeability to avoid fractures during parts forming. In response to this, the new steel grades must have special microstructures in terms of constitution, morphology, distribution and hardness, which are strongly dependent on the chemical composition of the steel sheet and its processing, especially in the continuous annealing stage, in the case of cold rolled sheets. In this study the influence of the annealing heating rate and intercritical temperature (IT) on the microstructural evolution and the final hole expansion ratio of a cold rolled 980 MPa AHSS grade was evaluated. The annealing process was simulated using a Dilatometer and a Gleeble machine, and the microstructures were characterized using scanning electron microscopy, electron backscattered diffraction (EBSD) and nanohardness measurements. The increase of heating rate resulted in an overlap between ferrite recrystallization and austenite formation, changing the austenite morphology from a random to a fibrous distribution, while a higher IT resulted in more homogeneous microstructures and higher hole expansion ratios. This microestructural homogeneity, confirmed by nanohardness measurements, suggested that the difference in hardness between ferrite and the second phase affects the micro-void formation and crack propagation during the hole expansion test.

Oct 1, 2019

By T. G. Joseph, A. Chamanara

ABSTRACT: The chicken and egg scenario — where adverse truck motions cause ground deterioration and poor ground profiles cause adverse truck motions — is a downward deterioration spiral dominating our industry. If we remove one action, the reaction stops. A simple truck to excavator load data analysis and wireless communication system is outlined, which will provide visual assistance to the excavator operator in achieving improved load placement and balance in a truck body. This will reduce subsequent hauler duty cycle adverse motions and g levels that contribute to structural fatigue, higher tkph, reduced tire life, and ongoing maintenance of haul roads.

Jan 1, 2012

By G. B. Sazuyer

DEVELOPMENTS respecting beryllium during the past year have been sufficient to center attention on it as likely to be the most important of any of the chemical elements that have recently found a place for themselves in technical industry. This importance is only potential, however, largely because adequate supplies of beryllium ore will be necessary. The beryllium industry will be only as great as the mines which support it. To find and develop large mines will be the problem. Chief of the immediate commercial developments in the United States is beryllium-copper and its espousal by Anaconda and Riverside even at present high prices. According to the pamphlets of these companies, it ap¬pears that beryllium is to copper nearly what carbon is to iron. When one considers that the tensile strength of pure copper is about 33,000 lb. per sq. in., but that the addition of 1.5 to 2.5 per cent of beryllium produces a heat-treatable alloy with a maximum tensile strength of 220,000 lb. or over, the analogy to carbon and iron is made strikingly, clear. Striking among the properties of beryllium-copper is its resistance to fatigue, claimed to be equal or superior to that of spring steel. It needs little imagination to foresee a great industry for this alloy alone.

Jan 1, 1934

By David B. George

Kennecott recently completed an $880 million modernization and expansion of its smelter and refinery to process all concentrates from the Bingham Canyon mine. This is the first application of Kennecott-Outokumpu Flash Converting. Molten material movement by overhead cranes is eliminated and high levels of oxygen enrichment result in very low process gas volumes and exceptionally control of sulfur oxide emissions. All existing in-plant hygiene, safety, and environmental regulations will be met and the smelter is positioned for anticipated more stringent future regulations. Sulfur capture is 99.9 percent resulting in sulfur dioxide emissions less than the 112 kg/hr Air Permit limit, making the smelter the cleanest in the world.

Jan 1, 1996

By J. L. SCHUELER

THE writer has reread Mr. Ingalls' interesting article in the July, 1923, issue of MINING AND METAL- LURGY on "The Use of Spelter in Galvanizing." It seems that most writers, in commenting upon coatings of spelter on sheets and wire, dwell upon the thin coatings which these materials carry, and rightly so. However, they seem to forget that until very recently, in the case of wire, the manufacturer did not know how to apply a heavy coating of spelter to the wire, especially if the wire was to be woven into fence or fabricated in some other manner, because heavy coatings of spelter are exceedingly brittle. This is even true in the case of high-grade spelter, but to a lesser degree than with Prime Western. Because of this brittleness, it has been necessary for wire manufacturers to smooth the coating by passing the wire through tightly compressed wiping means of some kind, usually asbestos. This removes all of the excess spelter and allows only a thin coating to remain. The latter, as a rule, is malleable and the wire can be fabricated without material injury to the coating.

Jan 1, 1924

By Zhihe Dou, Yan Li, Qiuyue Zhao, Guozhi Lv, Yan Liu, Hongliang Zhao

"Abstract: How to reduce carbon dioxide emissions has become a vexing problem, meanwhile, there exist high energy consumption and low efficiency problems in the existing CO2 capture and storage technologies. For CO2 comprehensive Utilization, this paper researches a new technology of absorbing the CO2 emission with high alkaline calcium or high alkaline wastewater sludge mineralization of calcium and invent a core device for multi-level jet carbonation. The industrial test has been carried out in China Xinyu slag Engineering Co., Ltd. The wastewater flow is 150m3/h in the pilot scale. The prepared calcium carbonate has a whiteness greater than 90%, particle size less than 150nm. The mineralization of aluminum exhaust with waste carbide indicates that the CO2 absorption rate is greater than 99.0%, CO2 concentration in the exhaust gas is lower than 0.08%, the purity of mineralized calcium carbonate is greater than 99.0% and particle size is less than 100 nm.InstructionAccording to the statistic data from IEA (2009), the carbon dioxide discharge from fossil fuel consumption in China has exceeded it in the US by the year of 2007, China, has become the largest emitter of carbon dioxide all over the world. Meanwhile, the economic scale is still on an increasing trend in the next 50-100 years, leading to a continuous increment in carbon dioxide discharge. According to the international energy agency forecasts, the energy-relative CO2 discharge in China will rise to 11,615 million tons, 91.3% higher than it in 2007. In the year of 2012, the CO2 gross discharge has reached 10,000 million tons, obviously higher than the predicted value. It is a tremendous task to reduce the emission. Non-ferrous metals industry is one of the largest emitters of carbon dioxide among the industrial circle, the whole industry might discharge a huge amount of carbon dioxide (over 600 million tons), in which the electrolytic aluminum industry is the largest energy consuming industry and CO2 emitter. At present, the CO2 discharge has focused by the whole world due to the environmental problems it causes; meanwhile, supplement of new carbon source is needed due to the exhausting oil and coal resources, so that various countries in the world are attaching importance of the recycle and purification of CO2. Many countries are studying on the cyclic utilization of carbon dioxide. Gas CO2 is mainly applied in chemical, pharmaceutical raw materials, beverage filling agent, refrigerant, inert medium, solvents, pressure source, the welding protective gas, antioxidant and fire extinguishing agent, etc. Solid CO2 is mainly applied in penicillin production, fish, cream, ice cream and other food storage and transportation at low temperature, etc. nowadays, such methods as absorption method, membrane separation, adsorption, etc. are widely used to recycle CO2, with such problems as high investment cost and technical constraints etc."

Jan 1, 2014

By Mihaita Matei

An adaptive approach to control the deformation in tube hydroforming process is presented. This requires: the use of an existing non-linear FE software (ABAQUS) that incorporates a user material model (VUMAT), the development and implementation of an adaptive control strategy to coordinate the internal pressure and the axial load so as to prevent fracture and wrinkling failures (knowledge-base controller) and the application of the developed adaptive simulation approach for finding the optimal loading path required to hydroform a defect-free part with as uniform thickness distribution as possible (user's load subroutine (VDLOAD). In order to validate the approach, the case of conical hydroforming and the case of bending followed by hydroforming component is discussed.

Jan 1, 2011

By R. T. Johansen, R. J. Heemstra

In water flooding the gradual accumulation of insoluble materials on the sand face causes the injection pressures to increase while decreasing the amount of water injected . This plugging material often is composed primarily of insoluble precipitates of calcium , iron , and magnesium . Treatment with sodium tripolyphosphate ( STP ) either eliminates or reduces the formation of precipitates . Field tests are discussed showing the almost immediate effects of using STP in the injection water . Methods of treatment , solubility of STP in fresh water and brines , and precautions to observe when starting to treat a waterflood with this chemical are given . Laboratory data show that the preferential wettability of a crude oil for reservoir rock can be reversed by adding a small amount of STP to the flooding water . This reversal in wetting tendency should not only decrease the injection pressures but also increase oil recovery by improving the sweep efficiency of a water flood .

Jan 1, 1964

By Ernest M. Spokes

Starting in 1980, a committee of the National Research Council studied the question of why some underground coal mines are safer than others and what could be done to improve the ones with poorer performance. The results indicated that safety is improved by management commitment to safety, by cooperation between labor and management on safety matters, and by quality training of employees and managers. Younger mines have higher accident frequencies, but are less likely to be killed or permanently disabled by a lost-time accident. Methods for improving safety performance are proposed.

Jan 1, 1983

By J. D. Davis

THE carbonizing properties of one medium- and and five low-volatile coals from West Virginia and one high-volatile A and two medium-volatile coals from Pennsylvania were determined by 800° and 900° C. BM-AGA carbonization tests and expansion tests in the sole-heated oven. Plastic properties of the coals and the yields and quality of their cokes and other carbonization products were determined. The low-volatile coals comprised a mine and a coke-plant sample of Pocahontas No. 6-bed coal from the. Black Eagle No. 1 mine, Wyoming County, W. Va.; a mine sample of Pocahontas No. 6 bed from the Louisville mine, Mercer County, W. Va. ; Davy Sewell bed was sampled at the Twin Branch mine, McDowell County, W. Va.; and Fire Creek bed was sampled at the Dunedin No. 1 mine, Raleigh County, W. Va. The medium-volatile coals were from the Fire Creek bed, Laurel Creek mine, Greenbrier County, W. Va.; Lower Kittanning bed, Springfield No. 4 mine, Cambria County, Pa.; and Upper Kittanning bed, Springfield No. 6 mine, Clearfield County, Pa. The high-volatile A coal represented the Upper and Lower Freeport beds, Kent Nos. 1 and 2 mines, Indiana County, Pa. In addition to the coals listed, high-volatile A coal from the Pittsburgh bed, Warden mine, Allegheny County, Pa., a standard blending coal, was used in blends in this investigation.

Jan 1, 1950

By Alvin Kaufman

Geothermal plants are competitive with conventional units. A geothermal plant can produce electric energy for 6.70 mills per kwhr, compared with 6.96 mills for coal, 6.74 mills for oil, and 7.04 mills for gas. These costs include fixed and variable charges. Potential for geothermal power exists in the Western United States, Alaska, and possibly Hawaii. Assuming that the current downward trend in cost per kilowatt of coal will cease and that the relative cost of gas and oil, already trending upward, may rise considerably more, geothermal energy will be utilized where available, in producing electric energy. It will be used in California first because it is directly competitive with gas-and oil-fired installations there. A long-term appraisal is difficult because little is known about the sources of geothermal power and the electric generating capacity which the steam fields will support. However, a market for geothermal steam-generated electricity exists within the Western States.

Jan 1, 1964

By Alvin Kaufman

Geothermal plants are competitive with conventional units. A geothermal plant can produce electric energy for 6.70 mills per kwhr, compared with 6.96 mills for coal, 6.74 mills for oil, and 7.04 mills for gas. These costs include fixed and variable charges. Potential for geothermal power exists in the Western United States, Alaska, and possibly Hawaii. Assuming that the current downward trend in cost per kilowatt of coal will cease and that the relative cost of gas and oil, already trending upward, may rise considerably more, geothermal energy will be utilized where available, in producing electric energy. It will be used in California first because it is directly competitive with gas-and oil-fired installations there. A long-term appraisal is difficult because little is known about the sources of geothermal power and the electric generating capacity which the steam fields will support. However, a market for geothermal steam-generated electricity exists within the Western States.

Jan 1, 1964

By S. J. Jung

Determining the correct combination of mix components and water for high-density paste backfills with the transport and deposition properties necessary in a mining operation is a difficult task. Rheologic properties cannot be determined without conducting full-scale pumping tests, and data from existing tests are very limited. The following presents the findings of investigations undertaken to determine if paste backfill rheology can be determined using existing techniques and which mix and system variables have the greatest influence on transport pressure loss. Data from lab-oratory-scale pumping tests were used to produce a rheologic model of flow behavior for comparison, and a statistical analysis was conducted to determine the most significant factors affecting transport pressure loss.

Jan 1, 1994

By Kenji Koga

In order to derive the population distribution of gold nanoparticle morphologies as a function of size, highresolution electron microscopic (HREM) observations and structural analyses were done for over 4000 particles (3-18 nm) grown by an inert gas aggregation (IGA) source using helium. To obtain structural features threedimensionally and not to skip high-contrast images, twenty photos were taken for each particle by changing tilting angle of a specimen holder in combination with the through-focus procedure. For the reliable structural determinations, HREM images and their tilting sequences were directly compared with multislice-simulation results for icosahedral, decahedral and face-centered cubic morphologies, and finally the population distribution of each morphology was obtained as a function of size. In the present sample, icosahedral particles were dominantly populated over the whole observed size range and decahedral particles with non-spherical truncated bi-pyramid shape were secondly dominant. Even though a large number of sampling has been done, few crystalline particles were observed.

Oct 1, 2003

By F. E. Brantley, D. A. Martin

Synthetic zeolites were tried as selective adsorbents for recovering sulfur dioxide from synthetic gases and gases produced from gypsum decomposition . Initial adsorption tests , using the synthetic gases , indicated that three of these compounds , having sulfur dioxide capacities of up to 29 grams per 100 grams of adsorbent , were satisfactory . Regeneration studies showed that over 90 pct of the sulfur dioxide desorbed from the loaded beds was of sufficient purity for direct liquefaction . However , all zeolites tested lost adsorptive capacity with repeated use . The zeolite determined to be the most promising in the preliminary synthetic gas tests was also evaluated for capability in adsorbing sulfur dioxide from gases produced by the thermal decomposition of gypsum . Despite small amounts of hydrogen sulfide in the gypsum decomposition offgas , good adsorption of sulfur dioxide was attained . The economic practicality of utilizing zeolites for sulfur dioxide removal from industrial gases was not evaluated , but the technical feasibility was demonstrated .

Jan 1, 1963

By R. S. Shepard

The closing remarks of a paper which I presented at the annual AIME meeting at Dallas, Texas during February of 1963; contained a forecast of increased activity in trackless underground ore mining which finalized that presentation. At that time, HAD I been peering through my brightest rose colored glasses, I could not have foreseen the unprecedented rapidity of acceleration of underground ore mining methods which has since ensued. From Death Valley, California diagonally to St. Johns, New Foundland; from Australia to Africa to Sweden to France and Germany; from South America to Southern Mexico to Northern Saskatchewan and Northern Manitoba the expansion of trackless underground ore mining methods has probably progressed at a faster rate than any other revolutionary' change in the history of underground ore mining.

Jan 1, 1967

By James R. Dunn

The mineral industry" has made and will continue to make important contributions to the growth of our economy. However, the industry is presently under continuous and increasingly severe attacks by organizations and individuals interested in the preservation of our environment. Yet neither the public interest value of preservation nor the public interest value of our mineral industry is known. In the absence of such values, judgments about best land use where minerals are involved are nearly always made on emotional grounds. An example of the sort of problem that has been created is in the New York Metropolitan Area. Because of institutionally-created shortages stemming largely from zoning decisions and building over deposits, the effective cost of fine aggregate delivered at dockside at Manhattan rose from $2. 65/cubic yard in July, 1969, to $4.10/cubic yard in May, 1970, this in spite of approximately ;l0,000 years of reserves on Long Island. The cost of fine aggregate for New York City alone has "Increased over $S million annually within one year, with the cost increase for the Tri-State Metropolitan Area (coastal Connecticut, New Jersey, and New York)" exceeding $10 million annually. The ab0ve situation has created a cost increase which is clearly the result of non-conservation of a mineral resource. That is, in readily measurable values, it Is costing the public about $10 million per year because good conservation practices were ignored-a public-interest loss. Admittedly, this is not the whole story because the public is simultaneously obtaining other values from the land surface that would otherwise have had to be dedicated, temporarily to be sure, to mineral recovery-a public-interest gain. However, the point is that we do not know where the balance lies-the net public interest value; it may lie one way for deposits zoned out of existence by a growing suburb, another for areas designed as permanent greenbelts, and still another for areas under new highways

Jan 1, 1971

By A. S. Ibrado

Research investigations on the chemistry of the adsorption of gold cyanide on activated carbon have mostly reduced the role of activated carbon as the provider of the large surface area needed for adsorption. Most do not go beyond suggesting that oxygen functional groups on carbon play a key role in the adsorption process. Our research shows that the nature of the material, specifically its structure, is a crucial factor in the adsorption equation. To delineate the effect of adsorbent properties, gold cyanide was adsorbed on a series of carbonaceous adsorbents, including lignite, coals, anthracites, carbon blacks, graphite and activated carbon, which covers wide variations of composition, surface acid group content, and degree of graphitization. The results show that the adsorption of gold cyanide per unit area of adsorbent is not related to the amount of oxygen groups on the surface or even the total oxygen content of the material. However, they show very strong correlation with the degree of graphitization of the adsorbent, which indicates that the graphitic plates of activated carbon play the most important role. The findings suggest that majority of the adsorption occurs on the plate faces of the graphite crystallites of activated carbon.

Jan 1, 1992

By T. Moloane, C. Bergman, Heloise Thiele

"A pilot test campaign was undertaken to evaluate dense medium cyclone separation efficiencies on samples of iron ore fines (-1mm +300µm). Evaluations were done using both gas and water atomised FeSi types across a range of operating conditions in the presence of slimes build-up. A Mineral Liberation Analyser (MLA) was used to measure size, density, shape and liberation data of DMS feed and products. The results of the test work were used to obtain parameters for modelling of the partition size/density response. The findings indicated that accurate density characterisation of the feed ore is essential in understanding product quality and recovery, particularly due to the effect of porosity and micro-inclusions. A significant off-set between cyclone underflow density and separation cut-point (D50) was found indicating that relatively low feed media densities (about 3.4g/cm3) are required to achieve high density cutpoints of over 4.0g/cm3. In agreement with CFD modelling, the separation quality is dominated by viscous effects, hence FeSi type and slimes content will need to be carefully controlled to ensure efficient separation.INTRODUCTION In the South African context, future resources of hematite are expected to be both of lower head grade and will contain a higher content of banded iron formation (BIF) (1). These ores may require finer crushing in order to liberate the high-grade fractions and will thus increase the amount of -1mm material to be processed. In order to efficiently upgrade these materials, it becomes necessary to re-examine both traditional and novel processes to treat material finer than 1mm in size. These include spiral and up-current classifiers, wet high intensity magnetic separation processes, Reflux classification and potentially includes dense medium separation (DMS). This study presents a technical evaluation of fines DMS using a mineralogically-based particle tracking analysis method (PTA) to calculate efficiencies of separation."

Jan 1, 2018

By Ali Kucuk, Bekir Karasu, Keriman Karaveli Pekkan

"Zircon (zirconium silicate) is the main opacifier of glossy, opaque, white colored, frit-based wall tile glazes. However, zirconia containing frits employed in the preparation of these glazes increase the production cost and therefore, limit zircon usage as a raw material at industrial scale. With the present study, it was searched whether borax solid wastes could be evaluated as a component in the starting relevant frit recipes. The wastes were obtained from Eti Maden Kirka Boron Company of Turkiye. Frit production, glaze preparation, application, and fast single-firing of glazed wall tiles were conducted under laboratory working conditions in Anadolu University, Department of Materials Science and Engineering laboratories. Beside standard tests applied to the final glazed wall tiles, color and gloss analyses of the fired glazes were conducted with a spectrophoto-meter and a gloss-meter. Characterization of these newly produced glass-ceramic glazes was made by X-ray diffraction (XRD), scanning electron microscopy (SEM) and energy dispersive X-ray (EDX) techniques. IntroductionFrits are the indispensable constituents of most industrial glazes which mature at temperatures below 1150 °C [1]. In the traditional opaque glazes used in wall tile industry, opacity usually originates through hardening of glass matrix by adding high amounts of zirconia containing frits into the glaze batch [2]. Nowadays, researches point out that certain type of glass-ceramic layers can be alternatively employed as tile coatings lowering the use of zirconia containing expensive opaque frits. A rather high crystallization capacity of glass- ceramic glazes due to zirconia presence in glass network makes them suitable candidate as a glaze coating with a desirable micro-structure. One of the best methods to obtain an opaque glaze surface is to induce a crystal phase in the coating, whose refractive index differs significantly from that of the glassy matrix. The opacity of such coating is determined by the diffusion, refraction and reflection of light through the layer containing emerging crystals, and the degree of opacity mainly depends on the size and quantity of crystals. The development of glazes not consisting of expensive or toxic components is of special interest [3]."

Jan 1, 2008