Search Documents

By S. Mostaghel, V. Hernandez, S. Ge

"The automotive industry is under a constant pressure to reduce the weight of vehicles in order to reduce emissions and improve fuel efficiency. As such, there is an ever-growing demand for high strength and high ductility steel grades to meet the need for lightweight automotive components. Over the past decade, the production and application of 2nd and 3rd generation Advanced High Strength Steels (AHSS) as a lightweight material in automobiles has gained significant popularity due to their exceptional mechanical properties. However, the production cost of these high manganese steel remains high, partially due to the need of large amounts of ferromanganese as alloying material in standard steelmaking processes.The current study introduces a new and cost-effective technology for the production of medium- and high-manganese steels, where self-fluxed micro-pellets of manganese ore will be used as the source of manganese that can be injected into the steel bath. Prior to injection, these pellets are subjected to a pre-reduction process using a mixture of H2 and CO gases, where partial metallization of iron and manganese will occur. Direct injection of the pre-reduced micro-pellets provides less volatilization/emission and higher recovery of manganese, and is capable of producing AHSS with 6–18 wt% Mn.INTRODUCTIONAutomakers are constantly searching for lighter, stronger and cheaper materials in an effort to create safer and more fuel efficient vehicles. The introduction of aluminum alloys and polymer composite materials for automotive applications has been carving into what is traditionally one of the most profitable markets of the iron and steel business. The steel industry responded with Advanced High Strength Steel (AHSS)—a family of manganese containing steels which exhibit exceptional strength and ductility."

Jan 1, 2016

By Y. Miron

Previous studies at the Bureau of Mines outlined the hazards of ammonium nitrate-fuel oil (AN-FO) mixtures in the presence of pyrite-bearing ores. The recent trend in the mining industry to strengthen AN-FO by the addition of aluminum metal raised the question regarding the effect of aluminum in AN-FO in the presence of pyrite-bearing ore. Laboratory work, similar to that done previously, demonstrated that the temperature of a self-sustaining reaction in the presence of AN-FO ore-aluminum is not lower than that for a comparable AN-FO-ore mixture. However, as might be expected from known thermochemical data, once initiated, the resulting reactions between AN-FO, aluminum, and pyrite are much more vigorous than those observed for AN-FO and pyrites alone. The temperature required to produce a self-sustained reaction for the combinations tested in this study is 250°±20° F while in the previous Bureau study, reactions were noted, in some instances, at 150° F. The different pyritic ores may be the cause of this variation.

Jan 1, 1976

Fundamental results obtained from research on the properties of the edge surfaces of kaolinite particles (~500 nm) are reported. Of particular significance was the development of the experimental protocol. Well-ordered kaolinite edge surfaces were prepared as an epoxy resin sandwich structure having layered kaolinite particles in the center of the epoxy resin sandwich. Images of the sectioned kaolinite edge surfaces were examined by atomic force microscopy (AFM), and the average thickness of kaolinite particles in this study was determined to be 38.3 nm ± 11.7 nm. Furthermore, the surface charge of the kaolinite edge surfaces was evaluated with a super sharp Si tip. The point of zero charge (PZC) of the kaolinite edge surface was determined to be below pH 4, in contrast to the traditional view that the edge surfaces of kaolinite particles may carry a positive charge at pH 4. This lower PZC of the kaolinite edge surface was attributed to the lack of isomorphous substitution in the silica tetrahedral layer when compared to the PZC for the muscovite edge surface. Our results are consistent with the particle aggregation and flotation behavior of kaolinite, and should provide the basis for improved flotation strategies leading to the efficient recovery and utilization of mineral and energy resources.

Feb 23, 2014

James GayleY, New Pork City (communication to the Secretary*) :—The main thing that is sought after in this matter is that all purcliases shall be made by analysis. This is done already in special lines, as in the manufacture of various grades of steel in which phosphorus, silicon and sulphur are specified within narrow limits, and I quite agree with Mr. Cook that specifications, which are over-rigid in unessential particulars, should be avoided, as they defeat their own purpose because unreasonable requirements permitting no variation are practically not fulfilled, and it is impossible to specify grade

Jan 1, 1905

By I. Kirman, B. Waters

World wide applications for nickel use will be summarized and examples of those uses given. Nickel products are critical to many important aspects of modern society. These products are just as important for modern China as they are in other parts of the world. It is argued that future pattern of nickel use in China should be expected to be very similar to that in the rest of the developed world. Total use of nickel in products in China is already very large. In 2004, it was the largest market for stainless steel (nickel containing) in the world. A survey of Chinese stainless steel applications will be presented. Current high nickel prices have revived speculation about substitution, particularly for nickel containing stainless steels. The presentation will discuss some of the complicating factors that need to be taken into account when considering substitution. These factors are as valid in modern China as they are in other developed economies. Recent substitution efforts and the reaction to them will be examined. The Nickel Institute position regarding appropriate application of the various grades of stainless steel will be discussed. Price-motivated substitution in China, and elsewhere, will occur but it is argued that the extent will probably be limited.

Jan 1, 2005

By C. F. Starr

This paper deals with the various types of cable in use in mines, with special attention paid to their construction. There will be a few comments regarding the different insulants, jacketing materials and armouring used, depending on their application. Governing standards and the differences therein will also be discussed.

Jan 1, 1969

By Clebson Joel Mendes de Oliveira

Sulfur control in steel have been challenging process experts since the discovering of it deleterious effect on most of steel product properties. To separate this slag from hot metal is mandatory to complete desulfurization process. The preferred method is to skim hot metal surface physically removing the contaminated slag, attributing to the operator the evaluation of skimming efficiency. Thus, we present a new lower cost system using image processing methods foreseeing a future full automation skimming process.

Aug 16, 2017

By Y. J. Yu, C. D. Zhang, Y. S. Zhao, W. G. Liang, Y. D. Geng, J. L. Bi

"In this study, the coefficient of thermal expansion (CTE) and thermal conductivity (TC) of shale in two perpendicular directions, vertical and parallel to the bedding of the rock, are firstly measured by experiment. The experimental results show that the CTE of the shale in the vertical direction is 1.69 times as much as that in the parallel direction, while the TC in the parallel direction is 1.83 times larger than that of the vertical direction. Based on the no initial strain assumptions, numerical simulations for the thermal cracking in shale are carried out with the obtained coefficients. Using finite element method and thermal-mechanical coupling theory, two fracture mechanical parameters, KI and J-integral of the shale are also analyzed for the shale thermal fracturing. The simulation results show that both KI and J-integral reach the maximum when the fracturing angle equals to 0° in the shale, namely parallel to the bedding direciton. It is also found that the two fracture parameters decrease with the fracturing angle increasing. Additionally, the thermal fracturing effect of the shale is evaluated under a given scenario. The study is significant for shale oil or gas recovery by in situ pyrolyzing method.INTRODUCTIONOil shale is regarded as a kind of unconventional resource that can contribute to production of shale oil and hydrocarbon gases (Rahm & Dianne, 2011). As is known that there is a large deposit of oil shale in China, and present technology for exploiting oil shale still concentrates on open-pit mining, obtaining shale oil by retorting shale on the ground (Li, Tang, Xue, Zheng, & Du, 2014; Qian, Yin, 2008). However, this technology has a bad effect on the environment and leads to severe resource waste for utilizing oil shale. Exploiting oil shale by in-situ method for ‘green mining’ is widely necessary in China (Kang, Wang, Cao, Liang, Chang, & Liu, 2013; Waters, Dean, Downie, Kerrihard, Austbo, & McPherson, 2009; Zoback, Kohli, Das, & McClure, 2012). One of effective method to exploit shale oil is heating oil shale in-situ underground. For instance, the in-situ conversion process (ICP technique) from Shell Company etc. used a direct heating method, and convectional heating oil shale underground by injecting superheated steam from Mining Technology Institute, Taiyuan University of Technology and constructing horizontal fracture in vertical wellbore from Chevron Company use indirect heating method (Chaudhary, Ehlig, & Wattenbarger, 2011; Hazra, Lee, Economides, & Moridis, 2013; Zhao et al., 2010). The convectional heating method contains complicated procedures with phase transition in double-media of fracture-matrix of oil shale subjected to multi-physical fields coupling including stress, fluid and temperature (Zhao et al., 2010). The characteristics of thermodynamics, solid mechanics and seepage of oil shale have been investigated separately (Hopkins, Rosen, & Hill,1998; Kang, Zhao, & Yang, 2008; Yang, Zhao, Kang, 2010; Zhao, Yang, Feng, Liang, & Kang, 2008; Zhao, Cao, Zhao, Lin, & Wang, 2008). However, it is quite difficult to solve constrained problem of each physical parameter in multi-physical fields coupling for oil shale pyrolysis."

Jan 1, 2015

By Gen Kamimura, Hiroyuki Matsuura

Zinc is widely used for galvanization of steel plates due to its high corrosion resistance. Steel scraps containing waste zinc-coated steel plates are remelted for recycling of steel in electric arc furnace (EAF) process, in which zinc is concentrated in EAF dust ranging from 10 to 40 mass%. Therefore, recycling of zinc from EAF dust is important to secure zinc resource. Our group has proposed selective chlorination and evaporation method recovering zinc as a form of chloride from EAF dust. Since recovered zinc chloride may contain lead, iron and copper as impurities, purification of zinc chloride is essential for production of highly pure metallic zinc. In the present study, removal of lead chloride from molten zinc chloride-alkali chloride by cementation reaction adding zinc was investigated. Experimental results were analyzed and discussed thermodynamically and kinetically as well as the feasibility and limitation of this process were examined.

Mar 1, 2018

By Martin H. Stanczyk

The Organic Act of 1910 established the Bureau of Mines and gave it authority and responsibility for conducting research on separation, recovery, and recycling of waste products and scrap generated by the mineral and metals industries and the consuming public.(1)1 It was apparent to our Nation's leaders even then that mineral resources, once mined, are irreplaceable and that the development of methods for recycling the values contained in wastes would be required to solve the problem of even¬tual scarcity, Estimates of the increase in per capita consumption of mineral resources in this country indicate that the consumption of metals, minerals, and fossil fuels by 1980 will be double that consumed in 1970 (2). The United States can expect to meet its future mineral needs in three basic ways: the first is through increased production of primary raw minerals; second by increasing imports from foreign sources; and third by recycling secondary materials and metals that were formerly discarded as waste. Rather than consider these

Jan 1, 1972

By Roger Storry, Donald Bruce, Arnaud Hochart

"INTRODUCTIONThe Port of Miami Tunnel (POMT), designed and constructed by Bouygues Civil Works Florida between 2009 and 2014, was a Public Private Partnership between the Miami Access Tunnel Concessionaire, Florida Department of Transport, Miami-Dade County and the City of Miami. The project comprises dual 11.3m internal diameter, 1.27km long, twin lane road tunnels running between Watson and Dodge islands and under the main shipping channel in Biscayne Bay (Figure 1).The POMT was a unique project which embodied many technical firsts and involved the first large diameter tunnels constructed through Florida’s challenging sedimentary carbonate strata. At the outset, a comprehensive ground investigation was performed, using both conventional and less conventional investigation techniques, to characterise the highly heterogeneous ground conditions.The findings of the investigation had a major impact on the tunnelling methods, triggering a series of mitigation works to ensure that the tunnels could be excavated safely and effectively. The mitigations included modifications to the already designed Tunnel Boring Machine (TBM), to facilitate an innovative excavation process, and a unique grouting campaign (Storry et. al. 2013a). The project was completed and opened to traffic in August, 2014 and has significantly alleviated traffic congestion in Downtown Miami.GEOLOGICAL CONTEXTThe geological conditions at the project site consist of carbonate sediments which can be divided into distinct geologic units; the Miami Limestone Formation (Layers S3, S4), the Fort Thompson Formation (Layer S5), the Anastasia Formation (Layer S6), the Key Largo Formation (Layer S7) and the Tamiami Formation (Layer S8). Multiple changes in sea level over a relatively short geologic time scale have resulted in a heterogeneous profile consisting of interbedded sedimentary rocks and sediments, which vary widely, both vertically and laterally (Figure 2)."

Jan 1, 2016

By Dana C. Reinke, David K. I Ingram

Researchers at the National Institute for Occupational Safety and Health partnered with the water well industry to develop engi­neering control technologies and training products to address noise exposure at the job site. Noise­induced hearing loss continues to be a problem in the well drilling industry. Research con­ducted by NIOSH found that air rotary drill rigs produce sound levels more than 90 dB(A) over the course of an eight­hour workday. Sounds levels above 90 dB(A), identified during hammer drilling and the hammering of casing, exposes workers to levels that can damage hearing. A typical air rotary drill rig provides no barrier, for noise and dust pro­tection, between the drill’s control panel and the drill stem. The development of a partial cab is the clearest example of NIOSH’s research partnership with the water well industry. NIOSH researchers determined that an engineering noise control to protect the oper­ator at the rig’s control panel would be effective, based on typical work site conditions. Many surface rigs do not have full cabs as a result of the original equipment manufacturer design or the high cost of aftermarket products. Developed as a partial cab, the NIOSH engineer­ing noise control design addressed stakeholders’ needs associated with cost, transport, and worker usage (Figure 1). Field tests found the partial cab effective in reducing sound levels at the rig’s control panel, a typical location for a drill rig operator. Sound levels at the control panel were reduced from 104 to 96 dB(A) (Figure 2). Coupled with continued use of personal protective equipment, such as hear­ing protection devices, the partial cab can help to reduce noise exposure. NIOSH researchers created a CD with informa­tion about noise exposure and the partial cab. Most important to well drilling companies is information on how to construct and attach the partial cab to drill rigs. The CD can be viewed on a standard computer and includes a video of the partial cab in use on a work site. Computer­aided design drawings are included on the CD and provide detail of the cab design as well as information on construction mate­rials and design details. Additionally, the CD provides background infor­mation on noise­induced hearing loss and hearing protection devices to increase knowledge about this occupational health concern. This information can be viewed by all company employees to help promote the partial cab’s importance to workers using the cab. More information on the partial cab noise control technology can be downloaded from www.cdc.gov/ niosh/mining NIOSH researchers also examined the health and safety training needs of workers in the ground water industry. It was quickly realized that most workers learn health and safety on the job and do not attend any sort of formal training. In addition, there is not a lot of time for daily “tailgate talks” or “shop talks” on health and safety issues. As a small business industry, the owner is often operating a drill rig along with his other employees. In general, new employees learn the job in an apprentice style sys­tem. As a result, workers and owners have few opportunities to access uniform health and safety information based upon the job — an outdoor work environment with daily change in work sites. With this information, NIOSH researchers devel­oped two products that deliver health and safety information to fit into the daily work of well drillers. Both are information circulars and are available through download at www.cdc.gov/niosh/mining and the NGWA Web site at www.ngwa.org/publication/ publications.cfm. These circulars are: Water Well Safety Bits. This booklet provides information in a “quick bites” style. It is pre­sented in a magazine format and can be left on

By Liguang Wang, Roe-Hoan Yoon

The thin film balance (TFB) technique was used to measure the equilibrium film thicknesses (H3 between two air bubbles in sodium dodecyl sulfate (SDS) and electrolyte (NaCl) solutions. The results were used to determine the magnitudes of the hydrophobic forces (K232) using the extended DLVO theory. The Km values determined from He measurement allowed us to predict disjoining pressure isotherms, which were found to be in excellent agreement with those obtained experimentally using a bike-wheel film holder. The rate of film thinning was measured at low SDS concentrations with varying amounts of electrolyte (NaCl) added. In general film thinning was controlled by the capillary pressure during the initial stages, while it was controlled by the surfaces forces during the later stages. At low NaCl concentrations, it was possible to predict the rate of film thinning using the Reynolds equation, provided that the driving force was corrected for the contributions from the hydrophobic force, which in turn were determined from the KZ32 values obtained from the He values measured experimentally. At high NaCl concentrations, where it was difficult to measure the equilibrium film thicknesses, the contributions from the hydrophobic forces were determined by fitting the film thinning data to the Reynolds equation. The K232 values obtained using both the equilibrium film thickness and the film thinning measurements showed that hydrophobic force deceased with increasing surfactant and salt concentrations. It was found that the hydrophobic force in foam films was very sensitive to the added electrolyte concentration.

Jan 1, 2005

By D. M. Hausen

A quantitative x-ray diffraction method has been developed for the analysis of alteration minerals in wallrock. Alteration data are plotted and contoured (analogous to geochemical data). Alteration trends outlined by this technique correlate closely with geochemical anomalies, and in some cases attend well beyond the perimeter of anomalous base metal values. "Monomineralic contouring," applied originally to porphyry-type mineralization, has been extended to other types of mineralization, including volcanogenic massive sulfide deposits. Equipment and techniques used in the quantitative measurement of alteration mineralogy are discussed.

Jan 1, 1978

By Paul H. Johnson

A new system for leaching many types of ores has recently been developed on a commercial basis by J and J Research and Development, Inc. of Hanover, New Mexico. This revolutionary new leaching system consists principally of three new leaching reactors; viz, (1) a large, air-agitates, column-like reactor for leaching crushed ores that is constructed in an underground environment and has the inherent ability to do a very efficient job of leaching, (2) a vat-like, air-agitated vessel for leaching an rinsing finely ground ores and , (3) an air-agitated copper precipitation column that is built underground and utilizes an inexpensive dense or heavy scrap iron as a copper precipitant. Each of these new reactors have been used in a large leaching plant near Hanover, New Mexico.

Jan 1, 1973

By Arthur E. Focke

IF a metallurgist employed in an industry producing mechanical parts or assemblies wishes to make the most of his opportunities he will be concerned with every use of metals in that industry. He will not only take part in the testing and treating of the metals used but will assist in their selection and study their behavior in processing and in service. In addition, he will attempt to develop an understanding of the problems involved in the use of the metals in all plant tools and equipment. Metallurgists that follow this course will soon recognize that frequently too little thought is given to the effect of the design of parts on the way the metal in them is expected to behave in service. He will come to realize that changes in the design of a part will often be much more useful than changes in the hardness, strength, composition, or structure of the metals used in them. Does this mean that a metallurgist is out of place in these industries and that he should leave the field to others or be content to fill only a minor role?

Jan 1, 1947

Rotary kiln incinerators are widely used in the incineration of various types of hazardous wastes. However, the complex transport processes within the incinerator are not well understood. Due to large variations in waste types and difficulties in feed characterization, the incineration process meets great challenges in a smooth operation, and expects uncertainties in the process chemistry and emission control. In order to get better understanding of the incineration process, process simulation was made on the kiln behavior by using Computational Fluid-dynamics (CFD) to characterize gas flow, temperature distribution and waste combustion in the incinerator. Temperature measurement was conducted in an operating incinerator to validate the CFD model. This paper addresses the environmental issues related to the hazardous incineration process, and reports the recent simulation results on gas flow and mixing, combustion heat transfer, and potentials to reduce emissions.

Jan 1, 2002

By R. B. Toombs

In describing the Canadian mineral industry in a world setting, this paper examines the industry from four points of view. First, mineral industry growth is related to trends in economic activity thereby providing a measure of the industry's importance in the Canadian economy. To give perspective to the Canadian scene, reference is made to economic trends in several of the world's leading mineral producing and mineral consuming countries. The Canadian mineral industry is next examined in terms of its major developments of the past 20 years and the resultant size, structure, and production diversity of 1964. The position of the Canadian mineral industry in the world industry is then analyzed by tracing changes in mineral supply and demand patterns. Growth of the Canadian industry depends greatly on expansion of export markets because three fifths of the value of production is accounted for by exports. Finally, attention is directed to the outlook for the Canadian mineral industry. Problems facing the industry are surveyed, and an appraisal is made of economic policies that have encouraged industry growth. A forecast of mineral production value in 1970 is included.

Jan 1, 1964

By Jon A. Hummer, Aleksandar D. Bugarski, Shawn Vanderslice, Teresa Barone

A study was conducted to examine the potential of diesel emissions control strategies based on retrofitting existing power packages with exhaust aftertreatment devices and repowering with advanced power packages. The retrofit systems, a diesel oxidation catalyst (DOC) and diesel particulate filter (DPF), were evaluated individually using a US EPA tier 2 (ter 2) engine operated under four steady-state conditions and one transient cycle. The DOC effectively curtailed emissions of CO, and to some extent organic carbon (OC), elemental carbon (EC), and aerosol number concentration. The DPF system offered substantially higher reductions in OC and EC mass and aerosol number concentrations. Both, the DOC and DPF achieved reductions in the aforementioned emissions without adversely affecting emissions of NO2 and nano-sized aerosols. The strategy of repowering with an advanced system was examined using a US EPA tier 4 final (tier 4f) engine equipped with a cooled exhaust gas recirculation system and diesel exhaust fluid-based selective catalytic reduction system, but not with a DPF system. The tier 4f engine contributed substantially less than the tier 2 engine to the EC and OC mass, aerosol number, and CO, NO, and NO2 concentrations. The tier 4f engine was very effective in reducing aerosol mass, NO, and NO2 concentrations, but it was not equally effective in reducing aerosol number concentrations. The implementation of viable exhaust after treatment systems and advanced diesel power packages could be instrumental to the underground mining industry to secure a clean, economical, and dependable source of power for mobile equipment.

By A. Javadi

"Our recent studies revealed that the sulfide minerals in contact with water during grinding produced hydrogen peroxide (H2O2) where the amount of H2O2 production by the minerals found to be in the order of pyrite > chalcopyrite > sphalerite > galena. The H2O2 effect on the oxidation of pulp components and its influence on the concentrate grade and recovery in flotation have been studied and the results have been presented and discussed in this paper. Studies have also been carried out to build correlation between percentage of pyrite in the concentrate, grinding conditions and concentration of OH•/H2O2 in the pulp and as well of controlling the formation of these species through known chemical means for depressing the generation of the oxidant. Flotation tests using a complex sulfide ore with the same reagent scheme that is being used at Bama concentrator in Iran but with the addition i) Na2S reductant and ii) inorganic (EDTA) and organic (TETA) surface modifiers, during grinding stage have been performed to judge the beneficial or detrimental role of H2O2 on the selective flotation of sulfides. The results demonstrate that the selectivity of metal sulfides against pyrite increases with increasing generation of H2O2 in the pulp liquid.INTRODUCTIONOur recent studies have illustrated the formation of hydrogen peroxide (H2O2) by metal-sulphides during grinding in the presence and absence of oxygen (Javadi Nooshabadi & Hanumantha Rao, 2013a; Javadi Nooshabadi & Hanumantha Rao, 2013b; Javadi Nooshabadi & Hanumantha Rao, 2013c; Javadi Nooshabadi & Hanumantha Rao, 2014). In the absence of oxygen, it was found that pyrite surface is catalytically active and able to breakdown water molecules to form OH• free radical and thereby deriving oxygen in the formation of H2O2 from water molecules. The in-situ formation of H2O2 and its influence on sulphide flotation has not been addressed yet. The presence of strong H2O2 oxidant in the pulp liquid and its selective oxidation of pyrite would be beneficial in depressing pyrite flotation. Therefore, it is important to build correlation between percentage of pyrite in the concentrate, grinding conditions and concentration of OH•/H2O2 in the pulp as well as to study possible ways of flexibly controlling the formation of these species through known chemical means for depressing the generation of the oxidant."

Jan 1, 2018