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Problems in the Firing of Refractories

Description: From Introduction: "In large measure the work was an outgrowth of that done by the bureau in the investigation of burning problems for Four Heavy Clay Products Associations."
Date: 1927
Creator: Bole, G. A.; Blizard, John; Rice, W. E.; Ogden, E. P. & Sherman, R. A.
Partner: UNT Libraries Government Documents Department

A Study of Refractories Service Conditions in Boiler Furnaces

Description: From Scope of Report: "The findings of the preliminary survey are first briefly presented; these are followed by a general description of the furnaces and fuels investigated. A chapter follows on each of the four conditions of service studied: (1) The temperature and composition of the furnace gases, (2) the velocity of the furnace gases, (3) the temperature of the refractories, and (4) the composition and characteristics of boiler-furnace slags. In each chapter the significance of the condition of service, the factors that govern it, the method of investigation, representative data from the installations, and a comparative summary are given."
Date: 1931
Creator: Sherman, Ralph A.
Partner: UNT Libraries Government Documents Department


Description: The U--Zr phase diagram is presented. Melting points of B and other oxides ahove 2000 deg C were determined. The structure of Ca and Sr aluminates was refined, and Al/sub 2/)/sub 3/UO/sub 2/ bodies were fabricated. Techniques for impregnating leached unfired Vycor are being standardized. The effects of radiation on hardness of Vycor and on Pu-- U oxides have been obtained. (C.H.)
Date: October 31, 1958
Creator: Bruch, C.A. & Cashin, W.M.
Partner: UNT Libraries Government Documents Department

An Assessment of Recycled Refractory Material Performance After Two Years of Service in a Carbon Bake Furnace

Description: Material removed from carbon bake furnaces used to manufacture anodes for the production of aluminum metal has historically been disposed by landfill. This material is composed primarily of 50% alumina refractory. in 1997, Alcoa completed a highly successful program to reuse the spent refractories in castables for carbon bake furnace headwalls and flooring, as roadbed aggregate, and in other internal applications. This program recycled/reused 11,000 metric tons of used refractory material (99% of the material removed from the carbon bake furnace) and saved Alcoa over 3.8 of the 9.6 million dollar projected furnace rebuild costs. As assessment is made of the performance of the recycled refractory components after two years of service.
Date: October 27, 1999
Creator: Schubert, N.; Bennett, J.P. & Kwong, K.S.
Partner: UNT Libraries Government Documents Department

Toxic Characteristic Leaching Procedure (TCLP) Testing of Waste Glass and K-3 Refractory

Description: The U. S. Environmental Protection Agency (EPA) issued revised Resource Conservation and Recovery Act (RCRA) Phase IV Land Disposal Restrictions (LDR's) on May 26 1998. The new regulation requires that any waste characteristically hazardous for the metals As, Ba, Cd, Cr, Pb, Hg, Se, and Ag will have to be treated to meet the LDR Universal Treatment Standards (UTS) for each metal prior to land disposal. Since EPA regulations continue to become more stringent, here-to-fore unpublished TCLP data generated during testing of simulated High Level Waste (HLW) glass, including the Evnironmental Assessment glass and K-3 melter refractory, will be reviewed. The refractory TCLP data compilation includes K-3 refractory in contact with DWPF simulated glass in a pilot scale melter and K-3 refractory in contact with actual mixed waste glass in a 5 ton a day GTS Duratek melter.
Date: April 23, 1999
Creator: Jantzen, C.M.
Partner: UNT Libraries Government Documents Department

Fusion Techniques for the Oxidation of Refractory Actinide Oxides

Description: Small-scale experiments were performed to demonstrate the feasibility of fusing refractory actinide oxides with a series of materials commonly used to decompose minerals, glasses, and other refractories as a pretreatment to dissolution and subsequent recovery operations. In these experiments, 1-2 g of plutonium or neptunium oxide (PuO<sub>2</sub> or NpO<sub>2</sub>) were calcined at 900 degrees Celsius, mixed and heated with the fusing reagent(s), and dissolved. For refractory PuO<sub>2</sub>, the most effective material tested was a lithium carbonate (Li<sub>2</sub>CO<sub>3</sub>)/sodium tetraborate (Na<sub>2</sub>B<sub>4</sub>O<sub>7</sub>) mixture which aided in the recovery of 90 percent of the plutonium. The fused product was identified as a lithium plutonate (Li<sub>3</sub>PuO<sub>4</sub>) by x-ray diffraction. The use of a Li<sub>2</sub>CO<sub>3</sub>/Na<sub>2</sub>B<sub>4</sub>O<sub>7</sub> mixture to solubilize high-fired NpO<sub>2</sub> was not as effective as demonstrated for refractory PuO<sub>2</sub>. In a small-scale experiment, 25 percent of the NpO<sub>2</sub> was oxidized to a neptunium (VI) species that dissolved in nitric acid. The remaining neptunium was then easily recovered from the residue by fusing with sodium peroxide (Na<sub>2</sub>O<sub>2</sub>). Approximately 70 percent of the neptunium dissolved in water to yield a basic solution of neptunium (VII). The remainder was recovered as a neptunium (VI) solution by dissolving the residue in 8M nitric acid. In subsequent experiments with Na<sub>2</sub>O<sub>2</sub>, the ratio of neptunium (VII) to (VI) was shown to be a function of the fusion temperature, with higher temperatures (greater than approximately 400 degrees C) favoring the formation of neptunium (VII). The fusion of an actual plutonium-containing residue with Na<sub>2</sub>O<sub>2</sub> and subsequent dissolution was performed to demonstrate the feasibility of a pretreatment process on a larger scale. Sodium peroxide was chosen due to the potential of achieving higher actinide recoveries from refractory materials. In this experiment, nominally 10 g of a graphite-containing residue generated during plutonium casting operations was initially calcined to remove the graphite. Removal of combustible material prior ...
Date: April 15, 1999
Creator: Rudisill, T.S.
Partner: UNT Libraries Government Documents Department

Lightweight alumina refractory aggregate. Phase 2, Pilot scale development

Description: Kilogram quantities of refractory aggregate were prepared from both a paste and a pelletized form of extruder feed material in both bench and pilot-scale equipment. The 99{sup +} % alumina aggregate exhibited a bulk density approaching 2.5 g/cm{sup 3} and a fired strength slightly lower than fused alumina. Based on initial evaluation by two refractory manufacturers in brick or castable applications, the new aggregate offered adequate strength with thermal conductivity reductions up to 34%, depending on the temperature and application of the new aggregate in these initial trials. The new aggregate was simply substituted for Tabular{trademark} in the refractory formulation. Thus, there is room for improvement through formulation optimization with the lightweight aggregate. The new aggregate offers a unique combination of density, strength, and thermal properties not available in current aggregate. To this point in time, technical development has led to a pelletized formulation with borderline physical form leaving the Eirich mixer. The formulation requires further development to provide more latitude for the production of pelletized material without forming paste, while still reducing the bulk density slightly to reach the 2.5 g/cm{sup 3} target. The preferred, pelletized process flowsheet was outlined and a preliminary economic feasibility study performed based on a process retrofit into Alcoa`s Arkansas tabular production facilities. Based on an assumed market demand of 20,000 mt/year and an assumed selling price of $0.65/lb (25% more than the current selling price of Tabular{trademark}, on a volume basis), economics were favorable. Decision on whether to proceed into Phase 3 (full- scale demonstration) will be based on a formal market survey in 1994 October.
Date: November 1, 1994
Creator: Swansiger, T.G. & Pearson, A.
Partner: UNT Libraries Government Documents Department

Monitoring of Refractory Wall recession using high temperature impact echo instrumentation

Description: Regression of refractory linings of furnaces occurs due to a variety of mechanisms. The specific mechanism selected for investigation during this program is the regression of refractories which are in direct contact with a liquid corrodant. Examples include the melting of glass, the production of pig iron and steel, and the melting of aluminum. The rates of regression to a wall thickness which requires reline or extensive reconstruction vary widely, from less than a year to over ten years depending on the specific service environment. This program investigated the feasibility of measuring refractory wall thickness with an impact-echo method while at operating temperature (wall temperatures exceeding 500 C). The impact-echo method uses the impact of a small sphere with the surface of the test object to send a stress wave into the object. In a plate-like structure, the stress wave reflects back to the front surface, reverberating in the structure and causing a periodic surface displacement whose frequency is inversely proportional to the thickness of the test object. Impact-echo testing was chosen because it requires access to only one side of the test object and could be performed during the operation of a refractory structure. Commercially-available impact-echo instrumentation is available for room temperature use for a variety of tests on concrete. The enabling technology for this work was to use a high-temperature piezoelectric material, aluminum nitride, as the receiving sensor for the stress waves, allowing its use on refractories during furnace operation.
Date: April 30, 2004
Creator: Dayton, University of
Partner: UNT Libraries Government Documents Department

Project B: Improved Liquid Steel Feed For Slab Casters

Description: This report describes the completion of the development of an electromagnetic valve to control liquid steel flow for improved liquid steel feeding for slab casters. Achievements result from a joint research effort between Westinghouse Science and Technology Center, North American Refractories and U.S. Steel. This effort is part of the American Iron and Steel Institute's (AISI) Advanced Process Control Program, a collaboration between the U.S. Department of Energy (DOE) and fifteen North American steel makers.
Date: October 1, 1998
Creator: Isaacson, Brent S.; Slepian, Mike & Richter, Thomas
Partner: UNT Libraries Government Documents Department

Ceramic subsurface marker prototypes

Description: The client submitted 5 sets of porcelain and stoneware subsurface (radioactive site) marker prototypes (31 markers each set). The following were determined: compressive strength, thermal shock resistance, thermal crazing resistance, alkali resistance, color retention, and chemical resistance.
Date: May 2, 1985
Creator: Lukens, C. E.
Partner: UNT Libraries Government Documents Department

Field Trial Results of an Improved Refractory Material for Slagging Gasifiers

Description: Gasifiers are used commercially to react a carbon feedstock with water and oxygen under reducing conditions; producing chemicals used as feedstock for other processes, fuel for power plants, and/or steam used in other processes. A gasifier acts as a high temperature, high pressure reaction chamber, typically operating between 1250-1575°C, and with pressures between 300-1000 psi. Ash that originates from mineral impurities in the carbon feedstock becomes a by-product of gasification. In a slagging gasifier it melts, forming a liquid which flows down the gasifier sidewall; penetrating and wearing away the refractory liner by corrosive dissolution, abrasive wear, or by other processes such as spalling. The refractory liner must withstand the severe service environment, protecting the steel shell against corrosive gases, temperature, and material wear. Users have identified refractory service life as the most important limitation to sustained on-line availability of gasifiers, limiting gasifier acceptance and use by industry. The National Energy Technology Laboratory in Albany, OR, has developed and patented (US Patent # 6,815,386) a phosphate containing high chrome oxide refractory for use in slagging gasifiers. In cooperation with ANH Refractories Company, this refractory material has been commercially produced and is undergoing field tests in commercial gasifiers. An analysis of data from these field tests indicates that the phosphate containing refractory results in an improved service life over other refractory materials currently used as gasifier liners. Results from the post-mortem analysis of the field trial in relation to the failure mechanisms in a slagging gasifier will be presented.
Date: September 1, 2006
Creator: Bennett, J. P.; Kwong, K.-S.; Powell, C. P.; Petty, A. V., Jr.; Thomas, H.; Prior, H. D. et al.
Partner: UNT Libraries Government Documents Department

An update on the development of an improved performance refractory material for slagging coal gasifiers

Description: Severe slag attack of high temperature materials that line coal gasifiers used in the production of chemicals, liquid fuels, and/or electricity result in their unacceptably short lifetimes, lasting anywhere from 3 months to 24 months. Lengthening of this short service life to increase gasifier reliability and increase on-line availability of a gasifier is viewed as critical for greater technology acceptance and utilization. A phosphate containing high chrome oxide refractory has been developed by the Albany Research Center of DOE and scaled up by an industrial producer of refractories for plant trials. An update of this material and its properties will be presented.
Date: January 1, 2004
Creator: Powell, Cynthia A.; Kwong, Kyei-Sing; Bennett, James P. & Chinn, Richard E.
Partner: UNT Libraries Government Documents Department

Engineered refractoriers for slagging coal gasifiers

Description: The widespread commercial adaptation of slagging gasifier technology to produce power, fuel, and/or chemicals from coal will depend in large measure on the technology's ability to prove itself both economic and reliable. Improvements in gasifier reliability, availability, and maintainability will in part depend on the development of improved structural materials with longer service life in this application. Current generation refractory materials used to line the gasifier vessel, and contain the gasification reaction, often last no more than three to 18 months in commercial applications. The downtime required for tear-out and replacement of these critical materials results in gasifier on-line availabilities that fall short of targeted goals. In this talk we will discuss the development of improved refractory materials engineered specifically for longer service life in this application, with emphasis on the design of new refractories that contain little or no chrome.
Date: January 1, 2005
Creator: Bennett, James P.; Kwong, Kyei-Sing; Powell, Cynthia A; Krabbe, Rick & Thomas, Hugh
Partner: UNT Libraries Government Documents Department

Sintering of polycrystalline ionic conductors:. beta. &#x27;&#x27;-Al/sub 2/O/sub 3/ and NASICON

Description: The densification kinetics for both ..beta..&#x27;&#x27;-alumina and NASICON are dramatically different. ..beta..&#x27;&#x27;-Alumina sinters by a reactive liquid process whereas NASICON densifies by a solid state method. More importantly, a qualitative examination of particle and agglomerate distributions, phase composition, linear shrinkage analysis, and heating rate effects can result in a concise determination of sintering processes without recourse to more quantitative techniques. Such a simple procedural method should be a basis for any beginning investigative study into the densification mechanism of new multicomponent ceramic materials.
Date: January 1, 1979
Creator: McEntire, B J; Miller, G R & Gordon, R S
Partner: UNT Libraries Government Documents Department

Development of high performance refractory fibers with enhanced insulating properties and longer service lifetimes: Phase 2, Improved refractory fiber and industrial benefit development. Final report

Description: This is Phase II of a three-phase study for the development of high performance refractory fibers with enhanced insulating properties and longer service lifetimes, for use in the aluminum, glass, cement, and iron and steel industries. Fiberization of 24 out of 25 compositions in the Al{sub 2}O{sub 3}-Si0{sub 2}-Zr0{sub 2} system were achieved. These 24 and three existing fiber compositions were evaluated: The shrinkage and the crystalline and vitreous phases were determined vs heat treatment time and temperature. Four theoretical models were developed: Shrinkage, devitrification kinetics, density change, and fiberization. Although some of the fibers formed during Phase II had properties as good as the reference ASZ fiber, no fiber had a significantly improved performance. This work, although not entirely successful, did produce significant benefits to refractory insulating fiber manufacturers and users: Mechanisms of both linear and thickness shrinkage for vitreous refractory fibers were determined, devitrification kinetics were quantified and used in models to predict shrinkage during service, and the mechanism of fiber formation in the melt spinning process was studied.
Date: May 1, 1995
Creator: Cai, Yifang; Curtis, J.M.; DePoorter, G.L.; Martin, P.C. & Munoz, D.R.
Partner: UNT Libraries Government Documents Department

Compressive Creep Performance and High Temperature Dimensional Stability of Conventional Silica Refractories

Description: Furnace designers and refractory engineers recognize that optimized furnace superstructure design and refractory selection are needed as glass production furnaces are continually striving toward greater output and efficiencies. Harsher operating conditions test refractories to the limit, while changing production technology (such as the conversion to oxy-fuel from traditional air-fuel firing) can alter the way the materials perform. Refractories for both oxy- and air-fuel fired furnace superstructures are subjected to high temperatures during service that may cause them to excessively creep or subside if the refractory material is not creep resistant, or if it is subjected to high stress, or both. Furnace designers can ensure that superstructure structural integrity is maintained if the creep behavior of the refractory material is well understood and well represented by appropriate engineering creep models. Several issues limit the abilities of furnace designers to (1) choose the optimum refractory for their applications, (2) optimize the engineering design, or (3) predict the service mechanical integrity of their furnace superstructures. Published engineering creep data are essentially non-existent for almost all commercially available refractories used for glass furnace superstructures. The limited data that do exist are supplied by the various refractory suppliers. Unfortunately, these suppliers generally have different ways of conducting their mechanical testing and they also interpret and report their data differently; this makes it hard for furnace designers to draw fair comparisons between competing grades of candidate refractories. Furthermore, the refractory supplier's data are often not available in a form that can be readily used for furnace design and for the prediction and design of long-term structural integrity of furnace superstructures. With the aim of providing such comparable data, the US DOE's Office of Industrial Technology and its Advanced Industrial Materials program is sponsoring work to conduct creep testing and analysis on refractories of interest to the ...
Date: March 1, 1999
Creator: Karakus, M.; Kirkland, T.P.; Liu, K.C.; Moore, R.E.; Pint, B.A. & Wereszczak, A.A.
Partner: UNT Libraries Government Documents Department

Kinetics of refractory fiber glass devitrification

Description: The kinetic model of Johnson-Mehl-Avrami was successfully applied to the devitrification of two alumina-silica based refractory glass fibers during the period of single phase crystallization. The volume fraction crystallized was found as a function of time and temperature. Linear shrinkage in a fiber was calculated as a function of volume fraction crystallized. This allows the practical prediction of performance of a fiber based on linear shrinkage at the actual use temperature.
Date: December 31, 1995
Creator: Curtis, J.M. & DePoorter, G.L.
Partner: UNT Libraries Government Documents Department

Characterization and bulk properties of oxides

Description: The bulk properties of oxides are divided into two classes, intrinsic properties which depend solely on the identity of the material, and extrinsic ones, which differ for different samples of the same compound. Sources of tabulated numerical values of intrinsic properties are given and modern developments in information storage and retrieval are discussed. Extrinsic properties are shown to depend on defects and trace impurities in the samples. Techniques of trace impurity analysis are discussed and realistic limits of detection and accuracies are given for routine analyses.
Date: June 1, 1979
Creator: Sonder, E & Connolly, T F
Partner: UNT Libraries Government Documents Department

High Temperature Materials Laboratory third annual report

Description: The High Temperature Materials Laboratory has completed its third year of operation as a designated DOE User Facility at the Oak Ridge National Laboratory. Growth of the user program is evidenced by the number of outside institutions who have executed user agreements since the facility began operation in 1987. A total of 88 nonproprietary agreements (40 university and 48 industry) and 20 proprietary agreements (1 university, 19 industry) are now in effect. Sixty-eight nonproprietary research proposals (39 from university, 28 from industry, and 1 other government facility) and 8 proprietary proposals were considered during this reporting period. Research projects active in FY 1990 are summarized.
Date: December 1, 1990
Creator: Tennery, V.J. & Foust, F.M.
Partner: UNT Libraries Government Documents Department


Description: The thermodynamic properties of refractory borides, carbides, nitrides, and oxides of some 31 elements are compiled. Several tables for elements and compounds not previously reported are presented, and the experimental spectroscopic studies of the vapor of boron oxide and hydroxide are discussed. (R.J.S.)
Date: December 15, 1962
Creator: Schick, H.L.; Anthrop, D.F.; Dreikorn, R.E.; Feber, R.C.; Hanst, P.L.; Panish, M.B. et al.
Partner: UNT Libraries Government Documents Department

Surface selective membranes for carbon dioxide separation

Description: In this study, hybrid membranes have been developed for the selective separation of CO2 from mixtures containing H2. Beginning with commercially available Pall alumina membrane tubes with nominal pore diameter of 5 nm, hybrids were produced by silation with a variety of functionalities designed to facilitate the selective adsorption of CO2 onto the pore surface. The goal is to produce a membrane which can harness the power of surface diffusion to give the selectivity of polymer membranes with the permeance of inorganic membranes.
Date: September 1, 2005
Creator: Luebke, D.R.; Pennline, H.W. & Myers, C.R.
Partner: UNT Libraries Government Documents Department