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Catalytic Calcination of Calcium Carbonate

Description: The calcination of calcium carbonate in a cement or a lime kiln uses approximately two to four times the theoretical quantity of energy predicted from thermodynamic calculation depending upon the type of the kiln used (1.4 x 10^6 Btu/ton theoretical to 6 x 10^6 Btu/ton actual). The objective of this research was to attempt to reduce the energy required for the calcination by 1. decreasing the calcination temperature of calcium carbonate, and/or 2. increasing the rate of calcination at a specific temperature. Assuming a catalytic enhancement of 20 percent in the industrial applications, an energy savings of 300 million dollars annually in the United States could be reached in the cement and lime industries. Three classes of compounds to date have shown a positive catalytic effect on the calcination of calcium carbonate. These include alkali halides, phospho- and silico-molybdate complexes, and the fused carbonates system.
Date: August 1985
Creator: Safa, Ali Ibrahim, 1953-
Partner: UNT Libraries

Moisture absorption results for vertical calciner plutonium dioxide product

Description: A sample of calcined plutonium dioxide was exposed to room air for one week. The sample was weighed daily to determine if the material absorbed moisture from the room air. A random variation of weight was observed after the first day; however, the sample returned to its original weight at the end of the week. The loss on ignition for the material increased from 0.439 to 0.544 weight percent during this time. This change is considered inconsequential as the material will normally be packaged for storage within hours of its production.
Date: July 3, 1996
Creator: Compton, J.A., Westinghouse Hanford
Partner: UNT Libraries Government Documents Department

Direct synthesis of LiNi1/3Co1/3Mn1/3O2 from nitrateprecursors

Description: Two novel methods for synthesis of the title compound directly from metal nitrates are described. Phase-pure materials are produced when precursors are calcined between 600 and 1000 C, with little to no ion mixing exhibited for products heated to 900 C or above. The electrochemical characteristics of these materials depended upon calcination temperature and synthesis method, with results comparable to a commercial sample for the materials made at high temperatures in a one-step process without combustion. The sample prepared by combustion also exhibited very stable capacity retention upon cycling.
Date: April 28, 2004
Creator: Patoux, Sebastien & Doeff, Marca M.
Partner: UNT Libraries Government Documents Department


Description: The 15,000 MW nuclear economy assumed for the long range study of pot calcination costs reported earlier was used as a basis for calculating optimum fill volumes. An algebraic expression was developed for cost as a functmon of the normalized radius of the central void space in a partially filled vessel. Minima of this expression were found for acmdmc and neutralized wastes in 6, 12, and 24in.-diameter vessels. Optimum fill volumes decreased as vessel diameter increased, varying for acidic wastes from 99.8% for 6-in.-diameter vessels to 92.5% for 24-in.diameter vessels. Decreases in costs by using optimum fill volumes instead of the 90% fill volume assumed for all cases in the long range study were small, the largest being an 8% decrease for neutralized wastes in 6- in.-diameter vessels. (auth)
Date: November 17, 1961
Creator: Perona, J.J.
Partner: UNT Libraries Government Documents Department

Periodic Waste Disposal System Material Balance Test. Core 1, Seed 2. Test Evaluation T-641317. Section 1

Description: A test was carried out to determine the adequacy of storage capacity and operating procedures of the radioactive waste disposal system during a normal reactor plant warmup. The capacity and operating procedures were found to be adequate. It was impossible to perform a complete material balance based on existing level instrumentation and using the data required by the test procedure. Approximately 21,290 gal. of waste were received in the system and 13,210 gal. were discharged to the river with a total activity of 1200 mu c. A quantity of 6,670 gal. of reactor coolant effluent was processed. Approximately 634 lb of combustible waste were incinerated. (M.C.G.)
Date: June 30, 1961
Partner: UNT Libraries Government Documents Department

Summary of Waste Calcination at INTEC

Description: Fluidized-bed calcination at the Idaho Nuclear Technologies and Engineering Center (INTEC, formally called the Idaho Chemical Processing Plant) has been used to solidify acidic metal nitrate fuel reprocessing and incidental wastes wastes since 1961. A summary of waste calcination in full-scale and pilot plant calciners has been compiled for future reference. It contains feed compositions and operating conditions for all the processing campaigns for the original Waste Calcining Facility (WCF), the New Waste Calcining Facility (NWCF) started up in 1982, and numerous small scale pilot plant tests for various feed types. This summary provides a historical record of calcination at INTEC, and will be useful for evaluating calcinability of future wastes.
Date: October 1, 2000
Creator: O'Brien, Barry Henry & Newby, Bill Joe
Partner: UNT Libraries Government Documents Department

Dry-out and low temperature calcination of DST/SST waste blend high temperature melter feed

Description: The FY1994 DST/SST blend was prepared in accordance with the DST/SST blend feed specification. The laboratory preparation steps and observations were compared with an existing experience base to verify the acceptability of the feed specification for simulant make-up. The most significant test results included a variety of features. Ferrocyanide breaks down to NH{sub 3} plus formate, during the low-temperature calcining phase of the tests. Ferrocyanide displayed no redox reactivity with the nitrates and nitrites contained in the slurry in the absence of sugar. Sugar displays a redox reaction with the nitrates and nitrites in the blend similar to the redox. reaction observed in the LLW feed simulant. Boiling of a free flowing slurry occurs at temperatures below about 120{degrees}C. When about 45% of the total water loss has occurred, the feed slurry congeals and continues to lose water, shrinking and developing shrinkage cracks. Water stops coming off between 350{degrees}C and 400{degrees}C. Slurry shear strength and viscosity strongly increase as the weight percent solids increases from 20 wt% to 45 wt%. The 45 wt% solids corresponds to approximately a 40 % water loss. The principle beat sensitivity for this material is the exothermic reaction which is activated when the temperature exceeds about 250{degrees}C. The breakdown of ferrocyanide to ammonia and formate under strongly basic conditions may begin at temperatures less than 100{degrees}C, but the rate increased strongly with increasing temperature and appeared to be completed in the time of our tests. Differential thermal analysis (DTA) results on feed slurry without and with ferrocyanide showed only endothermic behavior. This is consistent with the dry out and low temperature calcine studies which did not indicate any exothermic behavior for the feed slurry with and without ferrocyanide.
Date: February 1, 1996
Creator: Smith, H.D. & Tracey, E.M.
Partner: UNT Libraries Government Documents Department

Treatment options for low-level radiologically contaminated ORNL filtercake

Description: Water softening sludge (>4000 stored low level contaminated drums; 600 drums per year) generated by the ORNL Process Waste Treatment Plant must be treated, stabilized, and placed in safe storage/disposal. The sludge is primarily CaCO{sub 3} and is contaminated by low levels of {sup 90}Sr and {sup 137}Cs. In this study, microwave sintering and calcination were evaluated for treating the sludge. The microwave melting experiments showed promise: volume reductions were significant (3-5X), and the waste form was durable with glass additives (LiOH, fly ash). A commercial vendor using surrogate has demonstrated a melt mineralization process that yields a dense monolithic waste form with a volume reduction factor (VR) of 7.7. Calcination of the sludge at 850-900 C yielded a VR of 2.5. Compaction at 4500 psi increased the VR to 4.2, but the compressed form is not dimensionally stable. Addition of paraffin helped consolidate fines and yielded a VR of 3.5. In conclusion, microwave melting or another form of vitrification is likely to be the best method; however for immediate implementation, the calculation/compaction/waxing process is viable.
Date: April 1, 1996
Creator: Lee, Hom-Ti & Bostick, W.D.
Partner: UNT Libraries Government Documents Department

Physical property characterization of 183-H Basin sludge

Description: This document describes the characterization of 183-H Basin sludge physical properties, e.g. bulk density of sludge and absorbent, and determination of free liquids. Calcination of crucible-size samples of sludge was also done and the resulting `loss-on-ignition` was compared to the theoretical weight loss based on sludge analysis obtained from Weston Labs.
Date: September 20, 1995
Creator: Biyani, R.K. & Delegard, C.H.
Partner: UNT Libraries Government Documents Department

Simulation and characterization of a Hanford high-level waste slurry

Description: The baseline waste used for this simulant is a blend of wastes from tanks 101-AZ, 102-AZ, 106-C, and 102-AY that have been through water washing. However, the simulant used in this study represents a combination of tank waste slurries and should be viewed as an example of the slurries that might be produced by blending waste from various tanks. It does not imply that this is representative of the actual waste that will be delivered to the privatization contractor(s). This blended waste sludge simulant was analyzed for grain size distribution, theological properties both as a function of concentration and aging, and calcining characteristics. The grain size distribution allows a comparison with actual waste with respect to theological properties. Slurries with similar grain size distributions of the same phases are expected to exhibit similar theological properties. Rheological properties may also change because of changes in the slurry`s particulate supernate chemistry due to aging. Low temperature calcination allows the potential for hazardous gas generation to be investigated.
Date: September 1, 1996
Creator: Russell, R.L. & Smith, H.D.
Partner: UNT Libraries Government Documents Department

CSER 95-005: PFP vertical denitration calciner

Description: The Vertical Denitrating Calciner system will stabilize certain unique solutions containing fissile salts by removing the water and nitrate ion to produce a more easily stored powder. This end is achieved by high-firing the solution in the calciner. The resultant calcine is distinguished by particles which are larger and denser than those produced by the more conventional oxalate precipitation process. This criticality safety evaluation report examines criticality safety for the denitration system, installed in glovebox 188-1 at PFP. The examination shows that, due to the incorporation of standard criticality safety design techniques, the glovebox can be maintained subcritical with minimal reliance on administrative controls. The examination also shows that, ignoring the necessary administrative controls can make a criticality possible in glovebox 188-1. Section 3.0 of this report lists the necessary administrative controls.
Date: May 31, 1995
Creator: Geiger, J.L.
Partner: UNT Libraries Government Documents Department


Description: Progress is reported on research and development work in pot calcination and radiant-heat spray calcination studies of synthetic Purex high-level wastes; and sorption studies using synthetic minerals and resins as well as natural minerals. The calcination studies are discussed in terms of batch calcination, melting of pot calcination products, spray calcination, and off-gas treatment; and sorption studies in terms of mineral reactions, fixation chemistry, and condensate wastes. (B.O.G.)
Date: October 13, 1961
Creator: Irish, E.R. ed.
Partner: UNT Libraries Government Documents Department


Description: Work is being carried out to develop and demonstrate on pilot plant scale integrated processes for treatment and disposal of radmoactive wastes. High-level waste calcination, low-level waste treatment, economic and hazards evaluation, engineering evaluation, disposal in deep wells, disposal in natural salt formations, Clinch River studies, fundamental studies of minerals, and White Oak Creek basin study are discussed. (M.C.G.)
Date: November 29, 1961
Creator: Blanco, R.E. & Struxness, E.G.
Partner: UNT Libraries Government Documents Department


Description: Methods by which the radial deposition mechanism was determined in experiments with simulated waste solutions are reviewed. Based on this mechanism, an expression for the rate of solid deposition with internal heat generation was developed by a combined heat and material balance. A sample calculation for Purex waste showed that a moderate heat generation rate of 5000 Btu/hr/ft/sup 3/ would decrease the time to fill a 12-in.-dia calcination vessel from 78 to 55 hr. For the calcination stage of the process in which the deposited solids are heated in the absence of a liquid phase, a solution was developed for the equation of heat transfer with the temperature profile from the solid deposition stage as an initial condition. For the example Purex waste with a heat generation rate of 5000 Btu/hr ft/sup 3/, less than 15 min would be required for calcination, compared to about 8 hr in experiments with simulated wastes. (auth)
Date: October 23, 1961
Creator: Perona, J.J.
Partner: UNT Libraries Government Documents Department


Description: The costs of pot calcination of Purex and Thorex wastes were calculated. The wastes were assumed produced by a plant processing 1500 ton/year of U converter fuel at a burnup of 10,000 Mwd/ton and 270 ton/year of Th converter fuel at 20,000 Mwd/ton. Costs were calculated for processing Purex waste in acidic and reacidified forms and for processing Thorex wastes in acidic and reacidified forms and with constituents added for producing an acidic Thorex glass. Calcination vessel designs were right circular cylinders similar to those used in engineering development studies. Costs were calculated for processing in 6-, 12-, and 24-in.-dia vessels with a fixed length of 10 ft. Vessel costs used, based on estimates from private industry, were calculated for wastes decayed 120 days and 1, 3, 10, and 30 years after reactor discharge prior to calcination. Aging had negligible effect on costs, except as it permitted larger diameter vessels to be used, because vessel and operating costs were much larger than capital costs in all cases. The lowest cost was 0.87 x 10/sup -2/ mill/kwh/sub e/ for processing acidic Purex and Thorex wastes in 24-in.-dia vessels, and the highest was 5.0 x 10/sup -2/ mill/kwh/sub e/ for processing reacidified Purex and Thorex wastes in 6-in.-dia vessels. About 7 years of interim liquid storage would be required before acidic Purex wastes could be processed in 24-in.-dia vessels. (auth)
Date: October 16, 1961
Creator: Perona, J.J.; Bradshaw, R.L.; Roberts, J.T. & Blomeke, J.O.
Partner: UNT Libraries Government Documents Department

Model Development for the Catalytic Calcination of Calcium Carbonate

Description: Lime is one of the largest manufactured chemicals in the United States. The conversion of calcium carbonate into calcium oxide is an endothermic reaction and requires approximately two to four times the theoretical quantity of energy predicted from thermodynamic analysis. With the skyrocketing costs of fossil fuels, how to decrease the energy consumption in the calcination process has become a very important problem in the lime industry. In the present study, many chemicals including lithium carbonate, sodium carbonate, potassium carbonate, lithium chloride, magnesium chloride, and calcium chloride have been proved to be the catalysts to enhance the calcination rate of calcium carbonate. By mixing these chemicals with pure calcium carbonate, these additives can increase the calcination rate of calcium carbonate at constant temperatures; also, they can complete the calcination of calcium carbonate at relatively low temperatures. As a result, the energy required for the calcination of calcium carbonate can be decreased. The present study has aimed at developing a physical model, which is called the extended shell model, to explain the results of the catalytic calcination. In this model, heat transfer and mass transfer are two main factors used to predict the calcination rate of calcium carbonate. By using the extended shell model, not only the catalytic calcination but also the inhibitive calcination of calcium carbonate have been explained.
Date: December 1987
Creator: Huang, Jin-Mo
Partner: UNT Libraries

Selection of a glass-ceramic formulation to immobilize fluorinel- sodium calcine

Description: One option for immobilizing calcined high level wastes produced by nuclear fuel reprocessing activities at the Idaho Chemical Processing Plant (ICPP) is conversion to a glass-ceramic form through hot isostatic pressing. Calcines exist in several different chemical compositions, and thus candidate formulations have been developed for converting each to glass-ceramic forms which are potentially resistant to aqueous corrosion and stable enough to qualify for repository storage. Fluorinel/Na, a chemically complex calcine type, is one of the types being stored at ICPP, and development efforts have identified three formulations with potential for immobilizing it. These are a glass forming additive that uses aluminum metal to enhance reactivity, a second glass forming additive that uses titanium metal to enhance reactivity and a third that uses not only a combination of silicon and titanium metals but enough phosphorous pentoxide to form a calcium phosphate host phase in the glass-ceramic product. Glass-ceramics of each formulation performed well in restricted characterization tests. However, none of the three was subjected to rigorous testing that would provide information on whether each was processable, that is able to retain favorable characteristics over a practical range of processing conditions.
Date: December 1, 1994
Creator: Staples, B.A. & Wood, H.C.
Partner: UNT Libraries Government Documents Department


Description: An over-all description of the background material on the use of electrical arcs for heating of powders is presented as well as a summary of experimental studies on the arc calcination of thoria. Favorable results have been indicated both with heating thoria powder in an arc heated gas and with thoria formed into a consumable electrode. Use of a consumable electrode produces thoria particles 0.1 to 0.01 mu in diameter. It is recommended that additional electrodes be fabricated and further arc calcination tests be run to produce a quantity of product sufficient for evaluation. (auth)
Date: June 25, 1958
Creator: Johnsson, K.O.
Partner: UNT Libraries Government Documents Department

Preparation of Americium Dioxide by Thermal Decomposition of Americium Oxalate in Air

Description: One hundred and seventy five grams of americium in a hydrochloric acid solution varying from 1 to 7 N was converted to americium dioxide. Americium oxalate was precipitated from 0.1 N HCI with 100% excess oxalic acid and was converted to the dioxide by calcination at 800 ts C in air. The solubility losses in the oxalate precipitation filtrate averaged approximately 7 mg/liter of solution, with a total loss of 0.09%. (auth)
Date: December 20, 1960
Creator: Baybarz, R. D.
Partner: UNT Libraries Government Documents Department

Controlled Assembly of Heterobinuclear Sites on Mesoporous Silica: Visible Light Charge-Transfer Units with Selectable Redox Properties

Description: Mild synthetic methods are demonstrated for the selective assembly of oxo-bridged heterobinuclear units of the type TiOCrIII, TiOCoII, and TiOCeIII on mesoporous silica support MCM-41. One method takes advantage of the higher acidity and, hence, higher reactivity of titanol compared to silanol OH groups towards CeIII or CoII precursor. The procedure avoids the customary use of strong base. The controlled assembly of the TiOCr system exploits the selective redox reactivity of one metal towards another (TiIII precursor reacting with anchored CrVI centers). The observed selectivity for linking a metal precursor to an already anchored partner versus formation of isolated centers ranges from a factor of six (TiOCe) to complete (TiOCr, TiOCo). Evidence for oxo bridges and determination of the coordination environment of each metal centers is based on K-edge EXAFS (TiOCr), L-edge absorption spectroscopy (Ce), and XANES measurements (Co, Cr). EPR, optical, FT-Raman and FT-IR spectroscopy furnish additional details on oxidation state and coordination environment of donor and acceptor metal centers. In the case of TiOCr, the integrity of the anchored group upon calcination (350 oC) and cycling of the Cr oxidation state is demonstrated. The binuclear units possess metal-to-metal charge-transfer transitions that absorb deep in the visible region. The flexible synthetic method for assembling the units opens up the use of visible light charge transfer pumps featuring donor or acceptor metals with selectable redox potential.
Date: June 4, 2008
Creator: Frei, Heinz; Han, Hongxian & Frei, Heinz
Partner: UNT Libraries Government Documents Department

Optimization of Carbon Coatings on LiFePO4

Description: The electrochemical performance of LiFePO{sub 4} in lithium cells is strongly dependent on the structure (disordered/graphene or D/G ratio) of the in situ carbon produced during synthesis from carbon-containing precursors. Addition of pyromellitic acid (PA) prior to final calcination results in lower D/G ratios, yielding a higher-rate material. Further, improvements in electrochemical performance are realized when graphitization catalysts such as ferrocene are also added during LiFePO{sub 4} preparation, although overall carbon content is still less than 2 wt.%.
Date: July 14, 2005
Creator: Doeff, Marca M.; Wilcox, James D.; Kostecki, Robert & Lau, Grace
Partner: UNT Libraries Government Documents Department


Description: The literature has been reviewed in December 2011 for calcination data of plutonium oxide (PuO{sub 2}) from plutonium oxalate Pu(C{sub 2}O{sub 4}){sub 2} precipitation with respect to the PuO{sub 2} specific surface area (SSA). A summary of the literature is presented for what are believed to be the dominant factors influencing SSA, the calcination temperature and time. The PuO{sub 2} from Pu(C{sub 2}O{sub 4}){sub 2} calcination data from this review has been regressed to better understand the influence of calcination temperature and time on SSA. Based on this literature review data set, calcination temperature has a bigger impact on SSA versus time. However, there is still some variance in this data set that may be reflecting differences in the plutonium oxalate preparation or different calcination techniques. It is evident from this review that additional calcination temperature and time data for PuO{sub 2} from Pu(C{sub 2}O{sub 4}){sub 2} needs to be collected and evaluated to better define the relationship. The existing data set has a lot of calcination times that are about 2 hours and therefore may be underestimating the impact of heating time on SSA. SRNL recommends that more calcination temperature and time data for PuO{sub 2} from Pu(C{sub 2}O{sub 4}){sub 2} be collected and this literature review data set be augmented to better refine the relationship between PuO{sub 2} SSA and its calcination parameters.
Date: March 6, 2012
Creator: Daniel, G.
Partner: UNT Libraries Government Documents Department

Effects of stabilization temperature on surface area and grain size of representative plutonium materials.

Description: Calcination at 400-1000C is used throughout the Department of Energy (DOE) complex to stabilize plutonium material for transportation and storage . The objectives of this stabilization are to remove moisture and other potentially water-producing phases, and to ensure that readsorption will not occur before material is placed in welded containers .Such moisture may threaten the integrity of containers through pressurization with radiolytically generated hydrogen. It is also considered valuable to reduce the fine (respirable) fraction of the material to mitigate potential impact of accidents.
Date: January 1, 2003
Creator: Boak, J. M. (Jeremy M.); Dale, D. J. (Deborah J.) & Eller, P. G. (Phillip Gary)
Partner: UNT Libraries Government Documents Department