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At least 217 records · Page 12
All sourcesNASA NTRSDOE OSTI
DOE OSTI2020

Low-Temperature Plasma Treatment for Enhanced Recovery of Highly Valued Critical REEs from Coal (Final Report)

The principle objective of this project was to develop a novel process flowsheet using low-temperature plasma treatment (LTP) integrated with conventional hydrometallurgical processes to recover rare earth elements (REEs), especially highly valued REEs (i.e. scandium and critical REEs), from coal and coal byproducts. LTP treatment was used to pretreat the solid feed material prior to leaching in an effort to improve the leaching characteristics of the REEs and potentially reduce acid consumption. Initially, a detailed experimental program was performed on a laboratory LTP furnace to identify a set of process parameter values to be used for assessing the enhanced leaching performance achieved on four specific gravity fractions of West Kentucky No. 13 and Fire Clay coarse coal refuse materials. High-temperature oxidation (HTO)) was also evaluated as a means for improving REE leachability on the same fractions of both coal sources. The lixiviants used to assess leachability improvements included: i) untreated water, ii) 0.1 M ammonium sulfate solution and iii) 1.2 M sulfuric acid solution at a temperature of 75°C. The laboratory data was used to develop multiple process flow sheets using HTO only to produce a rare earth oxide mix concentrate or utilizing both LTP and HTO treatment processes to generate a high purity heavy REO mix concentrate and a light REO mix concentrate. A techno-economic analysis was performed on each circuit. Low-temperature plasma oxidation was found to enhance REE leaching characteristics for all specific gravity (SG) fractions of the West Kentucky No. 13 coarse refuse material. The leaching recovery improvement was preferentially achieved for the heavy REEs with higher values obtained when treating the lower density fraction material. For example, the leaching recovery for the heavy REEs in the untreated 1.6 SG Float fraction material was 8% in a 0.1 M ammonium sulfate solution. After LTP treatment for 32 hours, heavy REE recovery increased to 33%. The corresponding recovery value for the light REEs was 10%. These findings indicate a strong affinity of the heavy REEs with the organic material, which is the component being reduced in content during the LTP treatment. Scanning electron micrographs showed the development of a honeycomb structure with increased LTP treatment with higher surface area as confirmed from BET measurements. Higher surface area promotes improved leaching efficiency due to enhance chemical interactions. When using 1.2 M sulfuric acid, the LTP treatment was found to provide a heavy REE recovery increase from 23% to 53% for the 1.6 SG Float fraction which corresponded to an ash content increase from around 20% to 35%. However, LTP treatment provided no improvement in leaching characteristic for the 2.2 SG sink material in the acid solution, which was likely due to the low organic content. The LTP treatment of the Fire Clay SG fractions provided no improvement in REE leaching characteristic, which may be due to the association with REE minerals such as monazite and REE-associated mineral matter such as clays. High temperature oxidation using temperatures in the range of 600-750OC was found to significantly enhance the leaching characteristics of both the light and heavy REEs for all density fractions in both coarse coal refuse materials. Generally, the increase in light REE recovery for the West Kentucky material was from 15% for the untreated material to 90% for the HTO treated material at 600°C. Recovery values dropped significantly when using temperatures below 600°C and above 750°C. The impact of the excessive temperatures was most likely a result of sintering. For the heavy REEs, HTO significantly improved recovery in the lighter SG fractions, which may be due to an affinity with the organic content. Only limited heavy REE recovery improvement was obtained for the denser SG fractions. Another benefit of HTO is the conversion of calcium-based minerals to a very soluble calcium oxide, which is removable using a mild acid solution, and the conversion of Fe minerals to relatively insoluble minerals such as hematite and magnetite. The pregnant leaching solution produced from the leaching of all SG fractions obtained from both coal sources was treated using two stages of solvent extraction procedurally modeling a rougher-cleaner circuit followed by oxalic acid precipitation. Rare earth oxide products having a purity greater than 97% was produced from nearly all of the SG fractions. A novel process flowsheet was developed based on the selective leaching of heavy REEs that was made possible through LTP treatment of West Kentucky No. 13 coarse refuse followed by salt leaching. In the flowsheet, coal refuse material is ground to a top size of 1mm and then treated by LTP. The treated material is mixed into a 0.1 M ammonium sulfate solution and then filtered to produce a heavy REE enriched pregnant leach solution. The heavy REEs are concentrated by two stages of selective precipitation to produce a heavy REE mix oxalate and then roasted to obtain a heavy REO mix concentrate. The solid residues remaining after salt leaching is dried and then subjected to HTO treatment followed by concentration using selective precipitation and roasting to produce a light REO mix concentrate. An alternative circuit was developed using HTO treatment only to treat 100% of the coarse refuse material followed by selective precipitation and roasting to generate a high purity REO mix product. A techno-economic analysis performed for the treatment of West Kentucky No. 13 and Fire Clay coarse refuse based on a hypothetical 500-tph plant revealed that the net present value for all scenarios was significantly negative. Primary reasons include: i) a substantial decrease in the basket value of the final product relative to the feed and ii) high chemical costs relative to the amount of product generated. The basket value reduction was primarily due to little to no scandium recovery due to poor leaching characteristics when using low acid concentrations as necessitated by the low feed grades. Operating costs were primarily influenced by the chemical costs relative to the kilograms of concentrate produced and feed grade. For the Fire Clay coarse refuse material, the total operating cost was estimated to be $354 per kg of REO produced which was higher than the basket value of the REO product ($276/kg). Approximately 37% of the total cost was the sulfuric acid used during the leaching process. A comparative analysis performed to assess the economic viability of using low-temperature plasma furnaces found that market value enhancement for the generation of both heavy REO and light REO concentrates will be needed in addition to significant technology advancements to reduce the cost of plasma furnaces.

01 COAL, LIGNITE, AND PEAT↗
NASA NTRS1984

The atmospheric effects of El Chichon

The eruption of the Mexican volcano El Chichon in late March and early April of 1982 injected an unusually large amount of volcanic material into the stratosphere. This event demonstrates for the first time that a relatively small but sulfur-rich volcanic eruption can produce a dense, widespread stratospheric cloud. Sulfuric acid aerosol is formed by the photochemical reaction of sulfur gases released by a volcano with water vapor in the atmosphere. The aerosol causes a decrease in the mean global temperature because the droplets both absorb solar radiation and scatter it back into space. Attention is given to details concerning the volcanic eruption, the relation of El Chichon to the Mexican and Guatemalan volcanic belts, sources for the sulfur erupted by the volcano, and the mechanisms involved in the formation of sulfuric acid.

Rampino, M. R.↗
DOE OSTI2023

Parametric study of an acid baking process for rare earth element recovery from a bituminous-coal source

Acid baking treatment is widely used to extract rare earth elements (REEs) from refractory rare earth bearing minerals such as monazite and xenotime. Since these REE minerals have been identified in coal-based sources, a parametric study was conducted to evaluate the impact and optimize the parametric values associated with the acid-baking process when treating a bituminous coal source. The parameters studied using a three-level statistical experimental program were acid baking time, acid solution concentration, baking temperature, and acid solution-to-solids ratio and each were found to significantly impact REE and contaminant element recovery. An increase in baking temperature up to around 250°C improved the light and heavy REE recovery values by more than 50 absolute percentage points relative to performances achieved when direct leaching. Acid baking was needed to dehydroxylate the clays and liberate the REE minerals, which allowed access for the acid to solubilize the REEs. Acid concentration of the solution used for acid baking was studied as a means of minimizing the amount of acid needed to achieve a target REE recovery. However, thermo-gravimetric and differential scanning calorimetry analysis (TGA-DSC) of sulfuric acid under oxidizing atmosphere revealed that the addition of water decreased the evaporation temperature, which explains the lower REE recovery values obtained when using lower acid concentrations. Using pure sulfuric acid at an acid-to-solid ratio of 0.8:1 resulted in recovery values of around 70% for both LREEs and HREEs. The decomposition reaction time was relatively quick with 65% of the TREEs recovered within the first 10 minutes. Water leaching experiments performed on the acid-baked products under a temperature of 25°C instead of 75°C revealed an increase in REE recovery by 10 absolute percentage points, which was likely due to the high solubility of REE-sulfates at room temperatures.

01 COAL, LIGNITE, AND PEAT↗
NASA NTRS2006

Laboratory Simulated Acid-Sulfate Weathering of Basaltic Materials: Implications for Formation of Sulfates at Meridiani Planum and Gusev Crater, Mars

Acid-sulfate weathering of basaltic materials is a candidate formation process for the sulfate-rich outcrops and rocks at the MER rover Opportunity and Spirit landing sites. To determine the style of acid-sulfate weathering on Mars, we weathered basaltic materials (olivine-rich glassy basaltic sand and plagioclase feldspar-rich basaltic tephra) in the laboratory under different oxidative, acid-sulfate conditions and characterized the alteration products. We investigated alteration by (1) sulfuric-acid vapor (acid fog), (2) three-step hydrothermal leaching treatment approximating an open system and (3) single-step hydrothermal batch treatment approximating a "closed system." In acid fog experiments, Al, Fe, and Ca sulfates and amorphous silica formed from plagioclase-rich tephra, and Mg and Ca sulfates and amorphous silica formed from the olivine-rich sands. In three-step leaching experiments, only amorphous Si formed from the plagioclase-rich basaltic tephra, and jarosite, Mg and Ca sulfates and amorphous silica formed from olivine-rich basaltic sand. Amorphous silica formed under single-step experiments for both starting materials. Based upon our experiments, jarosite formation in Meridiani outcrop is potential evidence for an open system acid-sulfate weathering regime. Waters rich in sulfuric acid percolated through basaltic sediment, dissolving basaltic phases (e.g., olivine) and forming jarosite, other sulfates, and iron oxides. Aqueous alteration of outcrops and rocks on the West Spur of the Columbia Hills may have occurred when vapors rich in SO2 from volcanic sources reacted with basaltic materials. Soluble ions from the host rock (e.g., olivine) reacted with S to form Ca-, Mg-, and other sulfates along with iron oxides and oxyhydroxides.

Golden, D. C.↗
NASA NTRS1989

Advanced double layer capacitors

There is a need for large amounts of power to be delivered rapidly in a number of airborne and space systems. Conventional, portable power sources, such as batteries, are not suited to delivering high peak power pulses. The charge stored at the electrode-electrolyte double layer is, however, much more assessible on a short time scale. Devices exploiting this concept were fabricated using carbon and metal oxides (Pinnacle Research) as the electrodes and sulfuric acid as the electrolyte. The approach reported, replaces the liquid sulfuric acid electrolyte with a solid ionomer electrolyte. The challenge is to form a solid electrode-solid ionomer electrolyte composite which has a high capacitance per geometric area. The approach to maximize contact between the electrode particles and the ionomer was to impregnate the electrode particles using a liquid ionomer solution and to bond the solvent-free structure to a solid ionomer membrane. Ruthenium dioxide is the electrode material used. Three strategies are being pursued to provide for a high area electrode-ionomer contact: mixing of the RuOx with a small volume of ionomer solution followed by filtration to remove the solvent, and impregnation of the ionomer into an already formed RuOx electrode. RuOx powder and electrodes were examined by non-electrochemical techniques. X-ray diffraction has shown that the material is almost pure RuO2. The electrode structure depends on the processing technique used to introduce the Nafion. Impregnated electrodes have Nafion concentrated near the surface. Electrodes prepared by the evaporation method show large aggregates of crystals surrounded by Nafion.

Sarangapani, S.↗
NASA NTRS1984

The photochemistry of a remote marine stratiform cloud

The coupled gas- and aqueous-phase photochemistry of a stratiform cloud in a remote region of the marine atmosphere is investigated with a time-dependent box model. Both scavenging of ambient acidic aerosols and gases as well as aqueous-phase chemical reactions within droplets are found to be important sources of acidity to cloud water and can lead to pH levels in cloud water in the remote marine atmosphere well below 5.6. The major sources of acidity via aqueous-phase chemical reactions are the generation of sulfuric acid from dissolved SO2 and the generation of formic acid from dissolved formaldehyde. In both cases, aqueous-phase free radicals can play a significant role either directly by oxidizing dissolved SO2 and HCHO or indirectly by producing the aqueous-phase oxidant H2O2. The rate of SO2 conversion to sulfuric acid is sensitive to a variety of parameters including the accommodation or sticking coefficient for SO2, H2O2, HO2, and OH, the liquid water content, and the ambient levels of SO2, HNO3, and other acidic or basic gases. Because high levels of SO2 tend to deplete cloud water of H2O3, the possibility exists that the pH of precipitation in polluted regions will respond nonlinearly to reduced SO2 emissions.

Chameides, W. L.↗
NASA NTRS1982

Ion-induced nucleation in a binary mixture

Recent ion-induced nucleation studies in a binary mixture of H2O and H2SO4 vapors indicate that conventional classical nucleation theories cannot account for the experimentally observed ion-H2O-H2SO4 microcluster spectra. An empirical-analytical, semi-molecular theory of nucleation of a binary mixture of vapors on ions has been developed. This theory includes molecular approach to ion-induced changes in dielectric properties in the immediate neighborhood of an ion core as well as the size dependence of the surface tension of the microcluster. In addition to gaseous sulfuric acid and water molecules, the effect of ion-hydrates and sulfuric acid hydrates has also been considered. This theory is further simplified by using an empirical correction factor for the electrostatic term. This correction factor has been obtained by comparing the simplified model with the molecular dynamics calculations for selected ion hydrate formation. These two theoretical models are then compared with the classical theory for a variety of experimental conditions.

Smith, A. C.↗
NASA NTRS1992

Study and interpretation of the millimeter-wave spectrum of Venus

The effects of the Venus atmospheric constituents on its millimeter wavelength emission are investigated. Specifically, this research describes the methodology and the results of laboratory measurements which are used to calculate the opacity of some of the major absorbers in the Venus atmosphere. The pressure broadened absorption of gaseous SO2/CO2 and gaseous H2SO4/CO2 has been measured at millimeter wavelengths. We have also developed new formalisms for computing the absorptivities of these gases based on our laboratory work. The complex dielectric constant of liquid sulfuric acid has been measured and the expected opacity from the liquid sulfuric acid cloud layer found in the atmosphere of Venus has been evaluated. The partial pressure of gaseous H2SO4 has been measured which results in a more accurate estimate of the dissociation factor of H2SO4. A radiative transfer model has been developed in order to understand how each atmospheric constituent affects the millimeter wave emissions from Venus. Our results from the radiative transfer model are compared with recent observations of the micro-wave and millimeter wave emissions from Venus. Our main conclusion from this work is that gaseous H2SO4 is the most likely cause of the variation in the observed emission from Venus at 112 GHz.

Fahd, Antoine K.↗
NASA NTRS2004

Formation and Stability of Radiation Products in Europa's Icy Shell

Spectra of Europa reveal a surface dominated by water-ice along with hydrated materials and minor amounts of SO2, CO2, and H2O2. Jovian magnetospheric ions (protons, sulfur, and oxygen) and electrons produce significant chemical modifications of the surface on time scales of a few years at micrometer depths. Our laboratory studies examine the formation and stability of radiation products in H2O-rich ices relevant to Europa. Infrared (IR) spectra of ices before and after irradiation reveal the radiation destruction of molecules and the formation of products at 86 - 132 K. In addition, spectra of ices during warming track thermal evolution due to chemical changes and sublimation processes. IR-identified radiation products in 86 - 132 K irradiated H2O + SO2 ices are the bisulfate ion, HSO4(-), sulfate ion, SO4(2-) and the hydronium ion, H3O(+). Warming results in the formation of a residual spectrum similar to liquid sulfuric acid, H2SO4, for H2O:SO2 ratios of 30:1, whereas hydrated sulfuric acid, H2SO4 4 H2O, forms for ratios of 30:1. Radiation products identified for irradiated H2O + H2S ices at 86 K are H2S2 and SO2. When irradiated at 110 and 132 K, ices with H2O:H2S ratios if either 3:1 or 30:1 show the formation of H2SO4 4 H2O on warming to 175 K. We have also examined the radiation stability of H2SO4. Addition of CO2 to H2O + SO2 ices results in the formation of CO3 at 2046 cm (sup -1) (4.89 m). This is the strongest band from a carbon-containing product in the mid-IR spectral region, and it is also seen when either pure CO2 or H2O + CO2 ice is irradiated. Experiments with CH4 added to H2O + SO2 + CO2 ices addressed the question of methane's use as a marker of methanogens in an irradiated ice environment. New results on the near-IR spectrum of pure H2O2 will be included in this presentation. Interpretations of near-IR water bands, with H2O2 present, will be discussed. Irradiations of H2O2 and H2O + H2O2 mixtures, to examine the possibility of O2 and O3 formation, are currently under investigation and new results will be discussed.

Moore, M. H.↗
NASA NTRS1982

Friction and Wear of Iron in Corrosive Media

Friction and wear experiments were conducted with elemental iron exposed to various corrosive media including two acids, base, and a salt. Studies involved various concentrations of nitric and sulfuric acids, sodium hydroxide, and sodium chloride. Load and reciprocating sliding speed were kept constant. With the base NaOH an increase in normality beyond 0.01 N resulted in a decrease in both friction and wear. X-ray photoelectron spectroscopy (XPS) analysis of the surface showed a decreasing concentration of ferric oxide (Fe2O3) on the iron surface with increasing NaOH concentration. With nitric acid (HNO3) friction decreased in solutions to 0.05 N, beyond which no further change in friction was observed. The concentration of Fe2O3 on the surface continued to increase with increasing normality. XPS analysis revealed the presence of sulfates in addition of Fe2O3 on surfaces exposed to sulfuric acid and iron chlorides but no sodium on surfaces exposed to NaCl.

Rengstorff, G. W. P.↗
DOE OSTI2025

Polyethylene Upcycling to Diacids Using Acid-Only Activation

There is a pressing need to develop plastic recycling technologies. Chemical upcycling converts low-value waste plastics into higher-value products. Here, polyethylene (PE) upcycling is accomplished by using acid-only activation of PE (PEAA), thus eliminating costly and toxic organic solvents. Acid mixtures of chlorosulfuric acid (CSA) and sulfuric acid (SA) were used to effectively sulfonate PE, allowing for subsequent facile depolymerization. Molecular deconstruction of sulfonated PE using H 2 O 2 in the presence of an Fe(III) catalyst achieved molar yields of C 2 –C 4 diacids exceeding 40% (based on estimates of acids generated from sulfonates). The sulfonation step using PEAA is hypothesized to follow a shrinking core mechanism (SCM), in which PE particles quickly reach a saturated state in the outer sulfonated layer as CSA diffuses radially inward. This proposed mechanism is supported by the fact that, regardless of the extent of sulfonation, similar molar yields of products and ratios of liberated carbon to sulfur are observed. Modeling and experimentation show that deviations from the SCM occur by lowering the Damköhler number (Da) or increasing CSA solubility in PE. In both cases, CSA diffusion is enhanced, which favors kinetically limited sulfonation.

36 MATERIALS SCIENCE↗
DOE OSTI2024

Lignin content of Populus trichocarpa residues after CELF pretreatment and CBP fermentation

Here we present a dataset of lignin content from a woody energy crop (Populus trichocarpa) residues after a series of co-solvent enhanced lignocellulosic fractionation (CELF) pretreatment and consolidated bioprocessing (CBP) process. The natural poplar variant GW-9947 from the Center for Bioenergy Innovation (CBI) was used. The poplar was knife milled and passed through a 1 mm sieve and CELF pretreatment was performed in a Parr autoclave reactor with 7.5 wt % solids loading, 0.5 wt% H2SO4 as catalyst at 150°C with 5, 15, 25 and 30 minutes, respectively. Tetrahydrofuran was added in a 1:1 mass ratio with water as the pretreatment solvent. The residues from CELF pretreatment were then subjected to CBP using the bacterium C. thermocellum DSM 1313. CBP fermentations were performed at 60 °C in a shaker at 50, 75, and 100 grams/L solids loadings. The Klason lignin was measured using a two-step acid hydrolysis process. In brief, the poplar samples were first hydrolyzed by 72 wt% sulfuric acid at 30 oC for an hour. The hydrolysates were then diluted to 4 wt% sulfuric acid using deionized water and subsequently autoclaved at 121 oC for 1 h. Upon the completion of the two-step hydrolysis, the resulting solution was cooled to room temperature and the precipitate was then filtered through a G8 glass fiber filter through a crucible, dried at oven for overnight, and weighed to get the Klason lignin content. The lignin data provides information about lignin content changes after CELF and C. thermocellum CBP process.

Lignin Populus trichocarpa CELF pretreatment CBP f↗
DOE OSTI2025

Synthesis of highly sulfonated 2,6-diphenyl-p-Phenylene oxide: A highly conductive membrane

Highly sulfonated aromatic polymers are desired for the possible highest performance of polymer electrolytes in fuel cells and electrolyzer applications. Here, we reported the method to prepare highly sulfonated 2,6-diphenyl-p-phenylene oxide (SP3O), a commercially available aromatic polymer, with the highest IEC of 4.42 meq/g. Three sulfonation reagents including chlorosulfonic acid (HSO3Cl), concentrated sulfuric acid (conc. H2SO4), and trimethylsilyl chlorosulfonate (TMSCS) were investigated for single and two-step sulfonation reactions. In addition, DMSO-assisted thermal crosslinking method was applied to prepare crosslinked SP3O membranes to improve their mechanical strength and film-forming ability. Proton exchange membrane from crosslinked SP3O displayed a proton conductivity as high as 250 mS/cm at 95 % RH and 60 °C.

Khomein, Piyachai↗
DOE OSTI2020

Materials Data on Ca3SiCSO24 by Materials Project

Ca3SiO16CO3SO5 crystallizes in the monoclinic P2_1 space group. The structure is one-dimensional and consists of two carbonic acid molecules; two sulfuric acid, monohydrate molecules; and one Ca3SiO16 ribbon oriented in the (0, 1, 0) direction. In the Ca3SiO16 ribbon, there are three inequivalent Ca sites. In the first Ca site, Ca is bonded in a 6-coordinate geometry to six O atoms. There are a spread of Ca–O bond distances ranging from 2.30–2.66 Å. In the second Ca site, Ca is bonded in a 6-coordinate geometry to six O atoms. There are a spread of Ca–O bond distances ranging from 2.31–2.66 Å. In the third Ca site, Ca is bonded in a 6-coordinate geometry to six O atoms. There are a spread of Ca–O bond distances ranging from 2.30–2.67 Å. Si is bonded in a tetrahedral geometry to four O atoms. All Si–O bond lengths are 1.65 Å. There are sixteen inequivalent O sites. In the first O site, O is bonded in a single-bond geometry to one Ca atom. In the second O site, O is bonded in a single-bond geometry to one Ca atom. In the third O site, O is bonded in a single-bond geometry to one Ca atom. In the fourth O site, O is bonded in a bent 120 degrees geometry to two O atoms. There is one shorter (1.29 Å) and one longer (1.30 Å) O–O bond length. In the fifth O site, O is bonded in a bent 120 degrees geometry to two O atoms. There is one shorter (1.29 Å) and one longer (1.30 Å) O–O bond length. In the sixth O site, O is bonded in a distorted tetrahedral geometry to three Ca and one Si atom. In the seventh O site, O is bonded in a bent 120 degrees geometry to two O atoms. There is one shorter (1.29 Å) and one longer (1.30 Å) O–O bond length. In the eighth O site, O is bonded in a 1-coordinate geometry to two Ca and one Si atom. In the ninth O site, O is bonded in a 1-coordinate geometry to two Ca and one Si atom. In the tenth O site, O is bonded in a 1-coordinate geometry to two Ca and one Si atom. In the eleventh O site, O is bonded in a distorted bent 120 degrees geometry to one Ca and one O atom. In the twelfth O site, O is bonded in a distorted bent 120 degrees geometry to one Ca and one O atom. In the thirteenth O site, O is bonded in a distorted bent 120 degrees geometry to one Ca and one O atom. In the fourteenth O site, O is bonded in a bent 120 degrees geometry to one Ca and one O atom. In the fifteenth O site, O is bonded in a bent 120 degrees geometry to one Ca and one O atom. In the sixteenth O site, O is bonded in a bent 120 degrees geometry to one Ca and one O atom.

36 MATERIALS SCIENCE↗
DOE OSTI2025

Sulfate Conversion of Reillex HPQ Anion Exchange Resin for Disposal (Interim Report)

This report describes preliminary data to validate the Savannah River Plutonium Processing Facility’s (SRPPF) flowsheet for conversion of used Reillex HPQ anion exchange resin from the nitrate form to the sulfate form. The nitrate form is an oxidizer and therefore does not meet acceptance criteria for disposal at the Waste Isolation Pilot Plant (WIPP). The purpose of this study is to develop data to support acceptance for this disposition pathway. Due to the challenges characterizing the nitrate concentration on solid resin, the data developed to date are based upon indirect analysis of the ion exchange column effluent by ion chromatography. These challenges are discussed and two methods for quantification of nitrate directly on the resin are recommended for further development: TGA-MS and permanganate digestion followed by IC. The resin used for this work was provided in the chloride form; this is the form in which resin is supplied by the manufacturer. However, it had to be converted to the nitrate form, which is the form that will be used in SRPPF’s ion exchange process, prior to use in the sulfate conversion experiments. The chloride-form resin was characterized. A lab-scale procedure for the conversion of Reillex HPQ resin from the chloride to nitrate form was validated. The nitrate-form resin was assessed for particle size and chloride concentration to ensure it met SRPPF’s facility specifications. The baseline sulfate conversion flowsheet was tested. However, nitrate was still detectable in the effluent after approximately 10 bed volumes of 1 M sodium sulfate had been passed through the resin bed. Additional experiments were performed to assess the effect of increasing the feed volume, reducing the flowrate, the use of 2 M sulfuric acid instead of sodium sulfate, and the use of irradiated resin. The sulfuric acid test was the only one which provided a nondetectable nitrate concentration (<0.002 M) in the effluent. Detectable nitrate in the column effluent suggests that nitrate is still present on the resin itself.

12 MANAGEMENT OF RADIOACTIVE AND NON-RADIOACTIVE W↗
NASA NTRS1973

Intumescent composition, foamed product prepared therewith, and process for making same

An intumescent composition and the foamed product prepared by heating are discussed wherein the composition comprises the reaction product of para-benzoquinone dioxime and a concentrated mineral acid such as sulfuric acid, phosphoric acid, and polyphosphoric acid. The composition is useful as an intumescent agent either by itself or when combined with other materials. A fire-resistant and heat-insulating composition is provided by heating the intumescent composition above its intumescent temperature.

Riccitiello, S. R.↗