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Showing papers on "Sodium chlorate published in 1997"


Journal ArticleDOI
TL;DR: In this article, the growth and dissolution kinetics of the irradiated and non-irradiated half of a particular crystal were investigated using in situ laser interferometry and X-ray topography.

24 citations


Journal ArticleDOI
TL;DR: In this article, the electrocatalytical activity of the studied cathode materials for the hydrogen evolution reaction (HER) in a chlorate electrolyte was investigated by measuring the overpotential at 250 mA/cm 2 current density (η 250 ).
Abstract: Nanocrystalline Ti-Ru-O alloys of different composition were made by high-energy ballmilling Ti and RUO 2 powders. Upon milling, RUO 2 reacted with Ti to form Ti oxides, Ru-like hexagonal-close-packed (hcp) phase, and a cubic Ti-Ru-(O) alloy. After 40 h of milling, the final- product was primarily a Ti-Ru-O alloy with iron impurities from the steel balls and crucible. A high ball-to-powder weight ratio resulted in higher impurity (iron) content. Most of the iron in the powder did not exist as α-Fe particles but entered into the alloy lattice forming a Ti-Ru-(Fe)-(O) cubic phase. The incorporation of iron did not affect the catalytic performance very much. The electrocatalytical activity of the studied cathode materials for the hydrogen evolution reaction (HER) in a chlorate electrolyte was investigated by measuring the overpotential at 250 mA/cm 2 current density (η 250 ). Good performance was found for Ti/RuO 2 ratios of 2:1 and 3:1. The HER η 250 values for these electrodes were 300 mV lower than that for mild steel cathodes. The electrodes made of the new alloys were very stable in the chlorate electrolyte and had good resistance to poisoning from the solution. The origin of the catalytic activity resulted mainly from ruthenium, and the presence of titanium and oxygen in the alloys was indispensable for the stability of the electrodes.

16 citations


Patent
26 Feb 1997
TL;DR: In this paper, a pre-heated aqueous heat transfer fluid is used to reduce the level of any contamination of the heat-transfer fluid resulting from any wood extractives, any unfixed preservative and/or any particulate matter (i.e. "sludge") that may be present in the fluid.
Abstract: A process for treating wood involving impregnation of the wood with a preservative followed by the heat-fixation of the preservative in the wood using a pre-heated aqueous heat transfer fluid to effect the heat fixation of the preservative. The process particularly relates to steps which are taken to reduce the level of any contamination of the aqueous heat transfer fluid resulting from any wood extractives, any unfixed preservative and/or any particulate matter (i.e. "sludge") that may be present in the fluid. The contamination is preferably reduced by incorporating in the heat transfer fluid an oxidant which will preferentially oxidize any wood extractives resulting from the contact of the treated wood with the fluid without any significant reaction occurring between the oxidant and the preservative. Useful oxidants include inorganic chlorate salts such as sodium chlorate.

9 citations



Patent
08 Jan 1997
TL;DR: Chlorine dioxide is produced by reaction of chlorate ions, usually provided by sodium chlorate, with a persulfate in an aqueous acid reaction medium containing sulfuric acid as discussed by the authors.
Abstract: Chlorine dioxide is produced by reaction of chlorate ions, usually provided by sodium chlorate, with a persulfate in an aqueous acid reaction medium containing sulfuric acid By-product sodium sulfate, sulfuric acid feedstock or mixture may be electrolyzed to form the persulfate for the reaction

6 citations


Patent
09 Oct 1997
TL;DR: In this paper, a fixed-resin bed acid reduction unit (ARU) is used to separate spent acid from chlorine dioxide generators into a de-acidified sodium sulfate component and a purified sulfuric acid component.
Abstract: A process employing a fixed-resin bed Acid Retardation Unit (ARU) to separate spent acid from chlorine dioxide generators into a de-acidified sodium sulfate component and a purified sulfuric acid component. The de-acidified sodium sulfate produced is returned to the chemical recovery cycle of the kraft mill in place of acidic chlorine dioxide generator effluent thereby avoiding the destruction of alkalinity in pulp mill liquors. In addition, sulfuric acid is purified providing an opportunity for reuse in various mill applications, and/or concentrated and recycled to the generator. Alternatively, to avoid high evaporation costs, the purified acid can be used to regenerate a cation-exchange unit (CEU) used in the conversion of sodium chlorate to a sodium chlorate/chloric acid mixture which is fed to the generator in place of sodium chlorate and sulfuric acid. Using this approach, the sulfuric acid requirement of chlorine dioxide generators and, in turn, the amount of acidic generator effluent can be reduced. The process is applicable to both atmospheric and subatmospheric chlorine dioxide generators. In the latter case, the concentration of the purified sulfuric acid from the ARU or any other acid separation system can be increased by using a portion of it to dissolve the sodium sesquisulfate by-product from such generators.

5 citations



Journal ArticleDOI
TL;DR: In this paper, the catalytic activity change of the iron oxide in the presence of barium peroxide and hydroxide is discussed based on the electron configuration change of iron ions.
Abstract: Decomposition of sodium chlorate catalyzed by iron oxide in the presence of barium peroxide and hydroxide is studied by thermogravimetric analysis. Barium peroxide and hydroxide are moderately active catalysts by themselves but are inhibitors when used together with iron oxide. A loading of 1% barium peroxide or hydroxide can significantly reduce the activity of the iron oxide and raise the decomposition temperature of sodium chlorate. The inhibiting effect decreases with increased loading of the barium compounds due to the formation of barium ferrate. The catalytic activity change of the iron oxide in the presence of barium peroxide and hydroxide is discussed based on the electron configuration change of the iron ions.

4 citations



Journal ArticleDOI
TL;DR: In this paper, metastable amorphous or nanocrystalline structures with various degrees of chemical order are studied using X-ray diffraction, scanning Auger microscopy and thermal analyses.
Abstract: Metastable Ti 2 FeRuO x alloys have been produced using three different methods: rapid melt-quenching, vapor phase condensation and high energy ball milling. Depending on the technique used and on the oxygen composition, metastable amorphous or nanocrystalline structures with various degrees of chemical order are produced. The structural properties have been studied using X-ray diffraction, scanning Auger microscopy and thermal analyses. The electrocatalytic properties for the hydrogen evolution reaction in conditions identical to that of the sodium chlorate industry are presented.

2 citations


Patent
28 Apr 1997
TL;DR: In this paper, the authors proposed to prevent an increase of a chlorate concn in a salt water for electrolyzing conveniently and at low cost by subjecting the water to dechlorination to make a replenishing water after decomposing the chlorate by adding hydrochloric acid to a dilute salt water from an electrolytic cell.
Abstract: PROBLEM TO BE SOLVED: To prevent an increase of a chlorate concn in a salt water for electrolyzing conveniently and at low cost by subjecting the water to dechlorination to make a replenishing water after decomposing the chlorate by adding hydrochloric acid to a dilute salt water from an electrolytic cell SOLUTION: The salt being a starting material is dissolved, purified and supplied to the electrolytic cell and electrolyzed by ion-exchange membrane method to obtain chlorine and caustic soda The hydrochloric acid is added to the dilute salt water discharged from this electrolytic cell and containing sodium chlorate so as to obtain 001-03N Then the chlorate is decomposed by retaining the salt water at 70-95 degC for 2-20min After that, the salt water is passed through a dechlorination tower to dechlorinate and used for dissolving the salt being the starting material as the replenishing water In this way, the increase of the chlorate in the salt water for electrolyzing is prevented and a quality deterioration of a caustic soda product is prevented

Journal ArticleDOI
TL;DR: In this article, two-dimensional NQR spectroscopy for correlation of homogeneous and inhomogeneous linewidths has been applied to the 35Cl resonance of sodium chlorate powders of different origin.
Abstract: Abstract Two-dimensional NQR spectroscopy for correlation of homogeneous and inhomogeneous linewidths has been applied to the 35Cl resonance of sodium chlorate powders of different origin. Powder from a ground crystal could be discriminated from technical powder by the ratio of linewidths along the two orthogonal axes in the 2D spectrum. These experiments indicate the applicability of NQR spectroscopy in material science.

Journal ArticleDOI
TL;DR: In this paper, a dual ebulliometric setup was employed to evaluate the vapor pressure−temperature relationship of chloric acid and chloric acids + sodium chlorate mixtures.
Abstract: Chloric acid + sodium chlorate mixtures have been proposed as a substitute for some of the sodium chlorate and sulfuric acid in the generation of chlorine dioxide This paper continues our work on physical property characterization of chloric acid + sodium chlorate solutions A dual ebulliometric setup was employed to evaluate the vapor pressure−temperature relationship of chloric acid and chloric acid + sodium chlorate solutions The natural log of vapor pressures for chloric acid solutions (101−382) mol L-1 over the temperature range (35−79) °C was a linear function of chloric acid concentration and the reciprocal of the temperature Vapor pressures were determined for sodium chlorate + chloric acid solutions for (085−425) mol L-1 sodium chlorate, (073−359) mol L-1 chloric acid, and (35−83) °C All of the data were well correlated by an equation relating the natural log of vapor pressure to sodium chlorate concentration, chloric acid concentration, and the reciprocal of the temperature Some solut