Showing papers on "Sodium chlorate published in 1995"

Enantiomorphism in sodium chlorate crystals

Abstract: Creation of enantiomorphous forms in sodium chlorate and enantiomorphous nature of surface micromorphology were studied by optical microscopy. It was shown that when the small number of crystals nucleates spontaneously in unstirred, unseeded solutions then exclusively left- (L) or right-handed (D) crystals can be formed. At the large number of nucleated crystals the probability of the creation of L and D form is nearly the same. L and D crystals can be distinguished by the shape of growth or dissolution centers.

Impurity removal for sodium chlorate

Abstract: Control of sulfate and perchlorate impurity levels is provided in a procedure for manufacturing crystalline sodium chlorate by electrolyzing an aqueous solution of sodium chloride and crystallizing sodium chlorate from the resulting aqueous solution of sodium chlorate and sodium chloride. The mother liquor from the crystallization, or a portion thereof, is treated simultaneously with calcium chloride to remove sulfate ions by precipitating calcium sulfate and with potassium chloride to remove perchlorate ions by precipitating potassium perchlorate.

Quantitative analysis of binary aqueous sodium chlorate and sodium perchlorate solution in the presence of sodium dichromate using Fourier transform infrared spectrometry

Abstract: Infrared spectra of single and mixed aqueous sodium chlorate, sodium perchlorate and sodium dichromate solutions were recorded using Fourier transform infrared spectrometry. With the aid of spectral subtraction and multivariate spectral reconstruction, clear spectra of these salts, in the spectral region 900–1250 cm–1, were obtained. The features of these spectra include maximum absorption bands at 973 cm–1, 1110 cm–1 and 950 cm–1 due to chlorate, perchlorate and dichromate, respectively. In mixed solutions these salts could be detected at concentrations as low as 0.64 g l–1. The linear dynamic range was found to be 0.2–63.8 g l–1, 0–73.47 g l–1 and 0–149 g l–1 for chlorate, perchlorate and dichromate, respectively. The results obtained in the analysis of industrial samples compared well with certified values. Interference effects of different inorganic salts were studied. Sodium salts of bromide, iodate, carbonate, chloride, nitrate, and hydrogencarbonate were found to have no significant interference. Standard deviations of industrial sample determinations were found to be in the range of 2.5–4.10%.

Catalytic and inhibiting effects of lithium peroxide and hydroxide on sodium chlorate decomposition

Abstract: Chemical oxygen generators based on sodium chlorate and lithium perchlorate are used in airplanes, submarines, diving, and mine rescue. Catalytic decomposition of sodium chlorate in the presence of cobalt oxide, lithium peroxide, and lithium hydroxide is studied using thermal gravimetric analysis. Lithium peroxide and hydroxide are both moderately active catalysts for the decomposition of sodium chlorate when used alone, and inhibitors when used with the more active catalyst cobalt oxide.

Process for producing stable chlorine dioxide

Abstract: Chlorine dioxide is prepared by sodium chlorate, sulfuric acid and hydrogen peroxide with proportions 1:1-4:0.3-1.5; dissolve 1 part of sodium chlorate in 1-3 parts of water, drop add into a reaction vessel, the volume ratio of the said three raw materials is 3:4:1, generated chlorine dioxide is absorbed by 5% sodium carbonate. The present method uses alkaline substance to absorb chlorine dioxide, so it is stable and easy to store, it is a highly efficient disinfectant as well as preservative agent.

Chiral Etch Pits on Sodium Chlorate Crystals

Abstract: Microtopography of {100}, {110}, {111}, and {210} surfaces of sodium chlorate crystals etched in various solvents has been studied by optical microscopy. It has been established that etch pits formed on left- and right-handed crystals are chiral, and directions of dissolution steps reveal bond chains of the structure.

Relation between morphology, growth kinetics, and quality of sodium chlorate crystals grown from pure and sodium-dithionate-doped solutions

Abstract: Morphology of as-grown crystals of sodium chlorate obtained from pure solution has been interrelated with growth conditions. Crystals prepared at high cooling rates and supersaturations exhibit pure cubic {100} form. Crystal habit was modified by additional faces of {110} type at decreasing cooling rate and finally a new set of four crystallographically equivalent {111} faces was formed at a very low cooling rate. Surface features of all those types of the faces revealed the layer growth mechanism. Lang topography confirmed the presence of screw dislocations in all sectors under investigation, however, their density and structure is different for low and high cooling rates. Further investigations pointed out that four tetrahedral (111) faces present in the growth form are alternate to those observed in crystals grown from pure solution. X-ray analysis and liquid chromatography analysis of sulphur content confirmed the hypothesis that the impurity was built-in (111) growth sector. Therefore, further analysis of a possible surface site for impurity on these faces was performed and the hypothesis of the stability of these faces is discussed.© (1995) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.

Solubility and Density of Chloric Acid + Sodium Chlorate Solutions

Abstract: Solubilities of sodium chlorate were measured in chloric acid solutions ranging in concentration from 5 to 22 mass % HClO 3 at temperatures of 25, 35, 45, 55, and 65 °C. Densities of saturated solutions were determined by weighing measured volumes of the solutions. Densities of chloric acid solutions and unsaturated chloric acid + sodium chlorate solutions were determined at 25 °C over a range of solution concentrations using a digital density meter. The solubility data and previously reported data from literature sources were correlated with chloric acid concentration and temperature by multilinear regression. All of the data could be represented graphically by a single line by plotting the ratio of sodium chlorate solubility in chloric acid solution to sodium chlorate solubility in water versus mass percent chloric acid. The specific volume of chloric acid at 25 °C is linear with respect to chloric acid concentration. A parameter determined from the slope of this linear plot and the density of crystalline sodium chlorate were used to correlate densities of chloric acid solutions containing sodium chlorate.

Rate of reaction of chlorine dioxide and hydrogen peroxide

Abstract: Because of environmental concerns about molecular chlorine, chlorine dioxide is replacing chlorine in some important industrial applications. This situation has increased the interest in chlorine dioxide and has stimulated research related to its production. One process for manufacturing chlorine dioxide involves reducing sodium chlorate with hydrogen peroxide. In this process, there is a side-reaction in which some chlorine dioxide is consumed by reaction with hydrogen peroxide. Initial rates of this side-reaction were measured in a laboratory batch reactor. The side-reaction rate was compared with the rate that chlorine dioxide is produced under a typical set of industrial conditions: 80 °C, 2 M sulfuric acid, 3.4 M sodium chlorate and 3.2 M sodium sulfate. To make this comparison, an empirical kinetic model of the side-reaction was developed from the experimental data. The reaction approximately follows first-order kinetics for chlorine dioxide and for hydrogen peroxide; the activation energy is 12.4 kcal mol−1. At the cited industrial conditions, the reaction model predicts that chlorine dioxide is consumed by the side-reaction at about 0.8%–1.5% of the rate at which it is produced.

Combustion accelerator for coal

Abstract: The combustion accelerator for promoting full combustion of coal is made of magnesium chloride, potassium nitrate, sodium nitrate, potassium chlorate and sodium chlorate. It is applied by dissolving in water and then mixing with coal. It features that magnesium chloride can loosen coal to prevent coking and other components may be sequentially decomposed at different temp. to raise temp. in stove and thermal efficiency.