Showing papers on "Sodium chlorate published in 1981"

Process for the production of sodium chlorate

Abstract: A process for the production of sodium chlorate comprising electrolyzing an aqueous sodium chloride solution in a diaphragmless sodium chlorate cell, characterized in that an aqueous sodium chloride solution containing, as impurities, calcium, magnesium, barium and the like is contacted with a chelating ion exchange resin to remove the impurities and the resulting saline solution is supplied into a diaphragmless sodium chlorate cell, thereby enabling sodium chlorate to be produced at a stable electrolytic voltage. Further, there is provided a process for the production of sodium chlorate using a combination of a sodium chlorate cell and a cation exchange membrane process type chlorine-alkali cell, characterized in that a weak saline solution taken out of an anode chamber of a cation exchange membrane process type chlorine-alkali cell is supplied with sodium chloride to form an aqueous sodium chloride solution, which is subsequently contacted with a chelating ion exchange resin to remove calcium, magnesium, barium and the like contained as impurities in said solution, and at least part of the resulting purified saline solution is supplied into a sodium chlorate cell, whereby sodium chlorate formed as a by-product in the chlorine-alkali cell can be effectively recovered and the elevation of the electrolytic voltage of the sodium chlorate cell with the lapse of time can be well prevented.

Thermal decomposition of sodium chlorate and chromium(III) oxide mixtures

Abstract: A study of the thermal decomposition of intimate mixtures of sodium chlorate and chromium(III) oxide in different molar ratios was made employing thermogravimetry, differential thermal analysis, chemical analysis, infrared spectroscopy and X-ray diffraction analysis. Sodium chlorate in the presence of chromium(III) oxide starts to decompose around 180°, which is much below the decomposition temperature of pure NaClO3. Each mole of Cr2O3 consumes 8/3 moles of NaClO3, undergoing oxidation to sodium dichromate.

Process for chlorine dioxide production

Abstract: OF THE DISCLOSURE Sodium acid sulphate which is formed as the by-product of a highly efficient process for the production of sub-stantially pure chlorine dioxide by the reduction of sodium chlorate with methanol at high acidity is converted to the more readily handled neutral sodium sulphate while sulphuric acid is recovered by metathesizing the solid sodium acid sulphate recovered from the reaction medium with water.

Manufacture of needlelike goethite

Abstract: PURPOSE:To reduce the particle size and to increase the axial ratio by adding a very small amount of an oxidizing agent to a ferrous salt soln. when alkali is added to the soln. to precipitate and age ferrous hydroxide. CONSTITUTION:Alkali is added to a ferrous salt soln. to precipitate and age ferrous hydroxide at >=11pH, and the ratio of anions to ferrous ions is adjusted to <=1. Potassium chlorate or sodium chlorate is then added to carry out oxidation at <=80 deg.C, thereby manufacturing needlelike goethite. At this time, before precipitating and aging the ferrous hydroxide, an oxidizing agent selected from potassium chlorate, sodium chlorate, potassium nitrate and sodium nitrate is added to the ferrous salt soln. by a very small amount.

Mfg. acicular goethite of small particle size - by adding zinc salt and alkali to ferrous soln., precipitating ferrous hydroxide, adding chlorate and oxidising

Abstract: Mfr. of acicular goethite, comprises adding zinc salt and alkali to aq. ferrous salt soln. to adjust the soln. to above pH 11, pptn. of ferrous hydroxide, adjusting proportion of anion to ferrous ion to below 1, adding sodium chlorate or potassium chlorate, and carrying out oxidn. reaction at below 80 deg.C. The process reduces reaction time and gives acicular goethite having small particle size. In an example, to 1.0L of water there were dissolved 167 g of FeSO4.7H2O and 0.86g of ZnSO4.7H2O, and 168g. of NaOH and water added such that total volume becomes 1.5L. The soln. was allowed to stand for 6h. to form ppte. of ferrous hydroxide. 750mL of supernatant liquid was removed, by which proportion of anion to ferrous ion was adjusted to below 1. Next, to this, there were added 12.3 g of potassium chlorate and 0.37g of sodium silicate soln. and added water such that total vol. becomes 1.5L. The soln. was allowed to react at 50 deg. C for 8 h. The ppte. so produced had the structure of acicular goethite. The magnetic properties of the alloy obtd. by reduction of the acicular goethite (alpha-Fe(O)OH) at 400 deg.C were as follows: Hc:1450 Oe; sigma s:130 emu/g; sigma r/sigma s:0.56. (4oo).