Showing papers on "Sodium chlorate published in 2000"
128 citations
TL;DR: The generation of secondary crystals of sodium chlorate when a saturated solution of Sodium chlorate is simply made to flow over a sodium bromate crystal is reported, which clearly shows that fluid flows alone can generate and disperse secondary nuclei.
Abstract: Chiral symmetry breaking in stirred crystallization of sodium chlorate ( ${\mathrm{NaClO}}_{3}$) occurs via the production of secondary crystals from a single ``mother crystal.'' Martin, Tharrington, and Wu [Phys. Rev. Lett. 77, 2826 (1996)] investigated this phenomenon and concluded that it was mechanical crushing of a crystal by the stir bar, not convection, that produces secondary crystals from a single crystal. Here we report the generation of secondary crystals of sodium chlorate when a saturated solution of sodium chlorate is simply made to flow over a sodium bromate ( ${\mathrm{NaBrO}}_{3}$) crystal. This clearly shows that fluid flows alone can generate and disperse secondary nuclei.
62 citations
TL;DR: Results indicate that preharvest desiccant applications should not be made prior to G. max maturity (R7), and glyphosate + sodium chlorate applied at R7 reduced germination of the glyphosate-tolerant cultivar and increased the number of abnormal seedlings produced in the conventional cultivar.
Abstract: The effect of two commonly used desiccant tank mixtures on Glycine max seed production and viability when applied at G. max growth stages R5 to R8 (R5 = beginning pod fill, R6 = full green pod, R7 = beginning maturity, R8 = full maturity) was evaluated. Two mid-Group IV G. max cultivars, one conventional (‘Northrup King 4260’) and one glyphosate-tolerant (‘Asgrow 4701RR’), were evaluated. Tank mixtures containing either glyphosate + sodium chlorate or paraquat + sodium chlorate + surfactant reduced yield, seed weight, and subsequent germination, emergence, and seedling growth when applied at R5 or R6 to either G. max cultivar. Glyphosate + sodium chlorate applied at R7 reduced germination of the glyphosate-tolerant cultivar. When applied at R6 or R7, glyphosate + sodium chlorate reduced the next generation's seedling length compared to paraquat + sodium chlorate. Glyphosate + sodium chlorate increased the number of abnormal seedlings produced in the conventional cultivar compared to paraquat + so...
43 citations
TL;DR: In this paper, an electrothermal vaporization-inductively coupled plasma mass spectrometric (ETV-ICP-MS) method based on the suppression of ruthenium by using nitric acid and sodium chlorate as modifiers has been developed for determination of 99 Tc.
23 citations
04 Dec 2000
TL;DR: Chlorine dioxide has been shown to be an effective biocide as well as an effective oxidizer for the control of total trihalomethanes, in drinking water treatment to meet USEPA drinking water regulations.
Abstract: Chlorine dioxide is finding increasing use as an oxidizing bleaching agent in the pulp and paper industry, replacing chlorine gas and aqueous sodium hypochlorite. Chlorine dioxide significantly reduces the quantity of adsorbable organically bound halide (AOX) effluents produced in the paper pulp bleaching process while producing high brightness paper with excellent mechanical strength. Increasing chlorine dioxide bleaching substitution levels in the pulp mills as well as the need for a chlorine-free gas for bleaching are the driving forces for design/process changes in the commercial chlorine dioxide generators that use sodium chlorate.
Chlorine dioxide is also increasing in usage as a disinfectant or biocide in municipal and industrial water treatment as well as an oxidizer in oil field and pollution abatement processes. Sodium chlorite is the choice precursor chemical for generating chlorine dioxide gas in quantities of less than about 2000 kg/d. Chlorine dioxide has been shown to be an effective biocide as well as an effective oxidizer for the control of total trihalomethanes, in drinking water treatment to meet USEPA drinking water regulations. Methods for the removal of the disinfection by-products produced from chlorine dioxide treatment, such as chlorite and chlorate, are being developed to alleviate toxicological concerns about their presence in drinking water.
Keywords:
Chlorine dioxide;
Reductants;
Pulp bleaching;
Biocide;
Sulfur dioxide;
Sodium chlorite;
Disinfection;
Water treatment
19 citations
TL;DR: Macroporous S/DVB copolymer containing N, N -dichlorosulfonamide groups was used for removal of thiocyanate ions from aqueous solutions as mentioned in this paper.
14 citations
Patent•
13 Jan 2000
TL;DR: In this article, a novel method is described whereby chlorine dioxide is produced through the chemical reduction of ammonium chlorate in an aqueous acidic solution, and the reduction reaction takes place at elevated temperatures with or without a catalyst.
Abstract: A novel method is described whereby chlorine dioxide is produced through the chemical reduction of ammonium chlorate in an aqueous acidic solution. The reduction reaction takes place at elevated temperatures with or without a catalyst. The reducing agent of this reaction is preferably hydrogen peroxide, glycerol, or sucrose. Chlorine dioxide may be produced in accordance with this invention at a substantially higher rate and in higher yield than with conventional methods using sodium chlorate. Further, the chlorine dioxide produced is substantially chloride-free. The ammonium sulfate by-product of this method has direct use as a fertilizer.
10 citations
TL;DR: In this paper, the optimum concentration of sodium formate was found to be 18 g/dm 3 at a temperature of approximately 100°C where the process time was 5 hours.
4 citations
Patent•
26 Jul 2000
TL;DR: In this paper, a process based on hydrochloric acid for preparing stable ClO2 solution includes such steps as reaction of sodium chlorate as oxidant on HCL as reducer to generate the mixed gas of ClO 2gas and Cl2 gas, purifying with solution of sodium chloride to generate pure ClO dioxide gas, and stabilizing and adsorption with sodium hydroxide or sodium carbonate and H2O2.
Abstract: A process based on hydrochloric acid for preparing stable ClO2 solution includes such steps as reaction of sodium chlorate as oxidant on hydrochloric acid as reducer to generate the mixed gas of ClO2gas and Cl2 gas, purifying with solution of sodium chlorite to generate pure ClO2 gas, and stabilizing and adsorption with sodium hydroxide or sodium carbonate and H2O2. The process takes place in negative pressure generated by hydraulic sprayer. Its advantages are simple operation, less investment in equipment and high purity of ClO2.
4 citations
Patent•
26 Jul 2000
TL;DR: In this article, a process for preparing stable ClO2 solution based on methanol includes the steps of reaction in sulfuric medium to generate ClO 2 gas using sodium chlorate as oxidant and methanolate as reducer, stabilizing and adsorption with sodium hydroxide or sodium carbonate and H2O2.
Abstract: A process for preparing stable ClO2 solution based on methanol includes the steps of reaction in sulfuric medium to generate ClO2 gas using sodium chlorate as oxidant and methanol as reducer, stabilizing and adsorption with sodium hydroxide or sodium carbonate and H2O2. Said reaction takes place in condition of negative pressure generated by hydraulic water sprayer and the methanol is continuallyfeeded. Its advantages are simple operation, low production cost, high utilization rate of raw materials and high purity of ClO2.
3 citations
Patent•
17 Oct 2000
TL;DR: In this article, the surface of metallic sliding parts is brought into contact with a surface treating soln, forming an amorphous chemical film excellent in initial conformability, wear resistance, seizuring resistance, lubricity and adhesion on the sliding parts of metallic alloy steel.
Abstract: PROBLEM TO BE SOLVED: To provide a surface treating soln. forming an amorphous chemical film excellent in initial conformability, wear resistance, seizuring resistance, lubricity and adhesion on the sliding parts of metallic alloy steel and to provide a surface treating method. SOLUTION: The surface of metallic sliding parts is brought into contact with a surface treating soln. using, as the main base material, tungsten primary phosphate, using sodium chlorate, sodium hypochloride and sodium perchloride as the main oxidizers, contg. sodium nitrate, nickel nitrate, sodium nitrite and sodium bromate and moreover contg., at need, molybdic ions, fluoride ions and copper ions, to form an amorphous chemical film.
04 Dec 2000
TL;DR: Chloric acid technologies have been developed which allow the generation of chlorine dioxide directly from the acid, without the formation of sodium salts in the generator as mentioned in this paper, which minimizes sodium chloride and sodium dichromate impurities.
Abstract: Sodium chlorate is the primary raw material for the manufacture of chlorine dioxide, a bleaching agent in the pulp and paper industry. Increases in the chlorine dioxide substitution for chlorine in pulp bleaching have resulted in an average growth of 12%/y in production. Sodium chlorate is prepared electrolytically. The modern technology described minimizes sodium chloride and sodium dichromate impurities. Chlorates are powerful oxidizers, and they are also used in perchloric salt and uranium production.
Chloric acid technologies have been developed which allow the generation of chlorine dioxide directly from the acid, without the formation of sodium salts in the generator.
Patent•
20 Jun 2000
TL;DR: In this article, an anhydrous solution of sodium perchlorate, from one electrolysis or a sequence of electrolysis stages of sodium chlorate, is submitted to an evaporation under vacuum at 52-75 deg C and at an absolute pressure of 1500-7000 Pa.
Abstract: Preparation of anhydrous sodium perchlorate crystals in which an aqueous solution of sodium perchlorate, from one electrolysis or a sequence of electrolysis stages of sodium chlorate, is submitted to an evaporation under vacuum at 52-75 (preferably 60-70) deg C and at an absolute pressure of 1500-7000 Pa. An Independent claim is included for the sodium perchlorate crystals obtained.