Showing papers on "Sodium dichromate published in 2012"
06 May 2012
TL;DR: A method for estimating ethanol in alcoholic-drinks by direct reaction is presented and the absorbance maxima for the ethanol was found to be 578 nm.
Abstract: A method for estimating ethanol in alcoholic-drinks by direct reaction is presented. The method consist of color reaction of ethanol with sodium dichromate. The colorimetric quantification was based on the formation of green colored chromate ions resulting from treatment of ethanol and sodium dichromate as limiting reactant in presence of sulfuric acid and acetate buffer pH 4.3. The absorbance maxima for the ethanol was found to be 578 nm. The influence of acetate buffer pH, reaction time, and Beer’law on color development and sensitivity were investigated and optimal assay conditions established. The limits of detection and quantification for ethanol were determined to be 0.6 mg/mL and 1.9 mg/mL.
52 citations
TL;DR: Data suggest that Cr(VI)-induced carcinogenesis in the rodent alimentary canal involves oxidative stress; however, differences in histopathology, cytokines, and iron status suggest potential contributions from other factors as well.
50 citations
15 citations
Patent•
01 Aug 2012
TL;DR: In this article, the utility model relates to a high-efficiency iron rust conversion agent, and belongs to the field of antirust paint, where the conversion agent comprises the following raw materials by weight: 1-10% of zinc oxide, 20-40% of phosphoric acid, 5-15% of dichromate, 0.5% of metal oxides, 5% of phosphate, 1% of corrosion inhibitor and 50-70% of solvent.
Abstract: The utility model relates to a high-efficiency iron rust conversion agent, and belongs to the field of an antirust paint The iron rust conversion agent comprises the following raw materials by weight: 01-10% of zinc oxide, 20-40% of phosphoric acid, 05-15% of dichromate, 05-10% of phosphate, 01-10% of corrosion inhibitor, and 50-70% of solvent, wherein the dichromate is potassium dichromate or sodium dichromate; the phosphate is sodium phosphate or potassium phosphate; the corrosion inhibitor is urotropine or urea; and the solvent is water or ethanol The preparation method comprises the steps as follows: sequentially adding the solvent, the phosphoric acid, the dichromate, the phosphate, the corrosion inhibitor and the zinc oxide to a glass cup under persistently stirring according to the mass ratio, and dissolving for 10-20 min The production method bases on the dissolving of the solid reactants in the phosphoric acid solution The phosphorized film formed by iron rust conversion has the effects of preventing rust and fixing remnant rust, and the formed phosphorized layer protective film is long-acting, and stable in atmospheric environment, lubricating oil and organic solvent, has high adhesion, can be used as a primer, has dielectric properties, and can prevent electro-chemical corrosion on the metal surface
11 citations
Patent•
26 Sep 2012
TL;DR: In this paper, a method for producing sodium fluosilicate by utilizing waste water containing sodium sulfate is presented, where the dilute sulphuric acid as a side product is used for a production line of sodium dichromate.
Abstract: The invention discloses a method for producing sodium fluosilicate by utilizing waste water containing sodium sulfate. The method is as follows: generating the sodium fluosilicate by adopting the waste water containing sodium sulfate and fluosilicic acid as a side product for producing hydrofluoric acid as a raw material; and obtaining a sodium fluosilicate product by curing, filtering, cleaning and pneumatic drying. The dilute sulphuric acid as a side product is used for a production line of sodium dichromate. The method provided by the invention has the advantages that the industrial sodiumsulfate waste water is utilized to produce the sodium fluosilicate, and the materials are all industrial waste water. The industrial waste water of the sodium sulfate is from waste water obtained by washing chromium sesquioxide produced by sodium dichromate or waste water generated for producing chromium salt, the fluosilicic acid is from waste water in the process for producing the hydrofluoric acid, the produced sodium fluosilicate is used as a commodity for sales, the dilute sulphuric acid as a side product is used for the production line of the sodium dichromate. By utilizing the method, the cost for treating the waste water treatment of the industrial sodium sulfate in the chromium salt industry is reduced, and the reutilization of water resources is realized.
10 citations
TL;DR: Evaluating the genotoxicity of Supermint herbal medicine in DNA breakage of rat hepatocytes in comparison with sodium dichromate by single cell gel electrophoresis technique or comet assay convinced that the crude extract of Super Mint in vitro did not have mutagenic effect.
Abstract: Purpose: The increasing use of herbal drugs and their easy availability have necessitated the use of mutagenicity test to analyze their toxicity and safety. The aim of this study was to evaluate the genotoxicity of Supermint herbal medicine in DNA breakage of rat hepatocytes in comparison with sodium dichromate by single cell gel electrophoresis technique or comet assay. Methods: Hepatocytes were prepared from male wistar rats and were counted and kept in a bioreactor for 30 minutes. Then cells were exposed to the Supermint herbal medicine at doses of 125, 250 and 500 µl/ml. Buffer 4 (incubation buffer) and sodium dichromate were used as negative and positive control for one hour respectively. Then cell suspension with low melting point agarose were put on precoated slides and covered with agarose gel. Then lysing, electrophoresis, neutralization and staining were carried out. Finally the slides were analyzed with fluorescence microscope. The parameter under this analysis was the type of migration which was determined according to Kobayashi pattern. Results: With increased dose of Supermint herbal medicine the DNA damage was slightly increased (Pl0001). Conlusion: In overall compared to the positive control significant differences is observed which convinced that the crude extract of Supermint in vitro did not have mutagenic effect.
7 citations
Patent•
29 Aug 2012
TL;DR: In this paper, a preparation method of sodium bichromate is proposed, which consists of: (1) adding 700-1,350 g.L sodium chromate neutral solution of a chromium compound in terms of Na2Cr2O7.2H2O into a carbonization reactor; (2) continuously supplying carbon dioxide into the carbonisation reactor, and controlling partial pressure of carbon dioxide to be 0.01-1.5 MPa, reaction temperature to be 15-105 DEG C and reaction time to be0.5-8.
Abstract: The invention provides a preparation method of sodium bichromate. The preparation method comprises the following steps of: (1) adding 700-1,350 g.L sodium chromate neutral solution of a chromium compound in terms of Na2Cr2O7.2H2O into a carbonization reactor; (2) continuously supplying carbon dioxide into the carbonization reactor, and controlling partial pressure of carbon dioxide to be 0.01-1.5 MPa, reaction temperature to be 15-105 DEG C and reaction time to be 0.5-8.0 h; (3) separating carbonized feed liquid obtained by the step (2) to obtain carbonized liquid and sodium bicarbonate crystals, wherein the concentration of the chromium compound in the carbonized liquid is 700-1,350 g.L in terms of Na2Cr2O7.2H2O; and (4) crystallizing and dehydrating the carbonized liquid to obtain the sodium bichromate. By preparing the sodium bichromate through the preparation method, the conversation rate from the sodium chromate to the sodium dichromate can reach 95-100 percent, the quality of the sodium bichromate is high, and the sulfate content is less than 0.1 percent by weight.
6 citations
Patent•
08 Aug 2012
TL;DR: In this paper, a method for producing hydrated chromium oxide green is described. But the method is not suitable for the production of green seriflux, and it requires high recovery rate, no environmental pollution and operational simplicity.
Abstract: The invention discloses a method for producing hydrated chromium oxide green. The mehtod with has high recovery rate, no environmental pollution and operational simplicity aims to solving the problems of poor performance, weak covering ability, low oil absorption capacity, low pigment brightness, high concentration of hydrotrope, containment of trace hexavalent chromium, low vanadium removal performance and the like of pigments prepared by traditional methods . The method provided in the invention includes the following steps that: with sodium dichromate or chromic anhydride being used as a raw material, and sucrose or starch being used as a reducing agent, the raw material and the reducing agent are mixed with water; the mixture is placed in a thermal pressure reactor for a thermal pressure reaction for 0.5 to 1 hour at a temperature of 200 DEG C to 280 DEG C under a pressure of 4 MP to 8 MP to obtain a hydrated chromium oxide green seriflux; filtering and washing are applied on the obtained seriflux; and the obtained substance is dried at the temperature from 70 DEG C to 80 DEG C for 2 to 3 hours to obtain a hydrated chromium oxide green product. In the process of vanadium removal in calcium-free roasting of sodium dichromate, the hydrated chromium oxide green produced by the method provided in the invention is used as a neutral liquid vanadium removal agent to substitute lime for vanadium removal, characterized by highly efficient vanadium removal, capability of recycling and zero emission of waste residue.
5 citations
Patent•
28 Nov 2012
TL;DR: In this paper, a ternary composite chain scission solution was proposed to improve the chain scissoring and unblocking effects, maintain a long unblocked time, and enhance crude oil recovery.
Abstract: Belonging to fine chemical solutions, the invention relates to a ternary composite chain scission solution used for ternary composite flooding chain scission and unblocking as well as enhancement of crude oil recovery. According to a formula, the chain scission solution comprises by weight: 8%-10% of sodium lauryl sulfate, 3.5%-4% of potassium persulfate, 7%-8% of sodium dichromate, 9%-10% of an imidazoline inhibitor, 10%-12% of sodium hydroxide, 8%-10% of a ferric ion stabilizer, and the balance water. Compared with current common acidification, surfactants and other chemical blockage removal technologies, the chain scission solution not only can effectively improve the chain scission and unblocking effects, maintain a long unblocked time, enhance crude oil recovery, but also is a novel environment-friendly product with a pH value of 8 and without irritating smell and corrosion.
5 citations
TL;DR: The statistical analysis of the obtained results showed that with an increase in the dosage of A. draconculus, DNA damage also increased significantly (P < 0.05), which will be helpful in ensuring rational use of this drug.
Abstract: Background: The increasing use of herbal drugs and their easy availability have necessitated the use of mutagenicity tests to analyze their toxicity and safety. Objectives: The aim of this study was to determine the in vitro mutagenicity of Artemisia draconculus L., a herbal drug, by performing single cell gel electrophoresis (SCGE). Material and Methods: In this study, we obtained a herbal drug with A. draconculus at a density of 0.94; doses of 100 μl, 200 μl, 400 μl, and 800 μl equivalent to 94 mg, 188 mg, 376 mg, and 752 mg of A. draconculus, respectively, were used. Sodium dichromate at a dose of 262 mg was considered to be the positive control, and blood was considered to be the negative control. Blood samples were centrifuged at 3500 rpm for 5 min, and the lower portion of the residue was isolated and mixed with low melting point agarose. Results: A cell suspension was prepared and applied on pre-coated agarose gel slides. Lysis, electrophoresis under alkaline conditions, staining of DNA, comet visualization, and comet scoring were carried out. The statistical analysis of the obtained results showed that with an increase in the dosage of A. draconculus, DNA damage also increased signifi cantly (P < 0.05). Conclusions: These findings provide valuable information regarding the safety and tox icity of this herbal drug, and this information will be helpful in ensuring rational use of this drug.
2 citations
Patent•
01 Aug 2012
TL;DR: An oxidant for dyeing of a sulfide dye comprises components of sodium chlorate, sodium vanadate or ammonium vanadates, sodium chloride and water for adjusting concentration as discussed by the authors.
Abstract: An oxidant for dyeing of a sulfide dye comprises components of sodium chlorate, sodium vanadate or ammonium vanadate, sodium chloride and water for adjusting concentration. The part of weight of each component is that sodium chlorate 10-80 parts, sodium vanadate or ammonium vanadate 0.5-10 parts, sodium chloride 1-60 parts, the remaining part is water, wherein the use environment of the oxidant is that a dye vat of a jig dyeing machine contains 0.5-4% (o.w.f) of oxidant, 98% of acetic acid or 30% of sulfuric acid 1-6% (o.w.f) and four to six paths (note: the distance of one path is from one end of a roll of dye cloth to the other end of the roll of dye cloth in the dye vat), and temperature is 60-65DEG C. The oxidant for dyeing of the sulfide dye selects chlorate with low price to serve as an oxidation treatment agent, solves the problem of serious environment pollution caused by traditional sodium dichromate oxidation treatment, color fastness and hydrophilism are good, convenient conditions are provided for treatment after dyeing, repeated water washing and multiple soaping and color toning are not needed after oxidation treatment, and the problems of cloth surface sour, rough touch and dark color and light are solved.
Patent•
22 Aug 2012
TL;DR: In this paper, the authors proposed a method for continuously neutralizing and decontaminating a sodium chromate alkali solution, which comprises the following step of adding a neutral aqueous solution containing sodium chromates and an optional crystal seed which are used as bottom materials in a neutralization reactor for realizing neutralization and decentamination based on carbon dioxide as a neutralizing agent or chromium-containing acidic wastewater.
Abstract: The invention relates to a method for continuously neutralizing and decontaminating a sodium chromate alkali solution. The method comprises the following step of: adding a neutral aqueous solution containing sodium chromate and an optional crystal seed which are used as bottom materials in a neutralization reactor for realizing neutralization and decontamination based on carbon dioxide as a neutralizing agent or chromium-containing acidic wastewater which is produced in the process of producing sodium bichromate from sodium chromate, a pre-acidification solution, an acidification solution, a sodium bichromate mother liquid, a sodium dichromate aqueous solution and inorganic acid, or any mixture of the former neutralizing agents. Through the control over the concentration, temperature, pH value and stirring speed of a reaction liquid, precipitate obtained by the method is large in particle and rapid in sedimentation speed; aluminum mud is good in filtering property and is easy to wash; and the content of hexavalent chromium in the aluminum mud in greatly reduced, thereby reducing the discharge amount of the aluminum mud. In addition, the neutralization reactor the upper part of which is provided with an overflowing port is adopted for neutralization reaction, so that the automation and continuty of the neutralization and decontamination process of the sodium chromate alkali solution are realized.
Patent•
25 Jul 2012
TL;DR: In this article, a clean method for preparing high loose density chromic oxide was proposed, which consisted of the following steps: causing chromic salts which are used as raw materials to react with reducing gas which is used as a reducing agent at 300-800 DEG C for 0.5-5 hours, cooling, washing the reaction mixture with water, filtering and drying, thus obtaining an intermediate product; carrying out after heat preservation on the intermediate at 350-550 DEGC for 0-5hours; and calcining the product after heat-preserving at 850-
Abstract: The invention discloses a clean method for preparing high loose density chromic oxide. The method comprises the following steps: causing chromic salts which is used as raw materials to react with reducing gas which is used as a reducing agent at 300-800 DEG C for 0.5-5 hours, cooling, washing the reaction mixture with water, filtering and drying, thus obtaining an intermediate product; carrying out after heat preservation on the intermediate at 350-550 DEG C for 0-5 hours; and calcining the product after heat preservation at 850-1150 DEG C for 0-6 hours, washing and drying, thus obtaining thehigh loose density chromic oxide. The chromic salts are potassium chromate and sodium chromate or potassium dichromate and sodium dichromate; and the reducing gas is one or a mixture of hydrogen gas,natural gas, ammonia gas and coal gas.
Patent•
21 Mar 2012
TL;DR: In this paper, a method for controlling the performance stability of a lithium chloride dehumidizer was proposed, in which a lithium hydroxide solution is added into a LiCl solution in separate times with equal quantity so that the ph value of the LiCl mixture approaches to 7 and the acidity and corrosivity of LiCl is reduced.
Abstract: The invention discloses a method for controlling the performance stability of a lithium chloride dehumidizer In the invention, a lithium hydroxide solution is added into a lithium chloride solution in separate times with equal quantity so that the ph value of the lithium hydroxide solution approaches to 7 and the acidity and corrosivity of the lithium hydroxide solution are reduced; furthermore, a sodium dichromate solution is also added in separate times with equal quantity; the sodium dichromate has strong oxidability; and after being mixed with the lithium chloride solution, the corrosivity of the sodium dichromate is reduced By adopting the method disclosed by the invention, corrosion on the machinery equipment can be reduced, and the cost is saved for the enterprises
Patent•
02 May 2012
TL;DR: In this paper, a method for treating fly ash of a chromic salt rotary kiln was proposed, which comprises the steps of subjecting fly ash to slurrying, filtering and washing so as to obtain soda ash and a sodium chromate solution.
Abstract: The invention relates to a method for treating fly ash of a chromic salt rotary kiln. The method comprises the steps of: 1) subjecting fly ash to slurrying, filtering and washing so as to obtain soda ash and a sodium chromate solution; 2) conducting pressurized carbonization to the soda ash and the sodium chromate solution, then carrying out filtering so as to obtain a sodium bicarbonate sedimentand a sodium chromate filtering solution; 3) filtering the obtained sodium bicarbonate sediment and drying it, then returning the sediment to the chromic salt rotary kiln for batching, and leaving the obtained sodium chromate filtering solution to flow into a sodium dichromate production line. The method of the invention can fully recover useful components (soda ash, chromite and sodium chromate)in the fly ash of a chromic salt rotary kiln, and realize comprehensive utilization of fly ash.
Patent•
11 Apr 2012
TL;DR: In this paper, a method for improving industrial sodium dichromate finished product content was proposed, which comprises the steps of: controlling the acidification rate of a sodium chromate neutral solution of 260g/L-320g/l at 106%-108, conducting evaporation, filtering and mirabilite removing, then adding a sodium-chromate neutral liquid of certain proportion into the obtained sodium dichrome filtrate of 1150g /L-1250g/
Abstract: The invention discloses a method for improving industrial sodium dichromate finished product content. The method comprises the steps of: controlling the acidification rate of a sodium chromate neutral solution of 260g/L-320g/L at 106%-108%, conducting evaporation, filtering and mirabilite removing, then adding a sodium chromate neutral liquid of certain proportion into the obtained sodium dichromate filtrate of 1150g/L-1250g/L so as to make the acidification rate at 102%-104%, continuing evaporation till sodium dichromate content of 1600g/L-1800g/L, carrying out insulation and sedimentation for 6-8h, extracting the clear liquid of an upper layer, and leaving it to forced cooling for crystallization, performing centrifugal separation so as to obtain an industrial sodium dichromate finishedproduct. Thus, the content of existing non-calcium roasted industrial sodium dichromate finished products can be improved from 98%-98.3% to 98.5%-99.5%, thus reaching the purpose of enhancing the quality of industrial sodium dichromate finished products.
09 Aug 2012
TL;DR: In this paper, the inroduction of olefinic double bond at AB-ring juncture influences the cleavage of γ-lactone ring to the diol in contrast to the parent odollactone that gives the carboxylic acid.
Abstract: Oxidative rearrangement of odollactone has been carried out with hydrogen peroxide containing p-toluene sulphonic acid in dichloromethane. The products obtained were characterised by chemical transformation using selenium dioxide in acetic acid, sodium dichromate in acetic acid and Li in ethylenediamine followed by spectral analysis. The in- troduction of olefinic double bond at AB-ring juncture influences the cleavage of γ-lactone ring to the diol in contrast to the parent odollactone that gives the carboxylic acid.