scispace - formally typeset
Search or ask a question
Topic

Sodium dichromate

About: Sodium dichromate is a research topic. Over the lifetime, 421 publications have been published within this topic receiving 6202 citations. The topic is also known as: Disodium salt & sodium bichromate.


Papers
More filters
Patent
17 Oct 2007
TL;DR: In this paper, a method for preparing a dispersing agent includes a step of neutralizing waste generated from a preparation step of nitrotoluenes or oxidizing the waste after neutralization.
Abstract: A method for preparing a dispersing agent is provided to produce a dispersing agent that has excellent dispersion and good stability and reduces phase separation by a consistency increase in a dispersion system. A method for preparing a dispersing agent includes a step of neutralizing waste generated from a preparation step of nitrotoluenes or oxidizing the waste after neutralization. The nitrotoluenes are mononitrotoluenes, dinitrotoluenes, or trinitrotoluenes. The neutralization is performed by using at least one neutralizer selected from the group consisting of sodium hydroxide, calcium hydroxide, potassium hydroxide, and sodium carbonate. The oxidation is performed by using at least one oxidant selected from the group consisting of a Fenton's reagent, hydrogen peroxide, potassium permanganate, potassium dichromate, ozone, sodium dichromate, and potassium persulfate.

1 citations

Patent
19 Oct 2018
TL;DR: In this paper, a production method for high-grade pigment chromium oxide green is described. But the method is not suitable for the production of high-quality products and no pollution is caused; the color of the obtained chromium dioxide green product is more bright, colors close to yellow, close to green, and light color can be achieved.
Abstract: The invention discloses a production method f high-grade pigment chromium oxide green. According to the production method, sodium dichromate, ammonium sulfate (or ammonium carbonate) are taken as rawmaterials; crystallization technology is adopted to produce a ammonium dichromate and sodium sulfate (or sodium carbonate) mixed crystal, a roasting additive is added, high temperature roasting in a rotary kiln is carried out, and at last water washing impurity removing, drying, and crushing are carried out so as to obtain the chromium oxide green product. The beneficial effects are that: the uniformly reacted product is obtained through crystallization process, production and feeding are convenient; the production method is friendly to the environment, and no pollution is caused; the color ofthe obtained chromium oxide green product is more bright, colors close to yellow, close to green, and light color can be achieved, and product standards of Bayer company can be achieved, the productcan be used for replacing inported high-grade pigment chromium oxide green, the market prospect is promising, and the profit value is high.

1 citations

Patent
27 Mar 2014
TL;DR: In this article, a method for producing sodium chromite (NaCrO2), which is characterized by comprising burning a mixture, which is a mixture comprising sodium dichromate (Na2Cr2O7) and a carbon precursor capable of releasing carbon upon being subjected to the thermal decomposition by burning in a vacuum or inert gas atmosphere.
Abstract: The present invention provides a method for producing sodium chromite (NaCrO2) that does not substantially contain hexavalent chromium and has a single phase as observed by X-ray diffraction by an industrially advantageous method using sodium dichromate (Na2Cr2O7). The present invention is a method for producing sodium chromite (NaCrO2), which is characterized by comprising burning a mixture, which is a mixture comprising sodium dichromate (Na2Cr2O7) and a carbon precursor capable of releasing carbon upon being subjected to the thermal decomposition by burning in a vacuum or inert gas atmosphere, in a vacuum or inert gas atmosphere. In the method, the temperature for the burning is preferably 700 to 1200˚C.

1 citations

Patent
28 Jul 1964
TL;DR: In this paper, a chromium trioxide (chromic acid) is added to a bath containing per litre 100 g. CrO3 and 6 g. H2SiF6 in a lead vessel as anode containing a 1 cm. diameter steel rod as cathode and electrolysis is effected at 80 DEG C. with a cathode current density of 100 amps/dm2 at 4 volts and chromic oxide being continuously added.
Abstract: Pure chromium is continuously cathodically electrodeposited from an aqueous solution of chromium trioxide (chromic acid) in the presence of fluosilicic or hydrofluoric acid to which is added at a rate corresponding to that of chromium deposition a solid pure hydrated chromic oxide obtained by reducing a solution of sulphate-free alkali chromate or dichromate with an organic reducing agent at an elevated temperature in an autoclave and filtering off the resulting chromic oxide. As described pure hydrated chromic oxide so produced is added to a bath containing per litre 100 g. CrO3 and 6 g. H2SiF6 in a lead vessel as anode containing a 1 cm. diameter steel rod as cathode and electrolysis is effected at 80 DEG C. with a current of 20 amps. at 4 volts to oxidize the chromic oxide to give a bath having hexavalent Cr content of 156 g/1. Part of this bath is used in the production of the chromic oxide to remove its alkali content and to the remainder is added a further 6 g/1 of H2SiF6 to form the initial chromium electrodeposition bath, electrodeposition of chromium then being effected at 95 DEG C. with a cathode current density of 100 amps/dm2 at 4 volts and chromic oxide being continuously added.ALSO:Pure hydrated chromic oxide consisting of .71 to 75%.Cr2O3 .0.05%.Na2O .\sT0.005%.Fe2O3 .\sT0.002%.S .remainder.water is prepared by (i) dissolving commercial sodium dichromate containing 0.3% S in water and bringing pH to 2 with HCl, (ii) precipitating sulphate cone with BaCl2 removing 99% of the sulphur, (iii) heating the filtrate with wood meal in a sealed autoclave at 250 DEG C. with stirring to yield a granular hydrated brilliant green oxide, (iv) washing until alkalinity is no longer detectable, and (v) removing alkali metal content by treatment with sulphate-free chromic acid solution. The chromic acid solution may be obtained by electrolytic oxidation of pure hydrated chromic oxide in a chromic acid-fluosilicic acid bath.

1 citations

Journal ArticleDOI
TL;DR: In this paper, the influence exerted by the conditions of synthesis of residual graphite hydrosulfate in a system constituted by concentrated sulfuric acid and saturated aqueous solution of sodium dichromate on the properties of the final product was studied in a wide range of reagent consumptions.
Abstract: The influence exerted by the conditions of synthesis of residual graphite hydrosulfate in a system constituted by concentrated sulfuric acid and saturated aqueous solution of sodium dichromate on the properties of the final product was studied in a wide range of reagent consumptions. The swelling coefficient and the loss of the product were analyzed as functions of the intercalate content in the product.

1 citations


Network Information
Related Topics (5)
Aqueous solution
189.5K papers, 3.4M citations
68% related
Cobalt
69.8K papers, 1.2M citations
68% related
Copper
122.3K papers, 1.8M citations
67% related
DNA damage
47K papers, 2.4M citations
65% related
Environmental exposure
37.4K papers, 1.8M citations
65% related
Performance
Metrics
No. of papers in the topic in previous years
YearPapers
20211
20201
201916
201817
20178
201617