- ELECTROREDUCTION OF CHROMIUM (III)-ACETATE COMPLEX TO METALLIC CHROMIUM ON THE COPPER ELECTRODE.
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For commercial purposes chromium is plated mostly from aqueous chromic acid baths. Because of problems including the technical difficulties (i. e. , low current efficiency, high cathode current densities, the relative toxicity of hexavalent chromium), extensive work has been conducted in recent years in order to develop trivalent chromium electrolytes. The purpose of this study is the investigation of the electrodeposition of metallic chromium from chromium (III) acetate. Such a study enables the determination of potentials for which the plating process can occur and, hence, may be useful for further, more detailed investigations.
- Drela,Szynkarczuk,Kubicki
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- Preparation method of acid black 172
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The invention relates to a preparation method of acid black 172. The method comprises the following steps: (1) diazotizing 6-nitro-1-diazo-2-naphthol-4-sulfonic acid by using zinc chloride as a catalyst to obtain a diazo solution; (2) directly adding 2-naphthol into the diazo solution, regulating the pH value with sodium hydroxide, and carrying out coupling to obtain a coupling solution; (3) carrying out chromization on chromic sulfate and acetic acid to obtain a chromizing solution; and (4) adding the chromizing solution into the coupling solution, carrying out complexation, adding salicylic acid to remove chromium to obtain an acid black 172 slurry, and directly carrying out spray drying to obtain the acid black 172 dry powder. The method has the advantages of simple production technique, high production efficiency and fewer side reactions and impurities. The product has the advantages of high quality and no heavy metal chromium, and can be directly subjected to spray drying without salting-out, so the production cost is low.
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Paragraph 0016; 0021; 0025; 0029; 0033
(2016/10/10)
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- AQUEOUS SOLUTIONS OF ORGANIC ACID CHROMIUM(III) SALTS AND PROCESS FOR PREPARATION THEREOF
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An aqueous solution containing an organic acid chromium (III) salt represented by general formula: Crm(Ax)n, wherein A represents a residue left after proton removal from an organic acid; x represents a charge of A; and m and n represent integers satisfying equation 3m+xn=0, is disclosed. The aqueous solution contains the organic acid chromium (III) salt in a concentration of 6% by weight or higher in terms of Crm(Ax)n, has impurity ion concentrations of Na≤30 ppm, Fe≤20 ppm, Cl≤0.001%, SO4≤0.03%, and NO3≤20 ppm per 20 wt% concentration of Crm(Ax)n, and is substantially free from chromium (VI).
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Page/Page column 12
(2009/04/23)
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- Catalyzed process for producing metal carboxylates for use as animal feed supplements
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A catalyzed process is disclosed for producing a polyvalent metal C2 -C3 carboxylate having the formula M(CH3 (CH2)x COO--)y, wherein M is the polyvalent metal cation that is manganese (Mn+2), cobalt (Co+2), or chromium (Cr+3), x is zero or 1 and y is an integer equal to the cationic charge of M. The polyvalent metal C2 -C3 carboxylate is prepared by admixing (i) a dry polyvalent metal compound that is an oxide, hydroxide or carbonate of Mn+2, Co+3 or Cr+3, (ii) an anhydrous C2 -C3 carboxylic acid, and (iii) a catalytic agent at a relative molar ratio of about 1:2-10:0.01-3 in the absence of an added solvent or other diluent to form a reaction mixture. The reaction mixture is heated to complete the reaction, remove the produced water and about 80 percent of the unreacted carboxylic acid. The product in residual carboxylic acid is solidified, ground and the product is recovered. The metal carboxylates can be used as biologically available and economical sources of trace metal ions for supplementation in animal diets.
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- Anhydrous Chromium(III) Carboxylates: Reactions of CrO3 with Carboxylic Acid Anhydrides
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Chromium(VI) oxide reacts with excess of carboxylic acid anhydrides to give pure chromium(III) carboxylates.Their IR and 1H NMR spectra suggest the presence of two different types of carboxylate groups.Magnetic susceptibility and absorption spectra favour an octahedral geometry around Cr. - Keywords: Anhydrous Chromium(III) Carboxylates, Chromium(VI) Oxide, Carboxylic Acid Anhydrides, IR Spectra, Magnetic Moment
- Kapoor, Ramesh,Sharma, Ramneek
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- Method of preparing chromium alkanoates
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Chromic alkanoates, especially the acetate, are prepared by reducing chromic anhydride with an alcohol in the presence of an alkanoic acid, especially acetic acid.
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