RU2154029C2 - Method of preparing cobalt carbonate from chloride solution - Google Patents

Abstract

FIELD: chemical industry, particularly, preparation of salts, more specifically preparation of cobalt carbonate. SUBSTANCE: cobalt chloride solution is poured into precipitator solution, e.g. alkali metal or ammonium hydrocarbonate. Reaction is carried out in excessive amount of precipitant, and its concentration is further reduced till completion of reaction. Precipitate is filtered, washed with water to remove chlorine ion and dried. EFFECT: reduced chlorine content in product up to 0.01 %, 1 ex, 1 tbl

Description

 The invention relates to the field of salts, in particular the production of cobalt carbonate.

 A known method (Scherbina K.G., Oratovsky V.I., Kozlova S.V., autoswitch N 684003, class C 01 G 51/06, 1975) for the production of cobalt carbon by dissolving cobalt metal in ammonia-carbonate solution, followed by decomposition of the ammonium-carbonate complex of bivalent cobalt with a gas mixture containing carbon dioxide, separation of the precipitate, washing and drying it. This method allows to obtain cobalt carbonate with an arbitrarily low chlorine content, since it uses reagents known to be free of chlorine.

 However, this method is not applicable directly to obtain cobalt carbonate from a solution of cobalt chloride. Its use requires preliminary preparation by known methods (for example, by electrolysis) of cobalt metal from a solution of cobalt chloride.

 There is also a method (Karyakin Yu.V., Angelov NI. Pure chemicals. M: Chemistry, 1973, p. 213) for producing cobalt carbonate by precipitation by pouring a solution of sodium hydrogen carbonate into a solution of cobalt nitrate. This method has the same drawback as described above: the impossibility of direct use to obtain cobalt carbonate from chloride solutions, since the conversion of cobalt from the chloride form to nitrate is required first.

 A known method of producing cobalt (II) carbonate (Karyakin Yu.V., Angelov N.I. Pure chemicals. M: Chemistry, 1973, p. 213), consisting in the fact that the deposition is carried out by pouring a solution of precipitant (sodium carbonate ) into a solution of cobalt chloride, followed by separation, washing and drying of the precipitate.

 A disadvantage of the known method for producing cobalt carbonate is that the resulting product contains a significant amount of chlorine ion.

 Closest to the claimed solution is a method (N.S. Starck GmbH & Co. KG, DE 19619235, class C 01 G 51/00, 11/28/96), in which, to obtain cobalt carbonate, solutions of cobalt chloride and sodium bicarbonate are mixed, separated precipitate, washed and dried. The process is conducted in a continuously operating reactor while feeding cobalt and precipitant solutions.

 The disadvantage of this method is that the obtained and thoroughly washed precipitate of cobalt carbonate contains a significant amount of chlorine ion (at least 0.2%).

 The invention is aimed at obtaining cobalt carbonate from chloride with a chlorine content of not more than 0.01% (which is significantly lower than the level of chlorine obtained in accordance with the prototype).

 Unlike the prototype, in our proposed method, a solution of cobalt chloride is poured into a solution of an alkali metal or ammonium bicarbonate precipitator, and at the beginning of the process, the reaction proceeds against the background of an excess of precipitant, with a further decrease in the precipitator concentration until the precipitation reaction is completed.

 Obtained earlier cobalt carbonate particles are a “seed” for subsequent formed particles, which provides the desired cobalt carbonate structure.

 Examples of the method.

Obtaining cobalt carbonate was carried out in a glass beaker with a stirrer, in which at the beginning one of the solutions was poured: precipitant (option 1) or cobalt chloride (option 2), after which, while stirring with a thin stream, the second solution (cobalt chloride for option 1 or precipitant for option 2). Option 3 - at the same time fill in solutions of cobalt chloride and precipitant. To improve the filterability of the suspension of the resulting carbonate, the temperature was maintained in the range 55-65 ^o C. The resulting precipitate was filtered, washed 10 times with distilled water (by repulpation at T: W = 1: 15 and filtration) and dried at 60 ^o C.

 The results of the experiments are shown in the table.

 As can be seen from the table, the smallest chlorine content in the product is achieved with the first option: the gulf of cobalt chloride in the precipitator solution, i.e. technical result achieved.

Option 2 - pouring the precipitant solution into the cobalt chloride solution;
Option 3 - at the same time fill in solutions of cobalt chloride and precipitant.

Claims (1)

 A method for producing cobalt carbonate from a chloride solution, comprising mixing a cobalt chloride solution with a solution of an alkali metal or ammonium hydrogen carbonate salt, separating the precipitate, washing it with water and drying, characterized in that the cobalt chloride solution is poured into an alkali metal or ammonium hydrogen carbonate solution.

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