CS260441B1 - A method for producing magnesium compounds with low solubility - Google Patents

Abstract

A raw material containing sodium cation and bicarbonate or/and carbonate or/and hydroxyl anion, an acid containing an anion appropriate for the production of the desired salt and magnesium chloride are reacted. The resulting precipitate is separated and processed into a product, while the remaining solution containing sodium chloride and/or the resulting carbon dioxide is partially or completely returned to the production of soda. The product is suitable for use in the cosmetics industry.

Description

The invention relates to a process for the production of magnesium compounds with low solubility.

For the sake of simplicity, the widespread methods of the aforementioned pure products are precipitation processes.

The disadvantage of these processes is that by-products are difficult to process. This disadvantage is overcome by the process according to the invention for the preparation of low-solubility magnesium compounds or mixtures thereof, which comprises reacting a sodium cation-containing feedstock and a bicarbonate and / or carbonate and / or hydroxylic acid anion-containing acid suitable for the production salts and magnesium chloride in the form of a solution or suspension or solid salt or hydrate, the resulting precipitate is separated and processed to the product, the remaining solution containing predominantly sodium chloride and / or the resulting carbon dioxide being partially or completely returned to the soda production.

When using an excess of an acid containing anion to produce the desired salt, the solution remaining after separation of the precipitate partially or completely returns to the manufacturing process.

Preferably, a solution resulting from the production of pure sodium carbonate and / or any of its hydrates and / or pure sodium bicarbonate, or mixtures thereof, is used as the raw material containing sodium cation and anionic bicarbonate and / or carbonate.

The basic effect of the process according to the invention is that by incorporating the production of magnesium compounds into the sodium complex, waste-free technology is achieved. Furthermore, sodium chloride is saved in the production of soda. As a result, the production method according to the invention becomes more economical than the previously known production methods.

The manufacture may be continuous, discontinuous or a combination of both. For example, the mother liquor from the production of pure sodium bicarbonate and the acid containing anion suitable for the production of a sparingly soluble salt are reacted. The desired magnesium salt is further precipitated by the addition of a magnesium chloride solution. The resulting precipitate is collected, for example by filtration or centrifugation, washed and worked up to the desired product. The wash water can be incorporated into the production cycle. The remaining solution mainly contains sodium chloride and / or the resulting carbon dioxide is partially or completely returned to the soda production.

The production method according to the invention is described in more detail below with reference to a specific embodiment.

An example liter of mother liquor from the production of pure pharmacopoeial sodium bicarbonate was transferred in a batch stirred reactor with an appropriate amount of 75% by weight of phosphoric acid. to a sodium hydrogen phosphate solution. This was further added by adding a 15 wt.% Magnesium chloride solution. at 80 ° C was converted to a precipitate of dibasic magnesium phosphate trihydrate, which was separated from the resulting suspension by filtration, washed and dried at 60 ° C. The remaining sodium chloride-containing solution is suitable after saturation for use in the production of soda by the ammonia process.

The product obtained can be used in the cosmetic industry.

Claims (3)

Subject 1. A process for the preparation of low-solubility magnesium compounds or mixtures thereof, comprising reacting a feedstock containing sodium cation and a bicarbonate and / or carbonate and / or hydroxyl anion, an anion-containing acid appropriate for the production of the desired salt and magnesium chloride in in the form of a solution or a suspension or a solid salt or a hydrate, the resulting precipitate is collected and processed to give the product, the remaining solution containing mainly sodium chloride and / or the resulting carbon dioxide being partly or completely returned to the soda production. vynalezu 2. A process according to claim 1, characterized in that, when an excess of an anion-containing acid is used to produce the desired salt, the solution remaining after separation of the precipitate is partially or completely returned to the manufacturing process. 3. Process according to claim 1, characterized in that a solution resulting from the production of pure sodium carbonate and / or any of its hydrates and / or pure sodium bicarbonate, or a solution thereof, is used as the raw material containing sodium cation and anionic bicarbonate and / or carbonate. mutual mixtures.