A method of treating brines (10) comprising the steps of: pre-cooling the brines using a stream medium before further cooling the brines using a refrigerant. This further cooling of the brines continues until a first temperature equal to a eutectic freezing point of a mineral salt suspended in the brines is reached, such that the brines are transformed into an ice slurry. The ice is then separated from the ice slurry for use as part of the pre-cooling step. The remainder of the ice slurry is filtered to recover crystallised mineral salts suspended therein. A system for performing the method is also described.

A method of treating brines (10) comprising the steps of: pre-cooling the brines using a stream medium before further cooling the brines using a refrigerant. This further cooling of the brines continues until a first temperature equal to a eutectic freezing point of a mineral salt suspended in the brines is reached, such that the brines are transformed into an ice slurry. The ice is then separated from the ice slurry for use as part of the pre-cooling step. The remainder of the ice slurry is filtered to recover crystallised mineral salts suspended therein. A system for performing the method is also described.

An ion removing system having an ion removing apparatus that includes a fine bubble generating part generating fine bubbles and that causes the fine bubbles to adsorb metal ions to remove the metal ions from the hard water due to supply the fine bubbles generated by the fine bubble generating part into the hard water. In addition, the ion removing system includes a primary-side flow path to supply the hard water to the ion removing apparatus, a separating apparatus that separates crystals of a metal component deposited by crystallizing the metal ions removed from the hard water by the ion removing apparatus, and a secondary-side flow path that takes out, from the separating apparatus, treated water obtained by separating the crystals. The primary-side flow path is provided with a supply-side backflow prevention mechanism.

A method for precipitating as particles 2,6-diamino-3,5-dinitropyrazine-1-oxide (or ANPZO) present in an acid medium, which comprises adding the acid medium to an aqueous solution and which is characterized in that the aqueous solution comprises a nitrate salt. Further disclosed is a method for synthesizing ANPZO implementing this precipitation method. The synthesis method comprises converting 2,6-diaminopyrazine-1-oxide (or DAPO) into ANPZO by nitration in an acid medium, and then precipitating as particles the ANPZO by adding the acid medium to an aqueous solution, and is characterized in that the aqueous solution comprises a nitrate salt.

The present invention aims to provide a compound purification apparatus capable of providing a high purity compound in high yield and at low cost. The present invention relates to an apparatus for purifying a compound, the purification apparatus including: a crystallizing unit including a crystal forming section; and a wash column including a mechanism that forcibly transfers crystals, the crystallizing unit including N tanks connected in series, wherein N is 2 or greater, a 1st tank is a most downstream tank, a (N)th tank is a most upstream tank, at least the 1st tank is a crystallization tank including a cooling mechanism, and a 2nd and subsequent tanks are each a crystallization tank or a ripening tank, the purification apparatus including a line that feeds a compound-containing liquid to be purified to at least one of the N tanks, the wash column including: a line that sends a product out; and a line that returns a mother liquor to the crystallizing unit, with the line that returns a mother liquor to the crystallizing unit being connected to at least the (N)th tank, the crystallizing unit including: a line that feeds a slurry from the (N)th tank to the wash column; a line that sends a slurry from a tank among the 1st to (N1)th tanks to the next upstream tank; and a line that is provided to each of the 1st to (N1)th tanks and that sends thereto a mother liquor withdrawn from an upstream tank, wherein at least one of the lines that send a slurry from a tank among the 1st to (N1)th tanks to the next upstream tank is a line that sends a slurry from a tank to the next upstream tank via a solid-liquid separator and that has a line that returns a mother liquor from which crystals are removed in the solid-liquid separator to the tank where the slurry came from, and wherein the line that is provided to each of the 1st to (N1)th tanks and that sends thereto a mother liquor withdrawn from an upstream tank is a line that directly sends a mother liquor withdrawn from a tank one upstream or a line that sends a mother liquor withdrawn from a tank one upstream via a solid-liquid separator, the purification apparatus further including a line that sends a mother liquor to the outside of the purification apparatus.

The present invention aims to provide a compound purification apparatus capable of providing a high purity compound in high yield and at low cost. The present invention relates to an apparatus for purifying a compound, the purification apparatus including: a crystallizing unit including a crystal forming section; and a wash column including a mechanism that forcibly transfers crystals, the crystallizing unit including N tanks connected in series, wherein N is 2 or greater, a 1st tank is a most downstream tank, a (N)th tank is a most upstream tank, at least the 1st tank is a crystallization tank including a cooling mechanism, and a 2nd and subsequent tanks are each a crystallization tank or a ripening tank, the purification apparatus including a line that feeds a compound-containing liquid to be purified to at least one of the N tanks, the wash column including: a line that sends a product out; and a line that returns a mother liquor to the crystallizing unit, with the line that returns a mother liquor to the crystallizing unit being connected to at least the (N)th tank, the crystallizing unit including: a line that feeds a slurry from the (N)th tank to the wash column; a line that sends a slurry from a tank among the 1st to (N1)th tanks to the next upstream tank; and a line that is provided to each of the 1st to (N1)th tanks and that sends thereto a mother liquor withdrawn from an upstream tank, wherein at least one of the lines that send a slurry from a tank among the 1st to (N1)th tanks to the next upstream tank is a line that sends a slurry from a tank to the next upstream tank via a solid-liquid separator and that has a line that returns a mother liquor from which crystals are removed in the solid-liquid separator to the tank where the slurry came from, and wherein the line that is provided to each of the 1st to (N1)th tanks and that sends thereto a mother liquor withdrawn from an upstream tank is a line that directly sends a mother liquor withdrawn from a tank one upstream or a line that sends a mother liquor withdrawn from a tank one upstream via a solid-liquid separator, the purification apparatus further including a line that sends a mother liquor to the outside of the purification apparatus.

A method for precipitating as particles 2,6-diamino-3,5-dinitropyrazine-1-oxide (or ANPZO) present in an acid medium, which comprises adding the acid medium to an aqueous solution and which is characterized in that the aqueous solution comprises a nitrate salt. Further disclosed is a method for synthesizing ANPZO implementing this precipitation method. The synthesis method comprises converting 2,6-diaminopyrazine-1-oxide (or DAPO) into ANPZO by nitration in an acid medium, and then precipitating as particles the ANPZO by adding the acid medium to an aqueous solution, and is characterized in that the aqueous solution comprises a nitrate salt.

An ion removing system having an ion removing apparatus that includes a fine bubble generating part generating fine bubbles and that causes the fine bubbles to adsorb metal ions to remove the metal ions from the hard water due to supply the fine bubbles generated by the fine bubble generating part into the hard water. In addition, the ion removing system includes a primary-side flow path to supply the hard water to the ion removing apparatus, a separating apparatus that separates crystals of a metal component deposited by crystallizing the metal ions removed from the hard water by the ion removing apparatus, and a secondary-side flow path that takes out, from the separating apparatus, treated water obtained by separating the crystals. The primary-side flow path is provided with a supply-side backflow prevention mechanism.

Provided are sodium hypochlorite pentahydrate crystal gains that have high bulk density and increase bulk density in a container and improve transport efficiency by controlling the shape of the sodium hypochlorite pentahydrate crystals, and a production method thereof.

As a result of stirring or circulating by pump an aqueous solution of sodium hypochlorite pentahydrate in a crystallization tank in a crystallization step, sodium hypochlorite pentahydrate crystal grains are obtained having an average aspect ratio of 2.5 or less.

Provided are sodium hypochlorite pentahydrate crystal gains that have high bulk density and increase bulk density in a container and improve transport efficiency by controlling the shape of the sodium hypochlorite pentahydrate crystals, and a production method thereof.

As a result of stirring or circulating by pump an aqueous solution of sodium hypochlorite pentahydrate in a crystallization tank in a crystallization step, sodium hypochlorite pentahydrate crystal grains are obtained having an average aspect ratio of 2.5 or less.