초록 ▼

A countercurrent, cooling crystallization and purification method for a multi-component molten mixture wherein the mixture is treated by a purification system comprising one or more crystallizers (1A, 1B) each having, at the respective upper portion, a clarifying portion (10A, 10B) and a purifier (2

A countercurrent, cooling crystallization and purification method for a multi-component molten mixture wherein the mixture is treated by a purification system comprising one or more crystallizers (1A, 1B) each having, at the respective upper portion, a clarifying portion (10A, 10B) and a purifier (2) arranged in series to the crystallizer or crystallizers and having, at its upper portion, a clarifying portion (20), the crystallizer or crystallizers and the purifier having a temperature difference therebetween and disposed in the order of temperature. The starting mixture is fed to one of the crystallizers and subjected to crystallization there, and the resulting crystals are taken out from the bottom of the crystallizer and fed to another crystallizer or a purifier of higher temperature while the clarified liquid, i.e., mother liquor positioned at the clarifying portion of the crystallizer is led to another crystallizer of lower temperature or discharged out of the system. In each of the crystallizers and purifier, the crystals are moved downwardly while the mother liquor is moved upwardly to effect countercurrent contact with the mother liquor. Through this countercurrent contact of the crystals with the mother liquor of higher temperature, the crystals are purified by being washed with the mother liquor. With this arrangement, the purification of the mixture can be attained effectively and at a reasonable cost.

대표청구항 ▼

In a countercurrent, cooling crystallization and purification method for a multi-component molten mixture for separating a component of the mixture, wherein the purification of the molten mixture is effected by countercurrent contact of crystals formed with a mother liquor, wherein the improvement c

In a countercurrent, cooling crystallization and purification method for a multi-component molten mixture for separating a component of the mixture, wherein the purification of the molten mixture is effected by countercurrent contact of crystals formed with a mother liquor, wherein the improvement comprises, in a system comprising a cooling type crystallizer having, at its upper portion, a clarifying portion containing a liquid and a vertical purifier having, at its upper portion, a clarifying portion and, at its lower portion, heating means, and the contents of said purifier are at a temperature higher than the contents of said crystallizer, feeding said molten mixture into the crystallizer, feeding crystals formed in the crystallizer to the clarifying portion of the purifier, allowing the crystals in the clarifying portion of the purifier to move downwardly therein and melting said crystals by said heating means, withdrawing a portion of the resulting melt as a product and allowing the remainder of said melt to move upwardly in said purifier as a reflux to wash the descending crystals, and feeding the clarified liquid from the clarifying portion of the purifier directly to the liquid in the clarifying portion of the crystallizer in which the crystallization is carried out at a temperature lower than the operation temperature of the purifier so that crystals formed in the crystallizer are washed and the clarified liquid fed from the purifier is cooled by the liquid of a lower temperature in the crystallizer to be recrystallized.