Method for separating durene by freezing crystallization

Abstract

The invention discloses a method for separating durene by freezing crystallization and relates to the technical field of industrial production of centrifugal separation and crystallization of durene from solution of durene. In the method, durene-containing solution is frozen to the temperature of between 15 below zero and 5 DEG C and is introduced into a centrifugal machine; and the method is characterized by comprising the following steps of: adjusting the rotating speed of the centrifugal machine to be 800 revolutions per minute, and stopping introducing the durene-containing solution into the centrifugal machine when the thickness of a filter cake in the centrifugal machine is 2 to 15 mm; and adjusting the rotating speed of the centrifugal machine to be 1,200 revolutions per minute, recovering the thrown liquid phase and taking a solid phase. The mass percentage concentration of the durene in the thrown liquid phase is only 7.5 percent when the rotating speed of the centrifugal machine is 800 revolutions per minute, while the mass percentage concentration of the durene in the thrown liquid phase is 16 percent when the rotating speed of the centrifugal machine is improved to 800 revolutions per minute; and the liquid phase can be recovered for freezing crystallization. The method can improve the yield of the durene to 60 percent.

Description

technical field

[0001] The invention relates to the technical field of industrial production for centrifugally separating and crystallizing durene from a durene solution. Background technique

[0002] The existing durene centrifugal separation and crystallization method is to place the durene-containing mother liquor in a centrifuge with a rotating speed of 1200 rpm for separation. At this time, the mass percent concentration of durene in the liquid is still 11% %, while the yield of durene is only 42%. Contents of the invention

[0003] The purpose of the present invention is to propose a method for improving the yield of durene by freezing crystallization and separating durene.

[0004] In the present invention, the solution containing durene is frozen to -15-5°C and then passed into the centrifuge, which is characterized in that the rotating speed of the centrifuge is adjusted to 800 rpm, and when the thickness of the filter cake in the centrifuge is 2-15mm, the centri...