| 摘要 |
PURPOSE:To efficiently separate ice in a short time and to prevent a decrease in the low-m.p. components such as aromatic compds. by freezing an aq. soln., keeping the frozen material under reduced pressure for a specified time. CONSTITUTION:An aq. soln. is froze and the solute is melted out directly from the frozen material or after the material is crushed. The frozen material is kept under reduced pressure at a temp. at which ice is not melted for the time necessary for growing the ice crystal or hardening the ice and then the ice is separated. Consequently, ice can be easily separated and a concd. liq. can be obtained in good yield in a short time. When an aq. soln. contg. liq. components unstable to heat, low-b.p. components or frothing components is concentrated, the soln. can be concentrated without deteriorating the quality.
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