IMPROVEMENT OF CRYSTAL REFINING TECHNOLOGIES BY CONTROLLED CRYSTALLIZATION

摘要

A method is provided for making large, uniform and individual crystals from aqueous solutions including the steps of obtaining a concentrated aqueous solution b y means of evaporation; rapidly cooling the solution from a post-evaporation high temperature to a first lower temperature, wherein the first lower temperature is lower than the pos t- evaporation high temperature and further wherein the first lower temperature is an isothermal crystallization temperature of said solution; generating a batch of initial nuclei by induci ng nucleation at the first lower temperature and starting crystal growth; uniformly spreading the initial nuclei into a bulk solution; maintaining simultaneous and rapid growth of crystals from th e nuclei at the first lower temperature for a predetermined length of time; continuing the growth of the crystals to produce large, uniform and individual crystals for a predetermined length of time at a temperature that varies gradually from between a first lower temperature to a second lower temperature, wherein the second lower temperature is a temperature lower tha n the first lower temperature and further wherein the second lower temperature is an end temperature of crystallization; and recovering the large, uniform and individual crystals. Parameters and a system for producing lactose monohydrate crystals using the method are also provided.