Editing Crystallization (section)

===Size distribution===
{{Unreferenced section|date=July 2017}}

The appearance and size range of a crystalline product is extremely important in crystallization. If further processing of the crystals is desired, large crystals with uniform size are important for washing, filtering, transportation, and storage, because large crystals are easier to filter out of a solution than small crystals.<ref>{{Cite journal |last1=Beck |first1=Ralf |last2=Häkkinen |first2=Antti |last3=Malthe-Sørenssen |first3=Didrik |last4=Andreassen |first4=Jens-Petter |date=2009-05-07 |title=The effect of crystallization conditions, crystal morphology and size on pressure filtration of l-glutamic acid and an aromatic amine |url=https://linkinghub.elsevier.com/retrieve/pii/S1383586609000355 |journal=Separation and Purification Technology |volume=66 |issue=3 |pages=549–558 |doi=10.1016/j.seppur.2009.01.018 |issn=1383-5866|url-access=subscription }}</ref> Also, larger crystals have a smaller surface area to volume ratio, leading to a higher purity. This higher purity is due to less retention of [[mother liquor]] which contains impurities, and a smaller loss of yield when the crystals are washed to remove the mother liquor. In special cases, for example during drug manufacturing in the pharmaceutical industry, small crystal sizes are often desired to improve drug dissolution rate and bio-availability. The theoretical crystal size distribution can be estimated as a function of operating conditions with a fairly complicated mathematical process called population balance theory (using [[population balance equation]]s).