Patent ID: 9371242
Filing Date: 2016-06-21
CPC Classification: B01D,C02F

Claim Text:
1. Process for the recovery or removal of one or more crystallizable compounds from an aqueous solution containing, apart from the said crystallizable compounds, one or more organic or inorganic scale-forming or scale-inducing materials having a lower solubility in water than the said crystallizable compounds, wherein the said scale-forming or scale-inducing material is selected from the group of salts, oxides and hydroxides of calcium, barium, magnesium, aluminum, and iron, said process comprising: subjecting the said aqueous solution to a reverse osmosis step and the retentate thereof is subjected to at least one eutectic freeze crystallization step with recovery of ice and said one or more crystallizable compounds in crystalline form, wherein the said scale-forming or scale-inducing materials are present in the said eutectic freeze crystallization step in a supersaturated, meta stable condition, wherein said at least one eutectic freeze crystallization step results in three streams, an ice stream, a salt stream including the one or more crystallizable compounds, and a mother liquor including the scale-forming or scale-inducing materials; subjecting at least part of the mother liquor to a treatment with seed crystals for said scale-forming or scale-inducing materials thereby inducing precipitation of said scale-forming or scale-inducing materials, forming a treated mother liquor; removing at least part of the precipitated solid material obtained with said seed crystals from said treated mother liquor; and subsequently recycling said treated mother liquor to the at least one eutectic freeze crystallization step or to the feed thereto.