Method for adsorbing substances using silica adsorbent on magnetic substrate
AssigneeW. R. Grace & Co.-Conn.
InventorsJames Neil Pryor, Linda Lee Crump
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Abstract
Method for Absorbing substances wherein adsorbent particles comprising superparamagnetic and/or low Curie Temperature transition metal-containing cores surrounded by a hydrous siliceous oxide coating can be formed by an aqueous process wherein the core is precipitated from an aqueous solution and a siliceous oxide coating is deposited thereon while complete drying of the core is avoided until after the siliceous oxide is deposited. The resulting siliceous adsorbents exhibit strong superparamagnetic and/or low Curie temperature magnetic properties with low transition metal leachability.
Claims5
A method for adsorbing macromolecules from a liquid, the method comprising:
- (a) dispersing into the liquid a particulate adsorbent comprising particles comprising:
- (i) at least one core consisting essentially of a transition metal-containing component selected from the group consisting of superparamagnetic materials, low Curie Temperature materials, and mixtures thereof, and
- (ii) a siliceous oxide coating on the surface of said core(s), wherein said coating covers the entire surface of said core(s) such that said adsorbent particles have a transition metal leach value when present as 0.33 g dried adsorbent particles in 20 ml of 1N hydrochloric acid aqueous solution for 15 minutes of less than about 50 ppm metal based on the weight of said solution;
- (b) providing conditions in the liquid such that adsorption of the macromolecules onto the particulate takes place;
- (c) removing the particulate adsorbent and adsorbed macromolecules from the liquid, and
- (d) recovering the adsorbed macromolecules from the particulate adsorbent.
Dependencies are inferred from the claim text.