ENHANCED SETTLING AND DEWATERING OF OIL SANDS MATURE FINE TAILINGS WITH TITANOMAGNETITE NANOPARTICLES GRAFTED WITH POLYACRYLAMIDE AND LAURYL SULFATE
Nanoflocculants are provided that are comprised of nanoparticles of titanomagnetite having anionic surface moieties associated with electrostatically bound polymerized chains of cationic polyacrylamide, further comprising lauryl sulfate moieties adsorbed to the surface of nanoparticles of the titanomagnetite nanoparticles and/or adsorbed to the bound cationic polyacrylamide polymers. These nanoflocculants combine the dual functionalities of the polyacrylamide/lauryl sulfate moieties, as well as the surface activity of titanomagnetite nanomaterials. Process are provided for making and using the disclosed nanoflocculants, including uses for flocculating intimate aqueous dispersions of solids and bitumen.
1 . A process of making a flocculating agent, comprising:
forming a titanomagnetite nanoparticle, the method comprising:
contacting (NH 4 ) 2 Fe(SO 4 ) 2 ·6H 2 O with TiCl 4 to form a titanomagnetite compound;
contacting the titanomagnetite compound with an aqueous solution to form a hydroxyl group on a surface of the titanomagnetite compound;
deprotonating the hydroxyl group to negatively charge the surface of the titanomagnetite compound;
contacting the titanomagnetite compound with acrylamide; and
contacting the titanomagnetite compound with sodium dodecyl sulfate to form a titanomagnetite nanoparticle.
2 . The process of claim 1 further comprising contacting the acrylamide with the sodium dodecyl sulfate.
3 . The process of claim 1 further comprising polymerizing the acrylamide to form polyacrylamide.
4 . The process of claim 1 further comprising contacting the polyacrylamide with the sodium dodecyl sulfate.
5 . The process of claim 1 further comprising contacting the titanomagnetite compound with HNO 3 to form acrylamide with a protonated amine group.
6 . The process of claim 2 further comprising associating the acrylamide with a protonated amine group with the surface of the titanomagnetite compound.
7 . The process of claim 2 further comprising generating primary radicals on the surface of the titanomagnetite compound.
8 . The process of claim 1 further comprising contacting (NH 4 ) 2 Fe(SO 4 ) 2 ·6H 2 O with an oxidizing agent.
9 . The process of claim 1 further comprising contacting the acrylamide with ammonium persulfate.
10 . The process of claim 1 further comprising adjusting the pH of the aqueous solution to above 3.
11 . A method for deflocculating a process stream, the method comprising:
contacting the process stream with a deflocculating agent, the deflocculating agent comprising:
a metal oxide nanoparticle comprising a surface;
said surface comprising a negative charge;
acrylamide; and
sodium lauryl sulfate.
12 . The method of claim 11 wherein the initial settling rate of the process stream is at least 4.2 centimeters per second.
13 . The method of claim 11 further comprising decreasing the turbidity of the process stream.
14 . The method of claim 11 further comprising consolidating the process stream.
15 . The method of claim 11 further comprising dewatering the process stream.
16 . The method of claim 11 wherein the metal oxide nanoparticle comprises titanomagnetite.
17 . The method of claim 11 wherein the process stream comprises tailings waste.