Liquid purification or separation – Processes – Making an insoluble substance or accreting suspended...
Reexamination Certificate
2005-02-15
2005-02-15
Hruskoci, Peter A. (Department: 1724)
Liquid purification or separation
Processes
Making an insoluble substance or accreting suspended...
C034S338000, C044S626000, C209S005000, C210S728000, C210S729000, C210S732000, C210S770000, C210S778000
Reexamination Certificate
active
06855260
ABSTRACT:
A new method of improving the process of dewatering fine particulate materials is disclosed. In this method, an aqueous slurry of fine particles is treated with appropriate hydrophobizing reagents so that the particulate material becomes moderately hydrophobic with its water contact angle considerably below 90°. A low hydrophile-lipophile balance (HLB) number surfactant is then added to the slurry, so that the surfactant molecules adsorb on the moderately hydrophobic surface primarily by hydrophobic attraction and, thereby, increase its contact angle close to or above 90°. By virtue of the greatly enhanced hydrophobicity, the water molecules adhering to the surface are destabilized and removed more readily by a mechanical dewatering process. Any nonionic surfactant with its HLB number below about 15 may be used for the hydrophobicity enhancement. The surfactants may be used in conjunction with appropriate solvents such as light hydrocarbon oils and short-chain alcohols. The moisture reduction can be further improved by using appropriate electrolytes in conjunction with the low HLB surfactants, spraying surface tension lowering reagents onto the filter cake, subjecting the cake to a suitable vibratory means, and by using combinations thereof.
REFERENCES:
patent: 1064723 (1913-06-01), Greenway et al.
patent: 1102873 (1914-07-01), Chapman et al.
patent: 1208171 (1916-12-01), Lavers et al.
patent: 2120217 (1938-06-01), Harris
patent: 2864765 (1958-12-01), Stoneman et al.
patent: 3880824 (1975-04-01), Rao et al.
patent: 4039466 (1977-08-01), Matsuda et al.
patent: 4156649 (1979-05-01), Quinn et al.
patent: 4191655 (1980-03-01), Quinn et al.
patent: 4206063 (1980-06-01), Wang et al.
patent: 4207186 (1980-06-01), Wang et al.
patent: 4210531 (1980-07-01), Wang et al.
patent: 4278208 (1981-07-01), Falcon-Steward
patent: 4410431 (1983-10-01), Roe
patent: 4447344 (1984-05-01), Roe
patent: 4507198 (1985-03-01), Unger et al.
patent: 4561953 (1985-12-01), Muralidhara et al.
patent: 4770766 (1988-09-01), Keller, Jr. et al.
patent: 4866856 (1989-09-01), Feeley
patent: 4909946 (1990-03-01), Sanner
patent: 4969928 (1990-11-01), Wen et al.
patent: 5011612 (1991-04-01), Keeney
patent: 5048199 (1991-09-01), Cole
patent: 5161694 (1992-11-01), Yoon et al.
patent: 5167831 (1992-12-01), Diamas
patent: 5215669 (1993-06-01), Koester et al.
patent: 5256169 (1993-10-01), Roe
patent: 5283322 (1994-02-01), Martin et al.
patent: 5346630 (1994-09-01), Kenney
patent: 5379902 (1995-01-01), Wen et al.
patent: 5405554 (1995-04-01), Neff et al.
patent: 5458786 (1995-10-01), Yoon et al.
patent: 5520822 (1996-05-01), Sun
patent: 5544760 (1996-08-01), Benn et al.
patent: 5587085 (1996-12-01), Yoon et al.
patent: 5587786 (1996-12-01), Champagne et al.
patent: 5603841 (1997-02-01), Kerr
patent: 5670056 (1997-09-01), Yoon et al.
patent: 5700904 (1997-12-01), Baker et al.
patent: 5814210 (1998-09-01), Yoon et al.
patent: 6375853 (2002-04-01), Yoon
patent: 6526675 (2003-03-01), Yoon
patent: WO9725149 (1997-07-01), None
patent: WO0009268 (2000-02-01), None
Brooks and Bethel, “Zeta Potential, Contact Angle and the Use of Amines in the Chemical Dewatering of Fine-Floated Coal,” Powder Technology, vol. 40, pp. 207-214, 1984.
Groppo, J.G. and Parekh, B.K., “Surface Chemical Control of Ultra-Fine Coal to Improve Dewatering,” Coal Preparation, vol. 17, pp. 103-116, 1996.
Meenan, G.F., “Fine Coal Dewatering Equipment,” Proceedings of the Industrial Practice of Fine Coal Processing, R.R. Klimpel and P.T. Luckie, eds., Society of Mining Engineers, Inc., pp. 223-229, 1988.
Singh, B.P., “The Influence of Surface Phenomena on the Dewatering of Fine Clean Coal,” Filtration and Separation, pp. 159-163, Mar., 1977.
Smith, R.W., “Coadsorption of Dodecylamine Ion and Molecule on Quartz,” Transactions of Americal Institute of Mining Engineers, vol. 266, pp. 427-433, 1963.
Yoon and Ravishankar, “Long-Range Hydrophobic Forces between Mica Surfaces in Dodecylammonium Chloride Solutions in the Presence of Dodecanol,” J. Colloid and Interface Science, vol. 179, pp. 391-402, 1996.
Roe-Hoan Yoon and S.A. Ravishankar, “Long-Range Hydrophobic Forces between Mica Surfaces in Alkaline Dodecylammonium Chloride Solutions” 1996, Journal of Colloid and Interfaces Science, 179, pp. 403-411.
Laiqun Mao and Roe-Hoan Yoon, “Predicting flotation rates using a rate equation derived from first principles” 1997, International Journal of Mineral Processing, 51, pp. 171-181.
Roe-Hoan Yoon, Darrin H. Flinn and Yakov I. Rabinovich, “Hydrophobic Interactions between Dissimilar Surfaces” 1997, Journal of Colloid and Interface Science, 185, pp. 363-370.
Grossman Tucker Perreault & Pfleger PLLC
Hruskoci Peter A.
LandOfFree
Methods of enhancing fine particle dewatering does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Methods of enhancing fine particle dewatering, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Methods of enhancing fine particle dewatering will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-3507817