Virginia Tech Intellectual Properties Inc

Other

Virginia Polytechnic Institute and State University

Center for Innovative Technology

Mineral and Coal Technologies, Inc.

Thiele Kaolin Company

Yoon, Roe-hoan

Roe-Hoan Yoon

Gerald H Luttrell

Gregory T Adel

Mert Kerem Eraydin

Demetri Telionis

Yihong Yang

Sanja Miskovic

Aaron Noble

Abdel-Halim Said

Nikhil Gupta

Saad Ragab

Dmitri L Kouznetsov

Eric S Yan

Kerem Eraydin

Cesar Indiongco Basilio

Thomas M Hilderbrand

A Dilo Paul

Chad Freeland

Ramazan Asmatulu

Oh-Hyung Han

Byung-Wook Park

Gerald Luttrell

Hydrophobic particles such as coal and hydrophobized mineral fines can be readily separated from hydrophilic impurities by forming agglomerates in water using a hydrophobic liquids such as oil. The agglomerates of hydrophobic particles usually entrap large amounts of water, causing the moisture of the recovered hydrophobic particles to be excessively high. This problem can be overcome by dispersing the hydrophobic agglomerates in a hydrophobic liquid that can be readily recycled. The dispersion can be achieved using specially designed apparatus and methods that can create a turbulence that can help destabilize the agglomerates in a recyclable hydrophobic liquid and facilitate the dispersion.

Method for dewatering and demineralization of fine particles

Fine coal is cleaned of its mineral matter impurities and dewatered by mixing the aqueous slurry containing both with a hydrophobic liquid, subjecting the mixture to a phase separation. The resulting hydrophobic liquid phase contains coal particles free of surface moisture and droplets of water stabilized by coal particles, while the aqueous phase contains the mineral matter. By separating the entrained water droplets from the coal particles mechanically, a clean coal product of substantially reduced mineral matter and moisture contents is obtained. The spent hydrophobic liquid is separated from the clean coal product and recycled. The process can also be used to separate one type of hydrophilic particles from another by selectively hydrophobizing one.

Cleaning and dewatering fine coal

A process for cleaning and dewatering hydrophobic particulate materials is presented. The process is performed in two steps: 1) agglomeration of the hydrophobic particles in a first hydrophobic liquid/aqueous mixture; followed by 2) dispersion of the agglomerates in a second hydrophobic liquid to release the water trapped within the agglomerates along with the entrained hydrophilic particles.

Methods for separating and dewatering fine particles

Apparatus for dewatering and demineralization of fine particles

A process for cleaning and dewatering hydrophobic particulate materials is presented. The process is performed in in two steps: 1) agglomeration of the hydrophobic particles in a first hydrophobic liquid/aqueous mixture; followed by 2) dispersion of the agglomerates in a second hydrophobic liquid to release the water trapped within the agglomerates along with the entrained hydrophilic particles.

Method of separating and de-watering fine particles

Methods of increasing the rate of separating hydrophobic and hydrophilic particles by flotation have been developed. They are based on using appropriate reagents to enhance the hydrophobicity of the particles to be floated, so that they can be more readily collected by the air bubbles used in flotation. The hydrophobicity-enhancing reagents include low HLB surfactants, naturally occurring lipids, modified lipids, and hydrophobic polymers. These methods can greatly increase the rate of flotation for the particles that are usually difficult to float, such as ultrafine particles, coarse particles, middlings, and the particles that do not readily float in the water containing large amounts of ions derived from the particles. In addition, new collectos for the flotation of phosphate minerals are disclosed.

Methods of increasing flotation rate

A rotor for flotation machines or flotation cells of flotation machines includes blades that are configured to provide improved bubble flow and bubble generation performance while also reducing the power requirements for rotating the rotor to generate bubble flow within a tank of a flotation cell used to generate froth. Embodiments of the rotor may also be configured to be smaller than conventional rotor designs, which may help reduce the costs of manufacturing the rotor or flotation machines using such embodiments of the rotor.

Flotation machine rotor

Methods of increasing the rate of separating hydrophobic and hydrophilic particles by flotation have been developed. They are based on using appropriate reagents to enhance the hydrophobicity of the particles to be floated, so that they can be more readily collected by the air bubbles used in flotation. The hydrophobicity-enhancing reagents include low HLB surfactants, naturally occurring lipids, modified lipids, and hydrophobic polymers. These methods can greatly increase the rate of flotation for the particles that are usually difficult to float, such as ultrafine particles, coarse particles, middlings, and the particles that do not readily float in the water containing large amounts of ions derived from the particles. In addition, new collectors for the flotation of phosphate minerals are disclosed.

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&#xb0;. 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&#xb0;. 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.

Methods of enhancing fine particle dewatering

Method of increasing flotation rate

A method 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. A lipid of vegetable or animal origin is then added to the slurry in solutions of light hydrocarbon oils and short-chain alcohols, so that the hydrophobic lipid molecules adsorb on the moderately hydrophobic surface and, thereby, greatly enhance its hydrophobicity. By virtue of the enhanced hydrophobicty, the water molecules adhering to the surface are destabilized and more readily removed during the process of mechanical dewatering. The moisture reduction can be further improved using appropriate electrolytes in conjunction with the lipids, spraying surface tension lowering reagents onto the filter cake, subjecting the cake to a suitable vibratory means, and using combinations thereof.

Methods of using natural products as dewatering aids for fine particles

Growing community of inventors

Blacksburg, VA, United States of America

Roe-Hoan Yoon