Deinking of waste paper
Waste paper is deinked by a composition which comprises a surfactant and a hydrophobic-based deinking component.
1. A process for deinking waste paper, wherein the process comprises:
A. treating the waste paper with a composition which comprises a surfactant and a hydrophobic kaolin-based deinking component produced by a process comprising the following steps:
(1) forming a dispersed kaolin clay slurry by blunging a crude kaolin clay with water in the presence of a dispersant;
(2) mixing the dispersed kaolin clay slurry with a hydrophobizing reagent to produce a hydrophobic kaolin-based deinking component and a non-hydrophobic kaolin-based component; and
(3) separating the hydrophobic kaolin-based deinking component from the non-hydrophobic kaolin-based component, and
B. subjecting the treated waste paper to wash deinking or flotation deinking.
2. A process as defined by claim 1 wherein the surfactant is ionic, cationic, non-ionic or a blend thereof.
3. A process as defined by claim 1 wherein the deinking component contains a silicate, oxide, carbonate, nonmetallic, sulfide or a mixture thereof.
4. A process as defined by claim 1 wherein the surfactant is a non-ionic polyalkylene oxide based surfactant.
5. A process as defined by claim 1 wherein the hydrophobizing reagent is a sulfhydryl, carboxylic acid, amine, oil, sulfonate, hydroxamate, fatty acid, siloxane or a blend thereof.
6. A process for producing a hydrophobic kaolin-based deinking component, wherein the process comprises the following steps:
(1) forming a dispersed kaolin clay slurry by blunging a crude kaolin clay with water in the presence of a dispersant;
(2) mixing the dispersed kaolin clay slurry with a hydrophobizing reagent to produce a hydrophobic kaolin-based deinking component and a non-hydrophobic kaolin-based component; and
(3) separating the hydrophoblic kaolin-based deinking component from the non-hydrophobic kaolin-based component.
7. A process as defined by claim 6 wherein the hydrophobizing reagent is a sulfhydryl, carboxylic acid, amine, oil, sulfonate, hydroxamate, fatty acid, siloxane or a blend thereof.