Methods of treating tailings
AssigneeKemira Oyj
InventorsMiguel Pelaez, Thomas Fenderson
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Abstract
The present embodiments generally relate to methods for the treatment of tailings, e.g., oil sands tailings, including methods comprising the use of one or more flocculants, one or more coagulants and one or more oxidants to treat said tailings and/or to improve the performance of said one or more flocculants.
Claims24
A method of treating tailings stream comprising adding to the tailings stream (i) at least one anionic polyacrylamide flocculant, and further adding to the anionic polyacrylamide flocculant containing tailings stream (ii) at least one oxidant, which is in the form of a solid and/or slurry, and further wherein the at least one oxidant dissolves over a prolonged time period thereby providing for prolonged oxidation and (iii) at least one iron containing coagulant, wherein the added amount(s) of the at least one oxidant which is in the form of a solid and/or a slurry and the at least one coagulant when added to the anionic polyacrylamide flocculant containing tailings stream results in a greater decrease in the chemical oxygen demand (COD) and the turbidity of the treated tailings stream compared to the decrease in COD and turbidity obtained upon the addition of the same at least one oxidant which is in the form of a solid and/or slurry, when added in the same amount to the anionic polyacrylamide flocculant containing tailing stream in the absence of the at least one coagulant.
A method of treating tailings stream comprising adding to the tailings stream:
- (a) at least one anionic polyacrylamide flocculant, and further adding to the anionic polyacrylamide flocculant containing tailings stream,
- (b) at least one solid oxidant which is in the form of a solid and/or slurry, such that when added to the tailings it dissolves over a prolonged duration thereby providing for the prolonged release of peroxides, and
- (c) at least one iron containing coagulant,
- wherein:
- (i) the at least one coagulant comprises ferrous chloride,
- (ii) the at least one oxidant which is in the form of a solid and/or slurry,
- comprises calcium peroxide, and
- (iii) the added amount(s) of the ferrous chloride and the calcium peroxide, when added to the anionic polyacrylamide flocculant containing tailings stream results in the prolonged release of peroxides as the calcium peroxide dissolves over a prolonged time period thereby providing for the prolonged oxidation of the treated tailings stream, and further wherein the combination of (i) and (ii) results in a greater decrease in the chemical oxygen demand (COD) and the turbidity of the treated tailings stream compared to the decrease in COD and turbidity obtained upon the addition of the calcium peroxide in the same amount to the anionic polyacrylamide flocculant containing tailing stream in the absence of the at least one coagulant.
Dependencies are inferred from the claim text.