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US 9,963,759 B2Granted
Method for recovering ash from waste incineration
AssigneeEcophos S.A.
InventorMohamed Takhim
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Abstract
Methods treat ash from waste incineration, wherein the methods at least comprise: a) the digestion of the ash by a leaching liquor containing phosphate ions in solution such as to form a first solid phase comprising impurities and a first liquid phase comprising phosphate ions; and b) the separation of said first liquid phase comprising phosphate ions from said first solid phase. Step a) is carried out for a duration of less than one hour or at a temperature of more than 40° C.
Claims18
A treatment method for ash from waste incineration, comprising:
- a) digesting ash by a leaching liquor containing phosphate ions in solution, which forms a first solid phase containing the impurities and a first liquid phase containing the phosphate ions, and
- b) separating the said first liquid phase containing phosphate ions and the said first solid phase,
- wherein the ash is digested in a) by the leaching liquor containing phosphate ions in solution for a duration of between 5 minutes and 45 minutes and at a temperature of more than 40° C., and wherein the ash before a) has a phosphorous content, expressed in weigtht percentage of phosphates in the form of PO4, between 7% and 67.5%.
A method for treating ash from waste incineration that consists of:
- a) digesting ash, originating from the incineration of sewage sludge, bones or manure, having a phosphorous content, expressed in percentage by weight of PO4 in the ash, of at least 1%, by a first phosphoric acid solution, in order to form a first solid phase containing the impurities and a first liquid phase containing phosphate ions, with the weight ratio between the said first phosphoric acid solution and the ash being greater or equal to 2, wherein the said first phosphoric acid solution has a weight percentage in phosphate ions between 7% and 55% by weight of phosphate ions based on the total weight of the leaching liquor, wherein the digesting is executed for a duration between 5 minutes and 45 minutes, at a temperature between 50° C. and 65° C.;
- b) separating said first liquid phase containing the phosphate ions and the said first solid phase,
- b′) optionally, treating the first liquid phase containing phosphate ions using activated carbon,
- c) purifying said first liquid phase containing phosphate ions, by the application of an ion exchange or by a liquid-liquid extraction, to obtain a second phosphoric acid solution,
- c′) optionally, treating said phosphoric acid solution using activated carbon.
2 more elements
Dependencies are inferred from the claim text.