Production of citrate soluble phosphates by calcination of secondary phosphate sources with a sodium-sulfuric compound
AssigneesOutotec (Finland) Oy, Bundesrepublik Deutschland, Vertreten Durch Das Bundesminsiterium FüR Wirtschaft Und Energie, Dieses Vertreten Durch Den PräSidenten Der Bam, Bundesanstalt FüR Materialforschung Und -PrüFung
InventorsJan Stemann, Christian Adam, Ludwig Hermann
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Abstract
A method of calcination includes providing a raw material including whitlockite Ca9(Mg,Fe2+)[PO3(OH)|(PO4)6], and/or iron phosphate FePO4, and/or aluminum phosphate AlPO4 and/or fluorapatite Ca5(PO4)3F; providing an alkaline-sulfuric compound as an additive; and calcining a mixture of the raw material with the additive to obtain a product, including a citrate soluble phosphate compound.
Claims23
A method of calcination, comprising:
- providing a raw material comprising whitlockite Ca9(Mg,Fe2+)[PO3(OH)|(PO4)6], and/or iron phosphate FePO4, and/or aluminium phosphate AlPO4 and/or fluorapatite Ca5(PO4)3F;
- providing an alkaline-sulfuric compound as an additive;
- providing a carbonaceous reducing agent as a second additive;
- calcining a mixture of the raw material with the additives comprising reductive activation of the alkaline-sulfuric compound;
- and
- obtaining a product, wherein the product comprises a citrate soluble phosphate compound,
- wherein the carbonaceous reducing agent comprises a phosphorus containing material, selected from a sewage sludge or a biomass.
A method of calcination, comprising:
- providing a raw material comprising whitlockite Ca9(Mg,Fe2+)[PO3(OH)|(PO4)6], iron phosphate FePO4, aluminium phosphate AlPO4, or fluorapatite Ca5(PO4)3F;
- providing an alkaline-sulfuric compound as an additive;
- providing a carbonaceous reducing agent as a second additive;
- calcining a mixture of the raw material with the additives comprising reductive activation of the alkaline sulfuric compound;
- obtaining a product, wherein the product comprises a citrate soluble phosphate compound;
- and
- controlling an atmosphere with respect to an oxygen concentration during calcining or during a cooling, wherein a content of sulfur in the product substantially corresponds to the content of sulfur in the mixture,
- wherein the raw material is an ash selected from a sewage sludge ash or a biomass ash.
A method of calcination, comprising:
- providing a raw material comprising whitlockite Ca9(Mg,Fe2+)[PO3(OH)|(PO4)6], iron phosphate FePO4, aluminium phosphate AlPO4, or fluorapatite Ca5(PO4)3F;
- providing an alkaline-sulfuric compound as an additive;
- providing a carbonaceous reducing agent as a second additive;
- calcining a mixture of the raw material with the additives comprising reductive activation of the alkaline sulfuric compound;
- and
- obtaining a product, wherein the product comprises a citrate soluble phosphate compound,
- wherein the alkaline-sulfuric compound is selected from a by-product of an industrial process selected from a rayon fiber production, a pulp manufacture, ora paper manufacture,
- or the alkaline-sulfuric compound is selected from biomass, sludge, refuse derived fuel or waste incineration.
A process for obtaining a citrate soluble phosphate compound from a P-containing raw material, the raw material comprising a P-phase selected from whitlockite Ca9(Mg,Fe2+)[PO3(OH)|(PO4)6], iron phosphate FePO4, aluminium phosphate AlPO4 or fluorapatite Ca5(PO4)3F, the process comprising:
- determining in the raw material a molar ratio of Na/Si and a molar ratio of Na/P;
- determining a quantity of a sodium-sulfuric compound based on the determined molar ratio of Na/Si and Na/P;
- calcining under reducing conditions the raw material together with the determined quantity of the sodium-sulfuric compound to obtain the citrate soluble phosphate compound;
- wherein the step of determining the quantity of the sodium sulfuric compound comprises:
- detecting a sodium quantity required to obtain by calcining the raw material the citrate soluble phosphate compound CaNaPO4 by conversion of the P-phase;
- and
- calculating an amount of the sodium-sulfuric compound corresponding to the detected sodium quantity, wherein the sodium-sulfuric compound is selected from Na2S, Na2SO3, or Na2SO4.
Dependencies are inferred from the claim text.