Processes for inhibiting scale produced during wet process phosphoric acid production by adding a scale-inhibiting amount of a reagent having a primary amine-containing polymer to at least one stage of a wet process phosphoric acid production process are provided herein, wherein said primary amine-containing polymer includes one or more organic moieties that reduce the polymer's solubility in an aqueous environment as compared to its native form, thereby reducing or preventing scale in the wet process phosphoric acid production process.

Processes for inhibiting scale produced during wet process phosphoric acid production by adding a scale-inhibiting amount of a reagent having a primary amine-containing polymer to at least one stage of a wet process phosphoric acid production process are provided herein, wherein said primary amine-containing polymer includes one or more organic moieties that reduce the polymer's solubility in an aqueous environment as compared to its native form, thereby reducing or preventing scale in the wet process phosphoric acid production process.

A method for mass production of phosphoric acid with a rotary kiln, comprising the following steps: pretreating raw materials a carbonaceous reductant; preparing the pre-treated carbonaceous reductant powder; then evenly mixing the carbonaceous reductant powder and the silica powder to obtain a cladding material; mixing the cores and the cladding material for cladding treatment, drying and solidifying same to obtain composite pellets; sending the composite pellets into a rotary kiln for a reduction reaction; sending the high-temperature slag balls exiting the rotary kiln to a cooling device for comprehensive utilization; introducing the fume containing P.sub.2O.sub.5 and fluorine exiting the kiln into a hydration tower for absorbing phosphorus by hydration, then passing same through a phosphoric acid mist capturing tower and a mist removing and separating tower successively, and the fluorine-containing fume discharged from the mist removing and separating tower entering a subsequent fluorine recovery procedure.

A method for mass production of phosphoric acid with a rotary kiln, comprising the following steps: pretreating raw materials a carbonaceous reductant; preparing the pre-treated carbonaceous reductant powder; then evenly mixing the carbonaceous reductant powder and the silica powder to obtain a cladding material; mixing the cores and the cladding material for cladding treatment, drying and solidifying same to obtain composite pellets; sending the composite pellets into a rotary kiln for a reduction reaction; sending the high-temperature slag balls exiting the rotary kiln to a cooling device for comprehensive utilization; introducing the fume containing P.sub.2O.sub.5 and fluorine exiting the kiln into a hydration tower for absorbing phosphorus by hydration, then passing same through a phosphoric acid mist capturing tower and a mist removing and separating tower successively, and the fluorine-containing fume discharged from the mist removing and separating tower entering a subsequent fluorine recovery procedure.

A system for extracting uranium from wet-process phosphoric acid (WPA), includes an ion exchange resin or solvent extractor for separating uranium from WPA to produce a loaded uranium solution stream and a uranium depleted WPA stream. An ion exchange resin is positioned to receive the loaded uranium solution stream and bind uranium species thereto. An anion solution stream is positioned to feed a solution comprising anions onto the ion exchange resin to form a loaded uranium eluant stream. The loaded uranium eluant stream may then be treated to provide a uranium containing product.

A system for extracting uranium from wet-process phosphoric acid (WPA), includes an ion exchange resin or solvent extractor for separating uranium from WPA to produce a loaded uranium solution stream and a uranium depleted WPA stream. An ion exchange resin is positioned to receive the loaded uranium solution stream and bind uranium species thereto. An anion solution stream is positioned to feed a solution comprising anions onto the ion exchange resin to form a loaded uranium eluant stream. The loaded uranium eluant stream may then be treated to provide a uranium containing product.

Processes for inhibiting scale produced during wet process phosphoric acid production by adding a scale-inhibiting amount of a reagent having a primary amine-containing polymer, or salt thereof, to one or more stages of a wet process phosphoric acid production stream are provided herein, wherein the primary amine-containing polymer includes an A mer according to Formula (I): ##STR00001## where R is H, C.sub.1-C.sub.6 alkyl, C.sub.2-C.sub.6 alkenyl, halide, or carboxyl; R.sup.1 is H, C.sub.1-C.sub.6 alkyl, or C.sub.2-C.sub.6 alkenyl; R.sup.2 is H or an A mer according to Formula (I) as herein defined; R.sup.3 is chosen from a direct bond or a C.sub.1-C.sub.12 alkyl, C.sub.2-C.sub.12 alkenyl, or a C.sub.6-C.sub.12 aryl group; and n is an integer chosen to provide a weight average molecular weight of the primary amine-containing polymer of at least 300 Daltons, and
wherein the percentage of primary amines in the polymer is from 30 mole % to 100 mole % based on the total percentage of mer units in the polymer.

Processes for inhibiting scale produced during wet process phosphoric acid production by adding a scale-inhibiting amount of a reagent having a primary amine-containing polymer, or salt thereof, to one or more stages of a wet process phosphoric acid production stream are provided herein, wherein the primary amine-containing polymer includes an A mer according to Formula (I): ##STR00001## where R is H, C.sub.1-C.sub.6 alkyl, C.sub.2-C.sub.6 alkenyl, halide, or carboxyl; R.sup.1 is H, C.sub.1-C.sub.6 alkyl, or C.sub.2-C.sub.6 alkenyl; R.sup.2 is H or an A mer according to Formula (I) as herein defined; R.sup.3 is chosen from a direct bond or a C.sub.1-C.sub.12 alkyl, C.sub.2-C.sub.12 alkenyl, or a C.sub.6-C.sub.12 aryl group; and n is an integer chosen to provide a weight average molecular weight of the primary amine-containing polymer of at least 300 Daltons, and
wherein the percentage of primary amines in the polymer is from 30 mole % to 100 mole % based on the total percentage of mer units in the polymer.

Methods for removing heavy metals from a phosphoric acid solution produced in a wet process for manufacturing phosphoric acid, comprising treating the wet-process phosphoric acid solution with a small amount of a solid adsorbing material and a complex reagent to form a heavy metal complex-contaminated solid adsorbing material, and removing the contaminated solid adsorbing material to yield a treated phosphoric acid solution having a low heavy metal content.

The present invention refers to an improved process for recovering phosphoric acid from sewage sludge ash, said process comprising a leaching step; a transforming step for converting phosphate metallic salts into phosphoric acid; a solvent extraction of the phosphoric acid from the leached solution with an organic solvent; a washing step for removing sulfuric acid; and stripping of phosphoric acid to obtain an aqueous solution containing phosphoric acid.