Process for recovering phosphorus from ashes coming from combustion plants that are fed with renewables and/or waste materials as solid fuel, comprising a phase of mixing said ashes coming from combustion plants that are fed with renewables and/or waste materials as solid fuel with a sulfuric acid solution, in order to extract the phosphorus therein contained; a system for carrying out said process is also described.

It is introduced that a device of manufacturing lithium sulfate comprising: a reaction body in which a reaction of lithium phosphate and sulfuric acid is performed, the reaction body being divided into an upper space and a lower space; a pressurizer for applying pressure to the inside of the reaction body; a stirrer disposed in the upper space for stirring the lithium phosphate and sulfuric acid to produce a mixture containing lithium sulfate and phosphoric acid; and a filter disposed inside the reaction body and separating the filtrate containing the phosphoric acid into the lower space by filtering the mixture.

The invention relates to a method for the industrial preparation of phosphoric acid from an aqueous suspension comprising water and particles of at least one phosphate material dispersed in the presence of at least one additive of the anionic polymer type. Phosphoric acid is obtained by treating this suspension with at least one strong acid. The polymer is obtained by polymerization reaction of at least one acid selected from acrylic acid, methacrylic acid and salts thereof.

The invention relates to the use of this anionic polymer as well as the method for improving the rheology of the suspension and the hydrodynamics of the reaction medium in which the reactions for the manufacture of phosphoric acid take place.

The invention relates to a method for the industrial preparation of phosphoric acid from an aqueous suspension comprising water and particles of at least one phosphate material dispersed in the presence of at least one additive of the anionic polymer type. Phosphoric acid is obtained by treating this suspension with at least one strong acid. The polymer is obtained by polymerization reaction of at least one acid selected from acrylic acid, methacrylic acid and salts thereof.

The invention relates to the use of this anionic polymer as well as the method for improving the rheology of the suspension and the hydrodynamics of the reaction medium in which the reactions for the manufacture of phosphoric acid take place.

Disclosed herein are compositions and methods of mitigating scale in phosphoric acid and ammonium phosphate plants. Scale-mitigating compositions of the invention can be added to phosphoric acid before or during the concentration in the evaporator cycle of a phosphoric acid plant. The compositions retard the formation of scale on surfaces in contact with the phosphoric acid, and thus time between cleaning is extended and plant productivity increased. Further, the scale that forms is softer and more easily cleaned from surfaces, reducing non-operation time of the plant and/or evaporator. Methods of mitigating scale formation in phosphoric acid production and phosphoric acid handling plants are disclosed. In the methods, scales accumulate more slowly and are softer, more tractable, and more easily cleaned from surfaces to which they adhere.

Disclosed herein are compositions and methods of mitigating scale in phosphoric acid and ammonium phosphate plants. Scale-mitigating compositions of the invention can be added to phosphoric acid before or during the concentration in the evaporator cycle of a phosphoric acid plant. The compositions retard the formation of scale on surfaces in contact with the phosphoric acid, and thus time between cleaning is extended and plant productivity increased. Further, the scale that forms is softer and more easily cleaned from surfaces, reducing non-operation time of the plant and/or evaporator. Methods of mitigating scale formation in phosphoric acid production and phosphoric acid handling plants are disclosed. In the methods, scales accumulate more slowly and are softer, more tractable, and more easily cleaned from surfaces to which they adhere.

The invention relates to a method for preparing an aqueous suspension of at least one phosphate material, comprising, dispersing, in water, particles of phosphate material in the presence of at least one additive of the anionic polymer of acrylic acid or of methacrylic acid type. The suspension according to the invention has a viscosity of less than 1500 mPa.Math.s. The invention also relates to the conditioning of the phosphate material associated with the anionic polymer, for its subsequent treatment with at least one strong acid, for the industrial preparation of phosphoric acid.

The invention relates to a method for preparing an aqueous suspension of at least one phosphate material, comprising, dispersing, in water, particles of phosphate material in the presence of at least one additive of the anionic polymer of acrylic acid or of methacrylic acid type. The suspension according to the invention has a viscosity of less than 1500 mPa.Math.s. The invention also relates to the conditioning of the phosphate material associated with the anionic polymer, for its subsequent treatment with at least one strong acid, for the industrial preparation of phosphoric acid.

A method for reducing formation of scale in phosphoric acid production is provided herein. Phosphate-containing ore is combined with an acid to form an acidic slurry and the acidic slurry is processed to form an acidic stream. The method includes providing a scale inhibitor including an inorganic phosphate. The method further includes combining the scale inhibitor and at least one of the phosphate-containing ore, the acidic slurry, and the acidic stream, to reduce the formation of scale. A system for phosphoric acid production exhibiting a reduced formation of scale is also provided herein. The system includes a substrate having a surface in contact with at least one of the phosphate-containing ore, the acidic slurry formed from the phosphate-containing ore and the acid, and the acidic stream formed from the acidic slurry. The system including the scale inhibitor exhibits a reduced formation of scale on the surface.

A method for reducing formation of scale in phosphoric acid production is provided herein. Phosphate-containing ore is combined with an acid to form an acidic slurry and the acidic slurry is processed to form an acidic stream. The method includes providing a scale inhibitor including an inorganic phosphate. The method further includes combining the scale inhibitor and at least one of the phosphate-containing ore, the acidic slurry, and the acidic stream, to reduce the formation of scale. A system for phosphoric acid production exhibiting a reduced formation of scale is also provided herein. The system includes a substrate having a surface in contact with at least one of the phosphate-containing ore, the acidic slurry formed from the phosphate-containing ore and the acid, and the acidic stream formed from the acidic slurry. The system including the scale inhibitor exhibits a reduced formation of scale on the surface.