Improved methods for the removal of heavy metals, in particular cadmium, from an aqueous phosphoric acid containing composition, wherein an ionic polymeric flocculating agent is added to a phosphoric acid containing composition subsequent to the addition of an organothiophosphorous heavy metal precipitating agent to said composition, particularly under gentle mixing conditions, such as between 100 and 300 rpm. The flocculating agent promotes the formation of agglomerates of the heavy metal containing precipitate, thus facilitating their removal from the composition. More in particular, the phosphoric acid containing composition is obtained by the acid digestion of phosphate rock, preferably by nitric acid, sulfuric acid, or a combination thereof.

A method for collecting silver ions and phosphoric acid in a waste fluid includes collecting silver chloride from the waste fluid, collecting silver chloride including providing a chloride compound to the waste fluid; and collecting phosphoric acid, collecting phosphoric acid including distilling the waste fluid from which the silver chloride has been collected.

A method for collecting silver ions and phosphoric acid in a waste fluid includes collecting silver chloride from the waste fluid, collecting silver chloride including providing a chloride compound to the waste fluid; and collecting phosphoric acid, collecting phosphoric acid including distilling the waste fluid from which the silver chloride has been collected.

This invention relates generally to new findings to improve a method of thermal energy storage or heat pump, i.e. increase the thermal energy from an external heat source, using a reversible condensation reaction with an inorganic oxoacid compound. It accordingly provides components to be used in said improved process as well as the use thereof in the aforementioned method, including the use in the manufacture of products of the condensation products or in the manufacture of the hydrolysis products.

This invention relates generally to new findings to improve a method of thermal energy storage or heat pump, i.e. increase the thermal energy from an external heat source, using a reversible condensation reaction with an inorganic oxoacid compound. It accordingly provides components to be used in said improved process as well as the use thereof in the aforementioned method, including the use in the manufacture of products of the condensation products or in the manufacture of the hydrolysis products.

A process may involve digesting raw phosphate with concentrated sulfuric acid and converting the raw phosphate to calcium sulfate in the form of dihydrate and/or hemihydrate, and phosphoric acid, separating off calcium sulfate as solid from a liquid phase of a suspension that is obtained, treating the calcium sulfate that is separated off or from a stockpile with an acid to give a suspension with purified calcium sulfate and P.sub.2O.sub.5-containing acid solution, separating off the purified calcium sulfate as solid from a liquid phase of a suspension obtained, using the P.sub.2O.sub.5-containing liquid phase as a portion of the sulfuric acid required for digesting the raw phosphate or as feedstock for treating phosphogypsum from the stockpile to give a suspension of purified calcium sulfate and P.sub.2O.sub.5-containing acid solution, which is thereafter processed.

A process may involve digesting raw phosphate with concentrated sulfuric acid and converting the raw phosphate to calcium sulfate in the form of dihydrate and/or hemihydrate, and phosphoric acid, separating off calcium sulfate as solid from a liquid phase of a suspension that is obtained, treating the calcium sulfate that is separated off or from a stockpile with an acid to give a suspension with purified calcium sulfate and P.sub.2O.sub.5-containing acid solution, separating off the purified calcium sulfate as solid from a liquid phase of a suspension obtained, using the P.sub.2O.sub.5-containing liquid phase as a portion of the sulfuric acid required for digesting the raw phosphate or as feedstock for treating phosphogypsum from the stockpile to give a suspension of purified calcium sulfate and P.sub.2O.sub.5-containing acid solution, which is thereafter processed.

Disclosed is a method for preparing iron phosphate and by-product fertilizer using ammonium phosphate. The granulation device for by-product fertilizer production comprises a housing having accommodation space which is divided from top to bottom into a granulation chamber, a material-screening chamber and a temporary material-storing chamber; a blowing component provided between the granulation chamber and the material-screening chamber; and a vibrating screen which is able to vertically reciprocated provided between the material-screening chamber and the temporary material-storing chamber which is connected to a discharge pipe, wherein the upper end of the housing is provided with a detachable cover having multiple spraying devices for spraying the molten material into the housing and connected to an exhaust pipe. The blowing component comprises multiple staggered and interconnected distribution pipes the upper end of which is connected to multiple blasting pipes and a side of which is connected to an intake pipe.

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.

Provided is a method of recovering phosphoric acid from a fermentation broth or a waste liquid thereof and reusing the recovered phosphoric acid in fermentation.