Prayon

Damien Gabriel

Bernard Heptia

Carl Szocs

Hubert Halleux

Denis Leruth

Carl Szöcs

The present invention concerns a method for purifying at least one aqueous solution of phosphoric acid continuously, comprising at least: providing, in at least one vessel, at least one solution AP derived from at least one phosphoric acid obtained by a process for wet-chemical production of phosphoric acid, said solution in said vessel being at a temperature between 65° C. and 98° C., and said solution AP comprising before said step 1: between 50% and 63% by weight of POand between 0.1% and 0.5% by weight of SO; adding barium carbonate to said vessel, said barium carbonate having a specific particle size distribution which allows for effective flow of the barium carbonate while allowing it to have good reactivity.

Method for purification of at least one aqueous solution of phosphoric acid

A method and device for producing a solution of polyphosphoric acid from a feed solution P0 by the wet method is provided. An enriched phosphoric acid solution optionally mixed with a direct feed solution is pulverised in a flame of a combustion chamber in order to form the polyphosphoric acid solution. The combustion gases from the combustion chamber are placed in contact with the feed solution in a gas-acid contactor in order to increase the temperature and the POconcentration thereof and thus to form an enriched phosphoric acid solution. A portion of the enriched phosphoric acid solution is conveyed with a flow rate of Qp into the combustion chamber in order to be pulverised in the flame. The rest of the enriched phosphoric acid solution is conveyed into a recirculation loop in order to be reinjected into the gas-acid contactor with a flow rate of Q2. The ratio of Qp/(Qp+Q2) is controlled with a predefined value.

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Engis, Belgium

Damien Gabriel