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WWW.PRAYON.COM

FEATURESOF

PRAYONTECHNOLOGIES

DESIGN

In order to improve the overall performance of phosphoric acid plants, PRAYON TECHNOLOGIES

continually updates the design of the equipment used in the process to improve recovery, energy

efficiency and the operability of the plant.

REACTOR DESIGN

The PRAYON TECHNOLOGIES reactor

design is unique. It is proven to be highly

reliable. Its multi-compartments design

allows flexibility and easy control of the

sulphate in the attack section, which re-

duces P

2

O

5

losses in the calcium sulphate

and increases the profitability of the unit.

SULPHATE GRADIENT OF THE

SLURRY IN THE ATTACK TANK

Two types of insoluble losses are pro-

duced during the production of phos-

phoric acid. These are the cocrystallised

and the unreacted losses. The level of

each loss in the gypsum is a function of

several parameters including the sulphate

concentration in the reactor. When the

sulphate concentration of the reaction

slurry is high, cocrystallised losses are

low. When the concentration is low, unre-

acted losses are low. In the reaction tank,

rock is added in the first compartment.

As sulphuric acid is not added to this

compartment, the sulphate concentra-

tion is low. This results in the dissolution

of the rock in a media where unreacted

losses are low. In the compartments 2

and 3, sulphate concentration is gradually

increased to reduce the cocrystallised

losses. The design of the reaction tank

thus minimises the insoluble losses. The

level of sulphate gradient from one zone

to the other can be adjusted depending

upon the process parameters and the

origin of the phosphate rock.

After leaving the attack section, the slurry

flows into the digestion section, where it

will desaturate before being fed to the

filter. Consequently, the gypsum crys-

tals will be large and the slurry will be

desaturated. This feature significantly

reduces filter scaling, which enables the

plant to be run for longer periods bet-

ween washes. The increase in stability

improves the overall recovery of the unit

and the onstream time and thus increases

the return on investment.

Optional Sulphate

High Sulphate

Low Sulphate

Digestion

R