Design the manufacture of ( tones/day) Ferrous sulphate monohydrate from waste pickle liquor.
Pickling is generally associated with the removal of scale with mineral acid. Sulphuric acid is the most commonly used pickling acid. The spent pickle liquor generally contains about 15 to 20 % ferrous sulfate and about 2 to 5 % sulphuric acid. This spent liquor is first neutralized with excess iron in a neutralization tank and then filter of excess iron. The solubility of ferrous sulfate increases up to 65 degree C and then decreases where ferrous sulfate exists as monohydrate. At ordinary low temperatures, it exists as ferrous sulfate heptahydrate. An evaporative crystallizer is used to produce ferrous sulfate monohydrate which operates at 65%.After separation of crystals, the mother liquor is recycled back to neutralization tank.
Prepare a design report consisting of the following:
1. Detailed flow sheet
2. Material and energy balance