The Oxy Hemihydrate Phosphoric Acid Process

Occidental has installed two new phosphoric acid plants using the OXY hemihyrate process to meet its commitment to produce over 1,000,000 STPY P205 in the White Springs, Florida, facilities.

The process was selected based on some of the following major advantages:

• High strength acid and hence lower energy requirements.

• Lower capital costs.

• Low agitation energy requirements in the reaction vessels.

• Product acid has low impurities and low solids content.

• Reduced consumption of sulphuric acid.

• Proven ability to operate on Occidental’s wet unground rock.

• Good filtration rates.

Full scale operation of the 350STPD P20< OXY hemihydrate plant was started in 1978 and on stream rates of 525STPD P2Oj have been achieved.

The 1.430STPD P2Os OXY hemihydrate plant was started up in November 1979. Operation has been smooth, monthly operating goals have been exceeded and on stream production rates of more than 1,700STPD P2Oj have been attained.

An evaluation of current operating data indicate that Occidental is capable of producing 42% P205 acid from the OXY hemihydrate plant at a manufacturing cost of $ 11.89/STPD P2Oj less than the cost of producing 42% acid from a dihydrate plant including the necessary evaporation facilities.