Job Description:

• 1) Controls premixer and reaction vessels to produce orthophosphate liquor by reaction of phosphoric acid with soda ash: Sets timing device on weigh tank to effect prescribed feed rate of soda ash to premixer.

• 2) Starts premixer, pumps, exhaust fans, screw conveyors, and bucket elevator in required sequence.

• 3) Observes flowmeters and turns valves to regulate flow of phosphoric acid and water to premixer as specified.

• 4) Swings discharge spout over reaction vessel, and starts agitator in vessel to admit and mix product.

• 5) Turns valve to regulate flow of steam through vessel heating coils to attain reaction, observing thermometer to verify required temperature.

• 6) Lowers dipstick into tank to obtain sample for laboratory testing.

• 7) Turns valves to add measured amounts of chemicals, as indicated by laboratory reports, to regulate chemical properties of mixture to specifications.

• 8) Turns valves and starts pump to transfer finished mixture to spray drier feed tanks.