A professional who controls premixer and reaction vessels to produce orthophosphate liquor by reaction of phosphoric acid with soda ash. Respnsibilities include:

• Sets timing device on weigh tank to effect prescribed feed rate of soda ash to premixer.
• Starts premixer, pumps, exhaust fans, screw conveyors, and bucket elevator in required sequence.
• Observes flowmeters and turns valves to regulate flow of phosphoric acid and water to premixer as specified.
• Swings discharge spout over reaction vessel, and starts agitator in vessel to admit and mix product.
• Turns valve to regulate flow of steam through vessel heating coils to attain reaction, observing thermometer to verify required temperature.
• Lowers dipstick into tank to obtain sample for laboratory testing.
• Turns valves to add measured amounts of chemicals, as indicated by laboratory reports, to regulate chemical properties of mixture to specifications.
• Turns valves and starts pump to transfer finished mixture to spray drier feed tanks.