Abstract: With the capacity of 30 000 t/a thermal process phosphoric acid plant as the design benchmark，technological process，technical features，and main operating conditions of a thermal process phosphoric acid production plant with heat energy utilization were introduced.Material balance，heat balance，and the main equipment selection were calculated.Process design of the equipment was successful base on the established plant reaching standard and output，and on stable operation and reliability service of built devices.The effect of energy saving，water saving， and emission reduction with the patented technology was summarized，and the significance of the technology was also pointed out to China′s current energy conservation and emissions reduction.

Key words: thermal process phosphoric acid；high efficient utilization of heat energy；reaction heat；steam, process design