| 摘要 |
A stabilized wet process for prepg. phosphoric acid comprises (a) concg. unrefined dild. phosphoric acid soln. (of wet process, wt. ratio of Fe2O3: P2O5 > 0.03) in the primary evapn. zone until P2O5 concn. is 45-55%, (b) crystg. the conce. acid soln. for 8-48 hr, (c) refining by a centrifuge to have solid below 25%, and (d) concg. in the secondary evapn. zone until P2O5 concn. is 58-63% to have low post-pptn..
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