通过采用空气萃取法工艺实现磷矿伴生超低品位碘资源的回收，采用H₂O₂作氧化剂将磷酸车间稀磷酸及氟硅酸中的碘离子催化氧化成碘分子，通过空气萃取吹出法将混合酸中的碘分子以气相吹入SO₂循环吸收液中，通过SO₂还原剂将碘分子还原为碘离子，当吸收液中碘离子浓度达到30~70 g/L后，以CaCO₃和铝盐絮凝剂净化碘吸收液，之后将H₂O₂氧化剂通入吸收液中，碘离子再次被氧化为碘分子，经液固分离即得到碘产品。通过控制成本在15万元/t时，碘总回收率约为70%。通过在某磷酸车间建造2×50 t/a碘回收装置，成功实现含碘稀磷酸和含碘氟硅酸共用1套碘回收装置。该碘回收装置新增产值约2 500万元/a，实现利润超过1 000万元/a。

The ultra-low grade iodine resources associated in phosphate rock are recovered by air extraction process.Under the existence of catalyst,using H₂O₂ as oxidant,iodine ions in dilute phosphoric acid and fluorosilicate acid from the phosphoric acid workshop are oxidized into iodine molecules.Then the iodine molecules in the mixed acids are blown into SO₂ circling absorption solution by air extraction blowing process and then are reduced into iodine ions by SO₂ reduction agent.When the concentration of iodine ions in the absorption solution reaches 30-70 g·L^-1,the absorption solution is purified with CaCO₃ and aluminum salt flocculant.After that,H₂O₂ is led into the absorption solution to oxidize iodine ions into iodine molecules once again.Finally,the iodine product is obtained through separating liquid and solid.If the recovery cost is controlled to be less than RMB150 000 per ton iodine,then the total recovery rate of iodine is about 70%.Two 50 t/a iodine recovery lines are constructed at a phosphoric acid workshop,the recovery of iodine resources in both dilute phosphoric acid and fluorosilicate acid can be realized in a same recovering line.These two iodine recovery lines can annually increase production value by about RMB25 million,and achieve a profit of more than RMB10 million per year.

彭宝林(1986-),男,工程师,从事磷化工生产技术研究工作