P_2O_5含量对石膏碳铵转化过程的影响

EFFECT OF P_2O_5 TO CONVERSION PROCESS OF GYPSUM TO AMMONIUM SULFATE

以纯 Ca SO4 · 2 H2 O添加水溶 P2 O5进行石膏碳酸铵溶液转化反应实验 ,探索 P2 O5含量对转化过程的影响。实验结果表明 ,石膏中水溶 P2 O5含量增加 ,SO4 2 -转化率下降 ,产物的物性变坏。 X衍射分析与扫描电镜观察发现 :石膏所含 P2 O5会改变转化过程的 Ca CO3 晶型及晶体形状 ,减缓了 Ca CO3 由球霞石型转为方解石型的速率 ,晶粒变细而不规则、粘结聚集包裹 Ca SO4 · 2 H2 O,形成产物层 ,增加传质阻力 ,降低转化率 ,使产物过滤性能变坏。因此 ,工业化过程中应将磷石膏水溶性 P2 O5控制在

The effect of P2O5 on the conversion process of gypsum to ammonium sulfate using ammonium carbonate aqueous solution was experimentally studied. It was experimentally showed that the conversion was decreased and physics properties became bad with increase in the content of water-soluble P2O5. The results obtained from XRD and SEM indicated that water-soluble P2O5 in gypsum reduced the rate of transformation from vaterite to calcite and made crystalline grains smaller and irregular. Therefore, the content of water-soluble P2O5 in the gypsum as the by product from phosphoric acid manufacture should be less 1.0%.