白云石质磷尾矿悬浮态煅烧实验研究

Research on suspension calcination of dolomitic phosphorus tailings

白云石质磷尾矿的主要矿物成分是钙质白云石、氟磷灰石和石英,磷尾矿煅烧产品可以用来提取工业氧化镁、活性石灰和磷精矿。采用高固气比悬浮态煅烧技术对瓮福磷尾矿进行煅烧实验。该系统易于控制,炉内温度均衡稳定。物料在系统内停留时间仅为20～30 s时,煅烧产品的表观分解率达到92.9%,白云石中的碳酸镁基本完全分解。产品颗粒疏松多孔,晶粒细小,氧化钙和氧化镁的质量分数分别为43.31%和29.20%,产品水化活性高;五氧化二磷质量分数由6.36%升至10.00%,有利于进一步提取磷精矿。

The essential mineral compositions of dolomitic phosphorus tailings are calcareous dolomite,fluorapatite,and quartz, and its calcining product can be used to extract industrial magnesia, active lime, and phosphate concentrate.The phos- phorus tailings from Wengfu were calcined with the high solid-gas ratio suspension calcining technology.The system was easy to control, and the furnace temperature was steady.The residence time of powder in the furnace was only at 20-30 s, the ap- parent decomposition rate of calcined products reached 92.9% ,and MgCO3 in dolomite was almost completely decomposed. The as-prepared product particles were all small grains,loose and porous, and exhibited a higher hydration activity.The mass fractions of CaO and MgO were 43.31% and 29.20% ,respectively.Mass fraction of P205 increased to 10.00% from 6.36%, which was favorable to further extract phosphate concentrate.