高磷赤铁矿制备碳化铁的产物分离试验研究

利用高磷鲕状赤铁矿制备碳化铁,产物中含磷组分是影响碳化铁质量的关键因素。为了探究分离方式和添加剂对产物中含磷组分分离的影响,在1023K下分别用无添加、添加2%V2O5和添加5%Na2SO4的高磷鲕状赤铁矿制备碳化铁,将制得的产物球磨不同时间后采用磁选或离心+磁选的方式进行产物分离,最后分析产物中含磷组分的变化。结果表明,延长球磨时间可以提高产物的脱磷率,但球磨时间过长会降低产物的铁收得率,以球磨2h为宜;无添加剂时制备所得碳化铁试样球磨时间从1h延长至2h后,脱磷率从18.17%升至18.48%,再增加离心分离操作后,会进一步提升产物的脱磷率至23.04%;添加5%Na_2SO_4和2%V_2O_5均可破坏铁矿石的鲕状结构,有利于含Fe组分与脉石的分离,但添加Na_2SO_4会降低产物的碳化铁含量,而V_2O_5的添加则可同时促进碳化铁的生成以及提高产物的脱磷率,是一种较好的添加剂。

Experimental study on separation of the products from the preparation of iron carbide from high phosphorus hematite

The phosphorus-bearing components are the key factor that affects the quality of the product during the preparation of iron carbide from high phosphorus oolitic hematite. In order to investigate the effect of the separation method and additive on the phosphorus removal, the related experiments were conducted. Iron carbide was prepared from high phosphorus oolitic hematite with 2% V₂O₅ or 5% Na₂SO₄ or without additives at 1023 K. The characterization and the chemical compositions of the products obtained by physical separation of the combination of ball-milling, magnetic separation or with the treatment of centrifugation process and magnetic separation were then analyzed. The results show that prolonging the milling time can improve the separation of products, but too long milling time will reduce iron recovery; milling product for 2 h is the optimal condition; the dephosphorization ratio increases from 18.17% to 18.48% with the increase of milling time from 1 h to 2 h; the addition of centrifugation process can further improve the dephosphorization to 23.04%. The additives of 5% Na₂SO₄ and 2% V₂O₅ lead to the destruction of the oolitic structure, and are beneficial to the separation of Fe-bearing components and other gangue elements. However, the addition of Na₂SO₄ retards the formation of iron carbide from the high phosphorus oolitic hematite. As an additive, V₂O₅ is good for the formation of iron carbide and the separation of products with relatively high degree of dephosphorization.