P2O5对转炉钢渣矿物结构的影响

依据实际转炉钢渣理化特性,以CaO-MgO-SiO2-Fe2O3四元渣系作为基础渣系,向该渣系中加入渣量1%～7%（质量分数）的P元素,使用SEM和EDS对合成渣系矿物结构进行表征与分析。结果表明：合成渣系主要由硅酸二钙、铁酸二钙及方镁石组成,其中磷元素主要以磷酸三钙的形式固溶于硅酸二钙中,在其他相中并未发现磷元素的存在;随着磷含量的增加,磷元素在硅酸二钙矿物中的含量随之增加,并可能出现独立的磷灰石相,这可为转炉钢渣在磷肥工业的应用研究提供参考。同时,由于磷加入量增多,CaO优先与PO4]4-反应,早先存在的方镁石逐渐消失而溶入基质相。基质相2CaO·Fe2O3向CaO·MgO·Fe2O3发生转变,最后形成2MgO·Fe2O3,表明高磷含量有利于改善转炉钢渣的安定性能。

Influence of P2O5 on the Mineral Structure of Converter Steel Slag

The slag system of CaO-MgO-SiO2-Fe2O3 was synthetized on the basis of composition and mineral phase of actual converter steel slag. Residue of 1%～7%（mass fraction） P element was added into the slag system.The mineral phases of the slag samples were analyzed with SEM and EDS. Results show that the mineral phrases of the slag system are 2CaO·Si O2 with little phosphorus, periclase and the matrix phase of calcium ferrite.Phosphorus mainly occurs in the 2CaO·Si O2 in the form of 2CaO·PO4, and the other mineral phases contain very little phosphorus. Increasing the percentage of phosphorus in the slag system, the percentage of phosphorus in the2 CaO·SiO2 also increases, and the CaO·P2O5 could firstly be found in the slag. Increasing continually the percentage of phosphorus, CaO has priority for reacting with PO4]4-and the periclase gradually dissolves into the matrix phase. The martrix phase 2CaO·Fe2O3 is transformed into CaO·MgO·Fe2O3,finally 2MgO3·Fe2O3 is produced,show the high phosphorus proportion of converter steel slag is conductive to improve its stability.