石油焦作还原剂对低品位红土镍矿与赤泥共还原制备镍铁的影响

石油焦作为工业固体废物，其堆积和储存对生态环境产生巨大的影响。本文对石油焦在低品位红土镍矿与赤泥共还原过程中用作还原剂的可行性及其机理进行了研究。通过研究石油焦用量、焙烧温度和焙烧时间等对红土镍矿与赤泥共还原过程的影响，确定最佳的工艺条件为石油焦用量20wt%、焙烧温度1250°C、焙烧时间60 min。在此条件下，可以获得镍品位1.96wt%、铁品位85.76wt%、镍回收率97.83wt%、铁回收率96.81wt%的镍铁产品。扫描电镜和能谱(SEM–EDS)分析结果表明，红土镍矿与赤泥共还原过程中镍和铁主要以镍铁颗粒的形式存在，镍铁颗粒分布均匀且纯度很高，粒径约30 μm。结果表明，石油焦作为还原剂用于红土镍矿和赤泥共还原是可行的，与无烟煤作还原剂相比，石油焦具有成本低的优点。研究结果不仅为石油焦的利用提供了一个新途径，同时也为缺煤地区红土镍矿与赤泥共还原工艺的利用提供了一种解决方案。

Petroleum coke as reductant in co-reduction of low-grade laterite ore and red mud to prepare ferronickel: Reductant and reduction effects

Petroleum coke is industrial solid wastes and its disposal and storage has been a great challenge to the environment. In this study, petroleum coke was utilized as a novel co-reduction reductant of low-grade laterite ore and red mud. A ferronickel product of 1.98wt% nickel and 87.98wt% iron was obtained with 20wt% petroleum coke, when the roasting temperature and time was 1250°C and 60 min, respectively. The corresponding recoveries of nickel and total iron were 99.54wt% and 95.59wt%, respectively. Scanning electron microscopy–energy dispersive spectrometry (SEM–EDS) analysis showed metallic nickel and iron mainly existed in the form of ferronickel particles which distributed uniformly at a size of approximately 30 μm with high purity. This study demonstrated that petroleum coke is a promising reductant in the co-reduction of laterite ore and red mud. Compared to other alternatives, petroleum coke is advantageous with reduced production cost and high applicability in anthracite-deficient areas.