A large number of studies have shown that oolitic hematite is an iron ore that is extremely difficult to utilize because of its fine disseminated particle size, high harmful impurity content and oolitic structure. To recover iron from oolitic hematite, we developed a novel multistage dynamic magnetizing roasting technology. Compared with traditional magnetizing roasting technologies, this novel technology has the following advantages: firstly, the oolitic hematite is dynamically reduced in a multi-stage roasting furnace, which shortens the reduction time and avoids ringing and over-reduction; secondly, the novel dynamic magnetizing roasting technology has strong raw material adaptability, and the size range of raw materials can be as wide as 0–15 mm; thirdly, the roasting furnace adopts a preheating-heating process, and the low-calorific value blast furnace gas can be used as the fuel and reductant, which greatly reduces the cost. The actual industrial production data showed that the energy consumption in the roasting process can be less than 35 kg of standard coal per ton of raw ore. The iron grade of the concentrate and iron recovery reached 65% and 90%, respectively.

大量研究表明，鲕粒型赤铁矿是一种极难利用的铁矿石，其浸染性粒度细，有害杂质含量高，具有鲕状结构。为了从鲕粒赤铁矿中回收铁，我们开发了一种新颖的多级动态磁化焙烧技术。与传统磁化焙烧技术相比，该新技术具有以下优点：一是鲕粒赤铁矿在多级焙烧炉中动态还原，缩短了还原时间，避免了环化和过还原；二是新颖的动态磁化焙烧技术，原料适应性强，原料粒度范围可宽至0-15mm；三、焙烧炉采用预热-加热工艺，低热值高炉煤气可用作燃料和还原剂，大大降低了成本。实际工业生产数据表明，每吨原矿焙烧​​过程能耗可低于35公斤标准煤。精矿的铁品位和铁回收率分别达到65%和90%。