Brown iron ore constitutes about 13% of the global ore reserves and is widespread throughout the world. Brown iron ore is characterized by a significant content of harmful phosphorus (0.7 to 3.0%), which is typically present in the lattice of the main iron ore component in a chemically bound form. Based on the case study of the gravity-magnetic concentrate from the Lisakovsk field, OJSC “VNIIMT” has developed and lab-tested a pyro-hydrometallurgical dephosphorization technology, which can be applied while preparing the concentrate for agglomeration. As established earlier, phosphorus leaching proceeds successfully only after a high-temperature roasting of the gravity-magnetic concentrate, when the hydrated phosphorus-containing component decomposes. Free phosphorus then reacts with sulfuric acid. The main difference of the leaching process was that dephosphorization of the preliminary roasted concentrate with weak aqueous solution of sulfuric acid was performed without cooling it (hot leaching). A fixed-bed roasting was performed in a laboratory muffle furnace. After heating to a specific temperature and soaking for 60 minutes, a crucible containing the sample of the material was removed from the furnace. The roasted material was unloaded in hot condition into a previously prepared weak aqueous solution of sulfuric acid containing 5 wt.% of H2SO4 (solid-to-liquid phase ratio — 1:2). Such ratio prevents the solution from boiling during unloading of the hot concentrate. The pulp was mixed inside the ceramic crucible using an overhead stirrer. It has been established experimentally that hot leaching significantly reduces the duration of dephosphorization (by 3 times or more) compared to leaching under normal conditions. Another important advantage is the possibility of reducing the number of pieces of process equipment industry-wide, since cooling and leaching of the roasted gravity-magnetic concentrate from the Lisakovsk field can be implemented in one apparatus. In this case, reduced duration of the leaching process will enable an increase in productivity of the dephosphorization equipment by 3 times or more.

中文翻译：

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热浸法强化Lisakovsk油田褐铁矿火法湿法脱磷工艺

褐铁矿约占全球矿石储量的 13%，在世界各地广泛分布。褐铁矿石的特点是有害磷含量很高（0.7 至 3.0%），通常以化学结合形式存在于主要铁矿石成分的晶格中。基于 Lisakovsk 油田重磁精矿的案例研究，OJSC“VNIIMT”开发并实验室测试了一种火法湿法冶金脱磷技术，该技术可在制备用于附聚的精矿时应用。如前所述，只有在重力磁精矿高温焙烧后，当水合含磷组分分解时，磷浸出才能成功进行。然后游离磷与硫酸反应。浸出工艺的主要区别在于，初焙精矿用稀硫酸水溶液脱磷是在不冷却的情况下进行的（热浸）。在实验室马弗炉中进行固定床焙烧。加热至特定温度并均热 60 分钟后，将装有材料样品的坩埚从炉中取出。在热条件下将焙烧过的材料卸载到预先制备的含有 5wt.% H2SO4（固液相比 - 1:2）的硫酸弱水溶液中。该比例可防止在卸载热浓缩物期间溶液沸腾。使用高架搅拌器在陶瓷坩埚内混合纸浆。实验表明，与正常条件下的浸出相比，热浸出显着减少了脱磷的持续时间（3 倍或更多）。另一个重要优势是可以减少整个行业的加工设备数量，因为可以在一个设备中实现对来自 Lisakovsk 油田的焙烧重力磁精矿的冷却和浸出。在这种情况下，减少浸出过程的持续时间将使脱磷设备的生产率提高3倍或更多。由于来自 Lisakovsk 油田的焙烧重磁精矿的冷却和浸出可以在一台设备中实现。在这种情况下，减少浸出过程的持续时间将使脱磷设备的生产率提高3倍或更多。由于来自 Lisakovsk 油田的焙烧重磁精矿的冷却和浸出可以在一台设备中实现。在这种情况下，减少浸出过程的持续时间将使脱磷设备的生产率提高3倍或更多。