铁矿粉湿容量的概念及其在制粒过程中的应用

The conception of moisture capacity for iron ore and its application to granulation

适宜的配水量对改善铁矿粉的制粒效果起重要作用。为建立一种简单易行、准确合理的方法,提出了铁矿粉湿容量的概念,即单位质量的矿物在自然堆积的状态下所能保持的最大含水量,并开发出相关测试设备。利用该方法对来自某实际生产过程中的5组混合料进行了测试,得到了每组混合料的湿容量。在实验室规模的设备上进行了5组混合料在不同配水量条件下的制粒实验,并对其透气性进行了检测,得到了每组原料的最佳配水量。对比每组混合料的湿容量和最佳配水量发现:两个参数之间具有很强的正相关性,湿容量大的混合料需要配加更多的水后料层才能达到最佳的制粒效果。还对料层的透气性和粒度分布关系做了讨论。实验发现随着加水量的增多,颗粒制粒后的粒度逐渐增大,料层的透气性先增大后减小。

The optimal water content added into the iron ore mixtures is of vital importance for improving granulation.A novel conception about moisture capacity of the iron ore,which means the maximum water content holding in the iron ore particles of unit mass,is proposed to develop a simple and accurate method.The related equipment and measuring procedure are also given.Five mixtures are selected for moisture capacity measuring,and the granulation experiments with the laboratory scale equipment are also carried out for the five mixtures with various water levels,and the permeability of the granules are also measured to get the optimal water content for each mixture.Comparing the optimal water content with the moisture capacity finds that the two parameters have a good positive relation,meaning that more water is necessary for the mixture with high moisture capacity to get a good permeability index.The relationship between the permeability index and particle size distribution is also discussed.It is found that the size of the granules increases with the increase of water content and the permeability of the burden first increases and then decreases with the increase of water content.