微波-化学溶液联合作用下矿石的劣化机理研究

为了提高微波辅助磨矿的适用性，以红透山铜矿和思山岭铁矿为研究对象，分别采用微波、盐酸溶液、草酸溶液及其组合的方式对矿石进行预处理。对比了7种预处理方式下矿石的升温特征、表面形态、磨矿效果，并通过介电常数、波速、微观照片揭示矿石的劣化机理。试验结果表明：铜矿和铁矿浸酸后介电常数减小，导致微波作用下升温速率降低，温度分布更加均匀。铜矿经过盐酸-微波处理，表面有灼烧痕迹，而经过微波-盐酸处理，表面产生裂纹，矿物边界明显。铁矿微波辐射后表面颜色变黄，酸处理后颜色还原。7种预处理方式中，微波-盐酸联合作用磨矿效果最佳，铜矿和铁矿的质量折减百分比分别为15%和14.5%，相比于未处理矿石，磨矿产物质量分别提高58%和78%。微观照片和波速测试结果表明微波照射后矿石产生明显的裂纹，再经盐酸浸泡后，裂纹宽度进一步加大，并在裂纹中产生沉淀物。研究表明，微波与盐酸联合作用可以进一步弱化矿石，提高磨矿效果。

Study on the deterioration mechanism of ores with the combination of microwave and chemistry solution

In order to improve the applicability of microwave-assisted grinding, Hongtoushan copper ore and Sishanling iron ore were selected. The ores were pretreated separately by microwave, hydrochloric acid solution, oxalic acid solution and their combination. The heating characteristics, surface morphology and grinding product mass of ores were compared in seven pretreatment methods, and the dielectric constant, wave velocity and microscopic photos were used to reveal the deterioration mechanism of ores. The results show that the permitivity of the ores soaked in hydrochloric acid reduces, resulting in the decrease of heating rate and the more even temperature distribution with microwave irradiation. After hydrochloric acid and microwave treatment, there are burning traces on the surface of the copper ore, however, after microwave and hydrochloric acid treatment, there are cracks and obvious mineral boundaries on the surface of copper ore. The surface color of iron ore turns yellow after microwave radiation and is restored after acid treatment. Among the seven pretreatment methods, the combination of microwave and hydrochloric acid gets the best grinding effect.The mass reduction percentage of copper and iron ores are 15% and 14.5% respectively. Compared with untreated ores, the mass of grinding product is increased by 58% and 78% respectively. The micro photos and wave velocity results show that the ores generate obvious cracks after microwave irradiation. After ores soaked in hydrochloric acid, the crack width increases furtherly and the deposits appear in crack. The research indicates that combination of microwave and hydrochloric acid can weaken the ore furtherly and improve the grinding effect.