Acid-Insoluble Substances in Reduced Iron Powder from Ores
X-ray analysis on iron ores and reduced iron powders revealed that around 60% acidinsoluble substances were hexagonal and tetragonal quartz, another 40% substances were sillimanite, alumina-silicate, an unnamed zeolite, all contained Si and Al. SEM images displayed that the particle size of them was in the range of 3~7 μm, which may be the initial source of the cracking in the sintered body. Statistics analysis showed that the Acid-Insoluble Content (AIC) for high-grade magnetite powder was (0.130±0.010) % during the latest five months. The predicting value for reduced iron powder from ore powders should be 0.179 %. However, the testing value for reduced iron powder was (0.192±0.014) %. The limited difference of 0.013% might imply rare pollution coming from the reduction and milling processes. The most important step for control AIC should be the separation process of iron ore powders.
Duk Yong Yoon, Suk-Joong L. Kang, Kwang Yong Eun and Yong-Seog Kim
C. L. Wang and C. G. Zhang, "Acid-Insoluble Substances in Reduced Iron Powder from Ores", Materials Science Forum, Vols. 534-536, pp. 5-8, 2007