Minerals phase transformation by hydrogen reduction ... ScienceDirect
The fineness of the limonite sample used in this study was 100 wt% minus mm. The chemical composition is presented in Table 1, indicating that the total iron content was %.The main impurities were SiO 2 and Al 2 O 3, with contents of % and %, loss on ignition (LOI) was %, revealing that the sample contained much constitutional water.