Limonite from Shiretoko Peninsula, Hokkaido, has been examined as to its mineralogical properties, suitability for pelletizing, and properties of pellets obtained therefrom.
Results are as follows:
(1) The are consists of globular grains of irregular shape, which shows identical X-ray diffraction patterns as the artificial goethite.
(2) The value of work index of the limonite is 4.80.
(3) Green pellets having the crushing strength of 2.0kg/pellet or above can be obtained only when pellet feed contains more than 60 per cent of under 325 mesh particles.
(4) The high temperature crushing strength increases remarkably at 1100°C, so that a shaft furnace or a rotary kiln can be used for the firing of the pellets.
(5) Pellets of highest mechanical strength can be obtained by firing the green pellet containing 1% bentonite and 1% lime as binder at 1300-1350°C.
(6) The crushing strength of the pellets thus obtained is >500kg/pellet, the tumbler index >95%(1mm over), the shatter strength 100%, porosity about 20% and reducibility (JIS specification) about 60%.
