Preparation process of carbon-containing pellets with laterite nickel ore

Laterite nickel ore as raw materials, pulverized coal as a reductant, CaO as a flux, binder and water were pressed into carbon-containing pellets by using a twin-roller ball press. The pelletizing characteristic of laterite nickel ore was studied and the effects of some factors such as the reductant, water amount and binder on the pellet strength were investigated. It is shown that laterite nickel ore has a better pelletizing property and the pellets still have a certain strength without adding any binder. Fine-grained coal reduces the pellet strength but an appropriate content of coarse-grained coal can improve it. The compressive strength of the pellets gradually increases with the water addition amount increasing and reaches the maximum when the water addition amount comes up to 18%; however, if the water addition amount continues to increase, the compressive strength shows a decreasing tendency. The falling strength of the pellets gradually increases with the increase of water addition amount. When the bentonite addition amount increases the pellet strength gradually increases and reaches the maximum at the bentonite addition amount of 2%; however, if the bentonite addition amount continues to increase, the pellet strength declines slightly. What is more, bentonite contains higher contents of SiO₂ and Al₂0₃, which can reduce the grade of useful elements in the pellets, so the addition amount of bentonite should not be too high.