This plant initially used stage grinding – single magnetic separation - fine screening and regrinding process. Yantai Group increased cationic reverse flotation process for undersize concentrate. The final concentrate was obtained after one roughing and one cleaning. The reverse flotation froth was sent to regrinding after thickening and magnetic separation, then magnetic concentrate returned to reverse flotation for reprocessing. Finally, iron concentrate was increased from 65.43% to 68.88%.
Yantai Group increased anionic reverse flotation process of magnetic concentrate on the basis of the single magnetic separation process. Iron ore concentrate was obtained directly with a roughing, tailings were discarded with three scavenging, middlings returned to efficient thickener. Finally, iron concentrate was increased from 64.25% to 67.22%.
The qualified iron concentrate of this project was obtained with round vibrating screen - magnetic separator. Oversize middlings were sent to closed-circuit grinding system (including wet grid type ball mill and hydrocyclone) for fine grinding. And other qualified concentrates were gained by magnetic separation - fine screen - magnetic separation, then oversize material returned to thickening and magnetic separation for reprocessing. Finally, iron concentrate was increased from 67 % to 69 %, silicon dioxide was reduced from 6.5% to 4.5 %.
Strong magnetic iron ore belongs to free-milling mine, which can get high-grade iron concentrate with weak magnetic separation process. With the improving demand of iron ore concentrate, Yantai Group has speeded up the research and innovation of magnetic iron ore dressing technology and magnetic separation equipment in recent years, and achieved remarkable results.
Yantai Group increases fine screening-regrinding process in two stage grinding, stage separation, single weak-magnetic separation process, which timely separates fine minerals, reduces the overgrinding and improves the processing capacity of ball mill. The iron concentrate grade increases by about 8%.
One stage closed-circuit grinding and classifying system consists of ball mill and cyclone, which not only guarantees the classification efficiency and classification size, but also separates the qualified concentrate in advance.
Magnetic separation timely separates the qualified coarse grain concentrate and tailings. And this combined process reduces more flotation processing quantity and reagents than direct flotation and saves a lot of flotation production cost.
Strong magnetic process recycles fine grained iron ore that plays a role in desliming and tailings discarding. The reverse floatation process has simple reagent system that greatly reduces reagent into the pulp.