Iron Ore Processing Solution

The iron ore challenge

The flowsheet for iron ore is decided by magnetism. Magnetite is strongly magnetic and separates easily with low-intensity magnetic drums, making it the cheapest iron ore to upgrade. Hematite and limonite are only weakly magnetic, so they need high-intensity separation, gravity or reverse flotation to reach a saleable concentrate. Many deposits are a mix of the two. Xinhai begins every iron project with a bench and pilot test at its 3,000 m² mineral test center to confirm iron deportment, the liberation grind and the right separation route.

The recommended flowsheet

For magnetite, the route is crush, grind, magnetically separate. After three-stage crushing, coarse ore can be dry-cobbed on a dry magnetic separator to reject barren waste before grinding, saving mill energy. The ore is then ground in a wet ball mill closed with a high weir spiral classifier to liberate magnetite, and upgraded over several stages of a wet drum magnetic separator. Two or three magnetic cleaning passes typically lift the concentrate to 62-68% Fe. Browse the full magnetic separation equipment range to match drum intensity to your ore.

Stage grinding paired with stage separation is the efficient way to treat magnetite. Rather than grinding everything to final fineness in one pass, the ore is ground coarse, the liberated magnetite is pulled out on a first magnetic stage, and only the locked middlings are reground. This staged approach removes liberated concentrate early, cuts overgrinding and lowers overall mill power. Typical final grinds run 80-95% passing 200 mesh on fine-grained magnetite, but the exact target is set by the liberation curve from testwork, since over-grinding wastes energy and generates slimes that hurt downstream cleaning.

The number of cleaning stages is a grade-recovery decision. More cleaning passes raise concentrate iron grade and lower silica, but each pass can shave a little recovery, so the circuit is built around your concentrate specification and pellet-feed or sinter-feed target.

Hematite and weakly magnetic ore

Weakly magnetic hematite will not respond to low-intensity drums. It is treated with wet high-gradient magnetic separation, gravity concentration on a spiral chute separator, or reverse flotation to remove silica, often in combination. Choosing dry or wet separation is itself a key decision; our guide to wet vs dry magnetic separation explains the trade-offs in moisture, power and recovery.

Closing the circuit

Final concentrate is dewatered to transport moisture on filters, while thickeners recover process water and thicken tailings for storage. Typical results are a 62-68% Fe concentrate at 70-90% iron recovery, depending on ore type and liberation, framed against your own testwork rather than promised. For a representative build, review our 2,000 t/d iron ore magnetic plant in Kazakhstan. As an EPC+M+O contractor, Xinhai delivers flowsheet design, in-house manufacturing, construction and operator training as a single source. To size a plant to your deposit, contact us for an ore test.