Chrome Ore Processing Solution

The chromite ore challenge

Chromite is dense, roughly 4.5-4.8 specific gravity against silicate gangue near 2.7, which makes gravity concentration the natural recovery method. The complication is that buyers care about both Cr2O3 grade and the chromium-to-iron ratio, so an effective flowsheet must reject iron-bearing gangue as well as light silicates. Whether the ore is loose alluvial sand or massive hard rock changes the front end completely. Xinhai begins every chrome project with a bench and pilot test at its 3,000 m² mineral test center to fix the liberation size and the gravity-magnetic split.

Alluvial chrome

Alluvial and placer chromite is already liberated, so no grinding is needed. The feed is scrubbed to break down clay and screened to size, then concentrated by gravity. A jig recovers the coarse fraction cheaply, while a spiral chute separator and a shaking table recover the finer chromite that jigs miss. Our complete chrome ore processing plant packages scrubbing, screening and a staged gravity circuit into one mobile or fixed line. The full gravity concentration equipment range lets us match unit types to your particle-size distribution.

Matching the gravity unit to the particle size is what makes a chrome plant work. Jigs are most effective on coarse material, roughly above 0.5 mm, where they deliver high tonnage at low cost. Spiral chutes cover the intermediate fraction efficiently with no moving parts and low water use, while shaking tables give the sharpest separation on fine chromite down to around 0.1 mm but at lower throughput per deck. A staged circuit that hands each size fraction to the unit best suited to it recovers far more chromite than any single device, which is why we read the size distribution off the testwork before fixing the layout.

Hard-rock chromite

Massive or disseminated chromite must be crushed and ground to liberate chromite grains from the silicate matrix, but only as fine as necessary, since over-grinding produces hard-to-recover slimes. The liberated material then follows the same gravity route. For a grounding in unit selection, see our guide to gravity concentration equipment.

Raising the chrome-to-iron ratio

Gravity alone upgrades grade but does not always lower iron enough. A high-intensity dry magnetic separator removes iron-bearing gangue from the gravity concentrate, lifting the Cr2O3:Fe ratio toward the specification ferrochrome smelters require.

Closing the circuit

Concentrate is dewatered for transport and thickeners recover process water from tailings. Typical results are a 42-50% Cr2O3 concentrate at 70-90% recovery, framed against your own testwork rather than promised. For an example of how Xinhai delivers a turnkey plant end to end, review our EPC+M+O project case studies. 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.