Project Details
Legacy stockpile over 220Kt with a very low head grade of 43.7% Fe and 28% Silica.
Implementation of Oretech advanced sorting technology resulted in 53.9% Lump upgraded by 10% Fe
Geology
The Roper Bar iron deposit is located ~540km SSE of Darwin with ship loading operations located at Bing Bong port.
The deposit consists of interbedded siltstone. Mudstone, fine-grained sandstone and pisolitic ironstone with relatively thin beds of higher-grade hematite. Adjacent sediments are subject to iron alteration resulting in a gradation distribution of iron
Mining generated very-low & low-grade stockpiles not suitable for blending with the operations direct shipping ore (DSO). These low-grade stockpiles were determined be Fe cut-off grade, and therefore consisted of highly mixed, poorly sorted lithologies with varying degrees of Fe alteration. The feed head grade for the ore sorter was a complex and unpredictable arrangement of these lithologies.
Aim
To beneficiate a 150Kt low grade ore stockpile to produce a lump blending stock for higher grade lump ores
Scope
The scope of the operation was to crush historic low-grade stockpiles and process through the ore sorter to produce a blending product
Processing
- 220Kt tonnes crushed at +10mm -30mm sizing for 128.9Kt lump
- 10kt of crushed lump fed through the ore sorter
Result
The Fe feed grade was highly variable ranging from 36.8Fe through to 50.4Fe, reflecting the highly variable and transitional nature of the iron.
Processing of the lump through the ore sorter generated a 52.9%Fe lump product from stockpiles that would have remained unviable.
Ore sorting had a very positive upgrade on the three (3) major components of iron ore. – Fe, SiO2 and Al2O3.
Ore sorting had a significant impact on iron and silica at +9.7%Fe and -11.3%SiO2.
- 111Kt crushed lump fed through ore sorter
- 22.5% relative increase in Fe @ +9.71% actual
- 39.3 relative reduction in SiO2 @ -11.35% actual
- 24.7% relative reduction in Al2O3 @ -0.88% actual
- 48.3% product yield