East Coast Coal Project

Project Details

Our client brief was to understand if ore sorting could remove capital expenditure by removing down stream mineral processing by introducing ore sorting into their feasibility study and undertaking test work.

Background

Bulk ore sorting tests were undertaken at OEM test centre in Perth.

Two bulk samples consisting of ~230kg from processed stockpiles were evaluated.

Stockpile A
Stockpile C

Scope

Work consisted of undertaking feasibility works on 2 stockpiles, to confirm if ore sorting is viable to reduce the ash content using dry mineral processing and removing the requirement to process ore through the CHPP plant.

Processing Samples

Two sample batches from stockpile A & Stockpile C each sample size was 230kg.

The ash content (back-calculated) of Stockpile samples was 27%-32%. Stockpile C had a higher ash content (32%) than Stockpile A (27%).

Pre-screening of sorter feed to remove sub 10mm component was undertaken. The <10mm component is too fine for effective ore sorting. Pre-screening to remove <10mm fines also removes a high ash component (37%-48% ash) and reduces feed grade to 25% ash (Stockpile A) and 29% ash (Stockpile C).

Based on the ore sorter performance curves:

Stockpile A upgraded better than Stockpile C
Stockpile A indicated potential to achieve <15% ash at a low reject rate (~25%).
Stockpile C indicated potential to achieve ~17% ash at ~40% reject rate.
The coarse screened feed (31.5mm – 100.0mm) performed similar to the fine screened feed (10.0mm – 31.5mm) i.e. feed size (from 10mm up to 100mm) does not appear to influence efficiency of sort.

At an assumed 30% reject rate in a single pass sort:

the product from Stockpile A will be ~14% ash.
the product from Stockpile C will be ~18% ash.

At an assumed 40% reject rate in a single pass sort:

the product from Stockpile A will be ~13% ash.
the product from Stockpile C will be ~17% ash.

Ore sorting solutions