The ore, it seems, breaks up naturally during handling with minimal oversize lumps.
ABx started trial mining at Bald Hill on December 9, digging up about 10,000 tonnes of bauxite for screening during February and early March.
The ore was free-digging using a medium-sized excavator.
Benching at 1.2m to 1.5m height allowed for good separation of bauxite ore and the other two layers – a detrital overburden layer and a clay transitional layer. Those other two layers held some bauxite nodules.
Those bauxite nodules from the detrital layer unexpectedly achieved saleable grade at some coarse size fractions. This discovery has ABx taking a closer look at the nodules from the transitional layer.
It turned out excavator operation initially crushed the ore too finely, but this got better as operator experience increased. A different bucket configuration in the last fortnight of the trial helped too.
Mining and screening achieved 300 to 400 tonnes per hour, which would equate to about a 900,000 tonne per annum output. This is almost double the 500,000tpa production rate the project had envisioned.
ABx is finalising lease contracts for a mobile equipment fleet and the specialised screening plant.
It says it has bought or leased about 90% of its capital items.
The slow-downs in iron ore and other mining sectors have significantly increased the availability of mining and transport equipment for leasing at competitive rates.
This availability had not been foreseen when ABx first announced capital cost estimates of $5.5 million to $12.5 million in 2012 and 2013.
Once all the components for the transport from pit to ship are working well, railing of bauxite to Bell Bay Port will start at 1100 tonnes per day. That will increase later in the year when shiploads double to 60,000t per month.
The company aims to start shipments midway through the second quarter.
Bauxite sold into China is achieving average prices of more than $A70 per tonne.
Sales contracts are being framed to coincide with the initial shipping arrangements and subsequent ramp-up in tonnes over the following 12 months.
ABx has more than $3.5 million free cash, excluding lease deposits and rehabilitation bonds.
The company has no debt and an undrawn line of credit from Noble Group.
On the exploration front, ABx has discovered two deposits at Nile Road and the Rubble Flat prospect. Each has the potential to replace more than 12 months’ production.
The bauxite deposits at both prospects remain open and further drilling is underway to test the extensions of Rubble Flat.
