The Project’s tenements consist of 2 mineral leases (‘MLs’), 22 exploration licences (‘ELs’) and 18 exploration licence applications (‘ELAs’).
The MLs, ELs and ELAs cover a total area of approximately 14,430 square kilometres that span across the Roper Gulf Shire. The majority of these tenements remain substantially unexplored, and there may be significant upside potential from investing in further exploration activity.
In October and November 2014, AIR undertook a JORC compliant resource definition drilling and sampling program of ML27422 and SEL28291. The program was managed by a leading mineral sands industry expert, TZMI.
The resource within the ML27422 is known to contain several dominant mineralised units including pisolitic soil, clay sands, black soils, and weathered dolerite. Historic auger drill sample tests suggested high grade ilmenite which compares favourably with most commercial mineral sands operations in Australia.
A summary of the samples taken for the resource definition program are set out below.
Table 7 - Summary of drill holes and samples undertaken during the Q4 CY 14 resource definition program
The preliminary results from the drill program indicate a high quality low impurity TiO2 product can be produced with the resource potentially to support a 12 year mine life at 300,000tpa. A Resource Model and Competent Persons Report will be released in April 2015 with the outcome of the Q4 CY14 drill program. This will be made available to Potential Purchases in the Final Bid stage.
There may be further opportunity to ramp-up production and/or extend the life of mine by completing further exploration work on the ELs within the Proect Area. Indications are that the existing tenement portfolio has potential to provide ilmenite ore for up to a 50 year mine life.
In late 2011 the DME granted the primary mineral lease (ML27422) to undertake mining operations in accordance with the 2012 MMP. ML27422 permits the extraction and processing of 200,000 tonnes of ilmenite concentrate per annum, and is the only ML where mining activity has occurred to date.
Following construction of the processing plant and ancillary infrastructure, ML29042 was granted as an ancillary mining lease. The processing plant and the majority of the ancillary infrastructure is located on ML29042.
Aerial view of AIR site and ROM stockpiles
History of operations
AIR has adopted a shallow panel strip mining technique to extract the ilmenite ore for processing according to the pit mining campaign sequence in Figure 22.
The mine plan is intended to proceed in a north to south direction. Once vegetation is cleared, the shallow strips (200 metres wide, 300 metres long and a maximum of four metres deep) are excavated using earth movers (given the soft material and shallow depth of the ore, no explosives are required). AIR intends to mine the access lanes and vegetation buffers once all pits have been mined. To date AIR has undertaken one campaign and mined 1.5 blocks of the 62 blocks/strips.
Proposed Mining sequence
Air orebody has unique characteristics, including the high slimes content and the relatively pure heavy mineral assemblage. An optimised processing concept was developed based on industry standards for materials handling and processing, mineral sands processing techniques and TZMI knowledge and experience supported by testwork results.
The focus of the proposed flowsheet is the removal of slimes prior to gravity separation. This not only reduces the volume of material that has to be treated in the process plant, but will also mean that the separation efficiency will be greatly improved.
A simplified representation of the proposed process flow is shown in Figure
Simplified process flow diagram