The Ranobe Resource has been the subject of over US$20million of exploration and evaluation expenditure since it was discovered by World Titanium Resources in 1999.
Initial exploration work in the Toliara area was carried out in 1999 and resulted in mineralised sands being identified Ranobe as well as further north at Ankililoaka, Basibasy and Morombe. Further drilling was undertaken in 2000, 2001 and 2003 by which time the resource at Ranobe had been defined.
Exxaro Joint Venture
The Ranobe Mine was the subject of a complete Prefeasibility Study and an incomplete Bankable Feasibility Study carried out by Exxaro Resources Ltd (Exxaro) from 2003 to 2009 and a considerable amount of work has been completed. This includes resource definition (JORC compliant resources) and feasibility study standard reports for mining, processing, infrastructure, environmental and social matters.
Exxaro studied the Ranobe project in great detail, defining it in terms of using the deposit’s ilmenite as feed material for its existing smelter operations in South Africa. The feasibility study highlighted a portion of the deposit containing a JORC compliant drilled resource of 710 million tonnes at an average grade of 6.3% heavy minerals, to be mined using large scale dredging, similar to the east coast South African operations of Richards Bay Minerals. Approximately US$17 million was spent by Exxaro on the preliminary feasibility study and components of a bankable feasibility study, including the establishment of a Mineral Resource estimated in accordance with the JORC Code.
A large-scale dredging operation at Ranobe to provide smelter feed for a South African smelter did not meet Exxaro’s investment criteria and, given the adverse global economic and Madagascan political conditions at the time, Exxaro terminated the joint venture with WTR in July 2009.
Following the exit of Exxaro in 2009 a comprehensive review of the project was undertaken and sought a revised development concept for a mine at Ranobe to supply ilmenite, zircon and rutile onto the world markets.
The primary objectives for the review were;
- Focus the initial development on the high grade area within the Ranobe deposit
- Utilise simple mining and separation methods and utilise off-the-shelf equipment
- Leverage existing infrastructure, for example the port at Toliara
- Secure the long term potential of the Toliara Sands project by proving the viability of mine development and operation
The review identified a new development concept. A dry mine would produce ore which would be mix with water into slurry and pumped to mobile concentrators. After loading into road trains the HMC would be hauled ~40km to a transfer pumping station located on the north side of the Fiheranana River on a dedicated haul road and pumped via a 14km slurry pipeline to an MSP located at the existing Toliara port.
Two ilmenite products and a zircon (75%) and rutile (15%) rich non-magnetic concentrate would be produced in the MSP. The existing Toliara Port would be used to load barges with ilmenite for transfer into bulk vessels inside reef protected water and the zircon rich exported in containers via the existing wharf which was under-utilised.
Tails from the MSP would be returned to the mine site via the pipeline and road train and disposed of in the void.
The revised project concept delivered robust economics from the initial development while retaining scope for further expansion. Based on this positive outcome a Definitive Engineering Study (DES) was undertaken from late 2011.
Definitive Engineering Study
The DES, managed by TZMI with Engineering & Project Management Services as the lead engineering contractor, was completed in August 2012. Specialist sub-contractors were engaged for various aspects of the study, including the mine and mining method, port, haul road and slurry pipeline.
The study built on the earlier TZMI scoping study and Exxaro feasibility studies. The objective of the study was to;
- Undertake sufficient engineering for the mine, processing equipment and infrastructure to ensure the capital and operating cost estimates were robust;
- Determine the preferred mining method;
- Optimise the number and location of processing plants;
- Investigate opportunities to improve export logistics;
- Identify any long lead items;
- Review the Mineral Resource, develop an optimised mine plan and determine an Ore Reserve; and
- Prepare for the tender for project engineering design, procurement and construction management.
The experience of local and international engineering firms, operating in Madagascar, was incorporated to make sure that the costs used in the project economic model reflect the reality of actual in-country costs
The DES confirmed that a low capex, low technical risk and simple mineral sands operation could be built using proven technology.