The Lofdal property is underlain by Paleoproterozoic metamorphic rocks of the Huab Metamorphic Complex, which outcrop as an inlier of the Congo Craton surrounded by stratified rocks of the Damaran Orogen. The metamorphic basement was intruded at ca 750 Ma by alkaline silicate rocks and carbonatites of the Lofdal carbonatite complex. The complex comprises an early silicate intrusive assemblage of dominantly nepheline syenite, and a later carbonatite intrusive assemblage ranging from sovite through dolomitic and ankeritic carbonation.

The Huab Metamorphic Complex is polydeformed, affected by at least one phase of high-temperature isoclinal folding and is locally migmatised. The Huab Metamorphic Complex has not been directly dated but is considered to be about 2.0 billion years (Ga) old as it is intruded post-tectonically by the Fransfontein Granite, which has been imprecisely dated by U/Pb with two discordia lines giving ages of 1871 ±30 million years (Ma) and 1730 ±30 Ma.

Rocks of the Huab Metamorphic Complex were polydeformed and metamorphosed prior to intrusion of the Fransfontein Granite at about 1.7 Ga. They were subsequently affected by extensional tectonics during the rifting event that initiated the Damara Orogen at 850 Ma to 750 Ma and transpression during the orogenic events that accompanied the Damara Orogeny from 580 Ma to 500 Ma. The effects of both Neoproterozoic rifting and early Paleozoic transpression are recorded in the Lofdal carbonatites.

The Huab Metamorphic Complex in this area is dominated by quartzo-feldspathic gneiss and metasedimentary grey gneiss with lesser amphibolite and pegmatite. The gneisses strike approximately ENE-WSW and generally dip steeply southwards.

Mineralization in Areas 4 and 2B is structurally controlled and hydrothermal in origin. The host structures are first- and perhaps second-order basement structures that were apparently reactivated more than once during the mineralizing event. Repeated movement promoted the introduction of several generations of hydrothermal fluids, which resulted in a complex series of overprinting alteration events. The mineralization is dominantly present in xenotime and is interpreted to be related to the waning stages of hydrothermal alteration related to carbonation intrusion. The highest-grade mineralization does not occupy a consistent position within the structural zones. It is interpreted to occupy structures within the zone that were still open during the last phases of hydrothermal alteration. The mineralised structures can be traced from hole to hole and are variably mineralised.

The outline of the alteration zone is highly irregular at map scale. The intense alteration in the core is typically between 15 m and 30 m wide on the surface (not true width). The less intense alteration halo exhibits gradational and diffuse contacts with the wall rocks and is typically on the order of 50 m to 60 m wide at surface but can range to more than100 m wide. At the eastern side of Area 4, the fault zone bifurcates, with the main system branching in a slightly more northerly direction and a splay of the fault continuing in an ENE direction. There is alteration and mineralization associated with both splays, but the southern splay appears to decrease in intensity along strike and alteration appears to die out within a few hundred metres.

The mineralization in Area 4 occupies a structurally-controlled, linear alteration zone. The Area 4 alteration zone is the largest and best mineralised and is clearly manifested and easily mappable in surface outcrops by variably intense albitisation and brown carbonization with locally abundant phlogopite. Grab samples from outcrops typically return highly anomalous values of HREE and also have a very high HREE/TREE ratio.

The principal mineralization in Area 2 is the 2B zone, a wide zone of hydrothermal alteration and carbonatite intrusion. Like Area 4, the mineralization is characteristically enriched in HREE and samples throughout the alteration zone show a very high ratio of HREE to TREE. The mineralized zone has been traced in outcrop along a strike length of more than 600 m and remote sensing information and regional sampling results suggest that the zone may ultimately have a strike length of more than 3 km. The width of the zone in outcrop is variable. At its southern end, the width of the zone of alteration and carbonatization ranges from about 20 m to 35 m but thins to less than 10 m in the central section where it bifurcates into two separate zones. At the northern end, where the zone of alteration and carbonatization is again amalgamated, it is more than 60 m wide. In outcrop, it comprises a zone of massive carbonatite dykes, within a complex envelope of hydrothermal alteration and brecciation. The southern part of the zone is dominantly brown carbonatite and related alteration. Alteration zone lithologies include massive albitite, localized zones of green phlogopitic fenite, brown stained albitite breccias infused with carbonation, as well as altered mafic schist that has been carbonatized, variably albitized, and intruded by carbonate veinlets. Although massive and continuous across strike at its southern end, the zone bifurcates at surface in its central section with a hanging wall zone of dominantly carbonatite and related alteration and a footwall zone that includes considerable altered, carbonatized schist and carbonatized stockwork.

The proposed mining method is conventional open pit mining. Mineralised rock and waste would be drilled, blasted, loaded by hydraulic shovels and hydraulic excavators into off-highway dump trucks, and hauled to the processing plant.

The Main Zone of the Area 4 deposit would be mined at cut-off grade of 0.1% TREO which would require minimal in-pit grade control. Essentially, the entire mineralised zone would be mined. "Fine" in-pit grade control is expected to be difficult because of the nature of the mineralisation. The use of XRT after the crushing stage will deal with the separation of internal waste. It was therefore decided to not carry out a standard pit optimisation to guide the pit design.

Although testwork is still progressing at Mintek in Johannesburg, South Africa as well as Nagrom in Western Australia, this study compiled a flowsheet based on best data from testwork at the time of writing for a 2,500 t/d primary processing facility coupled to a remote xenotime cracking facility to remove radioactive thorium from the concentrate. The final concentrate will be shipped from the port of Walvis Bay, Namibia to processing facilities abroad.

The process plant will most likely consist of two locations with the primary beneficiation facility (Mill Site Process Plant) located at the mine site and the concentrate processing facility (Cracking Plant) located at the port of Walvis Bay. This will allow the key skills to be located in the town of Walvis Bay, which will facilitate easier attraction and retention of skills required for the relatively complex cracking facility. At present the calcite HCL leach facility is still located at the mine site but should this faci ........