Project Summary

Essentially the Tengani deposit is an alluvial/ colluvial fine to coarse-grained rutile/ ilmenite deposit; lying on the Shire River flood-plain. The area is strongly faulted, belonging to the southern end of the East African rift valley system. It is the rift faults that have led to the down-faulting that caused the Basement derived sediments to be deposited in the Shire River valley.

The source of the titanium mineralization is anorthosite rocks within the Basement rocks – shown as the brighter yellow on the map (anorthosite is a calcium plagioclase rock). The titanium minerals are associated with the anorthosite as irregular blebs, lenses and pods of intergrown ilmenite and rutile surrounded by and including abundant garnet, sphene and pyroxene.

The titanium minerals are eroded out of the anorthosite and transported down tributaries of the Shire River. When these tributaries debauch onto the Shire River flood plain the sediment load is dropped (because the tributary gradient falls) and the coarse grained fraction (along with the heavy minerals) is deposited adjacent to the Basement hills. This has created an irregular band of heavy mineral bearing fine to coarse-grained sediments parallel to the Shire River, adjacent to rivers flowing off the anorthositic basement. Tengani is the biggest of these deposits in the area.

Geology of the Tengani Deposit

The photograph above is a typical ilmenite pod. The ilmenite appears to be an intergrowth with rutile, surrounded by very abundant strongly fractured reddish-brown garnet. The white rock is anorthosite.

The Tengani titanium deposit covers some 60-70 km2 and sits between the Ndiola and Chimbwimbwi rivers in the very southern tip of Malawi. It is centred on three rivers, the Namyala, the Namikango and the Nkhande. These rivers (which drain some tens of square kilometres) derive their sediment load from the adjacent basement anorthositic and gneissic hills. This sediment load contains an additional heavy mineral component (dominantly ilmenite, rutile and garnet) derived from the anorthositic rocks through erosion.

Although not proven, it is suggested that the sediment package may be as deep as 60 metres and that the bulk of this package is derived from the adjacent hills.

The rivers debauch onto and across the Shire River floodplain such that they generate a very complex sedimentary stratigraphy of older fan-glomerates and river channel sands, interwoven with much finer grained Shire River alluvial sediments (largely silty-sands and sandy-silts).

Tengani Resources

The Tengani resource consists of a core area of high grade alluvial, fairly coarse-grained rutile associated with ilmenite. This is surrounded by an outer area which has not been fully modelled for which the data is less reliable (shown as Total Area below). From the data available from La Porte the following resource tonnages for contained rutile are estimated for the top five metres of the orebody:-

Tengani – Indicated Resource Estimates for Rutile

Area (km2) Grade TiO2% Tonnes
Area A (red) 0.55 1.21 89800
Area B (blue) 1.604 0.86 216500
Area C (orange) 3.54 0.78 474900
Total area 20.25 0.72 1969000

Unfortunately little direct work was done on the ilmenite resource. However La Porte noted the ilmenite and rutile are present at a ratio of 6 – 8:1. Using a conservative ratio of 6:1 for ilmenite/rutile gives the following potential in situ ilmenite resource:

Tengani – Inferred Resource Estimates for Ilmenite

Area (km2) Grade TiO2% Tonnes
Area A (red) 0.55 7.26 538800
Area B (blue) 1.604 5.16 1299000
Area C (orange) 3.54 4.68 2849400
Total area 20.25 4.32 11814000

Garnet and zircon are present but have not been adequately evaluated.

A wire-frame model, (lower) and a conventional contour map (upper), shown in the diagram on the left rotated through identical angles clearly show the distribution of rutile over the top 5 meters of the deposit. The scale is in kilometres so it can be seen that the Tengani deposit is large. The view is north-northeast. The core area of Tengani is the orange mass centre-left of the contour plan.
Data results are derived from multiple sources and have been produced in a variety of ways. Some of the HM data was re-assessed by CDE and the results obtained compared well with other HM data.

The key short-coming of the data presented is the accuracy of the La Porte rutile data which is important to the project. It is known that La Porte Titanium had their own laboratory (at the top of the Chiradzulu Hill) and completed almost all of their own analyses. The degree of intergrowth between the ilmenite and the rutile is unknown but is certainly present and this makes separation difficult. It is suspected that La Porte had a Franz magnetic separator and they probably ground the material fine, doing a magnetic separation. Non-magnetic material that sank in dense liquid was probably called rutile with some check analyses intermittently carried out to confirm this.

Environmental

A preliminary Environmental Impact Assessment (EIA) has been concluded on the proposed mining venture at Tengani. The report confirms to date there are no fatal flaws which should concern the development of the Tengani project.

The key points highlighted are:

  • The pre-construction phase will involve acquisition of 20 square kilometres of customary land, and possible relocation of two villages, Nthumba and Nyanga.  However, the physical resettlement of the villagers may be done some 5 years later after commencement of the project.

The construction and mine development phase will mainly involve:

  • Land clearance for the various project infrastructures such as office block, processing plant, housing and water works including a pump station on the Shire River etc.
  • Over burden removal (soil stripping) over the mining site.

The EIA study has established a number of potential positive and negative impacts which can be expected as a result of the implementation of the various Tengani project activities.  A summary of the main potential negative and positive impacts and proposed mitigation /enhancement measures is contained in the main report.

The potential positive and negative impacts were assessed using various standard parameters.  The results show that the potential negative impacts of the project can easily be mitigated, and therefore managed and abated.  Based on these, an environmental management plan (EMP) has been prepared.

RECENT and FUTURE WORK

Based on the above information, the data available for Tengani shows significant potential for the development of a high grade rutile project, with longer term opportunity to grow the business. As the quality of some of the old data is questionable, work over the last two years has been aimed at collating and updating missing data to confirming the extent of the ore deposit. Details of the recent work concluded to date are contained in the “Downloads”

In parallel with this representative samples were evaluated by SGS in Johannesburg, South Africa and a very preliminary flow sheet was developed. However due to certain equipment limitations TTM propose to supply further samples to Mintek in Johannesburg, South Africa with the objective of firming up a flow sheet to maximize the recovery of payable minerals which meet typical international specifications for these specialty products.

Once this flow sheet information is available, a broad based capital and operating cost estimate can be prepared. All this information will then be combined into a Concept Document which should provide potential investors with sufficient information on the project to make informed decisions on its future viability.