Iron Ore

 

Project Name:

LIGANGA
map Click on map to enlarge

Location:

Located within the Ludewa District of the Iringa Region.

Area:

24.66km2

 

 
   
   
   
   
   
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Access:

The area is located approximately 200km south of Njombe town and is accessible from Dar es Salaam by a major tarmac road through Songea to Magingo (1,380km) and then a gravel road to within 3km of the licence area.

The towns of Songea and Njombe are large, well populated and serviced town connected to the National Grid used.

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Geology:

The licence lies 8km along strike from the titaniferous magnetite ore deposits of Liganga, which are largely found to be cropping out along the four northwest – southeast trending hills, namely; Maganga-Matitu Hill, Maganga Hill, Mahenye Hill and Liganga Hill. These deposits are hosted within lenticular (in plan) luecogabbro. This body, based on previously geological mapping, extends into the licence area. During a site visit made in early 2008 magnetite and hematite-rich float observed within the northeastern sector of the licence.

Titaniferous magnetite ore deposits outcropping on Liganga Hill

Titaniferous magnetite (of the Liganga deposits) is a hard dense type rock which is strongly magnetic. The ore bodies have sharp delimiting contacts with the host country rock, anorthosite, and in places with chlorite schist. The average mineral composition has been indicated by volume as follows: -

Magnetite 53%
Ilmenite 22%
Spinel 10%
Chlorite 13%
Garnet/Pyrite 2%

In terms of chemical composition, the analysis of ore samples from Liganga and Maganga hills conducted by Lurgi Chemie of Germany (1984), produced the following results: -

Fe2O3 51.4% MgO 4.80%
TiO2 12.9% Al 2O 3 8.90%
V2O5 0.49% MnO 0.20%
CaO 0.01% Ni 0.10%
SiO2 0.90% Cr 0.20%

 

The Liganga Deposits and the National Development Corporation (NDC)

The National Development Corporation (NDC) is an economic development organization under the Ministry of Energy and Minerals established as a statutory corporation by an Act of Parliament in 1962, with the mandate 'to initiate, develop and guide the implementation of economically viable projects in partnership with the private sector'.

The intention of the NDC is to develop the area to the northwest of the Obtala licence, which as mentioned previously, is an extension of the same lithology. Referred to as the Liganga Iron Ore Deposit the area is reported as having various geological surveys and studies undertaken during 1898, 1900, 1948, 1952, 1956, 1957 and 1984.

The ore deposits at Liganga/Maganga Hills have been a subject of economic interest for many years. Early studies on the deposits indicate that the Liganga/Maganga Hills are rich in iron oxide (51-63%), vanadium oxide (0.5-1.7%) and titanium dioxide (13%) contents and are estimated to be between 200 and 1200 million tones. However, only 45 million tones of these reserves have been proved through drillings.

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Commodity Uses

Titanium dioxide

A non­toxic, powdered white pigment used in paint, plastics, rubber, and paper, approximately 4 million tons of pigmentary TiO2 are consumed annually worldwide. Titanium metal is resistant to corrosion and has a high strength­ to ­weight ratio and is used in the manufacturing of aircraft, marine and spacecraft equipment.

The pigment form is used extensively in plastics and other applications for its UV resistant properties where it acts as a UV absorber, efficiently transforming destructive UV light energy into heat.

Titanium oxide is also used as a semiconductor.

Vanadium

A soft and ductile, silver-grey metal. It has good resistance to corrosion by alkalis, sulfuric and hydrochloric acid. Approximately 80% of vanadium produced is used as ferrovanadium or as a steel additive. Other uses include:

  • In alloys such as specialty stainless steel, in rust resistant and high speed tool steels, mixed with aluminium in titanium alloys used in jet engines and high-speed airframes
  • Vanadium steel alloys are used in axles, crankshafts, gears, and other critical components.
  • It is an important carbide stabilizer in making steels.
  • Because of its low fission neutron cross section, vanadium has nuclear applications.
  • Vanadium foil is used in cladding titanium to steel.
  • Vanadium-gallium tape is used in superconducting magnets (175,000 gauss).
  • Vanadium pentoxide V2O5 is used as a catalyst in manufacturing sulfuric acid (via the contact process) and maleic anhydride. It is also used in making ceramics and glass manufacturing.
  • Electrical fuel cells and storage batteries such as vanadium redox batteries.
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