Mining & Processing Operations
The above is a schematic of the Kenmare Moma mining and processing operation.
The mining operation consists of an artificial, freshwater mining pond approximately 800m long, 300m wide and up to 15m deep. Mining is conducted by two 2,500 tonne per hour capacity dredges which extract mineral-bearing sands from the pond mining face. The mineral-bearing sands are pumped to the WCP where HMC is recovered by gravity separation. The products of the WCP are HMC and tailings. Tailings, which consist of a coarse fraction (sand) that settles immediately, and a fine fraction (slimes) that settle less quickly, are deposited at the rear of the mining pond where they are spread out for future rehabilitation. The concentrate comprises a mixture of the valuable minerals ilmenite, rutile, and zircon as well as some non-valuable silica and alumino-silicates. The concentrate, which represents approximately 5% by weight of the total sand mined, is pumped overland to the MSP where it is stockpiled prior to further processing.
The MSP is fed with HMC to produce a suite of ilmenite products, rutile and two zircon products. The MSP uses high-intensity magnets to separate the magnetic minerals (ilmenite) from the non-magnetics (rutile and zircon). This is followed by a wet, gravity separation process to remove low-density trash minerals (silicates), after which electrostatic separators are used to remove conducting minerals (rutile) from non-conductors (zircon).
A 50 tonne per hour ilmenite roaster and downstream magnetic separation plant has also been built to enhance the quality of the high titanium dioxide (TiO2) ilmenite product when required.
Final products are stored in a 145,000 tonne capacity warehouse under secure, watertight cover and with facilities for reloading products onto a 2.4 km long overland conveyor. The overland conveyor leads to a 400m long jetty which supports the product export conveyor and a walkway for personnel.
From the jetty, product is loaded onto the 4,000 tonne capacity selfpropelled product trans-shipment vessel Bronagh J., which transports mineral from the jetty to the trans-shipment point, where it selfdischarges into the customer’s vessel.
The mine also has other supporting infrastructure including a 170 km 110kV power transmission line, 6 MW of standby generation capacity, an accommodation village, offices, laboratory, airstrip, water supply, sewage treatment plants and roads.
The mine is expected to produce per annum, 800,000 tonnes of ilmenite and 18,000 tonnes of rutile, both titanium minerals, and 47,000 tonnes of zircon. The Mine is initially based on a 20 years operation at this level of production.
Wet Concentrator Plant
Dry Separation Plant
Moma will be a large volume and low cost operation. The key factors contributing to its low cost position are listed below:
- little or no vegetation
- sparsely to unpopulated high dunes
- no overburden
- fresh water for the dredge mining and processing
- moderate clay levels (3-12%)
- high (52-60%) TiO2 content in the ilmenite
- high value rutile and zircon co-products
- project will be served by low cost hydro electric power
- coastal position on favourable shipping route
- favourable taxation treatment by the Mozambican authorities
