Moma, one of the world’s biggest titanium mineral deposits, is located 160km from the city of Nampula in Mozambique, Africa. It is owned and operated by Kenmare Resources.
The mine contains the titanium minerals ilmenite, rutile and zircon, which are used as feedstock to produce titanium dioxide pigment. It started production of heavy mineral concentrate (HMC) containing these three minerals in April 2007. It produced 1,201,100t of HMC and shipped approximately 853,100t of finished products in 2020.
Kenmare carried out an expansion at the mine ten years ago to fulfil the growing demand for titanium dioxide feedstock in the market. The expansion was aimed to increase the design capacity of the mine by 50% while increasing the mine’s reserve estimate and annual production of HMC.
Construction work on the expansion began in December 2010 and the works were completed in December 2013. The expanded mine has a mine life of more than 100 years.
The first shipment of concentrated mineral sands was dispatched from Mama in Q2 2019, following the commissioning of the product stream in Q4 2018. The Moma mine had more than 1,420 employees at the end of 2019.
Moma geology and reserves
Moma contains several sand deposits, which include Namalope, Congolone, Nataka, Pilivili, Mualadi, Mpitini, Marrua, and Quinga North and South. Heavy surface mineralisation occurs in the sand units near Namalope flats and Tupuito high dune areas.
The HM sand deposits occur in a sequence of fine to medium grained and silty sands consociated with clay units. The mineralisation constitutes about 85% of ilmenite, 5% of zircon and 2% of rutile, with minute variations among the units. It also contains small quantities of monazite, staurolite and quartz.
The total proved and probable reserves of Namalope, Pilivili and Nataka zones were 1,584Mt comprising 2.7% of ilmenite, 18% zircon and 0.06% rutile as of December 2019.
Mining at the Moma titanium deposit
Titanium minerals at Moma are mined through dredging. The mining is carried out at Namalope flats, which was the first deposit mined. The dredges cut the ore at the surface level, causing the sand to slide into the dredge pond, which is nearly 800m-long, 300m-wide and 15m-deep.
A wet concentrator plant (WCP) collects the sand pumped by the dredges. Two trammels are used by the WCP to treat oversized materials while the underflow materials pass by the surge bin. Silica sand and clay tailings are separated from the HMC by spiral separators. The total sands mined consist of 5% weight of the HMC.
The HMC is transferred to mineral separation plant (MSP), where it is stored and processed.
Processing of titanium heavy mineral concentrate in Mozambique
The MSP uses magnetic, gravity and electrostatic techniques to extract titanium minerals from the concentrate. Ilmenite is a magnetic mineral, while rutile and zircon are non-magnetic.
Ilmenite mineral from the dried HMC is separated from rutile and zircon minerals with the use of high-intensity magnets.
Pure ilmenite is produced through electrostatic separation of the magnetic mineral. A downstream magnetic separation plant and a 50tph ilmenite roaster further improve the quality of the ilmenite.
Waste minerals from the non-magnetic ore are removed through wet gravity separation. Rutile is then separated from zircon by electrostatic separators.
Transportation of titanium minerals from Nampula mine
The final products are stored in a warehouse and loaded into a 2.4km overland conveyor system. The conveyor leads to a jetty located near a marine terminal, from where the products are ultimately transferred to a ship loader.
Transhipment vessel Bronagh J carries the loaded products to the customer’s ship located 10km offshore.
The on-site facilities at the mine include a 170km 110kV electricity transmission line, a sub-station, a rented 9.6MW diesel generator facility, an accommodation village, offices, laboratory, airstrip, water supply and sewage treatment plants are included in the on-site facilities.
Moma mine expansion
The expansion of Moma upgraded the capacity of the existing dredges, MSP, product storage facility and WCP.
The expansion added a new WCP, wet high-intensity magnetic separation (WHIMS) unit, an auxiliary ilmenite plant (AIP), a starter, and a dredge pond. The new WCP with a 2,000tph spiral feed capacity was installed at a new dredge pond, located on the Namalope reserve.
There are three types of WCPs in total, namely WCP A, WCP B and WCP C. WCP A has been mining the Namalope ore region since 2007 and will continue to mine until its move to the Nataka mine in 2025. With a throughput capacity of 3,250tph, WCP A accounts for roughly 53% of Kenmare’s concentrated capacity.
WCP B has been mining the Namalope ore zone since 2013 and has been moved in 2020. It was upgraded to increase its throughput capacity to 2,400tph in 2018. It has one dredge called Deirdre.
WCP C is the newest and smallest, with a throughput capacity of 500tph, reflecting one-fifth of WCP B and one-sixth of WCP A. The commissioning took place at the end of 2019 and the beginning of 2020 and the mining of a high-grade region of the Namalope ore zone is inaccessible to broader WCPs.
The company transferred WCP B to the high-quality Pilivili ore field, which is approximately 23km from Namalope, in 2020. This will allow Kenmare to produce 1.2Mt of ilmenite (plus co-products) of annual production from 2021.