The Sierra Rutile Area 1 (the Gangama and Lanti Deposits and other deposits within SRL’s current operations in Sierra Rutile Area 1) consists of a series of prominent hills and slight undulations with an elevation range of 0.9 meters above sea level (masl) along the mangroves, to 322 masl with the highest point being at Gbangbama Hill. The existing dredge ponds and rutile deposits are situated around the Imperi Hills region on the western and south-western extent, with the Lanti and Gangama expansion situated within the alluvial plains and mangrove swamps to the north west. The hills in the region have relatively steep slope angles and form prominent features in the landscape. The majority of the area adjacent to the hills comprises undulating, broad expansive fluvial plains, becoming increasingly flat towards the mangrove swamp areas.

The local geology is described as Tertiary aged alluvial deposits overlying the Precambrian high-grade quartzo-feldspathic-garnet gneiss (charnockite). The SR Area 1 heavy mineral sands placer deposits are hosted in the Bullom sediments which were deposited following a Tertiary marine regression with seas levels some 100 m below current levels. Mechanical and chemical weathering liberated heavy minerals from the underlying Kasila Group which were deposited in pre-incised channels.

Estuarine and marine unconsolidated sediments are located to the west of the major watershed located within the centre of SR Area 1. In contrast, alluvial and elluvial sediments were deposited subaerially to the north-east of the watershed. Several cyclic sequences comprising poorly sorted clastic gravels overlain by sands and clayey silts are preserved. Hard lateritic inclusions are common but are generally associated with the upper portions of the sequence.

The heavy minerals are generally angular and display little evidence of transport over long distances or extensive reworking. Grades rapidly decrease downstream with sand replacing the argillaceous material within the matrix.

2019 was a year of major operational transition at Sierra Rutile. In February, Iluka decommissioned the dredge operation at the end of its life, as planned. This was followed by two major expansion projects being commissioned at Lanti and Gangama dry mines.

Currently dry mining: In-pit mining (Lanti), truck and shovel (Gangama).
[10/31/2019 Corporate Presentation, p. 41]

SRL has historically undertaken limited dry mining of small isolated deposits in fringe areas outside the larger economic deposits where dredge mining is used. The material was excavated and hauled to the nearest operating dredge pond where it was stockpiled in the dredge ponds to be processed with the dredged material (CEMMATS, 2012).
[March 2018 Environmental Assessment, p.17]

During 2019 Iluka completed projects doubling the capacity at both the Lanti and Gangama mining operations in Sierra Leone.

The doubling of capacity of both the Gangama and Lanti dry operations from 500-600 tonne per hour to 1,000-1,200 tonne per hour. [31/06/2019 QREV-Q2, p. 7]

The Gangama project involved the addition of mining fleet and construction of a second concentrator, duplicating the design of existing operations. Commissioning of the Gangama concentrator began in May and was operating at design capacity by June.

At Lanti, a second mining unit was added and the floating concentrator from the decommissioned dredge operation was beached and refurbished. Construction and commissioning activities were completed during August. Both projects were delivered on schedule and on budget.

Concentrator Plants at Lanti: DM1-Commissioned 2013; DM4 - Repurposed concentrator from dredge operations.
Concentrator Plants at Gangama: DM2:1 - C ........