Project Overview

Project Setting

Coast Map showing Special Mining Lease

Special Mining Lease measuring 1,661 hectares is located within the Kwale Exclusive Prospecting License area of 56km2 and is located approximately 50km south of Mombasa, and 8km inland from the Indian Ocean.

The Project resource comprises two dunes that contain economically viable concentrations of heavy minerals, which are separated by the Mukurumudzi River. These are the Central and South Dunes. A third dune, the North Dune is not currently included in the Project.

Geology & Mineralisation

The Magarini Sands, which host the Kwale deposit, are of aeolian origin deposited as coastal dunes after conditions of intense erosion. The poorly stratified deposits form a belt of low hills running parallel to the coast. Heavy minerals (“HM”), mainly ilmenite, rutile and zircon, are concentrated locally and are abundant in some places. The deposits also contain a clay and silt fraction of about 24%.

The general stratigraphic sequence of the Kwale deposit, as seen below, is composed of brown sand at the surface, followed by orange or reddish sand, becoming more beige or pinkish at depth. The base of the deposit is weathered sandstone from the Mazeras Sandstone.

Typical Cross Section - Central Dune and Mineral Sands at Kwale

Typical Cross Section – Central Dune at Kwale

Mineral Resources & Ore Reserves Estimate

Location of Kwale Dunes

Location of Kwale Dunes

The Kwale Special Prospecting License comprises three mineralised zones, the Central, South and North Dunes, which occur as unconsolidated dunes. Only the Central and South Dunes form part of the Kwale Project.

The total Mineral Resources as at 30 June 2015 were estimated to be 143.0 million tonnes at an average HM grade of 4.4%. Within this, the Ore Reserve is estimated to be 110.4 million tonnes at an average HM grade of 5.0%. Mineral Resources and Ore Reserves are reported in compliance with the JORC Code (2012) standards and are summarised as follows.

Mineral Resources

The total Kwale Mineral Resources at 30 June 2015 are shown in the table.

Deposit Mineral Resource Category Ore In Situ HM HM Slime Oversize HM Assemblage
Ilmenite Rutile Zircon
(Mt) (Mt) (%) (%) (%) (%) (%) (%)
CentralMeasured54.5 3.37 6.2 25 0 55 14 6
 Indicated15.0 0.41 2.7 29 2 52 13 6
 Total69.4 3.78 5.426 1 54 13 6
SouthMeasured60.3 2.18 3.6 28 4 46 13 6
 Indicated13.3 0.45 3.4 26 4 47 13 6
 Total73.6 2.63 3.6 27 4 46 13 6
TotalMeasured114.8 5.55 4.9 26 2 51 13 6
 Indicated28.3 0.86 3.0 27 3 50 13 6
 Total143.0 6.41 4.4 26 3 51 13 6

Ore Reserves

The total Kwale Ore Reserves at 30 June 2015 are shown in the following table.

Deposit Ore Reserve Category Ore In Situ HM HM Slime Oversize HM Assemblage
Ilmenite Rutile Zircon
(Mt) (Mt) (%) (%) (%) (%) (%) (%)
CentralProved48.3 3.21 6.6 24 0 56 13 6
 Probable5.8 0.18 3.2 282 5213 6
 Proved & Probable54.2 3.39 6.2 251 56 13 6
SouthProved46.7 1.80 3.9 28 3 49 14 6
 Probable9.5 0.35 3.7253 4913 6
 Proved & Probable56.2 2.15 3.827 3 49 14 6
TotalProved95.0 5.01 5.3 26 2 54 13 6
 Probable15.4 0.54 3.4 26 3 50 13 6
 Proved & Probable110.4 5.54 5.0 26 2 54 13 6

Read the full 2015 Mineral Resources and Ore Reserves statement.

Mining & Mineral Processing

Summary

Plant Overview

The Kwale Project comprises the following major operational and ancillary components:

  • Dozer mining unit (“DMU”)
  • Hydraulic mining unit (“HMU”)
  • Wet concentrator plant (“WCP”)
  • Slimes and tailings disposal
  • Mineral separation plant (“MSP”)
  • Product storage and shipping
  • Power supply via a 14km 132 kV transmission line and substation
  • Process water supply from a water storage dam on the Mukurumudzi River and back-up aquifer sources

From the DMU and the auxiliary HMU ore is fed by slurry pipeline to the WCP where the slimes and tails are removed and a heavy mineral concentrate (“HMC”) produced. The HMC is delivered to the MSP for separation of the three valuable products – ilmenite, rutile and zircon. The products are road hauled to the dedicated Likoni port facility where rutile and ilmenite products are stored for loading to ships via a conveyor system. Zircon is containerised and exported through the existing Mombasa port container terminal.

A simplified process flow diagram is presented below.

Simplified Process Flowsheet

Mining Operations

D11 moving earth to the DMU

The Kwale dunes are amenable to the dozer trap continuous dry mining technique. For the first 5 years, the mine will operate at between 8 and 9 million tonnes per annum before increasing to 12.5 million tonnes per annum as the grade declines.

The ore is mined in 160 X 80-metre blocks using two CAT D11 dozers backed up by two CAT D10s and other ancillary mobile equipment and is fed to the DMU where extraneous vegetation and other foreign materials are screened out before the ore is slurried with water and pumped to the process plant. Subsequently the DMU has been supplemented with the introduction of the HMU that handles peripheral ore zones not amenable to dozer mining.

As each block is depleted, the skid mounted DMU is maneuvred to the next block to be mined.

Wet Concentrator Plant

Spirals in the Pretorius Concentrator Plant

The WCP is designed for a maximum feed-rate of 1,600 tonnes per hour and 120 tonnes per hour heavy mineral concentrate production. The plant feed rate is determined by the incoming ore grade and stockpiling requirements and limitations. At high feed grades (+5% THM) the feed rate is limited by the production of HMC, while at lower feed grades (-5% THM) the feed rate is limited by the tonnage presented to the rougher spiral stage.

The slurried ore passes through a vibrating screen to reject +4mm trash materials with the undersize reporting to the primary surge bin. The slurry is then subjected to desliming using cyclones to remove the fine clay/slimes present in the ore, typically 25% by mass. The deslimed sand is drawn from the secondary surge bin and fed to a four stage wet gravity spiral circuit comprising banks of rougher, cleaner and recleaner spirals to produce HMC and discard sand tails used to build the tailings storage facility (“TSF”) containing walls.

Sand Stacker in the TSF

The primary cyclone overflow, containing the slimes fraction, reports to the thickeners. Flocculent is added to aid settlement of solids to generate a suitable solids density in the thickener underflow for discharge to the TSF. Thickener overflow water is recovered and recycled back to process.






Slimes Disposal and Impoundment

Removal of slimes from the sand before spiral plant treatment is essential, and effected by two-stage hydrocyclone processing. This demands a high volume of process water (about 50 gigalitres per year), much of which is recovered for recycling. The slimy water is directed to two 38-metre diameter thickeners, dosed with a suitable flocculant, and then separated into clear overflow water and thickened underflow slimes. The underflow has 30% to 36% solids content, and is directed to the TSF for deposition, impoundment and solar drying.




















The MSP, located adjacent to the WCP, comprises the feed preparation circuit, the ilmenite separation circuit, the rutile dry circuit and wet and dry zircon circuits.

The plant operates at a maximum feed rate of 90 tonnes per hour from the HMC stockpile equating to a maximum annual production rate of approximately 455,000 tonnes ilmenite, 85,000 tonnes rutile and 32,000 tonnes zircon. Changes in the ore mineral assemblage will directly affect the proportions of these products.

Mineral Separation Plant

Mineral Separation Plant at Night

Heavy Mineral Concentrate and Zircon Sands

The MSP, located adjacent to the WCP, comprises the feed preparation circuit, the ilmenite separation circuit, the rutile dry circuit and wet and dry zircon circuits.

The plant operates at a maximum feed rate of 90 tonnes per hour from the HMC stockpile equating to a maximum annual production rate of approximately 455,000 tonnes ilmenite, 85,000 tonnes rutile and 32,000 tonnes zircon. Changes in the ore mineral assemblage will directly affect the proportions of these products.

The HMC is upgraded using a combination of gravity, electromagnetic and electrostatic methods to generate marketable products of ilmenite, rutile and zircon. The ilmenite and rutile products are produced in bulk for sale to international markets, while zircon is typically bagged and containerised for export.

Reject impurity streams are returned to the WCP for disposal with the sand and slimes tailings.

Likoni Marine Terminal

A bulk storage and shipping terminal has been established at Likoni, approximately 50km north of the mine site.

The ilmenite and rutile products are road hauled in bulk in conventional 30-tonne road trucks and discharged in the 80,000-tonne storage shed at Likoni. A mobile ship loader utilising conventional conveyor technology loads at a rate of 1,000 tonnes per hour into bulk carrier vessels moored alongside the dedicated wharf. Zircon, either bagged or loose, is containerised on site and exported via the container terminal in the port of Mombasa.

MV African Eagle and the Shiploading Facility

Supporting Infrastructure

Base Titanium has constructed and commissioned an 8.5 million cubic metre water supply dam on the Mukurumudzi River to provide for its process water requirements of about 20,000 cubic metres per day. The surface water supply is back up by a bore field comprising 4 bore holes capable of supplying 5,000 cubic metres per day.

Mukurumudzi Dam

Electrical energy is supplied via a purpose built 14km 132kV power transmission line and substation. Power demand to run the operations is 9MW.

Connecting access from the main coastal highway to the mine site is by way of 8km sealed road built by Base Titanium.

To see how the project was built go to – Development History