The Namoya Project lies on the western edge of the Kibaran Mobile Belt (KMB). The KMB is an intercontinental mobile belt which was formed during the Mesoproterozoic between 1.4Ga and 0.9Ga when the supercontinent Rodinia was formed. The KMB is also known as a metallogenic province.

The Namoya Project, even though segmented into separate prospects, boasts one type of gold mineralisation style. The following deposit characteristics have been noted:-
-gold mineralisation hosted within quartz veins and quartz stockworks, striking in a northwestsoutheast direction;

- prevalence of tourmaline crystals within the quartz veins;

- deformation structures within the quartz veins, resulting in irregular sheets, nested vein sets, ladder veins and micro-veinlets, characteristic of shearing;

- no granitic intrusions in the immediate area of the Namoya orebody (as a possible source of tourmaline) although quartz porphyry intrusions have been intersected by drill holes at Namoya Summit and Muviringu signifying potential for a deep seated granitic body; and

- sericite/chlorite schists, sometimes with carbonates, indicative of a magmatic and hydrothermal processes.

The deposit characteristics are typical of the intrusion-related, tungsten/tin-associated type. This class of magmatic-hydrothermal deposits occurs within magmatic provinces best known for tungsten and/or tin mineralization. This type of deposit contains a metal suite that includes some combination of bismuth, tungsten, arsenic, tin, molybdenum, tellurium and antimony and contrasts with that found in more widely-developed goldrich porphyry copper deposits.

Mining operations are based on conventional drill and blast, load and haul mining techniques. Ore is drilled and blasted, and loaded by hydraulic excavators in backhoe configuration, with off highway dump trucks.

Excess RoM is stockpiled on the ROM pad, with low grade ore sent to the low grade stockpile, located approximately 400m from the RoM pad. Stockpiled RoM ore is sorted under a stockpile grade control management scheme, with stockpile reclaim undertaken by a front end loader, and then fed to the crusher as required. Waste material mined is hauled to close-by waste dumps.

Primary Crushing
ROM, delivered by 40t trucks, is deposited into a tipping bin fitted with an 800mm static grizzly to prevent oversize material from entering the system. A rock breaker has been installed to ensure that all +800mm feed ore is broken to -800mm size, in line with process specifications. From the tipping bin, the ore is fed onto a 150mm vibrating grizzly using an apron feeder from which the -800+150mm material is deposited into a jaw crusher, which reduces the -800+150mm material to a topsize of 210mm. The resulting -210mm material from the jaw crusher, together with the -150mm from the vibrating grizzly, is conveyed along a 1.5km conveyor belt to the secondary crushing plant.

Secondary and Tertiary Crushing
The -210mm material from the primary crushing plant is deposited onto the primary crushing stockpile whose residence time is 12 hours. The stockpile serves to provide backup plant feed against conveyor length surge and maintenance requirements of the primary crusher. The stockpile has two sets of reciprocating plate feeders (2 running, 2 on standby) which are designed to handle wet clay material as well as assist prevention of “rat holing” in the stockpile.

Ore is withdrawn from the primary crushing stockpile and fed into a rotary scrubber in order to remove clays from the ore. The scrubber is fitted with a 40mm trommel discharge screen which allows for the oversize material (-210+40mm) to report to the secondary cone crusher which reduces feed to 100% passing 40mm. The undersize material from the scrubber (- 40mm) reports to a 2mm vibrating screen from where the -2mm material is fed to the gravity section whilst the -40+2mm material is fed to the tertiary crushing circuit.

The tertiary crushing circuit crushes material from the secondary crushers as well as the - 40+2mm material from the scrubber to 100% passing 10mm. The crushed ore is discharged onto a double deck screen with a top screen cutting at 10mm and the bottom screen cutting at 2mm. The oversize fraction from the top deck (-40+10mm) is returned to the tertiary crusher. The bottom deck oversize fraction (-10+2mm) reports to the heap leach pad whilst the bottom deck undersize (-2mm) reports to the gravity recovery section.

Namoya process plant makes use of a hybrid leach design in which a heap leach operation works in conjunction with a gravity gold recovery operation and a CIL plant.

The objective of the gravity recovery section is to recover gravity-recoverable gold from the - 2mm size fraction. Feed material is pumped from the secondary and crushing circuit to a dewatering cyclone. The cyclone underflow then reports to one of two Knelson concentrators. The resulting concentrate reports to the gold room whilst the gravity tailings report to a desliming cyclone cutting at 150µm. The cyclone underflow (-2mm+150µm) gravitates to a dewatering screen from where the coarse (oversize) fraction reports to the heap leach pad. The -150µm fraction from the desliming cyclone, together with the undersize from the dewatering cyclone, report to a vibrating trash screen cutting at 800µm. The screen underflow is fed to a thickener feed tank where flocculant is added. The resulting mixture is then discharged ........