Two main types of mineralisation are recognised at Blanket mine, namely disseminated sulphide replacement reefs (“DSR”) and quartz-filled reefs and shears.

DISSEMINATED SULPHIDE REPLACEMENT REEFS
DSRs host the best grades and comprise the bulk of the ore shoots. These zones have a silicified core with finely-disseminated arsenopyrite. Relatively high grades are found in a package of silicified biotite chlorite schist with irregular quartz stringers and disseminated and stringer arsenopyrite in the fabric planes. Due to lesser silicification, abundant biotite characterise the margins of these mineralised zones and as a result they have a lower gold content. Disseminated sulphide-replacement Mineral Deposits range up to 50 m in width with a strike of between 60 m and 90 m. Free-milling gold constitutes up to 50% of the total metal content with the remainder locked in the arsenopyrite. The ore is not refractory despite its association with arsenopyrite. Generally, plant recoveries in excess of 90% are achieved.

- QUARTZ-FILLED REEFS AND SHEARS
The second type of mineralisation is the quartz-filled reefs and shears. Two quartz shears are mined at the Blanket Mine: the Blanket Quartz Reef and the Eroica Reef. These reefs have long strikes, however, they are not uniformly mineralised. Continuous pay shoots of over 100 m on strike are not present. The Quartz Reef at the Blanket Mine has a surface strike of approximately 500 m, but economic mineralisation is restricted to three 90 m long shoots which were defined on surface by the early workers (AGS 2006). Quartzfilled reefs display a much wider grade range compared to the DSR deposits. On average, these shears are of a higher grade and are used in blending the ore to the mill. Dominant ore minerals are native gold and galena although arsenopyrite becomes more prevalent below the 470 m elevation.

Wall rock alteration typically comprises silica-pyrite-muscovite within a broader carbonate alteration halo. Quartz-carbonate altered rock forms the most commonly recognised alteration assemblage.

The deposits may have a vertical extent of up to 2 km, demonstrate extensive down-plunge continuity, and lack pronounced zoning. The ore mineralogy is dominated by gold, pyrite and arsenopyrite. Subordinate minerals such as galena, chalcopyrite, pyrrhotite, sphalerite, tellurides, scheelite, bismuth and stibnite also occur. Sulphide mineralogy commonly reflects the litho-geochemistry of the host rock with arsenopyrite being the most common sulphide mineral in metasedimentary host rocks and pyrite or pyrrhotite being more typical in metamorphosed igneous hosts. The gangue and alteration mineralogy is dominated by quartz and carbonate (ferroan dolomite, ankerite, siderite, calcite) with subordinate albite, fuchsite, sericite, muscovite, chlorite and tourmaline

Blanket Mine uses mining methods that are commonly employed and well-understood by greenstone belt miners who generally have to deal with steep shear- hosted to massive mineral deposits. Since the nature of the mineral deposits varies, the exact mining practices are tailored to suit the specific attributes of each particular mineral deposit.

The main mining methods utilised at Blanket are:-
• underhand stoping in the narrow mineral deposits; and
• long-hole stoping in the wider mineral deposits.

Stoping preparations in narrow orebodies (less than 3 m wide) begin by mining raises at 10 m intervals along the haulage. These are usually mined from the footwall of the orebody to 10 m above the haulage drive. The extreme end raises are equipped as ladder-ways while the rest have boxes constructed under them. In wider orebodies, draw points are mined instead of boxes.

The wider orebodies are mined using long-hole open stoping methods which produce bigger rock fragments than the conventional methods. At the end of these draw point crosscuts, draw point raises are pushed 10 m to the above coning level. The draw point cross cuts are also mined at 10 m intervals along the haulage.

Where the orebody widths are less than 12 m the haulage is mined in the footwall of the orebody with draw points mined at 10 m centre-to-centre intervals from the footwall Haulage to the hanging wall contact. Raises are then mined from the ends of these draw points to the coning level. The draw points are mined 3 m wide and 3 m high.

Just as in the narrower areas the extreme end raises are equipped as ladder-ways. In both cases, a sublevel drive is then mined off the central raise to connect all raises laterally. These raises, one central and two at the ends, are then mined from the cone drive connecting all levels above. Additional sublevels are cut between levels after which the orebody is fully developed and ready for stoping.

Stoping commences by slyping around the central raise, on the cone level to expose the footwall and hanging wall contacts and will continue in retreat fashion 5 m either side of this raise.

Coning will then commence by blasting into the slot taking the full width of the orebody. The cone progresses down to approximately 3 m above the main level. As soon as the coning retreats a safe distance from the slot raise, to ensure men are safe from the rocks falling from above, a new stope is commenced at the central raise on the level above. This process is repeated on the sublevels above until a sufficient number of stope faces are in production above the cones to provide the required production tonnage.

The Blanket gold Plant consists of a conventional crushing, milling and CIL, batch elution and smelting configuration with a current capacity of 40 ktpm. The crushing and milling circuits are designed to process RoM. However, the CIL and downstream circuits were designed to treat tailings dam material at a rate of about 110 ktpm (or 3,800 tonnes per day). More recently, historic tailings and RoM were treated in the CIL plant at a combined rate of approximately 100 ktpm to 120 ktpm. The tailings treatment was stopped about three years ago. The CIL is currently used exclusively for treatment of RoM at a rate of 30 ktpm to 35 ktpm. The retention time in the CIL circuit is as high as 72 hr as a result of the lower tonnage throughput.

The plant consists of the following circuits:-
- jaw crushing;
- cone crushing in closed circuit with a screen;
- primary rod mill in open circuit;
- ball mill in closed circuit with cyclones;
- gravity circuit;
- dewat ........