The Island Gold Mine is an Archean orogenic gold deposit. It is a structurally hosted quartz-carbonate vein system situated within the Goudreau Lake Deformation Zone (“GLDZ”), a major regional brittle-ductile structure. The host terrane is a sequence of felsic to intermediate volcanic rocks of the Wawa Assemblage which are in the greenschist metamorphic range as is common for this class of deposit.

Gold mineralization in the Goudreau-Lochalsh area is not restricted to any rock type with the general exception of the later intruded north-west trending Matachewan diabase dykes which show no evidence of mineralization. Deposits may be hosted by one or several rock types, with past-producing mines and numerous other gold occurrences in the area exhibiting a close spatial association with felsic, intermediate and even mafic intrusive rocks.

Alteration within the Island Gold deposit is characterized by the presence of intense silicification, sericitization, carbonatitzation and pyritization. Pyrite content is typically 2% to 10% in disseminated form and less commonly as millimeter scale discontinuous stringers. Accessory alteration minerals may include tourmaline, apatite, epidote, chloritoid and local garnet in the deeper levels. The alteration occurs primarily in linear south dipping envelopes which can pinch, swell and anastomize in thickness between decimeter scale to over 8 m in thickness. There appears to be a gradual change in alteration with depth as silicification becomes more dominant. The alteration envelopes are termed Alteration Package Island (“API”) in mine geology nomenclature.

Within the wider envelopes of strongly deformed, sheared, altered rock previously described narrower zones of mineralized lenses
containing quartz carbonate veins contain economic gold. Quartz veins commonly bear visible gold (“VG”) and generally speaking, the majority of the gold content of the mineralized intersects will be contained in the quartz veins, with lower grade material in the surrounding altered more pyritic footwall and hangwall host rocks. Within the veins, VG forms clouds of fine gold droplets up to 3 mm in diameter but metallurgical studies indicate that generally free gold flake are less than 25 microns in diameter. Generally, the degree of veining appears to become more robust at depth, transitioning from a more stringer style quartz-carbonate vein on scales between millimeter and decimeter to larger scale veins over 4 metres in width, such as vein development seen on the 800 metre level and elsewhere at depth.

Of all the methods tested since mining activities commenced at the Island Gold Mine, the longitudinal long hole retreat mining method is the most productive and least costly, and is more commonly known as the Modified Avoca Mining Method. The ore width, vertical dip, good ground quality, productivity factors, costs, availability of equipment and personnel were some of the major parameters involved in the decision.

Before any stope mining can be carried out, a 4.5 m wide and 4.5 m high ramp is developed from level to level by jumbo drilling. Ore development is completed on levels approximately 22 m to 25 m apart vertically, sill to sill and is carried out by jumbo drilling. The ore drives are 4m wide by 4m high. All ore development headings are controlled by the geology department with width drift dimensions maintained at 4 m in width by 4 m in height.

LONG-HOLE STOPING METHOD:
Long hole mining consists in drilling a series of sub-vertical holes in the ore from one level to the other. The ore is then blasted in vertical slices. The ore is retrieved from the bottom drift using remote scoop trams. For every horizontal sublevel (approximately 22 to 24 m apart sill to sill), a primary slot (V30) is excavated at the extremity of the stope and blasting of a first stope, 18 m in length, is achieved following a longitudinal retreating fashion. All the broken ore is extracted before another blast is taken to ensure maximum ore recovery should any unplanned caving occur. Once the stope is empty, waste rock is used to refill the opened excavation as non-cemented rock fill. To create space for blasting of the second stope on the same sublevel, a void is pulled as a primary opening. The second stope is then blasted, mucked and backfilled. The process is repeated until the entire sublevel is mined out.

For the future sill pillars below the 740 metre level, the use of cemented rock fill may replace waste rock. The purpose is to allow for greater long-term stability and to allow for a higher ore pillar recovery. Cemented rock fill has not been used to date, but the necessary equipment has been purchased.

ALIMAK STOPING METHOD:
The alimak stoping method consists of using an alimak climber as a means of development and production drilling instead of conventional horizontal development.

The process starts by driving a raise along the height of the stope that will serve for secondary support and production drilling access. The raise dimension will typically be 3 m x 3 m.

Once the raise is completely driven, either by breaking through on the upper level or not breaking through if no overcut is planned, the raise screening is installed.

The next step consists of drilling and installing secondary support. For Island Gold, the support will consist of cement grouted cable bolts.

Production drilling is conducted on a horizontal axis on both side of the raise. The blasting sequence consists of taking horizontal slices followed by void mucking only. Once the entire stope is blasted, continuous mucking can begin. Maintaining the stope filled with blasted material allows for better dilution control.

Once mucking is completed, backfilling with run-of-mine waste completes the production cycle. To keep backfill from running in adjacent stopes, pillars are planned between each stope.

This mining method has not been used to date at Island Gold but is part of the current Life Of Mine (“LOM”) plan for one area of the mine.

The Island Gold Mine ore is processed at the Kremzar Mill. The mill is composed of a two stage crushing section followed by a two-stage grinding section. The mill uses cyanide leaching and a carbon-in-pulp process to recover gold. Some improvements were made to the plant in recent years such as replacement of crushers, cyclone replacement, and piping and pumping upgrades.

The ore from the stockpile is crushed by a jaw crusher followed by a secondary cone crusher. The crushed material is then sent to a ball mill operated in closed circuit and with cyclones and a regrind mill. Gold is leached in a leaching circuit and extracted in a carbon in-pulp (“CIP”) circuit. The loaded carbon is washed with a nitric acid solution to remove scale before being sent through a carbon regeneration kiln. Gold is removed from the loaded carbon by elution (stripping) followed by electrowinning. The stripped carbon is regenerated in reactivation kilns before being returned to the process. Fine carbon is constantly removed and recovered from the process to avoid gold loss, while fresh carbon is continuously added to the process. The high grade electrowinning concentrate is sent to a bullion furnace for smelting of doré bars.

The ore from the mine is stockpiled. A haul truck transports ore from the stockpile to a grizzly. A primary conveyor (CV-01) conveys the material to the coarse ore bin. A vibrating feeder feeds the coarse ore to the jaw crusher, the crusher discharge falls onto the screen feed conveyor (CV-02). The crushed ore is screened and the oversize goes to the cone crusher to be reduced and goes back to the screen feed conveyor (CV- 02). The undersize of the screen is conveyed to the fine ore bin by conveyors (CV-05/06).

The crushed ore is sent to the primary ball mill where it discharges to the primary ball mill discharge pump box. The pulp is pumped to the cyclone to be classified; the underflow is split between the primary ball mill and the regrind ball mill. The regrind discharge is send to the primary ball mill discharge pump box. The cyclone overflow is sent to a static trash screen and pumped to the thickener. Cyanide is added to the primary ball mill discharge pump box to start the leaching reaction in the grinding circuit.

The pulp from the thickener underflow is pumped to the leaching tanks train where five leaching tanks are supplied with compressed air. The pulp is directed to a vibrating trash screen prior to the CIP circuit where carbon is added to CIP tanks to adsorb the gold in solution.

The tailings from the CIP circuit are collected in a pump box and pumped to the tailings pond. Water from the tailings pond is pumped back to the plant to be reused as reclaim, gland seal and process water.

When the gold adsorbed on carbon reaches the right level, the carbon is recovered by screening. The screened carbon is directed to the stripping vessel to be eluted transferring the gold from the carbon surface to the pregnant solution. The pregnant solution is directed to the electrowinning cells and the carbon is directed to a rotary kiln to be regenerated.

The pregnant solution from the elution process is pumped to the electrowinning cells to precipitate the gold into a gold sludge. The gold sludge is decanted, dried, smelted and poured into gold bar.