The Trinidad silver-gold deposit at the San Jose Mine is a typical low-sulfidation epithermal deposit according to the classification of Corbett (2002), having formed in a relatively low temperature, shallow crustal environment. The deposit is characterized by structurally controlled hydrothermal breccias, crackle breccias and quartz-carbonate veins hosting silver-gold mineralization plus trace to minor base metal mineralization.

Precious metal mineralization at the San Jose Mine is hosted by hydrothermal breccias, crackle breccias, quartz-carbonate veins and zones of sheeted and stockwork-like quartz-carbonate veins emplaced along steeply dipping north and north-northwest trending fault structures.

The Trinidad vein system (Tv) is emplaced in the footwall fault zone of the extensional system hosting the mineralized vein systems at San Jose. The Trinidad vein system strikes 355° and dips 70° to 80° to the east-northeast. The vein system ranges from less than 1 meter to locally over 15 meters in true width, with higher grade mineralization generally being present in zones with greater widths. Significant portions of the Trinidad structure are characterized by late black matrix silicified fault breccias with only trace to weak mineralization. Higher grade precious metal zones in the Trinidad vein system range up to approximately 1,300 g/t Ag Eq across the width of the vein. Combined copper, lead and zinc values are generally less than one percent but locally higher concentrations are present. At approximately the 1,100 meter elevation in the central portion of the Trinidad Deposit, four drill holes intercepted higher grade base metal mineralization with combined copper, lead, and zinc values ranging up to 21.6 percent across the width of the vein system. Fault gouge seams are commonplace at the footwall and hanging wall of the Trinidad vein system. The Trinidad hanging wall splays and the Trinidad footwall veins are considered to be part of the Trinidad mineralized structure.

The Bonanza vein system (Bv) is emplaced in the hanging wall zone of the structural corridor hosting the mineralized vein systems in the Trinidad deposit. The Bonanza vein system generally strikes 350° and dips steeply to the east to sub-vertical. The Paloma vein (Pv) is considered to be part of the Bonanza vein system. Mineralization within the Bonanza vein system is present in the form of shoots plunging shallowly to moderately to the north-northwest, reflecting the dominant dip-slip movement of the controlling fault structures. Combined copper, lead and zinc values for the Bonanza Vein range from negligible in the upper portions of the vein system to approximately 0.1 to 0.5 percent at depth.

The Trinidad North discovery refers to an area located between 1846200N and 1847800N and below the 1200 meter elevation. Brownfields exploration in the Trinidad North area has been successful in identifying high-grade silver and gold mineralization associated with the northern extensions of the Bonanza and Trinidad vein systems and associated stockwork zones. Similar to the main Trinidad deposit, the mineralization is directly associated with the presence of hydrothermal breccias, crackle breccias and sheeted and stockwork-like quartz veinlets.

The Fortuna vein (Fv) strikes north-south and in contrast to the other major veins in the deposit, dips steeply to the west. The Fortuna vein has been extensively mined on levels 2, 3 and 4 of the historic mine workings with vein widths ranging from 2 meters to approximately 5 meters.

The main Stockwork Zone is located between 1846550N to 1847200N and 1,000 masl to 1,300 masl, being located in an extensional environment between the principal Bonanza and Trinidad structures. The main Stockwork Zone is present over 650 horizontal meters and 300 vertical meters being elliptical in shape, with a variable thickness ranging to greater than 50 meters. Stockwork-style mineralization is also present in the Trinidad North area between the Trinidad and Bonanza structures.

The primary silver bearing mineral in the Stockwork Zone is acanthite, usually in association with traces of pyrite. Secondary minerals accompanying the acanthite are silver-rich electrum, fine grained galena, sphalerite, chalcopyrite and gangue minerals including hyaline quartz, white quartz, and calcite along with minor concentrations of adularia and fluorite.

The mining method applied at the San Jose Mine is overhand cut-and-fill using a mechanized extraction methodology. Production capacity has been 3,000 tpd since June 2016 as a result of a mill expansion.

The method chosen for underground mining is overhand cut-and-fill which removes ore in horizontal slices, starting from the bottom undercut and advancing upwards. When ore widths are greater than 8 m, a combination of overhan cut-and-fill and room-and-pillar methods has been selected as the most appropriate for the conditions encountered.

Mechanized mining uses a Jumbo drill rig to drill blast holes, scoop trams for loading and trucks for ore haulage. Rock support is provided through rock bolts and shotcrete. The deposit width ranges from 4.5 m to 17 m for the Bonanza and Trinidad vein systems and can be more than 30 m in the Stockwork Zone. Mechanized mining is regarded as the only methodology suitable for all veins based on the geological structure and geotechnical studies to date. The mechanized mining sequence includes: drilling (with a Jumbo drill rig), blasting, support, loading (by scoop
tram) and haulage:

1. Ore is extracted from the stope in horizontal slices that span the entire width and length of the stope using pivot cuts of up to ±15 % gradient.

2. After the stope has been mined out, voids are backfilled with paste or waste rock. The key performance indicators for this activity sets 85 t/h production rates for rock waste and 100 to 150 t/h for paste fill.

3. Drilling of horizontal slices is conducted in sections of 6 m by 6 m by mechanized jumbos which have a boom length of 5 m.

4. The blast pattern is charged with an explosive made up of emulsion and ANFO. The average power factor applied in the blasting is 0.45 kg/t for stopes. After the mine face has been blasted and ventilated, scaling of loose rock is conducted. This is an important phase of the mining cycle in terms of safety due to the risk of falling rock.

5. Mucking is done by scoop trams (6 yd3 capacity) from the face to an underground stockpile in the stope. Trucks with 14 m3 capacity transport the broken ore from the stopes to the surface stockpiles using a paved ramp which allows speeds of up to 25 km/h.

6. Required support is defined by the Geomechanics Department.

Expansion of the concentrate plant was successfully completed in June of 2016 taking the ore throughput capacity from 2,000 dry tpd to 3,000 dry tpd. The principal stages are follows:
1. Crushing
2. Milling
3. Flotation
4. Thickening, filtering and shipping.

Crushing at the San Jose mine is a dry process, where ore extracted from the mine is reduced in size from 406 mm to 12.7 mm to be fed to the mill.

The crushing process begins at the reception hopper, where ore from the mine is deposited. The ore is fed from the bottom of the hopper via a plate feeder into a jaw crusher that crushes the ore to a 102 mm product size prior to it being transported via conveyors to one 2.44 m by 6.1 m primary screen deck. The screen deck operates with one mesh of 35 mm opening. Material that does not pass through the 35 mm mesh is sent to a secondary crusher via a chute, where it is reduced to 25 mm and the product returned to the primary screen deck. The mater ........