Mineralization at Campo Morado mine consists of polymetallic volcanogenic massive sulphide deposits hosted within an upper Jurassic to lower Cretaceous sequence of felsic to intermediate flows, tuffs and fragmental volcanic rocks, and fine-grained sedimentary rocks. There is strong geological continuity of the mineralization as demonstrated in the extensive diamond drilling and underground development.

During Campo Morado’s last full production year of 2014 only zinc and copper concentrates were recovered using room and pillar mining methods, Telson is planning to restart mining operations employing block caving mining methods to potentially reduce mining costs with an emphasis on maximizing recoveries of all economic metals including gold, silver, zinc, lead and copper. Additionally, Telson is planning to focus mining activities to zones outlined within the defined resources where higher precious metal content is available.

After primary jaw crushing to minus 5 inches, ore is fed to the single SAG mill (9’ x 22’, 1,500 kW motor) operating in closed circuit with cyclones. Throughput and power is increased by adding 5” diameter steel grinding balls. The Bond Work Index is reported to be 14 kWh/t. Cyclone overflow is then passed to a Vertimill (VTM) with a 746 kW motor, also operating in closed circuit with cyclones, to achieve a target grind size of 80% passing 38 microns. High chrome ¾”
steel grinding media is used in the VTM.

The process plant was originally designed by Farallon to treat an average of 1,500 t/d of ore to produce selective copper, lead and zinc concentrates. However, the facility was upgraded, by Farallon/Nyrstar to treat an average of 2,200 t/d.

A carbon pre-float circuit (two tank cells) is utilised to remove carbonaceous material ahead of lead rougher flotation, which is pumped directly to the tailings dam. In addition, one of the lead scavenger cells is also used for this duty. This circuit was not required with the G-9 material previously. MIBC frother and SMBS (sodium metabisulphite) are used to float the carbon and depress the sulphides. The carbon reportedly contains about 2 g/t Au and can be considered pregrobbing for gold.

The ground slurry at 30% solids w/w passes to the lead roughing circuit, where flotation is conducted at the natural pH of about 6.5 – 7.0, i.e. very slightly acidic and with no conditioning. Aerophine 3418A collector with MIBC frother is us ........