Canadian listed Argentex Mining Corporation’s (Argentex) wholly owned Pinguino project is
located in the Santa Cruz province of Argentina. Exploration is still at an early stage and
Argentex has focused on defining an NI 43-101 compliant resource for the upper oxide ores.
However, of interest to indium supply is the lower sulfide ores detailed in Table 15. Although the
resource estimate presented in Table 15 is not NI 43-101 compliant, it gives an idea of the size of
the potential indium resource.
Table 15. Potential Indium-Bearing Mineral Resource at Pinguino
(Gray et al. 2011)
Sulfide Pit Resource Including Additional Oxide Ores
* Despite the resource class terminology, figures do not represent an NI 43-101 compliant resource.
When using the metal prices adopted by Argentex in its preliminary economic assessment of the
zone, we calculate that indium comprises approximately 8% of total potentially recoverable
revenue contained within an open pit mine that would target the sulfide ores (Table 16).
Based on figures in Argentex’s preliminary economic assessment (Gray et al. 2011), we estimate
that if mined over an 8-year period, Pinguino could produce approximately 7.3 tpa at a total cost
of about $310/kg of refined indium metal.
(Gray et al. 2011)
Midpoint metal recoveries
Potentially Recovered Metal at Site
4.1.4 Pirquitas, Argentina
Silver Standard Resource Inc.’s (Silver Standard) wholly owned silver-zinc Pirquitas Property is
located in the Puna de Jujeña region of northwestern Argentina, in the Province of Jujuy. The
open pit mine was commissioned in 2009. The mine is at an elevation of 4,100 meters and is
accessible by two all-weather roads. Ore is crushed and treated onsite to produce a concentrate
via flotation techniques. The silver and zinc concentrates produced from the plant are then
shipped to various third-party smelters around the world (Silver Standard 2012).
Based on an average indium concentration of 2 ppm (Schwarz-Schampera and Herzig 2002) and
total resources of 39.8 million tonnes and reserves of 16.7 million tonnes (Board et al. 2011), the
total indium content of Pirquitas resources and reserves could be ~113 tonnes.
Although commercial production at Pirquitas was achieved on December 1, 2009, comments
made in Silver Standard’s NI 43-101 Technical Report (Board et al. 2011) lead us to believe that
indium is not currently being recovered at that site. Average indium concentrations reported in
the separate silver and zinc concentrates are 450 ppm and 1,000 ppm, respectively. Should these
concentrates be shipped to indium-capable smelters, when using anticipated medium-term
average smelter and refinery recoveries of 90% and 95%, respectively, total supply of refined
indium from Pirquitas could be ~15 tpa.
In 2013, 8.2 million ounces of silver and 27 million lb of zinc were produced and silver and zinc
production in 2014 is expected to be 8.2–8.6 million ounces and 25–30 million lb, respectively