For every 100 units of indium metal mined along with zinc ores, only ~15 to 20 units is recovered as refined metal
Source: derived from Schwarz-Schampera and Herzig (2002) and Mikolajczak (2009)
and Herzig 2002).
Brunswick 6 and 12 mills reportedly recovered recovery of only 58.9% of In in Zn concentrate (Schwartz-Schampera and
At Toyoha, the recovery of indium in zinc concentrates was ~96% (same as estimated for zinc recovery in zinc
byproduct indium producers.
To allow for some upside, indium recovery in mine concentrates is estimated to fall be50%–70%.
The remaining 80%–85% that is not immediately recovered as indium metal and remains
associated with other elements and impurities as residue accumulates in tailings and other
dumps. These resources could be available for recovery at a later stage if prices and costs justify
Although smelters are locked into current technologies, as they become due for rebuilds or
upgrades newer technologies may be introduced that could significantly increase the recovery
rate. For example, according to the NI 43-101 compliant
Preliminary Assessment for Adex
recovery efficiency of indium is expected to be 83.05% (wt%) at the point of zinc concentrate
and 75.4% (wt%) when indium is recovered in sponge form containing ~95% purity indium
at the point of zinc concentrate for Argentex’s planned development of the Pinguino deposit in
Argentina (Gray et al. 2011) and 81% at the point of crude metal at South American Silver’s
Malku Khota deposit (Armitage et al. 2011).
The overall recovery of indium in zinc concentrates could thus conceivably be 75%–85% in the
medium term. Such an increase would by itself increase the overall indium recovery rate from
14%–20% (Figure 18) to ~21%–24%. Assuming a further recovery efficiency improvement in
new smelters of 90% efficiency (as implied by the Mount Pleasant estimate) the overall recovery
increases from 21%–24% to 38%–43%. Finally, assuming a further increase in recovery
efficiency from 80%–95% at the refinery stage increases the overall indium recovery efficiency
NI 43-101 (or National Instrument 43-101) represents the Canadian standard for reporting economic and mineral resource
This is the minimum specification for feed to conventional electro-refining circuit (Thibault et al. 2010).
The short-term supply curves presented earlier represent the quantities of indium currently
available at prices sufficient to cover variable production costs. The medium-term curves that
follow embody several adjustments:
Capital costs are included. Because operators have the option to invest in new capacity
eliminate all realizations in the simulation that would not generate positive returns for
Variation in the long-term main-product average prices is used in assessing
Figure 28 in 2011 U.S. dollars as indicated. More detail regarding how this is performed
is included in Appendix D.
Recoveries reflect latest commercially available technologies.
Quantities reflect current production capacity and quantities contained in mineral
Using the projected byproduct indium supply levels summarized in Table 12, as well as the
potential improvements to recovery efficiency details in Section 4.2, we generate a series of
medium-term supply scenarios. Briefly, these are:
Base case 2016. Based on current levels of recovery efficiency, 2011 production (731
associated indium recovery.
Adjusted 2016, base case + improved recovery and pipeline efficiency (2016). Uses
Section 4.2. This is similar to the approach taken in generating short-term primary supply
scenarios. But because we now consider the medium term, capital costs associated with
these efficiency improvements are reflected in the cost of indium.
Base case 2031. Based on current levels of indium recovery efficiency, 2011 production
Adjusted 2031, base case + improved recovery and pipeline efficiency (2031). Per the
Figure 19 contains the supply curves for the base cases. Compared to the primary supply curve
shown in Figure 11, the cost curves have shifted upward because capital costs are now included.
In the medium term primary indium supply seems to be elastic at prices of $350–$450/kg and
inelastic at prices higher than $800 and lower than ~$275.