Appendices 5-13 - Nautilus Cares - Nautilus Minerals

Zinc sulfide is the most soluble of all these metal sulfides and therefore will undergo
exchange reactions with all these metals to enhance Zn mobilization (Batterham,
1999; Tsang and Parry, 2004 and references therein).
3.3 Major cations in seawater elutriates
Dissolved Na, K and Mg concentrations remained unchanged from background
seawater concentrations throughout the 1,440 minutes of the Phase 1 experiment and
the Phase 2 temperature experiments (Tables 5 and 6, respectively). In the time
course experiment of Phase1 calcium concentration showed an initial rapid increase in
concentration of approximately 60%, paralleling the rapid initial metal release (Table
5). Figure 7 shows an increase in dissolution with increasing temperature which
corresponds to the trend of decreasing pH with increasing temperature (Figure 1).
This would suggest the presence of a readily soluble Ca mineral phase in the ore (no
mineralogy was available for this ore sample).
net Ca concentration (mg/L)
350
300
250
200
150
100
50
0
6 Deg 12 Deg 24 Deg
Temperature (Deg C)
Figure 7: Net Ca concentration in filtered seawater from 180 minute elutriation
at 6, 12 and 24 o C. (Note: 6 o C data from Phase 1 experiment).
3.4 Dissolved organic carbon in seawater elutriates
Dissolved organic carbon in Phase 1 experiment showed an initial increase in
concentration of approximately 30% compared to the blank seawater (Table 3). The
organic carbon may act as a ligand to complex some of the dissolved metals,
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