Laserfiche WebLink
• <br />• <br />0 <br />IA <br />1.2 <br />1A <br />U <br />OA <br />0.4. <br />OZ <br />OA <br />A2 <br />-OA <br />-0A <br />-0a <br />4.0 <br />Sb(OH)5° '••.• <br />(aq) •. <br />Sb(O <br />TSbO+ Sb(OH)6,(aq) <br />Sb(OHY (aq) <br />. <br />•• Sb(OH)a <br />(a4) <br />0 2 4 6PH 8 10 12 14 <br />Pon & Do-pH Maw - tbt ahem Sb-O-H d VC end 1 Om <br />Figure 3 suggests that the neutral Sb(+3) species (Sb(OH)30), which is dominant over the <br />pH range of most natural waters, will be more mobile than the Sb(+5) species, which is <br />negatively charged and would tend to adsorb to positively charged mineral surfaces. <br />Antimony Pure Phase Minerals <br />Most pure phase antimony minerals are very soluble and are only present at very high <br />aqueous concentrations of antimony. The most common phases are Sb2S3 (stibnite) and <br />Sb2O3 (senarmontite)(Baes and Mesmer,1976; Wilson et al., 2004), both of which are in <br />the more reduced Sb(+3) oxidation state. Sb2S3 occurs under relatively high sulfide and <br />antimony concentrations and the most common occurrence is within ore deposits. <br />Formation of antimony sulfide within natural waters is rare, but may be possible under <br />sulfate-reducing conditions if the concentration of antimony is high enough. Polack et al. <br />(2009) found that SbM is reduced to Sb(III) by sulfide, resulting in precipitation of