Sn deportment within the diverse lithological units of the Hämmerlein skarn (Erzgebirge, Germany): implications for minerals processing

The Hämmerlein skarn in the Erzgebirge, Germany, is assessed according to its beneficiation potential. A modified approach for automated mineralogy is used to evaluate the economic potential of the compositionally complex Sn ore. The lithological units show significant differences in modal mineralogy and Sn deportment. Petrographic observations and data from automated mineralogy suggest a close spatial relationship between chlorite and cassiterite, possibly pointing towards a cogenetic relationship. The association of these two minerals may be advantageous for beneficiation. Chlorite can easily be detected by a near-infrared detector used in commercially available sorting equipment. Chlorite- and cassiterite-rich rock fragments may thus be identified and separated for further processing by conventional milling, gravity separation and flotation.