The SB-40 concentrator retains the highest density particles from a feed slurry to periodically produce a small but relatively higher-grade concentrate (up to 1% by mass).Concentrate grades can be very high, often measured in percentage of metal, i.e. 3% Au, etc. The high grades obtained mean that weight recovery is very low, usually <1%. Operating at up to 200 G’s, this product range produces an intermittent stream of concentrate at a maximum mass pull of <1%. Fluidization water is required.