Lewatit® MDS TP 220 is a macroporous, weakly basic resin with chelating bis-picolylamine groups attached to a styrene/divinylbenzene co-polymer. Its monodisperse bead size distribution combined with a small mean bead size results in improved adsorption kinetics and an approx. 25% higher copper binding capacity relative to Lewatit MonoPlus TP 220. Lewatit MDS TP 220 exhibits a very high osmotic and mechanical stability to meet the requirements of metal processing technologies. It is delivered in the protonated sulfate form and can therefore be used without pretreatment. Due to the smaller bead size a higher pressure sop factor has to be considered when dimensioning the vessel during process design. The increased sensitivity towards suspended solids requires efficient pre-filtration of the feed stream, e.g by convention sand filter or filter candles. At a pH of 2, heavy metal cations are removed from aqueous solution consistent with the following selectivity series: Cu2>>Ni2>>UO2>>Fe3>>Zn2>>Co2>>Cd2>>Fe2. Lewatit MDS TP 220 is especially suitable for the use in the following applications:- the purification of cobalt electrolytes (cobalt/nickel separation)
- the separation of nickel/copper for ferric solutions
- the recovery of copper from strongly acidic solutions (pH<2)
- the purification of chromium (III) baths (removal of heavy metals such as copper and nickel)
- the adsorption of heavy metals (e.g copper) from solutions containing strong chelating agents like EDTA
Whilst most metals are removed from the loaded resin with a conventional acid strip, copper can only efficiently be desorbed with ammonia solution.Information provided by Lanxess. |
