Ion-exchange of some elements in limestone, dolomite and chrome-iron ore.

An ion-exchange procedure is described for the analysis of dolomite, limestone and chrome-iron ore. In dolomite and limestone, calcium and magnesium are separated by eluting with 1M acetate buffer (pH 6) ; in chrome-iron ore, chromium(VI) is first separated from other metals by passage through a cation-exchanger, Dowex 50W-X8 (H+ form), when chromium(VI) is not adsorbed. Iron, aluminium and magnesium are subsequently recovered from the resin and are determined by conventional methods.