Behaviour of cesium and lithium during the precipitation of jarosite-type compounds

Abstract

End-member cesium jarosite [CsFe 3(SO 4) 2(OH) 6] and end-member lithium jarosite [LiFe 3(SO 4) 2(OH) 6] do not exist. Cesium-bearing potassium, sodium and rubidium jarosites were synthesized, however, with cesium contents > 2 wt% being noted in potassium jarosite. The cesium content of the jarosites increases with increasing cesium concentration in solution, and the order of cesiumincorporation is potassium jarosite > sodium jarosite > rubidium jarosite. Only trace amounts of lithium are incorporated in jarosite; the maximum obtained was ∼ 0.2 wt% lithium in potassium jarosite. The lithium content increases with increasing lithium concentration in the synthesis solution, but is nearly independent of the potassium concentration or the solution pH. Although some of the lithium may be structurally incorporated in the jarosite, most seems to be physically entrained.