Jarosite is a by-product generated by the Zinc industry during the hydrometallurgical process, contains predominantly Fe2O3, SO3 and alkalis with small amount of ZnO. Mineralogical evaluation indicate predominance of Natrojarosite [NaFe3(SO4)2(OH)6] along with gypsum [CaSO4.2H2O] in small amounts.
Many experiments were initially conducted to assess the possibility of use of this waste as a gypsum substitute, its use at certain lower levels showed that it could be useful for decrease in setting time to some extent. The investigative studies were extended to study the effects of use of different addition levels on Jarosite (Jarofix) on the properties of OPC, PPC and PSC and also assess the potential for saving on use of Gypsum.
The subsequent studies indicated the possibility of reducing the Cr (VI) levels in cements with the use of Jarosite, further investigative work was carried out to study the efficacy of reduction of Cr +6 (water soluble Cr (VI)) and the storage stability, at different additions of Jarosite in cement at 0.5%, 1%, 1.5% , 2 and 3 % (w/w). The Difference in Cr (VI) with and without the additions of Jarosite was analysed and monitored using UV-Visible spectrophotometer by 1,5 – diphenyl carbazide method at 540nm. Total chromium in cement and Jarosite was analyzed on inductively coupled plasma optical emission spectrometer (ICP-OES). . It discusses various effects of use of different addition levels of Jarosite in OPC, PPC and PSC in terms of potential for reduction in use of gypsum, effects on quality of OPC, PPC and PSC in terms of its setting characteristics, early and later age strengths and also the efficacy of reducing Cr +6 (water soluble Cr (VI)) of the Cements.