Table 1 Synthesis conditions, chemical analysis and composition of the obtained precipitates
From: A study on the dissolution rates of K-Cr(VI)-jarosites: kinetic analysis and implications
| Synthesis | Initial conditions/mol L−1 | Elemental analysis/W % | Approximate formula | |||||||
|---|---|---|---|---|---|---|---|---|---|---|
| Fe2(SO4)3∙nH2O | K2SO4 | K2CrO4 | Fe(NO3)3∙9H2O | K | Fe | Cr/CrO4 | SO4 | H+Oa | ||
| S1 | – | – | 0.2 | 0.2 | 6.90 | 31.44 | 19.12/42.67 | – | 18.99 | [K0.95(H3O)0.05]Fe3.04(CrO4)1.99(OH)6.01 |
| S2 | 0.01 | – | 0.2 | 0.2 | 4.80 | 27.35 | 14.24/31.80 | 4.33 | 31.72 | [K0.61(H3O)0.39]Fe2.64[(SO4)0.24(CrO4)1.76][(OH)4.92(H2O)4.31] |
| S3 | 0.05 | – | 0.2 | 0.2 | 5.17 | 28.44 | 9.30/20.75 | 17.38 | 28.26 | [K0.66(H3O)0.34]Fe2.54[(SO4)0.91(CrO4)1.09][(OH)4.62(H2O)3.13] |
| S4 | 0.025 | 0.05 | 0.2 | 0.2 | 6.70 | 29.88 | 7.72/17.23 | 27.71 | 18.50 | [K0.86(H3O)0.14]Fe2.67[(SO4)1.23(CrO4)0.77][(OH)5.01(H2O)0.41] |
| S5 | 0.2 | 0.05 | 0.2 | – | 4.43 | 26.09 | 1.18/2.63 | 40.31 | 26.93 | [K0.56(H3O)0.44]Fe2.33[(SO4)1.88(CrO4)0.12][(OH)3.99(H2O)3.27] |
| S6 | 0.3 | 0.2 | 0.2 | – | 4.56 | 25.89 | 0.87/1.94 | 40.74 | 26.87 | [K0.59(H3O)0.41]Fe2.32[(SO4)1.91(CrO4)0.09][(OH)3.96(H2O)3.29] |
| S7 | 0.3 | 0.3 | – | – | 5.21 | 27.20 | – | 40.51 | 27.08 | [K0.67(H3O)0.33]Fe2.43(SO4)2.11[(OH)4.10(H2O)3.53] |