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Currently, the commercial antimony metallurgy is mainly based on pyrometallurgical processes and oxidative volatilization of Sb2S3 is an essential step. This step includes the problems of high energy consumption and low concentration of SO2 pollution. Aiming at these problems, we present a new method of sulfur-fixing roasting of antimony sulfide. This method uses ZnO as a sulfur-fixing agent, and roasting with Sb2S3 was carried out at 673 K~1073 K to produce Sb2O3 and ZnS. By calculating the thermodynamics of the reactions, we can conclude that the Gibbs Free Energy Change (?G?) of roasting reaction is below -60 kJ/mol and the predominance areas of Sb2O3 and ZnS are wide and right shifting with the temperature increase, which all indicates that this method is theoretically feasible. The reacted products between Sb2S3 and ZnO indicated that the reaction began at 773 K and finished approximately at 973K. We used the Ozawa-Flynn-Wall, Kissinger and Coats-Redfern method to calculate the kinetics of the roasting reaction. The conclusion is as follows: The average values of apparent activation energy (E) and natural logarithmic frequency factor (lnA) calculated by Ozawa-Flynn-Wall, Kissinger and Coats-Redfern were 189.72 kJ?mol-1 and 35.29 s-1, respectively. The mechanism of this reaction was phase boundary reaction model. The kinetic equation is shown as follow, where ? represents reaction fraction: 1-(1-?)1/3 = 2.12 x1015 exp(-1.90x105/RT) t.

Zirconium isotopes have the potential to trace both magmatic differentiation and crustal evolution, as well as deep Earth processes. Zirconium is compatible in bridgmanite where it has a higher coordination number than in silicate melt, implying that Zr isotopes could be fractionated during magma ocean crystallisation. We report the Zr isotopic composition of 31 komatiites from around the globe, ranging in age from 2.41 to 3.55 Ga. The delta Zr-94/90 (per mille deviation of Zr-94/Zr-90 from IPGP-Zr standard) values for the komatiites are homogeneous at 0.030 +/- 0.049 parts per thousand (all errors are 2 s.d.), and consistent with associated basaltic rocks (0.048 +/- 0.032 parts per thousand). These results, identical within uncertainty of the bulk silicate Earth estimate from modern basalts, suggest that the mantle Zr isotope composition has been constant since at least 3.55 Ga. Combining the isotopic compositions of komatiites and basalts of all ages we suggest a conservative delta Zr-94/90 = 0.040 +/- 0.044 parts per thousand (n = 72) for the mantle composition. Several komatiite systems that we analysed in this study, including Schapenburg, Komati, and Weltevreden, have been previously argued to have isotope signatures consistent with magma ocean crystallisation processes. However, their Zr isotope compositions are indistinguishable from other komatiites, implying that bridgmanite crystallisation did not fractionate Zr isotopes to any measurable extent.

In order to understand the risk of polybrominated diphenyl ethers (PBDEs) existing in sediment for years, the accumulation of PBDEs in sediment aged for 2 years to fish was investigated. Simulated aquatic system microcosms were conducted with PBDE contaminated sediment aged for 2 years and carps were cultured in the microcosms for 20 days. PBDE concentrations in carp tissues were analyzed to estimate the bioavailability of aged PBDEs in carps. The main spiked PBDE congeners were detected in sediment even though the contaminated sediment was aged for 2 years. Similarly, the five PBDE (BDE-28, 47, 100, 153 and 154) congeners which probably were bioaccumulated by carp were detected in fish tissues, indicating that PBDEs could be bioaccumulated after aging for 2 years. The PBDEs distribution revealed that the concentrations of polybrominated diphenyl ethers in tissues of Cyprinus carpio is in this order of magnitude: gut > liver > gill > fillet. The PBDEs concentrations in fillet were as high as 67.9 ng/g dry wt, in which BDE-47 contributed almost 50% in profile.