To separate Pb from PbSO_(4)-coprecipitated jarosite,a novel thiourea-induced freeze-thaw cycling(T-FTC)process was investigated.Results show that distributed PbSO_(4)particles are pressed and aggregated around the ja...To separate Pb from PbSO_(4)-coprecipitated jarosite,a novel thiourea-induced freeze-thaw cycling(T-FTC)process was investigated.Results show that distributed PbSO_(4)particles are pressed and aggregated around the jarosite particles by T-FTC.Under the freezing-concentration effect of T-FTC,the reaction between PbSO_(4)and thiourea is also promoted,forming lead thiourea sulfate(Pb-tu).As the cycles of T-FTC increase,PbSO_(4)around jarosite disappears for the reaction of forming Pb-tu.After 12 cycles of T-FTC,a spontaneous separation is observed between Pb-tu and jarosite,i.e.,Pb-tu is separated into the upper layer while jarosite-rich phases remain in the lower layer.Due to this spontaneous separation,leaching toxicity of the jarosite coprecipitates is reduced by 73.7%.These results suggest that T-FTC process can achieve the separation of Pb from PbSO_(4)-coprecipitated jarosite and is a promising approach for removing and recovering metals from iron-rich jarosite residues.展开更多
The practical synthesis of pseudonucleosides incorporating thiourea derivative by coupling of monosaccharides （D-glucose and D-galactose） per-O-acetylated glycosyl isothiocyanates and different heterocyclic hydrazid...The practical synthesis of pseudonucleosides incorporating thiourea derivative by coupling of monosaccharides （D-glucose and D-galactose） per-O-acetylated glycosyl isothiocyanates and different heterocyclic hydrazide derivatives is reported. The method involves the preparation ofper-O-acetylated glycosyl isothiocyanates from per-O-acetylated sugars （two-step synthesis）, which couple with heterocyclic hydrazides from amines to give thiourea-linked pseudonucleosides. All newly synthesized pseudo-nucleosides were assayed against human lung cancer-cell lines （PG） and human liver cancer-cell lines （BEL-7402） in vitro. The 6,6-dimethyl-benzothiophen-3-carbo-hydrazide-4-one pseudonucleosides showed moderate inhibition against these two cancer-cell lines with ECs0 from 22.8 to 76.4 mM and from 54.9 to 82.4 mM, respectively. And the other compounds did not demonstrate any significant cytotoxicity even at concentrations up to 200 mM.展开更多
基金financially supported by the National Natural Science Foundation of China(Nos.51904355,51825403)the National Key R&D Program of China(No.2020YFC1909201)。
文摘To separate Pb from PbSO_(4)-coprecipitated jarosite,a novel thiourea-induced freeze-thaw cycling(T-FTC)process was investigated.Results show that distributed PbSO_(4)particles are pressed and aggregated around the jarosite particles by T-FTC.Under the freezing-concentration effect of T-FTC,the reaction between PbSO_(4)and thiourea is also promoted,forming lead thiourea sulfate(Pb-tu).As the cycles of T-FTC increase,PbSO_(4)around jarosite disappears for the reaction of forming Pb-tu.After 12 cycles of T-FTC,a spontaneous separation is observed between Pb-tu and jarosite,i.e.,Pb-tu is separated into the upper layer while jarosite-rich phases remain in the lower layer.Due to this spontaneous separation,leaching toxicity of the jarosite coprecipitates is reduced by 73.7%.These results suggest that T-FTC process can achieve the separation of Pb from PbSO_(4)-coprecipitated jarosite and is a promising approach for removing and recovering metals from iron-rich jarosite residues.
文摘The practical synthesis of pseudonucleosides incorporating thiourea derivative by coupling of monosaccharides （D-glucose and D-galactose） per-O-acetylated glycosyl isothiocyanates and different heterocyclic hydrazide derivatives is reported. The method involves the preparation ofper-O-acetylated glycosyl isothiocyanates from per-O-acetylated sugars （two-step synthesis）, which couple with heterocyclic hydrazides from amines to give thiourea-linked pseudonucleosides. All newly synthesized pseudo-nucleosides were assayed against human lung cancer-cell lines （PG） and human liver cancer-cell lines （BEL-7402） in vitro. The 6,6-dimethyl-benzothiophen-3-carbo-hydrazide-4-one pseudonucleosides showed moderate inhibition against these two cancer-cell lines with ECs0 from 22.8 to 76.4 mM and from 54.9 to 82.4 mM, respectively. And the other compounds did not demonstrate any significant cytotoxicity even at concentrations up to 200 mM.
