Factors Influencing the Sulfidation Rate of Fe-Mo Binary Alloys

The sulfidation rate constants of various Fe-Mo binary alloys in S2 vapor with different sulfidation parameters were collected to summarize the correlation between the sulfidation rate and alloy composition, sulfur pressure and sulfldation temperature. The octivation energies indicate that the sulfidation process of the alloys is exclusively controlled, at a given temperature, by one alloying component i.e. either Mo or Fe. The sulfidation rate declines exponentially with the increasing of Mo content in alloy. And the influence of sulfur pressure is relatively slight.

含钴三元硫化物常压硫酸浸出钴的动力学研究

开展含钴三元硫化物常压硫酸浸出的实验研究。考察搅拌速度、浸出温度、硫酸浓度和粒度对钴浸出率的影响,并分析从含钴三元硫化物中浸出钴的动力学。结果表明,在最佳条件下,钴和铁被选择性浸出,且浸出率均大于99%,而钼和铜则富集于浸出渣。通过对实验数据的分析可知,钴的浸出符合由固体产物层产生的收缩核模型,且浸出过程受内扩散控制。浸出反应的活化能为49.86k J/mol,硫酸浓度和粒度的反应级数分别为0.57和-1.4。

Al_(0.5)CoCrFeNi高熵合金高温腐蚀行为研究

采用真空电弧熔炼炉制备了Al0.5CoCrFeNi高熵合金(下标表示摩尔比)。研究了高熵合金在800、900℃的75wt%Na2SO4+25wt%NaCl熔盐中抗高温腐蚀性。利用带有能谱仪的扫描电镜和X射线衍射仪分析高熵合金的腐蚀层形貌、成分和组织结构。结果表明:高熵合金在熔盐中的腐蚀质量损失较严重,随腐蚀温度升高,抗腐蚀性下降;腐蚀层出现明显分层,合金表面生成了疏松多孔的NaFeO2等多种混合氧化物;合金腐蚀过程发生内氧化和内硫化,内层生成Al2O3、Cr2O3混合氧化物及Cr5S6硫化物。