锆冻胶压裂液的高温性能

本文用测定突破真空度的方法评价了无机锆冻胶压裂液的高温性能,研究了这种冻胶作为高温压裂液的各种影响因素。从对比实验证明,这种压裂液具有成本低、易配制、高温稳定、能自动破胶、破胶后残液无残渣,并有粘土防膨性能等特点,是一种理想的高温压裂液。     

从铌钽矿无磁尾矿中回收锆钍的研究综述(二)

本文综合报道了国内外从锆矿中制备氧氯化锆的各种工业方法以及生产与研究现状。     

表面活性剂辅助水热法合成纳米四方相氧化锆

以氯氧化锆和氨水为原料,十六烷基三甲基溴化铵做模板剂,在水热条件下制备纳米级四方相二氧化锆。由TG-DTA综合热分析,推断了氯氧化锆的热分解机理;通过X射线粉末衍射、透射电子显微镜对二氧化锆晶体的晶相组成、形貌及大小分别进行了表征。结果表明:借助十六烷基三甲基溴化铵的模控作用,经过250℃下18 h的水热处理即可制得结晶度较好,平均粒径20 nm,无明显团聚且以四方相为主的二氧化锆粉体。     

Effect of Zr and Ti on isothermal oxidation behavior of Nb–Si based alloys

The isothermal oxidation behavior of 56Nb-16Si-(20-x)Ti–3Cr–3Al-2Hf-xZr (x ?= ?0, 2, 5, 10 ?at. %) alloys was investigated at 800 ?°C and 1250 ?°C, respectively. The results show that increasing the Zr content evidently increased the oxidation rates at 800 ?°C, accompanied by the obvious occurrence of pesting oxidation. The alloys showed alike linear oxidation kinetics at 1250 ?°C. With the increase of Zr content, the adherence and integrity of oxide scales were improved, but the overall oxidation resistance was slightly deteriorated. The observed oxidation behavior may be attributed to the composition variation of Zr and Ti in the alloys. The oxidation mechanism associated with the composition variation is discussed in this study.