纸浆漂白过程流中非过程铁元素的表征(英文)

CHARACTERIZATION OF IRON(Ⅲ) HYDROLYSIS PARTICLES IN PULP BLEACHING PROCESS

以新制铁和陈化铁模拟纸浆漂白过程流中的非过程铁元素，研究了非过程铁元素存在颗粒的粒径大小和分布、表面形态和物象组成．研究发现，新制铁胶体颗粒以纳米级存在（210～250nm），并随体系PH值增加而增加，其密度和体积分布呈双峰分布．70℃水浴加热1h后，新制铁胶体颗粒粒径明显增加，PH13时达到1620nm．陈化铁颗粒粒径较大，高达10um。IR、XRD、SEM—EDS分析表明，以新制铁形式的非过程铁胶体颗粒没有结晶成分存在，其宏观分子式为Fe29.1O17.2（OH）52．9；以陈化铁形式存在的非过程铁胶体颗粒主要以Fe2O3晶体存在，其宏观分子式为Fe34.7O38.8（OH）26.5。

.＂Fresh＂ iron（ III ） and ＂aged＂ iron（ III ） were used to simulate the existence of iron （ III） in pulp bleaching process. Particle size and distribution, phase composition, morphology, and structure of the particles precipitated from ＂fresh＂ iron（ III） and ＂aged＂ iron（ HI ） were examined. Particle size of ＂fresh＂ iron（ III ） was nanoscale, 210 nm to 250 nm,and just a small increase with the increase in pH. And density and volume distribution of ＂fresh＂ iron （ III ） presented a bimodal distribution. The particle size of ＂fresh＂ iron（ III ） with water bath at 70℃ for 1 hour was larger than 250 nm, and reached 1 620 nm at pH 13. Particle size of ＂aged＂ iron（III） was largest, about 10 um. The results of IR, XRD and SEM-EDS revealed the hydroxide and oxides formed in iron（ III ） hydrolysis and aging process. ＂Fresh＂ iron（ III ） in hydrolytic process didn＇t crystallize, and macroscopic molecular formula could be taken as Fe29.1O17.2 （OH）52.9. Crystal Hematite was formed in ＂aged＂ iron（ III ） and macroscopic molecular formula could be taken as Fe31.7038.8 （OH）26.5.