硫铁矿烧渣水热法合成纳米球形α-Fe_2O_3

Nano sphere-shaped α-Fe_2O_3 synthesized hydrothermally from pyrite slag

运用XRD、TEM等测试手段,对硫铁矿烧渣水热法合成α-Fe2O3的工艺进行了研究。结果表明:硫铁矿渣的最佳酸浸工艺为加入理论量1.3倍的75%硫酸,在300℃下反应2h后用热水搅拌浸出,铁的浸出率高达93.94%。20℃时加入计量的沉矾剂,并用NH3·H2O调整浸出液pH值至2.50后加热至65℃反应2h,95.1%铁以铁矾形式析出。将析出的铁矾制成0.3mol/LFe(OH)3悬浊液,用5%NaOH调整pH值至11.30后,在搅拌速率600～700r/min、升温速率为2.5℃/min的条件下加热至(172±2)℃水热反应2h,得到粒度约为55nm的均匀球形α-Fe2O3。

The technical process of αFe2O3 synthesized hydrothermally from pyrite slag is studied by using XRD and TEM. The optimizing technical conditions for iron extraction are that the adding quantity of sulfuric acid(concentration:75%) is 1.3 times as much as the theoretical quantity and the reaction system is soaked in heat water for 2 h at 300 ℃,then the percentage of iron extracted from slag can reach 93.94%. In separating iron from the lixivium of slag,some reagent for alum deposition is put into the lixivium and the pH value is adjusted to 2.50 by using NH3·H2O at 20 ℃,then the lixivium is heated to 65 ℃ and the reaction is kept for 2 h,thus the iron obtained as the crystal of ferric alum can be up to 95.1%. In synthesizing hydrothermally αFe2O3,the suspension of 0.3 mol/L Fe(OH)3 is prepared from ferric alum and the pH value of the suspension is adjusted up to 11.30 by using NaOH(concentration:5%),then with the heating rate of the autoclave being 2.5 ℃/min and the stirring rate of the autoclave being 600~700 r/min,the reaction is kept for 2 h at (172±2) ℃,and αFe2O3 with uniform sphere shape and apparent dimension of about 50 nm is obtained.