湿法炼锌过程中赤铁矿生成及硫的吸附转化

Production of hematite and conversion of adsorption S in zinc hydrometallurgy process

赤铁矿法除铁工艺因渣含铁高,渣量小,无二次污染等特点备受国内外关注。硫含量是影响赤铁矿品质并实现其资源化利用的重要因素之一。本工作研究温度、时间、Na_2SO_4浓度、晶种用量、始酸浓度等因素对赤铁矿沉铁过程除铁率、亚稳态铁物相转变及硫吸附转化行为的影响规律。结果表明:升高温度、延长反应时间、添加晶种、降低始酸浓度、控制Na_2SO_4浓度可有效提高除铁率且有利于铁矾向赤铁矿转化,从而显著降低渣中硫含量,提升赤铁矿渣品质。在反应温度为180℃、反应时间3 h、氧分压0.4 MPa、晶种15 g/L、硫酸钠浓度为0.15mol/L的条件下,除铁率达到96%左右,渣含铁为65.8%,硫、钠的含量为1.42%、0.067%,获得了高品质的赤铁矿渣。

Hematite process with the properties of high iron content, small residue volume and no secondary pollution has been paid great attention in the whole world. Sulfur content is one of the most important factors which affect the hematite quality and its utilization as a resource. The effects of temperature, time, Na2SO4 concentration, seed addition, initial concentration of sulfuric acid on iron removal efficiency, conversion behavior of semi-stable iron phases and adsorption of sulfur were investigated in present work. The results show that the jarosite is more likely to convert into hematite and sulfur content reduces in precipitate with increasing temperature, time and seed addition, and reducing the initial acid concentration and controlling the sodium ion concentration. The high quality hematite precipitates, which are obtained at reaction temperature of 180 ℃, retention time of 3 h, oxygen partial pressure of 0.4 MPa, seed addition of 15 g/L and Na2SO4 concentration of 0.15 mol/L, contain 65.8% Fe, 1.42% S and 0.067% Na, and with iron removal efficiency of 96%