利用攀钢提钒尾渣制备富钒渣的研究

以攀钢提钒尾渣酸浸得到的溶液为沉钒母液,研究了外加FeSO4·7H2O、沉钒pH值、沉钒温度、沉钒时间对沉钒率和富钒渣质量的影响。最佳沉钒工艺条件为:常温下,不外加FeSO4·7H2O,直接用碱调pH值至4.5后,反应5 min,此条件下,沉钒率达到99%以上,富钒渣中V2O5品位为16%。沉钒后得到的富钒渣中主要为Fe(OH)3沉淀和少量Al(OH)3沉淀,钒吸附或夹杂在氢氧化物沉淀胶体的表面。富钒渣返回焙烧研究表明:富钒渣的返回量占钒渣原矿的15%时,可以促进钒的浸出,且相较于提钒尾渣直接返回焙烧能减少渣的返回量,降低设备负荷和能耗。

铝灰还原富钒渣制备钒铁合金的研究

为解决钒铁合金制备成本高和有价金属收得率低等问题,提出以铝灰作还原剂直接还原富钒渣制备钒铁合金的新思路,研究了不同还原条件对铝灰还原富钒渣过程中有价金属收得率的影响。结果表明,还原温度由1773 K升高至1873 K,Fe收得率由51.8%增加至95.6%;Mn收得率由16.7%增加至84.2%;Cr收得率由2.5%增加至87.9%;V收得率由0.5%增加至91.8%。二元碱度由1.0升高至1.5,Fe、Cr、Mn、V的收得率分别由72.5%、51.7%、35.8%、11.4%增加至95.6%、84.2%、87.9%、91.8%。最佳还原条件下(温度1873 K,二元碱度1.5,还原时间30 min)制备的钒铁合金中Fe和V的金属品位分别为28.18%和35.01%,合金产品中V/Fe的质量比为1.24。

Oxidation process of low-grade vanadium slag in presence of Na_(2)CO_3

The oxidation process of low-grade vanadium slag in the presence of Na2CO3 was investigated by XRD,SEM/EDS and TG-DSC techniques.The results show that the vanadium slag is oxidized in a temperature range from 273 to 700 °C.Olivine phases and spinel phases are completely decomposed at 500 and 600 °C,respectively.Most of water-soluble sodium vanadates are formed between 500 and 600 °C.When roasting temperature reaches above 700 °C,the vanadium-rich phases of sodium vanadates can be obviously observed.However,at temperature above 800 °C,the samples are sintered.Most of the vanadium is enwrapped by glassy phase compounds which lead to the decrease of the leaching rate of vanadium.At the same time,the effect of roasting temperature on extraction of vanadium and characterization of leach residues were discussed.