攀枝花钒铁精矿钠化焙烧提钒新工艺研究

研究了焙烧温度、焙烧时间、钠化剂种类、配比等对攀枝花钒铁精矿焙烧的影响,得出了焙烧阶段最佳条件为焙烧温度为1 300℃、焙烧时间为120 min、Na2CO3含量为6%。试验结果表明,钒铁精矿采用钠化焙烧水浸提钒工艺,比火法提钒的回收率高,钒的转浸率能达到86.91%。

红格钒铁精矿提质降杂新技术研究

红格南矿区钒钛磁铁矿多为橄辉岩型矿石,其矿物组成种类繁多,矿物嵌布特征和结构构造较为复杂,其钒铁精矿产品TFe品位较低,仅为54.08%,TiO_2品位为12.55%,主要脉石矿物橄榄石和辉石。故本文针对该钒铁精矿开展了多种设备及工艺的试验研究,最终采用"细磨-深选"、"细磨-新型复合力场精选机精选"两种工艺方案为钒铁精矿合理的提质降杂工艺。在磨矿细度-0.038 mm 87.67%情况下,细磨-深选工艺可获得钒铁精矿TFe品位56.21%,回收率95.68%的指标;细磨-新型复合力场精选机精选工艺可获得钒铁精矿品位56.48%,TFe回收率97.33%,TiO_2品位11.88%的指标。该技术方案对于红格地区钒铁精矿的提质降杂具有十分重要的现实意义。

Behaviors of vanadium and chromium in coal-based direct reduction of high-chromium vanadium-bearing titanomagnetite concentrates followed by magnetic separation

The reduction behaviors of FeO·V2O3 and FeO·Cr2O3 during coal-based direct reduction have a decisive impact on the efficient utilization of high-chromium vanadium-bearing titanomagnetite concentrates. The effects of molar ratio of C to Fe n(C)/n(Fe) and temperature on the behaviors of vanadium and chromium during direct reduction and magnetic separation were investigated. The reduced samples were characterized by X-ray diffraction(XRD), scanning election microscopy(SEM) and energy dispersive spectrometry(EDS) techniques. Experimental results indicate that the recoveries of vanadium and chromium rapidly increase from 10.0% and 9.6% to 45.3% and 74.3%, respectively, as the n(C)/n(Fe) increases from 0.8 to 1.4. At n(C)/n(Fe) of 0.8, the recoveries of vanadium and chromium are always lower than 10.0% in the whole temperature range of 1100-1250 °C. However, at n(C)/n(Fe) of 1.2, the recoveries of vanadium and chromium considerably increase from 17.8% and 33.8% to 42.4% and 76.0%, respectively, as the temperature increases from 1100 °C to 1250 °C. At n(C)/n(Fe) lower than 0.8, most of the FeO·V2O3 and FeO·Cr2O3 are not reduced to carbides because of the lack of carbonaceous reductants, and the temperature has little effect on the reduction behaviors of FeO·V2O3 and FeO·Cr2O3, resulting in very low recoveries of vanadium and chromium during magnetic separation. However, at higher n(C)/n(Fe), the reduction rates of FeO·V2O3 and FeO·Cr2O3 increase significatly because of the excess amount of carbonaceous reductants. Moreover, higher temperatures largely induce the reduction of FeO·V2O3 and FeO·Cr2O3 to carbides. The newly formed carbides are then dissolved in the γ(FCC) phase, and recovered accompanied with the metallic iron during magnetic separation.

钒钛磁铁矿矿石基因特性及其对选铁的影响

钒钛磁铁矿属于晚期岩浆矿床,具有专属的矿石基因特性。通过对攀西钒钛磁铁矿矿石结构构造、矿物组成和矿物特征等矿石基因特性进行研究,发现格状结构在矿石中普遍存在,磁铁矿中的钛铁矿客晶呈微细片晶产出,片晶宽一般为20~0.1μm;磁铁矿中的铁普遍被钛、钒、铬、镁等元素取代;磁铁矿中FeO的含量低时仅为79.802%,而TiO_(2)含量高达10.437%。这些因素是影响矿石中铁、钛的回收率以及钒铁精矿中的含钛量和铁品位的根本原因。