钒在FeO-SiO_2-MnO渣系与铁液间的分配行为

在实验室条件下,系统研究了1380℃下,钒在FeO-SiO2-MnO渣系与铁液间的分配行为。结果表明:钒的提取率、钒在渣-金两相的分配比、渣的钒容量随渣中SiO2的质量分数升高而降低。在SiO2的质量分数较低时,以上参数随MnO质量分数的增加而升高。而在SiO2的质量分数较高(>20%)时,随MnO质量分数的增加呈现先升高后降低的趋势。FeO-SiO2-MnO三元渣系中,SiO2的质量分数为10%~20%、MnO的质量分数为13%~5%时,以上参数达到最大值,且该区域对应着FeO-SiO2-MnO渣系熔点最低的区域。V2O3在FeO-SiO2-MnO渣系中活度系数的数量级为10-6~10-7。     

钒在铁液和转炉渣间分配的热力学研究

通过热力学试验研究的方法研究了1600℃时含钒铁液与含钒转炉渣系CaO-MgOsat-FetO-MnO-SiO2-V2O5-TiO2-Al2O3间钒的分配平衡.X射线衍射分析发现,在碱度较高的转炉渣中,钒以五价态的形式存在.计算了钒在铁/渣间的平衡分配比Lv和渣中V2O5的活度系数γv2o5,考察了渣中FetO、V2O5含量和炉渣碱度对Lv和γC2O5的影响.测定结果表明,含钒转炉钢渣的γv2o5值在10-10左右.从试验结果建立了γv2o5的计算模型.     

CaO—MgOsat—FeOn—SiO2渣系与铁液间磷平衡分配比的极值模型探讨

本文基于实验结果和生产实践,借助多元逐步回归分析等方法,得出了不同碱度区域内反映的Lp极值模型:揭示了Lp与(ΣFeo)或(TFe)之间的极值关系存在下述规律:(1)有一个与Lp最大值对应存在的极值特征准数和(ΣFeO)最佳值;(2)定义该特征准数的变量应根据渣系的特征而定,如本渣系取[(％CaO)+0.7(％MgO)]/(％TFe),CFS渣系取(％CaO)/(％TFe);(3)其特征准数值随渣系或碱度范围不同而不同,在一定的碱度范围内则为定值,并在 Cao/ SiO_2=0.9～1.9,[(％CaO)+0.7(％MgO)/(％TFe)准数值最大,以及在CaO/SiO_2=0.91～1.4范围,(ΣFeO)最佳值最小.可以期望本文提出的Lp极大值模型和极值特征准数对优化炼钢的脱磷工艺具有重要的理论和经济意义。     

吹炼终点钒在渣铁间的分配比及相分析

采用具备顶底复吹功能的500 kg中频感应炉模拟复吹转炉铁水提钒工艺,研究吹炼终点钒在渣铁间的分配比;运用X射线衍射分析钒铁尖晶石的分子组成。试验结果表明:吹炼终点钒在渣铁间分配比Lv为1.8~2.8,且与渣中FeO含量相关。为了保证钒渣质量,降低钒渣中FeO含量,减少铁损,吹炼终点V的质量分数不宜过低。钒渣中钒铁尖晶石的分子式为FeO(Fe,V)_2O_3,表明钒渣中钒为+3价。吹炼初期钒渣中存在少量+2价钒,随着供氧量增加,+2价钒的数量逐渐减少。     

转炉提钒终点钒的分配行为

运用共存理论建立了钒渣活度计算模型,分析了钒渣成分和温度对渣中FeO、V₂O₃活度及活度系数的影响;通过实验和理论计算,分析了转炉提钒终点钒渣成分和温度对钒在渣和半钢间分配行为的影响.结果表明,渣中FeO的活度和活度系数随MnO和FeO含量的增加而增加,随V₂O₃、SiO₂和TiO₂含量的增加而减小,其值分别在10-1和100的数量级上,而渣中V₂O₃的活度及活度系数在同样条件下的变化与FeO相反,其值分别在10-2和10-1的数量级上;半钢V的质量分数一般在0.02%~0.06%之间,随温度以及渣中V₂O₃、TiO₂和SiO₂含量升高而升高,随FeO含量降低而升高;V在渣金间的分配比为100~500,随温度和渣中TiO₂、SiO₂含量升高而降低,随FeO含量升高而升高;存在一个临界V₂O₃含量使得V在渣金间的分配比达到最大,该值的理论计算结果为23.77%,实验结果在15%~20%.     

提钒弃渣回用对钒渣焙烧的影响

以钒渣和弃渣为原料,碳酸钠和氯化钠为钠化剂,进行焙烧试验。不仅降低钒资源的损失,而且能减轻环境污染。通过硫酸亚铁铵滴定法,考察了焙烧温度、保温时间、碱比、碱盐比对不同钒含量样品钒浸出率的影响。结果表明:钒渣中适量的弃渣加入能促进钒转化率的提高;弃渣掺杂量16.376%时,最佳煅烧温度为800℃,保温时间为60 min,碱比1.5,碱盐比3.5,钒浸出率98.43%。     

Effects of Influencing Factors on Distribution Behaviors of Vanadium between Hot Metal and FeO‐SiO2‐MnO (‐TiO2) Slag System

The distribution behavior of vanadium between a hot metal and a FeO‐SiO₂‐MnO (‐TiO₂) slag system was studied under laboratory conditions, together with the effects of influencing factors such as temperature, slag composition, the ratio of slag to hot metal, and the initial Si and/or Ti content in hot metal. The results suggested that in a ternary FeO‐SiO₂‐MnO slag system, with an increase in temperature and an increase in the SiO₂ content of slag, the extraction ratio ($\eta _{V} $ ), distribution ratio of V ($L_{V} $ ) and the vanadium capacity of the slag ($C_{VO_{3} {}^{3{-} } } $ ) decreased, while the effect of MnO content in slag showed a different tendency under different situations. For both high and low ratios of slag to hot metal, the extraction ratio of V reached its maximum value under slag compositions of 13%–25% MnO and 10%–24% SiO₂, which correspond to the regions with lower melting point and lower viscosity of the slag. In a quaternary FeO‐SiO₂‐MnO‐TiO₂ slag system,$\eta _{V} $ ,$L_{V} $ , and $C_{VO_{3} {}^{3{-} } } $ decreased, while the activity coefficient of V₂O₃ increased, as the TiO₂ content increased. Further, the data suggested that under laboratory conditions the effects of influencing factors on the extraction ratio of V from hot metal decreased in the following order: final slag composition > temperature > initial Si and/or Ti content in hot metal.     

含钒转炉钢渣中钒的提取与回收

针对攀钢目前含钒铁水的工艺流程和含钒转炉钢渣中V2O3含量,提出了从含钒钢渣提钒的新的技术思路和工艺,并对新工艺的关键环节——含钒钢渣冶炼和高钒铁水提钒进行了试验研究。结果表明：采用矿热炉冶炼含钒钢渣,生铁中钒的质量分数达7．45％,对含钒生铁进行提钒,钒渣中V2O3;的质量分数达35．06％,实现了钒资源的有效提取和综合回收。     

A Study of Some Elemental Distributions Between Slag and Hot Metal During Tapping of the Blast Furnace

This paper investigates the distribution of elements between slag and hot metal from a blast furnace through calculation of distribution coefficients from actual production data. First, samples of slag and hot metal tapped from a commercial blast furnace were taken continually at 10‐minute intervals for a production period of 68 hours. Distribution coefficients of manganese, silicon, sulphur and vanadium were then calculated from the results of the sample analyses. A major conclusion drawn from examination of the results was that the behaviour of the studied elements was as could be expected when approaching the equilibrium reactions from thermodynamic theory. The distributions of the elements in the slag‐metal system showed clear tendencies which did not appear to be influenced by the operational conditions of the furnace. For example, for manganese, vanadium and sulphur, it was found that a higher basicity led to a decreased distribution coefficient L_Mn and L_V, but an increased L_S, which is according to theory. Another observed relationship was that slag basicity increased with an increased carbon content in the hot metal, which indicated that SiO₂ was reduced to [Si] when the oxygen potential decreased. Furthermore, it was found that sulphur and silica behaviour likened that of acidic slag components, while the manganese oxide and vanadium oxide behaviour was similar to that of basic slag components.     

承钢含钒铁水预脱硫处理工艺优化

承钢含钒铁水在单喷镁脱硫预处理时,脱硫渣较稀,不宜扒除,易回硫,针对其特殊的铁水条件,结合生产实践,通过对主吹流量和给料速度进行优化,平均脱硫率提高了12.38%,堵枪现象得到有效减少;通过在出铁前预先加入适量的钙基脱硫剂,钝化镁利用率提高了8.66%,脱硫渣况得到改善,扒渣效果增强,平均回硫减少0.006%,并且不会影响钒渣质量。     

亚熔盐法钒渣高效清洁提钒技术

针对目前钒渣焙烧提钒工艺钒资源利用率低、铬无法同步提取、"三废"环境污染严重等问题,基于亚熔盐非常规介质优异的物理化学性能,通过反应分离耦合工艺设计,提出了亚熔盐法高效清洁提钒新技术。亚熔盐新技术可将钒渣分解温度由传统工艺的850℃降至200～400℃,钒一次转化率可达95%以上,铬回收率提高到80%以上,可望突破传统钒渣提钒方法的资源环境制约。     

钒渣冷却方式对钒尖晶石颗粒大小及钠化焙烧效果的影响

对三种不同冷却方式得到的水冷钒渣、风冷钒渣和缓冷钒渣的物相结构、钒尖晶石颗粒大小进行了分析,考察了氮气气氛下1 000℃保温时间对钒尖晶石颗粒大小的影响,并对水冷钒渣、风冷钒渣和缓冷钒渣在相同条件下的钠化焙烧效果进行了比较。研究结果表明,缓冷和1 000℃保温有利于钒尖晶石颗粒长大;-0.125 mm钒渣在不添加提钒尾渣焙烧时,不同粒度范围的水冷钒渣焙烧钒转化率比同粒度范围的缓冷钒渣低1～2个百分点;-0.125 mm钒渣添加提钒尾渣焙烧时,水冷钒渣焙烧钒转化率比缓冷钒渣低0.56个百分点。     

攀钢转炉钒渣钠化焙烧实验室研究

在实验室条件下,研究了转炉钒渣在焙烧过程中的碱比、返渣比、焙烧温度、焙烧时间等对钒转浸率的影响。试验结果表明,控制碱比为3.4,返渣比为2∶3,焙烧温度820℃,焙烧时间120 min,可以使钒转浸率达到90%,残渣中的TV含量达到0.6%左右,浸出液澄清透明。