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为了解决铬镍生铁因磷质量分数高用做不锈钢原料受限的问题,开展了关于含铬镍铁水脱磷保铬的理论计算和工业试验研究。采用竖炉工艺回收不锈钢粉尘,冶炼出的含铬镍铁水磷质量分数高,导致铁水利用量受限。通过计算铬、镍、铁氧化物还原热力学条件和磷、铬、碳氧化的临界氧势,提出了采用碱性CaO渣系、控制炉渣氧势和出铁温度实现脱磷保铬的措施。在理论计算基础上,进行了竖炉冶炼含铬镍铁水的脱磷保铬工业试验。试验共冶炼出含铬镍铁水32 t,当炉渣碱度为1.15、炉渣[w(FeO)]为4.98%、出铁温度为1 673~1 684 K时,脱磷率可达36%以上,铁水中磷质量分数可降至0.023%,铬收得率为88%以上,本研究达到了脱磷保铬的目的,并且解决了含铬镍铁水磷质量分数高的问题。 相似文献
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在实验室利用转炉渣配制的铁水脱磷剂进行铁水预脱磷试验,测定了脱磷剂组成等因素对脱磷率的影响。结果表明:在铁水脱磷前[Si]≤0.15%条件下,当脱磷剂中转炉渣配比为80%时,相应铁水脱磷率约为78%;Fe2O3和BaCO3代替转炉渣的合适替代量分别约为5%和10%;脱磷剂中(P2O5)含量的增加会导致脱磷率的显著降低,其影响关系式为:ηp(%)=84.01—4.60(P2O5%)。 相似文献
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为开发高效环保的高磷铁水预脱磷剂,利用FactsageTM软件绘制了Fe3O4-CaO-B2O3和Fe3O4-CaO-K2O三元相图,根据相图确定出B2O3系和K2O系脱磷剂成分的质量分数,然后在实验室进行脱磷试验,并与以CaF2为助熔剂的高磷铁水预脱磷试验结果进行了比较。结果表明:B2O3能够完全替代CaF2作为助熔剂进行高磷铁水的脱磷预处理,控制w(P)<0.1%,此时w(B2O3)/w(CaO)=0.16,用此种脱磷剂进行脱磷时,化渣良好且不产生泡沫渣,脱磷率也最高。而K2O系脱磷剂的脱磷效果较差。 相似文献
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实验室条件下采用间接测量法,测定了CaF2系和B2O3系脱磷渣的磷分配.即首先测量磷在液态渣和固态铁间的分配比,再通过计算得到磷在液态渣和铁水之间分配比,同时根据渣系成分和光学碱度计算了磷容量.同时采用了扫描电镜、能谱分析与X射线衍射分析技术对脱磷渣进行了研究.实验结果表明,B2O3系预脱磷渣的磷容量远大于CaF2系预脱磷渣的磷容量,因此可以用B2O3全部替代CaF2作为助熔剂进行高磷铁水的预脱磷处理,2种渣系的磷分配均随渣中有效CaO含量的升高而升高.用B2O3作为助熔剂时,B2O3能与渣中高熔点物质2CaO·SiO2和3CaO·P2O5反应生成低熔点物质,从而起到助熔的作用.且w(B2O3)/w(CaO)比值为0.16时,磷分配比为最高值,即该渣脱磷能力最强. 相似文献
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高磷铁水预处理脱磷的难题是脱磷剂用量太大、温降太多,急需研究脱磷能力强的脱磷剂。含有固体颗粒和液渣的非均相脱磷剂比仅含液渣的均相脱磷剂的脱磷能力强很多。为此,针对磷的质量分数为0.5%的高磷铁水,应用FactSageTM热力学软件优选出脱磷能力强的3种液渣,添加不同数量的硅酸二钙颗粒配制非均相脱磷剂试样,脱磷剂和熔铁在1 560℃下反应6h,测定熔铁中的平衡磷含量,用以评价其脱磷能力,然后在1 400℃下进行了铁水脱磷预处理试验。研究结果表明,随着硅酸二钙颗粒含量的增加,非均相脱磷剂的脱磷能力明显改善;采用非均相脱磷剂有助于减少渣量和控制反应器内衬的侵蚀;采用非均相脱磷剂对铁水脱磷,仍然需要控制较高的渣铁界面FetO浓度。 相似文献
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白云鄂博铁精矿磷含量较高为0.08%(质量分数),且磷元素主要以氟磷灰石的形式存在。基于前期白云鄂博矿磷的赋存状态及白云鄂博矿预还原烧结工艺对脱磷影响的研究,同时为了开发利用其他中、高磷铁矿,研究了白云鄂博铁精矿预还原烧结过程中磷的气化脱除机制。利用FactSage热力学软件、XRD、SEM-EDS对比分析不同SiO2、Na2CO3添加量对预还原烧结过程中气化脱磷率、金属化率以及物相转变的影响。结果表明:最佳的SiO2、Na2CO3添加量(质量分数)分别为3%、1%,对应的脱磷率为31%,金属化率为96%,实现了预还原烧结过程中磷的有效脱除,进一步明确预还原烧结脱磷机制,为以后中、高磷铁矿脱磷的研究指明了方向。 相似文献
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《钢铁研究学报(英文版)》2016,(7):661-668
High pressure roll grinding (HPRG)and ball milling were compared to investigate the influence of me-chanical activation on the acid leaching dephosphorization of a high-phosphorus iron ore concentrate,which was man-ufactured through magnetizing roasting-magnetic separation of high-phosphorus oolitic iron ores.The results indica-ted that when high-phosphorus iron ore concentrates containing 54·92 mass% iron and 0·76 mass% phosphorus were directly processed through acid leaching,iron ore concentrates containing 55·74 mass% iron and 0·33 mass%phosphorus with an iron recovery of 84·64% and dephosphorization of 63·79% were obtained.When high-phosphor-us iron ore concentrates activated by ball milling were processed by acid leaching,iron ore concentrates containing 56·03 mass% iron and 0·21 mass% phosphorus with an iron recovery of 85·65% and dephosphorization of 77·49%were obtained.Meanwhile,when high-phosphorus iron ore concentrates activated by HPRG were processed by acid leaching,iron ore concentrates containing 58·02 mass% iron and 0·10 mass% phosphorus were obtained,with the iron recovery reaching 88·42% and the dephosphorization rate reaching 88·99%.Mechanistic studies demonstrated that ball milling can reduce the particle size,demonstrating a prominent reunion phenomenon.In contrast,HPRG pretreatment contributes to the formation of more cracks within the particles and selective dissociation of iron and P bearing minerals,which can provide the favorable kinetic conditions to accelerate the solid-liquid reaction rate.As such,the crystal structure is destroyed and the surface energy of mineral particles is strengthened by mechanical ac-tivation,further strengthening the dephosphorization. 相似文献
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在填有铁矿石的反应器内加入添加剂,对模拟烟气进行脱除NOx的研究。结果表明:随着温度的升高、矿石粒度减小、料层高度增加,NOx的脱除率增加。铁矿石对脱除NOx有催化作用,钒钛磁铁矿中TiO2和V2O5的含量较高,催化能力最强,NO的脱除率接近100%。通过烧结杯实验研究了工艺条件对脱氮的影响。研究发现,添加剂分解产生的NH3在烧结过程中会发生氧化反应生成NO,烧结温度过高会加剧氧化反应的进行,因此选择合适的添加剂配比及配碳量在实际生产中显得十分重要。烧结矿碱度的提高有利于脱氮。 相似文献
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In order to examine the possibility of recycling BOF slags as dephosphorization and desulphurization fluxes, experiments were performed in a system with liquid iron and artificially prepared fluxes comprising BOF slags, lime and/or sinter ore in a Al2O3 crucible at 1623 and 1673K. The phosphorus and sulphur content in liquid iron were expressed as a function of reaction time in the form of exponential decay of first order. CaF2‐free fluxes comprising BOF slags, lime and/or sinter ore showed very high capacities of dephosphorization and desulphurization, which means that BOF slags could largely be recycled in the hot metal pretreatment processes. 相似文献
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《钢铁研究学报(英文版)》2014
The Bayan Obo iron ore contains valuable metallic elements such as niobium and rare earth elements. However, developing appropriate metallurgical processes to achieve effective dephosphorization of Nb-bearing hot metal meanwhile retaining Nb in the steel products remains a challenge. We carried out a thermodynamic study on dephosphorization of Nb bearing hot metal and investigated the effects of the initial [C] content and the dephosphorization temperature on oxidation behaviors of [Nb] and [P]. In particular, we focused on thermodynamic analysis of dephosphorization of Nb-bearing hot metal with highly basic BaO-based slag. The results showed that the highly basic BaO-based slag system is more suitable for dephosphorization under oxidative conditions, and increasing the [C] content favors dephosphorization of Nb-bearing hot metal without oxidizing [Nb]. Moreover, the values of equilibrium oxygen activity for oxidation reactions of [Nb] and [P] are increased as the dephosphorization temperature increases. Considering the hot metal containing 0.02% of [Nb] in Baotou Steel, thermodynamic calculations indicated that the content of [P] can be reduced to 0.02%–0.05% and [Nb] remains unoxidized when dephosphorization occurs at the cconditions of T=1573–1673 K, [C]=4.0%, [Nb]=0.02%, aP2O5 =10−24, aNb2O5 =10−10. 相似文献
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In order to examine the possibility of utilizing Mn ore in the pretreatment process of liquid iron, experiments were carried out in a system with liquid iron and CaO‐SiO2‐MgO‐Al2O3‐FeO slag with additives (Mn ore and Fe2O3+MnO2) in a magnesia crucible at 1673K. When Mn ore was added to the pretreatment slag, decarburization, desiliconization, dephosphorization and desulphurization proceeded simultaneously with the reduction of Mn ore. The reduction rate of MnO and the Mn concentration in the melt increased with increasing initial Si content. The maximum dephosphorization was obtained when the additive consisted of 66.6 mass% Fe2O3 and 33.4 mass% MnO2. The desulphurization ratio increased with increasing the relative amount of MnO2 in the additives. The amount of additives comprising Fe2O3 and MnO2 required for a targeted manganese content could be predicted using the mass balance. Effects of the additives on dephosphorization were also estimated. 相似文献