转炉渣用于铁水预脱磷的工艺实验

 研究了转炉渣剂的组成及相关工艺因素对铁水脱磷率的影响。结果表明：为降低转炉渣的熔化温度以适应铁水预处理温度的要求，转炉渣的CaF2添加量应控制在15%~20%；采用80%的转炉渣和20%的CaF2配制的转炉渣剂对铁水进行脱磷处理时，脱磷率可达到78%左右；另外，转炉渣剂中的P2O5能显著降低铁水脱磷率。     

用预熔渣对铁水脱磷的试验研究

以铁水和脱磷粉剂为研究体系,应用CaO-Fe2O3-CaF2渣系的脱磷粉剂和其预熔渣对铁水脱磷,研究结果表明,用Al2O3和白云石部分替代萤石,预熔后的脱磷渣都比未预熔渣的脱磷速度快,且二者的处理过程结果基本相似,脱磷粉剂经过预熔处理,成渣迅速,预处理时间缩短,温降小,脱磷率高。     

转炉渣用于铁水脱磷的试验研究

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％）。     

利用转炉渣对铁水脱磷的动力学

在实验室条件下，模拟转炉渣组成，利用CaO-SiQ-Fe2O3-MnO2-MgO-P2O5-Al2O3-CaF2系熔剂对铁水进行脱磷预处理。实验发现：随着预处理时间的延长，铁水发生回磷反应。在铁水回磷状态下，测定了磷在渣中的传质系数。讨论了回磷原因和抑制铁水回磷反应的措施。在此基础上，确定了合适的铁水脱磷预处理时间和转炉渣的优化组成。     

液渣成分和硅酸二钙颗粒含量对铁水预处理非均相脱磷剂脱磷能力的影响简

 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1560℃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1400℃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。     

铁水包脱磷工艺研究

研究在铁水包内喷吹CaO粉剂、顶加氧化铁皮及同时喷吹氧气的铁水脱磷反应。通过测定实际生产过程中脱磷渣的磷平衡分配比及其它组成物成份和相关工艺参数,计算出脱磷渣的磷容量,进而分析了铁水硅含量、温度、脱磷渣碱度及氧化铁等成份对该脱磷工艺的影响。     

返回转炉钢渣对铁水脱硅、脱磷的影响

在实验室条件下，模拟转炉钢渣的组成，利用CaO-SiO2-Fe2O3-MnO2-MgO-P2O5-Al2O3-CaF2系熔剂对铁水进行预处理，研究了转炉钢渣组成和渣中添加BaO对铁水脱硅和脱磷的影响。结果表明，通过控制转炉钢渣的组成可获得约75％的脱硅率和80％左右的脱磷率。脱硅过程伴随有铁水的回磷反应。随Fe2O3含量增加，回磷率提高，最大回磷率可达22．5％。此外，分析了铁水回磷原因和防止回磷的，发现使用添加BaO的转炉钢渣对脱硅后的铁水进行脱磷处理，当BaO添加量控制在15％－20％范围内时，可明显提高铁水的脱磷率。     

Study on Kinetic Model for Dephosphorization of High-Phosphorus Hot Metal Pretreatment

Focused on the hot metal pretreatment process in the torpedo-car and based on the powder injection metallurgy principle, a kinetic model for dephosphorization of high-phosphorus hot metal pretreatment was developed. The validity of this model was verified by comparison between the experimental results in laboratory and the calculated results. The influences of dephosphorization capacity of molten slag and technological conditions on the dephosphorization efficiency were calculated by applying the model. The results show that lower temperatures are favorable to dephosphorization, CaO content in slag should be controlled at about 50%, suitable initial phosphorus content in the hot metal with higher phosphorus contents is about 0.35% by comprehensively considering various factors, slag systems of higher iron oxide content and higher basicity have higher capacity of dephosphorization.     

Vacuum Treatment for Simultaneous Desulphurization and Dephosphorization of Hot Metal and Molten Steel

The vacuum treatment for simultaneous desulphurization and dephosphorization of hot metal and molten steel with pre-melted CaO-based slag was carried out. For pre-treatment of hot metal, both desulphurization and dephosphorization are improved with the increase of CaO in slag, but deteriorated with the increase of CaF2 in slag. The average desulphurization and dephosphorization rate is 68.83% and 78.46 %, respectively. For molten steel, the sub-stitution of BaO for CaO in slag has minor effect on simultaneous desulphurization and dephosphorization. The desulphurization and dephosphorization rate is higher than 90 % and 50% respectively with the lowest final sulfur and phosphorus mass percent being 0. 001 2 % and 0. 010%, respectively. The overall effect of simultaneous desulphurization and dephosphorization of molten steel is better than that of hot metal.     

低碱度渣铁水预处理脱磷研究

低碱度渣铁水预处理脱磷的一个主要特点是形成高氧势、低碱度炉渣.实验选用炉渣碱度1.3～1.8,(ω)(TFe)为20%～25%,底搅强度大于0.20 m3/(min·t),对4.0%(ω)(C)-(0.1%～0.3%)(ω)(P)-0.4%(ω)(Si)的铁水进行铁水脱磷预处理.实验表明,低碱度渣能稳定获得200左右的脱磷分配比,脱磷率大于90%.同时对供氧参数和底吹强度对低碱度渣脱磷的影响进行了相应的讨论.     

苏打脱磷剂冲罐法铁水脱磷

 为研究铁水冲罐法对铁水预处理脱磷效果的影响,向放有一定量苏打的铁水罐中倒入铁水进行铁水脱磷工业试验研究。考察了铁水中Si、Ti浓度、铁水温度以及苏打添加量对脱磷率的影响,并比较了钙系脱磷剂与苏打的脱磷效果。结果表明：铁水中低的硅、钛浓度、低温以及适当的苏打消耗量有助于脱磷;与钙系脱磷剂只有一定的脱磷能力相比,苏打有较强的脱磷和脱硫能力;同时考察了氧气对苏打脱磷效果的影响,向铁水表面喷吹氧气可以减少铁水温降,为铁水的二次预处理提供温降空间,采用苏打铁水二次脱磷后,得到了w［P］＜0.010%的铁水;还考察了苏打脱磷过程中w［Cr］、w［V］和w［C］的变化,铁水中铬浓度几乎不变,钒几乎全部被氧化进入渣中,而碳浓度大约减小了0.2%(质量分数,下同)。     

转炉渣中氧化磷对铁水脱磷影响的研究

以转炉渣为基础渣,在实验室测定了CaF2、P2O5质量分数变化对转炉渣熔点的影响。依据测定结果,利用转炉渣配制适合铁水脱磷要求的脱磷剂进行了铁水预脱磷实验,结合相关的转炉脱磷研究结果,分析了脱磷剂中P2O5对脱磷的影响,提出了对最终外排炉渣中的质量分数要求。在1350 ℃温度条件下,w（P2O5）＝166％转炉渣为基础的脱磷剂,对预脱硅处理后的铁水,脱磷剂加入10％时可取得约77％的脱磷率。脱磷剂中w（P2O5）＜75％时可取得60％以上的脱磷率。     

含转炉渣的预熔脱磷剂进行铁水脱磷实验

在实验室条件下,用部分转炉渣代替预熔脱磷剂中纯化学试剂原料进行铁水预处理脱磷实验研究,研究发现,含有转炉渣的预熔脱磷剂能实现较好的脱磷效果;在1350℃,加入量为10％的条件下,含转炉渣45.73％的预熔脱磷剂能将铁水中的磷由0.21％降低到0.011％,脱磷率可达到94.76％。     

Thermodynamic Study on BaO－BaF_2－Fe_xO Slags Used for Dephosphorization of Chromium－Containing Hot Metal

ＴｈｅｒｍｏｄｙｎａｍｉｃＳｔｕｄｙｏｎＢａＯ－ＢａＦ_２－Ｆｅ_ｘＯＳｌａｇｓＵｓｅｄｆｏｒＤｅｐｈｏｓｐｈｏｒｉｚａｔｉｏｎｏｆＣｈｒｏｍｉｕｍ－ＣｏｎｔａｉｎｉｎｇＨｏｔＭｅｔａｌＣｈｅｎＺａｏｐｉｎｇ；ＪｉａｎｇＭａｏｆａ；ＬｉＹｉｎｔａｉＡｂ...     

Effect of Modification Treatment for Reduction of Dephosphorization Slag in Hot Metal Bath

To extract the valuable elements from the steel slag, a novel approach has been proposed by modification treatment to provide the stronger driving forces and accelerate the reduction. Three types of dephosphorization steel slags were reduced using carbon-saturated iron bath to extract iron and phosphorus simultaneously. During the process of reduction, slag composition, temperature, and original P2O5 content were investigated respectively. Slag modification treatment, adding either silica or alumina to vary the slag composition, was proven to accelerate the reduction of dephosphorization slag. The equilibrium time can be shortened from 60 to 30 min. Slag modification also allowed the reduction reaction to occur at lower temperature. After slag modification, the original P2O5 content in slag presents a slight difference on reduction process. Almost half of the reduced phosphorus was vaporized within 5 and 20 min. As more and more FeO was reduced, CO gas generation decreased, and evaporation amount of phosphorus therefore decreases.     

铁水脱磷技术的发展概况

叙述了铁水罐，混铁车，转炉铁水脱磷技术的发展概况及应用实绩，对脱磷工艺方案的选择提出了初步意见。     

高热装铁水比冶炼工艺的优化

 针对电弧炉炼钢过程中石灰消耗较高、炉渣中FeO含量过高的问题,研究了温度、炉渣成分、渣量、流渣时机对脱磷的影响以及终点碳含量、炉渣的碱度、吹氧强度对终点渣中FeO含量的影响,并对吹氧制度、造渣制度进行了优化。工业应用表明：石灰的消耗从每吨铁34. 3kg降到25. 2kg,氧气的消耗从每吨铁48. 2m3降到42. 5m3,终渣中w(FeO)从33. 4%降到25. 1%,终点w［C］从0. 07%提高到0. 15%。     

Thermodynamic Behaviors of Nb and P in Dephosphorization of Niobium-bearing Hot Metal with BaO-based Slag

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%, a_P2O5 =10⁻²⁴, a_Nb2O5 =10⁻¹⁰.     

大型转炉低硅铁水炼钢研究

针对转炉低硅铁水炼钢成渣困难,渣量少不利于脱磷,容易产生粘枪、粘烟罩等问题,在吹炼过程中加入适量熔剂,枪位稍高于正常含硅铁水炼钢,设计化渣效果好、喷溅少的多孔喷头。低硅铁水炼钢化学热减少,可减少矿石、废钢用量,保证熔池金属正常的升温速度。低硅铁水炼钢可以实现少渣炼钢,有利于减少石灰消耗和提高金属收得率。