烧结和球团添加含硼铁精矿的研究

在实验室条件下，进行了烧结和球团配加含硼铁精矿的试验研究。研究表明；配加含硼铁精矿能提高烧结矿、球团矿的强度和还原性，降低球团矿的焙烧温度，改善烧结矿的生产指标。含硼铁精矿在具备条件的情况下是炼铁工业的经济合理的新型添加剂。     

新型含硼添加剂初探

对含硼铁精矿作为球团含硼添加剂进行的探索性研究表明：含硼铁精矿是一种良好的球团含硼添加剂，性能优于硼泥。     

含硼铁精矿添加剂改善烧结矿质量的工业试验

 以含硼铁精矿作为烧结添加剂,在本钢炼铁厂生产条件下,研究了含硼铁精矿对烧结矿质量的影响。工业试验表明：含硼铁精矿是一种良好的烧结原料,烧结配加含硼铁精矿可提高烧结矿强度,降低烧结矿粉化率,改善烧结矿粒度组成和还原性,同时对烧结矿TFe含量无明显影响。     

球团矿加含硼添加剂的研究

从原料天然性质、成球性、球团矿的焙烧和冶金性能等方面研究含硼添加剂对球团过程及其产品质量的影响。结果表明,少量含B_2O_3添加剂可以有效地改善焙烧性差的铁精矿球团的固结。同时,球团矿冶金性质良好。但是,硼泥降低生球的破裂温度,可以通过选择合适工艺避免开裂对球团性质和生产过程的危害。对含硼添加剂的影响机理作了研究和解释。     

含硼铁矿球团矿生产工艺研究

给出了CCFHO生产含硼铁矿球团矿工业试验结果。结果表明,该工艺可使成品球团矿抗压强度提高18．5％,还原强度提高1倍,石灰石用量减少11％,膨润土用量缩减一半。可以推荐该工艺用于工业生产中。     

造块用含硼添加剂的使用研究现状和发展

本语文概述了国内使用含硼添加剂的发展现状，以及含硼添加剂研究的最新发展。提出含硼添加剂的使用可改善人造富矿的冶金性质，硼铁精矿将成为造块的首选含硼添加剂。     

硼对铬锰钼系含硼调质钢淬透性的影响

摘要：以实验室冶炼的铬锰钼系含硼调质钢为材料,通过末端淬火实验和微观组织分析,研究了硼元素对铬锰钼系含硼调质钢淬透性的影响。结果表明,硼元素对实验钢所表现的淬透性效果,仅在一定的区间（J11~J40）内作用明显,在这个区间内,淬透性随酸溶硼(Bsol)含量的增加而升高,且当Bsol质量分数为0.0012%左右,其淬透性最好。但是,如钢中添加了合金元素如V、Nb等,易形成含硼析出相,会降低酸溶硼中有效硼的占比,进而影响以Bsol含量来判断淬透性的准确性。研究结果可为含硼调质钢生产实践和新工艺的制定提供一定的参考依据。     

热能中子防护用含硼不锈钢

据 TEAN ISIJ 1988,No7报道在核燃料的再加工系统中,用含硼不锈钢作为贮运已消耗核燃料容器材料的需求正在增长,因为这些材料对热能中子具有极好的吸收性能,实际上硼不能溶于γ相,故过量添加硼会导致析出硼化物,从而使高温延展性大大降低。我们己对含硼奥氏体不锈钢的热加工作了广泛研究,找到了热轧最佳条件。基于     

鞍钢烧结配加含硼铁精矿工业生产实践

鞍钢烧结生产配加含硼铁精矿后,烧结矿自然粉化率降低,冶金性能指标改善;高炉使用含硼烧结矿冶炼,炉况顺行、焦比下降、产量提高.     

含硼高硅铁液中碳的氧化规律

以含硼生铁为原料直接冶炼硼钢新工艺的关键问题是硼、硅及碳的氧化规律.利用中频感应炉,刚玉坩埚盛装试样,研究了吹氧条件下,温度为(1 723士25)K时Fe-C-Si、Fe-C-B合金熔体及含硼高硅铁液中碳的氧化规律.结果表明:对于Fe-C-Si熔体,在熔炼开始的15 min内,主要是硅氧化,其氧化率达到88%.之后,碳和硅同时氧化,碳氧化呈线性规律,熔炼进行25 min时,碳的氧化率为44%;对于Fe-C-B合金熔体,硼与碳同时氧化,碳的氧化规律呈线性,但其氧化速率比硼慢得多.熔炼进行27 min时,硼的氧化率已达到96%,而碳的氧化率仅为22%;对于含硼高硅铁液,在熔炼进行的40 min之前,主要是硼和硅氧化,其氧化率分别达到94%和99%.之后,碳、硼、硅同时氧化,碳氧化呈线性规律,当熔炼进行到60 min时,碳的氧化率为93%.     

Mechanism of Strength Improvement of Magnetite Pellet by Adding Boron-bearing Iron Concentrate

The mechanism of improving compressive strength of magnetite pellet by adding boron-bearing iron concentrate was studied. Boron-bearing iron concentrate and magnetite were mixed, pelletized and roasted under differ ent roasting conditions. Then, compressive strength of pellets was tested, and polished sections of the roasted pellets were analyzed from the perspective of mineralogy. Finally, the effects of different proportions, roasting temperatures and roasting time of boron-bearing iron concentrate on the compressive strength of magnetite pellets were investigated and explained.     

硼铁精矿的碳热还原动力学

为了揭示硼铁精矿的碳热还原机理,以高纯石墨为还原剂,进行硼铁精矿含碳球团等温还原实验,并采用积分法进行动力学分析.还原温度分别设定为1000、1050、1100、1150、1200、1250和1300℃,配碳量即C/O摩尔比=1.0.当还原度为0.1<α<0.8时,温度对活化能和速率控制环节有重要影响:还原温度≤1100℃时,平均活化能为202.6 k J·mol-1,还原反应的速率控制环节为碳的气化反应;还原温度>1100℃时,平均活化能为116.7 k J·mol-1,为碳气化反应和Fe O还原反应共同控制.当还原度α≥0.8时(还原温度>1100℃),可能的速率控制环节为碳原子在金属铁中的扩散.碳气化反应是含碳球团还原过程中主要速率控制环节,原因在于硼铁精矿中硼元素对碳气化反应具有较强烈的化学抑制作用.      

Reduction of boron-bearing iron ore concentrate/coal composite pellet and kinetics analysis

Ludwigite is a complex iron ore containing boron and it is the most abundant boron resource in China. Boron-bearing iron ore concentrate is an intermediate product of the ore dressing process of crude low-grade ludwigite and extracting boron from it has great influence on the total boron yield. Pre-reduction of the boron-bearing iron ore concentrate is one of the important steps of the pyrometallurgical boron and iron separation process. In the present work, non-isothermal and isothermal reduction of boron-bearing iron ore concentrate/coal composite pellet was performed. The evolution of reaction fraction, carbon consumption, off-gas evolution, phase composition and microstructure were systematically revealed based on reduction experimental results in conjunction with X-ray diffraction, scanning electron microscope-energy dispersive spectrometer and electron probe micro analyzer analysis. The kinetics of the reduction of the composite pellet was also analysed. The reduction mechanism changed at a temperature around 1150°C. The rate of carbon gasification in the composite pellet during the reduction decreased mainly due to the chemical inhibition by B₂O₃ on the electron transfer.     

Influence of Na2 CO3 as Additive on Direct Reduction of Boron-bearing Magnetite Concentrate

Boron-bearing magnetite concentrate is typically characterized by low grade of iron and boron (wTFe=51%-54%,wB2 O3=6%-8%),as well as the close intergrowth of ascharite phase and magnetite phase.A promising technology was proposed to separate iron and boron by coupling the direct reduction of iron oxides and Na activation of boron minerals together.The influence of Na2 CO3 as additive on the direct reduction of boron-bearing magnetite was studied by chemical analysis,kinetic analysis,XRD analysis and SEM analysis.The results showed that the ad-dition of Na2 CO3 not only activated boron minerals,but also reduced the activation energy of the reaction and pro-moted the reduction of iron oxides.Besides,the addition of Na2 CO3 changed the composition and melting point of non-ferrous phase,and then promoted the growth and aggregation of iron grains,which was conducive to the subse-quent magnetic separation.Thus,the coupling of the two processes is advantageous.     

Effect of heating pretreatment on ballability of hematite concentrate with flotation process

The experiments were carried out to investigate the mechanism of lower cracking temperature of green pellet made by iron concentrate with flotation process. The results of Fourier transform infrared spectroscopy??FTIR?? analysis indicate that the iron concentrate of green pellet with lowest cracking temperature has the strongest sodium oleate transmittance of infrared spectrum. When the iron concentrate is heated to 70, 150 and 250??, respectively, the sodium oleate transmittance weakens and the cracking temperature of green pellet increases observably. The sodium oleate that attached to the surface of iron concentrate make the iron concentrate more hydrophobic, which leads to faster vaporizing speed of pellets moisture and lower cracking temperature of green pellet. The pretreatment of heating iron concentrate above 150?? can effectively decrease the residual sodium oleate on the surface of iron concentrate and improve the cracking temperature of green pellet.     

调军台精矿用于球团生产的实验研究

摘要,在鞍钢原料条件下,采用正交设计的方法进行了球团生产配加调军台精矿的实验室研究,给出配加调军台精矿后生球团生产的合理工艺参数,并在此基础上进行配加调军台精矿的球团投笼中间试验.实验结果表明,球团车间铁料最佳配比为:调军台精矿∶X精矿=60∶40.     

武钢金山店高品位球团矿制备研究

对金山店铁矿弱磁精矿用武科大自行设计的磁聚机进行磁团素重选，精矿品位可以提高到68．15％。只配用常规的膨润土粘结剂便可得到铁品位高于65％的氧化球团矿；若配合使用武科大研制的WKD型粘结剂，铁品位提高更多，达到67．41％。     

低铁高硅赤铁精矿对氧化球团性能的影响

为合理利用国内低铁高硅铁精矿、降低球团生产成本,研究了低铁高硅赤铁精矿对生球、预热球和焙烧球团性能的影响。结果表明,典型的低铁高硅赤铁精矿A较磁铁精矿有更好的润磨性能。赤铁精矿A的亲水性较磁铁精矿强,在保持生球水分不变且赤铁精矿配比较高的条件下(>10%),生球水分不足,生球质量随着赤铁矿配比的提高而变差。随着赤铁精矿A的配比由0提高到50%,预热球强度由588降低到196 N/个,焙烧球团抗压强度由3 425降低到1 368 N/个,赤铁精矿A配比不宜高于30%,适当提高焙烧温度有利于球团抗压强度的提高。配加低铁高硅赤铁精矿A的球团还原膨胀性能和还原性能均有一定程度改善。     

含镍、铬复合氧化球团的制备工艺

 利用廉价的低品位铬铁矿精矿以及红土镍矿制备含镍、铬复合球团,用于高炉生产含镍和铬不锈钢母液,对于保障不锈钢产业的可持续发展具有重要意义。系统研究含镍、铬球团制备工艺,探究红土镍矿配比、铬铁矿配比以及添加剂对球团强度的影响。结果表明,当混合料配比为45%红土镍矿+15%铬铁矿+40%铁精矿时,添加7.7%添加剂的混合料经高压辊磨预处理后可制备出合格生球,在预热1 000 ℃+12 min,焙烧(1 220～1 250 ℃)+12 min的条件下可获得抗压强度大于2 500N/个的成品球团,可用于高炉生产铁、镍和铬三元不锈钢母液。