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针对碳热还原工艺的特点,选择了以氟碳铈精矿燃烧矿、还原碳粉和粘结剂为原料,冷压内配碳稀土放造块工艺。以内配碳稀土精矿团块为对象,研究了不同告愉条件下团块的强度性能,讨论了矿粉粒度对团块强度的影响,成功地用于指导工业生产。测定了团块的密度、孔渡和抗爆性,并简略 地描述了团块的内部结构 相似文献
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《炼铁》1984,(1)
我厂长期以来一直是使用自熔性烧结矿单一的炉料结构,在高炉冶炼方面曾经获得较好的效果.但是,自熔性烧结矿强度差、粉末多、粒度不均匀、氧化亚铁高和高温性能差,致使进一步降低焦比和提高产量受到影响.由实验室和工业性试验表明,熔剂性烧结矿却具有良好的冶金性能. 1982年11月5日至30日在两座高炉上同时进行了高碱度烧结矿加硅石的新炉料结构工业性试验,在试验过程中使用碱度1.60~1.70的烧结矿,其冶金性能有了较大的提高,转鼓指数提高3~5%,氧化亚铁降低3.40%,还原率提高8%,低温还原粉化率降低5%,软化温度提高40℃,并且粒度均匀.在冶炼铸造生铁比重占66%的情况下, 相似文献
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分析了在锰硅电炉冶炼过程中影响SiO2还原的因素.当SiO2的还原率高,混合锰矿中SiO2含量适当时,可以实现不加硅石冶炼锰硅合金.在设定Si回收率条件下,对混合锰矿中应含SiO2的量进行了计算,并介绍了冶炼锰硅不加硅石的生产实践. 相似文献
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采用便宜的煤碳热预还原在改善铬铁生产的成本效益中极为重要。本文叙述的实验室研究就是为了探讨添加硅石以及石墨和(或)碳在各种温度下对铬铁矿还原速度的影响。在低温下(大约1300℃)添加硅石和还原剂石墨并不能促进铬铁矿的还原。在高温下(大约1500℃)添加硅石和石墨会明显地 相似文献
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介绍了矿热炉在一步法硅铬生产实践中出现的问题,通过尝试在普通高碳铬铁生产的基础上,适当增加硅铁用量、调整渣型及选择合适的供电制度等技术措施,提高了硅石还原率,从而使产品品级率大幅提高。 相似文献
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采用硅石标准样品及其复配标准样品作为校准样品,建立了熔融制样X-射线荧光光谱法测定硅石中SiO2,Fe2O3,Al2O3,CaO,MgO,K2O,TiO2,MnO,P2O5主次成分的方法。采用熔融法为试料片和校准片的制备方法,通过试验选择四硼酸锂-偏硼酸锂混合熔剂(12∶22,m/m)为助熔剂、1.00 mL LiBr溶液为脱模剂、稀释比为1∶20、熔融时间30 min。采用可变理论α系数对基体效应进行校正。对同一硅石样品进行测定的相对标准偏差(RSD)小于8%,对不同硅石样品进行测定,本法的测定结果与标 相似文献
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以特级矾土(粒径8~5、5~3和3~1mm)、棕刚玉(粒径3~1、≤1和≤0.074mm)、碳化硅(粒径≤1和≤0.074mm)和球状沥青为主要原料,金属硅和碳化硼为抗氧化剂和促烧剂,添加超微粉或焦作黏土,以硅溶胶作结合剂,采用手工捣打成型工艺来制备Al2O3- SiC- C铁沟捣打料。研究了硅微粉、α- Al2O3微粉、焦作黏土和有机防爆纤维对硅溶胶结合Al2O3- SiC- C铁沟捣打料性能的影响。结果表明:添加2%质量分数硅微粉、3%质量分数焦作黏土或0.05%质量分数有机防爆纤维对硅溶胶结合Al2O3- SiC- C铁沟捣打料的体积密度影响不大。含9%质量分数 α- Al2O3微粉的试样和含6%质量分数 α- Al2O3微粉、3%质量分数焦作黏土的试样显示出更好的常温强度。合理的颗粒级配可以提高铁沟捣打料试样的抗高炉渣侵蚀性。含6%质量分数 α- Al2O3微粉、3%质量分数焦作黏土的试样的抗渣侵蚀性最好;含7%质量分数 α- Al2O3微粉、2%质量分数硅微粉的试样的抗渣侵蚀性次之;含9%质量分数 α- Al2O3微粉的试样的抗渣侵蚀性最差。有机防爆纤维提高了捣打料的烘后强度,但使抗渣性能有所降低。硅溶胶结合Al2O3- SiC- C铁沟捣打料试样在1450℃煅烧后质量增加,有利于体积稳定性和抗渣性能。 相似文献
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S. Roy 《Mineral Processing and Extractive Metallurgy Review》2013,34(3):213-231
Detailed characterization followed by beneficiation of low-grade iron ore slime from Jilling Langalota deposit, India, was studied. The work involved separating the gangue minerals viz. quartz and kaolinite to form iron-bearing minerals, mostly hematite and goethite, as identified using XRD analysis to produce a suitable concentrate for downstream processing. The feed slime sample assayed 37.86% total Fe, 19.08% silica, and 14.4% alumina. Detailed characterization data indicated that a substantial amount of the sample was below 20 µm in size. The finer fraction contained larger amount of gangue while the coarser fraction was richer in iron. Considering the characterization data, two flowsheets were conceptualized for the beneficiation of the slime sample with two- and four-stage processing, respectively. In the two-stage operation, the grade of the slime could be improved to 60.26% Fe, 4.45% silica, and 3.98% alumina with an overall yield of about 20%. The results from the four-stage operation showed that it is possible to upgrade the iron value to 66.97% with a yield of 14.4% while reducing the silica and alumina content down to 1.7% and 1.52%, respectively. A simple flowsheet has been suggested to improve the yield substantially for the production of sinter/pellet grade concentrate from this slime. 相似文献
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矿石的化学成分、物理性能和冶金性能分析表明,PB块矿与南非块矿相比,含铁品位相当,SiO2、Al2O3、S和碱金属含量低,但P含量高,烧损大;PB块矿的粒度、冷热强度均不如南非块矿;PB块矿还原性明显优于南非块矿62.7%。鉴于PB块矿的性能,建议高炉使用时将PB块矿布在高炉中心,减少低料线操作,采取矿焦混装等措施,以改善料柱透气性。 相似文献
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研究发现,在没有经过压密处理硅灰的物理分散手段中,使用超声震荡的效果明显优于机械搅拌。使用六偏磷酸钠的效果略优于三聚磷酸钠,使用离心的方法可以做到粒度分级。最终,我们得到的最佳工艺为:首先在没有经过压密的硅灰中加入质量比1∶15的水,然后按照硅灰质量的4%加入六偏磷酸钠,经过机械搅拌使之均匀,然后,进行10min以上的超声震荡,最后以800转/min的速度离心20min,得到的悬浮液中200nm以下的二氧化硅颗粒占50%,400nm以下的二氧化硅颗粒占90%。 相似文献
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STUDY DESIGN: Prospective evaluation of spinal canal areas in 67 consecutive burst fractures between T12 and L2 treated by reduction and stabilization with a pedicle fixator. OBJECTIVES: Assessment of the efficacy of "indirect" spinal canal decompression in a large series of burst fractures. SUMMARY OF BACKGROUND DATA: Up to 50% of burst fractures cause neurologic impairment. Reduction and posterior instrumentation is the most common surgical treatment. This also reduces spinal canal encroachment by indirect decompression. No consensus exists as to the consistency and adequacy of such indirect decompression. METHODS: Spinal canal areas were measured on preoperative and postoperative computed tomography scans. The degree of encroachment was compared with clinical and radiographic variables for possible correlation. RESULTS: Spinal canal encroachment was more severe among patients with neurologic deficits than among the neurologically intact. Postoperatively, mean encroachment was reduced from 35% to 12% at T12, from 37% to 17% at L1, and from 52% to 35% at L2. Loss (and postoperative restoration) of anterior vertebral height correlated best with the degree of canal encroachment (and its reduction), especially in Denis Type A burst fractures. In Denis Type B fractures, canal compromise usually was less severe and fragment reduction better in patients older than 40 years of age than in younger patients. CONCLUSIONS: Indirect decompression in burst fractures averages about half of the preexisting encroachment. Results are usually better at T12 and L1 than at L2. Additional or secondary decompression is rarely indicated if these fractures are treated early and by experienced surgeons. Burst Type B fractures in patients older versus younger than 40 years of age differ in many respects. 相似文献
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