从含铁尘泥中分选铁的试验研究

含铁尘泥是钢铁冶炼过程中除尘器收集下来的一种细粒状固体物质，其钾、钠、氟含量较高，严重制约其返烧结工艺，为寻求利用途径，从含铁尘泥中进行分选铁的试验，这样既可提高铁品位又降低了杂质含量，不仅为烧结提供了优质铁原料，又综合利用了含铁尘泥，具有很好的社会经济环境效益。     

铁矿石中全铁含量分析的研究进展

对目前铁矿石中全铁含量的检测方法包括化学分析法、仪器分析法以及微量滴定法等进行了全面的分析和阐述。比较了不同化学分析法中还原方式、滴定剂等的差异以及对检测结果稳定性和准确度的影响, 分析了铁矿石中全铁含量测定常用的仪器分析法即电位滴定法和X射线荧光光谱法的发展和改进, 介绍了近年来新兴的微量滴定法在铁矿石中全铁含量测定中的应用。对不同方法的优势和不足进行了比较和评价, 为进一步发展和完善铁矿石中全铁含量检测的新方法提供了参考和依据。     

碘量法测定铁矿石中全铁及磁性铁的分析方法探讨

采用碘量法对不同类型铁矿石尤其是常规酸、碱分解方法难以分解完全的矿石中铁的测定进行分析研究,使用过氧化钠碱熔法测定全铁,并对传统磁性铁测定方法进行了改进。分析了不同酸度、碘化钾加入量、放置时间对测定结果的影响,以及干扰元素的影响及去除。实验方法全铁分析时过氧化钠加入量确定为3.0g,磁性铁分析时过氧化氢加入量确定为1滴(300g/L);全铁和磁性铁分析反应起始酸度控制在0.5~1.0mol/L,临近终点酸度控制在pH值为3.0~4.0;碘化钾溶液加入量为10mL(250g/L);并成功地分离了干扰元素。选取不同类型和含量的铁矿石标准物质和实际样品分别采用实验方法和传统的重铬酸钾无汞滴定法对全铁和磁性铁做方法对比试验,实验方法的测定结果与认定值或铬酸钾无汞滴定法的测定值基本一致。实验方法全铁测定结果的相对标准偏差(RSD)在0.076%~0.19%之间,磁性铁测定结果RSD在0.083%~0.13%之间,正确度与精密度均符合DZ/T 0130—2006质量管理规范的要求。     

二溴对硝基偶氮氯膦光度法测定硅铁中铁

在0.072 mol/L的盐酸介质中,显色剂二溴对硝基偶氮氯膦与铁发生显色反应,形成了摩尔比为2∶1的络合物。该络合物的最大吸收波长位于610 nm处,铁量在0.14~0.80μg/mL范围内符合比尔定律,测得络合物的表观摩尔吸光系数为1.63×104L.mol-1.cm-1。所拟方法用于硅铁标样中铁的测定,测定值与认定值相符,RSD在1.4%~2.1%之间(n=6)。     

Comparison of the metabolism of 2 injectable iron preparations (sorbitol iron and polymaltose iron) with the metabolism of transferrin and hemoglobin iron

Iron distribution in the different organs and chemical compartments of the rat has been studied after intravenous injection of 59Fe-sorbitol (Jectofer-Astra) and 59Fe-polymaltose (Fer Hausmann Lucien) and compared with the metabolism of 59Fe bound to transferrin and to hemoglobin. Both parenteral iron preparations are utilized more slowly than Iron-transferrin. The speed of red cell incorporation of 59Fe from sorbitol is similar to the hemoglobin iron utilization (half incorporation in red cells: 4 to 5 days). Iron polymaltose is much more slowly utilized (half incorporation in the red cells: 13 to 15 days). One third of the 59Fe from sorbitol is eliminated in urine, the remaining iron being taken up to 60% by the liver and to 30% by the bone marrow. It is very quickly catabolized, since as early as the first hour after injection most of the 59Fe is bound to polymaltose till the 14th day. Between the third and fourth week 25% of the 59Fe from polymaltose is found in hemosiderin. These metabolic differences are also found in man: 59Fe from iron sorbitol is found in urine after injection, is mobilized by desferrioxamine after six days, and eliminated through dialysis membranes. On the other hand the 59Fe from polymaltose is slowly but completely utilized and not mobilized by desferrioxamine in the first week after injection. The data give the indications for use and the pharmacokinetics of two forms of parenteral iron and oral preparations in the treatment of iron deficiency.     

Studies on induction hardening of gray iron and ductile iron

The effect of induction case hardening of a gray cast iron (FG 260) and SG iron (600/3) as a function of applied induction power has been studied. The influence of various operating parameters on the penetration depth has been analysed. The case depth as a function of applied power and the associated changes in microstructure has been investigated. The case depth of SG iron was found to be twice than the gray iron due to higher resistivity of the material and increase in depth of penetration. Both hardness and the depth of penetration increased with increase in applied power associated with martensitic case formation. The surface hardness of both the irons varies between 600 to 800 VHN. The core microstructure in both the irons displayed pearlitic matrix. In the case of SG iron, the nodule size, sphericity and nodularity have reduced in the induction hardened case compared to the core.     

Gaseous reduction of iron oxides: Part III. Reduction-oxidation of porous and dense iron oxides and iron

The internal reduction of high-grade granular hematite ore in hydrogen and carbon monoxide, and also the internal oxidation of porous iron granules in CO₂-CO mixtures have been investigated. To assist the interpretation of the rate data for porous iron and iron oxides, rate measurements have been made also with dense wustite, previously grown on iron by oxidation. The iron formed by reduction of dense wustite is porous, similar to that observed when porous hematite is reduced. It is found that the rate of dissociation or formation of water vapor or carbon dioxide on the iron surface is about an order of magnitude greater than that on the surface of wustite. The results of the previous investigations using dense iron and wustite are in general accord with the present findings. The rate of reduction of hematite increases with increasing pore surface area of the reduced oxide. The results indicate that the rate of reduction of granules is controlled primarily by the formation of H₂O or CO₂ on the pore walls of wustite. The specific rate constants evaluated from internal reduction, using the total pore surface area, are about 1/50 to 1/100 of those for dense wustite. These findings indicate that with porous wustite or iron, the effective pore surface area utilized is about 1 to 2 pct of the total pore surface area. The rate of reduction in H₂-CO mixtures is in accord with that derived from the rate constants for reduction in H₂ and CO.     

铁矿石中磁性铁的测定方法研究

研究了应用WFC-3型磁选仪测定铁矿石中磁性铁的分析条件。利用超声波粉碎办法进行试样预处理,用本法和人工磁选法分别测定铁矿石标样中磁性铁,本法测定结果高于人工磁选法并接近于标准值,RSD小于0.5%,回收率为99.1%~100.1%。方法快速准确,操作简便,已用于铁矿石中磁性铁的日常检测,获得了满意结果。     

X射线荧光光谱法测定复合碳铁合金中总铁含量

探讨了应用熔融法制样,X射线荧光光谱法分析碳铁中TFe的最佳制样条件和测量条件。本方法通过试验选择750 ℃烧碳温度去除碳铁中游离碳,再选择硝酸钾和碳酸锂作为氧化剂,以及合适的氧化温度,将试样预氧化处理,再高温熔融,并通过加入钴元素作内标,校正基体效应和烧失量。在选定的实验条件下,对一复合碳铁试样进行了11次测定,RSD为011%。对4个复合碳铁实际样品进行测定,结果与湿法测定结果相符。     

X-射线荧光光谱法测定铁矿石中全铁

X-射线荧光光谱法广泛应用于测定铁矿石中杂质成分和铁含量,但有关标准仅把铁含量作为参考数据用于计算基体效应。通过大量的比对试验发现,采用高纯度试剂人工合成校准样和利用标准曲线法直接测定铁含量准确度较高,可以作为全铁的测定方法。本法具有前处理简单、测定速度快、节省人力物力等优点,还可以同时测定铁矿石中二氧化硅、氧化铝、氧化钙、氧化镁、磷、锰、二氧化钛等杂质。     

X射线荧光分析法测定铁矿石中全铁

铁矿石中全铁的含量范围通常较宽,因此需要高的分析精确度。尽管熔融制样法已经被普遍用于铁矿石的X射线荧光光谱分析,但作为样品制备的另一种方法,压片法由于简便、快捷的特点,其应用需求同样较大。康普顿散射比法已经被普遍用于岩石等样品中的重金属元素测定,其中荧光X射线与X射线管线发射的康普顿散射X射线的强度比被用作校正。不过,这种方法不能为矿石和精矿中高含量重金属元素的测定提供足够的准确度。本研究建立了一种新的方法,在元素间校正项中,将基本参数法获取的理论α系数用于康普顿散射比校正。本方法可以将铁矿石中全铁含量的测定准确度提高到0.14%（质量分数）。     

利用攀西铁矿制备微合金铁粉的中试生产

为了降低还原铁粉生产成本并改善其性能,开展了利用攀西铁矿连续制备微合金铁粉的中试生产。通过严格控制直接还原铁料和一次铁粉的质量及稳定性,采取催化还原—磨选—精还原工艺流程,并在实践中不断优化流程,有效弥补了攀西低品位、高脉石铁矿对制备微合金铁粉品质及稳定性带来的不利影响。中试生产表明:在w(TFe)60.0%、w(Si O2)2.0%、w(Al2O3)1.5%条件下,可以批量得到氢损小于0.20%、w(C)0.020%、w(S)0.030%、w(TFe)98.5%、金属化率大于99.0%的微合金铁粉。同时,找到了降低有害元素对钢带炉炉型危害以及稳定还原气氛的方法,加工成本显著降低。     

硫酸铈滴定法测定铁矿中铁

提出在HCl介质中,以抗坏血酸还原铁 ,残余的抗坏血酸以次甲基蓝为指示剂,硫酸铈氧化,然后在硫 磷混酸介质中,以二苯胺磺酸钠为指示剂,硫酸铈标准溶液滴定铁 。大多数常见离子不干扰铁的测定,氟的干扰可用硼酸消除。本方法简便、快速,用于铁矿中铁的测定,结果满意。