硫酸亚铁铵滴定法连续测定铝钒锡铬合金中钒和铬

铝钒锡铬合金是冶炼钛合金的一种中间合金,为了准确、快速测定该合金中钒和铬,对硫酸亚铁铵滴定法连续测定该合金中高含量钒和高含量铬的条件进行研究并建立了测定方法。试样以硫酸-磷酸-硝酸的混酸分解后,在常温下,以高锰酸钾氧化钒,亚硝酸钠还原过量的高锰酸钾,同时用尿素分解多余的亚硝酸钠,用硫酸亚铁铵标准滴定液滴定钒,根据消耗的硫酸亚铁铵标准滴定液体积,求得钒含量;在加热情况下,将滴定钒后的溶液在硝酸银的催化作用下,用过硫酸铵溶液将钒和铬同时氧化至高价,再用硫酸亚铁铵标准滴定液滴定钒和铬的合量,两次滴定所消耗滴定液的体积之差即为滴定铬所需滴定液的体积,据此求得铬的含量。方法用于铝钒锡铬合金样品中钒和铬的测定,测定结果的相对标准偏差(RSD,n=10)分别为0.22%和0.75%,加标回收率分别在101%～105％和96％～101％之间。     

盐酸挥铬——亚铁滴定法测定碳素铬铁中钒量

研究了大量铬对低含量钒的亚铁滴定法测定的干扰及其消除方法，制定了碳素铬铁中低含量钒的测定方法。采用过氧化钠分解试样后，在硫酸一磷酸混合介质中，用高氯酸氧化－盐酸挥铬后，以亚铁还原残余六价铬，过硫酸铵氧化钒，再用亚铁滴定得到钒的百分含量。     

H_2O_2强化钒铬还原渣中钒和铬的浸出

低价钒和铬难以在碱性条件下直接反应溶出,钠化焙烧会产生较多的废气和废水,钙化焙烧则会带来较大能耗。试验以H_2O_2作为氧化剂,对钒铬还原渣中钒铬的碱性湿法浸出过程进行强化。研究了Na OH用量、反应温度、H_2O_2用量、反应时间以及搅拌转速等参数对钒铬浸出率的影响。结果表明:升高反应温度,延长反应时间,可以提高钒和铬的浸出率。在碱性条件下,低价钒比较容易被氧化成高价而溶出,即使氧化剂用量较小时,钒也比较容易被氧化;在H_2O_2的氧化作用下,钒的浸出率高达94.30%。铬的浸出率随着H_2O_2用量的增加呈现线性增加的趋势,在合适条件下,铬的浸出率高达90.12%。H_2O_2作为一种清洁的氧化剂,在反应过程中不会引入杂质,并且能够实现钒和铬的同步高效浸出。该方法具有对环境友好、反应效率高等优势,可以作为一种新型高效氧化技术进行应用。     

钢液中钒的回收和传质动力学

本文研究了不同钒含量的钒铁在三种不贩加入方法下，钢液中钒的回收率和质量舆动力学。钢液制备是在感应炉用９０ｋｇ工业纯铁熔炼，钢液熔也用硅脱氧，温度保持在１６００℃左右稳定不变，此外，为了减少大气对钢液的氧化，在钢液上部采用氩气保护，钢铁加入量根据实际生产钢中钒含量不超过０．１２％。对不同级别的钒铁，钒的回收率可达９５％，但钒的回收速率受钒铁钒含量和加程序设的影响，在相同的加入方法下，４３％钒含量的钒     

亚熔盐尾渣中全钒、可钒、全铬、可铬的分析

在15%～20%硫酸酸度下,用过硫酸铵将四价钒氧化为五价钒,用硫酸亚铁铵标准溶液滴定钒含量。在加热状态下,以硝酸银为催化剂,用过硫酸铵将铬氧化成六价,用硫酸亚铁铵标准溶液滴定钒铬总量。     

钢中钒的测定方法试验

本研究了用高氯酸溶样，硝酸破坏碳化物，冒烟后，在磷硫混酸中，再次用高锰酸钾将低价钒氧化成五价。然后用硫酸亚铁铵标准溶液进行滴定。该法采用了快速溶样、两次氧化，测定结果稳定、重现性好。可测定普钢中0．01％-0．5％范围内的钒。     

快速容量法测定钒铁中钒

钒铁中钒的测定,通常用高锰酸钾氧化法,其操作手续较繁,测定速度较慢,且在室温较高的条件下,铬易产生干扰.本文用高氯酸作钒的氧化剂,甲醛还原高价铬,以苯代邻氨基苯甲酸或其被预氧化的绿色悬浊液为指示剂,用硫酸亚铁铵标准溶液滴定.本法快速、准     

钒渣中钒和锰的连续测定

钒渣中多元素的连续测定已有许多方法,我们发现,在磷酸溶样硝酸处理下,以硝酸铵可以把钒渣中的钒全部氧化成五价,同时把锰氧化成三价。用苯代邻氨基苯甲酸为指示剂,以亚铁标准液滴定至亮黄绿色为锰和钒的合量(V_1),在该溶液中用H_2SO_4调成酸度为15％,按常法以高硫酸铵为氧化剂煮沸分解后仍以上述指示剂并用同样亚铁标准液滴定至终点乃是钒的含量(V_2),V_1—V_2为含锰量,本法条件宽容、操作迅速,误差可满足生产要求。     

二安替比林苯乙烯甲烷光度法测定钢中微量钒

二安替比林苯乙烯甲烷光度法测定钢中微量钒庄明福,蒋凤华（无锡锅炉厂,无锡,２１４０２６）（无锡农机厂）利用催化氧化原理测定钒的二安替比林苯乙烯甲烷（ＤＡＰＶＭ）光度法灵敏度较高￣［１２］,很适于微量钒测定,但普通钢铁中铬、钒经常共存（且铬量远大于钒量...     

合金钢中锰、铬元素连续快速测定研究

本文介绍一种新型炉前分析方法，用于同时测定合金钢中的锰，铬元素含量，取代了传统单独分析锰、铬元素方法，应用效果良好。测定范围锰：0．50-5．00％，铬：0．50-5．00％。     

提钒尾渣中钒铬的浸出与萃取

采用硫酸浸出和萃取分离从提钒尾渣中回收有价元素。结果表明,尾渣经80%质量浓度的硫酸溶液浸出后,钒、铬浸出率分别达98.2%、84.8%;以20%P204+80%磺化煤油(体积百分数)为萃取剂,对浸出液进行三级萃取并反萃后,钒的回收率可达56.2%,萃取过程中铬的损失率低于4%,萃余液水解后可得到纯度为89.6%的Cr_2O_3产品。实现了浸出液中钒、铬的分离和回收。     

攀枝花钒钛磁铁矿冶炼过程中主要稀散元素分布走向研究

本文以攀枝花矿区所产多元素共生钒钛磁铁矿作为基本原料的钢铁冶炼和选钛工艺流程为主线,具体针对攀钢钒冶炼工艺流程的技术特点和关键控制环节,重点选取烧结矿、高炉渣、钒渣、钢渣等样品作为稀散元素分布走向研究的监测和调查对象,开展了镓、钪、铬、钴、镍、铌、锆的调查研究.通过资料调研和检测分析,尤其是引入富集比和总回收率的概念,综合对比分析,从必要性和可能性两个方面阐明了攀枝花矿(攀钢钒)应重点考虑钒渣中铬、铌元素和高炉渣中镓、钪、锆元素为综合利用的可行性及主攻方向,为进一步深入全面地综合开发利用攀枝花钒钛磁铁矿资源提供了可靠的依据.     

Experimental study on slag splashing with modified vanadium slag

Slag splashing is the most effective technology to improve the furnace campaign of converter; however, due to the great difference of composition between the vanadium slag and the steel slag, the technology has not been applied in the vanadium extraction converter. To solve the serious problem of lining erosion in the vanadium extraction converter, in this paper, slag splashing with modified vanadium slag was studied. The results showed that the purpose of adjusting the state of vanadium slag can be achieved through the modification. The modified slag had good slag splashing performance. After slag splashing, the thickness of the furnace was increased by more than 10?mm. The content of CaO in the modified vanadium slag can be controlled less than 3%, and the quality of vanadium slag and semi-steel was not obviously affected. The metallic iron content in the slag was greatly reduced, which was beneficial to reduce the iron loss in the vanadium extraction process.     

Extraction of vanadium from direct acid leach solution of converter vanadium slag

Direct acid leaching of converter vanadium slag by titanium dioxide waste is eco-friendly and efficient, but with low selectivity. This novel technique can result in a vanadium solution which contains chromium(III), aluminium(III), magnesium(II), manganese(II) and high amount of iron(II) and iron(III). Bis (2-ethylhexyl) phosphoric acid (D2EHPA) and tri-butyl-phosphate (TBP) diluted with sulphonated kerosene were applied for vanadium extraction from the multi-element leach solution. The effects of the initial pH, concentration of D2EHPA, ratio of organic to aqueous phase, and the extraction time on the extraction efficiency of vanadium were investigated in saponification and unsaponifiable systems, respectively. The results showed that the vanadium extraction percentage can be up to 97% and the iron extraction percentage can be less than 10% in a thirteen-stage counter-current simulation test and the separation coefficient between vanadium and iron can reach to 109.8. Furthermore, vanadium(IV) can also be separated from other impurities such as aluminium(III), magnesium(II), manganese(II), chromium(III) efficiently. The loaded organic phase was stripped by 184?g?L^?1 sulphuric acid solution in a three-stage counter-current stripping process and with the total vanadium stripping percentage of greater than 99.5%. In the end, the vanadium pentoxide products with a purity of 99.14% were obtained.     

黄山低钒低碳石煤处理新工艺研究

针对皖南黄山地区石煤低钒低碳的特点,提出了"浮选脱碳(精煤)-碳(精煤)焙烧浮选钒矿-酸浸物料-萃取提钒"的工艺方法。生产实践表明:该工艺钒的总回收率可达75.10%,所得V2O5产品质量符合GB 3283-87冶金98级要求,此工艺在提高钒回收率的同时,对石煤中的碳也实现了综合回收利用。     

Effects of Cr and V additions on the microstructure and properties of high-vanadium wear-resistant alloy steel

The effects of chromium and vanadium additions on the microstructure, hardness and wear resistance of high-vanadium alloy steel (containing 5–10 wt-% V and 2–10 wt-% Cr) were studied by means of optical microscopy, scanning electron microscope (SEM), X-ray diffraction (XRD), energy dispersive spectrometer (EDS), Vickers hardness and Rockwell-hardness tester & M-200 ring block wear tester. Researching results showed that the solidification structure of high-vanadium wear-resistant alloy steel was mainly consisted α-Fe (martensite), vanadium carbide (VC), M₃C and M₇C₃. Vanadium is mainly distributed over VC, and certain amount of vanadium exists in the matrix and M₇C₃ type eutectic carbide. Chromium is mainly distributed over the M₇C₃, and the matrix also contains a small quantity of chromium. It is found that the content of VC increases with the increase of vanadium content when carbon and chromium contents are constant. The change of micro- and macro-hardness was not obvious with the increase of vanadium content. The content of M₇C₃ type eutectic carbides increases gradually with the increase of chromium content when carbon and vanadium contents are constant. The micro- and macro-hardness increases with the increase of chromium content. The increase of vanadium content brings to the increase of wear resistance of alloy steel when carbon and chromium contents are constant. The change of chromium content had no obvious effect on wear resistance of high-vanadium alloy steel when carbon and vanadium contents. The increase of vanadium content brings to the increase of wear resistance of alloy steel when carbon and chromium contents are constant. The wear resistance of as-cast high-vanadium alloy steel is the best when the content of vanadium and chromium is 10 wt-% and 5 wt-% respectively.     

含钒硅铁水CO_2脱硅保钒实验研究

以含钒生铁为原料,进行脱硅保钒处理,得到低硅含钒生铁,为下一步转炉提钒获得高品位钒渣奠定基础.本文利用MoSi_2炉和石墨坩埚以CO_2为氧化剂,研究了温度和CO_2气体流量等因素对含钒硅铁水中硅和钒含量的影响.结果表明:当温度在1 450℃左右、CO_2流量控制在1 L/min、一定强度的搅拌时,对脱硅保钒有利,脱硅率高达68.62%,而钒氧化率仅为0.73%.     

含钒转炉钢渣中钒的提取与回收

针对攀钢目前含钒铁水的工艺流程和含钒转炉钢渣中V2O3含量,提出了从含钒钢渣提钒的新的技术思路和工艺,并对新工艺的关键环节——含钒钢渣冶炼和高钒铁水提钒进行了试验研究。结果表明：采用矿热炉冶炼含钒钢渣,生铁中钒的质量分数达7．45％,对含钒生铁进行提钒,钒渣中V2O3;的质量分数达35．06％,实现了钒资源的有效提取和综合回收。     

钒钛硅铁复合合金的开发与应用

对以攀钢雾化钒渣为原料不经化学处理直接冶炼钒钛硅铁复合合金的试验进行了研究。钒渣经预还原后可大幅度提高V2O5含量和V/Fe。预还原钒渣用硅铁还原可得到V—20％，Ti2％—3％，Si—20％的钒钛硅铁复合合金。产品用于炼钢试验，效果良好。     

某石煤钒矿的工艺矿物学研究

研究某石煤钒矿的工艺矿物学特性,查明了矿石中钒元素的赋存状态及主要矿物的嵌布特征,并就影响提钒工艺的矿物学因素进行了分析。结果表明,矿石中88.02%的钒呈类质同象分布于硅酸盐矿物中,6.00%分布于褐铁矿中,4.20%以钒钛氧化物形式独立存在,少量钒以钒酸盐形式存在。含钒硅酸盐矿物主要以隐晶质或胶状结构产出,并与微晶石英及炭质紧密胶结在一起,焙烧、高酸浸出(钒浸出率仅64%)难以破坏其结构。提钒工艺的选择应重视选矿富集钒或选矿抛弃耗酸矿物。