昆钢集团转炉钢渣资源综合利用技术应用研究

根据昆钢转炉钢渣人工矿物性质和金属铁及磁性铁嵌布特性,研发了以+70 mm大块梯级分选选铁(梯级破碎-筛选-磁选)、-70 mm分级干式磁选抛尾、干式磁选粗精矿再湿式细磨梯级分选(湿式球磨-梯级筛选金属铁-磁选磁性铁)的新工艺,具有工艺流程简单、处理量大和处理成本低、金属铁和磁性氧化铁品位和回收率高和易于分级利用的优点。同时,通过工业化生产实施建立了60万t/a转炉钢渣磁选厂,年产铁块和铁精矿6.44×104t以上,磁选尾渣用于制作水泥和免烧砖等,废水闭路循环利用。     

Optimization of magnetic separation process for iron recovery from steel slag

To improve the efficiency of iron recovery from steel slag and reduce the wear-and-tear on facili-ties, a new method was proposed by adding a secondary screen sizer to the magnetic separation process according to grain size distribution of magnetic iron (M-Fe) in the slag.The final recy-cling efficiency was evaluated by calculating the percentage of recycled M-Fe to the maximum amount of M-Fe that could be recovered.Three types of slags, namely basic oxygen furnace slag, desul-furization slag, and iron ladle slag, were studied, and the results showed that the optimized re-covery efficiencies were 93.20%, 92.48%, and 85.82% respectively, and the recycling efficien-cies were improved by 9.58%, 7.11%, and 6.24% respectively.Furthermore, the abrasion be-tween the mill equipment and the remaining slags was significantly reduced owing to the efficient recovery of larger M-Fe particles.In addition, the using amount of grinding balls was reduced by 0.46 kg when every 1 t steel slag was processed.     

比重法测定钢渣中磁性铁含量

准确测定钢渣中的磁性铁含量有利于提高钢渣磁选效率和评价磁选工艺的磁性铁回收效率。实验采用多级磁选分离的方法,通过测定钢渣磁选物以及尾渣的密度,并假设钢渣磁选物中非磁性相的密度与尾矿渣的密度相同,从而达到测定钢渣中的磁性铁含量的目的。实验选取了转炉渣、脱硫渣作为研究对象,分别测得两种钢渣的磁性铁含量为3.81%和3.72%(质量分数),平均误差为3.93%,并使用了行业标准(YB/T 140和YB/T 4188-2009)验证了测定结果的可靠性。XRD测定结果表明,磁选物的物相中含有较多磁性物,且钢渣的物相与尾渣一致,证明了测定方法假设是可行的。     

转炉钒渣中磁性物的分离

对攀钢转炉钒渣水法提钒预处理工艺中磁性物的去除进行了研究，并对磁选及筛选的原理，可行性、优化方案等进行了探索。试验结果表明，筛选分离所得非磁性物中的磁性物含量有所降低，而且磁性中夹带的钒渣量大大减少。     

Separation and Recovery of Phosphorus from P-bear-ing Steelmaking Slag

In order to recycle the phosphorus from P-bearing steelmaking slag, the influences of magnetic field inten- sities, slag particle sizes and slag compositions were investigated by magnetic separation experiments. SiO2, A1203 and TiO2 melting modification of converter slag was made respectively and phosphorus-rich phase was extracted by magnetic separation. The results show that MgO, MnO, Na2 0 and CaF2 have little effect on the phosphorus recovery, whereas the addition of SiO2, Al2 03, and TiO2 has great effect on phosphorus enrichment in slag and magnetic separation. With adding the reagent of SiO2 Al2 03 and TiO2, recycled non-magnetic substances are increased obviously and P2 05 content in nowmagnetic substances and phosphorus recovery rate are also increased. The phosphorus recovery rates of modified slag No. 8 （SiO2 modification）, slag No. 10 （AI2 03 modification） and slag No. 11 （TiO2 modification） are 84.75 %, 82.16 % and 74.46 %, respectively. Then, most of phosphorus was recycled.     

Recovery of iron and copper from copper tailings by coal-based direct reduction and magnetic separation

A technique comprising coal-based direct reduction followed by magnetic separation was presented to recover iron and copper from copper slag flotation tailings. Optimal process parameters, such as reductant and additive ratios, reduction temperature, and reduction time, were experimentally determined and found to be as follows: a limestone ratio of 25%, a bitumite ratio of 30%, and reduction roasting at 1473 K for 90 min. Under these conditions, copper-bearing iron powders (CIP) with an iron content of 90.11% and copper content of 0.86%, indicating iron and copper recoveries of 87.25% and 83.44% respectively, were effectively obtained. Scanning electron microscopy and energy dispersive spectroscopy of the CIP revealed that some tiny copper particles were embedded in metal iron and some copper formed alloy with iron, which was difficult to achieve the separation of these two metals. Thus, the copper went into magnetic products by magnetic separation. Adding copper into the steel can produce weathering steel. Therefore, the CIP can be used as an inexpensive raw material for weathering steel.     

包钢炼钢厂转炉工艺优化

炼钢和连铸生产过程中产生了大量的含铁尘泥、连铸切割渣、渣钢等含铁物质,为了减少这些含铁物质的外排和污染,在转炉中加入这些含铁物质,但是转炉工艺操作出现了波动,部分炉次钢铁料消耗较高。通过采用"留渣+双渣"工艺,在留渣的基础上将转炉吹炼分为两个阶段;同时在吹炼过程中对底吹进行控制,显著地降低喷溅发生。现有操作工艺进行优化后,钢铁料、渣料消耗大幅减少,显著地降低了转炉炼钢的生产成本。     

转炉渣热闷法直接上线工艺处理概况及应用

转炉渣含丰富的金属氧化物、微量元素及矿物,具有很高的回收利用价值。钢渣热闷法以其环保低耗、回收率高的特点被逐渐应用于钢渣的预处理工艺。简要介绍转炉渣的组成和性能及质量影响因素、焖渣工艺的原理及方法和现状,重点分析研究了某公司突破性地实现了转炉渣焖渣坑直接上线深度处理工艺。该工艺通过分坑倒入转炉渣、多次分段打水、颚破初破和棒磨机细磨后磁选等工艺、设备的优化,解决了当前焖渣工艺存在的焖坑内板结、焖后红块的问题,提高了钢渣质量性能,达到尾渣粒度最小化和金属铁回收量最大化,使其具备直接上线的能力,同时减少了扬尘污染与外排水资源浪费。该工艺实现了:焖渣坑直接上线比例达43%以上,脱碳线上线率达76.3%以上,尾渣破碎后粒度小于10 mm,且处理后尾渣含铁量小于1.06%,金属回收率得到大幅提升,对钢渣的回收利用具有指导意义。      

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In order to utilize the converter slag processed by different kinds of technological processes comprehensively, the test were conducted on converter steel slag of Jiugang processed by three kinds of technological processes as raw materials. The chemical composition of steel slag were determined by semiquantitative spectroscopic analysis and numbers of chemical analysis methods. The phases of three kinds of steel slag and iron were analyzed comparatively by X-ray diffraction (XRD), optical microscope, scanning electron microscope (SEM) and energy disperse spectroscopy (EDS), and the grain size, compressive strength, and grinding fineness of the slag were also analyzed. The result show that: the hot splashed slag could be reused after further aging, the hot braised slag can be used in construction, building materials and road engineering industry, the rotary cylinder slag can be used in construction, building materials and cement industry.     

The heat recovery simulation in the system of dry granulation of the steel slag

In present,the wet-based pattern is mainly adopted to deal with the steel slag by steel plant at home and abroad,the wet-based technology has some defects;Wasting of water,pollution of the environment,and the slag has not been fully recycled.This paper presents a new method,which is aimed to realize dry granulation,waste heat recovery and comprehensive utilizing the steel slag.According to the ideas of wind quenching granulation,the heating slag from the converter furnace,was bring to the granulation heat exchange system,through the process of breaking in a container,the granulation heat exchange system has the functions of feeding continuously and heat exchange.The heat air,through the diversion tubes,could be recycled in removing the dust.The granulation slag could be bring to a confined roller,granulating and cooling secondarily.The roller export was connected to a magnetic separator.The separated iron could be recycled,and the remaining slag could also be reused as building materials,in process of stabilization and secondary magnetic separation.The heated air could be guided into the boiler to generate the steam,which can be used to generate electricity,or use as cleaned energy,realizing the target to recycle the waste heat in steel slag.The highlights of the new method are dry granulation and waste heat recovery.This paper states the process of heat exchange between the air and the steel slag in the system of granulation heat exchange in the new technical process.In theory,it has been proved reasonable with the the system of granulation heat exchange,and also the work conditions has been optimized.     

转炉及KR循环利用钢包热态铸余渣工艺试验

为了达到节能降耗的目的,在转炉及KR进行钢包热态铸余渣循环利用的工艺试验。对比分析了转炉及KR循环利用钢包热态铸余渣前后的成渣效果和冶金效果。结果表明,在不需要对现有装备进行改造的情况下,常规炉次每炉加入约30 kg/t的钢包热态铸余渣,可节约消耗钢铁料12 kg/t、石灰4.31 kg/t、烧结矿4.87 kg/t、氧气1.83 m3/t,缩短冶炼时间3.24 min/炉,节省冶炼成本39.43 元/t(钢),降低终点a[O]含量,提高终点脱磷率,在提高钢水质量和冶炼效率、降低炼钢成本的同时,减轻了钢包铸余渣排放对环境的污染,经济效益和社会效益良好。为减小钢包铸余渣中硫含量高对转炉冶炼效果的影响,可采用将钢包热态铸余渣返回KR进行铁水预处理的方式加以循环利用,每罐铁水中加入约27 kg/t的钢包热态铸余渣后,石灰等脱硫剂用量减少82.2%,铁水预处理时间缩短1 min,温降减少4 ℃,回磷率降低2个百分点,脱硫率达到69.4%,同样取得了良好效果。     

转炉及KR循环利用钢包热态铸余渣工艺试验

为了达到节能降耗的目的,在转炉及KR进行钢包热态铸余渣循环利用的工艺试验。对比分析了转炉及KR循环利用钢包热态铸余渣前后的成渣效果和冶金效果。结果表明,在不需要对现有装备进行改造的情况下,常规炉次每炉加入约30 kg/t的钢包热态铸余渣,可节约消耗钢铁料12 kg/t、石灰4.31 kg/t、烧结矿4.87 kg/t、氧气1.83 m3/t,缩短冶炼时间3.24 min/炉,节省冶炼成本39.43 元/t(钢),降低终点a[O]含量,提高终点脱磷率,在提高钢水质量和冶炼效率、降低炼钢成本的同时,减轻了钢包铸余渣排放对环境的污染,经济效益和社会效益良好。为减小钢包铸余渣中硫含量高对转炉冶炼效果的影响,可采用将钢包热态铸余渣返回KR进行铁水预处理的方式加以循环利用,每罐铁水中加入约27 kg/t的钢包热态铸余渣后,石灰等脱硫剂用量减少82.2%,铁水预处理时间缩短1 min,温降减少4 ℃,回磷率降低2个百分点,脱硫率达到69.4%,同样取得了良好效果。     

转炉合成渣洗工艺对45钢纯净度的影响

主要研究了转炉出钢合成渣洗工艺对45钢纯净度的影响。结果表明：采用合成渣洗工艺后,铸坯中的全氧质量分数有所降低,比未合成渣洗的铸坯全氧质量分数降低2588%;采用合成渣洗工艺后,铸坯中大颗粒夹杂物含量平均由966 mg/10 kg减少为512 mg/10 kg,平均减小了4700%。     

添加剂对低品位菱铁矿制备高品位碳化铁的影响

低品位菱铁矿作为一种典型的难处理铁矿目前难以应用于钢铁行业.为了促进低品位菱铁矿的利用,提出了渗碳-磁选-酸浸制备优质电炉原料(碳化铁)的新工艺,并探究了添加剂对菱铁矿球团渗碳产物中碳化铁和脉石分离的作用机制以及对酸浸过程中碳化铁提纯效果的影响规律.结果 表明,添加剂能显著促进碳化铁颗粒长大、改善碳化铁与脉石的嵌布关系...     

转炉钢铁料消耗的探索与实践

结合舞钢120 t转炉生产实践,分析认为转炉工序影响钢铁料消耗的主要因素是转炉吹损、烟尘损失、渣中铁损和喷溅损失等。通过优化装入制度及优化转炉操作工艺减少喷溅、降低吹损、少渣冶炼等措施,钢铁料综合消耗由1092.59 kg/t降为1073.83 kg/t。     

脱磷炉利用脱碳炉返回渣的试验

为了达到节能降耗的目的,脱磷炉采用回吃脱碳炉返回渣的工艺。主要研究了脱碳炉渣的熔化特性以及作为炉料在脱磷炉中的应用效果。结果表明,通过每炉次加入约3.5t的脱碳炉渣,可平均节约1.01t石灰,4.71kg/t钢铁料消耗,脱磷炉终点炉渣的岩相组成主要由硅酸二钙、RO相、玻璃相和少量的金属铁粒组成。加入返回渣后脱磷炉终点炉渣中硅酸二钙和铁酸二钙含量有所增加,玻璃相含量降低,炉渣碱度有所升高,脱磷炉终点钢水成分控制水平有所提高。由此表明,采用脱碳炉渣返回脱磷炉循环利用减少了石灰等原辅料和钢铁料消耗,同时达到了预期的脱磷效果。     

转炉锰矿熔融还原工业试验研究

为打通转炉炼钢过程锰矿熔融还原技术路径,提高锰的收得率,对锰矿熔融还原过程和提高锰收得率的工艺参数进行了热力学探讨,并在某钢厂200 t转炉上开展了工业试验研究。研究结果表明:高效稳定的铁水“三脱”预处理技术是锰矿熔融还原技术成功的基本前提;通过理论计算,在炉渣中的(MnO)质量分数为5%～10%,终点[C]质量分数控制在0.13%～0.36%时,终点钢液[Mn]质量分数可控制在0.3%以上。工业试验主要通过采用双渣法冶炼操作,在确保前期铁水低磷的条件下尽可能控制少渣量、降低炉渣中氧化铁,从而实现加入锰矿后提高锰收得率;并在现有工艺控制条件下,锰矿加入10 kg·t?1以内时,工业试验可使锰矿还原过程锰收得率超过40%,平均为51.40%;为进一步提高锰收得率,建议严格将锰矿熔融还原渣料总量控制在40～60 kg·t?以内,石灰加入量控制在10～15 kg·t?1以内;研究结果为锰矿熔融还原技术的开发和应用提供重要参考。      

转底炉直接还原铜渣回收铁、锌技术

采用转底炉直接还原工艺,将铜渣含碳球团在高温条件下直接还原得到金属化球团和高品位氧化锌粉尘,再通过熔分或磨矿磁选方式将铁回收,得到的铁产品可作为冶炼含铜钢的原料.转底炉中试结果表明:采用"转底炉直接还原—燃气熔分"流程处理铜渣,可获得TFe品位94%以上、铁回收率93%以上的熔分铁水;采用"转底炉直接还原—磨矿磁选"流程处理铜渣,可获得TFe品位90%以上、铁回收率85%以上的金属铁粉;采用两种流程处理铜渣,均可获得锌品位60.02%的ZnO粉尘.结果表明,经过转底炉直接还原,铜渣中的铁橄榄石Fe_2SiO_4和磁铁矿Fe_3O_4相转变为含有金属铁Fe、二氧化硅SiO_2和少量辉石相Ca(Fe,Mg)Si_2O_6的金属化球团,具备通过磨选或熔分进行进一步富集的条件.     

转炉炼钢少渣冶炼技术的探索实践

介绍转炉少渣冶炼、炉渣热循环利用实践.可分两个阶段,脱碳出钢留渣、冶炼中期脱磷倒渣留渣与脱碳出钢留渣同时进行（留渣＋双渣）.脱碳留渣冶炼,通过出钢后倒渣、调渣过程控制,抑制留渣造成吹炼前期的喷溅.留渣冶炼使吨钢石灰消耗降低28.6％.“留渣＋双渣”试验,控制转炉前期炉渣碱度及全铁,选择合适脱磷渣倒炉点及温度,保证前期渣脱磷率和泡沫化,最终前期脱磷率大于60％,排渣率大于50％.“留渣＋双渣”技术,吨钢石灰消耗降低46.9％.     

铜渣与镁渣复合改质后磁选提铁的工艺研究

将工业铜渣和工业镁渣按一定比例混合后进行复合改质,对改质后混合渣进行磁选,并通过XRD、SEM分析和热力学计算对改质前后混合渣中的物相变化特征进行研究。结果表明,复合改质能够使铜渣中弱磁性富铁相铁橄榄石向强磁性镁铁尖晶石转变,并可通过磁选进行分离。碱度的降低有利于混合渣中镁铁尖晶石形成,但不利于硅酸盐相生成。本文试验范围内碱度的最佳值为2.05,在该碱度下混合渣的磁选产率和回收率分别为65.32%和79.34%,且磁选后尾渣中硅酸盐相含量相对较多。