大方坯结晶器内液面波动与卷渣行为

为深入揭示不同水口类型对结晶器内钢液初始流动的影响,以某厂410 mm×530 mm的大方坯结晶器为原型,基于相似原理,采用1:1的物理模型,比较了直通型、五孔和四孔水口浇注时在不同拉速和浸入深度下的结晶器内液面波动和渣层状态。结果表明,3种水口的液面平均波高范围分别为0.20~0.30、0.23~1.10、0.35~1.28 mm。五孔水口和四孔水口的液面波动均比直通水口剧烈,渣层比直通水口活跃,尽管有轻微卷渣但无裸钢现象,这有利于保护渣的熔化和夹杂物的上浮去除。五孔水口和四孔水口对结晶器壁面的冲击比直通水口强,有助于铸坯中心等轴晶率的提高。推荐该大方坯使用多孔水口时浸入深度和拉速分别为170 mm和0.38 m/min,可保证生产顺行和铸坯质量改善。     

B2O3对高铝渣稳定性的影响

为了明确B₂O₃对高Al₂O₃渣稳定性的影响,基于现场高炉渣的实际成分,通过熔体物性测定仪、扫描电镜、红外光谱仪分析了B₂O₃对高Al₂O₃渣黏度和基础玻璃微观结构的影响。结果表明,随着B₂O₃含量的增加,炉渣黏度降低;当炉渣温度低于1 360 ℃时,炉渣随着B₂O₃的增加稳定性增强;炉渣温度为1 216 ℃、B₂O₃质量分数为2.0%时,炉渣的稳定性最好。随着B₂O₃含量的增加,炉渣不断玻璃化,当B₂O₃质量分数为2.0%时,炉渣微观结构完全是玻璃态结构,表现为假性酸性渣的性质;随着B₂O₃含量的增加,[Si-O-Al]键断裂,[AlO₆]八面体结构振动峰增加,炉渣的稳定性越来越好。     

硫酸法常压浸出镍铁渣中镁的正交试验及动力学分析

镍铁渣产量大,富含Mg元素,具有较高的回收价值。基于镍铁渣成分及矿相结构等特性,采用常压硫酸浸出法,研究镍铁渣中Mg的浸出反应规律和影响因素。结果表明,在液固比20∶1、浸出温度180℃、浸出时间120min、硫酸质量分数80%的条件下,镁浸出率达到83.73%。该浸出受界面化学反应控制,表观活化能12.72kJ/mol。     

铜闪速吹炼渣型的控制实践

采用铜悬浮吹炼炉生产时的棒渣样状态与化验结果相结合的方式探讨铜闪速吹炼渣型的控制手段。实践经验表明:吹炼渣型异常时,最直接最快速的表现形式即是棒渣样状态,通过棒渣样状态和化验数据的关联性可做前馈控制,避免因化验的延时性造成炉况继续恶化,再根据化验结果精准调节,可快速调整闪速吹炼渣型。     

镍铁渣在混凝土综合利用中的环境风险研究

从浸出机制和迁移扩散角度出发,研究了镍铁渣的产酸潜势、浸出毒性和其混凝土产品的浸出毒性。结果表明,镍铁渣产酸潜势为不产酸,本身不是一个酸性排放源;腐蚀性、浸出毒性小于国家标准限值。镍铁渣混凝土产品在酸性和碱性环境下,只有砷少量浸出,但未超过《地下水质量标准》。因此,镍铁渣可以直接入场作为混凝土掺和料进行综合应用,环境风险较小。     

滚筒法不锈钢钢渣处理技术的研究和应用

不锈钢钢渣的环保化处理是钢铁行业面临的难题之一,不锈钢钢渣中高含量游离CaO与MgO导致浸泡处理时粉化严重,环境污染大;不锈钢钢渣中不稳定的六价铬易溶于水造成水体污染。通过对滚筒法处理不锈钢钢渣的工艺抑制不锈钢钢渣粉化和抑制Cr3+的氧化析出进行研究和机理分析,并结合工程实例应用,论证了采用滚筒法处理不锈钢钢渣的可行性,为不锈钢钢渣环保化处理和资源利用奠定了基础。     

Simulation on Slag Splashing for LD Converter

SeveraL parameters affecting slag splashing in LD converter have been discussed. Using parffin and starch model, a simulated test about 30 t converter has been made in laboratory and the modified Frode numberwas chosen as the main similar basis of the system. It was results that the optimized slag splashing parameters wasobtained through data treatment The nitrogen gas flow rate is about 8 500 m3/h, the splashing time is of 3 min,and the lance height is of 0.8 m. It is necessary to add MgO or carbon into the slag to adjusting slag composition.Also, it is difficult for the splashed slag condensing on the line when the slag temperature is much higher     

Synthesis of mesoporous geopolymeric powder from LD slag as superior adsorbent for Zinc (II) removal

Linz-Donawitz(LD) slag Geopolymer(LDSGP), a porous aluminosillicate geopolymeric adsorbent, has been synthesized from steel plant LD slag for efficient removal of Zinc(II) ions from wastewater, thus presenting a solution for converting industrial waste to adsorbent for wastewater treatment. The colloid paste of raw LD slag and the alkaline activator (10?M NaOH?+?sodium silicate (1:1 w/w)) has been cured for 3?days at low temperature to geopolymerize the calcium oxide rich LD slag. The BET surface area of LDSGP adsorbent (30.84?m²/g) has improved considerably compared to raw LDS (4.85?m²/g) and the FESEM and HRTEM images reveal the presence of micropetal and cauliflower like structures at outer surface of the adsorbent particles. The mesoporous nature of LDSGP adsorbent can be understood by analyzing N₂ adsorption-desorption and pore size distribution plot. The PXRD pattern of LDSGP adsorbent powder confirms the presence of Ca₂SiO₄ and Ca₃SiO₅ in the geopolymeric matrix. Langmuir isotherm model correlates the batch adsorption data of Zn²⁺ ions onto LDSGP particles at 298?K, 308?K and 318?K. The maximum Zn²⁺ ions adsorption capacity of LDSGP is 86?mg/g at 318?K. The adsorption kinetic data is correlated with pseudo-second-order model indicating chemisorption of Zn²⁺ ions onto LD slag geopolymeric powder adsorbent.     

La2O3对高钛高炉渣制备微晶泡沫玻璃的影响

利用高钛高炉水淬渣和废玻璃粉为基础原料,以CaCO_3为发泡剂,Na2B4O7·10H_2O为助熔剂,Na_3PO_4·12H_2O为稳泡剂,通过"一步法"烧结制备微晶泡沫玻璃,研究了La_2O_3的添加对微晶泡沫玻璃物相、结构及性能的影响。结果表明,添加La_2O_3对晶相种类改变不明显,但会提高晶化程度。随着La_2O_3添加量由0%(质量分数,下同)增至1.5%,微晶泡沫玻璃的气孔孔径减小,晶粒由粒状变为短棒状,微晶泡沫玻璃的体积密度、抗压强度升高,气孔率、吸水率和导热系数降低。La_2O_3添加量继续由1.5%增至3.5%,微晶泡沫玻璃的气孔孔径增大,晶粒尺寸逐渐变小直至呈现无规则形状,微晶泡沫玻璃的体积密度、抗压强度降低,气孔率、吸水率和导热系数升高。当La_2O_3添加量为1.5%时,所制得的微晶泡沫玻璃的综合性能最佳。