低钙铝酸钙熟料的物相转变和浸出性能

以分析纯CaCO_3,Al_2O_3和SiO_2为原料,研究了n_(CaO)/n_(Al2O3)=1.0,w_(Al2O3)/w_(SiO2)=3.0时物料的熔化温度以及熟料的物相组成、自粉化性能和氧化铝浸出性能.结果表明:物料熔化温度为1 392℃;烧结温度为1 350℃时熟料物相为CaAl_2O_4,Ca_(12)Al_(14)O_(33)和γ-Ca_2SiO_4,自粉化性能和氧化铝浸出性能良好,氧化铝浸出率为93.37%;1 400℃物料局部熔化,非均相的形成造成物料扩散受阻和物相分布不均匀,阻止β-Ca_2SiO_4向γ-Ca_2SiO_4转化,熟料自粉化性能变差,且有Ca_2Al_2SiO_7生成,二者均使氧化铝浸出性能变差,氧化铝浸出率仅为74.50%;1 450℃物料完全熔化,熟料自粉化性能和氧化铝浸出性能得到改善.     

探讨盘锦地区用生石灰替代水泥加固软土地基的意义

饱和软土是盘锦地区工程土质的一般特征,人工地基加固的问题上比国内一般地区要复杂得多,而且建设投入也大。本文通过笔者参与的一项工程实例,而对石灰桩加固技术的方案和效果做了整体设想和验算,然后比照水泥桩实施方案对各项指标进行优劣判定,最后得出用石灰取代水泥加固地基的可行性和环保意义。     

两段烧结工艺中的Ⅰ段赤泥烧结

研究了铝土矿两段烧结工艺的Ⅱ段烧结及溶出的最佳操作条件，确定Ⅰ段赤泥在钙比为２３５，烧结温度为１１２０～１２００℃时，氧化钠溶出率达９２％左右，氧化铝溶出率达８１％左右；当溶出液氧化铝质量浓度为４０～８０ｇ／Ｌ时，Ⅱ段熟料溶出的二次反应很弱，溶出条件宽松．因此，两段烧结新工艺处理铝硅比为６的矿石，氧化钠总溶出率达９８６％，氧化铝总溶出率达９６８％，碱的化学损失是每吨氧化铝损失碳酸钠１８ｋｇ．     

烧结矿低温还原粉化性能试验方法释疑

一方认为:用国家标准"铁矿石还原粉化试验静态还原后使用冷转鼓的方法"(GB/T 13242-91)做试验时,由于有缓冷过程,试验结果是不可靠的.另一方则认为:标准已执行多年,应该没有问题.为解决争论,在实验室进行了试验.结果表明:烧结矿在还原后的缓冷过程不产生粉化,相反略显抑制粉化;烧结矿在不还原的缓冷中也不产生粉化.国标GB/T 13242-91没有问题.     

莫来石结合碳化硅制品的研制

以 A2 S2 作为 Si C颗粒间的结合相 ,其烧结体具有高温强度大 ,热震稳定性好 ,抗氧化能力强 ,热膨胀系数小等特点。     

EAF steelmaking process with increasing hot metal charging ratio and improving slagging regime

A new electric arc furnace (EAF) steelmaking process with increasing hot metal charging ratio and improving slagging regime simultaneously was developed and applied in a 50 t electric arc furnace for more than a year at No. 1 Steelmaking Plant of Shanxi Taigang Stainless Corporation Limited. The essential fact of the new EAF steelmaking process was to charge hot metal in two portions or steps: firstly, 35wt%-40wt% hot metal was pretreated by blowing oxygen in a specially designed reactor for decar burization and improving hot metal temperature and melting premelted slag; secondly, 30wt% hot metal was charged into EAF with high basicity refining slags from ladle furnace (LF)-vacuum degassing furnace (VD) refining process. The results show that the hot metal charging ratio can reach to about 65wt%-70wt% for the new EAF steelrnaking process; meanwhile, the tap-to-tap time of a 50 t EAF can shorten by 5-10 min, the electricity consumption can decrease by 35-50 kW·h/t, the lime consumption can reduce by 10.5 kg/t of molten steel, and the content of harmful heavy metals in molten steel can be easily controlled to less than the upper limits of aimed steel specification or grade compared with the traditional EAF steelmaking process. In addition, the dephosphorization ability shows a slight strengthening, however, a small degree of lessening for desulphurization ability is observed for the new EAF steelmaking process, but the weakness of desulphurization ability cannot become an obstacle to its further application since a stronger desulphurization ability can be achieved during secondary refining of LF coupled with VD after EAF steelmaking process.     

Application of Optimal Sinter Burden Design

The application of the optimal sinter burden design in the sinter shop of No.1 Iron-making Plant in Tangshan Iron & Steel Corp was reported. By using burden calculation and simulating production under different situations, it is demonstrated that the technology can providethe relevant information in product quality and cost etc. for decision-makers. The technology has been used to guide production of the Sinter Shop since 2000, and a remarkable achievement has been obtained.     

烧结矿矿相显微图像识别及系统开发

为了快速、准确地获得烧结矿矿物组成,研究开发了烧结矿矿相显微图像识别系统。在分析不同碱度烧结矿矿相特征的基础上,确定了图像识别算法的原则;并研究对比分水岭、模糊C-均值(FCM)和区域生长这3种识别算法。研究结果表明:区域生长算法比较适合于烧结矿矿相显微图像的识别;应用VC++2003.net开发了烧结矿矿相显微图像识别系统,其识别结果与专家分析结果相比,相对误差小于5%,达到了烧结矿矿相识别的精度要求。     

聚丙烯纤维与TG固化剂对水泥石灰土强度及稳定性的影响

为提高水泥石灰综合稳定土的基层性能,选用聚丙烯纤维、TG土壤固化剂改良水泥石灰土。根据水泥和石灰含量、聚丙烯纤维掺量、TG固化剂剂量对水泥石灰土无侧限抗压强度的影响规律,从而确定水泥和石灰含量均为4%,聚丙烯纤维和TG固化剂掺量分别取0.2%、0.02%。在此基础上,研究了纤维与固化剂对水泥石灰土劈裂强度、收缩性、水稳定性及冻稳定性的影响。试验结果表明:经聚丙烯纤维与TG固化剂复合固化的水泥石灰土强度及稳定性提高效果最显著,优于高石灰掺量的水泥石灰土。     

海湾相有机质浸染砂的固化试验研究

海南省沿海地区分布着一种特殊的有机质浸染砂,单纯采用水泥作为固化剂的深层搅拌法不能有效提高其力学强度,因此选用不同材料做外掺剂对其进行了大量的固化试验。通过不同水泥、不同水泥掺入比、不同固化材料及其掺入比、不同水灰比和龄期下水泥土的无侧限抗压强度试验以及微观结构试验,研究了有机质浸染砂的最优固化材料及水泥土的配合比;分析了水泥土的力学行为、变化规律和加固机理,发现单纯采用水泥不能有效加固海湾相有机质浸染砂的原因是水泥的水解水化作用会发生延缓,以及砂颗粒与水解水化产物的作用受到阻碍,掺入适量的熟石灰可获得较好的加固效果。