白水泥闭路粉磨系统选粉机的改造

白水泥作为一种特种水泥,水泥成品要求比表面积高,80μm、45μm筛余细度控制严格.改造前,水泥粗颗粒多,细度不易控制.将原系统中O-Sepa N-1500水平涡流选粉机更改为SLK1500型空气打散涡流选粉机,改善了物料打散效果,提高了选粉机选粉效率和台时产量,解决了粗颗粒窜入成品影响质量的问题.     

Electrostatic-lenses position-sensitive TOF MCP detector for beam diagnostics and new scheme for mass measurements at HIAF

A foil–microchannel plate(MCP) detector,which uses electrostatic lenses and possesses both good position and timing resolutions, has been designed and simulated for beam diagnostics and mass measurements at the next-generation heavy-ion-beam facility HIAF in China. Characterized by low energy loss and good performances of timing and position measurements, it would be located at focal planes in fragment separator HFRS for position monitoring, beam turning, Bρ measurement, and trajectory reconstruction. Moreover, it will benefit the building-up of a magnetic-rigidity–energy-loss–time-offlight(Bρ-△E-TOF) method at HFRS for high-precision in-flight particle identification of radioactive isotope beams on an event-by-event basis. Most importantly, the detector can be utilized for in-ring TOF and position measurements,beam-line TOF measurements at two achromatic foci, and position measurements at a dispersive focus of HFRS, thus making it possible to use two complementary mass measurement methods [isochronous mass spectrometry at the storage ring SRing and magnetic-rigidity–time-of-flight(Bρ-TOF) at the beam-line HFRS] in one single experimental run.     

Corrosion behaviour of Al1.3CrFeNi chemically complex alloy

In this study, corrosion behaviour of double-phase Al_1.3CrFeNi chemically complex alloy was investigated, including hot corrosion and electrochemical corrosion. Hot corrosion behaviour of Al_1.3CrFeNi alloy was explored in molten 75 wt-% Na₂SO₄?+?25 wt-% NaCl salt. The result revealed that the corrosion kinetic curve of Al_1.3CrFeNi alloy followed the exponential rate rule through mass loss measurement. In addition, it prevented that the formed corrosion layer had obvious stratification including external granular Al₂O₃ and inner porous Cr₂O₃ when corrosion time was up to 100?h. Besides, it should be noted that the Al_1.3CrFeNi alloy was sensitive to the molten salt containing chlorine, which makes the alloy surface leave voids and bring about acceleration of corrosion. Meanwhile, electrochemical corrosion resistance of Al_1.3CrFeNi alloy in NaCl solution with different concentrations (0.6, 1.0 and 2.0?mol?L^?1) was investigated at room temperature. The results revealed that Al_1.3CrFeNi alloy showed superior corrosion resistance in NaCl solution due to the existence of Al and Cr which aid the formation of protective oxide layer.     

鞍钢提高高炉利用系数生产管理实践

针对鞍钢股份有限公司炼铁总厂高炉群平均利用系数低的问题,从原料条件、操作炉型和操作管理三个方面进行了原因分析,通过采取原燃料指标量化管理、高炉炉型诊断管理、操作参数科学管理等措施,克服了原燃料结构变化等不利因素,提高了高炉群平均利用系数,实现了高炉长周期稳定顺行。     

鞍钢4号高炉炉墙结厚原因及解决措施

鞍钢4号高炉停炉大修更换炉缸耐材后,高炉出现炉墙结厚现象。通过对炉墙结厚原因进行分析,采取了加强原料质量管理、降低冷却强度和调整装料制度等措施,炉墙结厚得到有效处理,高炉炉况恢复正常。     

复杂金精矿浸铜渣预处理工艺

对复杂金精矿浸铜渣硫酸和氟化氢铵预处理工艺进行研究,考察了硫酸与氟化氢铵摩尔浓度比值(R_(S/A))、摩尔浓度、反应液固比、反应时间、反应温度、搅拌速度对金银提取率的影响。结果表明,R_(S/A)和硫酸与氟化氢铵摩尔浓度是影响金银提取率的关键因素,在R_(S/A)=1/1,其摩尔浓度值升高,金、银的提取率可以得到显著提高。浸铜渣经预处理后,包裹物遭到破坏,出现蜂窝状孔隙,硅含量由原来的33.28%降低到5.49%。最佳预处理条件:R_(S/A)=1/1、摩尔浓度值1.5mol/L、反应液固比5∶1、反应时间2h、反应温度298K、搅拌速度250r/min。氰化条件:反应液固比4∶1、pH=10.5、氰化钠浓度4‰、搅拌速度300r/min、反应时间72h、反应温度298 K,此条件下,金、银的提取率分别为98.20%、95.77%,氰化残渣中金、银含量分别小于1.3g/t、50g/t。     

某铀尾矿库周边地表水中铀和钾分布特征与评价

选取我国南方某铀尾矿库周边地表水为研究对象,分析周边地表水中的铀和钾的含量及其与水化学参数pH、Eh和电导率之间的关系,研究铀和钾的污染特征与影响因素,最后进行单因子污染评价。结果表明,尾矿库本身放射性水平高,采样点铀和钾的平均含量分别是江西省背景值的14.68倍和2.02倍。皮尔逊系数计算结果说明铀和钾具有相同的来源和迁移特征,单因子评价结果显示污染最严重位置处于尾矿库坝体底部和水处理厂出口。但所有样品铀含量均未超出《铀矿冶辐射防护和环境保护规定》限值,除最近采样点外,周边地表水其他采样点铀含量均符合国际饮用水标准。     

基于AVIRIS高光谱数据的海表甲烷异常识别

研究海洋表面烃类富集状况在监测海洋环境和探测海底油气资源中具有重要意义,海表渗漏烃中,甲烷是气态烃中最具代表性的组分。为了精准识别海表甲烷异常,研究设计了相应光谱实验,以海水为背景测定甲烷光谱反射率,基于实测数据分析甲烷的光谱特征,运用比值导数光谱法削弱海水背景组分的光谱干扰,提取出甲烷光谱吸收特征波段。研究发现甲烷在1 642—1 672 nm和2 169—2 378 nm波长范围存在光谱吸收,通过比值导数处理后显著增强了其中1 642—1 672 nm和2 169—2 208 nm区间的甲烷吸收特征,在Rebecca等提出的CH4I甲烷反演指数的基础上加入比值导数参数,建立了基于AVIRIS数据的海表甲烷含量指数MI,与甲烷含量的相关系数R2=0.994 2,将其应用于美国加利福利亚州圣芭芭拉海峡Coal Oil Point(COP)烃渗漏区甲烷异常识别,并与CH4I指数和Bradley等提出的AVIRIS CH4指数ζ(L2298/L2058)进行反演效果对比。结果表明：运用MI指数可以有效识别海表甲烷浓度异常,与ζ、CH4I指数反演结果相比,MI指示的甲烷浓度异常分布与ζ指数反...     

高洁净度钢轨钢的夹杂物控制技术

针对国内生产350 km/h高洁净度钢轨存在非金属夹杂物控制的核心问题,开展了相关研究.通过采用适宜的钢包底部吹氩模式和钢包渣组成,显著提高了钢中非金属夹杂物的去除率,T[O]去除率提高近40%;对硫化物夹杂的变性处理有效地控制了钢轨钢中夹杂组成和形态.这些技术在350 km/h高洁净度钢轨钢生产中的应用,不仅使钢轨的T[O]降到10.17×10-6,而且A类和B、C、D类非金属夹杂物评级分别≤2.0级和1.0级,实现了350km/h高洁净度钢轨钢的批量生产.     

草酸亚锡催化合成PTT的研究

采用对苯二甲酸(PTA)和1,3-丙二醇(1,3-PDO)为原料,以自制的草酸亚锡为催化剂经酯化、缩聚,制得聚对苯二甲酸丙二醇酯(PTT)。探讨了反应条件对合成反应的影响。结果表明:草酸亚锡的催化活性优于丁基锡酸和辛酸亚锡。1,3-PDO／PTA的摩尔比为1．5／1、草酸亚锡用量为5×10-4mol／mol(相对PTA),酯化反应温度260℃,反应时间2 h;缩聚反应温度260℃,反应时间2 h,可制得PTT,其特性粘数为0．8950dL／g,端羧基含量为15 mol／t。