Reaction of sodium perborate with a chlorinated cyclic hindered amine (TMP-Cl): I. Quantitative evaluation of active oxygen species in fabric bleaching

The reaction of N-chloro-4-hydroxy-2,2,6,6-tetramethylpiperidine (TMP-Cl) with sodium perborate (PB) was investigated with special reference to the generation of singlet oxygen and the possible application to a new oxidative bleaching process. Generation of the singlet oxygen (¹O₂), the hydroxyl radical (HO·) and superoxide anion radical (O₂·⁻) in the PB/TMP-Cl mixed solution was confirmed by the trapping reagent method. From the results of another experiment, in which the bleaching abilities of each active oxygen species were confirmed, the main active oxygen species contributing to the bleaching of purpurogallin, the skeleton of black tea pigment, in the PB/TMP-Cl system was concluded to be¹O₂.     

激发剂对钢渣-矿粉胶凝材料力学性能的影响及机理分析

研究了氢氧化钙、石膏、硫酸钠三种激发剂对钢渣-矿粉胶凝材料力学性能的影响,并结合XRD图谱分析了激发剂对钢渣-矿粉胶凝材料水化产物的影响机理。试验结果表明,三类激发剂中,硫酸钠能更好的激发钢渣-矿粉的活性,当硫酸钠的掺量为1.5%时,3d强度为18.0MPa,7d强度达到22.5MPa,28d强度达到25.8 MPa。XRD分析表明,掺入硫酸钠后,钢渣-矿粉胶凝材料的水化产物主要为C-S-H凝胶、棒柱状AFt晶体及少量的Ca(OH)2晶体,激发剂掺量的不同,水化产物数量不同,合适掺量的激发剂有助于激发体系的水化活性,提高体系的力学性能。     

铁闪锌矿的选矿研究概况

介绍了铁闪锌矿在我国的分布特点和铁闪锌矿含铁量与其可选性的关系。从浮选流程结构、铁闪锌矿的粒度、铁闪锌矿的活化、石灰和pH值、铁闪锌矿的捕收剂以及磁黄铁矿的抑制等各主要方面对铁闪锌矿选矿技术的研究和实践进行了较全面的总结归纳和分析,以期对铁闪锌矿选矿的更深入研究和铁闪锌矿及其伴生元素的更高效回收利用有所裨益。     

我国家用洗涤用品的发展趋势

洗涤剂是人们日常生活中的必需品。文章通过对各种洗涤剂用品的分析报道，指出了洗涤剂在我国的发展趋势。     

高强度矿渣胶凝材料抗压强度影响因素的研究

研究了以矿渣、石膏、石灰为主要原料的矿渣胶凝材料在蒸养下抗压强度的影响因素,并通过正交实验方法对原料的配合比、蒸养条件等进行了优选。结果表明:在蒸养温度80℃时,掺入8%的石膏、14%的石灰复合激发剂能较好激发矿渣的活性,胶凝材料28d的抗压强度达到85MPa。     

转炉钢渣的胶凝性能和活性激发

分析了转炉钢渣的矿物组成和胶凝性能,研究了Na_2SO_4、CaCl_2、NaCl和海水对钢渣浆体和钢渣水泥浆体强度的影响。结果表明,钢渣粉3d的水化放热量仅为P·O 42.5水泥的7.5%,钢渣浆体7d和90d抗压强度只有0MPa和15.1MPa,所以钢渣粉自身水化能力很低,胶凝性很差。Na2SO_4和CaCl_2对于钢渣浆体有一定的激发效果,掺0.9%Na_2SO_4时激发效果最好,浆体3d和90d抗压强度比不掺激发剂的空白组提高了19.1%和8.2%。对于钢渣水泥浆体,掺1.2%CaCl_2的浆体强度最高,浆体3d和90d抗压强度分别比空白组提高了53.6%和16.9%。NaCl和海水对钢渣浆体和钢渣水泥浆体3d强度有明显的激发作用,但会使90d强度出现较明显的倒缩。     

Paste backfill of high-sulphide mill tailings using alkali-activated blast furnace slag: Effect of activator nature,concentration and slag properties

The effect of activator type, concentration and slag composition on the strength and stability properties of paste backfill (CPB) of high-sulphide tailings using alkali-activated slag (AAS) as binder (7 wt.%) were investigated in this study. Acidic and neutral (AS–NS) slags were activated with liquid sodium silicate (LSS) and sodium hydroxide (SH) at 6–10 wt.% concentrations. Ordinary Portland cement (OPC) results were used for comparison. The strength development was found to remarkably improve with increasing the concentration from 6 to 8 wt.%. Further increase in concentration did not enhance the strength. SH was determined to produce higher early-age strength whilst LSS produced higher long-term strengths as an indication of slag selectivity for activators. More extensive gypsum formation was observed at lower concentrations in SEM/EDS studies. An increase in Na₂O concentration raised the activator consumption. High concentrations also led to poorly crystallized C–S–H gel, loose structure and drying shrinkage cracks especially in NS–SH samples. A reduction in total porosity up to 20% was obtained in AAS samples compared to OPC. Amorphous structure, chemical modulus ratio and/or basicity index (BI) values were seen to control the pozzolanic reactivity, and therefore, the alkali-activation and hardening process.     

激发剂对掺工业废渣胶凝材料路用性能的影响

试验采用硅酸盐水泥熟料与不同的工业废渣(钢渣、矿渣、磷渣、液态渣和铜渣)配制成各种复合胶凝材料，研究了不同种类的工业废渣、不同的熟料掺量、特别是不同钢渣和矿渣之比的复合废渣胶凝材料的物理力学性能，收缩和耐磨等路用性能，同时还研究了不同激发剂(水玻璃，明矾，元明粉Na2SO4，三乙醇胺TEA和明矾石等)对掺工业废渣的胶凝材料路用性能影响，并结合微观结构，对其机理进行了分析。     

某低品位锂辉石矿石浮选试验研究

某低品位锂辉石矿石含Li_2O仅约为0.97%,远低于当前工业生产中锂辉石选矿原矿的平均品位,且该矿石中矿物组成复杂,含锂矿物较多,嵌布关系密切,代换作用强烈,作为主要回收矿物的锂辉石中Li_2O含量最高仅为5.82%,以上都成为了高效利用该低品位锂辉石矿石的制约因素。为了解决上述问题,同时为处理低品位锂辉石矿石提供可能的技术参考,针对该矿石开展了详细试验研究。采用新型、高效、选择性好的含锂矿物捕收剂BK317和活化剂TC,在磨矿细度-74μm占75%的情况下,经一次粗选三次精选一次扫选、中矿顺序返回闭路流程,最终获得含Li_2O 4.46%、回收率80.40%的锂辉石精矿。     

黄磷渣充填胶凝材料激发剂的选择与优化

根据黄磷渣的物理、化学和热力学的特点及其活性激发原则,以黄磷渣-磷石膏为研究对象,通过大量室内试验,以不同龄期的充填体抗压强度为指标,研究了不同激发剂种类及掺量对黄磷渣充填胶凝材料的激发效果,分析了黄磷渣在激发剂作用下的水化反应机理。试验结果表明,黄磷渣的活性在NaOH和CaO激发作用下均有较大提高,NaOH和CaO的最佳掺量分别为5%和8%。黄磷渣的水化反应产物存在水化硅酸钙,此外,磷石膏中的硫酸盐在激发黄磷渣活性中也起到了一定作用。