基于密度泛函理论的铁含量对含铁闪锌矿浮选影响的研究

采用密度泛函理论, 研究了铁含量对闪锌矿(110)表面的表面弛豫、电子性质及铜活化的影响。研究结果表明, 对于低铁含量的闪锌矿, 闪锌矿(110)表面的锌原子和铁原子向表面内部的弛豫均变小, 减小了空间位阻; 电子态密度及能带结构表明, 铁电子活性较强, 且无自旋极化, 即低铁有利于闪锌矿浮选。对于高铁含量的闪锌矿, 其表面的铁原子向内部弛豫较大, 增大了空间位阻; 电子态密度及能带结构表明铁的活性不高, 出现自旋极化, 不利于浮选。而闪锌矿(110)表面上铁不易被铜替换, 且铁的含量越多越不利于铜的替换。该研究从原子层面上解释了铁含量对闪锌矿(110)表面性质和铜活化的影响, 为含铁闪锌矿的浮选提供理论指导。     

超净高纯盐酸生产工艺的研究

本文描述了一种电子纯盐酸的制备方法 ,包括氯化氢的蒸发、气体净化、高纯水吸收以及最终提纯等步骤 ,并对按此工艺生产的盐酸产品采用ICP MS和离子交换色谱进行了分析 ,实验证明此工艺能够有效去除工业盐酸中Fe、Cu、Pb、As等杂质离子。     

高倍率低温可膨胀石墨制备的研究

本文以HNO3/HBrO3/KMnO4为氧化插层体系制备低温可膨胀石墨,研究了制备低温可膨胀石墨的最佳条件和物料配比,讨论了插层试剂对起始膨胀温度的影响,提出了氧化插层的机理.研究表明:制备低温可膨胀石墨的反应温度为室温(25 ℃);反应时间40 min;石墨、硝酸、溴酸钠、高锰酸钾的最佳质量比为1∶[KG-·2]3∶[KG-·2]0.1∶[KG-·2]0.07,由此方法制得的可膨胀石墨起始膨胀温度为130 ℃,600 ℃时膨胀容积为350 mL/g.     

BOTA型氰化物浓度在线分析仪的升级及工业应用

氰化物浓度是氰化浸金工艺的重要参数,通过氰化物浓度在线检测控制可以有效减少氰化物消耗。介绍了BOTA型氰化物浓度在线分析仪的技术升级,由光度滴定替代电位滴定,提高了仪器测量性能及可靠性。升级后的BOTA-Ⅱ型氰化物浓度在线分析仪在排山楼金矿进行了工业应用,在氰化钠和某低氰药剂的浸出流程中均能实现氰化物浓度的在线测量,测量精度及可靠性满足要求,为企业带来了显著的经济效益。     

Synergistic effects of advanced oxidization reactions in a combination of TiO2 photocatalysis for hydrogen production and wastewater treatment applications

In this paper, the synergistic effects of advanced oxidization reactions in a combination of TiO₂ photocatalysis are comparatively investigated for hydrogen production and wastewater treatment applications. An experimental study is conducted with a photoelectrochemical reactor under a UV-light source. TiO₂ is selected as the photocatalyst due to the high corrosion resistant nature and ability to form hydroxyl radicals with the interaction with photons. The synergetic effects of advanced oxidization processes (AOPs) such as Fenton, Fenton-like, photocatalysis (TiO₂/UV) and UV photolysis (H₂O₂/UV) are investigated individually and in a combination of each other. The Fenton type reagent in the reactor is formed by anodic sacrificial of stainless-steel electrode with the presence of H₂O₂. The influences of various parameters, including pH level, type of the electrode and electrolyte and the UV light, on the performance of the combined system are also investigated experimentally. The highest chemical oxygen demand (COD) removal efficiency is observed as 97.9% for the experimental condition which combines UV/TiO₂, UV/H₂O₂ and photo-electro Fenton type processes. The maximum hydrogen production rate from the photoelectrolysis of wastewater is obtained as 7.0 mg/Wh for the experimental condition which has the highest rate of photo-electro Fenton type processes. The average enhancement with the presence of UV light on hydrogen production rates and COD removal efficiencies are further calculated to be 3% and 20%, respectively.     

Carbon nanorod supported metal alloy nanocubes using polydopamine as location reagent for water splitting

Transition metal catalysts were supposed to be the most likely substitute for commercial noble metal catalysts, and the development of highly active and long-term catalyst for water splitting are the future trend. Herein, Ni rectangular nitrogen doped carbon nanorods@Fe–Co nanocubes (Ni-CNRs@Fe–Co cubes) were fabricated via a facile template-free method. This simple strategy not only realizes the structure tailoring, but also achieves high-quality nitrogen-doping. Specifically, nickel dimethylglyoxime [Ni(dmg)₂] with rectangular rodlike structure was firstly synthesized by solution method, then metal-organic frameworks Fe–Co nanocube with different contents were loaded on rectangular carbon nanorods with polydopamine as the locating and the connecting agent, and finally Ni-CNRs@xFe-Co cubes were obtained by a one-step calcination. A series of electrochemical tests were researched on materials with different metal contents in the 1 M KOH solution. The Ni-CNRs@Fe–Co cubes show excellent electrocatalytic activity in the hydrogen evolution reaction (HER) and the oxygen evolution reaction (OER). For HER and OER, the Tafel slopes were 83.3 mV dec⁻¹ and 71 mV dec⁻¹, the onset potential were −167 mV and 1.62 V, and reached the current densities of 10 mA cm⁻², the overpotential just needed 196 mV and 433 mV, respectively. This novel synthetic strategy will provide a template-free way for cheap electrocatalysts of non-precious metal for OER and HER.     

某铜矿浮选药剂用量优化及技术应用探讨

湖北某铜矿浮选在常规加药条件下，前两槽不能有效形成泡沫层，浮选液面经常出现“翻花”现象，以致选矿指标波动大，起泡剂用量大幅上升，因此开展了浮选试验研究。试验结果表明，在总药量不变的情况下，适当降低粗选捕收剂用量，使有用矿物有序上浮，有效改善了浮选泡沫层的稳定性。在生产现场应用后，浮选现场泡沫稳定，层次感分明，彻底解决了浮选前两槽不起泡、翻花等问题，选铜回收率提高0.69%，起泡剂单耗降低18g/t，取得较好的应用效果。     

羊绒织物前处理工艺研究

羊绒织物因其优异的服用性能,越来越受欢迎。但是,现有的羊绒织物前处理工艺与高温沸染工艺分别存在着污染问题和高能耗问题,不符合当今绿色发展的主题。所以,为了解决该问题,实验采用生化试剂610替代二氯异氰脲酸。实验通过对比610与DCCA各浓度下处理的羊绒纱线的力学性能、染色性能,并创新的从染色动力学方面对其进行深入探讨,选出较优的610浓度。最终,确定选择1%(owf)的610代替DCCA并且与0.5%(owf)的碱性蛋白酶复合处理羊绒纱线。其实验结果为:强力损失率为7.51%,羊绒鳞片层基本结构保留,固色率为95.77%,上染速率常数为0.05,t1/2为13.87min。     

空气中甲醛含量测试在线监测仪验证

本文依据国标GB/T 18204.26-2000采用酚试剂法测空气中甲醛含量,通过对相同的样品测试,比较采用此方法与市售甲醛在线检测仪AL4021所得数据,验证在线监测仪可靠性。AL4021在高中低(1.5 mg/m3、0.1mg/m3、0.01mg/m3)三个浓度点的测试结果偏差分别为5.47%、14.05%、-3.14%,不超过15%,表明其数据可靠性高,此设备在其标称应用范围内可用。     

微生物诱导碳酸钙沉积加固有机质黏土的试验研究

利用尿素水解菌ATCC 11859,开展了不同胶结液浓度下MICP压力灌浆加固有机质黏土的研究试验。通过试验前后试样的无侧限抗压强度、CaCO_3含量、渗透系数、有机质含量以及灌浆过程中流出液Ca~(2+)与NH_4~+浓度的变化,综合评价了MICP压力灌浆加固有机质黏土的效果。结果表明:MICP压力灌浆加固有机质黏土是有效的,处理后试样有机质含量可降低1%～4%,无侧限抗压强度提高可达370%,渗透系数可降低约1个数量级;在本试验的菌液活性(即每分钟水解尿素的量为9.68毫摩尔每升)及浓度(约108 cell/mL)下,胶结液浓度对处理效果有明显影响,提高0.25M胶结液中的urea浓度,可显著提高处理后土体的无侧限抗压强度。