Optimization of efficient stable reagent of alkaline thiourea solution for gold leaching

1　INTRODUCTIONThiourea ,asanontoxic goldleachingreagentsubstitutingcyanide ,hasattractedtheinterestofmanyresearchersallovertheworldsincethedissolu tionofgoldinthioureasolutionwasfirstreportedin194 1,andaseriesofstudiesonthetheoryandtech nologyforleachinggoldbythioureahavebeencon ducted[1 3] .Mostreportson golddissolutioninthioureasolutionwereconcernedwithacidicmedia .Itwasdifficultforgoldtodissolveinalkalinesolutionbecauseofthepassivationofelementsulfurproducedbytheirreversibledecompositi…     

钙基固硫剂脱硫特性优化组合的多元模型

运用优化组合的多元建模方法，研究了钙基固硫剂化学组成与脱硫效果之间的数量关系，建立了钙基固硫剂化学成分与其脱硫率关系的优化组合的多元模型，实际运行表明，该模型比原来逐步回归法建立的多元模型准确率提高了0．42％，避免和克服了实际应用中的障碍和困难，方便了钙基固硫剂化学性能的分析及钙基固硫剂种类的选择。     

无吡啶,无甲醇卡尔费休试剂的应用

对传统卡尔费休试剂的不足进行了分析 ,提出了一种用有机胺代替吡啶 ,用多元醇衍生物代替甲醇的无吡啶、无甲醇、高效低毒、性能稳定、应用范围广泛、克服了传统卡尔费休试剂无法测定含羰基化合物样品中微量水弊端的新型卡尔费休试剂。经与英国BDH公司、北京石油科学研究院和山东淄博无线电一厂生产的市售卡尔费休试剂的对比分析和工厂现场试验证明本试剂可完全替代传统和进口卡尔费休试剂对石油产品、化工产品及含有羰基化合物样品中的微量水分分析。分析误差符合GB6 0 6 77规定的范围     

难选氧化铜矿的浮选试验研究

针对某难选氧化铜矿石氧化率和结合率高，原矿品位低，脉石矿以钙镁含量高的碳酸盐碱性为主的特点，考查了不同的捕收剂回收氧化铜的效果，表明采用提高磨矿细度。组合捕收剂，深化活度，强化连生体和细粒铜矿物的有效选别，在保证铜精矿品位波动不大的情况下，提高选矿回收率7．82％，选矿工艺流程简单易行，具有应用价值。     

Fenton氧化处理垃圾渗滤液生化工艺出水的影响因素研究

采用Fenton试剂处理生化处理后的垃圾渗滤液,探讨了pH、Fe2+、H2O2、反应时间等对CODCr去除效果的影响.结果表明,Fenton氧化法对垃圾渗滤液CODCr去除有较好的效果.Fen ton氧化法的最佳操作条件:pH=7,H2O2投加次数为1,FeSO4·7H2O的投加量为0.1mol/L,H2O2/FeSO4·7H2O投加比为4∶1,反应时间为210min,反应温度为30℃.     

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。