硫酸铵在孔雀石的黄药直接浮选中的相转移化机理研究

以铵盐－孔雀石浮选体系的溶液化学研究为基础，通过测试分析和计算，探讨和论证了无机铵盐在孔雀石浮选中的相转移催化理论，描述了假想的相转移催化机理图。     

硫酸铵在孔雀石的黄药直接浮选中的相转移催化机理研究

以铵盐－孔雀石浮选体系的溶液化学研究为基础，通过测试分析和计算，探讨和论证了无机铵盐在孔雀石浮选中的相转移催化理论，描述了假想的相转移催化机理图     

矿浆溶液体系对孔雀石浮选的影响

纯矿物浮选试验结果表明：在直接浮选及硫化浮选中，硫酸铵均可成功地用作孔雀石浮选的活化剂。从浮选溶液化学角度研究了铵盐在氧化铜矿浮选中的机理。     

硫酸铵对黄药在孔雀石表现吸附的促进作用

吸附试验结果表明：硫酸铵活化孔雀石浮选，是通过提高吸附黄药能力来实现的。在孔雀石－黄药浮选体系中加入硫酸铵，可大幅度提高黄药的吸附量和吸附速度，饱和吸附量提高了１倍，吸附速度常数由０．５６提高到１０．１６，可见硫酸铵对黄药在矿物表面的吸附起了“促进吸附”作用。     

硫酸铵对黄药在孔雀石表面吸附的促进作用

吸附试验结果表明：硫酸铵活化孔雀石浮选，是通过提高吸附黄药能力来实现的在孔雀石－黄药浮选体系中加入硫酸铵，可大幅度提高黄药的吸附量和吸附速度，饱和吸附量提高了１倍，吸附速度常数由０５６提高到１０１６，可见硫酸铵对黄药在矿物表面的吸附起了“促进吸附”作用     

铵盐对红曲黄色素、红色素及桔霉素代谢形成的影响

研究了氯化铵、乙酸铵、硫酸铵、磷酸二氢铵、柠檬酸三铵和硝酸铵等6种作为无机氮源的铵盐对红曲霉突变菌株MYM代谢形成红曲色素和桔霉素的影响.结果表明,无机铵盐对红曲黄色素的代谢形成影响不明显,但是对红曲红色素和桔霉素的代谢形成影响比较大,从而显著影响发酵液的黄色素色调.当以硝酸铵为氮源时,因为铵盐的消耗而导致的高pH值发酵环境能明显抑制桔霉素的代谢形成,但是也能提高胞外黄色素和胞外红色素的得率.当铵盐消耗使发酵液pH值维持在3~5时,比较有利于桔霉素的代谢形成.然而,当铵盐消耗使发酵液pH值低于3时能明显抑制桔霉素的代谢形成.     

不同铵盐体系中金属锰在水中的锈蚀速率

研究了不同铵盐介质中金属锰在水中的蚀速率，考察了铵盐种类，铵盐逍度及温度等参数对金属锰锈蚀速率的影响。研究结果表明，当水溶液中没有铵盐时，金属锰几乎不与水发生反应；而当存在铵盐时，锰的锈蚀速率大大增加，随着铵盐浓度的增加，锰粉的锈蚀速率明显加快；不同的铵盐对锰粉锈蚀速率的影响不同，在所试验的几种铵盐中，以乙酸铵锈蚀的速度最大；在不同铵盐介质中，温度对反应速率的影响具有不同的规律性，体现在：乙酸铵介质中，随着温度的升高，反应速率下降，硫酸铵介质中，当温度为40－80℃时，以70℃时的反应速率最大，而氯化铵介质中，在30－70℃时，以50℃时的反应速率最大。     

氧化铜矿浮选基础理论研究新进展

氧化铜矿作为铜冶炼的重要原料,其高效选别一直受到业内学者的关注.随着硫化铜矿资源逐渐枯竭,氧化铜矿的开发利用则变得尤为重要.常用的氧化铜矿物回收方法有直接浮选法、硫化浮选法、选冶联合等方法,然而,采用这些方法回收不同类型氧化铜矿物暴露出的捕收剂捕收能力不强、硫化效率不高、硫化机理不统一等问题,在一定程度上限制了氧化铜矿浮选的发展.近年来,随着新药剂研发、表面测试技术以及量子化学计算等的快速发展,在现有理论基础上创新了多种有效的氧化铜矿浮选新方法及新理论,如孔雀石的层间硫化理论打破了硫化反应的传统认知,将硫化过程由界面拓展至矿物内部,认为S^2-可深入到孔雀石体相形成Cu—S—Cu的吸附构型,使孔雀石结构更加稳定;硅孔雀石共轭活化理论通过溶液中添加的磷酸铵和硫化钠发生水解反应,构建的多组共轭酸碱对起到的缓冲作用为硅孔雀石表面硫化铜晶体的生长创造了良好的环境,从而促进了硅孔雀石的浮选回收.新方法及新理论的出现对完善现有氧化铜矿浮选理论体系具有重要意义,也为生产实践提供了新思路.通过对近些年氧化铜矿浮选相关研究成果的梳理,着重论述了氧化铜矿基础理论研究的新进展.     

加氢空冷系统氯化铵沉积多场耦合模型及数值模拟

通过分析铵盐在加氢空冷管束内的结晶沉积过程,构建流动场、温度场和浓度场耦合作用下的铵盐沉积计算模型,并结合有限元法对氯化铵盐的流动沉积过程进行了数值模拟。研究结果表明:铵盐流动沉积是一个多物理场耦合的过程,典型工况下加氢空冷系统中氯化铵最大沉积量位于距管束入口0.98 m处。该数值模拟方法可有效预测实际空冷器管束入口铵盐沉积失效危险区域。     

有机螯合剂活化硅孔雀石浮选特性研究

用浮选试验和现代测试技术,研究了有机螯合剂对硅孔雀石的活化作用。结果表明,一些亲铜有机螯合剂能有效活化硅孔雀石的浮选。活化效果与螯合剂化学活性和矿物溶解性能有关,活化机理主要为有机螯合剂的强化学活性明显提高了捕收剂的吸附量。     

Dissolution kinetics of malachite in ammonia/ammonium sulphate solution

The dissolution kinetics of malachite was investigated in ammonia/ammonium sulphate solution. The effects of ammonia and ammonium sulphate concentration, pH, leaching time, reaction temperature, and particle size were determined. The results show that the optimum leaching conditions for malachite ore with a copper extraction more than 96.8% are ammonia/ammonium concentration 3.0 mol/L NH₄OH + 1.5 mol/L (NH₄)₂SO₄, liquid-to-solid ratio 25:1 mL/g, leaching time 120 min, stirring speed 500 r/min, reaction temperature 25 °C and particle size finer than 0.045 mm. The dissolution process of malachite with an activation energy of 26.75 kJ/mol is controlled by the interface transfer and diffusion across the product layer. A semi-empirical rate equation is obtained to describe the leaching process and the reaction orders with respect to concentration of ammonia and ammonium sulphate are 2.983 0 and 0.941 1, respectively.     

Flotation and adsorption of quaternary ammonium salts collectors on kaolinite of different particle size

The flotation behaviors of decyltrimethylammonium (103C), dodecyltrimethylammonium chloride (DTAC), tetradecyltrimethylammonium chloride (TTAC) and cetyltrimethylammonium chloride (CTAC) on kaolinite of different particle size fraction were studied. The adsorbed amount and adsorption isotherms of collectors on kaolinite were determined for painstaking investigation into the adsorption of quaternary amines at kaolinite–water interface by ultraviolet spectrophotometer methods. The flotation results show that the flotation recovery of kaolinite of different particle fraction increases with an increase in pH when 103C, DTAC, TTAC and CTAC are used as collectors. As the concentration of collectors increases, the flotation recovery increases. Particle size of kaolinite has a strong effect on flotation. The flotation recovery of fine kaolinite decreases with the carbon chain of quaternary ammonium salts collectors increasing, while coarse kaolinite is on the contrary. The adsorbed amount tests and adsorption isotherms show that adsorbed amount increases when the particle size of kaolinite increases or when the carbon chain length of quaternary ammonium salts increases. Within the range of flotation collector concentration, the longer the hydrocarbon chain, the more probable to be absolutely adsorbed by fine kaolinite particles and then the lower the collector concentration in the bulk, which leds to lower flotation recovery.     

Effect of quaternary ammonium salts on flotation behavior of aluminosilicate minerals

The electrokinetic properties and flotation of diaspore,kaolinite,pyrophyllite and illite with quaternary ammonium salts collectors were studied.The results of flotation tests show that the collecting ability of quaternary ammonium salts for the four minerals is in the order(from strong to weak)of octadecyl dimethyl benzyl ammonium chloride(ODBA),cetyl trimethyl ammonium bromide(CTAB),dodecyl trimethyl ammonium chloride(DTAC).Under the condition of alkalescence,it is possible to separate the diaspore from the silicate minerals such as kaolinite,illite and pyrophyllite using quaternary ammonium salts as collector.Isoelectric points(IEP)of diaspore,kaolinite,pyrophyllite and illite are pH=6.0,3.4,2.3 and 3.2,respectively.Quaternary ammonium salts can change ζ-potential of the aluminosilicate minerals obviously.The flotation mechanisms were explained by ζ-potential and Fourier transform infrared spectrum(FT-IR)measurements.The results demonstrate that only electrostatic interaction takes place between aluminosilicate     

Flotation of copper oxide minerals: A reviewOA

Copper oxide minerals are important copper resources, which include malachite, azurite, chrysocolla,cuprite, etc. Flotation is the most widely used method for the enrichment of copper oxide minerals in the mineral processing industry. In this paper, the surface properties of copper oxide minerals and their effects on the mineral flotation behavior are systematically summarized. The flotation methods of copper oxide minerals and the interaction mechanism with reagents are reviewed in detail. Flot...     

季铵盐类聚合物增强纳米抗菌材料性能的研究进展

季铵盐类聚合物由于具有正电荷,可以通过静电作用吸附于细菌细胞膜,破坏细菌细胞膜结构,因而在抗菌方面具有独特应用。近年来,将季铵盐类聚合物与纳米抗菌材料结合以提高材料的抗菌性能取得一系列的研究成果。该文综述了近年来季铵盐类聚合物修饰无机纳米抗菌材料后在增强材料分散性、稳定性、抗菌活性以及降低毒性方面的研究进展,举例说明了常见的季铵盐类聚合物修饰前后对无机纳米材料抗菌活性的影响,并分析了作用机理。最后,对季铵盐类聚合物增强纳米抗菌材料性能的应用及未来发展方向进行了展望。     

Adsorption behavior and mechanism of copper ions in the sulfidization flotation of malachite

Malachite is one of the main minerals used for the industrial enrichment and recovery of copper oxide resources, and copper ions are unavoidable metal ions in the flotation pulp. The microflotation, contact angle, and adsorption experiments indicated that pretreatment with an appropriate concentration of copper ions could improve the malachite recovery, and the addition of excess copper ions reduced the hydrophobicity of the malachite surface. The results of zeta potential tests indicated that sodium sulfide and butyl xanthate were also adsorbed on the surface of malachite pretreated with copper ions. X-ray photoelectron spectroscopy (XPS) results indicated that —Cu—O and —Cu—OH bonds were formed on the surface of the samples. After pretreatment with an appropriate concentration of copper ions, the number of —OH groups on the mineral surface decreased, whereas the number of Cu—S groups on the mineral surface increased, which was conducive to the sulfidization of malachite. After adding a high concentration of copper ions, the —OH groups on the mineral surface increased, whereas the number of Cu—S groups decreased, which had an adverse effect on the sulfidization flotation of malachite. Time-of-flight secondary ion mass spectrometry showed that pretreatment with copper ions resulted in a thicker sulfidization layer on the mineral surface.     

季铵盐在土壤中的吸附行为

通过静态吸附实验研究了土壤对季铵盐的吸附行为,进行吸附等温线的测定并考察吸附时间、吸附温度、土壤有机质含量对吸附效率的影响.结果表明,3种不同土样对季铵盐的吸附等温线均较好地符合Langmuir吸附模式,并且计算得到各方程组成的参数项数值都能较好地反映土壤的吸附特性.季铵盐在土壤中的吸附过程很快,振荡30min即已达到最大吸附率的90%,1h就达到了吸附平衡.温度的升高不利于季铵盐在土壤中的吸附,温度从25℃升高到45℃,季铵盐的饱和吸附量从32.0mg.g-1降低到29.9 mg.g-1,吸附量与土壤有机质含量具有线性关系,随着有机质含量的增大而增大.