A simple route for the synthesis of symmetrical thiourea derivatives and amidinium cations by reaction between isocyanides,amines and carbon disulfide

Reaction between primary amines and CS₂ promoted by alkyl isocyanides in ethanol as solvent provides a simple and efficient route for the synthesis of symmetrical thiourea derivatives. The reaction of secondary amines with carbon disulfide and alkyl isocyanides afforded new amidinium cations in good yields.     

Effect of N-substituents on performance of thiourea collectors by density functional theory calculations

Using density functional methods, some properties were studied such as the energies and compositions of frontier molecular orbitals and the atomic charges, which are related to the reactive behavior of thioureas containing different N-substituent groupings. The calculation results indicate that the N-substituent groupings have significant effect on the flotation performance of thiourea collectors. The order of electron-donating ability is N-propyl-N′-benzyl-thiourea (PBZYTU)＞N-propyl-N′-ethyl-thiourea (PETU) ＞N-propyl-N′-allyl-thiourea (PALTU)＞＞ N-propyl-N′-acetyl-thiourea (PACTU) ＞N-propyl-N′-ethoxycarbonyl- thiourea (PECTU) ＞N-propyl-N′-benzoyl-thiourea (PBZOYTU), and the order of feedback-electron-accepting ability is PBZOYTU＞PACTU＞PECTU＞＞ PALTU＞PETU＞PBZYTU. This implies that PBZOYTU, PACTU or PECTU can react with copper atoms having (t2g)6(eg)3Cu(II) or t6e4Cu(I) configuration on the surfaces of copper sulfide minerals through normal covalent bond and back donation covalent bond, and exhibit excellently collecting performance for copper sulfide minerals. These are consistent with the experimental data reported in the literatures.     

硫脲改性Fe_3O_4/壳聚糖微球对Hg~(2+)的吸附性能

利用反相悬浮分散法制备Fe3O4/壳聚糖磁性微球,并经硫脲改性(TMCS)用于吸附水溶液中Hg2+。考察了pH值、温度的影响,以及吸附动力学和吸附等温线。结果表明,TMCS为球形,粒径80μm～250μm。TMCS对Hg2+的吸附量随pH值升高而增加,但随温度升高而下降;焓变(ΔH0=-12.93kJ/mol)为负,表明吸附放热;Gibbs自由能(ΔG0=-16.41kJ/mol～-17.22kJ/mol)为负,表明吸附能自发进行。等温吸附线可用Langmuir模型拟合,最大吸附容量2.69mmol/g;吸附动力学可用拟二级模型拟合,表明化学吸附为控速步骤。吸附Hg2+后的TMCS可用0.01mol/L的EDTA脱附,脱附率达91%。     

二氧化硫脲、保险粉、亚硫酸氢钠的拔色性能

通过用二氧化硫脲、保险粉和亚硫酸氧钠、对劳瓦森染料和一系列国产染料的溶液和染色的毛皮进行拔色实验,研究了这几种材料的拔色性能。     

Electrochemical evaluation of allyl thiourea layers on copper surface

Self-assembled monolayers (SAMs) derived from adsorption of allyl thiourea onto the surface of copper in ethanol solution were evaluated in neutral aqueous sodium chloride solutions. The electrochemical behaviors and anticorrosion features of copper in the presence of allyl thiourea in neutral aqueous sodium chloride solutions were investigated by using electrochemical techniques. SAMs of allyl thiourea against copper corrosion hinder the copper oxide formation. Protective properties of allyl thiourea layers on copper surfaces depend on the applied potential, the concentration of allyl thiourea and the chloride ions in the environment. These findings should be taken into account for the use of allyl thiourea.     

湿法提金技术发展历程及应用现状

湿法提金技术由于具有工艺成熟、适应性强、相对于火法能耗低等优点,被广泛应用于黄金生产中.介绍了氰化法、硫脲法、氯化法、硫代硫酸盐法、多硫化物法及石硫合剂法等湿法提金技术的原理,分析了其优缺点,总结了湿法提金技术的发展历程及应用现状,展望了湿法提金技术的发展前景.     

含1,2,3-三唑的新型硫脲和氨基硫脲的合成

利用2-苯基-1,2,3-三唑-4-甲酰基异硫氰酸酯与2-氨基取代苯并噻唑和2-肼基取代苯并噻唑的加成反应合成了一系列二取代硫脲和氨基硫脲衍生物。研究了合成反应的条件。目标化合物经元素分析、IR和1^HNMI进行了结构确证。     

酸性硫脲法提金的研究

研究了硫脲作为主要溶金剂 ,并对各种因素进行了试验 ,选出了最佳提金方案 ,浸出率达 96.8% ,硫脲耗量只有 1 .5kg/t。     

Behavior of surface action between ethyl thiourea and chalcopyrite

1　ＩＮＴＲＯＤＵＣＴＩＯＮＩｔｉｓｗｅｌｌｋｎｏｗｎｔｈａｔｔｈｅａｄｓｏｒｐｔｉｏｎｃｈａｒａｃｔｅｒｉｓ ｔｉｃｏｆｆｌｏｔａｔｉｏｎｒｅａｇｅｎｔｏｎｍｉｎｅｒａｌｉｓａｄｅｃｉｓｉｖｅｆａｃｔｏｒｔｏｆｌｏｔａｔｉｏｎ .Ｕｓｕａｌｌｙ ,ｐｈｙｓｉｃａｌａｄｓｏｒｐｔｉｏｎｃａｕｓｅｄｂｙｖａｎｄｅｒＷａｌｌｓｆｏｒｃｅｏｒｅｌｅｃｔｒｏｓｔａｔｉｃｆｏｒｃｅｉｓｗｅａｋｗｉｔｈｎｏｏｒｌｉｔｔｌｅｓｅｌｅｃｔｉｖｉｔｙ ,ａｎｄｅｘｉｓｔｓａｍｏｎｇａｌｌｋｉｎｄｓｏｆｒｅａｇｅｎｔｓａｎ…     

通过式固相萃取-高效液相色谱法测定小麦粉及面粉处理剂中的硫脲

目的 建立通过式固相萃取柱净化,高效液相色谱法测定小麦粉及面粉处理剂(FTA)中硫脲的分析方法。方法 试样中的硫脲经乙腈-水溶液(8:2,V/V)提取,通过式固相萃取柱PRiME HLB净化,XBridge Amide色谱柱(4.6 mm×250 mm,5μm)分离,乙腈-水为流动相梯度洗脱,二极管阵列检测器(DAD)检测,外标法定量。结果 该方法在0.05～20μg/mL浓度范围线性关系良好,相关系数(R²)>0.999;检出限(LOD,S/N≥3)为0.15 mg/kg,定量限(LOQ,S/N≥10)为0.5 mg/kg;在空白小麦粉和FTA中进行3个加标水平(LOQ、2LOQ、10LOQ)的加标回收实验,方法的平均回收率在95.5%～103.7%之间,相对标准偏差(RSD)<5.7%。结论 该方法解决了酶式FTA易胶化分散效果差的问题,同时有效去除了小麦粉及FTA中的基质干扰,保护了色谱柱。该方法简单、灵敏、准确,适用于小麦粉及FTA中硫脲的准确定性、定量分析。