大孔强酸树脂吸附硫脲金

研究了D072大孔强酸性阳离子交换树脂从硫脲[Tu=CS(NH2)2]浸金液中吸附Au(Tu)2+的性能和机理. 结果表明，pH=2.0时，树脂对Au(Tu)2+有优良的吸附性能，金的交换容量为78.95 mg/g (Au/干树脂)，吸附的硫脲金可用乙醇-硫酸水溶液洗脱，洗脱率可达96.5%. D072树脂对Au(Tu)2+的吸附符合Langmuir吸附模型.     

离子交换树脂实验在生物分离教学中的演示应用

生物分离工程是生物技术领域中非常重要的环节。为了让学生对吸附分离操作有更深刻的理解,设计了以D072阳离子交换树脂为固相吸附剂的离子交换固定床,并以五水硫酸铜作为溶质,和阳离子交换树脂上的氢离子进行交换,带有颜色的水合铜离子被吸附在固定床上的过程明显可视。通过改变不同盐酸浓度,考察离子强度对离子交换色谱中洗脱的影响,对离子交换容量、吸附带、固定床操作和洗脱方法等理论知识点进行了明晰演示。     

应用离子交换树脂探索维生素B_1合成新方法

研究了应用D001强酸性阳离子交换树脂作为催化剂合成维生素B1的新方法。方法以硫羟硫胺为原料,双氧水氧化生成硫酸维生素B1,再经过一定量的D001强酸性阳离子交换树脂处理,经稀盐酸洗脱浓缩、结晶至成品。研究了树脂用量、树脂温度、纯化水的稀释浓度、洗脱液浓度和催化剂的重复使用性能对反应的影响。通过试验确定可以利用D001大孔型强酸性阳离子交换树脂合成维生素B1,该工艺简化了操作,改善了环境污染,更重要的是提升了产品质量和收率。     

硫脲改性D301树脂的制备及其对AuCl_4~–的吸附性能

使用硫脲对一种苯乙烯系阴离子交换树脂——D301树脂进行改性,先在D301树脂大分子链上接枝聚甲基丙烯酸缩水甘油酯(PGMA),然后通过硫脲与PGMA的环氧基的开环反应制得硫脲改性D301树脂(TD301)。对TD301进行了扫描电子显微镜、傅里叶变换红外光谱、元素分析等表征,研究了硫脲改性条件对TD301吸附性能的影响,并考察了TD301对AuCl_4~–的吸附动力学行为。结果表明,TD301适宜的硫脲改性条件为硫脲用量2 g,反应温度90℃,反应时间8 h;在环境温度25℃,氯金酸溶液pH值为2的情况下,所制得的TD301对AuCl_4~–的吸附量可以达到300.4 mg/g;此外,TD301具有优良的再生与重复使用性能。     

混合离子交换树脂除盐的性能研究

研究了强酸型离子交换树脂D072和强碱型离子交换树脂D201混合吸附杂离子的性能。D072和D201的质量比为1∶2,考察其30℃时的吸附特性,结果表明,混合树脂符合兰格缪尔吸附模型,等温吸附平衡方程为q=7.55c/(0.97+c) (R2=0.9971)。此外,考察了树脂固定床的操作性能。进料流速与初始进料浓度对树脂固定床的穿透曲线影响显著,当液相初始进料浓度为800 mg/L、进料速度为3 min/L时,穿透时间为83 min,该操作条件大幅提高了离子交换树脂的吸附效率。     

牵线搭桥

上海慧运实业有限公司可供产品(代办托运) 丙烯醇 日本产 强酸阳离子交换树脂 001×7 强酸阳离子交换树脂 734 强酸阳离子交换树脂 001(大比重) 强酸大孔阳离子交换树脂 D001 弱酸大孔阳离子交换树脂 D113 弱酸酚醛树脂 112 强碱阴离子交换树脂 201×7 强碱阴离子交换树脂 711 强碱阴离子交换树脂 714 强碱大孔阴离子交换树脂 D201 强碱大孔阴离子交换树脂 D202 强碱大孔阴离子交换树脂 D208 弱碱大孔阴离子交换树脂 D301 弱碱大孔阴离子交换树脂 D301G 弱碱大孔阴离子交换树脂 D308 弱碱大孔阴离子交换树脂 D311 弱碱大孔阴离子交换树脂 D318 各类牌号大孔吸附树脂 地址:上海武夷路697号     

树脂法净化过氧化氢溶液的安全性能研究

通过被H2O2溶液浸泡前后不同树脂的红外谱图对比,确定了具有抗氧化能力的大孔阴、阳离子交换树脂D072、D 296为净化过氧化氢用树脂。通过D 072、D 296离子交换树脂对H2O2的吸附及脱附行为,H2O2溶液与水溶液中的离子交换平衡的对比研究,从理论上找出了H2O2分解的原因是阴离子交换树脂稳定性稍差,对H2O2的吸附量较大,一旦树脂脱离H2O2溶液,H2O2的浓度骤然增高,与树脂的化学反应加剧,不良的传热条件造成热量的累积,温度迅速上升,形成快速连锁反应,使树脂中过氧化氢瞬时分解,导致树脂的活性基团甚至惰性骨架被破坏和生产过程的不安全性。H2O2一旦中断,应立即采取措施清洗树脂。     

牵线搭桥

上海慧运实业有限公司可供产品(代办托运) 丙烯醇 日本产 强酸阳离子交换树脂 001×7 强酸阳离子交换树脂 734 强酸阳离子交换树脂 001(大比重) 强酸大孔阳离子交换树脂 D001 弱酸大孔阳离子交换树脂 D113 弱酸酚醛树脂 112 强碱阴离子交换树脂 201×7 强碱阴离子交换树脂 711 强碱阴离子交换树脂 714 强碱大孔阴离子交换树脂 D201 强碱大孔阴离子交换树脂 D202 强碱大孔阴离子交换树脂 D208 弱碱大孔阴离子交换树脂 D301 弱碱大孔阴离子交换树脂 D301G 弱碱大孔阴离子交换树脂 D308 弱碱大孔阴离子交换树脂 D311 弱碱大孔阴离子交换树脂 D318 各类牌号大孔吸附树脂 地址:上海武夷路697号五溪商务中心511室     

牵线搭桥

上海慧运实业有限公司可供产品(代办托运)丙烯醇 日本产强酸阳离子交换树脂 001×7强酸阳离子交换树脂 734强酸阳离子交换树脂 001(大比重)强酸大孔阳离子交换树脂 D001弱酸大孔阳离子交换树脂 D113弱酸酚醛树脂 112强碱阴离子交换树脂 201×7强碱阴离子交换树脂 711强碱阴离子交换树脂 714强碱大孔阴离子交换树脂 D201强碱大孔阴离子交换树脂 D202强碱大孔阴离子交换树脂 D208弱碱大孔阴离子交换树脂 D301弱碱大孔阴离子交换树脂 D301G弱碱大孔阴离子交换树脂 D308弱碱大孔阴离子交换树脂 D311弱碱大孔阴离子交换树脂 D318各类牌号大孔吸附树脂地址:上海武夷路697号     

离子交换树脂提取纯化杆菌肽的工艺优化

首先比较了732、HZ016、D152、HD-2、D061、D001-CC、D296、D301等8种不同类型的离子交换树脂对发酵液中杆菌肽的吸附和解吸效果,选出适合提取纯化杆菌肽的树脂;然后以交换容量和洗脱收率为指标,对交换pH值、交换流速和洗脱条件进行优化。结果表明,大孔强酸型阳离子交换树脂D061对杆菌肽的纯化效果较好;最佳工艺条件为:交换pH值5.0~6.0,交换流速2.5BV·h~(-1),先用0.5%氨水以流速0.5BV·h~(-1)洗脱2倍树脂体积,再用3.5%氨水洗脱3倍树脂体积,在此条件下,洗脱液中杆菌肽A含量可达66.2%,杆菌肽洗脱收率可达91%以上。所得洗脱液串联凝胶型001X4阳离子交换树脂柱进行脱盐处理,再经过脱色、萃取、结晶、干燥等精制步骤可得到生物效价高于74U·mg~(-1)的医药级杆菌肽原料药。该工艺简单可行,收率稳定,纯化效率高,为工业化生产杆菌肽奠定了理论基础。     

Gold dissolution in acidic thiourea and thiocyanate solutions

Gold dissolution in acidic solutions containing thiourea (Tu) and thiocyanate was studied using linear sweep voltammetry (LSV), electrochemical impedance spectroscopy (EIS) and surface enhanced Raman spectroscopy (SERS). A synergistic response found in that mixed ligand system promoted a higher dissolution rate than either lixiviant alone. The passivation of gold occurs in a Tu only solution, but when thiocyanate is mixed with Tu, passivation is significantly alleviated. The dissolution rate of gold in the mixed lixiviant system increases with increasing Tu and thiocyanate concentration. Results from LSV and EIS indicate that gold dissolution is controlled by a combination of charge transfer and diffusion in the mixed lixiviant system. The optimum concentration for Tu and thiocyanate is about 5 mM and 0.05 M, respectively for the rate of gold dissolution. SERS results suggest a possible formation of a mixed ligand complex involving the interaction of Au(Tu)₂⁺ and SCN⁻. Further study is necessary to identify the mixed ligand complex.     

Recovery of Gold from Thiourea,Thiocyanate, or Thiosulfate Solutions by Reduction-Precipitation with a Stabilized Form of Sodium Borohydride

Abstract

Sodium borohydride can be used as an efficient agent for reducing gold and silver in acidic solutions of thiourea, thiocyanate, thiosulfate, acid chloride, and acid nitrate. The Au(I) ion is reduced to metallic gold in the form of very fine crystals, as indicated by XRD and SEM analysis. The reduction reaction is carried out at ambient temperature for a very short period of time (30 s). The reduction of Au(I) in such solutions can be performed for a wide range of gold concentrations (2 mg/L-2 g/L). Different parameters controlling the rate of the reaction and the efficiency of borohydride were studied, namely: acidity, stoichiometry, thiourea concentration, the presence of foreign ions, and temperature. Gold reduction by sodium borohydride is more favorable in the presence of Ag⁺ and/or Zn²⁺ ions, while the presence of Fe²⁺, Co²⁺, Ni²⁺, and Cu²⁺ ions decreases the efficiency of borohydride. The reduction reaction is selective for gold and silver over base metals in a solution mixture since the reaction is carried out in acidic medium. High recovery is obtained (>99%) and the product is pure. Thiourea does not undergo any degradation reaction during the course of reduction, and it can be recycled. The process appears promising for the gold industry due to its simplicity, speed, and low capital investment requirements.     

Ion Exchange Resins for Gold Cyanide Extraction Containing a Piperazine Functionality, 2. Study of the Gold Extraction Reaction

Ion exchange technology is offered as an alternative to activated carbon for gold cyanide recovery. A new type of ion‐exchange resin (PS‐PIP) incorporating a piperazine group, linked to a styrene‐divinylbenzene macroporous network, is described. The extraction of Au(CN)₂^– and other metal cyanides with the PS‐PIP resin involves three modes of metal extraction: the protonated secondary amine groups of the resin (at acidic pH conditions), the free amine groups of the resin (at neutral and basic pH values) and the small portion of the quaternary ammonium groups participate in the gold extraction mechanism. The gold cyanide extraction reaction on the polymeric piperazine was studied by a combination of metal extraction data, from batch experiments, and IR and XPS spectroscopic analysis of the metal loaded polymers. Extraction isotherms of gold cyanide show that gold binding is possible from 40–60 mg Au/g of resin in alkaline solutions, up to 150 mg Au/g of resin in acidic solutions. Efficient stripping of gold from the resin was achieved using ethanol/water solutions of sodium hydroxide, or 0.5 mol/l thiourea in sulfuric acid solutions.     

Sorption of aurocyanide and tetrachloroaurate onto resin with guanidine ligand—an XPS approach

The guanidine ligand attached to vinylbenzyl chloride matrix as well as its sorption ability to tetrachloroaurate and dicyanoaurate ions were investigated upon using X-ray photoelectron spectroscopy. The form of metallic gold, Au(0), was not observed on gold loaded resin surface when solutions of tetrachloroaurate or potassium dicyanoaurate were used. Complete elution of gold was achieved for both regeneration media: thiourea solution and mixture of sodium hydroxide and benzoate. The results demonstrate that XPS can also be a powerful technique for the analysis of the oxidation state of sorbed metal and can be a suitable method for the confirmation of functional groups incorporated in the polymer.     

Electrochemical studies on gold electrodes in acidic solutions of thiourea containing gold (I) thiourea complex ions

Electrochemical studies were made of the behaviour of gold electrodes in degassed acidic solutions containing between 0.00l to 0.03 M thiourea and between 10^–5 to 10^–3 M gold(I)thiourea. At anodic overpotentials of up to 0.3 V the dissolution of gold was rapid, and nearly reached the maximum diffusioncontrolled rate. The exchange current density was greater than 10^–6 A cm^–2, and dissolution proceeded at 100% efficiency. At higher anodic potentials, thiourea was oxidized to formamidine disulphide and other sulphur-containing compounds and the dissolution of gold became partly inhibited, while the current efficiency decreased markedly.The reduction of gold(I)thiourea was diffusion-controlled at cathodic overpotentials between –0.15 to –0.35 V, after which slight inhibition was observed. Thiourea itself did not contribute to the cathodic reaction, but formamidine disulphide could be reduced on a freshly deposited gold surface; in the absence of gold(I)thiourea in the solution, the reduction of formamidine disulphide caused rapid passivation of the gold surface. In 0.01 M thiourea and 0.1 M sulphuric or perchloric acid, the diffusion coefficient of the Au(CS(NH₂)₂) ₂ ⁺ ion was 1·1 x 10^–5 cm² s^–1 at 30°C.The standard reduction potential at 30° C of the redox couple Au(CS(NH₂)₂) ₂ ⁺ ¦Au on a fresh gold surface wasE ₀=0.352 V, but on a passivated gold surface this value increased to as much asE ₀=041V.     

球状聚乙烯醇-硫脲共混聚合物的制备及对Cu2+的吸附

以聚乙烯醇(PVA)为基体材料,用硫脲和戊二醛的交联产物与PVA共混,将共混物滴入到凝固浴中制备出球状共混树脂.对共混树脂制备过程中的PVA含量、共混配比、凝固浴浓度、Cu2+的吸附率、Cu2+的解吸等因素进行了研究.结果表明,在PVA的质量分数含量为8.0％、PVA与硫脲的质量比为5∶1、凝固浴中磷酸氢二钠和硼酸的质...     

Inhibition and polarization studies of some substituted urea compounds for corrosion of aluminium in nitric acid

Inhibition and polarization properties of urea, thiourea (TU), acetyl thiourea (AcTu), phenyl thiourea (PhTu), o-tolyl thiourea (o-tol Tu), m-tolyl thiourea (m-tol Tu), p-tolyl thiourea (p-tol Tu), 1:3-diphenyl thiourea (di-phTu), 1:3-di-o-tolyl thiourea (di-o tol Tu), 1:3-di-m-tolyl thiourea (di-m-tol Tu) and 1 : 3-di-p-tolyl thiourea (di-p-tol Tu) have been studied in relation to the corrosion of aluminium (1060) in 20% nitric acid. The polarization experiments were carried out using potentiostatic method. The inhibition efficiencies of the inhibitors were determined at 25°, 35° and 45°C and it has been observed that the percentage inhibition efficiencies of the inhibitors increase with increase in temperature. All the inhibitors except urea obey the Langmuir adsorption isotherm below the inhibitor concentration of 300 ppm, but in no case are slopes equal to unity observed. At and above the concentration of 300 ppm, the effectiveness of the compounds decreases, which is attributed to their action as cathodic depolarizers. The inhibitive performance of the compounds is discussed in the light of electronic effects in the thioureas. The potentiostatic anodic polarization curves in the presence of the inhibitors shift towards lower current density region as compared with the curve of the uninhibited solution, but there is no proper correlation between the inhibition efficiencies and the current densities required for the passivation of aluminium.     

载硫脲树脂对Pd~(2+)的吸附与脱附性能

研究了717载硫脲树脂对Pd2+的吸附热力学、动力学及脱附特性,考察了吸附时间、pH值、温度等因素对树脂吸附Pd2+的影响。结果表明:在pH=1—5时,吸附能力最好;等温吸附服从Freundlich经验式,在303—313 K条件下,Pd2+吸附量(质量比)为60—80 mg/g的吸附焓变为-29.24—-23.98 kJ/mol,自由能变为-8.00—-7.65 kJ/mol,吸附熵变为-70.10—-52.17 J/(K.mol)。吸附动力学符合Lagergren一级速率方程,303 K时吸附速率常数为0.022 min-1,颗粒内扩散是速率控制步骤之一,膜扩散也共同影响着吸附过程。303 K下树脂静态累积饱和吸附量为144.2 mg/g。用质量分数8%硫脲-1 mol/L HCl混合液可以将树脂上的Pd2+完全解吸。     

聚冠醚用于金的分离,富集与测定

报道了以新的双酚Ａ型聚冠醇为交换柱的固定相，分离，富集和测量微量金的方法。该法操作简单，结果满意。