聚酰胺修饰碳糊pH电极测定高酸溶液中的氢

将石蜡、石墨粉和聚酰胺按 5∶ 1∶ 2质量比混匀 ,制成全固型聚酰胺修饰碳糊氢电极。它在 1 %～ 1 0 %KNO3 溶液中 ,对 H+ 的线性响应范围为 1 .1 0× 1 0 - 5～7.0 2 mol/L (相关系数为 0 .9993 ) ,响应时间为 3 0～ 90 s,响应斜率为 3 0 .3 m V/p H,检出限为 5 .0 1× 1 0 - 6mol/L。对常见共存离子的选择性系数为 1 0 - 5～ 1 0 - 4。电极性能稳定 ,重现性好 ,使用寿命可长达 6 0多天 ,特别适合于高酸度溶液中 H+ 的测定。

低铜高铁高酸溶液萃取性能研究

对Lix984H在高酸高铁溶液中的萃取性能进行试验研究和工业验证。结果表明,增大溶液中的铜浓度、加大铜铁比例、降低溶液的酸度、适当增大相比和控制萃取率,有助于提高萃取过程的铜铁选择性,降低试剂单耗。

从某铜冶炼厂高砷高酸硫酸铜溶液中萃取镉

研究用胺类萃取剂N235从某铜冶炼厂烟灰处理过程高砷高酸硫酸铜溶液萃取镉。结果表明,在溶液含0.2 mol/L氯离子条件下,以20%N235+5%仲辛醇+75%磺化煤油为萃取剂,4 mol/L的氨水为反萃剂,在适宜相比条件下,三级逆流萃取镉萃取率可达99.4%,七级逆流反萃镉反萃率可达96%,获得含镉为6.77 g/L的反萃液,实现镉与铜砷等元素的高效分离以及镉的富集。

亚硫酸钠脱硫废水用于高酸含砷溶液沉砷

针对金川集团股份有限公司亚硫酸钠脱硫废水处理高酸含砷溶液进行相关的研究。亚硫酸钠脱硫废水,含有约40%的硫代硫酸钠,将其作为处理高酸含砷溶液的沉砷剂,研究相关的工艺技术条件,根据试验结果确定最佳工艺条件。工程应用证明该法效果明显,成本低廉,安全可靠。

高酸复杂含锑溶液中锑的萃取回收工艺

针对酸性多金属浸出液中锑分离回收困难的问题,提出采用萃取-反萃水解法,短流程高效率地回收浸出液中的锑,得到锑水解产物。探索了有机相组成、相比O/A、萃取时间、反萃液浓度等因素对萃取及反萃过程的影响。结果表明,最佳工艺条件如下:萃取条件为有机相组成50%TBP+50%磺化煤油(体积分数)、相比O/A 1:1、操作温度25℃、萃取时间30 min、震荡频率120 Hz、单级萃取,反萃条件为稀硫酸溶液0.25 mol/L、反萃时间30 min、相比O/A 1:1。在该条件下处理后,浸出液中80.5%的锑富集于锑水解产物中。在600℃下对固体产物进行热处理,得到物相为Sb O2和Sb2O4的锑氧化物。

从低品位含铝矿石酸浸液中回收铝

从低品位含铝矿石湿法处理过程综合回收铝,实现低品位含铝矿物的资源化或高值化利用具有重要的现实意义。以硫酸浸出低品位含铝锐钛矿原矿得到的高铝铁浸出溶液为研究对象,采用硫酸铝铵结晶沉铝—树脂吸附除铁—焙烧联合工艺制备高纯Al2O3。结果表明,在铝离子初始浓度0.70 mol/L、NH 4+/Al 3+摩尔比1.2、结晶终点温度20℃条件下,以300 r/min的速度搅拌30 min,可获得晶体纯度95.31%,铝的回收率88.19%,夹杂铁的含量1.39%的NH 4 Al(SO 4)2·12H 2 O粗产品。将NH 4 Al(SO 4)2·12H 2 O粗产品通过两次重结晶和一次树脂吸附除铁,最终在1300℃条件下焙烧可得到纯度为99.99%的Al2O3。

Corrosion properties of stainless steel 316L/Ni-Cu-P coatings in warm acidic solution

In order to improve corrosion resistance of stainless steel 316L in warm acidic solution, Ni？Cu？P coatings with high copper and phosphorus contents were deposited onto stainless steel 316L substrates via electroless plating. The structure of the film and its resistance to corrosion in a warm acidic environment were investigated using scanning electron microscopy （SEM）, energy dispersive spectroscopy （EDS）, X-ray diffraction spectrometry （XRD）, polarization curves, electrochemical impedance spectroscopy （EIS）, and dipping corrosion tests, respectively. The results demonstrate that Ni？Cu？P coatings consist of two types of nodules, which are 19.98% Cu and 39.17% Cu （mass fraction） respectively. The corrosion resistance of the 316L substrate when subjected to a warm acidic solution is significantly improved by the addition of the new type of the Ni？Cu？P coating. The as-plated coatings demonstrate better corrosion resistance than annealed coatings. As-plated coatings and those annealed at 673 K are found to corrode selectively, while pitting is observed to be the main corrosion mechanism of coatings annealed at 773 and 873 K.

Effects of iron-containing phases on transformation of sulfur-bearing ions in sodium aluminate solution

Sulfides in the high-sulfur bauxite lead to serious steel equipment corrosion and alumina product degradation via theBayer process,owing to the reactions of sulfur and iron-containing phases in the sodium aluminate solution.The effects ofiron-containing phases on the transformation of sulfur-bearing ions(S2?,223S O?,23SO?and24SO?)in sodium aluminate solutionwere investigated.Fe,Fe2O3and Fe3O4barely react with23SO?and24SO?,but all of them,particularly Fe,can promote theconversion of223S O?to23SO?and S2?in sodium aluminate solution.Fe can convert to3Fe(OH)?in solution at elevatedtemperatures,and further react with S2?to form FeS2,but Fe2O3and Fe3O4have little influence on the reaction behavior of S2?insodium aluminate solution.Increasing temperature,duration,dosage of Fe,mole ratio of Na2Ok to Al2O3and caustic sodaconcentration are beneficial to the transformation of223S O?to23SO?and S2?.The results may contribute to the development oftechnologies for alleviating the equipment corrosion and reducing caustic consumption during the high-sulfur bauxite treatment bythe Bayer process.

The Quality of High Pressure-Induced and Heat-Induced Hyuganatsu Marmalade

Hyuganatsu is a typical Japanese citrus with desirous smell and edible albedo. The objectives of this study are to establish a method for softening hyuganatsu peel without heating and a process for making a high pressure-induced （HP-） marmalade and to compare with heat-induced （H-） marmalade and citrus shaddock family marmalade. Firmness of peel was （greatest to least） pressurized at 500 MPa for 30 min, soaked in citric acid solution at pH 2.7 for 24 h, and boiled for 10 min, respectively. The cell walls of flavedo and albedo did not loosen after pressurization. However, after soaking or heating, the middle lamella of albedo separated. When flavedo was soaked at pH 2.7, 9.3% of pectin was extracted. The amount of naringin was the least in hyuganatsu 〈 pummelo 〈 grapefruit）, and juice sacs 〈 flavedo 〈 segment walls 〈 albedo, respectively. Thus, marmalade was processed. Albedo, segment walls and juice sacs of hyuganatsu were homogenized with citric acid solution （pH 2.7） and mixed with sliced flavedo. Then it was soaked for 24 h at pH 2.7. Sucrose was then added （final sugar 50%）, vacuum packed, then pressurized for 30 min at 500 MPa or boiled for 10 min, respectively. There was no significant difference in sensory evaluation between HP- and H-marmalade. However, the color, transparency and total evaluation of HP-marmalade were better than H-marmalade. Consequently, total evaluation of hyuganatsu-HP-marmalade was rated highly. So, hyuganatsu was considered to be more suitable for marmalade because it was more palatable than the others.

Promotion effect of KOH on preparation of dissolved Fe(Ⅵ)

In order to improve the yield and stability of ferrate in solution, dissolved Fe(Ⅵ) prepared with NaOH and KOH respectively was compared in this study. The results showed that KOH is more suitable than NaOH for the preparation of dissolved Fe(Ⅵ) at temperature over 50 ℃. It is found that the dissolved Fe(Ⅵ) prepared with KOH increases quickly at first, and then slowly with the increasing concentrations of OH-and ClO-, while it increases rapidly at first and then decreases rapidly with the increasing dosage of Fe(NO3)3·9H2O. These results are different from that prepared with NaOH. It can be explained that solid K2FeO4 salts can be formed in KOH solution, and it will lower the Fe(Ⅵ) concentration, counteract the decomposition of Fe(Ⅵ), and improve the yield of Fe(Ⅵ). The maximum ferrate concentration is 0.163 mol/L obtained by 100 g/L Fe(NO3)3·9H2O and 6.16 mol/L KOH at 65 ℃. The stability of Fe(VI) is greatly improved due to the hypochlorite existed in the dissolved ferrate, and only 24% Fe(Ⅵ) has been decomposed after 16 d for 1 mmol/L Fe(Ⅵ) at 25 ℃.

Leaching kinetics of low-grade copper ore with high-alkality gangues in ammonia-ammonium sulphate solution

The leaching kinetics of low-grade copper ore with high-alkality gangues was studied in ammonia-ammonium sulphate solution.The main parameters,such as ammonia and ammonium sulphate concentrations,particle size,solid-to-liquid ratio and reaction temperature,were chosen in the experiments.The results show that the increase of temperature,concentrations of ammonia and ammonium sulphate is propitious to the leaching rate of copper ore.The leaching rate increases with the decrease of particle size and solid-to-liquid ratio.The leaching rate is controlled by the diffusion through the ash layer and the activation energy is determined to be 25.54 kJ/mol.A semi-empirical equation was proposed to describe the leaching kinetics.

Non-isothermal decomposition kinetics of hydrogarnet in sodium carbonate solution

Carbonation decomposition of hydrogarnet is a significant reaction of the calcification-carbonation new method for alumina production by using low-grade bauxite.In this work,non-isothermal decomposition kinetics of hydrogarnet in sodium carbonate solution was studied by high-pressure differential scanning calorimetry(HPDSC) at different heating rates of 2,5,8,10,15 and 20 K·min^(-1),respectively.The activation energy(E_α) was calculated with the help of isoconversional method(model-free),and the reaction mechanism was determined by the differential equation method.The calculated activation energy of this reaction was 115.66 kJ·mol^(-1).Furthermore,the mechanism for decomposition reaction is Avrami-Erofeev(n=1.5),and the decomposition process is diffusion-controlled.

Effects of KMnO_4 on microstructure and corrosion resistance of microarc oxidation coatings on 2024 aluminum alloy

Microarc oxidation （MAO） coatings were prepared on 2024 aluminum alloy in a Na2SiO3-KOH electrolyte with KNinO4 addition varying from 0 to 4 g/L. The microstructure and phases of the coatings were characterized by scanning electron microscopy （SEM） and X-ray diffractometry （XRD）, respectively. The corrosion resistance of MAO coatings was evaluated by electrochemical potentiodynamic polarization in 5% （mass fraction） NaCl solution. The results show that when KMnO4 is added into base electrolyte, the growth speed of oxide coatings is increased obviously. The main phase of oxide coatings is Al2O3, and the contents of MnO2 and MnEA104 phases are increased at the top of oxide coatings with increasing the concentration of KMnO4. The solute elements participate in forming the oxide coatings. When a proper concentration of KMnO4 （2.5 g/L） is added into the base solution, the micropores of the MAO coatings are small and compact, and the corrosion resistance of oxide coatings is increased largely.

亚硫酸钠脱硫废水的资源化利用研究

本文针对贵厂亚硫酸钠脱硫废水进行了资源化利用的相关研究。该厂亚硫酸钠脱硫废水，含有约40％的硫代硫酸钠，分别将其作为处理高酸硫酸铜溶液同时回收稀贵有价金属的沉淀剂和处理高酸含砷溶液的沉砷剂，研究了相关的工艺技术条件。实验结果表明：使用脱硫废水回收的铜渣含铜约60％，方便进入铜生产流程回收；三硫化二砷渣含砷高达30％左右，渣率低，便于处理。工程应用证明该法效果明显，成本低廉，安全可靠。

Comparison of dissolution profile characteristics of 11 berberine hydrochloride tablet brands in different dissolution media

Berberine hydrochloride is commonly used to treat bacterial dysentery,gastroenteritis and other diseases.Many manufacturers are available on the market today,while the production process and formulation are quite different,which may directly affect the therapeutic effect of the drug.To this end,11 different production producers of berberine hydrochloride tablets were collected according to the pharmacopeia berberine hydrochloride dissolution method(basket method).In addition the dissolution process was carried out in four elution media with different pH,and the difference was similar(f2).Factors were calculated to evaluate in vitro dissolution requirements,and in vitro dissolution of different manufacturers of berberine hydrochloride tablets was determined by high performance liquid chromatography(HPLC).The method was verified by linearity,precision,stability and robustness.Based on the f2 value,there was a significant difference in the dissolution behavior of the formulations of most berberine hydrochloride tablet brands.This research provided the basis for further in-depth research in the later period.Although the drug specifications(0.1 g)were the same,the dissolution curve was different.This phenomenon may be attributed to the fact that the excipients and crystal form of the tablets affected the release and dissolution of the tablets in vitro.

Highly dispersed Pt species anchored on W_(18)O_(49)nanowires mediate efficient and durable hydrogen evolution in acidic water

Platinum-based material is the most efficient and durable electrocatalyst for motivating the hydrogen evolution reaction(HER)in an acidic electrolyte;however,its low abundance and high cost limit its further application in proton-exchange membrane water electrolysis(PEMWE)technology.Therefore,minimizing the Pt amount while retaining high activity would be desirable.Herein,we use defect-rich W_(18)O_(49)nanowires to anchor well-dispersed,ultrafine Pt species(Pt-W_(18)O_(49))via a freeze-drying method to avoid aggregation,further mediating an efficient and durable HER in acidic water.Density functional theory analyses also demonstrate that the strong electronic interaction between the Pt species and W_(18)O_(49)support greatly improves the HER performance.With a 1/10 Pt loading amount of the commercial 20 wt%Pt/C,the Pt-W_(18)O_(49)catalyst requires the overpotentials of 116 and 743 mV to achieve high current densities of 100 and 1000 mA cm^(−2)in 0.5 mol L^(−1)H_(2)SO_(4),outperforming those of the 20 wt%Pt/C benchmark.More importantly,the Pt-W_(18)O_(49)catalyst can sustain a high-currentdensity HER at 500 mA cm^(−2)for more than 38 h without obvious degradation.This work paves a new avenue for synergistically reducing the Pt amount and retaining high activity for real-world PEMWE.

Fluorescent carbon dots derived from lactose for assaying folic acid

The fluorescent carbon dots were successfully synthesized by simply heating the mixture of lactose and Na OH solution. The as-synthesized carbon dots had been systematically characterized by fluorescence, Fourier transform infrared(FTIR), high resolution transmission electron microscopy(HR-TEM) and ^(13)C NMR. Since the fluorescence of the carbon dots was efficiently quenched by folic acid, the carbon dots were employed as selective fluorescence probes for detecting folic acid, depending on the formation of hydrogen bond among the functional group of folic acid(–OH, –COOH and –NH_2) and –OH and –COOH of the carbon dots. Moreover, the decrease of fluorescence intensity was capable of detecting folic acid in a linear range of 6×10^(-5)–8×10^(-8) mol/L with a detection limit of 1.2×10^(-9)mol/L at a signal-to-noise ratio of 3, suggesting a promising assay for folic acid. Significantly, the practicability of this fluorescence probe to assay folic acid in human urine samples was further evaluated.

0.9% saline is neither normal nor physiological

The purpose of this review is to objectively evaluate the biochemical and pathophysiological properties of 0.9% saline （henceforth： saline） and to discuss the impact of saline infusion, specifically on systemic acid-base bal- ance and renal hemodynamics. Studies have shown that electrolyte balance, including effects of saline infusion on serum electrolytes, is often poorly understood among practicing physicians and inappropriate saline prescribing can cause increased morbidity and mortality. Large-volume （〉2 L） saline infusion in healthy adults induces hyperohloremia which is associated with metabolic acidosis, hyperkalemia, and negative protein balance. Saline overload （80 ml/kg） in rodents can cause intestinal edema and contractile dysfunction associated with activation of sodium-proton exchanger （NHE） and decrease in myosin light chain phosphorylation. Saline infusion can also adversely affect renal hemody- namics. Microperfusion experiments and real-time imaging studies have demonstrated a reduction in renal perfusion and an expansion in kidney volume, compromising 02 delivery to the renal perenchyma following saline infusion. Clinically, saline infusion for patients post abdominal and cardiovascular surgery is associated with a greater number of adverse effects including more frequent blood product transfusion and bicarbonate therapy, reduced gastric blood flow, delayed recovery of gut function, impaired cardiac contractility in response to inotropes, prolonged hospital stay, and possibly increased mortality. In critically ill patients, saline infusion, compared to balanced fluid infusions, in- creases the occurrence of acute kidney injury. In summary, saline is a highly acidic fluid. With the exception of saline infusion for patients with hypochloremic metabolic alkalosis and volume depletion due to vomiting or upper gastroin- testinal suction, indiscriminate use, especially for acutely ill patients, may cause unnecessary complications and should be avoided. More education regarding saline-related effects and adequate electrolyte management is needed.