含碳铜钴矿石抑碳提质浮选工艺

在系统分析含碳铜钴矿石选矿工艺和技术难点的基础上,采用矿浆调整剂BK-530作碳质物的抑制剂、丁基黄药作捕收剂,对刚果(金)的KM铜钴矿石和LS铜钴矿石进行选矿试验研究,确定了抑碳铜钴浮选工艺流程,获得较好的选矿试验结果。KM铜钴矿石的闭路试验结果为铜钴混合精矿含铜22.47%、含钴2.08%,铜、钴的回收率分别为94.21%和90.52%。LS铜钴矿石的闭路试验结果为铜钴混合精矿含铜27.41%、含钴7.69%,铜、钴的回收率分别为86.33%和91.67%。

某含碳富含磁黄铁矿细粒嵌布铅锌矿石选矿工艺研究

内蒙古某含碳、富含磁黄铁矿细粒嵌布铅锌矿石,有用矿物与脉石矿物嵌布粒度细,嵌布关系复杂,含1.35%的细粒石墨碳和25%的磁黄铁矿,现场生产指标很差,试验研究表明,该矿石适合采用等可浮选流程;矿石中的石墨碳宜采用抑制的方式与铅分离,采用YT-1抑碳药剂和HX-1锌活化剂效果明显,试验室闭路试验指标高于现场生产收支平衡所需的指标,使矿山的开发盈利成为可能。

噻二唑衍生物抗氧化性及铜腐蚀抑制性的研究

在对模拟城市十五工况的台架试验各阶段的发动机润滑油采样后,用红外光谱仪分析出二巯基苯并噻二唑衍生物(DMTD-12)和二烷基二硫代磷酸锌(ZDDP)在发动机润滑油中的抑氧水平和抑碳水平,借此能找出有效降低润滑油添加剂组成中低硫(S)、低磷(P)的组分,以满足日益苛刻的环保法规要求.

难处理含碳金矿石预处理技术研究现状

难处理含碳金矿石分布广泛,通常采用常规选冶方法无法得到有效利用。分析了含碳金矿石难处理的主要原因,论述了含碳金矿石主要的预处理方法,包括浮选脱碳法、抑碳提金法、氧化焙烧法、化学氧化法等,分析了各种预处理方法的优缺点,介绍了中国含碳金矿石预处理技术工业应用现状。

广西某低硫高碳金矿选矿试验

在对广西某低硫高碳金矿石进行工艺矿物学研究的基础上,采用抑碳浮金工艺进行了选矿工艺研究。结果表明,在磨矿细度为-0.074 mm占82%的情况下,采用1粗3精1扫、中矿顺序返回流程处理该矿石,最终可获得Au品位为50.16 g/t、金回收率为80.24%的金精矿。

某复杂铜矿选矿试验研究

针对某铜矿原矿含碳较高,碳质矿物在浮选过程中极易上浮,影响最终铜产品的品位的问题,通过大量的试验研究后,在传统的浮选工艺中采用“浮选时抑碳直接选铜”工艺可得铜精矿含铜品位为19.45%,铜回收率为85.79%等较好的闭路试验指标,为该类矿石的开发利用提供借鉴。

醇燃料对汽油发动机润滑油性能影响的研究

通过对醇燃料发动机500 h程序试验,找出了发动润滑油在使用醇燃料时的氧化衰变规律和磨损规律,并初步探究了延缓其氧化衰变的方法,为醇燃料的推广提供相应的技术数据.

Influence of sodium 2,3-dihydroxypropyl dithiocarbonate on floatability of chalcopyrite and galena

Sodium 2,3-dihydroxypropyl dithiocarbonate（SGX）, which contains —OH and —CSS— in the molecule, was used to explore selective depression of galena from chalcopyrite in the flotation tests with ammonium dibutyl dithiophosphate（DDTP）, and zeta potential and adsorption measurements were performed to study the interaction between SGX and minerals. The flotation tests of single minerals show that SGX has slight activation on chalcopyrite and strong depression on galena in the whole p H range. With SGX dosage increasing, the recovery of galena decreases rapidly, while that of chalcopyrite increases slightly. At p H=6, the copper grade and recovery of concentrate are 29.52% and 82.15% respectively when mixture of two minerals is tested. Zeta potential and adsorption measurements indicate that SGX has strong adsorption on galena and slight adsorption on chalcopyrite.

Effects of sodium carbonate and calcium chloride on calcite depression in cationic flotation of pyrolusite

In the cationic flotation of pyrolusite using dodecyl ammine(DDA),the depressive effect of sodium carbonate andcalcium chloride on the calcite mineral was investigated systematically through flotation experiments,FTIR analysis,contact anglemeasurements and zeta potential tests.The microflotation experiments showed that both depressant agents decrease the flotationrecovery of calcite significantly.In addition,sodium carbonate acts as activator agent for pyrolusite,and increases its floatability.Theflotation experiments and contact angle measurements indicated that the selective depression effect of sodium carbonate on thecalcite mineral is more than that of calcium chloride.As evidenced by zeta potential and FT-IR analysis,sodium carbonate decreasesthe negative charges on the surface of calcite mineral and subsequently reduces the adsorption of DDA collector through electrostaticforces.At a pH of7.5,using2000g/t DDA and1500g/t sodium carbonate,a pyrolusite concentrate containing almost40%MnOwith71.5%recovery is achieved by carrying out the ore flotation experiments on the tabling pre-concentrate.

Biogenic isoprene emissions over China:sensitivity to the CO2 inhibition effect

Isoprene emissions emitted from vegetation are one of the most important precursors for tropospheric ozone and secondary organic aerosol formation. The authors estimate the biogenic isoprene emissions in China over 2006-2011 using a global chemical transport model （GEOS- Chem） driven by meteorological fields from the assimilated meteorological data from MERRA. The authors incorporate three different parameterizations of isoprene-CO2 interaction into the model, and perform three sensitivity simulations to investigate the effect of CO2 inhibition on isoprene emissions for the period 2006-2011 in China. The annual isoprene emissions rate across China is simulated to be 12.62 Tg C yr-1, averaged over 2006-2011, and decreases by about 2.7%-7.4% when the CO2 inhibition schemes are included. The CO2 inhibition effect might be significant in regions where the CO2 concentration and isoprene emissions are high. Estimates of isoprene emissions can differ depending on the scheme of CO2 inhibition. According to the results obtained from the sensitivity simulations, the authors find that the CO2 inhibition effect leads to 5.6% ±2.3% reductions in annual isoprene emissions over China. The authors also find that inclusion of CO2 inhibition can substantially alter the sensitivity of isoprene emissions to the changes in meteorological conditions during the study period.

Inhibitory effects of carbon dioxide insufflation on pneumoperitoneum and bowel distension after percutaneous endoscopic gastrostomy

AIM:To evaluate the inhibitory effects of carbon dioxide (CO2) insufflation on pneumoperitoneum and bowel distension after percutaneous endoscopic gastrostomy (PEG).METHODS:A total of 73 consecutive patients who were undergoing PEG were enrolled in our study.After eliminating 13 patients who fitted our exclusion criteria,60 patients were randomly assigned to either CO2 (30 patients) or air insufflation (30 patients) groups.PEG was performed by pull-through technique after threepoint fixation of the gastric wall to the abdominal wall using a gastropexy device.Arterial blood gas analysis was performed immediately before and after the procedure.Abdominal X-ray was performed at 10 min and at 24 h after PEG to assess the extent of bowel distension.Abdominal computed tomography was performed at 24 h after the procedure to detect the presence of pneumoperitoneum.The outcomes of PEG for 7 d postprocedure were also investigated.RESULTS:Among 30 patients each for the air and the CO2 groups,PEG could not be conducted in 2 patients of the CO2 group,thus they were excluded.Analyses of the remaining 58 patients showed that the patients' backgrounds were not significantly different between the two groups.The elevation values of arterial partial pressure of CO2 in the air group and the CO2 group were 2.67 mmHg and 3.32 mmHg,respectively (P = 0.408).The evaluation of bowel distension on abdominal X ray revealed a significant decrease of small bowel distension in the CO2 group compared to the air group (P < 0.001) at 10 min and 24 h after PEG,whereas there was no significant difference in large bowel distension between the two groups.Pneumoperitoneum was observed only in the air group but not in the CO2 group (P = 0.003).There were no obvious differences in the laboratory data and clinical outcomes after PEG between the two groups.CONCLUSION:There was no adverse event associated with CO2 insufflation.CO2 insufflation is considered to be safer and more comfortable for PEG patients because of the lower incidence of pneumoperitoneum and less distension of the small bowel.

Depressing behaviors and mechanism of disodium bis(carboxymethyl) trithiocarbonate on separation of chalcopyrite and molybdenite

This work focuses on the organic depressant,disodium bis(carboxymethyl)trithiocarbonate(DBT),as a selectivedepressant in copper?molybdenum sulfide flotation separation.Micro-flotation,Zeta potential,FTIR and XPS measurements werecarried out to investigate the selective depression mechanism of DBT on chalcopyrite.Zeta potential and FTIR measurementsrevealed that DBT had higher affinity for chalcopyrite than molybdenite and the XPS results of chalcopyrite before and aftertreatment with DBT further proved that DBT adsorbed on chalcopyrite surface.The investigation indicates that the mechanism ofDBT adsorbing on chalcopyrite is mainly physical adsorption.Locked circuit experiments were carried out and the results showedthat DBT could be considered as a cleaner option in commercial Cu?Mo flotation separation circuits.

ACEI attenuates the progression of CCl_4-induced rat hepatic fibrogenesis by inhibiting TGF-β1, PDGF-BB, NF-κB and MMP-2,9

AIM： Angiotensin II has pro-fibrotic function in the liver. Blockade of the renin-angiotensin-aldosterone-system （RAAS） attenuates hepatic fibrosis. The aim of the present study was to determine the mechanism of angiotensin-converting enzyme inhibitor （ACEI） on the progression of rat hepatic fibrosis. METHODS： Forty male Wistar rats were divided into three groups. Model group （Mo）： The rats were injected subcutaneously with 40% of CCl4 0.25 mL/100 g. Perindopril group （Pe）： The rats were injected subcutaneously with 40% of CCl4. Perindopril, equivalent to 2 mg/（kg·d）, was administrated. Control group （Nc）： the rats were treated with olive oil only. After 4 and 6 wk, the rats were killed. The liver sections were stained with Masson. The protein expressions of ATIR, TGF-β1 and PDGF-BB were examined by Western blot. Nuclear factor κB （NF-κB） DNA binding activity was examined by EMSA （Electrophoretic gel mobility shift assay）. Matrix metalloproteinase-2,9 （MMP-2,9） activity was assessed by zymography. Serum laminin （LN） and hyaluronic acid （HA） were measured using radioimmunoassays. RESULTS： Using Western blot, we clearly provided direct evidence for the expression of ATIR in liver. The expression was up-regulated when fibrogenesis occurred. Perindopril treatment significantly reduced mean fibrosis score, protein levels of ATIR, TGF-β1 and PDGF-BB, serum levels of HA and LN, and the activity of MMP-2,9. NF-κB DNA bindingactivity markedly increased in model group, perindopril treatment considerably reduced NF-κB DNA binding activity.CONCLUSION： Perindopril attenuates CCl4-induced hepatic fibrogenesis of rat by inhibiting TGF-β1, PDGF-BB, NF-BB and MMP-2,9.

In vitro effect of pantoprazole on lower esophageal sphincter tone in rats

AIM:To investigate the in vitro effects of pantoprazole on rat lower esophageal sphincter(LES)tone.METHODS:Rats weighing 250-300 g,provided by the Yeditepe University Experimental Research Center(Yü-DETAM),were used throughout the study.They were anesthetized before decapitation.LES tissues whose mucosal lining were removed were placed in a stan-dard 30-mL organ bath with a modif ied Krebs solution and continuously aerated with 95% oxygen-5% carbon dioxide gas mixture and kept at room temperature.The tissues were allowed to stabilize for 60 min.Sub-sequently,the contractile response to 10-6 mol/L carba-chol was obtained.Different concentrations of freshly prepared pantoprazole were added directly to the tis-sue bath to generate cumulative concentrations of 5×10-6 mol/L,5×10-5 mol/L,and 1.5×10-4 mol/L.Activi-ties were recorded on an online computer via a 4-channeltransducer data acquisition system using the software BSL PRO v 3.7,which also analyzed the data.RESULTS:Pantoprazole at 5×10-6 mol/L caused a small,but statistically insignif icant,relaxation in the car-bachol-contracted LES(2.23% vs 3.95%).The 5×10-5 mol/L concentration,however,caused a signif icant relax-ation of 10.47% compared with the control.1.5×10-4 mol/L concentration of pantoprazol caused a 19.89% relaxation in the carbachol contracted LES(P<0.001).CONCLUSION:This is the fi rst study to demonstrate that pantoprazole has a relaxing effect in isolated LESs.These results might have signif icant clinical implications for the subset of patients using proton pump inhibitors who do not receive full symptomatic alleviation from gastroesophageal reflux disease.

Capsella bursa-pastoris extract as an eco-friendly inhibitor on the corrosion of Q235 carbon steels in 1 mol·L^(-1) hydrochloric acid

The corrosion inhibition effect of Capsella bursa-pastoris extracts(CBE) for Q235 carbon steels in 1 mol·L-1hydrochloric acid solution was studied using electrochemical methods, environmental scanning electron microscopy(SEM) and Raman microscopy analysis. The polarization plots indicate that CBE serves as an effective, mixedtype inhibitor. Linear polarization resistance shows that increasing CBE concentration and temperature results in increased inhibition ef ficiency. The highest inhibition ef ficiency can reach 97% when adding 60 mg·L-1CBE,which is better than some reported plant extracts under the similar environment. The adsorption of CBE molecules is found to obey the Langmuir adsorption isotherm. Some thermodynamic and kinetic parameters for the adsorption process, such as the adsorption equilibrium constant(K), free energy of adsorption(ΔG ads), activation energy of corrosion reaction(E a) and the heat of adsorption(Q ads), are calculated and discussed. SEM and Raman microscopy analysis also demonstrate the formation of a CBE inhibition film on the metal surface.

Esophageal space-occupying lesion caused by Ascaris lumbricoides

Ascaris lumbricoides is the largest intestinal nematode parasite of man,which can lead to various complications because of its mobility.As the esophagus is not normal habitat of Ascaris,the report of esophageal ascariasis is rare.An old female presented with dysphagia after an intake of several red bean buns and haw jellies.The barium meal examination revealed a spherical defect in the lower esophagus.Esophageal bezoar or esophageal carcinoma was considered at the beginning.The patient fasted,and received fluid replacement treatment as well as some oral drugs such as proton pump inhibitor and sodium bicarbonate.Then upper gastrointestinal endoscopy was done to further confirm the diagnosis and found a live Ascaris lumbricoides in the gastric antrum and two in the duodenal bulb.The conclusive diagnosis was ascariasis.The esophageal space-occupying lesion might be the entangled worm bolus.Anthelmitnic treatment with mebendazole improved patient's clinical manifestations along with normalization of the radiological findings during a 2-wk follow-up.Authors report herein this rare case of Ascaris lumbricoides in the esophagus,emphasizing the importance of awareness of this parasitic infection as it often presents with different and unspecific symptoms.

Inhibition effect of a synthesized N,N′-bis(2-hydroxybenzaldehyde)-1,3-propandiimine on corrosion of mild steel in HCl

The corrosion inhibition of mild steel in 1 mol/L HC1 by N, N＇-bis （2-hydroxybenzaldehyde）- 1, 3-propandiimine （2-HBP） has been investigated by using potentiodynamic polarization, electrochemical impedance spectroscopy （EIS） and chronoamperometry measurements. The experimental results suggest that this compound is an excellent corrosion inhibitor for mild steel and the inhibition efficiency increases with the increase in inhibitor concentration. Polarization curves reveal that this organic compound is a mixed type inhibitor. The effect of temperature on the corrosion behavior of mild steel with the addition of the Schiff base was studied in the temperature range from 25 ℃ to 65℃. The experimentally obtained adsorption isotherms follow the Langmuir equation. Activation and thermodynamic adsorption parameters such as Ea, △H, △S,Kads and AG,ds were calculated by the corrosion currents at different temperatures and using the adsorption isotherm. The morphology of mild steel surface in the absence and presence of 2-HBP was examined by atomic force microscope （AFM） images.

Inhibiting Effect of Ciprofloxacin,Norfloxacin and Ofloxacin on Corrosion of Mild Steel in Hydrochloric Acid

The inhibiting effect of ciprofloxacin,norfloxacin and ofloxacin on the corrosion of mild steel in 1 mol·L-1 HCl and the mechanism were studied at different temperatures using mass loss measurement,electrochemical method,and X-ray photoelectron spectroscopy(XPS) .Effective inhibition was shown by mass loss,potentiodynamic polarization and impedance spectroscopy measurement.The corrosion rate of the metal in the mass loss measurement,and the corrosion reaction on cathode and anode in the electrochemical measurement were accelerated when temperature was increased.XPS results showed that the inhibitors adsorbed effectively on the metal surface.

2,3,5-Triphenyl-2H-tetrazolium Chloride and 2,4,6-Tri（2-pyridyl）-s-triazine on the Corrosion of Mild Steel in HCl

Electrochemical measurement, quantum chemical method, and scanning electron microscopy （SEM） were performed to investigate the inhibitive effect of 2,3,5-triphenyl-2H-tetrazolium chloride （TTC） and 2,4,6-tri（2-pyridyl） -s-triazine（TPT） on the corrosion of mild steel in lmol.L^-1 HCl at room temperature. Impedance spectroscopy measurement showed that the polarization resistance increased and that double layer capacitance decreased with the increase in the inhibitive concentration, and the results of potentiodynamic polarization showed that the inhibitors suppressed both cathodic and anodic processes of steel corrosion without change in the mecha-nism. Higher the orbital density distribution strength of the lowest unoccupied molecular orbital, higher is the molecule dipole, and lower energy gap between the energy of the highest occupied molecular orbital and the energy of the lowest unoccupied molecular orbital resulted in higher inhibitory efficiency. The results of SEM analysis showed that the metal-was protected from aggressive corrosion by the addition of TTC and TPT.

Corrosion inhibition and mechanism of mild steel in hydrochloric acid by ceftriaxone and amoxicillin

Corrosion inhibition of mild steel in 1 mol/L HC1 by amoxicillin and ceftriaxone in the concentration range of 1.00×10^-5-1.00×10^-2 mol/L has been studied using weight loss, electrochemical potentiodynamic polarization, electrochemical impedance spectroscopy （EIS）, scanning electron microscopy （SEM） and quantum chemistry tests at 298 K. The weight loss experiment showed that the inhibition efficiency increased with amoxicillin and ceftriaxone concentrations to attain the maximums of 80.3% and 94.1%, respectively at 1.00×10^-2 mol/L. Potentiodynamic polarization indicated that amoxicillin and ceftriaxone acted as mixed-type inhibitors but mainly inhibited cathode hydrogen evolution reaction for mild steel in 1 mol/L HC1. The electrochemical impedance spectroscopy （EIS） demonstrated the inhibitors covered the active points of metal surface to inhibit corrosion. The absorption of both inhibitors on the mild steel surface was found to follow Langmuir adsorption isothermal and dominantly involve chemical adsorption at 298 K. Scanning electron microscopy （SEM） confirmed both of the inhibitors played a significant protective effect in mild steel corrosion in 1 mol/L HC1. The relationship between the inhibition properties and molecular structure had been discussed by quantum chemistry calculation. All the experimental results concluded that both amoxicillin and ceftriaxone acted as good corrosion inhibitors and their inhibition efficiency was in the order of ceftriaxone 〉 amoxicillin.