Innovative Process of Leaching of Nickel Supported Activated Carbon in Ammonium Sulfate

2011 ◽  
Vol 201-203 ◽  
pp. 1774-1779
Author(s):  
Ze Biao Zhang ◽  
Wan Kun Wang ◽  
Jin Hui Peng

The leaching tests of nickel supported activated carbon under normal pressure in (NH4)2SO4were studied. The effects of experimental condition, such as initial concentration of (NH4)2SO4, liquid-to-solid ratio, leaching time and leaching temperature on the leaching rate of nickel, were investigated. The results show that the leaching rate of nickel is 96.12% with initial concentration of (NH4)2SO4of 7.5%, liquid-to-solid ratio of 2, leaching time of 5h and leaching temperature of 25°C. The morphology of nickel supported activated carbon before and after leaching was characterized by XRD, which proved the effective separation of nickel and activated carbon. The leaching rate of nickel was also shown better at room temperature and atmospheric pressure. Moreover, it needn’t equipments enduring high-pressure and high temperature in the leaching process, thus reducing the costs of leaching equipments greatly. This work provides a new way to the comprehensive utilization of nickel-containing activated carbon.

2013 ◽  
Vol 591 ◽  
pp. 122-125
Author(s):  
Li Jiao Yang ◽  
Si Chen ◽  
Yan Zhang ◽  
Nan Chun Chen ◽  
Jun Gao ◽  
...  

Extracting indium from water quenching slag, which contains poor indium, by two process of leaching, the effect of different oxidants and dosages on the leaching rate of indium in water quenching slag were studied. The leaching conditions: temperature 80 °C, leaching time 2 h, the liquid to solid ratio of neutral leaching 8︰1, the liquid to solid ratio of acid leaching 2︰1, initial concentration of sulfuric acid 500 g·L-1, adding different oxidants, the concentration was detected by crystal violet spectrophotometry. Test results showed that the leaching rate of indium was significantly improved by adding hydrogen peroxide and potassium permanganate. Compared with the effect of different oxidants, the effect of potassium permanganate was significantly higher than that of hydrogen peroxide on the leaching rate of indium.


Blood ◽  
2021 ◽  
Vol 138 (Supplement 1) ◽  
pp. 830-830
Author(s):  
Pierre Toulon ◽  
Mathilde Vannini ◽  
Anny Appert-Flory ◽  
Florence Fischer ◽  
Didier Jambou ◽  
...  

Abstract Background: Direct (anti-IIa and anti-Xa) oral anticoagulants (DOACs) have a significant impact on various coagulation test results. As the correct interpretation of these tests is mandatory to prevent misclassification and subsequent clinical consequences, withholding treatment could be necessary, with the associated risk of thrombosis. Aims: To evaluate the performance of the activated carbon DOAC-Remove (5-Diagnostics, Basel, Switzerland) in extracting DOACs from plasma samples and its effect on various routine and esoteric coagulation test results. Patients, Materials and Methods: Left-over plasmas from patients treated or not with DOAC obtained in the routine laboratory workload were evaluated. Briefly, 0.8 mL of plasma sample was incubated with 1 tablet of the activated carbon for 10 min at room temperature using a rotating shaker. After a 2 min-centrifugation at 2000x g and room temperature, the supernatant was pipetted before being analyzed. Tests were performed before and after such incubation. DOACs were measured using either a specific direct thrombin inhibitor or an anti-Xa assay with specific calibrations. Routine coagulation tests (PT, aPTT, and factor(F)V, FVIII:C, FIX, fibrinogen, and D-dimer) were performed, as well as thrombophilia panel [antithrombin, protein C (PC, chromogenic and clotting assays), PS (free PS antigen and clotting assays)], and lupus anticoagulant (LA) panel [silica clotting time (SCT), and dilute Russell venom clotting time (dRVVT)]. All assays were performed using reagents from Werfen (Bedford, MA, USA) on the ACL TOP 700 analyzer. As the distribution of data was not normal, test results were compared using non-parametric tests. Results: We evaluated a total of 756 plasma samples, obtained from patients treated with dabigatran (n=139, median concentration 129 ng/mL [range:18-905]), rivaroxaban (n=157, median concentration 159 ng/mL [range:19-815]), or apixaban (n=155, median concentration=154 ng/mL (range:11-510), and from 305 patients with various disease states and not on DOAC including 35 patients on coumadin and 32 patients on heparin (UFH: n=18 ; LMWH: n=14). In untreated patients, the DOAC-Remove had no significant impact on test results (n>30 for each parameter), except for D-dimer, free PS and FVIII:C. However, the mean biases, evaluated according to Bland-Altman, were below the accepted limits, and changes would not have had any clinical relevance. In the plasma from patients treated on DOAC, the DOAC-Remove eliminated all the three DOACs, with levels far below the detection limit of the techniques after a 10 min-incubation, leading to a dramatic correction of the DOAC-induced prolongations of PT and APTT, as well as of their lowering effect on FV, FVIII and FIX activities. The same applied to the DOAC-induced elevation of PC and PS anticoagulant activities (clotting assays), and antithrombin activity in the plasma from patients on rivaroxaban and apixaban. DRVVT screen/confirm ratios, which were above the normal ranges in 45% of the patients on dabigatran (n=31), and 78% of the patients on rivaroxaban (n=32), were normalized in most samples after a 10 min-incubation with the carbon and remained positive in only 10% of the patients on dabigatran and 12% of the patients on rivaroxaban. The impact of the DOACs on the SCT screen/confirm ratio was less noticeable with baseline positive test results in only one of the samples from patients on dabigatran (n=31), and in 2 patients on rivaroxaban (n=32). Treatment with the carbon leaded to a correction in the positive sample from patient on dabigatran and in one of the two positive samples from patients on rivaroxaban. Both dRVVT and SCT test results were within the normal range in the plasma from 32 patients on apixaban before and after treatment with the activated carbon. As expected, fibrinogen, PC activity evaluated using a chromogenic assay, free PS antigen concentration, VWF:RCo and VWF:Ag were not affected by any of the 3 DOACs, and test results were not significantly different before and after incubation with the activated carbon. Conclusion: The DOAC-Remove had no effect on test results obtained in the plasma from untreated patients and from patients on traditional anticoagulants. It effectively removed all 3 tested DOACs from the plasma of treated patients, allowing an accurate measurement of routine and esoteric coagulation tests in DOAC treated patients without withholding the treatment. Disclosures No relevant conflicts of interest to declare.


2015 ◽  
Vol 814 ◽  
pp. 273-277
Author(s):  
Ping Tang ◽  
Jing Liu ◽  
Min Wei Song ◽  
Hai Ping Yu ◽  
Xu Zhang

The traditional gold leaching method is cyanidation, which carries serious security and environmental problems. More and more attention is paid to the research on non-cyanide process. A high-arsenic-and-sulphur refractory gold concentrate in Sichuan was taken as the object of study. After the roasting-oxidation pretreatment of the sample, potassium ferricyanide was adopted to carry on the process experiment on gold-leaching. The leaching results as well as correlative process conditions were both investigated. The results showed that good leaching effects could be achieved by potassium ferricyanide. When the amount of potassium ferricyanide was 60g/L, the concentration of NaOH 0.2mol/L, the liquid-solid ratio 6:1 and the leaching process at room temperature lasted for 20h, the gold leaching rate reached 88.1%. If the leaching aid CaO2 is added simultaneously, it can contribute to the gold leaching. When the amount of CaO2 was 3g/L, the gold leaching rate increased to more than 94%, the amount of potassium ferricyanide decreased to 50g/L and the leaching time reduced to 14h.


2021 ◽  
Vol 9 ◽  
Author(s):  
Olívia Salomé G. P. Soares ◽  
Erika O. Jardim ◽  
Enrique V. Ramos-Fernandez ◽  
Juan J. Villora-Picó ◽  
M. Mercedes Pastor-Blas ◽  
...  

The catalytic reduction of nitrites over Pt-In catalysts supported on activated carbon has been studied in a semi-batch reactor, at room temperature and atmospheric pressure, and using hydrogen as the reducing agent. The influence of the indium content on the activity and selectivity was evaluated. Monometallic Pt catalysts are very active for nitrite reduction, but the addition of up to 1 wt% of indium significantly increases the nitrogen selectivity from 0 to 96%. The decrease in the accessible noble metal surface area reduces the amount of hydrogen available at the catalyst surface, this favoring the combination of nitrogen-containing intermediate molecules to promote the formation of N2 instead of being deeply hydrogenated into NH4+. Several activated carbon-supported Pt-In catalysts, activated under different calcination and reduction temperatures, have been also evaluated in nitrite reduction. The catalyst calcined and reduced at 400°C showed the best performance considering both the activity and the selectivity to nitrogen. This enhanced selectivity is ascribed to the formation of Pt-In alloy. The electronic properties of Pt change upon alloy formation, as it is demonstrated by XPS.


2011 ◽  
Vol 396-398 ◽  
pp. 504-507
Author(s):  
Cheng Xi

Coal vanadium ore from Hunan was pretreated by sulfuric acid for curing. Influences of curing time, curing temperature, sulphuric acid concentration and ore size fraction on vanadium leaching rate were investigated and discussed. Test results showed that: -100 mesh ore size was cured by 20% added quantity of sulphuric acid at 180°C for 24h and was leached by agitation with tap water, the liquid solid ratio of 4: 1 at room temperature for 12h, vanadium leaching rate was 74%


2018 ◽  
Vol 69 (10) ◽  
pp. 2603-2607
Author(s):  
Firas Hashim Kamar ◽  
Salman H. Abbas ◽  
Asem Hassan Mohammed ◽  
Mihaela Emanuela Craciun ◽  
Aurelia Cristina Nechifor

This work is aiming to investigate the removal Cd(II) ions from the aqueous solution using two types of biosorbent materials: peanut shells (PS) and hazelnut shells (HS). The effect of several variables on the batch bio-sorption was studied. The process was carried out at room temperature, shacking speed 200 rpm and using fixed adsorbent diameters of 0.75 mm. The highest removal efficiency of Cd(II) ions onto PS was 91.45% in the best conditions (pH=3, initial concentration of Cd(II) ions 50 mg/ L, amount adsorbent was 0.75 g, contact time was 120 min), while the highest removal efficiency when using HS was 85.62% at pH= 4, and contact time of 160 minutes using the same initial concentration of Cd(II) ions as well as the same amount of absorbent material. Isotherm was studied for bio-sorption of Cd(II) ions using these two adsorbents, and the pseudo- first and second order models were used to study bio-sorption kinetics. The results of the infrared spectroscopy (FTIR) of (PS) and (HS) samples before and after loading for Cd(II) ions showed that hydroxyl and carboxyl groups play a major role in bio-sorption of these ions.


2002 ◽  
Vol 20 (5) ◽  
pp. 495-500 ◽  
Author(s):  
Zheng-Hong Huang ◽  
Feiyu Kang ◽  
Yong-Ping Zheng ◽  
Jun-Bing Yang ◽  
Kai-Ming Liang

The adsorption characteristics of volatile organic compounds (VOCs) on viscose rayon-based activated carbon fibres (ACFs) were investigated. ACFs with specific surface areas of 640 m2/g and 1460 m2/g were used to adsorb trace volatile organic compounds in nitrogen streams at atmospheric pressure at or near room temperature (25°C and 30°C). The experimental results showed that ACFs with different surface areas exhibited different dynamic adsorption behaviours at or near room temperature.


Introduction .—In nearly all the previous determinations of the ratio of the specific heats of gases, from measurements of the pressures and temperature before and after an adiabatic expansion, large expansion chambers of fror 50 to 130 litres capacity have been used. Professor Callendar first suggests the use of smaller vessels, and in 1914, Mercer (‘Proc. Phys. Soc.,’ vol. 26 p. 155) made some measurements with several gases, but at room temperature only, using volumes of about 300 and 2000 c. c. respectively. He obtained values which indicated that small vessels could be used, and that, with proper corrections, a considerable degree of accuracy might be obtained. The one other experimenter who has used a small expansion chamber, capacity about 1 litre, is M. C. Shields (‘Phys. Rev.,’ 1917), who measured this ratio for air and for hydrogen at room temperature, about 18° C., and its value for hydroger at — 190° C. The chief advantage gained by the use of large expansion chambers is that no correction, or at the most, a very small one, has to be made for any systematic error due to the size of the containing vessels, but it is clear that, in the determinations of the ratio of the specific heats of gases at low temperatures, the use of small vessels becomes a practical necessity in order that uniform and steady temperature conditions may be obtained. Owing, however, to the presence of a systematic error depending upon the dimensions of the expansion chamber, the magnitude of which had not been definitely settled by experiment, the following work was undertaken with the object of investigating the method more fully, especially with regard to it? applicability to the determination of this ratio at low temperatures.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Jacek Malinowski ◽  
Dagmara Jacewicz ◽  
Artur Sikorski ◽  
Mariusz Urbaniak ◽  
Przemysław Rybiński ◽  
...  

AbstractThe contemporary search for new catalysts for olefin oligomerization and polymerization is based on the study of coordinating compounds and/or organometallic compounds as post-metallocene catalysts. However known catalysts are suffered by many flaws, among others unsatisfactory activity, requirement of high pressure or instability at high temperatures. In this paper, we present a new catalyst i.e. the crystalline complex compound possesing high catalytic activity in the oligomerization of olefins, such as 2-chloro-2-propen-1-ol and ethylene under very mild conditions (room temperature, 0.12 bar for ethylene oligomerization, atmospheric pressure for 2-chloro-2-propen-1-ol oligomerization). New material—Cat-CrNP ([nitrilotriacetato-1,10-phenanthroline]chromium(III) tetrahydrate) has been obtained as crystalline form of the nitrilotriacetate complex compound of chromium(III) with 1,10-phenanthroline and characterized in terms of its crystal structure by the XRD method and by multi-analytical investigations towards its physicochemical propeties The yield of catalytic oligomerization over Cat-CrNP reached to 213.92 g · mmol−1 · h−1· bar−1 and 3232 g · mmol−1 · h−1 · bar−1 for the 2-chloro-2-propen-1-ol and ethylene, respectively. Furthemore, the synthesis of Cat-CrNP is cheap, easy to perform and solvents used during preparation are environmentally friendly.


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