Pitting Corrosion and Passive Behavior of Type AISI 304-based Borated Stainless Steels in a Boric Acid Solution

2020 ◽  
Vol 167 (10) ◽  
pp. 101506
Author(s):  
Heon-Young Ha ◽  
Sung-Dae Kim ◽  
Jae Hoon Jang ◽  
Tae-Ho Lee ◽  
Chang-Hoon Lee ◽  
...  
Author(s):  
György Pátzay ◽  
József Dobor ◽  
Emil Csonka ◽  
Gábor Lozsi ◽  
Ferenc Feil

Borate ion exchange capacity of Purolite NRW600 strong base anion resin in hydroxide form and mixed bed NRW600+NRW100 ion exchange was investigated with static experiments. Anion exchange resin was saturated with 0.1–45 g/dm3 concentration boric acid solution in a static mixer at 20, 30, 40 and 50 °C at 150 rpm for 24 hours. Remaining borate content of saturation solutions was deter-mined with ion chromatography and ICP-OES. The amount of fixed borate as borate anions increased with the saturation borate concentration as well as in case of simple anion exchange as in case of mixed bed.Column sorption-elution study was carried out by using strong base anion exchange resins (Purolite NRW600 and Amberlite IRN78). Resins in hydroxide and in chloride forms were saturated in column with 5–40 g/dm3 boric acid solution in excess. The resin was then eluted with 200 cm3 salt free water with 5 cm3/min at 25 °C and then eluted by 1 mol/dm3 sodium-sulfate solution with 5 cm3/min. The effluent was collected and analyzed for borate content by titrimetric method. In chloride form the resin adsorbed and released much less borate. Effective borate and polyborate sorption needs hydroxide ions in resin phase.


2020 ◽  
Vol 405 ◽  
pp. 193-198
Author(s):  
Daniela Marušáková ◽  
Pavel Kůs ◽  
Lorant Szatmary ◽  
Iveta Adéla Prokůpková

We tested stability of 43 selective sorbents, covering the widest range of functional groups, efficiency of sorption, method of production, and which are theoretically useful for sorption of cesium, strontium, cobalt, arsenic and actinoids. We present 3 of them: A = TiO2, B = Al2O3 and C = MxH(TiO)4(SiO4)3 . z H2O. In first testing, sorbents were exposed to the model solution of boric acid for 168 hours, in which they were mixed in a closed container with a rotator. After the exposure, sorbent solutions were filtered and analysed by spectroscopic techniques (Infrared Spectroscopy (IR), Raman Spectroscopy (RS) and newly by Scanning Electron Microscopy (SEM), combined with Energy Dispersive Spectroscopy (EDS)). Exposed spectra were compared with spectra of new, non-exposed sorbents. In second testing, sorbents were exposed to gamma radiation for 12 days with total dose 666 ± 43 kGy, produced by cobalt bomb and analysed by same techniques. The aim of our testing was to find out how sorbents behave in model boric acid solution and what effect has the gamma radiation on sorbent spectra and to analyse sorbents by SEM with EDX.


1978 ◽  
Vol 61 (3) ◽  
pp. 720-726
Author(s):  
Ram B Roy ◽  
Anthony Buccafuri

Abstract An automated fluorometric procedure is described for assaying calcium pantothenate in multivitamin preparations. Sample extracts containing calcium pantothenate are treated on-line with a slurry of magnesium trisilicate which removes any interfering riboflavin that may be present. The nitrate is resampled, mixed online with a slurry of Dowex 50W-X4 (H+) which removes any interfering β-alanine that may be present, and dialyzed. Dialysates are hydrolyzed in an alkaline medium and reacted with a mixture of o-phthalaldehyde and 2-mercaptoethanoI in boric acid solution. The fluorescence intensity due to the formation of a fluorogenic compound is measured at 455 nm after excitation at 350 nm. The procedure developed is capable of analyzing 20 samples/hr. Analytical data indicate that calcium pantothenate is assayed reliably both from real and synthetic multivitamin preparations. The mean recovery of calcium pantothenate added to sample solutions of tablet composites was 95.4%.


2014 ◽  
Vol 59 (12) ◽  
pp. 4200-4204 ◽  
Author(s):  
Maogang He ◽  
Chao Su ◽  
Xiangyang Liu ◽  
Xuetao Qi

2008 ◽  
Vol 1201 (1) ◽  
pp. 48-53 ◽  
Author(s):  
Masaaki Musashi ◽  
Takao Oi ◽  
Motoyuki Matsuo ◽  
Masao Nomura

Sign in / Sign up

Export Citation Format

Share Document