Search results for "Chloric acid"
showing 10 items of 94 documents
Simulation of a regeneration plant for spent pickling solutions via spray roasting
2015
Nowadays, pyrohydrolysis techniques are widely applied for regeneration of spent pickling liquors providing an excellent environmental and economical strategy to the problem of waste disposal/recovery, also thanks to the high acid recovery efficiencies (>99%) achieved. In fact, in these processes, iron chlorides are converted into iron oxides and hydrogen chloride at high temperature in spray roasting or fluidized bed reactors. Though the state-of-the-art technologies have been successfully applied only to large-scale plants, the development of small-scale units, able to perform a delocalized regeneration of spent solutions where these latter are actually produced, would be strongly needed …
Exploring Bioequivalence of Dexketoprofen Trometamol Drug Products with the Gastrointestinal Simulator (GIS) and Precipitation Pathways Analyses
2019
The present work aimed to explain the differences in oral performance in fasted humans who were categorized into groups based on the three different drug product formulations of dexketoprofen trometamol (DKT) salt&mdash
A joint experimental and ab initio study on the reactivity of several hydroxy selenides. Stereoselective synthesis of cis-disubstituted tetrahydrofur…
2001
Abstract The reactivity of several hydroxy selenides bearing an ethereal chain with catalytic amounts of perchloric acid in dichloromethane was investigated. Results showed that the position of the oxygen atom with respect to the seleniranium ring was crucial in order to get a good yield of the cyclized product. The factors on which yields of the 5- endo cyclization of the seleniranium ions depend were analysed by ab initio (HF/3-21G ∗ ) studies. An explanation of the different coordinating ability, towards the positively charged selenium atom, of the allylic OMe and homoallylic OH-2 groups was given.
Clarification of the oxidation state of cobalt corroles inheterogeneous and homogeneous catalytic reduction of dioxygen
2008
Co(III) corroles were investigated as efficient catalysts for the reduction of dioxygen in the presence of perchloric acid in both heterogeneous and homogeneous systems. The investigated compounds are (5,10,15-tris(pentafluorophenyl)corrole)cobalt (TPFCor)Co, (10-pentafluorophenyl-5,15-dimesitylcorrole)cobalt (F 5PhMes 2Cor)Co, and (5,10,15-trismesitylcorrole)cobalt (Mes 3Cor)Co, all of which contain bulky substituents at the three meso positions of the corrole macrocycle. Cyclic voltammetry and rotating ring-disk electrode voltammetry were used to examine the catalytic activity of the compounds when adsorbed on the surface of a graphite electrode in the presence of 1.0 M perchloric acid, a…
Lawrencium chemistry: no evidence for oxidation states lower than 3+ in aqueous solution
1988
Lawrencium (3-min 260Lr) together with other actinides, was produced in the bombardment of a 249Bk target with 18O ions. There was no sign of a reduction of Lr3+ in dilute hydrochloric acid by V2+ or Cr2+, although in the same experiments, Md3+ was reduced to Md2+ (E°=−0.2 V). The resulting limit for the reduction potential of the Lr3+/Lr1(2)+ couple is E° < −0.44 V.
Trennung von Spaltprodukten durch Extraktionschromatographie
1967
The possibilities for the separation of a complex fission product mixture by extraction chromatography have been investigated. Here the partition coefficients between three solvents and hydrochloric acid are reported for the following elements: Zn(II), Ge(IV), As(III), As(V), Se(IV), Zr(IV), Nb(V), Mo(VI), Tc(IV) Ru(III), Ru(IV), Rh(III), Ag(I), Cd(II), In(III), Sn(IV), Sb(III), Sb(V), Te(IV), I(oxidized), Cs(I), Ce(III), Tb(III), Tm(III), Ac(III), Th(IV), Pa(V), U(VI), Np(IV), Np(VI). As solvents tri-n-butylphosphate (TBP), tri-n-octylamine (TOA) and di-(2-ethylhexyl)-orthophosphoric acid (HDEHP) have been used. The partition coefficients have been measured by batch-experiments in which th…
Extraction behavior of rutherfordium into tributylphosphate from hydrochloric acid
2007
The extraction behavior of rutherfordium (Rf) into tributylphosphate (TBP) from hydrochloric acid (HCl) has been studied together with those of the lighter group-4 elements Zr and Hf. The extractability of261Rf,169Hf, and85Zr into TBP was investigated under identical conditions in 7.2–8.0 M HCl by on-line reversed-phase extraction chromatography. The percent extractions of Rf, Hf, and Zr into the TBP resin increase steeply with increasing HCl concentration, and the order of extraction is Zr > Hf ≈ Rf. By considering the order of chloride complexation among these elements, it is suggested that the stability of the TBP complex of Rf tetrachloride is lower than those of Zr and Hf.
Effect of additives on process stability of mesophilic anaerobic monodigestion of pig slaughterhouse waste
2012
The effect of two additives on anaerobic monodigestion of pig slaughterhouse waste was studied in three laboratory scale continuously stirred tank reactors (CSTRs) operated for 242-284 days at 35°C. A higher organic loading rate (OLR), namely 2.25 kg volatile solids (VS)/m(3)d with a hydraulic retention time (HRT) of 30 d was feasible with an additive containing Fe, HCl and trace elements while an OLR of 1.5 kg VS/m(3)d (HRT 30 d) led to instabilities in CSTR with an additive consisting of Fe and HCl and in CSTR without additives. Methane yields of ca. 700 dm(3) CH(4)/kg VS(fed) were obtained in all reactors under stable conditions. Both additives decreased H(2)S concentration of the biogas…
Determination of SiO 2 in lime mud by gravimetry
1999
A simple and rapid method for the determination of SiO2 in lime mud used in current sulfate pulping practice is reported. The lime mud samples are treated three times with 2.5 mL of 6 mol/L hydrochloric acid. The samples are nearly evaporated to dryness two times and the third time to complete dryness. To determine the exact SiO2 content of the residue, it is treated with an excess of concentrated hydrofluoric acid and a little hydrochloric acid, and the silica is expelled as volatile silicon tetrafluoride. The sample treatments take about 1.5 h and the heating periods take a total of about 3.5 h. The SiO2 results were evaluated by analyzing National Institute of Standards and Technology St…
High performance liquid chromatography—atomic fluorescence spectrometric determination of arsenic species in beer samples
2003
Abstract A method has been developed for the direct determination of As(III), dimethylarsinic acid (DMA), monomethylarsonic acid (MMA) and As(V) in beers by hydride generation—atomic fluorescence spectrometry after separation of arsenic species by high performance liquid chromatography. Compounds were separated by anion-exchange chromatography with isocratic elution using KH 2 PO 4 /K 2 HPO 4 as mobile phase with elution times of 1.67, 2.08, 6.52 and 10.72 min for As(III), DMA, MMA and As(V), respectively. Parameters affecting the hydride generation of all arsenic species were studied and the best conditions were established as a reaction coil of 150 cm, for a sample injected volume of 100 …