scholarly journals Aluminum-Free Steelmaking: Desulfurization and Nonmetallic Inclusion Evolution of Si-Killed Steel in Contact with CaO-SiO2-CaF2-MgO Slag

Processes ◽  
2021 ◽  
Vol 9 (8) ◽  
pp. 1258
Author(s):  
Stephano P. T. Piva ◽  
Petrus Christiaan Pistorius
Keyword(s):  
Partition Coefficient ◽  
Nonmetallic Inclusion ◽  
Induction Furnace ◽  
Combustion Analysis ◽  
Electrolytic Iron ◽  
Deep Desulfurization ◽  
Silicate Inclusions ◽  
Icp Ms ◽  
Significant Concentration

In some applications, deep desulfurization and deoxidation of steels without the use of aluminum are required, using Si as a deoxidant instead, with double-saturated slags in the CaO-SiO2-CaF2-MgO system. This work studied the desulfurization and nonmetallic inclusion evolution for the system using an induction furnace and compared the results with FactSage kinetic simulations. Steel samples were taken from the steel melt and analyzed with ICP-MS and combustion analysis for chemistry, and SEM/EDS for nonmetallic inclusion quantity, size, and composition. The results indicate that the steel was deeply desulfurized, with a final sulfur partition coefficient of 580; MgO was reduced from the slag, yielding dissolved [Mg] that transformed liquid Mn–silicate inclusions into forsterite and MgO. Intentional reoxidation of the melt with oxidized electrolytic iron demonstrated a significant concentration of dissolved [Mg] in the steel, by the formation of additional forsterite and MgO upon reoxidation.

scholarly journals Copper incorporation in foraminiferal calcite: results from culturing experiments

2007 ◽  
Vol 4 (4) ◽  
pp. 493-504 ◽  
Author(s):  
L. J. de Nooijer ◽  
G. J. Reichart ◽  
A. Dueñas-Bohórquez ◽  
M. Wolthers ◽  
S. R. Ernst ◽  
...  
Keyword(s):  
Partition Coefficient ◽  
Divalent Cations ◽  
Seawater Temperature ◽  
Effect Of Temperature ◽  
Benthic Species ◽  
Laboratory Conditions ◽  
Icp Ms ◽  
Seawater Salinity ◽  
Copper Incorporation ◽  
Cu Uptake

Abstract. A partition coefficient for copper (DCu) in foraminiferal calcite has been determined by culturing individuals of two benthic species under controlled laboratory conditions. The partition coefficient of a trace element (TE) is an emperically determined relation between the TE/Ca ratio in seawater and the TE/Ca ratio in foraminiferal calcite and has been established for many divalent cations. Despite its potential to act as a tracer of human-induced, heavy metal pollution, data is not yet available for copper. Since partition coefficients are usually a function of multiple factors (seawater temperature, pH, salinity, metabolic activity of the organism, etc.), we chose to analyze calcite from specimens cultured under controlled laboratory conditions. They were subjected to different concentrations of Cu2+ (0.1–20 µmol/l) and constant temperature (10 and 20°C), seawater salinity and pH. We monitored the growth of new calcite in specimens of the temperate, shallow-water foraminifer Ammonia tepida and in the tropical, symbiont-bearing Heterostegina depressa. Newly formed chambers were analyzed for Cu/Ca ratios by laser ablation-ICP-MS. The estimated partition coefficient (0.1–0.4) was constant to within experimental error over a large range of (Cu/Ca)seawater ratios and was remarkably similar for both species. Neither did the presence or absence of symbionts affect the DCu, nor did we find a significant effect of temperature or salinity on Cu-uptake.

scholarly journals Copper incorporation in foraminiferal calcite: results from culturing experiments

2007 ◽  
Vol 4 (2) ◽  
pp. 961-991 ◽  
Author(s):  
L. J. de Nooijer ◽  
G. J. Reichart ◽  
A. Dueñas-Bohórquez ◽  
M. Wolthers ◽  
S. R. Ernst ◽  
...  
Keyword(s):  
Partition Coefficient ◽  
Divalent Cations ◽  
Seawater Temperature ◽  
Effect Of Temperature ◽  
Benthic Species ◽  
Laboratory Conditions ◽  
Icp Ms ◽  
Seawater Salinity ◽  
Copper Incorporation ◽  
Cu Uptake

Abstract. A partition coefficient for copper (DCu) in foraminiferal calcite has been determined by culturing individuals of two benthic species under controlled laboratory conditions. The partition coefficient of a trace element (TE) is an emperically determined relation between the TE/Ca ratio in seawater and the TE/Ca ratio in foraminiferal calcite and has been established for many divalent cations. Despite its potential to act as a tracer of human-induced, heavy metal pollution, data is not yet available for copper. Since partition coefficients are usually a function of multiple factors (seawater temperature, pH, salinity, metabolic activity of the organism, etc.), we chose to analyze calcite from specimens cultured under controlled laboratory conditions. They were subjected to different concentrations of Cu2+ (0.1–20 µmol/l) and constant temperature (10 and 20°C), seawater salinity and pH. We monitored the growth of new calcite in specimens of the temperate, shallow-water foraminifer Ammonia tepida and in the tropical, symbiont-bearing Heterostegina depressa. Newly formed chambers were analyzed for Cu/Ca ratios by laser ablation-ICP-MS. The calculated partition coefficient (0.1–0.4) was constant to within experimetnal error over a large range of (Cu/Ca)seawater ratios and was remarkably similar for both species. Neither did the presence or absence of symbionts affect the DCu, nor did we find a significant effect of temperature or salinity on Cu-uptake.

scholarly journals Investigation into the dephosphorization of ferromanganese alloys for the production of advanced high-strength steel

2021 ◽  
Vol 121 (9) ◽  
pp. 1-9
Author(s):  
M.P. Maphutha ◽  
J.D. Steenkamp ◽  
P.C. Pistorius
Keyword(s):  
Partition Coefficient ◽  
Steel Industry ◽  
High Strength Steel ◽  
Induction Furnace ◽  
High Strength Steels ◽  
High Strength ◽  
Laboratory Scale ◽  
Motor Vehicles ◽  
Advanced High Strength Steel ◽  
Advanced High Strength Steels

Advanced high-strength steels (AHSS) are sophisticated materials being developed by the steel industry to mitigate challenges related to the performance of motor vehicles. To meet the requirements of AHSS, the ferromanganese alloys (FeMn) utilized in the production of the steel are required to contain acceptable levels of unwanted impurities, i.e. P, S, N, H, and C. The focus of the current study was to investigate dephosphorization of ferromanganese to produce a low-P alloy that could be effectively utilized in the production of AHSS. The study involved conducting laboratory-scale testwork to study the efficiency of CaO-based slag systems to dephosphorize FeMn alloys. The addition of Na2O, CaF2, and BaO to MnO-CaO-SiO2 slag was considered. The test work was carried out in a 25 kW induction furnace at temperatures of 1350°C, 1400°C, and 1450°C. The P partition coefficient (Lp) remained small at <1, which is an indication that dephosphorization had not been achieved. The baseline slag, comprising 40%CaO-40%SiO2-20%MnO, reported higher Lpvalues. Addition of Na2O and CaF2 did not show any further benefit. Substituting half of the CaO by BaO, resulted in similar Lpvalues to those of the baseline slag under conditions of 1350°C and 1450°C at 30 minutes. In summary, based on the Lpvalues obtained, the conditions investigated with the CaO-based slags appeared to have been unfavourable for dephosphorization of FeMn alloys, as most of this impurity element remained in the alloy.

Comparison of ICP-MS and direct mercury analyzer for the analysis of mercury in pharmaceuticals

Planta Medica ◽  
2015 ◽  
Vol 81 (16) ◽  
Author(s):  
Y Kho ◽  
M Kim ◽  
NY Park ◽  
H Park ◽  
JH Shin
Keyword(s):  
Direct Mercury Analyzer ◽  
Icp Ms ◽  
Mercury Analyzer

Partition Coefficient of 133Xe between Blood and Eye Tissues

1975 ◽  
Vol 14 (04) ◽  
pp. 301-309
Author(s):  
A. Marczak ◽  
A. Moszczyńska-Kowalska ◽  
H. Kowalski
Keyword(s):  
Partition Coefficient ◽  
Aqueous Humour ◽  
Vitreous Body ◽  
Flow Measurements ◽  
Solubility Coefficient ◽  
Eye Muscles ◽  
Eye Tissues ◽  
Relative Solubility ◽  
Blood Flow Measurements

SummaryThe relative solubility coefficient of 133Xe and the tissue-blood partition coefficient for the aqueous humour vitreous body, conjunctiva and external eye muscles of the rabbit were determined in vitro at 37° C and at various haematocrit values. The partition coefficient for haematocrit 40 was: for the aqueous humour 0,49 ml/ml, for the vitreous body 0,50 ml/ml, for the conjunctiva 0,81 ml/g and for the external eye muscles 0,77 ml/g. It was found that the solubility of 133Xe in rabbit erythrocytes is about 50 per cent higher than that in human red cells. The consequences of this fact for the precision of blood flow measurements by the method of tissue clearance are discussed.

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