탄소포화철의 스래그에 의한 탈황속도론

김영홍 대한금속재료학회(대한금속학회) 1980 대한금속·재료학회지 Vol.18 No.1

Slag에 의한 탄소포화철의 탈황속도 기구를 1460℃, CO gas의 환원성 분위기 하에서 조사하였다. Slag로는 SiO₂-CaO-MgO계의 slag가 사용되었으며 탈항속도는 slag의 조성, melt geometry 및 CO gas압력, Si 및 MnO의 첨가량 등을 변화시켜가며 측정하였다. 실험결과에 따르면 탈황반응의 속도는 metal 또는 slag중의 유황의 확산속도에 좌우되는 것이 아니고 metal/slag계면에서의 전기 화학적 반응속도의 지배를 받는 것으로 생각된다. 탈황반응은 세단계를 거쳐 진행된다. 즉 Fe의 Anodic reaction과 CO발생속도에 좌우되는 초기의 가장 신속한 반응단계와 CO발생속도에만 지배를 받는 중간속도의 반응단계 및 SiO₂의 환원반응에 지배를 받는 최후의 가장 완만한 단계를 거쳐 진행된다. The kinetics of desul phurization of carbon saturated iron by CaO-MgO-SiO₂ slag was studied at 1460℃ under CO gas atmosphere varying the slag composition, melt geometry, Si and MnO additions, and ambient pressure. It was shown that the desulphurization reaction is not controlled by either diffusion of sulphur in the metal or the slag but by an electrochemical reaction. Desulphurization takes place in three different reaction stages; the intial fastest stage is dependent anodic reaction of iron transfer and CO evolution, the second medium rate stage is controlled by CO evolution, and the final slowest stage controlled by silica reduction from the silicate slag.

CaO-CaF₂-Fe₂O₃계 Slag에 의한 탄소포화 용철의 동시탈인, 탈황에 관한 연구

임성규,김영홍 울산대학교 1990 연구논문집 Vol.21 No.1

실험적 규모로 CaO-CaF₂-Fe₂O₃계 Slag를 사용하여 1350℃에서 탈인 및 탈황에 대한 거동을 규명하였다. 실험조건 용선의 초기 [Si]함량, Fe₂O₃첨가량 및 염기도를 변화시켜 결정하였다. 본 실험으로 얻어진 결과는 다음과 같다. 1) 용선중 초기 [Si]함량이 적을수록 탈인 반응에는 유리하게 작용하나, 탈황반응에는 [Si]함량이 높을수록 활발히 진행되었다. 2) 적정한 동시탈인, 탈황반응을 위하여 용선의 초기 [Si]함량이 낮아야 효율적이다. 3) 용선중 [P]의 농도는 Slag Feeding말기에 최저 수준으로 떨어졌으며, 그후 복인현상이 현저히 나타났다. 한편, 탈황반응은 복황현상이 나타나지 않았다. 4) 동시 탈인, 탈황반응에 미치는 염기도의 영향은 매우 크며, 적정염기도는 3이상이었다. 이상의 실험결과는 실제 제강조업과 일치하는 것이며, Bubbling법에 의한 CaO-CaF₂-Fe₂O₃계 Slag로부터 탄소 포화용철에 대한 탈인, 탈황율은 각각 85%와 80%를 얻을 수 있었다. Laboratory-scale experiments using CaO-CaF₂-Fe₂O₃slags were carried out to clarify the behaviors of dephosphorization and desulfurization in carbon-saturated iron a 1350℃. Experimental conditions were determined by varying initial silicon content in the molten metal, amount of Fe₂O₃and basicity of slag. The results obtained in this study were as follows. 1) The beneficial effect of lower initial silicon content in liquid iron on dephosphorization was not applied to the desulfurization. 2) It was necessary to lower initial silicon content to the appropriate value for the purpose of simultaneous dephosphorization and desulfurization. 3) The phosphorous concentration fell to a minimum value soon after the end of slag feedding, and noticeable reversion of phosphorous follow thereafter. On the other hand, substantial reversion of sulfur was not observed. 4) The influence of the slag basicity on the simultaneous dephophorization and desulfurization was great, then optimum basicity was more than 3. The results of the experiment are corresponding to the steelmaking stage. It was found that high dephosphorization and desulfurization (85% and 80%) were obtained by CaO-CaF₂-Fe₂O₃slag with N₂gas bubbling condition.

사료내 불포화지방산 및 아연부족이 흰쥐의 혈청과 주요 조직내 몇가지 화학성분에 미치는 영향

金永洪 慶北大學校 1984 論文集 Vol.38 No.-

A study was conducted as a preliminary experiment for seeking out the way of prevention and treatment of porcine parakeratosis. The relationship between low fat diet, low fat-low zinc diet and porcine parakeratosis was studied by analysing the contents of free unsaturated fatty acid, total free fatty acid, phospholipid, unsaturated fatty acid in phospholipid and zinc in serum, liver, kidney, spleen and pancreas of rats fed with the diet adjusted content of unsaturated fatty acid and zinc (low fat diet and low fat-low zinc diet). Fifteen growing rats were divided into 3 groups. First group were fed low fat-low zinc diet containing 42 ppm of zinc and 3,260 ㎎/100g of unsaturated fatty acids, second group low fat diet containing 100 ppm of zinc and 3,260 ㎎/100g of unsaturated fatty acids, and third group control diet containing 100 ppm of zinc and 4,860 ㎎/l00g of unsaturated fatty acids for 100 days. The results were summarized as follows: 1) Free unsaturated fatty acid, total free fatty acid, unsaturated fatty acid in phospholipid and phospholipid concentrations of the blood serum, liver, kidney, spleen and pancreas of low fat-low zinc group were lower than those of control group. Free unsaturated fatty acid and phospholipid concentrations in blood serum (each of 5.62 ㎎/dl, 0.75 ㎎/mI) were significantly decreased as compared with those of control group (each of 6.47 ㎎/dl, 1. 15 ㎎/ml). Especially free unsaturated fatty acid, total free fatty acid and phospholipid concentrations in pancreas were significantly decreased. 2) Zinc concentrations of the blood serum, liver, kidney, spleen and pancreas of low fat-low zinc group were significantly lower than those of control and low fat groups. 3) Free unsaturated fatty acid, total free fatty acid, unsaturated fatty acid in phospholipid and phospholipid concentrations of low fat group were. lower than those of control ;group, but the free unsaturated fatty acid and phospholipid concentrations of blood serum-and pancreas were significantly decreased as compared with those of control group. 4) Zinc concentrations of low fat group were significantly higher than those of low fat-low zinc group, but there was no significant difference in low. zinc and control groups.

용융아연에 의한 철의 침식 현상에 관하여

김영홍 울산대학교 1970 연구논문집 Vol.1 No.1

극연강재(極軟鋼材)를 440∼570℃ 범위의 여러가지 온도에서 용융아연 중에 침적(浸 漬)하여 그 침식량과 반응시간 및 온도와의 관계를 실험 조사 하였다. 495℃에서 침식량은 이상적(異常的)으로 증가하고 그 반응시간에 직선적인 비례 관계를 갖는다는 점을 확인 하였다. 또한 440∼475℃온도 범위에서는 거의 변화가 없고 520℃ 이상에서는 침식된 철분이 이보다는 많으나 급격한 증가는 없었으며 이러한 침식량들은 반응시간의 제곱근에 비례하였다. δ₁과 ξ상(相) 간의 peritectic reaction은 Schramm의 상태도에서는 530℃에서 일어남에 비하여 495℃에서 일어났었다. 이러한 결과로 부터 얻을 수 있는 결론은 도금가마(Galvanizing Kettle)의 수명을 연장하기 위해서는 Kettle Wall 외측온도가 530℃가 되지 않도록 Local over-heating을 피하여야 하며 488℃를 표준으로 도금로(鍍金爐)를 설계하지 않으면 안된다는 점이다. The relation between the reaction time, temperature and the dissolved amount was experimentally investigated by dipping the extra mild steel in the molten zinc at different temperature within the range of 440-570℃. It was found that the abnormal increase of dissolved amount took place at 495 ℃, and the relation of dissolved amount with respect to reaction time was lineary proportional. In the temperature region between 440-475℃, there were only the slight. changes and above 520℃, even though the amount of dissolved iron was larger, great increase could not be found and the dissolved amounts increased in proportion to the square root of the time. The peritectic reaction between δ₁and ξ phase took place at 495℃ in comparison to 530℃ in the Schramm's phase diagram. From these results, it was concluded that in order to lengthen the life of galvanizing kettle, it must be avoided for the outside temperature of kettle wall to reach 503℃ by local over-heating and the furnace for a kettle should be designed according to the standard temperature, 488℃.

요즘세상-RFID, 소리없는 추적자

김영홍 우리신학연구소 2004 갈라진 시대의 기쁜소식 Vol.- No.639

요즘세상-경찰의 중국동포에 대한 무원칙한 DNA 체취에 분노하며

김영홍 우리신학연구소 2004 갈라진 시대의 기쁜소식 Vol.- No.643

올림픽대교 사장교 시공보고

김영홍 대한토목학회 1989 대한토목학회지 Vol.37 No.4

이개연골막염의 치료

김영홍,김기헌,김병우 대한이비인후과학회 1973 대한이비인후과학회지 두경부외과학 Vol.16 No.-

의료인의 신분보장과 의료수가 현실화 시급

김영홍 한국의학사 1985 診斷과治療 Vol.5 No.1

AC 154kV/DC 80kV 병가 철탑의 친환경 특성 평가

김영홍,Kim, Yeong-Hong 대한전기협회 2013 전기저널 Vol.- No.444