연구발표논문초록 : 사단소소화수파법에 (死鍛燒消化水) 의한 Dolomite 로 부터 magnesium 화합물의 분리에 관한 연구

박금철 한국화학공학회 1969 `69 임시총회초록집 Vol.- No.-

철근 캐스터블 내화물의 고온특성에 관한 연구

박금철,최영섭,한문희,장영재,박근원 한국세라믹학회 1980 한국세라믹학회지 Vol.17 No.2

This study deals with the wire content, wire diameter, aspect ratio , it's arrangement of steel, wire fiber and the sorts of castable which affected the character of steel wire fiber reinformced refractory castable. Two kinds of alumina based refractory castables, one is for 1650℃ and the other is for 1800℃, and stainless steel which is SUS 304 type 0.25, 0.34 , 0.37 and 0.50m/min diameter were used respectively. Aspect ratio was adjusted to 50, 75, 100 and steel fiber content was also adjusted to 1-4wt% each. The results of the experiment were as follows : 1. At firing temperature around 1,000℃, MOR is increased with increasing wire content and aspect ratio with decreasing firing temperature, which depends on the Romualdi's Fiber Spacing Theory. But for calculation of the fiber spacing, Swamy equation is more a aplicable to the extensive fiber mixing conditions. However, the condition differs from the above at firing temperature around 1,350℃ ,because of the degradation of wire and the progress of sintering of castable. 2. Linear change is getting larger corresponding to the increase of wire content, and the spaling resistivity is increasing corresponding to the increase of wire content and to aspect ratio, and with decreasing wire diameter. 3. Firing shrinkage under load is getting greater as higher wire content, and the shrinkage of the test pieces which fiber is vertically oriented is getting greater than the test pieces which fiber is randomly oriented.

규소의 질화반응에 있어 산화마그네시움의 효과

박금철,최상원 한국세라믹학회 1983 한국세라믹학회지 Vol.20 No.4

In order to enhance the rate of th nitridation and to give the high density of reaction-bonded silicon nitride MgO powder as nitriding aid were added to silicon powders and the mixture was pressed isostatically into compacts which were nitrided in the furnace of 1, 35$0^{\circ}C$ where 95% $N_2$-5% $H_2$ gases were flowing. As the other nitriding aid $Mg(NO_3)_2 6H_2O$ was selected, A slip made of magnesium nitrate solution and fine silicon particles was spray-dried and then decomposed at 30$0^{\circ}C$. Magnesium oxide-coated silicon powders were formed into compacts prior to the nitridation on the same condition as the former. Magnesium nitrate (MgO, produced from the decomposition of magnesium nitrate) was more effective for the formation of the $\beta$-phase in the initial stage of the nitridation probably due to the easy formation of $MgO-SiO_2$-metal oxide eutectic melt. It has been confirmed that forsterite was formed as a result of the reaction between MgO and $SiO_2$ film of silicon surface. It was considered that MgO produced from magnesium nitrate may be finer more reactive and more uniformly distributed on the surface of silicon particles than original MgO. The higher the forming pressure was the more the $\beta$-phase was formed.

조립자규소 성형체의 효과적 질화가열법에 관한 연구(Densification of Silicon Nitride 3보)

박금철,최상욱 한국세라믹학회 1984 한국세라믹학회지 Vol.21 No.1

To find out the optimum heating profile for the nitridation of compacts of graded silicon grains (max 53$mu extrm{m}$) two batches with the addition of MgO and $Mg(NO_3)_3$$cdot$$6H_2O$ to silicon particles were isostatically pressed into compacts. They were nitrided under some different nitriding schedules. The properties such as bulk densitis microstructures and formed phases were measured and observed. The following results were obtained ; 1) About 10% unreacted silicon remained in specimen which was nitrided at 1, 350$^{\circ}C$ for 240hrs. 2) One of the step-heating processes 1, 150$^{\circ}C$-1, 390$^{\circ}C$ for 65hrs are then $1, 390^{\circ}C$for 50hrs was the low temperature but with that at high temperature. 3) High pressure(10.5kgf/$cm^2$) of nitrogen at 1, 390$^{\circ}C$ accelerated the $\alpha$$ ightarrow$$\beta$ transformation of silicon nitride. 4) Magnesium nitrate was superior to magnesium oxide in the role of nitriding aid and the formation of uniform microstructures.

Chamotte-점토-골석계 및 랍석 첨가계 소결체의 특성에 관한 연구

박금철,최영섭 한국세라믹학회 1977 한국세라믹학회지 Vol.14 No.4

In this study, we are observe to the sagger which is composed of cordierite-mullite system. And especialy, we investigated the characteristics of the body which composed of Chamotte-Kaolin-Plastic clay-Talc (or Clinochlore) system and Chamotte-Kaolin-Plastic clay-Agalmatolite-Talc (or Clinochlore) system. The obtained results are as follows. 1. Modulus of rupture and apparent porosity were improved by particle size of talc and clinochlore in order that -16 mesh, -6 mesh, 6-16 mesh. 2. When the body composed of talc, the modulus of rupture was increased as firing temperature was rising up but composed of clnochlore, it was reversed. 3. When added to the agalmatolite, firing shrinkage, modulus of rupture and apparent porosity were improved. 4. Mineral phases of samples fired at 125$0^{\circ}C$ above consist of cordierite, mullite and $\alpha$-cristobalite.

부소성 Ladle용 내화물에 관한 연구 -Sling mass의 특성을 중심으로-

박금철,한문희 한국세라믹학회 1978 한국세라믹학회지 Vol.15 No.4

The purpsoe of this study was to produce domestic stamping materials; sling mass which could be used as unburned refractory for iron melt'ladle. Batch compositions were based on Belgian Ladelite; mineral compositions were composed of 84 wt% of quartz and 16 wt% of clay, and particle sizes were divided into 12 wt% of 1410/297㎛, 18wt% 297/149㎛, 20wt% of 149/74㎛, 11wt% 74/44㎛ and 39wt% 44㎛ under. The effect of variable batch compositions were also investigated such as substitution of pyrophylite or industrial grade alumina for quartz and of zircon for portion of quartz and clay, increase of clay and addition on sericite. Samples were pressed at 100kg/㎠ with 7.4wt% of water or 7.4wt% of 4 wt% PVA solution. Dried and Fired properties of samples such as linear shrinkage, apparent porosity, modulus of rupture, refractoriness and corrosion resistance to blast furnace slag were investigated. The results are summarized as follows. 1. Dried samples are shrinked, but fired at 700-1400℃ expanded. Samples fired at 700-1000℃ and 1200-1400℃ tended to expand with incresing of firing temperature, but fired at 1000-1200℃ tended to shrink with increase of firing temperature. 2. Apparent porosity of samples fired at 700℃ is increased, but fired at 1200-1400℃ decreased with increasing of firing temperature. 3. Modulus of rupture of samples fired at 700℃ is decreased, but fired at above 700℃ increased with increasment of firing temperature. 4. Dried samples with 7.4 wt% of 4 wt% PVA solution better improve modulus of rupture than with 7.4 wt% of water, but the firing strength of the sampels fired at 700-1000℃ is showed reversely. 5. In quartz-clay system, mineral phases of samples fired at above 1200℃ are consisted of α-quartz, α-cristobalite and mullite. Respectively as firing temperature was rising up, intensity of α-cristobalite and mullite is in creased. 6. Quartz-Kibushi clay system, Kimcheun quartz(substitutuion of portion of industrial grade alumina for quartz) Hampyeung clay system and pyrophyllite-clay system are better in corrosion resistance to blast furnace slag than burned pyrophyllite brick. 7. 84 wt% of pyrophyllite-16wt% of clay system is superior in modulus of rupture and corrosion resistance to blast furnace slag to 84 wt% of quartz-16 wt% of clay system.

시멘트 공업과 내화물

박금철 한국시멘트협회 1982 시멘트 심포지움 Vol.10 No.-

$ZrSiO_4$ 소결체의 특성에 미치는 첨가제의 영향에 관한 연구

박금철,차명진 한국세라믹학회 1985 한국세라믹학회지 Vol.22 No.5

This study deals with sintering and corrosive behavior of sintered zircons mixed with 5wt% of clay $Cr_2O_3$ $CrO_3-MgO$ aqueous solution and $CrO_3-Mg(OH)_2$ aqueous solution. Measurements were conducted by firing specimens at 135$0^{\circ}C$ 145$0^{\circ}C$ and 155$0^{\circ}C$ 1$650^{\circ}C$ for 3hrs in oxidized and reduced atmospheric conditions. Following results were obtained. 1. Sintered zircon with 5 wt% clay showed that highest compressive strength and the lowest apparent porosity and the other showed less positive result than above specimen in order of zircon with $CrO_3-MgO$ aqueous solution $CrO_3-Mg(OH)_2$ aqueous solution and $Cr_2O_3$. 2. The more firing temperature increased the more its strength improved and porosity decreased and specimen which was fired over 155$0^{\circ}C$ and in reduced atmospheric condition showed better results. 3. Zircon with additives which was fired over 155$0^{\circ}C$ showed the evidence of thermal dissociation but it was not rebonded completely during cooling. 4. Zircon with $CrO_3-MgO$ aqueous solution and $CrO_3-Mg(OH)_2$ aqueous solutiion showed more corrosive resistance than zircon itself and zircon-clay system.

화순산 경질점토를 이용한 고온용 내화 단열벽돌의 제조에 관한 연구(I)

박금철,장영재 한국세라믹학회 1990 한국세라믹학회지 Vol.27 No.7

This study deals with the porous sintered body which is obtained by blending solid naphthalene with fine particles of Hwasun flint clay. Apparent porosity is increased, and bulk density, thermal conductivity, strength and thermal expansion are decreased according to the additiion of naphthalene. Pore shape of sintered body showed elliptical form and median size and capilary percentage are increased by adding more naphthalene.

有價證券法上(어음法 ·手票法) 어음·手票行爲의 硏究

박금철 경원전문대학 2001 論文集 Vol.23 No.-

In Modern society, we feel keenly the necessity of understanding and knowing for the bills and checks as a means of payment remittance. In this paper, we consider the comprehension(conception and kind) of bills and checks, and investigate the requisite for drawing bills and checks in the law of securities. In particular, we distinguish the formal conditions(acting signature) and essential conditions(available intention), and we apply the rules of civil law to rules for issue which has no in law securities(Law of bills and checks).