• Resources Recycling
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• v.9 no.6
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• pp.23-30
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• 2000

Since most of the waste plastics are incinerated and landfilled for the plastic treatment, the environmental friendly processes must be introduced. The plastic utilization of plastic to the blast furnace as a substitutional fuel was developed as a useful recycling method of waste plastics, and commercialized in several ironmaking company in Europe and Japan. Present study was carried out to understand the effect of plastic injection on blast furnace process continuously by using the foundry blast furnace in POSCO. The coke replacement ratio turned out to be 0.98 with the waste plastic injection up to 13.8 kg/thm of injection rate, and there were no significant effect of the kinds of injection plastics on the replacement ratio in this test operation. The permeability in the furnace became worse and the heat load in the lower part of blast furnace was increased with increasing the injection rate of waste plastics. As the rate of plastic injection were increased, the top gas utilization and shaft efficiency were also decreased from the Rist diagram analysis.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.11 no.7
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• pp.2719-2726
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• 2010

The purpose of this study was to investigate the scientific basic grounds for the assessment of health and environmental diseases resulting from air pollutants in Pohang. For this study, we investigated pollutants, weather characteristics and concentration distribution of fine particles ($PM_10$) yearly and each season, using data from Air Quality Monitoring Stations. The properties of concentration distribution and seasonal fluctuation of $PM_10$ were studied qualitatively and quantitatively using CALPUFF, air dispersion model. The average concentration of $PM_10$ for each season was spring($75.7{\mu}g/m^3$)>summer($56.8{\mu}g/m^3$)>winter($53.6{\mu}g/m^3$)>fall( $52.7{\mu}g/m^3$). In the case of spring, high concentrations appear due to the Asian dust frequently occurring. The contributions of $PM_10$ classified by the types of pollution source in Pohang were point source 62%>mobile source 33%>area source 5%. An important point is that 97% of emissions were produced from the iron manufacture in steel industry. Therefore, it is necessary to control the emission sources of pollutants and to construct an observation system at Pohang steel industrial complex from now on. It’s time to control the risk factors for health and environmental disease to protect the health of resident in Pohang and its neighboring areas.

• KDI Journal of Economic Policy
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• v.14 no.2
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• pp.3-27
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• 1992

In 1988, the government provided to the low income people 34.1% of the stocks of Pohang Iron & Steel Company through the People's Share Program of Privatization for the first time, and then in 1989 21% of the share of the Korea Electric Power Corporation were also provided to the low income classes through the same way. The purpose of the People's Share Program was known to be to support the low income classes through participating the profit of public enterprises, and also to expand the capital market through the diversification of stock holding structure. Initially, the government planned that the government share of enterprises such as the Citizens National Bank, the Korea Telecommunication Authority would be sold to the low income classes through the People's Share Program step by step. The income support policy, however, was no longer driven after 1989 when the overall stock prices started to decline. In this paper we tried to measure the effect of the privatization scheme of the public enterprises through the People's Share Program. The problems of the People's Share Program of the Pohang Iron & Steel Commpany and the Korea Electric Power Corperation were also identified. Several implications of the privatization scheme of the public enterprise through the People's Share Program by stages were found. The People's Share Program was found to be a non-stable policy measure for the income support of low income classes. The efficiency impact of the privatization through the People's Share Program was found to be non-significant.

• Proceedings of the KIEE Conference
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• 1988.11a
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• pp.56-59
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• 1988

The main purpose of Set-up control of hot strip mill plant is to obtain the most regular thickness. Then the learning or adaptive computer control in hot strip rolling mill has been developed. But it is very difficult to keep the inter-stands load distribution ratio uniform; so that the deviation of strip flatness is not avoidable. This leads to the degradation of quality of the products. In this report, an improved method base on the steepest descent method including the computation of optimum step size. This method is applied to the off-line simulation. In consequence, the better balances of inter-stands load distribution is achieved in addition to improvements of output thickness of hot strip mill in POSCO.

• Korean Journal of Metals and Materials
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• v.47 no.7
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• pp.406-415
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• 2009

A study was conducted on the effects of carbon, tungsten, and vanadium on the wear properties and surface roughness of four High Speed Steel (HSS) rolls manufactured by the centrifugal casting method. Hot-rolling simulation tests were carried out using a high-temperature wear tester capable of controlling speed, load, and temperature. HSS rolls contained a large amount (up to 25 vol.%) of carbides such as MC, $M_{2}C$, $M_{7}C_{3}$, and $M_{6}C$ carbides formed in the tempered martensite matrix. The matrix consisted mainly of lath tempered martensite when the carbon content in the matrix was small, and contained a considerable amount of plate tempered martensite when the carbon content increased. The high-temperature wear test results indicated that the wear properties and surface roughness of the rolls improved when the amount of hard MC carbides formed inside solidification cells increased. The rolls distribution was also homogeneous. The best wear properties and surface roughness were obtained from a roll where a large amount of MC carbides was homogeneously distributed in the lath tempered martensite matrix. The proper contents of carbon equivalent, tungsten equivalent, and vanadium were 2.0~2.3%, 9~10%, and 5~6%, respectively.

• 한국해양학회지
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• v.9 no.2
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• pp.59-64
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• 1974

Relative light intensity was observed with underwater illuminometer (Cs Photoelectric cell, glass window) at the mouth of Yeong-il Bay, and relative vertical clearness and extinction coefficient were calculated from the relative light intensity data. Relationship between extinction coefficient and transparency in this region is also shown.

• 제어로봇시스템학회:학술대회논문집
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• 1996.10b
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• pp.1284-1287
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• 1996

전기도금공장 ANODE 투입 및 추출 자동화 사업은 ANODE 자동투입 Robot이 개발되어 적용되기전까지는 국내에서 적용된 사례가 전혀 없었고 선진제철소에서 일부 적용된 사례가 있는 것으로만 알고 추진되었던 사업이다. 이번에 개발하여 현장에 적용한 ANODE 자동투입 robot은 가반중량이 300kg이나 되는 이동형 특수 robot으로 국산화개발품이지만 성능의 신뢰성이 입증되지 않는 상태에서 추진되었기 때문에 위험 부담성이 컸으며 완전자동화가 되기까지 많은 시행착오를 겪었다. 시행착오의 주요원인으로는 현장여건 즉 설비의 간섭, FUME에 의한 robot의 고장 또한 robot 자체의 설계 miss등 무수히 많았다. 이번 ANODE 자동투입 robot 개발 및 현장 적용으로 향후 확대 적용시 시행착오에 의한 문제점을 최소화 할수 있는 대책을 수립할수 있는 좋은 기회가 주여져 96.12.E 준공을 목표로 2차분 ANODE투입 자동화 사업이 진행중에 있으며 1차분과 시스템을 통합하여 보다 완벽한 자동화시스템을 구축할 예정이며 97년도에는 포항제철소로 확대 적용할 예정이다.

• Journal of agricultural medicine and community health
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• v.21 no.1
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• pp.61-73
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• 1996

This study conducted to determine the attitude on environment pollution by Pohang city citizens. 1,059 Pohang city citizens in the age group 20 and over were chosen and surveyed by officials's interview at Up, Myun and Dong during the period 6 September to 20 September 1995. The issue problems to be solved in Pohang city were traffic control 47.3%, environment pollution 22.7%, cultural institutions 11.6%, water service 9.9%, education system 5.1% and community security 2.1%. The 55.1% of subjects responded that responsibility for environment pollution is every citizens duty. The trash from houses were 'garbage'(48.1%), 'waste of life'(21.8%), 'reuse trash'(15.6%) and 'one use thing'(14.5%) in order. The 66.9% of subjects responded that the trash's standard envelopes can be easily tear and its texture is not good. The respondents sometimes or often had experienced foreign bodies, sediment in the water service supply. The 45.9% of the respondents use natural water as drinking water, and the water service supply(26.7%), underground water(17.0%) and buying water(9.3%) were followed. Pertaining to the air pollution(by percent) was pollution of the steel industry complex 78.0%, combustive gas 16.6% and construction dust 1.7%. The respondents at southern district complained of respiratory tract by air pollution and the respondents at northern district complained of the visual disturbance and the offensive odor(P<0.05). Water pollution problem is factory's wastewater 56.2%, home wastewater 36.4% and livestock's wastewater 5.6% in order. The respondents at southern district complained of the noise pollution by airplanes and factories at the afternoon and the respondents at northern district complained of the noise pollution by vehicles(P<0.05).

• Journal of the Korea Academia-Industrial cooperation Society
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• v.10 no.12
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• pp.3740-3747
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• 2009

To protect the citizens' health of Gyeongju and to secure basic data for the assessment of health and environmental risk, distribution characteristics of meteorological elements were investigated and numerical simulation of wind field using RAMS model was carried out. In addition, measurement and analysis of air pollutants, forecasting the behavior air pollutants using ISC-AEROMOD view, and health and environmental risk-influenced zones were defined through managing air polluting materials to prevent health damage and property damage. According to the survey results of air pollution in Gyeongju and surroundings, average annual concentration of air pollutants in Gyeongju was slightly lower than that in Pohang and Ulsan areas, but concentration of particulate matters and nitrogen dioxide at Gyeongju Station Square and Yonggang Crossing were sometimes higher than that in Pohang and Ulsan areas. Results of the modeling of moving and diffusion of air pollutants that affect citizens' health showed that parts of the 1st through 4th industrial complexes together with POSCO were included in particulate matters and sulfur dioxide influenced areas in Pohang Steel Complex area, and that Haedo-dong, Sangdae-dong, Jecheol-dong and Jangheung-dong in Pohangnam-gu represented locally worsened air quality due to a quantity of air pollutant emission from dense steel industries and large scale industrial facilities.

• Journal of the Korean Professional Engineers Association
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• v.31 no.1
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• pp.74-84
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• 1998

본 지도업체인 쌍희금속은 1988년 2월 설립, 주생산제품은 닉켈합금선으로서 1997년 12월 현재 총매출액 7.4억원(수출 0.12억 포함) 당기순이익 0.32억원으로 종업원 9명을 포함한 개인기업 형태로 특히 총매출액의 6%를 기술투자비율에 할당하고 있는 유망 중소기업이다. 기술지도와 관련한 연선의 선재(線材)는 포항제철의 $^{ø}$8mm 태선(允線)이 주종이나 특수선(特殊線)인 경우는, 국내선재의 경우 멜팅(Melting)기술이 부족하여 독일국으로부터 $^{ø}$5.5 mm의 선재를 직수입에 의존하고 있었다. 한편 세선가공의 선재는 20여개의 Dies공구 가공공정을 통한 $^{ø}$1.3 mm의 선채를 사용하여 $^{ø}$0.6 mm의 세선(細線)을 가공하고 있었다. 그러나 인발(引拔) 기술과 관련함에 특히 Dies 공구로부터 세선(細線)을 제조한 후 마무리 공정에서의 탈지문제가 정립돼있지 못하여 End User로부터 불만사례가 종종 야기 되었다 이의 원인 규명을 기술지도를 통해 조사한 결과 소성가공유(습식형)의 인식 부족이 주원인이였다. 소성가공유의 조성은 일반적으로 식물성. 광물성, 계면활성제, 극압제 등으로 구성됨에 마무리공정에서의 탈지방법은 가공유제의 기재(Base oil)에 따라 다르다 즉 기유(基油)가 광물계인 경우는 탈지제가 용제형(TCE 등)이 양호하나 식물계인 경우는 Alkali계가 양호하다. 따라서 NaOH sol'n2~3%+분산제(기포방지제)로서 음이온인 노닐페놀 0.1~0.3%의 처방을 제시하고 설비로서는 8$0^{\circ}C$로 유지되는 조제된 알칼리 Vessel과 물중탕 설비(열풍설비 포함)등을 대입하는 공정개선으로 Dies를 통과한 중간제품의 세선 $\longrightarrow$ 탈지설비 $\longrightarrow$ 80～85$^{\circ}C$로 유지되는 열처리(Aniling)공정을 대입함에 세선의 가공경화가 없었으며 아울러 수용성 가공유의 관리 한계(사내표준화)를 설정 관리 하도록 지도함으로서 지도 전에 비해 제조원가의 절하 및 생산성 향상은 물론 세선의 신규 탈지제 개발과 공정 개선을 통하여 가열공정의 부하개선 과 최종제품인 절연선의 품질향상을 가져 왔다.