미립무연탄의 응집에 관한연구

이재장 강원대학교 자원개발연구소 1990 자원개발연구 Vol.6 No.-

Oil과 Modified Styrene을 使用한 微粒 無煙炭의 凝集

張東星,李載長 江原大學校 産業技術硏究所 1989 産業技術硏究 Vol.7 No.-

Fine anthracite is very difficult to upgrade by conventional processes such as gravity concentration or froth flotation, because large quantities of fine coals are generated at the mining and preparation stages and a significant portion of these fine coals are mixed with gangue minerals. This study, therefore, was carried out for the purpose of improving recovery of low ash clean coal, effective beneficiation of low-grade coking coal and removal of sulphur from high-sulphur coals by employing the method of selective agglomeration using oil or polystrene flocculants, for coals which are generally hydrophobic in nature will be extracted by using flocculants. Studies were performed by varying solid concentraion concetration of bridging liquid, mixing speed and mixing time, balling speed and balling time, dispersant dosage, flocculant dosage, pulp pH, and particle size. The results were : when the methods of the oil agglomeration and selective flocculation were employ(in the two process the sample was ground to the size of -74 micron), 1) ash content of the agglomerated coal was 9.85, 7.83%, 2) combustibel recovery of it was 98.5%, 93.5%, respectively. It was observed in selective flocculation that polystyrene is an effective flocculant for coal, De-entrapment of shale from the concentrate flocculated by mechanical agitation was necessary for substantional reductions in final ash content.

고기능성 미립 실리카 제조

이재장,노범식,김동수,장광택 강원대학교 부설 석재복합신소재 제품연구센터 2000 석재연 논문집 Vol.5 No.-

본 연구에서는 attrition mill을 활용하여 분쇄시 발생하는 오염물질을 방지하고 고분자 유기물질의 첨가로 평균 입도 2-3㎛의 미립 실리카 분체에 가능성을 부여하여 규석 관련 첨단산업용 고부가가치 상품을 개발하고자 하였다. 실험결과 용기 내부의 코팅재에 따른 미립화 효율은 세라믹 > 텅스텐 카바이드 > 스테인레스 > 포리우레탄 > 테프론의 순이었으며 오염방지 효과는 세라믹 > 폴리우레탄 > 텅스텐 카바이드 > 테프론 > 스테인레스의 순이었다. 고분자 유기물질의 첨가에 의해 분쇄효율이 증가하였으며, 첨가제의 일부가 표면에 코팅되어 원관의 백색도 85에서 92까지 상승되었다. 형상 조절 실험 및 백색도 향상 실험결과 첨가에에 의한 분쇄 산물은 원광보다 구형에 가까운 것을 알 수가 있었다. This study focused on manufacture of the high value-added products for a high-technology industry related to silica. The silica fines less than 3㎛ was manufactured using laboratory attrition mills with various coated liner and analysed the pollutions added from the grinding test. Ground particle's shape was investigated by adding polymer. In the grinding test, coated material of cylinder affects size reduction rate by order of ceramic, tungsten carbide, stainless steel, polyurethane, teflon. In contamination tests the coated liner affects in order of stainless steel, teflon, tungsten carbide, polyurethane, ceramic. It was found also that the result of additive test showed an instant effects of grinding and whiteness.

석회석을 이용한 vaterite 합성과 특성 연구

이재장,박종력,김호근 강원대학교 부설 석재복합신소재 제품연구센터 2003 석재연 논문집 Vol.8 No.-

국내 비금속광물 매장량의 대부분을 차지하며 강원ㆍ충청지역에 많은 매장량을 가지고 있는 석회석의 부가가치를 향상시키고자 탄산화법을 용용하여 바테라이트 결정형 침강성 탄산칼슘을 합성하고자 하였으며 현재 가행중인 석회석 광산의 시료를 사용하여 소성ㆍ수화실험 및 Ca(OH)₂-CH₃OH-H₂O-CO₂ 계에서 탄산화반응을 행하여 합성되는 바테라이트 입자의 입도 및 형상제어에 관하여 연구를 수행하였다. Ca(OH)₂-CH₃OH-H₂0-CO₂ 게의 탄산화반응에서 반응종결점은 Ca^(2+)이온의 농도가 0인 지점으로 이때의 pH는 약 9.6, 전기전도도는 100㎲/cm이었으며, H₂O-CH₃OH 비와 탄산화 반응온도, CaO 농도, 교반속도 및 CO₂가스 유량의 제어를 통하여 구형, 타원형, 판상형 및 아령형의 4가지 형상으로 바테라이트의 형상 제어가 가능하였으며 그 입도는 0.5㎛에서 5㎛의 범위 내에서의 제어가 가능하였다. In this study, we can manufacture the four types of vaterite from Ca(OH)₂ as starting material under each special carbonation reaction conditions. Vaterite formation continued until all of Ca^(2+) ions were depleted and simultaneously conductivity was 100㎲/cm. As the stirring rate goes up under the condition of lower than 1000rpm during the carbonation reaction the period of completion of reaction were getting shorter. But the period at the condition of higher than this rate wasn't changed. As the weight ratio of H₂O and CH₃OH goes up, particle size of vaterite grew up from 0.3㎛ to 0.8㎛. Yield of vaterite in above 0.45(the weight ratio of H₂O and CH₃OH) was remarkably decreased. It was found that dumbbell-like vaterite particles were formed during the carbonation reaction in methyl alcohol solution. The optimum conditions of spherical vaterite formation were H₂0-CH₃0H weight ratio of 0.26, CaO concentration of 3.0%, CO₂ gas flow rate of 500㎖/min and reaction temperature of 42℃. Ellipsoidal vaterite particles were formed under the conditions of H₂O-CH₃0H weight ratio of 0.26, CaO concentration of 3.5%, CO₂ gas flow rate of 500㎖/min and reaction temperature of 42℃. Plate-like vaterite was made also under the conditions of H₂0-CH₃0H weight ratio of 0.26, CaO concentration of 3.0%, CO₂gas flow rate of 200㎖/min and reaction temperature of 42℃. As changing the weight ratio of H₂O and CH₃OH or reaction temperature in carbonation process, particle size of vaterite could be controlled.

정선 지역 석회석의 소성특성 연구

이재장,최재석,노범식,문영배 강원대학교 산업기술연구소 2000 産業技術硏究 Vol.20 No.A

Lime is one of the world's most useful chemicals and manufactured in various types of kilns, using various fuels. Quicklimes vary in reactivity with water due to variations in the time and temperature calcining process and type of kiln used. Careful attention and control of time and temperature in the calcining process is necessary to insure a highly reactive lime. Excess time and temperature will cause the lime to be over burned. The highest reactivity of quicklime is obtained by calcination of limestone in the particle size of 0.1cm∼2cm, calcination temperature of 1000℃, calcination time 90min. It was found by the scanning electron microscopes that pores of quick lime is reducted if the soft burned quick lime is heated continually.

석회석을 이용한 바테라이트 합성에 미치는 불순물의 영향

이재장,박종력 강원대학교 부설 석재복합신소재 제품연구센터 2004 석재연 논문집 Vol.9 No.-

침강성 탄산칼슘은 고무, 페인트, 플라스틱, 제지, 잉크 등 다양한 산업분야에서 무기 충전제로 널리 이용되고 있는 주요 광물중의 하나이며 다양한 방법에 의해서 합성되고 있다. 탄산칼슘은 일반적으로 세 가지의 동질이상을 가지고 있는 것으로 알려져 있으며 이중 바테라이트는 천연적으로 산출되지 않는 것으로 여겨지고 있다. 본 연구에서는 바테라이트를 합성하기 위하여 Ca(OH)₂-CH₃OH-H₂O-CO₂계를 이용한 탄산화법을 사용하다. 이때 Ca^(2+)이온농도, pH, 전기전도도 등을 조사함으로서 바테라이트의 생성 메카니즘을 알고자 하였고, 석회석의 주요 불순물인 Fe₂O₃, Na₂O 등의 불순물이 입자 형성에 미치는 영향을 조사하였다. 연구결과 백색도가 92 이상인 바테라이트를 얻기 위해서는 Fe₂O₃ 함량이 0.03%이하이어야 하며 생성율 95%이상을 유지하기 위해서는 Na₂O의 함량이 1%이하이어야 한다는 결론을 얻을 수 있었다. Precipitated calcium carbonate is one of the most versatile mineral fillers and is consumed in an wide range of products including paper, paint, plastics, rubber, textiles, sealants, adhesives, and printing ink and can be produced by several methods. Calcium carbonate has three isomorphism; vaterite, aragonite and calcite, with numerous variations of morphology in the natural mineral or organism. Formation process of vaterite in the reaction system of Ca(OH)₂-CH₃OH-H₂O-CO₂ were investigated by measuring the electrical conductivity, Ca^(2+) ion concentration, pH in the slurries, and by means of X-ray diffraction and electron microscopic observation. It was clearly established that content of Fe₂O₃ is an important variable in whiteness and Na₂O is an important variable in vaterite's yield. We suggest that vaterite particles of whiteness over 92 are made in below 0.03% of Fe₂O₃ and yield over 50% is made in below 1% of Na₂O

석회석을 이용한 칼사이트형 탄산칼슘의 제조 및 분산특성 연구

이재장,박종력,김병곤,장광택 강원대학교 부설 석재복합신소재 제품연구센터 2002 석재연 논문집 Vol.7 No.-

석회석은 국내 비금속 광물자원의 대부분을 차지하며 강원도와 충북 등의 일부지역에 편재되어 부존하고 있다. 그러나 CaO 함량이 54% 이상인 고품위 석회석은 전체 매장량의 5% 이하로 매우 빈약한 편이다. 더욱이 대분분의 생산량이 1차 산업용으로 사용되어 부가가치가 낮은 용도로 활용되고 있다. 본 연구에서는 이러한 석회석의 부가가치를 향상시키기 위하여 칼사이트형 침강성 탄산칼슘을 탄산화법을 이용하여 합성하고자 하였으며, 합성된 탄산칼슘 분체 및 현탁액의 분산안정성에 대하여 조사하였다. 분산이 양호하고 균일한 입도의 칼사이트 분체를 얻기 위해서는 CaO 농도 3%, CO_2 가스 유입량 300㎖/min, 교반속도 1,000 rpm에서 탄산화반응시 반응온도를 10~30℃로 유지하여야 함을 알 수 있었으며, 현탁액의 분산안정제로 PMAA와 PAA를 첨가제로 사용시 pH 6, 9, 12에서 0.2 wt% 첨가할 때 우수한 분산안정성을 나타내었다. A limestone reserves in korea is comparatively enough and reserved mainly in Kangwon-do and Chungchongbuk-do. However, it is known that limestone of high grade, more than 54% CaO, is about under 5% of total reserves. Besides, most of them are used for manufacture of cement as a primary material of low value. In this study, calcite type calcium carbonate powder or slurry was synthesized by carbonation process using limestone and dispersion properties of the prepared calcium carbonate suspension was investigated. In the carbonation reaction, the temperature of lime milk must be kept 10∼30℃, CaO consentration of 3%, stirring rate of 1,000 rpm and CO_2 gas flow rate 300㎖/min to manufacture stable dispersion calcite. Also, in the result of measuring the precipitation height of calcite suspension at pH 6, 9 and 12 as a function of the PMAA and PAA content, stable dispersion properties was observed at 0.2 wt% of PMAA and PAA. This may be due to the formation of the distinct adsorption layer between calcite particles by dispersant.

銅,鉛,亞鉛鑛物의 回收에 關한 基礎的 硏究

李載長 江原大學校 産業科學硏究所 1981 産業技術硏究 Vol.1 No.-

The conclutions arrived at as a result of experimental work are as follow; 1.The use of kerosene as a collector was found essential to produce a good recovery of chalcopyrite, galena and zincblende under the condition of high pH(below 2). 2.Temperature doesn't seemingly effect the flotation of chalcopyrite, galena and zincblende. 3.The minimum concentration of kerosene as a collecter was 26mg kerosene per liter of solution.

풍촌지역 석회석을 이용한 침강성탄산칼슘의 제조

이재장,박종력 江原大學校 産業技術硏究所 2001 産業技術硏究 Vol.21 No.A

This research is focused on an improvement of additional value of high grade limestone. To obtain the basic data of precipitated calcium carbonate(PCC), studies of physical properties of limestone, calcination and hydration characteristics, the characteristics to manufacture quick lime, hydrated lime, ground calcium carbonate and precipitated calcium carbonate were performed. In the carbonation process, formation of rombohedral must be kept under 10℃ for reaction. Although the temperature of reaction of lime milk was limited under 30℃ for a colloidal PCC manufacture, over 50℃ for spindle type PCC. The recommended reaction conditions for colloidal PCC are 20℃ of reaction temperature, 4% of Ca(OH)2 concentration, 1000rpm of stirring rate and 200ml/min of CO2 gas flow rate.

폐산화은 전지로부터 수은과 은의 분리회수에 관한 연구

이재장 강원대학교 환경연구소 1996 環境硏究 Vol.13 No.-