습식 골재 생산 공정에서 모래 및 케이크 발생량 평가

정영욱,이진영,홍세선 대한자원환경지질학회 2024 자원환경지질 Vol.57 No.2

본 연구는 국내 골재 생산 과정에서 발생하는 케이크의 발생을 줄이는 방안을 찾고자 수행되었다. 8개 습식 골재 생산 업체의 케이크를 수집하여 입도를 분석하였다. A 골재 생산 현장에서 시료를 채취하고 입도 분석을 수행했다. 생산 공정을 모델링하여 모래 회수 장치 전후에서 물질 수지를 계산했다. 8개의 케이크 입도 분석 결과 하나의 시료에서 모래가 50% 포함된 사례도 있었고 나머지는 약 5~25% 포함하고 있었다. 케이크 내 다양한 모래가 포함하고 있다는 결과는 현장의 모래 회수 장치의 회수 효율이 다양함을 의미할 수 있다. A 업체 파쇄 공정에서 모래 입도는 2차 파쇄 때보다 3차 파쇄 때에 2.8배 증가했고 케이크 입자도 더 많이 발생했다. 모래 회수 공정을 모사한 결과 사이클론 및 탈수체의 분극점이 낮아질수록 모래 생산은 증가했고 케이크 발생은 적어지는 추세가 나타났다. 현장에서 케이크의 발생을 줄이기 위해서 골재생산 공정에서 특히 모래 회수 장치의 적정 운전이 필요할 것으로 판단되었다. This study was conducted to find a way to reduce the production of cakes generated in the domestic aggregate production process. Cakes from 8 wet aggregate producers were collected and particle size was analyzed. Samples were collected step by step from an aggregate producer A, particle size analysis was performed, and the material balance was calculated before and after an sand recovery unit by modeling the production process. As a result of the particle size analysis of eight cakes, one sample contained 50% sand, and the rest contained about 5% to 25% sand. The results showing that the cake contained a variety of sand in cakes may indicate that the recovery efficiency of the sand recovery units in the field varied. Sieve analysis of the samples showed that the generation of sand particles increased 2.8 times during the third crushing compared to the second crushing, and more cake particles were generated. As a result of simulating the sand recovery unit model, the lower the cut point of the cyclone and dewatering screen, the higher the sand production and the less cake production appeared. In order to reduce the production of cake in the field, it was determined that an optimal operation of the sand recovery unit was necessary in the aggregate production process.

광산배수 중화과정에서 슬러지 부피에 영향을 주는 인자 평가

정영욱,이춘오,이준학,조상현 한국자원공학회 2019 한국자원공학회지 Vol.56 No.6

일광광산 광산배수를 대상으로 중화제의 종류 및 농도, 목표 pH, 경과 시간이 슬러지 부피에 미치는 영향을평가하였다. 5, 10, 20% 액상 소석회로 pH 7까지 중화시킨 결과 고 농도 중화제 사용시 슬러지가 많이 발생했다. 20% 액상 소석회 및 NaOH로 동일 pH로 중화한 결과 소석회 사용시 슬러지 부피가 적게 발생해 중화제 종류가 슬러지 발생량에 영향을 주었다. 그러나 중화제 종류에 무관하게 슬러지 부피는 1시간 이내에 급격히 작아졌고 그 이후 서서히 감소했다. 20% 소석회로 pH 7 및 10으로 조절한 결과 높은 pH에서 슬러지 발생량이 많았다. 광산배수를 1 L 및 1 m 3 중화했을때 슬러지 부피를 비교한 결과 원수 대비 9% 및 10% 나타났다. 비이커 규모의 중화실험으로도 신뢰할 만한 슬러지 발생량을 추정할 수 있었다. In this study, the effect of neutralizer type and concentration, target pH, and elapsed time on sludge volume were evaluated using Ilkwang mine drainage. A higher neutralizer concentration produced more sludge when the pH 7 was neutralized with 5%, 10%, and 20% lime slurry. Neutralization with the same pH with 20% lime and NaOH resulted in less sludge when using lime. The type of neutralizer affected the amount of sludge produced. However, regardless of the type of neutralizer, the volume of the sludge rapidly shrank within one hour and slowly declined thereafter. The control of pH 7 and 10 with 20% lime resulted in considerable sludge at a high pH. A comparison of sludge with 1 L and 1 m 3 neutralized mine drainage showed 9% and 10% sludge volume, respectively, as compared to raw mine water. A beaker neutralization experiment was also able to estimate reliable sludge generation.

地方財政 自立性의 提高方案

鄭永旭 全北大學校 社會科學大學 1985 社會科學論叢 Vol.1 No.-

경부 림프절 절제생검술 후 상완신경총 손상으로 오진된 척수부신경 손상 1예

정영욱,허소영,이형신 대한이비인후과학회 부산,울산,경남 지부회 2019 임상이비인후과 Vol.30 No.2

Spinal accessory nerve (SAN) injury is one of the complications of neck dissection especially for posterior trian- gle lymph node biopsy and results in shoulder dysfunction and chronic pain. Variations in innervation pattern of SAN to the trapezius muscle may lead to a variable clinical presentation from patient to patient and may confuse the diagnosis. Therefore in patients with possible SAN injury, it is important to recognize the clinical symptom and determine whether the patient should have surgical treatment or conservative treatment. A 47-year old fe- male patient who underwent excisional biopsy of a lymph node located at right level V complained difficulty with right arm elevation and elbow flexion. She was initially misdiagnosed as right brachial plexus injury. Four months after initial surgery, exploration surgery was conducted. Trans-section of SAN was identified and primary nerve repair (end-to-end anastomosis) was conducted. Two months after nerve repair, shoulder pain decreased signifi- cantly and arm and shoulder movements were improved. Since injury of SAN may have similar clinical features of brachial plexus injury, clinical suspicion and surgical exploration are crucial to prevent such misdiagnosis

조성아 씨의 삶에 보내는 응원

정영욱 샘터사 2019 월간 샘터 Vol.596 No.-

SAPS조의 버섯퇴비에서 석회석 첨가가 수처리에 미치는 효과

정영욱,임길재,지상우,오참뜻,서의영,홍지혜 한국자원공학회 2020 한국자원공학회지 Vol.57 No.3

In this study, mushroom compost (MC) and mushroom compost mixed with sand-sized limestone (MCL), commonly used in successive alkalinity producing systems (SAPS), were loaded into two columns and introduced into acid mine drainage (AMD) for nine weeks to compare water quality. The mushroom compost had no neutralizing ability and, therefore, did not remove the components of Al, Fe2+, and Mn. Aluminum was continuously removed in the gravel-sized limestone layer, thereby reducing the neutralization function of limestone. The mushroom compost with sand limestone increased the pH 3.52 to 5.90 and had Al deposited in the compost layer. For nine weeks, the space of the limestone layer was maintained, pH was measured as 6.58, and alkalinity was measured as 131.09 mg/L CaCO3. Sand limestone in the mushroom compost layer thus increased pH and served as a filter for Al, thus maintaining the neutralization function of the gravel-sized limestone layer for a long time. 본 연구에서는 SAPS조에 흔히 사용하는 버섯퇴비(MC)와 모래 크기 석회석을 혼합한버섯퇴비(MCL)를 두 개의 컬럼에투입하고 9주간 광산배수를 유입시켜 수질을 비교했다. 버섯퇴비층은 중화능력이 없어서 Al, Fe2+ 및 Mn 성분을 통과시켰다. Al은자갈 석회석층에서 침전하여 석회석의 용해를 억제했다. 모래 석회석 혼합 버섯퇴비층은 pH를 5.90으로 증가시켜 Al을 버섯퇴비층에 침전시켰다. 9주 동안 자갈 석회석 층의 빈공간이 유지되었고 pH는 6.58 그리고 알칼리도는 131.09 mg/L CaCO3으로 측정되었다. 버섯퇴비층내 모래 석회석은 pH를 증가시켜서 Al을 제거해서 자갈 크기 석회석 층의 중화기능을 길게 유지하였다.

A Case of Fibrolipoma of the Nasal Septum

정영욱,김주연,김동영,권재환 대한이비인후과학회 2020 대한이비인후과학회지 두경부외과학 Vol.63 No.10

Lipoma is the most common benign neoplasm in adults. While it is commonly found in theneck, trunk, and extremities, it is extremely rare in the nasal cavity, paranasal sinus, or nasalseptum. To our knowledge, there have been only a few cases of septal lipomas reported in theEnglish literature. A 32-year-old woman visited Kosin University Hospital complaining of leftnasal congestion and throat discomfort. Upon nasal endoscopy examination and CT, we founda polypoid mass of 2.7×1.5 cm with an elongated neck occupying a region left of the nasopharyngealto the oropharyngeal cavity. The mass was completely removed via endoscopic endonasalsurgery under general anesthesia and was identified as a fibrolipoma in the histopathologicalexamination. We report a case of a successfully treated fibrolipoma originating fromthe posterior margin of the nasal septum.

지오텍스타일 튜브를 이용한 광산 슬러지의 탈수

정영욱 한국자원공학회 2017 한국자원공학회지 Vol.54 No.3

The sludge in passive treatment systems must be dewatered for final disposal because it contains a high content of water. Ton bags have been used for dewatering sludge and have a drawback to require a long time of work. This study summarizes a geotextile tube technology that overcomes a shortcoming. Geotextile tubes are being used to dewater the sludge from water treatment as well as slurry from mineral process. The larger particles flocculated by addition of polymers to sludge are left in a geotextile tube and the water is rapidly filtered. This geotextile tube technology is determined to reduce the time needed to decrease duration time of the traditional ton bag method. 자연정화 처리장에서 발생하는 슬러지는 함수율이 높아서 최종 처분을 위해서는 탈수를 해야 한다. 기존의 탈수법인 톤 백을 이용하는 방식은 탈수가 오래 걸리는 단점이 있다. 이러한 단점을 극복하는 지오텍스타일 튜브(geotextile tube) 탈수 기술을 요약하였다. 광산배수 처리 슬러지는 물론 광물처리 슬러리의 탈수를 위해서 지오텍스타일 튜브가 사용되고 있다. 폴리머를 사용해서 미세 입자를 크게 만들어 지오텍스타일 튜브내에 슬러지를 남게 하고 물은 신속히 탈수 시킨다. 본 기술이 종래 톤 백(ton bag) 방식보다 탈수 기간을 단축 하는 기술로 판단된다.

노천광산 채굴적의 수질오염방지기술 동향

정영욱,박현성 한국자원공학회 2014 한국자원공학회지 Vol.51 No.2

It is reported that pit lakes formed after the closure of open pit mines around the world can become acidic leading to contamination of the local environment. According to the literature, it is strongly recommended that countermeasures based on predictions of water quality be required for better decision before the closure of open pits. One of the useful tools for prediction of water quality before mine closure is the method which integrates several models such as hydraulic, limnological and geochemical models. It could predict changes in parameters such as stratification, alkalinity, acidity, dissolved metals in a pit lakes over time and then be used for decision making and design of pit closure plans. Attempts have been made to prevent and remediate these acidic pit lakes, using filling of waste rock and water, bacterial sulfate reduction reactions and lime dosing systems. 노천광산이 개발된 외국의 경우 폐광된 이후 채굴적이 산성호수로 변하면서 광산주변 환경을 오염시킨 사례들이 보고된다. 문헌조사에 의하면 노천광산호수로 인한 수질오염방지를 위해서 폐광 이전에 수질오염의 예측과 이를 기반으로 적절한 폐광 조치의 필요성을 강조한다. 광산호수의 수질예측 방법으로 수리-호소-지구화학 모델들을 연계하여 광산호수의 층화현상, 알칼리도, 산도 그리고 용존금속의 변화 등을 시간의 함수로 예측하며 수질오염방지 계획의 의사 결정에 활용되기도 한다. 노천채굴적 산성광산호수의 수질 오염방지를 위해서 폐석 혹은 담수 충전법, 황환원반응과 석회사용법 등이 시도되고 있다.

갑상선 수술 후 의인성 성대 마비의 위험 요인: 10년간의 단일 기관 경험

정영욱,한영석,이형신,김성원,이강대 대한이비인후과학회 2020 대한이비인후과학회지 두경부외과학 Vol.63 No.12

Background and Objectives Recurrent laryngeal nerve (RLN) palsy is a critical complicationof thyroid surgery. The aim of this study was to investigate the incidence of iatrogenic temporaryor permanent RLN palsy and to determine the surgeon’s experience factor for iatrogenicRLN palsy. Subjects and Method We retrospectively reviewed 3404 patients, who underwent thyroidectomybetween 2010 and 2019, to identify the surgeon’s experience factor for iatrogenic RLNpalsy. Information about patient demographics, surgeon factor, whether or not intraoperativeneuromonitoring (IONM) were used, and the postoperative status of RLN were collected. Theincidence of RLN injury was analyzed according to the surgeon experience, surgery for thyroidcancer, effect of IONM and the extent of surgery. Results A total of 4479 RLNs were at risk in 3094 thyroidectomies in this study. There were34 (1.10%) postoperative vocal cord palsy (VCP) cases after thyroidectomy. All patients withRLN palsy showed a unilateral type. VCP was temporary in 26 (0.84%) cases and permanentin 8 (0.26%) cases. Using the nerve at risk (NAR) method, we found that there were 34 NARpalsy out of the total (4479) NAR (0.76%), 26 NAR temporary palsy (0.58%), and 8 NAR permanentpalsy (0.18%). The mean recovery time after temporary VCP ranged between 2-180days (50.6 days in average). The incidence of permanent RLN injury was higher in surgeryconducted by less experienced surgeon (1.71% in less experienced vs. 0.05% in experiencedsurgeon, odds ratio 35.991, p<0.001). Application of IONM had no impact on incidence of iatrogenicRLN injury. Conclusion The present study demonstrated that less experienced surgeon is associated withan increased risk of iatrogenic permanent RLN palsy after thyroidectomy.