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Study of Using Carbon Dioxide for Obtaining Potassium Chloride from Cement By-Pass Dust

시멘트 바이패스 더스트 내 염화칼륨 수득을 위한 이산화탄소 적용 연구

  • Kim, Kyoungseok (Eco Composite Materials Team, Energy & Environmental Division, KICET) ;
  • Chu, Yongsik (Eco Composite Materials Team, Energy & Environmental Division, KICET)
  • 김경석 (한국세라믹기술원 에너지환경소재본부 에코복합소재센터) ;
  • 추용식 (한국세라믹기술원 에너지환경소재본부 에코복합소재센터)
  • Received : 2017.09.15
  • Accepted : 2017.11.06
  • Published : 2017.12.31

Abstract

As by-pass dust (BPD) made from cement manufactured process is designated waste, it is required to bury as high cost. The main component of BPD is potassium chloride (KCl), and used for the fertilizer. For using KCl to the fertilizer, the pH value of KCl is required as neutral or weak acid. However, it is not suitable to apply BPD into the fertilizer directly without any other treatment because BPD's pH value is shown 12.0~12.5; a high base. In this study, the carbon dioxide ($CO_2$) was used for removing calcium oxide (CaO) and reducing pH value during manufacturing process of KCl. We fixed inner condition of the carbon test chamber as $25^{\circ}C$-50RH%, and retained 0~7 hours under the 20 vol% of $CO_2$ atmosphere. After experiment, we analyzed the content of CaO and pH value from each samples. The more time exposed to $CO_2$, the content of CaO and pH value are shown. Furthermore, pH value exposed in 6 hours nearly reached 7.

시멘트 제조 공정에서 발생하는 바이패스 더스트는 지정폐기물로서 고가의 처리비용이 요구되고 있다. 바이패스 더스트의 주성분은 KCl이며, KCl은 주로 비료에 사용되고 있다. 비료에 사용하기 위해서는 pH 수준이 중성 혹은 약산성 이어야 한다. 그러나 바이패스 더스트의 pH는 12.0~12.5 수준으로, 또다른 전처리 없이 비료로 사용될 수 없다. 본 연구에서는 시멘트 바이패스 더스트에서 KCl을 수득하는 과정 중, 이산화탄소를 사용하여 산화칼슘을 제거하고, 동시에 pH 변화량을 제어하고자 하였다. 탄산화시험기 내부 분위기를 $25^{\circ}C$-50RH%로 고정한 후, 이산화탄소 20 vol% 조건에서 0~7시간으로 유지하고, 각 시간별 산화칼슘 함량 및 pH 값을 분석하였다. 이산화탄소 유지시간 증가에 따라 산화칼슘 함량 및 pH 값은 감소하였으며, 6시간 경과 후 pH 값은 7에 근접하였다.

Keywords

References

  1. Schneider, M., et al., 2011 : Sustainable cement production-present and future, CCR, 41(7), pp.642-650.
  2. Md. Saiful Islam et al., 2017 : Heavy metals in the industrial sludge and their ecological risk: A case study for a developing country, JGE, 172, pp.41-49.
  3. Gineys, N., Aouad, G., and Damidot, D., 2010 : Managing trace elements in Portland cement - Part 1 : Interactions between cement paste and heavy metals added during mixing as soluble salts, CCC, 32(8), pp.563-570. https://doi.org/10.1016/j.cemconcomp.2010.06.002
  4. Gineys, N., Aouad, G., and Damidot, D., 2011 : Managing trace elements in Portland cement - Part 2 : Comparison of two methods to incorporate Zn in a cement, CCC, 33(6), pp.629-636. https://doi.org/10.1016/j.cemconcomp.2011.03.008
  5. Christof Lanzerstorfer, 2016 : Residue from the chloride bypass de-dusting of cement kilns: Reduction of the chloride content by air classification for improved utilisation, PSEP, 104, pp.444-450. https://doi.org/10.1016/j.psep.2016.06.010
  6. Taha, R. et al., 2002 : Use of Cement Bypass Dust as Filler in Asphalt Concrete Mixtures, ASCE, 14(4), pp.338-343.
  7. Ghoraba, H. Y. et al., 2004 : Reuse of Cement Kiln Bypass Dust in the Manufacture of Ordinary Portland Cement, PPTE, 43(6), pp1723-1734.
  8. Xu, F. et al., 2009 : Content of nutrient elements of plant in KCl fertilizer, SSA, 29(3), pp.822-823.
  9. Yun, Y. M., Jeong, J. H., and Chu, Y. S., 2016 : Solubility and Yield Characteristics of KCl in Cement By-Pass Dust, KIRR, 25(3), pp.43-48.
  10. Rappaport, B. D. and Axley, J. H., 1983 : Potassium Chloride for Improved Urea Fertilizer Efficiency, SSSAJ, 48(2) pp.399-401.
  11. Thomson, C. J., Marschner, H., and Romheld, V., 1993 : Effect of nitrogen fertilizer from on pH of the bulk soil and rhizosphere, and on the growth, phosphorus, and micronutrient uptake of bean, JPN, 16(3), pp.493-506. https://doi.org/10.1080/01904169309364548
  12. Yang, Y. F. et al., 2005 : Nanostructured modification of mineral particle surface in $Ca(OH)_2-H_2O-CO_2$ system, JMPT, 170(1-2), pp.58-63.
  13. Tiller, W. A., 1991 : The Science of Crystallization: Microscopic Interfacial Phenomena, pp.327-328, Cambridge University Press, England

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