• Title/Summary/Keyword: Limestone sludge

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Clinkering of Sewage Sludge Ash as Cement Raw Material (시멘트 원료로서 하수슬러지 소각재의 클링커링 반응 특성)

  • Ahn, Ji-Whan;You, Kwang-Suk;Cheon, Sung-Min;Han, Ki-Suk;Kim, Hwan
    • Journal of the Korean Ceramic Society
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    • v.41 no.4
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    • pp.323-327
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    • 2004
  • This study has been carried out to use the municipal solid waste sewage sludge ash generated at sewage disposal field as the raw materials of Ordinary Portland Cement (OPC). Limestone, shale, converter slag, and fly ash were used as the main raw materials. After the raw materials were mixed, these were fired at 1,300, 1,350, 1,400, 1,450, and 1,500$^{\circ}C$ for 1 h and cooled rapidly in air. The properties of clinker synthesized were examined with XRD, SEM, and burnability index by polysius method.

Determining Heavy Metal (loid) Stabilization Materials and Optimum Mixing Ratio: Aqueous Batch test

  • Oh, Seung Min;Oh, Se Jin;Kim, Sung Chul;Lee, Sang Hwan;Ok, Yong Sik;Yang, Jae E.
    • Korean Journal of Soil Science and Fertilizer
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    • v.47 no.6
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    • pp.540-546
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    • 2014
  • Acid mine drainage sludge (AMDS) has been classified as mine waste and generally deposited in land. For this reason, studies have been conducted to examine the possibility of recycling AMDS as an amendment for heavy metal stabilization in soil. The main objective of this study was to evaluate heavy metal stabilization efficiency of AMDS comparing with the widely used lime stone. Also, optimum mixing ratio was evaluated for enhancing heavy metal stabilization. AMDS and limestone were mixed at the ratio of 0:100, 25:75, 50:50, 75:25, and 100:0 with five different heavy metal solutions ($100mg\;L^{-1}$ of $NaAsO_2$, $CdCl_2$, $CuCl_2$, $Pb(NO_3)_2$, and $ZnSO_4{\cdot}7H_2O$). The amendments were added at a rate of 3% (w/v). In order to determine the stabilization kinetics, samples were collected at different reaction time of 0, 1, 2, 4, 8, 16, 32, 64, 128, 256, 512, 1024 minutes. The heavy metal stabilization by AMDS was faster and higher than those of limestone for all examined heavy metals. While limestone showed only 20% of arsenic (As) stabilization after 1,024 minutes, 96% of As was stabilized within 1 minute by AMDS. The highest effect on the stabilization of heavy metal (loid) was observed, when the two amendments were mixed at a ratio of 1:1. These results indicated that AMDS can be effectively used for heavy metal stabilization in soil, especially for As, and the optimum mixing ratio of AMDS and lime was 1:1 at a rate of 3% (w/v).

Synthesis of Alinite-Calciumchloroaluminate System Cement Using Solid State Waste

  • Cho, Jin-Sang;Han, Gi-Chun;Kim, Hyung-Seok;Ahn, Ji-Whan;Kim, Hwan;Lee, Hyoung-Ho
    • Proceedings of the IEEK Conference
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    • 2001.10a
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    • pp.581-585
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    • 2001
  • Alinite-Calciumchloroaluminate system clinker was synthesized from solid state waste. The raw materials were municipal incineration ash, sewage sludge, limestone and clay. ecocement was prepared by the mixing of synthesized clinker and optimum amount of gypsum and its hydrolysis characteristic was investigated. X-ray diffraction, conduction calorimeter and reflecting microscope were used to analyze structural and physical properties. The main phase of clinker were alinite, calcium chloroaluminate. $C_2$S, $C_3$S. From the results of hardening time, hydration reactivity of synthesized all samples was faster than that of ordinary portland cement.

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Investigation on the Ratio and Type of Gypsum for Early Strength Improvement of Blast Furnace Slag Powder (고로슬래그 미분말의 초기강도 향상을 위한 석고 종류 및 첨가량 검토)

  • Jeong, Yong;Yoo, Jung-Hoon;Shin, Jae-Kyung
    • Journal of the Korean Recycled Construction Resources Institute
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    • v.5 no.4
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    • pp.106-113
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    • 2010
  • We were tried to draw a conclusions related to additive amount of gypsum in blast furnace slag in the study. In the result, fluidity of concrete decreased with an increase of gypsum and was not satisfied with KS standard in the cases of natural gypsum and limestone sludge more than 2.6% addition. Early compressive strength of concrete containing desulfurized gypsum, fluosilicic acid gypsum and phosphoric acid gypsum were improved respectively but calcined lime sludge and lime powder were not influenced on strength. If available, additive gypsum should be managed less than 2.0% owing to low fluidity. In low temperature, fluosilicic acid gypsum was to advantages on the fluidity while desulfurized gypsum was in high temperature. There also are conclusions that additive gypsum was to be 2.6% in winter and in summer; it's to be fewer than 2.6%.

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The Properties of Synthetic Calcium Ferrite for Ironmaking and Steelmaking using Industrial By-products - (1) (산업부산물을 활용한 제철·제강용 합성 칼슘 페라이트 특성 - (1))

  • Park, Soo Hyun;Chu, Yong Sik;Seo, Sung Kwan;Park, Jae Wan
    • Resources Recycling
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    • v.23 no.5
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    • pp.3-11
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    • 2014
  • Calcium ferrite is more effective binder for making sintered ore and flux for steel making because of it's low melting temperature. In this Study, calcium ferrite was made by calcinating method in the cement manufacturing process in order to reduce manufacturing costs and increase productivity. Limestone and calcination sludge were used as CaO source, steelmaking sludge, blast furnace dust and iron ore were used as Fe-bearing raw materials. The sintering temperature of specimens is in the range of $950{\sim}1170^{\circ}C$. For Calcium ferrite can be used 'binder for making sintered ore' or 'flux for converter/electric furnace' with a low melting point properties, the raw material characteristics and sintering properties were investigated.

Recovery of Acids and Valuable Metals from Stainless-Steel Pickling Acids (스텐레스 산세폐액으로부터 산 및 유가금속의 회수)

  • 김성규;이화영;오종기;이동휘
    • Resources Recycling
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    • v.1 no.1
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    • pp.23-28
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    • 1992
  • The process for recovery of acids and valuable metals such as nickel and chromium from the stainless-steel pickling acids has been developed vased on the use of solvent extraction technique. Until now, several processes for the treatment of waste acids were already developed in such countries as Japan, Swden and Canada. Those methods are, however, forcussed on the recovery of acids from them discarding the metals included in them as the hydroxides sludge. In the present work, the recovery of nickel and chromium in addition to nitric acid and hydrofluoric acid has been aimed so as to recycle them to the stainless-steel pickling lines and also to minimize the amount of sludge generated during the treatment of waste acids. The establishment of the process to recover the acids has been carried out based on the solvent extraction with TBP. The iron was eliminated from the waste solutions by precipitating in the form of hydroxide through the adjustment of pH with calcined limestone and the selective extration of chromium and nickel from the resultant solutions has been conducted by using D2EHPA as extractant.

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Treatment of Industrial Wastes by Melting Using H.F. Induction Furnace (고주파 유도로를 이용한 산업 폐기물의 용융처리)

  • 정진기;정헌생;이재천;윤인주;남기대
    • Resources Recycling
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    • v.6 no.1
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    • pp.23-28
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    • 1997
  • Iron and slag were prepared by melting mixed industrial wastes in an induction furnace. The wastes were steel can, limestone sludge, waste foundry sand, coal fly ash, and glasses. The effects of their mixing ratio on the charactenstics of the meltcd slag were investigated. The wastes were melted to slag under the constant basicity of 1.2. It was found that the major phases of the slag were P-C,S and C,AS and then ratio was determined by the mixing ratio af waste materials. The recovery of iron was about 93-95%. The feasibility of using the slag as the aggregate was confirmed by thc elution and campression tests.

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Leaching Properties of Water-Soluble Hexavalent Chromium by Manufacturing Condition of Cement Clinker (클링커 제조 조건에 따른 수용성 6가 크롬 용출 특성)

  • Lee, Jong-Kyu;Chu, Yong-Sik;Song, Hun
    • Korean Journal of Materials Research
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    • v.21 no.12
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    • pp.679-684
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    • 2011
  • One of the trace constituents included in cement clinker, chromium, has become prominent and highly noticed lately as a social issue both inside and outside of this country because it affects the human body negatively. The purpose of the present study was to investigate leaching properties of water-soluble hexavalent chromium by different manufacturing conditions of cement clinker. Raw materials were prepared to add different $SiO_2$, $Al_2O_3$ and $Fe_2O_3$ sources. After the raw materials, such as limestone, sand and clay, iron ore was pulverized and mixed, and the raw meal was burnt at $1450^{\circ}C$ in a furnace with an oxidizing atmosphere. Leaching of soluble hexavalent chromium showed a tendency to decrease with an increasing LSF and IM. However, leaching of soluble hexavalent chromium increased with an increasing S.M. Alkali contents of iron source minerals is closely related to the leaching properties of soluble hexavalent chromium. Green sludge has the highest content of alkali added; leaching of water-soluble hexavalent chromium was mostly high. In order to reduce the water-soluble hexavalent chromium in cement, reducing the alkali content in raw materials is important.

The Recycling of Inorganic Industrial Waste in Cement Industry (시멘트산업에서 무기질 산업 폐·부산물의 재활용)

  • Kang, S.K.;Nam, K.U.;Seo, H.N.;Kim, N.J.;Min, K.S.;Chung, H.S.;Oh, H.K.
    • Clean Technology
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    • v.6 no.1
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    • pp.61-69
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    • 2000
  • In this study, generation process and properties of inorganic industrial waste which can be used in cement industry were investigated. The scheme of recycling to use the selected waste as raw materials, mineralizer and flux, admixture and raw materials for special cement was decided and then various experiments were carried out. The experimental results were as follows ; In the use of industrial waste as raw materials, ferrous materials could be substituted by Cu-slag, Zn-slag, electric arc furnace or convertor furnace slag etc., and a siliceous material could be substituted by sand from cast-iron industry. By-products from sugar or fertilizer industry, which has $CaF_2$ as the main component, and jarosite from Zn refinery enabled clinker phases to be formed at lower temperature by $100{\sim}150^{\circ}C$. Adding Cu slag and STS sludge in proper proportion to cement improved properties of cement. Fly ash and limestone powder as admixture had the same effect on cement. As a raw material for special cement, aluminium waste sludge could be used in making ultra early strength cement, which had the compressive strength of $300kg/cm^2$ within 2hours. And two different ashes from municipal incinerator could be raw materials of the cement which was mainly composed of $C_3S$ and $C_{11}A_7{\cdot}CaCl_2$ as clinker phases.

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Stabilization of Arsenic in Soil around the Abandoned Coal-Mine Using Mine Sludge Pellets (광산슬러지 펠렛을 이용한 폐석탄광 주변 토양 내 비소 안정화 연구)

  • Ko, Myoung-Soo;Ji, Won-Hyun;Kim, Young-Gwang;Park, Hyun-Sung
    • Economic and Environmental Geology
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    • v.52 no.1
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    • pp.29-35
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    • 2019
  • The purpose of this study was to assess the applicability of acid mine drainage sludge (AMDS) pellets for the arsenic (As) stabilization and to suggest an evaluation method for arsenic stabilization efficiency in soil around abandoned coal mines. The soil samples were collected from the agricultural field around Ham-Tae, Dong-Won, Dong-Hae, and Ok-Dong coal mine. The As concentration in soil was exceeding the criteria of soil pollution level, except for Ham-Tae coal mine. The AMDS pellets are more appropriate to use by reducing dust occurrence during the transport and application process than AMDS powder. In addition, AMDS pellets were maintained the As stabilization efficiency. The application of AMDS pellets for the As stabilization in soil was assessed by column experiments. The AMDS pellets were more effective than limestone and steel slag, which used as the conventional additives for the stabilization process. The As extraction by $0.43M\;HNO_3$ or $1M\;NaH_2PO_4$ solution were appropriate evaluation methods for evaluation of As stabilization efficiency in the soil.