Hydration and leaching characteristics of cement pastes made from electroplating sludge

Journal Article · Wed Jun 15 04:00:00 EDT 2011 · Waste Management

DOI:https://doi.org/10.1016/j.wasman.2010.12.018· OSTI ID:21550381

Chen, Ying-Liang ^[1]; Ko, Ming-Sheng ^[2]; Lai, Yi-Chieh ^[3]; Chang, Juu-En ^[1]

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1. Department of Environmental Engineering, National Cheng Kung University, No. 1, University Rd., Tainan City 70101, Taiwan (China)
2. Institute of Mineral Resources Engineering, National Taipei University of Technology, No. 1, Sec. 3, Chunghsiao E. Rd., Taipei City 10608, Taiwan (China)
3. Department of Bioenvironmental Engineering, Chung Yuan Christian University, No. 200, Chung-Pei Rd., Chung-Li 32023, Taiwan (China)

The purpose of this study was to investigate the hydration and leaching characteristics of the pastes of belite-rich cements made from electroplating sludge. The compressive strength of the pastes cured for 1, 3, 7, 28, and 90 days was determined, and the condensation of silicate anions in hydrates was examined with the {sup 29}Si nuclear magnetic resonance (NMR) technology. The leachabilities of the electroplating sludge and the hardened pastes were studied with the multiple toxicity characteristic leaching procedure (MTCLP) and the tank leaching test (NEN 7345), respectively. The results showed that the electroplating sludge continued to leach heavy metals, including nickel, copper, and zinc, and posed a serious threat to the environment. The belite-rich cement made from the electroplating sludge was abundant in hydraulic {beta}-dicalcium silicate, and it performed well with regard to compressive-strength development when properly blended with ordinary Portland cements. The blended cement containing up to 40% the belite-rich cement can still satisfy the compressive-strength requirements of ASTM standards, and the pastes cured for 90 days had comparable compressive strength to an ordinary Portland cement paste. It was also found that the later hydration reaction of the blended cements was relatively more active, and high fractions of belite-rich cement increased the chain length of silicate hydrates. In addition, by converting the sludge into belite-rich cements, the heavy metals became stable in the hardened cement pastes. This study thus indicates a viable alternative approach to dealing with heavy metal bearing wastes, and the resulting products show good compressive strength and heavy-metal stability.

• OSTI ID: 21550381
• Journal Information: Waste Management, Journal Name: Waste Management Journal Issue: 6 Vol. 31; ISSN WAMAE2; ISSN 0956-053X
• Country of Publication: United States
• Language: English

Related Subjects

12 MANAGEMENT OF RADIOACTIVE AND NON-RADIOACTIVE WASTES FROM NUCLEAR FACILITIES
36 MATERIALS SCIENCE
ALKALINE EARTH METAL COMPOUNDS
ANIONS
BUILDING MATERIALS
CALCIUM COMPOUNDS
CALCIUM SILICATES
CEMENTS
CHARGED PARTICLES
COMPRESSION STRENGTH
CONTAINERS
COPPER
DEPOSITION
DISSOLUTION
ELECTRODEPOSITION
ELECTROLYSIS
ELECTROPLATING
ELEMENTS
ENVIRONMENTAL IMPACTS
EVEN-ODD NUCLEI
HEAVY METALS
HYDRATES
HYDRATION
IONS
ISOTOPES
LEACHING
LIGHT NUCLEI
LYSIS
MAGNETIC RESONANCE
MATERIALS
MECHANICAL PROPERTIES
METALS
NICKEL
NUCLEAR MAGNETIC RESONANCE
NUCLEI
OXYGEN COMPOUNDS
PLATING
PORTLAND CEMENT
RESONANCE
SEPARATION PROCESSES
SILICATES
SILICON 29
SILICON COMPOUNDS
SILICON ISOTOPES
SLUDGES
SOLVATION
STABILITY
STABLE ISOTOPES
SURFACE COATING
TANKS
TOXICITY
TRANSITION ELEMENTS
WASTES
ZINC