학술논문

Recycling of calcium fluoride sludge as ceramic material using low temperature sintering technology
Document Type
Brief Communication
Source
Journal of Material Cycles and Waste Management: Official Journal of the Japan Society of Material Cycles and Waste Management (JSMCWM) and the Korea Society of Waste Management (KSWM). February 2014 16(1):156-161
Subject
Calcium fluoride sludge
Solidifying
Low temperature sintering
Recycling
Language
English
ISSN
1438-4957
1611-8227
Abstract
The Chinese integrated circuit industry has been transformed from a small state-owned sector into a global competitor, but chip manufacturing produces large amounts of calcium fluoride sludge (CFS). The current treating method is landfill in China. In order to solve the problem of unavailable landfill sites and the dissolved CFS polluting water sources, CFS was tested as a component for a ceramic product made with sodium borate, sodium phosphate, and waste alumina using a low temperature sintering technology. The ceramic was characterized by X-ray diffraction (XRD), microstructure, compressive strength. XRD and microstructure analyses verified that CFS was transformed into Na2Ca(PO4)F as an inert crystalline phase in ceramic, which is enclosed by the borophosphate glass liquid phase. Toxicity characteristic leaching procedure and corrosion resistance tests verified that fluorine from CFS was solidified in the inert crystalline phase, which did not release to cause secondary pollution. This novel technology produces high-performance ceramic as a construction material, in accordance with the concept of sustainable development.