Scrap to Cement
The Korea Environmental Industry & Technology Institute and the R&D Center for Valuable Recycling announced on March 11 that they developed a technique to produce fast-setting cement based on the rapid cooling of liquid-phase ladle furnace slag that is generated when scrap metal is turned into iron.
Fast-setting cement, which is used in emergency road recovery, underwater concrete works, and the like, is cured in three to seven hours. The period is at least 20 days for cement in general.
Korea buries approximately 720,000 tons of ladle furnace slag a year, which has resulted in environmental pollution in the form of dust and contaminated leachate. However, the new technique is expected to reduce pollution while taking the place of the high-temperature processes for existing fast-setting cement production techniques. Carbon dioxide emissions could decrease by about 500,000 tons a year.
The institute explained that 4.3 billion won (US$3.8 million) could be saved in slag treatment costs, and fast-setting cement worth 288 billion won (US$254 million) can be produced when 720,000 tons of ladle furnace slag is turned into fast-setting cement. If so, the domestic cement industry’s dependence on imported fast-setting cement can be dropped from over 80 percent to nothing.
“The new technique will lead to the supply of fast-setting cement worth 6.8 trillion won [US$6.0 billion] worldwide, given that a total of 17 million tons of ladle furnace slag was produced last year,” the institute said.