"Recycled-Waste Cement Not Linked to Hazard Concerns"

No Correlation Observed Between Recycled-Resource Content and Hazardous Substances or Odors
Boost Community Acceptance Through Cooperation Between Local Governments and the Cement Industry

An analysis has found that cement made using waste as a raw material or fuel is not associated with hazards such as odors or pollutants, and that it helps reduce social costs, including by cutting greenhouse gas emissions. Experts say solutions must be sought through cooperation with local communities to address stricter environmental regulations on hazardous substance emissions and dispel negative perceptions among residents living near kilns.

At a special session on cement at the fall conference hosted by the Korean Society of Waste Management at Sono Calm Gyeongju on November 12, Professor Kim Jinman of Kongju National University said that results verified by Korea Conformity Laboratories showed that “there is no link between the use of recycled resources in cement and whether it is hazardous.” The verification compared the emission characteristics of products from seven domestic cement plants with those of products from three other countries: Japan, China, and Switzerland.

Professor Kim Jinman of the Department of Green Smart Architectural Engineering at Kongju National University presenting at the cement session of the Fall Academic Conference of the Korea Society of Waste Management and Resource Recycling, held at Sono Calm Gyeongju on the 12th. Korea Society of Waste Management and Resource Recycling

"No Evidence of Hazards from Using Recycled Resources"

Professor Kim said the verification found no hexavalent chromium or major toxic heavy metals, including lead, cadmium, and arsenic, in any of the cement samples. Copper was detected in trace amounts, but at less than 3% of the comparative benchmark, and no hazard was identified, he said. The results showed no clear link to support concerns that higher recycled-resource content would lead to higher levels of hazardous substances.

Professor Kim said that during cement production, no trend was observed toward increased odors or pollutant emissions as the recycled-resource content ranged from 16% to 27%. Some substances, including ammonia, showed a negative correlation. “The results of the joint public-private investigation led by the Ministry of Climate were similar to those of this study: there was no evidence that domestic products consistently emitted more pollutants than overseas products,” he said.

Cement Made with Recycled Resources Shows No Decline in Quality 

A separate analysis found that using recycled resources as fuel in cement production helps reduce social costs because it contributes significantly to cutting greenhouse gas emissions. At a presentation of the study “Feasibility of Using Combustible Waste to Replace Bituminous Coal in Cement Kilns,” a research team from the Sejong Institute of Science and Technology, led by Dr. Kim Dongchan, analyzed the differences in hazardous substance generation between combustion in cement kilns and ordinary combustion.

The research team said it had found no cases of lower-quality cement produced using recycled resources. “A regression analysis of 340 cases from one domestic cement company found that the amount of alternative fuel used had no significant effect on the chemical composition or mineral composition of clinker, and compressive strength did not decline,” the team said.

Dr. Kim Dongchan said that cement kilns, which are production facilities, have a heat utilization rate of 100%, higher than the 30% to 40% rate of small- and medium-sized incinerators, and thus help reduce greenhouse gas emissions. In 2024, of the total 23.85 million tonnes of combustible waste generated at domestic businesses, 2.87 million tonnes, or 12%, were used in cement kilns as fuel to replace bituminous coal. Of this amount, waste synthetic resins, including waste plastics and waste vinyl, accounted for about 90%. Recycled resources currently replace about 35% of the bituminous coal used in Korea, reducing carbon dioxide emissions by 5 million tonnes annually. If the rate rises to 70%, as in Europe, annual reductions are expected to reach 10 million tonnes.

Dr. Kim Dongchan of the Sejong Institute of Science and Technology presents his study, “A Feasibility Study on Using Combustible Waste as a Substitute for Bituminous Coal in Cement Kilns,” at Sono Calm Gyeongju on the 12th. Photo by Han Jinju.

Boosting Community Acceptance Through Cooperation with Local Residents

Another recommendation was to expand the use of recycled resources through cooperation with local communities. A research team led by Professor Kim Seokwan of Daegu Haany University and Professor Yeon Ikjun of Korea National University of Transportation emphasized the need to establish a cooperation system involving cement plants, local governments, and residents in a presentation titled “Cooperation Measures for Using Waste Resources in the Cement Industry.” The team also proposed a “3+1 hybrid model” as an alternative. Under a “three-party agreement” involving the local government where the waste is generated, the local government where the cement plant is located, and the cement company, the parties would establish a process for prior consultation and community acceptance. The team said that a four-party agreement including solid recovered fuel (SRF) pretreatment and supply companies could also share responsibility for quality assurance and penalties.

The team proposed a cost-sharing structure in which the local government where the waste is generated pays the waste-treatment outsourcing fee, while the local government where the plant is located pools the funds and uses them for initiatives such as local residents’ health surveys. Cement companies could expand the scope of their social contribution funds and work with local communities to support energy welfare for residents, including district heating, and invest in environmental improvements. Overseas, including in Europe and Japan, the use of recycled resources is being expanded through waste treatment contract fees, tax contributions, and community funds.

Professor Kim Seokwan said, “To foster cooperation, the existing system of permits for waste deliveries needs to be replaced with an agreement-based system for accepting waste, with transparent public disclosure of information and verification.” He added, “The government should also create a sustainable cycle for reducing carbon emissions by easing regulations for companies with strong carbon-reduction records, providing financial support to local governments where production facilities are located, and using the funds secured for reinvestment in local communities and support for residents.”

This content was produced with the assistance of AI translation services.