CIBAA® Cold Bonding Process

CIBAA® is Day Group’s proprietary technology for upgrading selected fractions of Incinerator Bottom Ash Aggregate (IBAA). It uses a low-energy cold bonding process to improve aggregate robustness, grading consistency, handling characteristics and environmental performance.

Development and Intellectual Property

The process was conceived and developed by Dr Noel Djobo, Product Development Manager at Day Group, as part of the company’s continuing research into mineral processing, aggregate conditioning and low-carbon construction materials.

In February 2026, the project received competitive Innovate UK funding to support proof-of-concept development, technical validation and feasibility demonstration.

The technology is the subject of UK Patent Application GB2609811.1. It combines controlled moisture conditioning with proprietary binder chemistry in a continuous process designed to integrate with conventional IBAA production infrastructure. A pilot-scale treatment line is in operation, and the next stage is planned at Day Group’s Wellingborough facility.

Process Overview

CIBAA® treatment focuses principally on fine and sub-fine IBAA fractions that can significantly affect aggregate behaviour. The process comprises:

• Controlled addition of a proprietary calcium-based mineral binder
• Addition of CO2-activated water generated on site
• Continuous intensive mixing to promote agglomeration, stabilisation and particle interaction
• Short-term curing under normal stockpiling conditions

The resulting material remains workable during handling and blending while offering improved resistance to physical breakdown and more consistent engineering performance.

Demonstrated benefits

Development trials have demonstrated that the Day Group Ltd cold bonding process can:

• Transforms fine-rich IBAA feedstocks into a coarser conditioned aggregate product, with up to 70% reduction in fine particles, supporting improved handling and more consistent use in sub-base and capping applications
• Create stable engineered mineral phases, including calcium carbonate and calcium-aluminium hydrated phases associated with improved contaminant-release performance
• Improve multi-contaminant release performance, including lower initial leachate alkalinity and reduced release of contaminants such as copper and total chromium under defined test conditions
• Produce defined conditioned aggregate products through a continuous and commercially practical process.

CIBAA® therefore provides a practical, non-thermal route for transforming IBAA into defined conditioned aggregate products with improved physical characteristics and environmental performance, supporting resource efficiency and wider circular economy objectives.