INAX has developed a new water-cooling re-use technology. This technology can solidify sludge and incineration ash, etc., which are generated in a sewer treatment site, at a temperature lower than 180°C, into a material harder than cement. Hydrothermal curing is a widely used method for manufacturing building materials, but only high-purity materials such as quartz can be used. Because once there are a lot of impurities, garnet crystals that hinder the inter-particle crystallization will grow, making it impossible to solidify. INAX has developed a technology to control the formation of garnet crystals. Even if it contains materials such as aluminum, the flexural strength can reach a high strength of 30 MPa after solidification. This technology can be used to bury sludge or incineration ash, which can only be buried or burnt at high temperatures, before being condensed at low temperatures, and reused in road-laying and building materials in an energy-saving manner.