This project belongs to the field of comprehensive utilization of solid waste, involving key technologies and application suites for producing green and energy-saving wall materials from urban sludge. It also falls within the category of energy-saving building materials. Each year, a huge amount of urban sludge is discharged due to complex origins, high organic matter content, and local environmental safety risks. This leads to simple and extensive disposal, low resource utilization rates, and severe environmental pollution, which are urgent issues that need to be resolved. In response to these technical challenges and the significant demand for energy-saving wall materials in urban construction, the project team, with support from national science and technology programs, the National 863 Program, the National Natural Science Foundation, and other projects, has researched and invented a series of products and technologies with independent intellectual property rights that cover the entire industrial chain from urban sludge safety assessment and treatment methods to the production of green and energy-saving wall materials, as well as the application of sludge energy-saving product systems. These have been widely promoted and applied in numerous projects. The project has achieved energy-saving and efficient recycling of urban sludge, with the main technical innovations including: 1. Urban Sludge Environmental Safety Assessment and Pre-treatment Technology. ① To address the widespread distribution and significant variability of urban sludge, a physical and chemical characteristic map and environmental safety distribution chart for urban sludge in the Shanghai area were constructed; ② To tackle the issue of heavy metal exceeding standards in some areas of sludge, an electric method and device for removing heavy metals from urban sludge were invented, effectively controlling environmental safety; ③ To resolve problems such as uneven impurities, high organic matter content, and high water content in urban sludge, pre-treatment technologies, processes, and devices suitable for energy-saving product production were developed, which effectively solved the technical difficulties of high drying energy consumption and unstable quality of sintered products. 2. Key Technologies for High-Temperature Sintering of Urban Sludge to Produce Lightweight Energy-Saving Wall Materials. ① In response to the traditional coal combustion problem of large carbon emissions and severe pollution, Invention of key technologies for 100% substitution of rice husk biomass fuel for coal direct combustion into sludge products, reducing production energy consumption and carbon emissions; (2) In response to the contradiction between urban construction's demand for energy-saving wall materials and city bans on adhesives, invention of design, preparation, production, and firing techniques for 100% substitution of urban sludge for clay in the preparation of self-insulating sintered porous bricks; (3) Addressing the challenge of high sand content and organic matter in urban sludge, invention of a new method for sludge lightweight ceramic granule expansion and key technologies and equipment for sludge lightweight ceramic granule production, solving the problems of difficulty in expanding urban sludge and waste heat recovery; development of efficient insulation sludge ceramic granule lightweight block production technology; (4) For the variability of components in urban foundation pit sludge, development of quality control, green body 'low temperature high humidity' drying, and firing techniques for preparing sintered porous bricks from building foundation pit sludge; (5) In response to the characteristics of other types of solid waste in cities, a key technology for co-disposal of urban sludge with other solid waste to produce energy-saving sintered porous bricks or ceramsite has been invented. III. Key technologies applied in the urban sludge energy-saving product system. 1) Design and application of a complete set of key technologies for an urban sludge lightweight self-insulating system that achieves a building energy efficiency rate of 65%; 2) In response to the problems of easy floating of ceramsite in lightweight concrete and significant loss of workability, a pumpable admixture and application technology for controlling the loss of slump in ceramsite concrete have been invented, achieving ultra-high pumping of lightweight sludge ceramsite concrete; 3) In view of the scarcity of natural stone resources in cities, a key technology has been developed to use urban sludge ceramsite as the main base material to create environmentally friendly artificial cultural stone decorative products. 16 utility model patents have been authorized, 9 utility model patents have been applied for, and 2 invention patents have been applied for; Editor-in-Chief or Co-editor of 3 national standards and specifications, co-editor of 4 industry or local standards and specifications; published 56 papers in core domestic and international journals, including 16 papers indexed by SCI and EI. The achievements of multiple special projects have been appraised as reaching the international advanced level. The energy-saving products such as silt self-insulation sintered porous bricks have obtained 23 honors including Shanghai Patent New Product, Energy-saving Product, and Comprehensive Resource Utilization Certification. The results have been mass-produced in multiple companies and widely applied in key projects of Shanghai, Fujian, Zhejiang, and other provinces and cities, generating significant economic, social, and environmental benefits. From 2011 to 2013, a total of 1.23 billion yuan in added value was generated.