## 1 Introduction
Specifically, China led with 27.3%, followed by the United States (16.3%), and the EU-27 (20.5%), within which Germany, Italy, Sweden, Finland, and France were the top producers. In Latin America, Brazil and Uruguay also stood out, with Brazil's production exceeding 10 million tons, supported by its rapidly growing eucalyptus-based pulp industry [11]. This production reflects the widespread availability of cellulose as a secondary material, which can be recycled and used in new manufacturing contexts. Mining tailings, which are the waste materials remaining after the processing and separation of the valuable fractions of an ore, are generated in the range of 5-7 billion tons per year throughout the world. This vast quantity of tailings presents significant environmental challenges and opportunities for reuse. In China alone, over 4.5 billion tons of industrial solid waste were produced in 2018, with a significant share corresponding to mining tailings. Additionally, Brazil has been a focus of international attention due to the Brumadinho disaster in 2019, which underscored the environmental risks associated with poor tailings management [12]. In the case of slags, according to statistics, just from steel slag alone, the world produces about 190 to 290 million tons every year. China stands out as the largest producer, with around 80 to 90 million tons annually, followed by India, which generated nearly 40 million tons between 2017 and 2018 [13]. In the European Union, countries such as Germany and the United Kingdom are actively promoting slag valorization; for example, in the UK, steel slag is already used as an aggregate in concrete and asphalt mixtures. However, in many regions the reuse rate remains low, highlighting the need for improved recovery strategies to enhance circularity in the construction sector, since much of this by-product is either left in open-air stockpiles or disposed of in landfills. These data clearly demonstrate that these materials are generated in vast quantities globally, with millions of tons produced annually, posing serious environmental challenges but also presenting substantial opportunities for reuse within the construction industry. Their reuse can significantly reduce the reliance on virgin materials, decrease landfill use, and promote greater resource efficiency. Sourced from segments like paper manufacturing, agricultural production, the textile industry, and wastewater treatment plants, cellulose waste offers unique characteristics that are ideal for various building materials [14; 15]. In the paper industry, cellulose waste mainly originates from the sludge produced during papermaking. This sludge is rich in high-quality cellulose fibers, which are increasingly being repurposed to manufacture eco-cement [16], insulation panels, and fiberboards [17]. These products are prized for their excellent thermal and acoustic properties, aligning well with modern building standards that prioritize energy efficiency. Agricultural residue, such as straw, hemp, and bagasse, also serves as valuable sources of cellulose waste. These materials can be transformed into composites used for wall panels, roofing, and flooring solutions, leveraging their lightweight and durable nature for eco-friendly construction projects [18]. For example, hempcrete, a composite made from hemp fibers and lime, is renowned for its sustainability, excellent thermal insulation, and moisture-regulating properties, making it a superior alternative to conventional building materials [19]. Additionally, textile waste, particularly from cotton and linen, provides another substantial source of cellulose. Recycled fabrics can be processed into fibers that enhance the mechanical properties of concrete, such as tensile strength and durability, thereby extending the lifespan of concrete structures and contributing to more sustainable construction practices [20]. In addition to the applications mentioned for cellulose waste, mining tailings are also finding a valuable place in the construction industry.