Despite technological developments, modern methods for the disposal of end-of-life tires most often involve either their incineration in cement kilns or the destruction of tires in special landfills, demonstrating a lack of sustainable recycling of this valuable material. The fundamental role of recycling is evident, and the development of high-efficiency processes represents a crucial priority for the European market. Therefore, the investigation of end-of-life rubber processing methods is of high importance for both manufacturers and recyclers of rubber materials. In this paper, we review existing methods for processing of end-of-life tires, in order to obtain rubber crumb, which can later be used in the production of new industrial rubber goods and composites. We consider processes for separating end-of-life tires into fractions (in terms of types of materials) using chemical, mechanochemical, and mechanical methods to process the materials of used tires, in order to obtain crumb rubber of various fractions and chemical reactivities.
In spite of the critical environmental impacts of mining and the associated geopolitical supply risk, the strategic importance of rare metal tungsten is escalated by rapid expansions in industrialization, particularly in the ongoing low-carbon/energy era, which requires technologies that allow an economic, social, and ecologically friendly tungsten recovery from primary and secondary resources. The current recycling practices of tungsten carbide (WC)-based scraps have been accepted as economically and partially environmentally beneficial and can promote tungsten closed-loop recycling; however, low functional recycling rates and significant metal losses at varied stages hinder the economic recovery of metals. The current review presents the global situation of tungsten and WC flow with a focus on various sustainable methods to recycle spent tungsten and related metals. A detailed discussion of establishing a highly resilient circular economy with sustainable development goals is highlighted by juxtaposing the philosophy of the circular economy, integrated sustainability, and the metal life cycle approach. The article also discusses Industry 5.0 trends, such as sustainable digitalization and twin transition, to overcome the barriers associated with achieving efficient circular recycling. It is shown that cross-disciplinary methodologies, the integration of diverse technologies (digital/green), and the incorporation of state-of-the-art recycling techniques open up the future potential in the recycling sector.
1 January 2020 in International Journal of Refractory Metals and Hard Materials
Circular economy and recycling of post-consumer textile waste is gaining momentum. Its major obstacle is low-quality recycled products. This review article analyses commercial post-consumer textile materials, their recycling and applications. Modernization of fibre processing and recycling technology has assumed an indispensable role in the quality enhancement of post-consumer products. A futuristic overview of fabric materials, their processing, recycling and applications is presented by the example of commercial polymers. Different types of recycling â primary, secondary, tertiary, quaternary, and biological â used with ultramodern compatibilization and cross-linking are explored. Additionally, the conventional and proposed âJust-in-Timeâ (JIT) remanufacturing and recycling technologies for enhancing circular economy are demonstrated.