**1. Introduction**

The United Nations have ratified 17 goals of sustainable development, of which responsible consumption and production is directly, while economy, innovative industry, infrastructure, and climate action are indirectly related to circular economy and the need of sustainable production [1]. Sustainability in the processing industries can be applied along the main value chain, e.g. from metal extraction to metal recycling, but can also be applied to the associated waste materials. Copper and iron mining alone are estimated to generate yearly about 5 bn tons of tailings [2], i.e. the fraction of the processed ore, after extraction of the valuable minerals. Finding a way to successfully reuse vast amount of this material and other waste sources is a great step towards circular economy.

While recycling an initial waste or side-stream, the material can be upcycled, meaning the newly derived product is of higher intrinsic value and properties or downcycled, where the new material has lower value. A prominent example for downcycling is the reuse of plastic bottles as fleece and carpet material. The material has less intrinsic value, because the carbon chains of the plastic polymer are shortened. Geopolymerization of industrial side streams is an upcycling process, as the geopolymer (GP), utilized as concrete and binder, has a higher value than the initial industrial by-products. To obtain upcycling, energy is put into the system, however, since tailings have usually been milled, the material has already undergone energy intensive steps and can therefore readily be used as starting blocks for geopolymerization. Utilizing tailings for upcycling into GPs, is therefore beneficially in terms of waste management, process energy, and emission of greenhouse gases, as the energy used in the beneficiation process is passed onwards into the geopolymerization process. Upcycling often requires further energy sources to achieve higher valuable material. In geopolymeration or alkaline activation this means the addition of chemicals, and in some occasions, such as analcime tailings, the addition of thermal energy [3].

In this chapter the valorization of high volume, inorganic side streams from mining, chemical industries, steel processing, and waste incineration into new adsorbents useable for water treatment is discussed. The purpose is to show how the material undergoes value change from side stream to potentially highly functional material.

As every tailing and every ash has a different chemical and mineral composition, tailoring of the properties of resulting adsorbents is possible by careful choosing of precursor materials. Aluminosilicates form the backbone of the geopolymer structure, but ion exchange, channel size, and physical properties are affected by the minerals used for geopolymerization [4–6]. Lastly, by controlling of the geopolymerization conditions, also the macroscopic structures can be developed by using various manufacturing methods from foaming to granulation.

The ultimate goal of using GPs/AAMs in water purification is to be able to recover valuable materials such as nutrients or battery chemical metals from contaminant-rich wastewater streams. In other words, the target is to use one industrial side stream to recovery of valuable material from another side stream or waste water in order to multiply circular economy potential.
