In the beginning, the researchers only had gold and tights - in an interview with Tekniikan maailma, Ari Väisänen, one of the founders of Weeefiner, tells about the birth of the 4D Scavenger® technology.
"Me and my research colleagues were looking for materials that could recover precious metals from waste streams. We tested different compounds and noticed that a certain type of nylon was selective for gold", says Ari Väisänen. Väisänen works as a professor of analytical chemistry and circular economy at the University of Jyväskylä. He is one of the founders of Weeefiner, the company that commerzialiced the 4D Scavenger® and he has been involved in the development of 4D Scavenger® from the beginning.
Opposed to nylon, scientists also tested pantyhouse for capturing gold, but they did not work quite as effeciently. The golden idea of 3D printing the nylon into practical filters eventually led to the birth of the 4D Scavenger® technology.
4D Scavenger® technology captures metals in ion form, i.e. in dissolved form. The filter compound has either a positive or negative charge that attracts oppositely charged metal ions. Similar method is used, for example, in ion exchange resins.
4D Scavenger's differences come from its unique manufacturing method. 3D printed filter-like units appear solid, but they are porous throughout. It makes the process much more efficient and facilitates the recovery and washing of raw materials from the filter. You can also change the active material depending on which ions you want to stick to the filters. Different compounds can capture different materials.
"Initially, we were interested in gold and palladium and rare earth metals. Since then, we have captured everything all the way from nutrients," says Väisänen.
The goal of 4D Scavenger® is to solve the problems of traditional methods, such as reaction slowness and poor selectivity. With the help of scavengers, metals present in even low concentrations can be accurately and selectively captured from process and waste streams. Once the metals are recovered, they can be further refined or reused. This opens up new opportunities for a practical circular economy.
Read the whole story from Tekniikan maailma (available in Finnish): Ensin tutkijoilla oli kultaa ja sukkahousut
Weeefiner Ltd. was founded in 2017 to manage the 4D Scavenger® technology patent and to continue technology development. The pilot use of 4D Scavenger® in
authentic environments began at the end of 2020 and the first equipment was delivered in the summer of 2022. To date, Weeefiner has already implemented more than 50 metal and/or nutrient recovery development projects for its customers operating in various fields.