Used batteries are collected with red boxes found in stores all around Finland. A significant portion, about 80 percent, of all the batteries that end up in those boxes are alkaline batteries. For Tracegrow, the idea for our company’s process grew out of this specific need: what can we do with a huge amount of alkaline batteries?
The traditional method has been to crush the batteries, recover the steel and then send the remaining battery mass to a smelter. However, this is expensive, takes a lot of energy and not all of the fractions can be recycled efficiently.
Tracegrow developed an alternative approach. Plants need zinc and manganese to grow, and these are found in abundance in alkaline batteries. As the company’s main owners have an agricultural background and a wealth of interest in the subject, the company focused its research on the process of dissolving and purifying these metals from the battery waste. In addition, the collaboration with the University of Oulu and the team of Professor Ulla Lassi led to the discovery that the trace elements contained in the batteries were in a form that allowed them to be processed into raw materials needed for fertilizers.
Extracting nutrients by dissolving
Prior to entering Tracegrow’s production, our partners crush the used batteries, separate the iron from them for recycling and deliver the remaining contents of the battery, the so-called black mass, to our factory at Kärsämäki. From this powdery mass we first separate the zinc and manganese into a solution. This solution is then purified by separating harmful metals such as nickel and cadmium from the solution with our patented technology. The finished solution is a liquid micro-nutrient fertiliser that is also suitable for organic farming.
Our company has already sold our products to 14 countries such as Canada and Australia. The ZM-Grow fertiliser we have developed from used batteries has been found to be very effective in international tests for the most important crops, giving up to tens of percents in yield increases per hectare, providing additional income and crop security for farmers.
The product has also won many awards for Tracegrow, such as the Ministry of the Environment’s Circwaste Award for significant work for the promotion of circular economy, the Agricultural Machinery Trade Fair’s gold medal for New Products for its easy-to-use and functional circular economy product, and the Finnish Chemical Society’s circular economy innovation award.
Organic fertiliser from batteries, how on earth?
As ZM-Grow meets the purity requirements of the EU fertiliser legislation, it was expected that the product would be approved as an organic fertiliser. What counts in organic fertilisers is the quality and purity of the final product, not necessarily its raw material. Because of this, the approval of an ecological, purified ZM-Grow solution made from recycled materials as an organic fertiliser was achieved.
The technology we have developed is an excellent example of domestic circular economy expertise. Tracegrow has continued our research and product development to develop new products from other types of waste- and by-products. Last autumn, we launched a new fertiliser, ZMC-Grow, which has been blended with recycled copper refined from, for example, used copper cables.
In addition, we will continue on our path of innovation and the development of new products is in full swing. Our motivated staff has strong expertise in chemistry and international sales, and most importantly – the enthusiasm to solve new circular economy challenges is coded in our company’s DNA.
CEO of Tracegrow Oy