Waste batteries will no longer have a negative impact on the climate

A new Russian technology makes it possible to extract non-ferrous metals from them without emitting СО2 and damaging the environment.

Photo by: Duracell / Вконтакте

Scientists at Ural Federal University (UrFU) have created a technology for extracting non-ferrous metals from old zinc-manganese batteries. The recovered recyclable materials can then be used in metallurgy, the university’s press service reported.

Zinc-manganese batteries are widespread in households — they are used in clocks, wireless computer mice, remote controls, toys and many other devices.

Zinc and manganese are both valuable metals. Recycled zinc is used to refine gold from impurities while manganese is used to remove dissolved oxygen from steel and to smelt super-tough and hard alloys. In addition, manganese is not produced in metallic form in Russia.

According to scientists at the Ural Federal University, every year about 1 billion used zinc-manganese batteries are accumulated in Russia, and no more than 3% of them end up in recycling. Old batteries, when dumped in a landfill, can spontaneously combust and cause a fire. When they burn, they release dioxins into the air — toxic compounds that have mutagenic, carcinogenic and immune-suppressing effects. This has an extremely negative impact on the climate.

Recyclable materials are recovered from shredded batteries. Zinc is produced by dissolving the powder in strong alkalis and then extracting the metal from the composition using an electric current. The undissolved residue is smelted into metallic manganese.

Researchers have determined the optimum alkali concentration, temperature and ratio of solids in the liquid to extract the maximum amount of metal from the waste. The whole process takes about an hour.

“Extraction of metals from the material is complicated by the presence of heterolite and hydroheterolite in its composition. These are strong zinc and manganese oxide compounds that form during battery operation and do not dissolve in alkaline solutions.

We were extracting about 20% of the zinc from them, and the percentage can only be increased by re-leaching. So we are working to improve the technology and achieve destruction of zinc-manganese oxides to increase the recoverable percentage of non-ferrous metals,” said Dana Bludova, co-author of the publication and assistant professor of non-ferrous metals metallurgy at UrFU.

The university stressed that the new battery recycling technology will not require the construction of separate plants and can be implemented at existing metallurgical plants, which have vibrating screens, reactors with mechanical agitation, filters, electrolysis baths, induction and drying furnaces. A small line with a shredder and a magnetic separator is sufficient to open and remove the steel shells of the batteries.

Cover photo: GarryKillian / iStock