By Kelvin Naidoo, Manufacturing and Technical Director of AutoX.
AutoX is the manufacturer of the leading automotive battery brands Willard and SABAT and the official distributor of the world renowned VARTA automotive batteries.
Lead acid batteries are one of the few battery types that embrace a fully circular economic cycle from manufacture to recycling of over 98% of the battery.
An intricate and efficient international infrastructure to close the loop from cradle to grave and back to cradle has been established over many decades, protecting the environment,people and resources.
A lead acid battery consists of lead, sulphuric acid and various plastics, all of which are recycled in this process. In South Africa, the recycling process begins with the collection of scrap used batteries. These car batteries are subject to an industry-managed scrap deposit scheme where every new battery sold has a scrap deposit added to the selling price. The deposit is returned on receipt of the scrap battery.
The scheme encourages an exchange principle and discourages disposal. As a result, collection rates of used lead acid batteries run at levels greater than 90%.
The lead, sulphuric acid and plastic components are processed for reuse with little or no waste being produced. The recycling process starts with a simple sorting process. This process is necessary as there are other types of batteries that get mixed with standard lead batteries, such as lithium batteries, which cannot be recycled in the same process and can result in an explosion and fire if mixed in with the battery breaker.
Once sorted, a battery breaker process uses a large crusher to crush the batteries. The liquid sulphuric acid battery acid flows away to be filtered and is chemically processed into sodium sulphate for use in other industries. The solids are then sorted into metals and plastics in a water-based separation process.
When the plastic is crushed, it is washed and extruded into pellets and reused for making new battery plastic. The metals go through a smelting and refining process. This begins by melting the lead in an oven and adding the relevant components to adjust the metallic composition required for the refining process. This is done under very high, carefully controlled temperature, and a molten lead alloy of the desired composition is produced. The lead is poured into moulds and cast into ingots for use in manufacturing new batteries.
The cycling process ensures that used batteries, which all contain lead and sulphuric acid, are not dumped as waste but instead reused indefinitely.
While a number of countries recycle used batteries, it is of particular importance to South Africa as we do not have natural lead sources. Recycling keeps costs down, virtually eliminates the dependence on imports and creates employment for thousands of people from scrap and waste collectors to recycling smelters and distribution networks.
However, there are some overseas manufacturers who sell their lead-acid batteries in South Africa and are not part of the recycling process, and as a result, they do not contribute financially to recycling or the incentives. These batteries enter the scrap metal market and most are recycled by local recyclers for use in the local battery industry.