Though it is often sent to landfills, there is significant metal value in incinerator bottom ash. Incinerator bottom ash (known as IBA), refers to the material that does not fully combust and is discharged after incineration. That ash can hold a variety of valuable metals that can be recovered and captured using a fine slag treatment plant.
If you are currently sending your IBA to landfill facilities, you could be missing substantial amounts of valuable metals that can be sold to recyclers and metal refineries for a nice profit. Not only does it feel good to help out the environment by recycling metal, but it also does wonders for the financial bottom line! In this blog, we will take a look at some of the valuable metals you can find and recover from IBA and the returns you could receive from doing so.
For this article, our data will specifically refer to fine ash only (<2mm). Besides being the industry-established size for high-G separation devices, >2 mm fine ash ensures the efficiency of wet screening, pumping, and slurry suspension.
Precious Metals in Incinerator Bottom Ash
Did you know that there are over 800 waste incinerators across the world (and over 400 in Europe alone)? That means that just in the continent of Europe, there is 20-30 million tonnes per year of incinerator bottom ash being produced. Out of that incinerator bottom ash, it is estimated that about 25% of that amount is >2mm, and considered fine bottom ash.
Within that fine bottom ash, you can find plenty of valuable metals available for recovery with a fine slag treatment plant. In fact, out of 8 unique fine IBA samples tested by Sepro Labs, the metal content averaged 0.33 % copper, 10.6 g/t silver, and 0.51 g/t gold. For gold recovery, shaking tables and high-G concentrators (such as a Falcon Concentrator) were most effective at recovering gold from fine IBA. For silver and copper, slot separators and shaking tables are the best method to use for recovery. From our experience, approximately 80% of gold, 55% of silver, and 85% of copper can be recovered in less than 1% concentrate mass.
Another benefit that comes from removing valuable metals from IBA is that the remaining mineral fraction can be used for construction purposes (depending on local regulations). That means that you can avoid the expensive tipping fees that come with sending IBA to landfills.
IBA Metal Recovery With Sepro’s Fine Slag Treatment Plant
All of the metal recovery and savings provided by IBA treatment is made possible by our proprietary fine slag treatment plant. Using a wet treatment method (which is notably superior to dry processing), our fine slag treatment plant addresses the suboptimal recovery rates most IBA treatment options provide. In addition to its effective metal recovery capabilities, our plants provide other benefits such as:
- Drastically reducing/eliminating dust creation due to wet processing
- Eliminating the aging period required for dry IBA processing
- Easy integration into existing processes
- Cleaner final ash for safe use in construction materials
- Ability to be incorporated into existing IBA plants with no technical modifications
- Higher metal recovery rates thanks to better liberation capabilities
- A small environmental footprint
For more on the valuable metals that can be found in IBA, as well as our fine slag treatment plant for recovering those metals, don’t hesitate to reach out to our urban mining team!