You may have heard of urban mining in passing, or perhaps you’ve contemplated the thought of recycling your operation’s waste material for profit. But how do you go about doing this? Let’s learn more about the concept of urban mining.

What’s an Urban Mine?

An “urban mine” is comprised of the valuable material located in Waste Electrical and Electronic Equipment (WEEE), and urban mining is the process of recovering valuable metals from discarded material.
Research in 2010 estimated that roughly 6,800 tonnes of gold was recoverable from discarded electrical equipment in Japan alone. Just think of how much valuable material can be recovered from waste deposits in your own country!
Whether your operation deals with discarded waste material or generates incinerator bottom ash (IBA) through incineration, there is an opportunity for you to make a profit by installing a fine slag treatment plant.
A fine slag treatment plant can process valuable metals from your incinerator bottom ash, which can then be sold for profit. This process can be either “wet” or “dry” depending on you’re your methodology, with both processes presenting their own set of benefits. Keep reading to learn more!

What Is Incinerator Bottom Ash?

Incinerator bottom ash (IBA) is made up of particles that do not fully combust in waste-to-energy facilities. This bottom ash often contains precious and heavy metals such as ferrous, aluminum, copper, stainless steel, and zinc.
In the ~25 million tonnes of IBA produced by Europe alone, it is estimated that nearly 25% of IBA contains recoverable valuable metals. Taking advantage of this through urban mining results in new revenue streams through existing processes.
Through urban mining, we can recover roughly anywhere between 70-90% of the gold, silver and copper found in IBA. These metals can then be sold directly to metal refiners for a profit.

What Does Fine Slag Mean?

A Fine Slag Treatment Plant (FSTP) is Sepro’s proprietary system for wet processing of incinerator bottom ash (IBA). This “wet” treatment is superior to the conventional “dry” treatment of IBA by eliminating dust creation, eliminating the aging period required for dry treatment, and resulting in cleaner final ash and a smaller environmental footprint.

A fine slag treatment plant also makes it easy to integrate urban mineral recovery into existing processes by incorporating into existing IBA plants without technical modifications. Through wet treatment, IBA can be processed by a wider series of gravity recovery technologies.

For example, iron concentrate can be recovered from IBA using a magnetic separator. This concentrator can be used for smelting application. IBA that has been cleaned of magnetic particles can be processed by a shaking table or a gravity concentrator.

A shaking table can be used to divide non-ferrous metals into heavies, middlings, and light fractions. The “heavies” fraction can be immediately claimed as valuable particles and can be sold.

The “light” fractions can be further processed in a Falcon gravity concentrator for fine particle recovery. The Falcon gravity concentrator is an ideal machine for fine mineral recovery, outperforming other machines on the market when it comes to fine particle recovery.

What’s the Difference between Wet and Dry Processing?

Fine slag treatment plants (FSTP) can be added to both “dry” and “wet” existing IBA treatment plants.
Conventional “dry” technology requires the ash to be aged for 4-6 weeks to reduce moisture to roughly 10% before the metal can be separated from the bottom ash. In some cases, this ash may also need to be crushed to increase metal liberation before it is fed into eddie current (EC) separators for metal recovery.
Due to the reliance on eddie current separators, fine metals can often be lost in a dry treatment process as most remains unliberated. This is where wet processing can be more effective.
Wet process solutions lead to higher resource recovery, lower footprint, minimized dust emissions and the ability to produce quality construction aggregates. There is no 4–6-week aging period required in the recovery of metals from IBA through a wet process, and better liberation allows for higher metal recovery rates. Wet separation is often used over dry or air separation due to less equipment wear and easier separation

Turn A Profit on Your Discarded Material

The implementation of an urban mining system can greatly reduce ash disposal costs on top of recovering valuable metals from IBA.
Sepro’s Fine Slag Treatment Plant features a pre-assembled compact and modular plant design built to European or North American standards. It features full automation as well as the following:

  • Possible adaptation to dry or wet IBA treatment plants
  • Fresh IBA and aged IBA can be treated by wet process
  • Low-intensity magnetic separator separates ferrous material
  • Available in 1 t/h to 20 t/h fines capacity per module
  • 0 – 3 mm feed particle size

If your operation deals with IBA or electronic waste, contact Sepro to see if you can churn additional profit from your existing operation.