A lot is happening in the world of the circular economy.
Heros Sluiskil BV, member of the REMEX Group - part of the Remondis Group – is a major player in this sector.
Secondary raw materials derived from WtE bottom ash (Waste-to-energy bottom ash) constitute one of the company’s main products. These raw materials originate from a number of Waste-to-Energy power plants in the Netherlands and Belgium.
Heros is located on the Canal from Ghent to Terneuzen; centrally located between the big cities and ports of Rotterdam, Antwerp, London and Paris.
Every year, 700,000 tons of WtE bottom ash are given a second life using the latest technology. With cutting-edge expertise, metals are recovered in such a way that they can be used directly by steel companies and smelters. The remaining mineral fraction (granulates) is used - in some cases after washing - as a sustainable substitute for sand and gravel.
During the WtE bottom ash (ash from incinerated household waste) treatment procedure, substantial quantities of metals are recovered including both ferrous metals such as iron and stainless steel and non-ferrous metals such as copper, lead, brass and zinc. Precious metals are also recovered. This is referred to as "Urban Mining".
The mineral products from WtE bottom ash can be classified as follows:
This is the product that remains after processing the WtE bottom ash from the combustion plants.
This granulate is currently used in road construction as a secondary PMC building material. PMC stands for Packing, Managing and Checking. This means that this granulate must be covered with suitable foil in order to prevent the leaching of metals and salts into the groundwater.
The products under the umbrella of the registered brand Granova® are a further development of the KOMO-certified building material WtE granulate. They are an excellent replacement either for primary raw materials such as sand and gravel in asphalt and concrete, or as a freely applicable foundation mixture for road construction.
a. Granova® granulaat. This requires the use of sieves and magnets to further process the above-mentioned WtE granulate.
This secondary raw material is extremely suitable as a replacement for up to 50% of primary raw materials like sand and gravel in the production of non-structural concrete, such as: depot blocks, tiles, stones, curb stones and floor slabs.
Granova® granulate is also suitable as an additive to asphalt.
b. Granova® combimix. The reprocessed WtE bottom ash is also the raw material for combimix. The granulates are washed and combined to produce a stone mixture suitable for road construction. Partly due to this washing technique, this raw material is freely applicable and therefore no longer has to be Packed, Managed and Controlled like the PMC building materials.
Granova® combimix is a CE-marked product, according to NEN-EN 13242. To guarantee the quality of the product, production takes place under the strict supervision of Heros Sluiskil BV’s company verification, supplemented by inspections carried out by an independent inspection body. Subsequent to an intense validation procedure, the Ministry of Waterways and Public Works recently certified this product and included it in its statutes 'Foundation and Elevation' and 'Safe Verges'. This makes it the first certified, freely applicable secondary building material derived from WtE bottom ash.
Important users of these mineral products are the Ministry of Waterways and Public Works, Provincial Councils and project developers and contractors.
3a. Ferrous scrap
During the reprocessing of the WtE bottom ash, ferrous metals, among other things, are removed from the granulate. After this procedure, however, the granulate is still not suitable to be sold directly to end users. A unique scrap-processing installation then makes the semi-finished product as pure as possible, resulting in a number of high-quality varieties of scrap iron.
These cleaned and copper-free scrap variants are then used as a renewable raw material in the steel industry, both in the Netherlands and abroad.
100,000 tons of scrap, both from Heros’ own production and from third parties, are processed each year.
3b. Non-ferrous Concentrate
During the reprocessing of the WtE bottom ash, the highest possible percentage of non-ferrous metals are recovered. Heros Sluiskil BV can recover metal particles as small as 1 mm.
These non-ferrous concentrates are refined in-house into pure aluminium and heavy-metal fractions, by means of a new, recently acquired installation that has been developed specifically for this purpose.
Heros Sluiskil BV aims to count as one of Europe’s leading recyclers of WtE bottom ash and related residues. A new phase has begun, in which research and development have become crucially important to fulfilling the requirements set out by the Green Deal.
The Green Deal is an agreement initiated by the Dutch National Government and the Association of Waste Processors for the purpose of "Improving the sustainability of WtE Bottom Ash applicability"
This states, among other things, that in 2017 at least half of the reprocessed WtE bottom ash had to be suitable for purposes other than PMC applications.
In anticipation of this, Heros Sluiskil added new building materials under the brand name granova®, such as granova® granulates and granova® combimix – thus adding quality products to the range of sustainable raw materials for high-quality applications in the civil engineering, concrete and asphalt industries.
Heros purifies wastewater from the chemical and food industries and remediates groundwater in their biological water treatment plant, producing clean water that can be safely discharged into the Western Scheldt river. Their location on the Ghent-Terneuzen Canal and storage capacity of up to 50,000 m3 ensure substantial logistical advantages.
Logistics solution
The treatment process takes place at a single location where the wastewater is delivered by road tanker or ship. The total logistics procedure from collection to discharge - as well as the administrative handling - is completely taken care of by Heros.
Hazardous wastewater
Hazardous wastewater is pre-treated in a physico-chemical treatment process using coagulation / flocculation agents. In some cases, the water also undergoes active carbon treatment
TTS (Tank Terminal Sluiskil) focuses on the national and international wastewater market. It is located at the 45-hectare Ecopark Terneuzen, where Heros Sluiskil is also situated, and has been operational since 2017. Semi-finished liquid products and raw materials and products can also be taken into temporary storage. EcoService Europe, ATM (Moerdijk Waste Materials Terminal) and Heros Sluiskil are joint owners of the terminal, with a total tank storage capacity of some 50,000 cubic metres distributed over 13 tanks.
