SECONDARY AGGREGATES FROM IBA: PROJECTS

As early as 2017 and 2018, the French REMEX subsidiary REMEX RESSOURCES MINÉRALES SAS had already supplied a total of 30,000 tonnes of incinerator bottom ash (IBA) and a further 25,000 tonnes of excavated soil for the construction of the Rocade Sud. The secondary materials were used for the road substructure and for the construction of ramps.

The project belongs to a set of measures to improve the especially critical traffic situation in the city of Strasbourg. Among the measures are two large road construction projects that are currently being implemented in the surrounding area of Strasbourg:

• The southern bypass (Rocade Sud), construction period 2015 to 2020
• The western bypass (Grand Contournement Ouest), construction period 2018 to 2020

The IBA used in Strasbourg stems from the new REMEX IBA processing plant in Mannheim, Germany. The main volumes of delivered soil originated also from Germany, i.e. from various construction sites located in the neighbouring federal state Baden-Wuerttemberg.

The respective contracting parties were a consortia led by VINCI and Eurovia. REMEX’ services included the sourcing and provision of suitable secondary aggregates, quality control, the organisation of cross-border waste shipments (notifications) and logistics with trusted regional partners.

Based on successful implementation during the first construction phases, REMEX expects to continue the cooperation with VINCI and Eurovia at the same scale.

REMEX’s most recently built processing plant is located in Mannheim, Germany. The two-hectare site, which until last year accommodated a mobile plant, now features an impressive stationary plant with an annual capacity of approx. 200,000 tonnes of incinerator bottom ash (IBA).

The dismantling of the old installation began in April 2018, and individual elements such as non-ferrous separators and overband magnets were reused in the new facility. Construction work began in May and trial operation began at the end of August 2018. Since 31 October, the recycling plant is being officially operated with a throughput of up to 1,000 tonnes per day.

The new Mannheim plant boasts a double-deck screen and two flip-flow screens, four magnetic separators and four eddy current separators. The processing takes place at screen fractions of the grain sizes 2/4, 4/8, 8/16, 16/50 and 50/200 mm. As in all REMEX plants, there is also a manual sorting station in which employees extract valuable metals from the larger grain sizes as well as a wind sifter that removes organic materials such as paper or wood. In addition, > MERIT^® technology is used, which is a REMEX developed technology that increases the recovery of fine non-ferrous metals.

Michael Stoll, Managing Director of REMEX Mineralstoff GmbH: "With the newly commissioned plant in Baden-Wuerttemberg, REMEX demonstrates once more its expertise on increasing both the recovery of metals and the quality of the mineral fraction of IBA incinerator bottom ash. In addition, the implemented screening techniques and the plant design allow us to produce different mineral fractions, which means that we are extremely flexible to meet customer requirements for secondary aggregates.”

With its judgment of 27 December 2018, the Dutch court "Raad van State“ made an important decision on the shipment of hazardous waste, in this case fly ash from flue gas cleaning facilities, as stowage material in salt mines.

As part of a notification for the shipment of hazardous waste from the Netherlands to Germany, the responsible Dutch authority, in the summer of 2017, initially refused to grant full consent to the notification. The use of hazardous waste as stowage material would be a disposal operation and therefore primarily to be carried out in the Netherlands, according to the reasons given by the authority at the time.

The Dutch authority based its opinion largely on the new definition of backfilling, which was introduced in the Waste Framework Directive in 2018. Backfilling is a recovery operation under the Waste Framework Directive and limited to non-hazardous waste. The authority interpreted the definition as meaning that backfilling would include underground stowage and that accordingly, only the use of non-hazardous waste was deemed recovery. Since the fly ash from flue gas cleaning is hazardous waste, the authority concluded in this case that by implication stowage counted as disposal.

The court did not follow this view in its proceedings. In the court’s view, the authority’s reasoning that stowage is backfill within the meaning of the new Waste Framework Directive is incorrect. According to the court, the concept of backfilling covers only above-ground backfilling, for example of clay or gravel pits, but not the use of waste underground. Consequently, the backfilling of excavated areas must be distinguished from underground stowage.

The judgment thus confirms the existing position of German authorities that the use of waste, in particular fly ash or flue gas, as material for underground stabilisation of mines is a recovery operation because it replaces natural construction materials. This means that waste from abroad can continue to be used as raw material for stowage.

> Read the ruling
> Waste Framework Directive
> aurec.de (German website)