1. HISER – WP3 ST 3.1.2: Development of novel fragmentation techniques for the selective release of materials adhered and embedded in both sorted concrete and ceramics 3 rd General Assembly meeting (18-19/02/16)

2. Electrical fragmentation Developed and commercialized by SELFRAG Use of highly energetic electrical pulses (150 - 750 J/pulse) with a very fast voltage ramp-up time (<500 ns) Fragmentation based on the discontinuities of the electrical and acoustic properties to allow liberation along natural boundaries: – Imbalance of electric charges at grains boundaries – Creation of a discharge (plasma) locally, accompanied by thermal expansion – Generation of a radial shock wave Initially developed for ore treatment Wet process but low energy intensive and with high selectivity (short duration of the treatment) > 2

3. Objectives & Samples Objectives: To study the application of the electrofragmentation technique for: – the elimination of non-desired materials contained in the stony fraction (grey, red or mixed) – the separation of the cement-sand structures from the surface of natural aggregates in concrete waste 5 types of sample have been selected for 3.1.2: – Concrete – Concrete + Gypsum – Fiber reinforced concrete – Brick + Mortar – Brick + Mortar + Gypsum

4. Test campaign at the SELFRAG facility on the continuous equipment: – Max flowrate: 800 kg/h – Particle size < 40 mm (but can be < 100-150 mm if the amount of sample is about 100 kg) Works performed since the last GA meeting

5. Brick + Mortar from a Belgian demolition site (VITO) Brick + Mortar + Gypsum from a Belgian demolition site (VITO) Concrete blocks designed for construction (BRGM) Available samples for the tests: Works performed since the last GA meeting Pre-treatment used to reduce the particle size: – For concrete: jaw crusher – For bricks: manual hammer Several operating procedures were tested, especially for the concrete sample

6. Brick + Mortar – preliminary continuous tests Sample mass: 23.8 kg Particle size > 10 mm Treatment in one single pass Manual sorting on all fractions to quantify the liberation of each component Before treatmentAfter treatment Brick + Mortar

7. Brick + Mortar – preliminary continuous tests Water content after electrofragmentation (after sieving) Particle size distribution after treatment But Energy consumption: 11.5 kWh/t and about 1 kWh/t in batch tests => room for improvement  Preliminary tests: – Need to optimize the reduction ratio – Possibility to decrease the water content by improving the sieving stage such as with a dewatering screen

8. Brick + Mortar – preliminary continuous tests 2-5 mm5-8 mm8-11.2 mm % Unbound bricks % Unbound mortar % Middlings % Unbound bricks % Unbound mortar % Middlings % Unbound bricks % Unbound mortar % Middlings 63.532.83.669.227.03.869.427.23.3 Liberation of the brick in different particle size ranges between 2 and 20 mm (middlings = brick with adhered mortar) 11.2 -16 mm16-20 mm % Unbound bricks % Unbound mortar % Middlings % Unbound bricks % Unbound mortar % Middlings 62.335.72.073.818.87.4  Very low % of middlings in the fraction 5 - 20 mm (even in the fraction 2 – 20 mm) Mortar Brick Middlings Ex: Fraction 5 – 8 mm

9. Brick + Mortar – preliminary continuous tests For the fraction 5 - 20 mm % Unbound bricks% Unbound mortar% Middlings 68.028.33.7  Very good liberation of the brick after electrofragmentation But further tests are needed to confirm the potential of the electrofragmentation: -Tests with another sample “Brick + Mortar”  Robustness of the process -This material is very brittle => Need to perform test with a conventional crushing process Samples ready for TUDelft works

10. Brick + Gypsum – preliminary continuous tests Sample mass: 10.4 kg Particle size > 20 mm Treatment in one single pass Manual sorting on all fractions to quantify the liberation of each component Before treatmentAfter treatment

11. Brick + Gypsum – preliminary continuous tests Thin and long shape of the sample => by-pass of some blocks in the current settings? Particle size distribution after treatment  Need to optimize the reduction ratio But Energy consumption: 4.8 kWh/t and about 1 kWh/t in batch tests => room for improvement

12. Brick + Gypsum – preliminary continuous tests Liberation of the components in different particle size ranges between 2 and 20 mm 2-5 mm5-8 mm8-12.5 mm % Unbound bricks % Gypsum% Middlings % Unbound bricks % Gypsum% Middlings % Unbound bricks % Gypsum% Middlings 62.430.94.770.821.67.674.910.015.0 12.5 -16 mm16-20 mm % Unbound bricks % Gypsum% Middlings % Unbound bricks % Gypsum% Middlings 63.03.431.653.22.344.5

13. Brick + Gypsum – preliminary continuous tests % Unbound bricks% Gypsum% Middlings 64.87.826.7 For the fraction 5 - 20 mm  Good liberation of components in fractions < 8-12.5 mm Samples ready for TUDelft works

14. Concrete – preliminary continuous test Sample mass: 39 kg Particle size: 2 – 40 mm Energy consumption: 3.3 kWh/t Treatment in one single pass Manual sorting on all fractions to quantify the liberation of each component Before treatment

15. Concrete – preliminary continuous test Test of another configuration for concrete treatment: – Treatment in several passes with: Recycling of middlings Addition of concrete (not already treated) to maintain input mass at a constant level

16. Concrete – preliminary continuous test Water content after electrofragmentation (after sieving) Rq: Should be possible to decrease the water content by improving the sieving stage such as with a dewatering screen

17. Concrete – preliminary continuous test Analysis of these tests are ongoing First results show a good potential to recover natural aggregates More works are needed to a complete analysis of the results such as characterization of the input concrete waste Unbound aggregates in the fraction 8 – 12.5mm

18. Planned works for the next months Further tests are planned with the continuous equipment: – Brick + Mortar: Optimization of the reduction ratio  energy consumption Test with another sample to check the robustness of the process Test with a conventional crushing process to confirm the potential of the electrofragmentation – Brick + Gypsum: Optimization of the reduction ratio  energy consumption Optimization of the equipment configuration to avoid the blocks to be by-passed – Concrete: Characterization of the input sample Optimization of the operating conditions and the settings of the continuous equipment Works will also be performed on the sample “Concrete + Gypsum” and “Fiber reinforced concrete” when samples will be ready