Novel iron rich tiling ceramic from cupper flotation waste Emilia - - PowerPoint PPT Presentation

Novel iron‐rich tiling ceramic from cupper flotation waste

Emilia Karamanova, Georgi Avdeev, Stela Atanasova‐Vladimirova, Alexander Karamanov Institute of Physical Chemistry, Bulgarian Academy of Sciences, Sofia, Bulgaria https://lab.akaramanov.com 6th International Conference on Sustainable Solid Waste Management Naxos Island, Greece, 13–16 June 2018

“Aurubis” is the leading integrated copper group and the world’s largest copper recycler. “Aurubis – Bulgaria”, Pirdop (ex‐”Georgi Damianov” and ex‐ “Cumerio”) becomes a part

• f the group in 2005.

Today this plant is one of the biggest industrial units is Bulgaria. Production volume per year: copper cathodes (99.99 % Cu) ‐ 300 000 t sulfuric acid ‐ 1 300 000 t iron silicate (main residue) ‐ 700 000 t

Tiling ponds for the “iron silicate” Possible alternative:

• Raw material for clicker production
• Inert addition for “heavy” concretes
• Road gravel
• Raw material for ceramics ?

wt % Official information Our analysis SiO2 24.0‐26.0 19.5‐20.0 Al2O3 1.0‐1.5 1‐1.5 FeO 67.0‐69.0 78.5‐79.5 CaO ‐ ‐ MgO ‐ ‐ MO (CuO, BaO , ZnO) 3.0‐5.0 1.5 Na2O ‐ ‐ K2O ‐ ‐ L.O.I. 2.0‐3.0 1.0‐1.5 Chemical composition of the “iron silicate”

Separation of fayalite (2FeO.SiO2 ) from the waste

F K G

F‐35

% in the batch 35% 45% 20% SiO2 30.3 52.6 71.5

52.5

Al2O3 0.9 33.2 1.5

17.5

FeO* 67.5 0.4 0.2

19.8

CaO 0.2 7.5

3.8

MgO 3.2

1.2

MO (CuO, BaO , ZnO ) 0.8 0.3

0.5

Na2O 15.5

4.3

K2O 0.3 0.4

0.2

L.O.I. 13.3 Ceramic with 35% flotation waste from copper production and 20 % glass cullets

HSM test of F‐35

Isothermal sintering at 1160 oC of F‐35

Isothermal sintering at 1260 oC of CFK and CFK – b (MSWA alternate ceramic)

Structure surface fracture

Phase composition

“green” (non fired) final ceramic Bulk density (g/cm3) 2.35 2.29 Skeleton density (g/cm3) 3.06 2.54 Absolute density (g/cm3) 3.06 2.91 Water absorption (%) ‐ 1.2 Closed porosity (%) ‐ 12 Open porosity (%) >25 3 (by WA)/9 (by Ar)

The decreasing of absolute density “compensate” ~ 2 firing shrinkage! “green” % g/cm3 ceramic % g/cm3 kaolin 45 2.6‐2.7 glassy phase 45‐55 2.3‐2.4 faylite 35 4.3‐4.4 hematite 15‐25 5.2‐5.3 glass cullet 20 2.5‐2.6 plagioclase 10‐20 2.6‐2.7

Density and porosity

Conclusions

• Samples of new compositions of building ceramics are obtained using

high amounts of cupper flotation waste and glass culets in the batch.

• The densification process takes place at low temperature and for a

short time.

• The obtained samples are characterized by very low open porosity

and high crystallinity, which are the main preconditions for good mechanical characteristics.

• Due to intensive re‐crystallisation processes and formation of new

phases with lower densities, the sintering process leads to a negligible firing shrinkage together with acceptable bulk density .