Dry and wet routes in the ceramic tile manufacturing process refer to two different technologies on how to prepare the raw materials for the forming stage. As a result of both routes a granulated solid ready to be used in the pressing stage is obtained, but the characteristics of these granulates are strongly influenced by preparation route. Historically, the dry route was firstly developed, however when the quality standards and the size of the tiles increased, the wet route was successfully introduced into the manufacturing process, and from 1990 decade it is the most widespread technology to prepare the body raw materials in the world. The powder obtained with the wet route, which has finer particle sizes and higher flowability, allowed the companies to readily produce higher quality ceramic tiles and higher sizes, but its processing is more demanding in terms of energy and water consumption and, consequently, entailing higher economic and environmental costs. Nevertheless, the new development in dry milling and granulation systems, the growing awareness on environmental impacts and European Union energy policy, and the successful use of the dry route in some important producer countries (especially Brazil), are hurrying up a reconsideration of the production process in the world. In this new scenario, the implementation of the dry route has been seen as an interesting alternative to produce ceramic tiles with lower environmental burdens and, as a consequence of that, a significant number of works have been reported in the last years on this technology, both by applied research centres and machinery producers. In this communication, a technical and environmental comparison between the dry and wet route is presented based on the most recent advancements, in order to provide information about this controversial issue in the ceramic tile world: the use of the dry route to produce high quality ceramic tiles.

1. How to reduce energy and water consumption in
the preparation of raw materials in the ceramic tile
manufacturing
Dry versus wet route
Daniel Gabaldón-Estevan | Sitges 03/11/2015
Department of Sociology and Social Anthropology, Faculty of Social Sciences,
University of Valencia- Valencia (ES) - daniel.gabaldon@uv.es
“Sustainable Futures in Practice”
ESTIBMEIC Project - GV/2014/049
A. Mezquita, S. Ferrer, E. Monfort, D. Gabaldón-Estevan

2. Environmental issues challenging the development of the ceramic tile industry
[Gabaldón-Estevan, D.; Criado, E.; Monfort, E. (2014) The Green Factor in European Manufacturing: A case study of
the Spanish ceramic tile industry. Journal of Cleaner Production 70, 242-250 ]
01

3. Europe 2020’s focus on Climate Change and Energy
Sustainability establishes three specific targets for 2020:
A.A reduction of greenhouse emissions (reference year
1990) by at least 20%
B.Obtaining 20% of the energy from renewable sources
C.Increase by 20% the energy efficiency
Motivation: 202002

4. Motivation: 205003

5. Motivation: 205004
Electrification of kilns = not currently
economically viable
Carbon Capture and Storage = unlikely to
be economically viable until well-
established
Among the so-called widespread
technologies to implement at ceramic
industrial facilities:
o changes on the raw materials
formulation for more efficient firing,
o energy management
o process optimization.

6. Raw materials
Milling
Spray drying
Glaze
preparation
Pressing Drying Glazing Firing
Floor tile
Wall tile
Raw materials
Milling
Spray drying
Glaze
preparation
Pressing Drying Glazing Firing
Floor tile
Wall tile
greenhouse emissions
renewable sources
energy efficiency
Focus:05
 greenhouse emissions
 energy efficiency
o renewable sources

7. Greenhouse emissions [Monfort, E.; Mezquita, A.; Vaquer, E.; Gabaldón-Estevan, D. (2014) La evolución
energética del sector español de baldosas cerámicas Bol. Soc. Esp. Ceram. V. 53 (3) 111-120]
06
CO2 emissions (kg CO2/t fired product) (2008)

8. Firing;
15,23;
(55%)
Drying;
2,4;
(9%)
Spray drying;
9,8;
(36%)
8
Thermal specific consumption (KWh/m2) by sub process (2007)
Greenhouse emissions [Monfort, E.; Mezquita, A.; Vaquer, E.; Gabaldón-Estevan, D. (2014) La evolución
energética del sector español de baldosas cerámicas Bol. Soc. Esp. Ceram. V. 53 (3) 111-120]
07

9. Energy efficiency
[Schematic illustration of the single-fired ceramic tile manufacturing process. Source ITC]
08
Raw materials
Milling
Spray drying
Glaze
preparation
Pressing Drying Glazing Firing
Floor tile
Wall tile
Raw materials
Milling
Spray drying
Glaze
preparation
Pressing Drying Glazing Firing
Floor tile
Wall tile
Wet or
Dry
route?
Main production stages in ceramic tile manufacture

10. Raw materials preparation by wet route
[Schematic illustration of the wet route raw materials preparation. Source ITC]
09
Proportioning of
raw materials
Milling
Storage tanks
Spray drying
Spray-dried powder
Proportioning of
raw materials
Milling
Storage tanks
Spray drying
Spray-dried powder

11. Parameters Wet process
Water consumption 0,44-0,51 m3/t d.s.
Electrical energy
consumption
38-40 kWh/t d.s.
Thermal energy
consumption
500-550 kWh/t d.s.
CO2 emissions 85-90 kg CO2 /t d.s.
Water and energy consumptions, and CO2 emissions in the wet method10

12. 12
Raw materials preparation by dry route
[Schematic illustration of the dry route raw materials preparation. Source ITC]
11
Pendulum
mill
Mixing granulator
Screen
Extra-granulate
Dryer
Silos
Standarization
Granutate
for the press
Pendulum
mill
Mixing granulator
Screen
Extra-granulate
Dryer
Silos
Standarization
Granutate
for the press

13. Water and energy consumptions, and CO2 emissions in the dry method12
Parameters Dry process
Water consumption 0,12-0,16 m3/t d.s.
Electrical energy
consumption
32-38 kWh/t d.s.
Thermal energy
consumption
111-117 kWh/t d.s.
CO2 emissions 29-35 kg CO2 /t d.s.

14. Comparison between dry and wet method13
Parameters Wet Dry Savings
Water
consumption
0,44-0,51
m3/t d.s.
0,12-0,16
m3/t d.s. (*)
71%
Electrical
energy
consumption
38-40
kWh/t d.s.
32-38
kWh/t d.s. (*)
11%
Thermal
energy
consumption
500-550
kWh/t d.s.
111-117
kWh/t d.s.
78%
CO2
emissions
85-90
kg CO2 /t d.s.
29-35
kg CO2 /t d.s.
63%
(*) Provisional data obtained in pilot plant tests

15. Conclusions I14
From the point of view of sustainability, it seems clear that the dry route to
prepare raw materials is more appropriate, but the most used is the wet
method because of the properties of the final granulate obtained.
However nowadays the technology for the dry preparation of raw materials
(pendulum mills and granulators) has improved substantially, and the
properties of the granulates obtained are similar to the ones obtained from the
spray dryer, allowing the manufacture of nearly all types of tiles.
A further advantage of the wet method being that the waste water of the
manufacturing process can be recycled in the preparation of the slurry,
reducing the fresh water consumption, and the environmental impact of the
overall process.
It should also be pointed out that the wet method allows the implementation of
cogeneration systems, facilitating the companies the generation of their own
electricity and reducing their dependence on the electricity grid, although this
is very dependent on legislation on cogeneration.

16. Conclusions II15
This study reflects the complexity of the process of transferring the latest
developments to productive sector and how those factors will affect the rate of
adoption of new or improved technologies.
As we have already shown, not always the most energetically efficient process
is the one more spread even within the EU due to the existence and interlink
of other factors such technology development, product quality, or already
existing infrastructures (atomizers).
“Innovation is often the case, in fact, of looking to
apply old solutions to new problems and applying
new solutions to old problems”
[A Reed – 2001; 126]
Last but not least, environmental and
energy policy are an essential element
when establishing paths towards cleaner
production.

17. Our references16
Gabaldón-Estevan, D.; Mezquita, A.; Ferrer, S.: Monfort, E. (2014) Is European Union Environmental Policy Efficient at
Promoting a Post-carbon Industry? The Case of Energy in the European Ceramic Tile Sector. Proceedings of the 11th ICIM
2014, Vaasa (Finland) 104-113 http://icim.vamk.fi/2014/uploads/UploadPaperDir/11thICIM2014.pdf
Mezquita, A.; Monfort, E.;Vaquer, E.; Ferrer, S.; Pitarch, J.M.; Arnal, M.A.; Cobo, F. (2014) Reduction of CO2-emissions in
ceramic tiles manufacture by combining energy-saving measures. Cfi Ber. DKG 85, 91 (5) pp. E37-E42.
Monfort, E.; Mezquita, A.; Vaquer, E.; Gabaldón-Estevan, D. (2014) La evolución energética del sector español de baldosas
cerámicas Bol. Soc. Esp. Ceram. V. 53 (3) 111-120
http://boletines.secv.es/upload/2014070792201.201453111.pdf
Gabaldón-Estevan, D.; Criado, E.; Monfort, E. (2014) The Green Factor in European Manufacturing: A case study of the
Spanish ceramic tile industry. Journal of Cleaner Production 70, 242-250
http://www.sciencedirect.com/science/article/pii/S0959652614001620
Gabaldón-Estevan, D.; Hekkert M.P. (2013) How Does the Innovation System in the Spanish Tile Sector Function? Bol. Soc.
Esp. Ceram. V. 52 (3) 151-158 http://boletines.secv.es/upload/20130704104006.201352151.pdf
Gabaldón-Estevan, D.; Fernández de Lucio, I. and Molina Morales, FX. (2012) Distritual Innovation Systems. ARBOR-Ciencia
pensamiento y cultura, 188 (753), pp. 63-73 http://arbor.revistas.csic.es/index.php/arbor/article/download/1448/1457
Gabaldón-Estevan, D. (2011) El sistema distritual de innovación cerámico de Castellón. Universitat de València. Servei de
Publicacions. http://rodrigo.uv.es/bitstream/handle/10550/23431/gabaldon.pdf?sequence=1
Monfort, E.; Mezquita, A.; Granel, R.; Vaquer, E.; Escrig, A.; Miralles, A.; Zaera, V. (2010) Analysis of energy consumption and
carbon dioxide emissions in ceramic tile manufacture Bol. Soc. Esp. Ceram. V. 49 (4) pp. 303-310
http://boletines.secv.es/upload/20100901173134.201049303.pdf
Mezquita, A.; Monfort, E.; Zaera, V. (2009) Sector azulejero y comercio de emisiones: reducción de emisiones de CO2,
benchmarking europeo. Bol. Soc. Esp. Ceram. V. 48(4) pp. 211-222
http://boletines.secv.es/upload/20090904100231.200948211.pdf
Tortajada Esparza, E.; Gabaldón-Estevan, D. and Fernández de Lucio I. (2008) La evolución tecnológica del distrito cerámico
de Castellón: la contribución de la industria de fritas, colores y esmaltes. Bol. Soc. Esp. Ceram. V. 47 (2) pp. 57-80
http://boletines.secv.es/upload/20080512114901.47[2]57-80.pdf

18. Daniel Gabaldón-Estevan | Sitges 03/11/2015
Department of Sociology and Social Anthropology, Faculty of Social Sciences,
University of Valencia- Valencia (ES) - Daniel.Gabaldon@uv.es
https://uv.academia.edu/DanielGabald%C3%B3nEstevan
https://www.researchgate.net/profile/Daniel_Gabaldon-Estevan
https://www.linkedin.com/pub/daniel-gabad%C3%B3n-estevan/23/722/aaa
http://www.slideshare.net/DanielGabaldnEstevan
http://orcid.org/0000-0003-2086-5012
http://www.researcherid.com/rid/B-5195-2011
Thank you for your attention17 ESTIBMEIC Project - GV/2014/049
Socio-Technical Study on the Incorporation of
Biofuels in the Energy Mix Ceramic Industry
Project financed by: