Comparative LCA of Flooring materials: Ceramic vs. Marble Tiles

Mari Nissinen

Background

• Italy is the most important producer of ceramic and marble tiles for buildings

• Italy covers 23% of the world output of ceramic tiles

• 18% of the world output of marble tiles

• Growing interest in environmental concerns in the building sector

The Goal and Scope (1/2)

• To compare environmental profiles of the ceramic and marble tile which one has the best environmental profile? What are the hot-spots of the systems?

• Single-fired ceramic vs. marble tile

• Functional unit: 1m2 and period: 40 years

• Few operations have been excluded

The Goal and Scope (2/2)

• No allocation procedure was done• Impact assessment methodology is problem-

oriented• Impact categories: abiotic resources, global

warming,ozone layer depletion, human toxicity, aquatic toxicity, acidification, nutrification and photochemical oxidant creation

• Normalisation factors by Directoraat-Generaal Rijkswaterstaat

• Weighting factors by NOGEPA

Assumptions

• Emissions of the electric energy production are relative to the Italian energy system

• The distance of the transport of the packaging materials is 10km from the collection point to the municipal solid waste incinerator

• The distance of the tilling demolition to the landfill is 20km

Ceramic Tile

• Average weight: 18kg/m2

• Manufacturing in North Italy• The main countries from which raw material are

imported, are identified using the Italian Trade Statistics

• Flue gas amounts are averages of different plants

• Manufacturing waste is recycled into the system• Average life of the tiles: 20 years

Marble Tile

• Average weight 48,6kg/m2, thickness 1,8cm• Manufactured in the centre of Italy• Manufacturing waste is recycled out of the

system after the required treatments• Distance from the sedimentation tank to the

landfill for sludge is 10km• Filter-press solid waste (marmettola)

disposal in landfill, distance 10km• Average life 40 years

Ceramic tile inventory analysis (1/6)

• Two stages of productive cycle: 1) Body & glaze manufacturing and 2) Laying of the glaze to the body and the firing of the glazed body

• The process starts with the wet grinding of raw materials, after the forming it is dried in kilns

• 1,15-1,2t raw materials is needed to obtain 1t of finished product

Ceramic tile inventory analysis (2/6)

• Raw materials:

- Argillaceous materials (45%)

- Degreasing materials (15%)

- Soldering materials (40%: feldspars (25%) and limestone (15%))

- Recovered materials

Ceramic tile inventory analysis (3/6)

• Mix preparation consists of grinding, mixing-soaking and regulation of the water content

• The main emissions in to the atmosphere are related to the movement and grinding of raw materials (dust & burning of natural gas)

• Aim of forming is to mould the tile in the spesific ”green” format. Pressing process is used in forming

• The water content of a dried tile is <1%

Ceramic tile inventory analysis (4/6)

• Glazes can be transparent, opaque or coloured

• 1kg/m2 of glaze is required for the enamelling• Fuel for firing kilns is methane• Water required is 12 l/m2

• Packaging: cardboard boxes with polythene sheets

• No emissions during the use phase• Disposal: landfill

Ceramic tile inventory analysis (5/6)

Ceramic tile inventory analysis (6/6)

Marble tile inventory analysis (1/2)

• Productive cycle consists of- Quarry operations

- Raw blocks cutting

- Cutting of the standard size blocks

- Polishing, buffing

• Packaging: wooden boxes

• Disposal: landfill

Marble tile inventory analysis (2/2)

Impact Assessment (1/8)

• Electric and thermal energy needed to manufacture of 1m2 ceramic tile is 161,67MJ

• Marble tile 161,83MJ• Ceramic tile process requires lots of

thermal energy and marble electric energy• Most important categories in eco-

indicators are global warming, human toxicity and acidification

Impact Assessment (2/8)

Impact Assessment (3/8)

Impact Assessment (4/8)

Impact Assessment (5/8)

Impact Assessment (6/8)

Impact Assessment (7/8)

Impact Assessment (8/8)

Results

• Marble tile (1,90e-12) scores about two times better than ceramic tile (4,21e-12)

• Emissions to air for both over 90% of emissions• The highest environmental burden for marble tile

system is preproduction• For ceramic system: preparation of the body,

fusion of the frit and the firing of the glazed body• Marble tile process requires much electric

energy, ceramic process thermal energy• Improvements suggested be done: more

efficient technology for marble energy costs ↓ Ceramic: thermal energy ↓

THANK YOU!!