Turn tile factory waste into circular raw material

Submitted through the COP31 Sustainable Transformation Awards · SKD Türkiye (WBCSD Global Network Partner)

The company is a ceramic tile manufacturer with more than 1,000 employees, operating tile plants at several locations in Türkiye.

Tile making generates four distinct waste streams: dust collected across material handling and pressing, unfired scrap from the green line, fired scrap from the kiln line, and filter cake from the wastewater treatment plant. Historically all four were a disposal problem rather than a resource.

The handling arrangements made that worse. Dust was moved in open tractor trailers, which limited capacity, exposed workers to airborne particles and generated noise and vehicle traffic around the site. Filter cake could not be used at all, because the density needed for the body recipe could not be reached.

Two external pressures made the position untenable. Ceramic production depends on secure supply of critical minerals, where availability is constrained, and tightening regulation was narrowing the disposal routes still open to the sector. The high energy intensity of tile making adds import dependence on top of both.

The response was to treat in-house waste as a raw material feedstock rather than as a waste to be disposed of compliantly. Work began at the Çan plants in 2019 with dust waste and in January 2020 with filter cake from the wastewater treatment plant. Environmental performance has been monitored continuously from 2019, and the quantitative results below were verified as of 2025.

The initiative sits inside the company's 2021-2023 Strategic Plan under the Zero Waste Projects heading and supports a corporate 2030 target of increasing the closed-loop share of production by 100 per cent. Disclosure follows the ISSB standards (IFRS S1–S2) and TCFD-aligned reporting.

Location of the initiative: Çan, Çanakkale, Türkiye, with roll-out to the Semedeli plant in Çanakkale and the Yerköy plant in Yozgat

The model is a closed loop in which each stream leaving the production process is characterised, conditioned and returned to the tile body recipe as a secondary raw material, so that the recipe is met from internal material rather than from quarried minerals.

All four streams are handled. Dust and unfired scrap re-enter body preparation directly. Fired scrap is crushed and reintroduced at a controlled ratio. Filter cake from the wastewater treatment plant, the stream previously considered impossible to recover, is conditioned and blended in once recipe characterisation established the ratios at which body properties stay inside specification.

Two enabling changes made the loop work at industrial scale. The first is an addition to the wastewater treatment plant that brings filter cake to a usable consistency, unlocking 41,000 tonnes a year of material that had previously gone to disposal. The second is the replacement of open belt conveyors with fully enclosed screw conveyors for internal dust transport, which removed the dusting and blockage bottlenecks that had capped how much recovered material the lines could absorb.

Because the recovered streams substitute directly for quarried minerals, the crushing, screening and grinding operations that normally precede body preparation, and the haulage of material from quarry to plant, are bypassed for that share of the feed. The environmental result therefore comes from operations that no longer take place, not from managing waste more efficiently after it has been created.

Recipe development also demonstrated that stockpiles accumulated in earlier years, and not only the daily arisings, can be brought into the product composition. That converts a legacy liability into a raw material reserve and is the finding with the widest application for other producers.

Figure 1: Flow diagram of the four recovered streams — dust, unfired scrap, fired scrap and filter cake — returning to body preparation in the tile production process

Figure 2: Recovery rate by waste stream at the Çan plants, 2019 to 2025

Sustainability impact

Climate

The initiative targets the emissions embedded in preparing and delivering primary raw material rather than emissions from the kilns themselves.

Two sources are addressed. Bypassing crushing, screening and grinding removes 200,410 kWh of electricity consumption a year, which is a Scope 2 saving. Cutting the movement of quarried material to the plant removes 126,584 litres of fossil fuel a year, a saving reported under Scope 3, Category 4: Upstream transportation and distribution.

Together these produce a reduction of 427 tCO2e a year, measured against the pre-2019 arrangement in which the same material was quarried, crushed, screened and hauled.

The stated forward target is 593.5 tCO2e a year, reached by raising filter cake use to 52,000 tonnes and bringing the whole dust stream into the system.

Recovery results are reported as KPI tables in periodic production and management meetings, and life cycle performance is expressed in line with international Environmental Product Declaration certification standards.

Nature

The primary nature outcome is resource conservation at the quarry rather than emission reduction at the plant. A total of 85,631 tonnes of waste is consumed on the production line each year, and an equivalent quantity of natural mineral is therefore left unextracted, allowing that line to run with no external raw material input.

Recovery rates differ by stream: 46 per cent of dust waste, 100 per cent of unfired scrap, 77 per cent of fired scrap and 79 per cent of filter cake are now inside the closed loop. Filter cake, at 41,000 tonnes a year, had previously been recovered at zero.

The stated scaling target is to raise filter cake use to 52,000 tonnes for full utilisation of that stream and to feed the entire dust stream into the system, lifting the waste share within the recipe system by 39 per cent to 117,919 tonnes.

Research is under way into waste from outside the ceramic sector. From 2026 the targeted inputs are 100,000 to 120,000 tonnes a year of natural granite cutting waste, 60,000 tonnes a year of marble scrap and 60,000 tonnes a year of glass cullet.

Social

Removing tractor haulage of dust waste took an open, dusty transport operation out of the site and its surroundings. For the neighbouring community this lowered accident risk from waste traffic, reduced noise and cut dust emissions, which is a direct public health contribution rather than an indirect one.

Inside the plant, the same change removed the occupational health risk associated with handling and moving dust in open trailers, because internal transport is now fully enclosed.

Removing the accumulation of unusable waste also simplified day-to-day operations for production teams, who no longer manage storage and disposal of streams that the process itself can absorb.

Business impact

Benefits

The reported direct saving is TRY 110,121,268 a year across raw material, energy and operating costs. That figure combines the value of material no longer purchased or quarried, the 200,410 kWh of electricity and 126,584 litres of fossil fuel no longer consumed, and the disposal costs no longer incurred.

Exposure to two external risks falls at the same time. Dependence on constrained critical mineral supply is reduced for the share of the recipe met internally, and the regulatory risk of narrowing waste disposal routes is neutralised for the streams brought into the loop.

Operations are simpler. Waste accumulation on site is largely eliminated, and the enclosed conveying system removed the blockage and dusting events that previously interrupted material handling.

Supplier relationships improved through the joint work on preparing recovered materials to the size and physical specification the process needs, and the financial result secured management support for extending the model to further plants.

Costs

The cost base is capital investment in the wastewater treatment plant addition that conditions filter cake, in the enclosed screw conveying system that replaced the open belt lines, and in the research and development work behind waste characterisation and recipe reformulation. All of this was financed from the company's own equity, without public or external funding.

Operating costs shift rather than disappear. Disposal and haulage costs fall, while laboratory characterisation, recipe control and quality assurance effort rise, because each recovered stream has to be verified before it enters the body.

The substitution ratio is bounded by recipe compliance. Fired scrap and filter cake can only enter at ratios that keep body properties inside specification, which is why recovery rates differ by stream and why they were raised in stages rather than at once.

Costs were contained by solving the physical bottleneck once rather than repeatedly: the first phase of operation produced build-up and blockage on the production lines, and moving to a fully enclosed screw arrangement resolved that permanently instead of through recurring maintenance. Standardising the practice through ISO 14001 environmental management system procedures and writing the projects into the company budget and investment plans keeps the model funded beyond its initial phase.

Impact beyond sustainability and business

Co-benefits

The finding that historic stockpiles can be characterised and brought into the product composition extends the value of the model well beyond current arisings, because it turns stored waste into an accounted raw material reserve.

The model has already been transferred within the group under company equity financing, from the site where it was developed to the Semedeli plant in Çanakkale and the Yerköy plant in Yozgat, which demonstrates transferability between sites without external support.

Because the recovered material is documented and quantified, the results feed life cycle performance reporting under Environmental Product Declaration standards, which serves customers seeking verified material data.

Potential side-effects

Tying the recipe to internal waste streams creates a dependency in the other direction: if production volume or product mix changes, the volume and character of the arisings change with it, so the substitution ratios have to be re-verified rather than assumed stable.

Quality control effort increases permanently. Recovered streams vary more than purchased minerals, so laboratory verification becomes a continuous cost rather than a project cost.

Recovery rates below 100 per cent for dust, fired scrap and filter cake are not a temporary shortfall but a reflection of the ratios the body can currently accept; raising them further requires additional recipe work rather than additional capacity, which is why the forward targets are expressed as recipe and feed goals rather than as installed tonnage.

Typical business profile

The model suits ceramic tile and heavy clay manufacturers that carry out body preparation on site and operate their own wastewater treatment, because the recoverable streams and the recipe control both sit inside the same plant boundary.

It is most relevant to producers that already run crushing, screening and grinding ahead of body preparation and that haul mineral from quarry to plant, since the savings come from removing those operations for the substituted share of the feed.

Delivery engages a research and development function capable of waste characterisation and recipe optimisation, an investment or engineering function able to design in-plant material transport, and the operating teams responsible for wastewater treatment and raw material preparation.

Approach

1. Map every waste stream by volume, character and destination: separate the arisings into dust, unfired scrap, fired scrap and treatment plant filter cake, record the annual tonnage and current disposal route of each, and identify which stream is both largest and least recovered before any investment is considered.

2. Characterise each stream in the laboratory: run composition and physical analysis on samples from each stream so that the material is described as a raw material specification rather than as a waste description, and establish which streams can substitute for which mineral inputs.

3. Reformulate the body recipes around the recovered streams: run laboratory trials to determine the ratio at which each stream can enter the body while keeping fired properties inside product specification, and treat that ratio, not the available tonnage, as the binding constraint.

4. Invest at the bottleneck rather than across the process: add the treatment plant capability that conditions filter cake to a usable density, because unlocking the single stream with zero prior recovery released 41,000 tonnes a year and delivered more than incremental gains on streams already partly recovered.

5. Enclose internal material transport before raising throughput: replace open belt conveying with fully enclosed screw conveyors, since dusting and blockage, not recipe chemistry, were what limited how much recovered material the lines could carry in the first phase of operation.

6. Raise substitution ratios in stages after commissioning: increase the share of each stream gradually as recipe compliance is confirmed at each level, rather than switching to the target ratio in a single step.

7. Test historic stockpiles as well as daily arisings: apply the same characterisation and recipe optimisation to material stored from earlier years, which converts an accumulated liability into usable feedstock and materially enlarges the addressable volume.

8. Anchor the work in strategy, management systems and routine reporting: write the projects into the strategic plan and the annual budget and investment plans, standardise the practice through ISO 14001 environmental management system procedures, and report recovery rates and cost or benefit outcomes as KPI tables in periodic production and management meetings so that progress is tracked at senior level.

Stakeholders involved

• Project leads: The initiative is governed through the company sustainability committee, whose members include the General Manager, the Assistant General Manager for Operations, marketing directors, the Assistant General Manager for Finance, and the strategy and human resources functions. Because the work was embedded in the 2021-2023 Strategic Plan under the Zero Waste Projects heading, sponsorship sits at board and senior management level rather than within a single technical department. Progress is reviewed on two tracks: periodic production meetings examine cost, benefit and waste ratio, while periodic management meetings bringing all operations together review the same results against wider strategy.

• Company functions: The research and development centre took the lead role in waste characterisation and recipe optimisation, defining through laboratory trials and analysis which streams could enter the body and at what ratio. The investment unit designed and installed the closed-loop recovery lines in the plant and carried the field decisions, including the move from belt conveying to the enclosed screw arrangement. Operating responsibility rests with the wastewater treatment teams and the raw material crushing and screening teams, working alongside process research and development staff, so that recipe decisions and plant operation are made against the same data.

• Main providers: The infrastructure change was delivered by internal units, organically and independently of external public or private institutions, and financed from company equity. Equipment suppliers were engaged specifically on preparing recovered materials to the size and physical properties the production process requires. The move to enclosed screw conveying was decided after consultation with those suppliers and a comparison of options, with the screw arrangement selected as the most suitable solution rather than specified in advance.

• Other: The local community around the Çan site is a direct beneficiary rather than a participant: the end of waste haulage and tractor traffic reduced accident risk, noise and dust emissions in the surrounding area. Feedback runs through the periodic production and management meetings, which were designed to keep the review cycle transparent and short rather than formalised into a separate committee structure.

Key parameters to consider

The initiative is past pilot stage. It has been institutionalised at the site where it began and is in the scaling phase, having been extended under company equity financing to two further plants.

Each waste stream carries its own recovery ceiling set by recipe compliance, so results should be read stream by stream rather than as a single plant-level recovery rate.

The environmental case depends on how much preparation and haulage the substituted material displaces. Producers that quarry and prepare their own mineral will see the largest effect, because crushing, screening, grinding and transport all fall away for the substituted share.

Financial continuity is secured by including the projects in the company budget and investment plans and by standardising the practice through ISO 14001 environmental management system procedures, so the model does not depend on continued project funding.

Implementation and operations tips

Measure the result as displaced quarry tonnage, not as diverted waste tonnage. The two numbers are the same physically but tell different stories, and only the first makes the resource conservation and avoided haulage visible.

Solve the material handling problem before the recipe problem. Build-up and blockage on open conveying lines was the practical limit in the first phase, and no amount of recipe work would have raised throughput while that remained unresolved.

Do not assume a stream is unrecoverable because it has always been treated as waste. Filter cake was regarded as impossible to recover because the required density could not be reached; a targeted addition to the treatment plant plus recipe characterisation brought 41,000 tonnes a year into use.

Include legacy stockpiles in the scope from the start. Proving that stored waste can enter the product composition changes the size of the opportunity and the economics of the investment.

Keep the reporting simple and frequent. KPI tables reviewed in existing production and management meetings sustained the ratio increases better than a separate reporting structure would have.