Waste-to-value systems (Reject & Sludge)
Innovative technologies for sludge and reject handling, material separation and recovery, and production of renewable energy help you reduce dependency on purchased power or fossil fuels and eliminate landfilling of waste – thus improving your mill's profitability.
Reject treatment systems for paper mill waste
Converting industrial waste into valuable resources and energy
Reject and sludge can be turned into value after proper handling.
Reject system based on drum pulping
System based on conventional pulping
Typical industrial waste sources in paper mills:
- Pulper rags
- Loose pulper rejects – containing mainly plastics, metals, stones, wood particles, etc.
- Cleaner rejects containing sand
- Lightweight rejects from coarse screening
- Rejects (e.g. pins, screening rejects) from BCTMP and TMP plants
- Bark and residuals from wood handling
- Thinning wood and residual material from forestry
Benefits of reject treatment systems
- Compliance with the legal requirements for protection of the environment, e.g. landfill directives
- Reduction of disposal and transportation costs by up to 30%
- Pre-treatment of rejects for fuel generation
- 25% reduction of greenhouse gas emissions (CO2) increases to over 40% reduction
- Additional income from recycling of raw material, e.g. metals or plastics
Modern reject equipment for deinking and industrially recycled paper grades
The following major operations are used for treating the various rejects and processing them in order to obtain clean fractions:
- Coarse and fine metal separation
- Ballistic separation of heavy particles, such as stones and bricks: ANDRITZ Ballistic Separator ReBal
- Screening by particle size
- Mechanical dewatering and compacting: ANDRITZ Reject Compactor
- Cutting and shredding to set the desired particle size: ANDRITZ Granulator UG
- Sorting of unwanted materials and impurities
- Ancillary processes and unit operations such as sand separation or channel screening: ANDRITZ Sediment Separator ReSed
- Conveying, bunkering (including baling and wrapping), and dosing the rejects
- The respective reject equipment must be combined and arranged properly to achieve maximum benefit.
Sludge dewatering
Proven and effective technology for sludge dewatering applications
The ANDRITZ sludge dewatering system portfolio covers all types of dewatering machines for all fibrous and biological paper industry sludges. Different types of sludges have different dewatering potential. ANDRITZ assists in finding the most suitable solution for each and every application.
To evaluate the dewatering characteristics of these sludges, ANDRITZ can test the sludge at its pilot plant in Graz, Austria. As an alternative, a test run using the ANDRITZ mobile test unit can be arranged at your mill.
Key equipment in the ANDRITZ sludge dewatering system
- Gravity Table GT: effective pre-dewatering of sludge with low solids in the filtrate
- Thickening Drum TD: efficient and reliable sludge thickening
- Sludge Screw Press SCS: highest capacity, highest dryness
- Continuous Pressure Filter CPF: flexible dewatering of a wide range of sludges