Mineral and Paper Separation for Recovery
CONAMA Resolution No. 431/2011 classifies gypsum as Class B waste (recyclable) and prohibits landfill disposal. Technical reason: gypsum in contact with organic matter generates H2S (hydrogen sulfide) — a toxic, flammable and corrosive gas.
Drywall boards: 85-92% gypsum mineral (CaSO4-2H2O) and 6-10% cellulose paper. Recycling separates these fractions: recycled gypsum goes to cement plants (setting regulator), agriculture (soil amendment) or reincorporation into new boards (up to 20-25%); cellulose paper goes to co-processing or RDF (NCV 14-17 MJ/kg).
Estimated volume in Brazil: 800,000 tons/year. [Validate]
Process
- Reception and sorting — Segregated gypsum waste (CONAMA requirement). Manual removal of metal profiles, screws, tapes, plastics.
- Primary shredding — PR4000 — Whole boards shredded into 50-200 mm fragments. Low rotation (20-40 RPM) avoids excessive dust generation. Hardox blades resist nails and screws. Capacity: up to 20 ton/h.
- Mineral disaggregation — RAPTOR — Single-shaft shredder with integrated screen disaggregates the mineral core and partially separates the cellulose paper. Output: 10-50 mm.
- Classification — Trommel Screen — 10 mm mesh separates the fractions:
| Fraction | Composition | % of mass | End Use |
|---|---|---|---|
| 0-10 mm | Gypsum mineral | 85-92% | Cement plants, agriculture, board manufacturers |
| > 10 mm | Cellulose paper | 6-10% | Co-processing, RDF |
Separation efficiency: 85-92% gypsum recovery, 80-90% paper recovery. Cross-contamination < 5%.
- Refining (optional) — Additional screen (2 mm mesh) produces fine gypsum for agricultural applications or cement plants with strict specifications.
Recycled Gypsum Markets
| Market | Required Specification | Indicative Value |
|---|---|---|
| Cement plants (setting regulator) | SO3 > 40%, moisture < 10%, organics < 5% | R$ 80-150/ton |
| Agriculture (agricultural gypsum) | CaSO4 > 70%, no heavy metals | R$ 50-100/ton |
| Board manufacturers (reincorporation) | Residual paper < 3-5%, particle size < 2 mm | R$ 60-120/ton |
| Paper for co-processing/RDF | NCV 14-17 MJ/kg, chlorine < 0.5% | R$ 80-150/ton |
Equipment
| Equipment | Function in line | Capacity |
|---|---|---|
| PR4000 | Primary board shredding | Up to 20 ton/h, 300 hp |
| RAPTOR 3000 | Mineral disaggregation + particle size | Up to 30 ton/h, 200 hp |
| Trommel Screen TR2.5/8/10 | Gypsum/paper separation (10 mm mesh) | 110 m3/h, 15 kW |
| Trommel Screen TR2.5/10/12 | Gypsum/paper separation (10 mm mesh) | 130 m3/h, 2x11 kW |
Reference Feasibility [Validate values]
| Scale | Capacity | Estimated Investment | Estimated Payback |
|---|---|---|---|
| Small | Up to 10 ton/h | R$ 600K - R$ 1.5M | 24-48 months |
| Medium | Up to 20 ton/h | R$ 1.5 - R$ 3M | 24-48 months |
