Guidelines for Marble Granite Slurry Utilization: A Sustainable Approach

Introduction

Marble and granite industries generate millions of tonnes of slurry annually, and unregulated dumping often leads to water, soil, and air pollution. To address these concerns, the Central Pollution Control Board (CPCB) has issued detailed guidelines for marble granite slurry utilization. These guidelines aim to prevent indiscriminate disposal while promoting sustainable applications in cement, roads, construction, and other industries. With this structured approach, slurry turns from a waste liability into a valuable raw material.

Background of the Guidelines

The guidelines originate from directions by the National Green Tribunal (NGT) after cases of slurry dumping in Andhra Pradesh. CPCB consulted state boards, research institutions, and industry associations before finalizing the framework. Rajasthan, Tamil Nadu, Telangana, Gujarat, and Andhra Pradesh emerged as major slurry-generating states.

Characteristics of Slurry

Marble Slurry: Rich in calcite and dolomite, particle size 45–300 µm.
Granite Slurry: High silica and feldspar content, particle size 50–250 µm.
Both types hold 30–45% water during generation, making safe handling and drying essential.

Current Challenges in Handling

Temporary storage within unit premises.
Disposal in low-lying areas or unauthorized sites.
Limited utilization by cement and ceramic industries.
Environmental issues like dust emissions, soil contamination, and water pollution.

Key Guidelines for Storage and Management

Units must create lined storage areas to prevent seepage.
Maintain logbooks for slurry generation, storage, transport, and end-use.
Use GPS-equipped vehicles for slurry transport to avoid illegal dumping.
Local authorities and SPCBs must ensure no direct dumping into land or water.

Utilization Pathways for Marble Slurry

Cement Manufacturing – Replacement of limestone up to 15%.
Road Construction – 20–35% slurry mixed with soil for subgrade.
Geo-polymeric Concrete – Low-carbon applications using fly ash and slurry.
Hybrid Composite Wood – Panels, furniture, and cladding from waste slurry.
Low-Cost Binders – Use in plasters and non-load bearing structures.
Tiles, Blocks, and Building Materials – Bricks, pavers, and ceramics.
Filler Material – In mineral grinding industries.
Lime Manufacturing – Substitute for limestone in lime production.
Other Uses – Wall putty, poultry feed, artifacts, fertilizers, and as a flux.

Utilization Pathways for Granite Slurry

Geo-polymeric Concrete – Precast paving blocks and curbstones.
Hybrid Composite Wood – For construction and furniture industries.
Other Applications – Tiles, fillers, and aggregate replacements in concrete.

Database Management and Monitoring

SPCBs must develop online portals to track slurry generation, transport, and utilization.
End-users and processing units must be mapped and monitored.
Monthly production data and quality testing reports should be uploaded.

Regulatory Mechanism

All units must obtain CTE/CTO under Water and Air Acts.
Slurry utilization plans are now mandatory for CTO approval.
SPCBs must enforce compliance and coordinate with associations for effective utilization.
Units may seek technical support from CSIR institutes, NCB, and CPCB.

Conclusion

The CPCB guidelines on marble granite slurry utilization mark a decisive step towards sustainable waste management. With strong monitoring, industry partnerships, and innovative reuse pathways, slurry can transform from an environmental hazard into a resource for construction, cement, and allied industries. Adopting these guidelines ensures cleaner surroundings, resource efficiency, and circular economy growth.

Download: Marble Granite Slurry Utilization Guidelines for Sustainable Growth