Paper Sludge Reuse in Lightweight Aggregates Manufacturing.

Area of Science:

• Materials Science
• Civil Engineering
• Environmental Engineering

Background:

• Traditional lightweight aggregates require high sintering temperatures (~1200 °C).
• High energy costs and CO2 emission regulations challenge conventional production methods.
• Developing sustainable alternatives is crucial for the civil engineering market.

Purpose of the Study:

• To develop a sintered-type lightweight aggregate using paper sludge.
• To reduce energy consumption in the lightweight aggregate production process.
• To investigate the effect of paper sludge substitution on sintering temperature and aggregate properties.

Main Methods:

• Utilized two types of paper sludge: green clay paper sludge and paper pulp sludge.
• Substituted reservoir sediment clay with varying percentages of paper sludge.
• Sintered the composite material and analyzed its properties (particle density, water absorption, loss on ignition).

Main Results:

• Optimal substitution ranges identified: 10%-50% for green clay paper sludge and 10%-40% for paper pulp sludge.
• Paper sludge substitution effectively reduced sintering temperatures.
• Resulting aggregates exhibited particle density (0.66-1.69 g/cm³), water absorption (5%-30%), and loss on ignition (10%-43%).
• Increased paper sludge content correlated with higher loss on ignition, indicating its calorific value contribution.

Conclusions:

• Paper sludge is a viable material for producing lightweight aggregates.
• Paper sludge acts as an internal heat source, reducing overall energy requirements for sintering.
• This method offers a sustainable and cost-effective approach to lightweight aggregate production.