An apparatus (NeGaPur) is designed to study the neutralize bauxite residues (BRs) through reactive gas purging. The device comprises a specimen cell positioned on a base plate, with a plunger that can be inserted into the cell. The setup includes electrodes to measure electrical impedance, which helps in determining the extent and time of neutralization. The jacket partially encloses the cell and plunger, allowing for controlled gas purging and real-time monitoring. The setup is useful for simulating the geomaterial contaminant interaction studies in the laboratory environment. This technology offers a sustainable and efficient method to address the environmental challenges posed by bauxite residues.
Figure (1) NeGaPur- setup fabricated for the laboratory simulation study
The disposal of industrial by-products, particularly bauxite residues (BRs) from alumina refineries, poses a significant environmental challenge due to their highly alkaline nature. Traditional neutralization techniques, such as using acids, synthetic solutions, or seawater, are costly and often impractical for large-scale, in-situ applications. These methods also present difficulties in handling and potential adverse effects on the environment. With alumina refineries shifting from slurry to semi-dry BRs disposal, an effective, sustainable, and efficient method for neutralizing these residues is urgently needed to mitigate their long-lasting impact on land, water, and air pollution.
- Sustainable and Cost-effective: Provides a non-chemical, sustainable alternative to traditional neutralization methods.
- Impedance Measurement: Real-time monitoring of the neutralization process through electrical impedance provides precise and immediate feedback, allowing for better control and optimization.
- Reactive Gas Utilization: Unlike traditional methods that rely on liquid neutralizers, this method uses gases like CO2 and SO3, which can be more easily controlled and distributed.
A standalone apparatus named NeGaPur has been developed to simulate the neutralization of semi-dry bauxite residues (BRs) by gas purging under real-field conditions. The device includes a stainless-steel plunger and acrylic specimen cell housed within a gas-tight assembly. BRs are packed in 3 layers inside the specimen cell, and point electrodes are inserted through its walls to measure electrical impedance during gas interaction. Carbon dioxide (CO₂) is purged through the specimen using dedicated inlet ports, and the impedance changes are recorded over time using an impedance analyzer (3 µHz to 40 MHz, 1.414 V RMS) to monitor the neutralization process. A drop in DC conductivity over 0–12 days confirms successful carbonation. Post-treatment, the specimen is analyzed for pH, electrical conductivity, and thermal behavior to confirm the formation of neutralization byproducts such as Na₂CO₃ and CaCO₃.
The lab-scale studies and pilot scale demonstration have been performed.
6
This technology offers a sustainable solution to neutralize large quantities of highly alkaline bauxite residues, reducing their environmental impact. It can help improve land quality, prevent groundwater contamination, and reduce air pollution.
- Alumina Refinery Waste Management: Neutralization of bauxite residues to prevent environmental contamination.
- Environmental Remediation Projects: Use in projects aimed at mitigating the impact of industrial by-products on the environment.
- Process Control and Optimization in Waste Treatment: Enhancing efficiency and effectiveness of industrial waste treatment through real-time monitoring.
Geography of IP
Type of IP
202021023816
433714