Geopolymer Composite Materials from Mining and Agricultural Residues for Engineering Applications: Red Mud and Rice Husk Ash | Chapter 7 | Current Research on Geography, Earth Science and Environment Vol. 3

 

The transformation of raw materials into finished products generates residues and waste, whose management has become an environmental concern. With industrialisation and increasing material complexity, human activities have led to the exponential generation of waste. The more diverse and synthetic the materials involved, the more challenging it becomes to manage waste in ways that fulfil the dual objectives of protecting human health and the environment while conserving natural resources. In the Bayer process, the reaction of bauxite with sodium hydroxide to produce alumina results in the generation of red mud (RM), a highly alkaline waste that occupies land and poses environmental risks. In Guinea, rice is a staple food, and its processing produces large quantities of rice husk (RH), which also presents disposal challenges. RH contains about 20% silica, which becomes approximately 90% silica after combustion, forming rice husk ash (RHA) — a valuable material for various applications. Geopolymer technology offers a sustainable route for the valorisation of industrial residues. This study aimed to develop and analyse geopolymer composite materials using red mud and rice husk ash as alternatives to conventional construction materials. In this study, a composite geopolymer (GP) was synthesised using RM from a local alumina plant, RH from a local rice mill in Guinea, and water glass solution (WGS). For mechanical and microstructural characterisation, the geopolymer specimens were categorised into three main groups—GPA, GPB, and GPC—based on varying RM and RHA ratios while keeping the water glass solution (WGS) constant at 15%. Various mix ratios of RM, RHA, and WGS were tested. The resulting specimens were evaluated for compressive strength at different curing temperatures. Microstructural characterisation was conducted using X-ray Diffraction (XRD) and Scanning Electron Microscopy (SEM). The results revealed that the final product is predominantly composed of amorphous geopolymeric phases and that higher temperatures enhance the compressive strength of the material. The XRD of RM is characterised by the presence of sharp peaks mainly caused by hematite (Fe₂O₃), gibbsite (Al(OH)₃), akdalaite (4Al₂O₃·H₂O), lepidocrocite (FeO(OH)), and calcite (CaCO₃). There are no broad humps in the pattern; hence, amorphous phases are not present in large quantities. The greatest value of compressive strength was developed by the GPB1 specimen exhibited a strength:  36,31 MPa at ambient temperature and 66,97 MPa at 1000°C. Through geopolymerization, RM and RH are not stored in piles or dumped into nature; this is a considerable achievement for the circular economy and the zero waste principle.

 

 

Author(s) Details

D. Sidibé
Higher Institute of Mines and Geology of Boké, ISMGB, Guinea.

 

D. Keita
Higher Institute of Mines and Geology of Boké, ISMGB, Guinea.

 

A. A. Konaté
Higher Institute of Mines and Geology of Boké, ISMGB, Guinea.

 

O. B. Kaba
Higher Institute of Mines and Geology of Boké, ISMGB, Guinea.

 

M. Cissé
Higher Institute of Mines and Geology of Boké, ISMGB, Guinea.

 

S. Traoré
Polytechnic Institute, University of Conakry, UGANC, Guinea.

 

Please see the book here :- https://doi.org/10.9734/bpi/crgese/v3/6247

Red Mud-based Geopolymer and the Innovative Application | Chapter 6 | Research Advances in Environment, Geography and Earth Science Vol. 7

 

This chapter discussed the recent development of red mud-based geopolymer and its innovative application. These researches included the seepage penetration processes and the physical mechanism of red mud filtrate with heavy metal pollutants, the creation of an advanced cementitious material from solid waste red mud through alkali-thermal activation, the corrosion resistance and frost resistance of the red mud-based material, and the solidification effect on toxic heavy metals. An idea of granular thermodynamics was extended to describe the physico-mechanical characteristics of geotechnical materials like red mud-based geopolymer. This development addresses the utilization efficiency of red mud waste, the environmental pollution and controlling technology, and the purification technology of contaminated soils.

 

 

Author(s) Details

Yonghong Hao
Tianjin Key Laboratory of Water Resources and Environment, Tianjin Normal University, Tianjin 300387, China.

 

 

Please see the book here:- https://doi.org/10.9734/bpi/raeges/v7/1727

 

Optimisation Approach and Influence of Composition and Curing Parameters on Algerian Geopolymer Paste Compressive Strength Based on Metakaolin and Slag Local Materials| Chapter 8 | Current Overview on Science and Technology Research Vol. 10

 The soluble base-activated cement has existed proposed as an alternative to Portland cement and has proved good physical, machinelike, and durability features as well as low incidental impacts.This work aims to study the production of Metakaolin/Blast kiln slag (MK/S) located geopolymer. We investigated the influence of metakaolin content, the concentration in the soluble solution, the SiO2/Na2O a hard bony structure in the jaws of vertebrates ratio, the healing temperature, and the curing occasion using a brimming factorial design with two levels to comment how the variation of these limits promotes the modifications on the new and hardened properties of presented geopolymer. Then, we analysed the optimisation of the main parameter effect, the interplays, and the predicted reaction of the generated model using factorial design in mathematical software JMP Trial 16.The limits such as something that chops ratio MR (1.5 - 2), the density of solutionDS (1.3 -1.4) g/cm3, the healing temperature of kiln OT(60- 100)C° and the curing period CT (6- 48)h were considered for each consolidation of MK/S: [(50 % MK / 50%S), ( 80 % MK /20%S ) and ( 100 % MK/ 0 % S)].

Author(s) Details:

Zeghichi Leila,
Civil Engineering Department, University of Biskra, Algeria.

Mehsas boumedienne,
LMMS Laboratory, University of M'sila, Algeria.

Benghazi zied,
Mining Institute, University of Tebessa, Algeria.

Please see the link here: https://stm.bookpi.org/COSTR-V10/article/view/8907