Papers by Keyword: Industrial Waste

Abstract: Geopolymer is an alkali-activated aluminosilicate material that combine ceramic-like thermal performance with low thermal conductivity, high-temperature resistance, while remaining castable and structurally adaptable. It is synthesized from calcined kaolin (metakaolin) and fly ash, which react with alkaline solutions to form strong covalent bonds through geopolymerization. This material offers a viable alternative to conventional refractories and imported ceramic products.In this study, a geopolymer material was developed for welding applications and utilized as a weld backing strip for gas metal arc welding (GMAW) of ASTM A36 carbon steel. Weld backing strips are essential for achieving full penetration and consistent root quality in large-scale steel fabrication, particularly in structural, shipbuilding, and heavy industrial construction. The geopolymer binder consisted of 35 wt% metakaolin, 15 wt% fly ash, and a 1:1 ratio of 10 M NaOH and sodium silicate solution. To enhance thermal resistance, river sand, fine glass powder, or recycled SAW flux was incorporated as an external solid phase. Geopolymer specimens were thermally cured and fired at 500 °C to eliminate moisture and organic. Moreover, it was heated to 900 °C to simulate welding heat exposure. Microstructural, mineralogical, and functional group transformations were evaluated using XRD, SEM, and FTIR, while mechanical strength, thermal conductivity, and density were also assessed. The results indicated that glass-enhanced geopolymer exhibited the lowest thermal conductivity (0.89 W/m·K) and highest compressive strength retention after firing, owing to its partial crystallinity and preserved amorphous phase. Flux-based composites showed extensive ceramic phase formation, while sand-based composites retained high thermal conductivity and suffered severe strength loss. Welding trials confirmed that geopolymer backings effectively supported root bead formation with no cracking.

Abstract: The scourge of tonnes of waste generation from municipal, industrial, and medical facilities, among other sources, is a serious concern, significantly the increase in disposal through landfills, incineration, and others, which may pose further health and environmental challenges. In our work, we intend to study the characteristics of foam glass made from hazardous waste incinerator slags (HWIS) and waste bottle glass with 1.5%wt SiC used as foaming agents. Varying percentages (10%wt, 20%wt, 25%wt) of slags were sintered with waste bottles (88.5%wt, 78.5%wt, 73.5%wt). The increase in the height of the green samples with temperature rise, properties of the produced foam glass-like thermal conductivity (0.04-0.135W/mK), effusivity, water absorption (31.93%-98.67%), and compressive strength (3.92-5.61MPa) were checked as well. Our results gave great possibilities for the applicability of slags as secondary raw materials for foam glass production with good thermal insulating characteristics and other physical properties relevant to the expectations of construction materials.

Abstract: In this work, the waste gypsum from industry is repurposed to add value in the medical field by transforming it into Plaster cast. The waste gypsum or calcium sulfate dihydrate is heated to a temperature of 120 °C for three hours to obtain calcium sulfate hemihydrate or Plaster of Paris. Subsequently, it is mixed with water in a 1:1 ratio before embedded on gauze. To enhance the strength of the plaster cast, different types of starch-based adhesives are mixed with plaster solution to investigate their impact on shaping and the strength of the plaster. Three types of starch, including potato starch, tapioca starch, and cornstarch, are utilized. After testing the strength of plaster cast mixed with adhesive starch, it is found that with 5% potato starch, the plaster cast exhibits the highest strength among all variants. In addition, its result from SEM indicated that the potato starch was distributed and packed tightly onto gauze.

Abstract: It is crucial to utilize industrial waste and recycled bricks in concrete production, particularly in lightweight concrete, for the sake of sustainability. The objective of this investigation is to produce sustainable, durable, and structural lightweight concrete by replacing natural aggregates (dolomite and sand) with industrial waste (plastic waste) and recycled bricks (crushed lightweight bricks). Two groups of mixtures were conducted in which coarse plastic waste and coarse crushed lightweight bricks were used to partially and fully replace the coarse aggregate in the first group. In the second group, besides replacing the fine aggregate with fine crushed lightweight bricks, the coarse aggregate is also partially and completely replaced, respectively. This experimental work investigated how sustainable lightweight concrete performs in terms of dry density, compressive strength, resistance to chloride penetration, sorptivity, water permeability, and ecological impact. Based on experimental data, replacing aggregate reduced the density of lightweight concrete by up to 1400 kg/m³, lowered its compressive strength by up to 33.8 MPa upon complete replacement of the aggregate, and diminished carbon emissions by up to 2.05%. Compressive strength correlates directly with dry density and inversely with sorptivity and permeability. Investigations have concluded the potential for producing eco-friendly lightweight aggregate concrete suitable for sustainable structural applications.

Abstract: Globally, manufacturing industries are generating a large volume of solid waste during their processes. These wastes, when spread through soil/water affect public health. This work focuses on the use of solid industrial waste from herbal medicine and TiO₂ manufacturing industries to produce iron oxide incorporated biochar, which can be served as adsorbent and low cost catalyst for many reactions. Biochar was produced by the slow pyrolysis of waste collected from herbal manufacturing units using tubular furnace at 550°C at a heating rate of 5°C/min. The iron oxide waste collected from Kerala Minerals and Metals Limited, Kerala, India (KMML), was incorporated into the produced biochar by using planetary ball mill apparatus. Structural and elemental analysis of produced biochar and Fe₂O₃ incorporated biochar was conducted using XRD, SEM and SEM-EDS, BET surface area analysis, ICP-OES, and CHNS analysis. The H/C ratio of prepared biochar shows it has a rectangular layered structure of 50*50 aromatic cluster size. The changes in bonds and groups before and after metal incorporation were studied using FTIR spectroscopic analysis and temperature stability of prepared samples were analyzed using TGA. The molecular structure of produced biochar and changes in their bond length was studied and optimized employing Avogadro and Chemcraft software. The BET analysis shows the surface area of biochar become increased after the metallic incorporation. The same results were concluded from the molecular modelling data obtained from Chemcraft software. These results proved that the biochar surface area and pore volume can be increased by incorporation of iron oxide from industrial waste.

Abstract: In recent years, in the field of waste management, waste-to-energy plants have been attained great attention as a valid method for mitigating landfill disposal in addition to valorizing waste from the energy point of view. Moreover, there are several technological proposals aimed at valorizing and reusing the residues produced by incinerators. Nonetheless, pre-treatment and treatment techniques, including washing and the solidification/stabilization process, may be necessary for the recovery and recycling of this type of by-product. In this regard, the objective of this research is the production of lightweight artificial aggregates with acceptable quality, capable of guaranteeing specific requirements and technical performance, through the recycling of fly ash derived from municipal solid waste incineration (MSWI). The properties of the three types of aggregates, produced through the cold-bonding pelletization, were evaluated through the mechanical and leaching tests.

Abstract: Accumulation of spent garnet the world over poses a threat to the environment as it can cause water pollution when it enters waterways during flooding or runoff. This study summarizes potential solidification of spent garnet in concrete and the use of magnesia cement to stabilize the heavy metals in the concrete. The concrete will then be able to be used for construction purposes. The research was conducted in two phases. The first phase was preparing different percentages of spent garnet mortar at 0%, 10%, 20% and 30% and cured for 28 days. The compressive strength and density of the spent garnet mortar in 100x50 mm samples was compared against those of sand mortar. 10% application obtained the highest strength of 15.97N/mm². The second phase was preparing another set of mortar mix with 10% spent garnet and 5%, 10%, 15% of magnesia cement. The mortars were cured in distilled water and the results shown that 28 Days strength for 90:10, OPC: MgO ratio was able to achieve 21.4 N/mm². This ratio also shown recommendable low leaching of heavy metals.

Abstract: Industrial waste is primarily handled using landfills in both developed and developing countries. While there has been a significant rise in solid waste reduction, reuse, and recycling, landfill disposal will inevitably remain the most commonly used form of waste management. Although landfilling provides an economic means of waste disposal, it can lead to environmental degradation by releasing various contaminants if not managed properly. In this work, industrial waste from electrostatic precipitators (ESP) will be beneficial for the production of coatings on metal substrates. The sol-gel coating method have been attempted for deposition on pure Mg samples. Using the potentiodynamic polarization (PDP) method and hydrogen evolution analysis, the effectiveness of the coating, which is the corrosion resistance was analyzed. A minimal application of Tetraethyl orthosilicate (TEOS) in the ESP dust solution has been shown to substantially reduce the corrosion rate of Mg. This is likely due to the impact of its concentrations through the sol-gel process that could increase the size of the particle shape or growth.

Abstract: The focus of this research paper is the preparation of inorganic foam glass-ceramic with the utilization of waste diatomite as a raw material. The waste diatomite was first comprehensively characterized by the analysis of the chemical and mineralogical composition, particle size, thermal analyses, and microstructure by scanning electron microscopy. Followed by the pretreatment of the mixtures with the addition of a foaming agent which was sodium hydroxide. The mixtures were then formed by pressing them into pellets and fired by a powder sintering method. The pretreatment drying temperatures and firing temperatures of the prepared mixtures were evaluated. After firing, the resulting properties of the foam glass-ceramic were investigated with the utilization of an X-ray diffraction analysis, bulk density, and compressive strength. The possibility of utilization of waste diatomite in raw material mixtures for the preparation of inorganic foam glass-ceramic was investigated.

Abstract: In this research, iron modified activated carbon (FeAC) was prepared through chemical activation method to enhance the adsorption potential of activated carbon (AC) towards the removal of Reactive Blue 19 (RB 19) dye in batik wastewater and aqueous solution. The adsorbents were characterized by various characterization techniques while the industrial wastewater and aqueous solution were characterized using UV-Vis spectroscopy and chemical oxygen demand (COD) analysis. The effects of various parameters such as adsorbent dosage, amount of H₂O₂, contact time, initial RB 19 dye concentration, pH and the reusability of the adsorbent in the presence and absence of 30 % w/w H₂O₂ were investigated. In the presence of H₂O₂, FeAC exhibited the highest removal efficiencies ( > 90.0 %) for RB 19 dye in both industrial wastewater and aqueous solution using 0.2 g adsorbent, 10 mL of 30 % w/w H₂O₂ and at ambient pH within 480 minutes compared to the AC and FeAC alone.