Utilization Of Bottom Ash Research Articles

Utilization of bottom ash for degraded soil improvement for sustainable technology

Bottom ash is one of the main products from coal combustion in coal-fired power plants. It has been applied in many applications such as landfill, cement industry or raw feed for clinker, concrete, etc. Furthermore, it can be used in agriculture to improve soil quality. However, the utilization rate of bottom ash in agriculture is still very low only 0.1% of bottom ash. The properties of bottom ash can adjust the pH in soil and provide some nutrients to improve soil quality. Moreover, the soil degradation is a major problem in agricultural countries. The soil degradation is the decline in soil quality due to the improper land use, agriculture with misuse or excess use of fertilizers and so on. In Thailand, the soil degradation is a serious problem in agriculture in the northern mountainous areas. The mainly causes of soil degradation are from human activities such as overuse of pesticide, herbicide, and fertilizer, deforestation, expansion of cultivated areas. Therefore, the objective of this research is to apply the bottom ash from Mae-Moh power plant to improve soil quality of degraded soil in Nan province, Thailand and to investigate the effects of amount of bottom ash from 0-30% by weight on some parameters such as pH, electrical conductivity (EC), bulk density and soil texture. From the result, it is clear that with higher amount of bottom ash, the quality of degraded soil has been improved especially pH and soil texture. The pH can increase from 5.664 up to 7.408. Soil texture can change from clay to loam or sandy loam. The bulk density of soil decreases at all rates of bottom ash which is favorable for plant growth. This research can be applied for soil amendment and is expected to improve the yield for plant growing. Furthermore, the practical combinations of 10% and 20% of bottom ash are considered to apply in the real field to evaluate the improvement on soil properties in the future.

Bottom ash utilization: A review on engineering applications and environmental aspects

Bottom ash produced from coal-fired power plants has been utilized in engineering applications for the purpose of recycling and solving disposal issue of bottom ash. This study reviews various applications of bottom ash in engineering fields. The engineering properties exhibited by bottom ash in terms of free draining, granular, lightweight and interlocking nanostructures allow them to be used for different functions. The bottom ash used is not limited to its raw state, but can be mixed and modified for advanced applications without neglecting the impacts on the environmental. The presence of metals in bottom ash are well known and being discussed whether they are harmful to the environment. Many countries have their own threshold limit of maximum contaminants, hence TCLP result will determine the hazardous status of bottom ash. This review helps in promoting the solution and potential usage of bottom ash, since coal is one of the dominant source of energy in power generation sector.

An investigation of bottom ash as a pozzolanic material

Fly ash has been widely used as a pozzolan, but a huge quantity of bottom ash (BA) has been disposed in landfills every year. Therefore, this paper addresses the development and recommendation of using BA as a pozzolanic material. Mortar containing BA at a replacement rate of 20% by weight was used to study the pozzolanic properties. The results showed that the BA needed to have particles retained on a No. 325 (45-µm) sieve at least 25% by weight to achieve the requirements for pozzolan class C and F as specified by ASTM C618. The mortar containing BA from which the particles retained on a No. 325 sieve of 5% by weight produced better compressive strength than control mortar after 28 days. Additionally, BA from several sources had chemical properties favorable for acting as a pozzolanic material. This study’s findings demonstrated that that BA with a proper fineness could be used as a pozzolanic material according to ASTM C618. The utilization of BA is a good solution for the added value, as well as the reduction of BA in landfills.

Fluidized bed combustion bottom ash: A better and alternative geo-material resource for construction.

Though the majority of research on fly ash has proved its worth as a construction material, the utility of bottom ash is yet questionable due to its generation during the pulverized combustion process. The bottom ash produced during the fluidized bed combustion (FBC) process is attracting more attention due to the novelty of coal combustion technology. But, to establish its suitability as construction material, it is necessary to characterize it thoroughly with respect to the geotechnical as well as mineralogical points of view. For fulfilling these objectives, the present study mainly aims at characterizing the FBC bottom ash and its comparison with pulverized coal combustion (PCC) bottom ash, collected from the same origin of coal. Suitability of FBC bottom ash as a dike filter material in contrast to PCC bottom ash in replacing traditional filter material such as sand was also studied. The suitability criteria for utilization of both bottom ash and river sand as filter material on pond ash as a base material were evaluated, and both river sand and FBC bottom ash were found to be satisfactory. The study shows that FBC bottom ash is a better geo-material than PCC bottom ash, and it could be highly recommended as an alternative suitable filter material for constructing ash dikes in place of conventional sand.

Design Experiment for Leveraging Material Value Coal Ash as Material Mixture of Paving Block

The coal-fired thermal power plant is the main source of coal ash production. Coal ash collected at the bottom of the furnace (boiler) is called coal bottom ash (CBA) and fly ash remaining combustion called coal fly ash (CFA). In Indonesia, the utilization of bottom ash and fly ash generally is still limited to landfill material due to the value of the material too low. The objective of this research is to leverage the value of the utilization of bottom ash and fly ash materials as a mixer of construction industry products. Design of Experiment (DoE) was conducted on paving block product using various experimental factors such as composition of sand, cement, bottom ash, fly ash, and curing period of product. This Design of Experiment (DoE) applied orthogonal array to finding the best mixed compositions that affect the quality of the end result. After it, the proof was performed with a compressive strength test and water absorption test to meet the standard requirements. Testing compressive strength of paving block was done at 7 days, 14 days and 28 days to get the best result.

Toxicity characteristics and durability of concrete containing coal ash as substitute for cement and river sand

The main aim of this study was to investigate the toxicity characteristics and durability of concrete containing bottom ash (BA) and fly ash (FA), as partial or total replacement of fine aggregate and Ordinary Portland cement (OPC), respectively. Concrete mixtures were prepared containing 0, 20, 50, 75 and 100% of BA as a substitute for river sand and 20% of FA as a replacement for OPC. Tests carried out were Toxicity Characteristics Leaching Procedure (TCLP), sulfate and acid attack (change in compressive strength, microstructure and weight) and elevated temperature effects (loss in compressive strength and mass as well as change in pulse velocity). Results showed that submerging coal ash concrete (CAC) mixtures in 5% sulfuric acid solution resulted in less reduction of compressive strength and mass loss compare to that of the control concrete. Moreover, sulfate resistance tests on concrete mixtures indicated that there were no mass loss and no reduction in compressive strength of all the mixtures after submersion in 5% magnesium sulfate solution. CAC showed higher weight loss and greater compressive strength reduction at elevated temperatures. From TCLP results, it is concluded that none of the elements leached higher than the maximum concentration of contaminants for toxicity characteristics. It indicates that transportation, disposal and utilization of BA and FA as clean construction material’s replacement could be utilized to reduce their environmental problems, increase efficiency and reduced unit cost production of concrete.

Influence of the Main Process Parameters on the Physical and Mechanical Properties of the Bottom Ash Ceramics

Bottom ash has been presented as a major problem of disposal throughout the world, since it is produced from the process of coal combustion in thermal power plants. However, its physical and chemical properties make the bottom ash an adequate potential construction material in variety of applications.The aim of the study was to investigate the possibility of utilization of bottom ash for production of ceramics compacts and to analyse the influence of the main process parameters and their interaction on the physical and mechanical properties of the final product. Consolidation of the powders was conducted on two bottom ash samples with particle size (S) -0.250+0.125 mm and -0.500+0.250 mm, pressing pressure (P) of 100 and 150 MPa and sintering temperature (T) of 1100 and 1150 oC. The density (r) and bending strength (s) of the dense bottom ash compacts were the response function. The optimization was performed through implementation of main effect plots, Pareto charts and 3D surface method using “Statgraphics Centurion” software package. The obtained model equations of the density and bending strength dependence from the main process parameters are solid basic data for modeling the process of ceramic production.

Experimental Study on Corrosion Behaviour of Concrete Containing Bottom Ash as Partial Replacement of Fine Aggregate

Concrete is a material synonymous with strength and longevity and plays a vital role in the construction activity. Scarcity of natural sand and its fast rising cost have paved way for use of bottom ash, a residue being collected from the thermal power stations, as substitute for sand. Recent research shows that the mechanical properties of concrete containing bottom ash as a partial replacement of fine aggregate is suitable for construction. The various parameters involved are different percentage of bottom ash and grades of concrete. This present experimental study is made on chloride induced corrosion using accelerated corrosion test (ACT) and related durability properties such as water absorption & porosity, water sorptivity and rapid chloride penetration test (RCPT). Compressive strength test is performed in order to ascertain the mechanical property of bottom ash concrete. The above tests were conducted on the concrete specimens and the results were found comparable with the control concrete up to 20% replacement of bottom ash. Utilization of bottom ash in concrete becomes more significant in cost-saving and reducing the quantity of landfill, thus providing an economical and ecological way of conservation of natural resources.

Comprehensive characterization of Indian bottom ash: Assessment of its potential utilization

ABSTRACTWith increased environmental awareness, utilization of bottom ash has become an attractive alternative to disposal. The objective of the present work was to study the environmental impact of bottom ash and to explore the possibility of its potential utilization. Comprehensive characterization of four bottom ash samples collected from different thermal power plants was investigated. Particle size distribution, bulk density, settling characteristics, specific gravity, porosity, permeability, and water-holding capacity etc. were determined for all bottom ash samples. A series of leaching tests was also performed to determine the tracing metal characterization of bottom ash. It is observed that Mn, Mg, Cr, Zn, Ni, and Cu were the most abundant elements while Pb, Mo, Fe, and Co were the least abundant elements. According to the mineral characterization, it is observed that silica (SiO2) and alumina (Al2O3) are primarily present in all samples. Quartz, mullite, and hematite were identified as the mineral phases. The properties of bottom ash give useful information about the utilization of its end use.

Experimental Study on Plastic Strips and EPS Beads Reinforced Bottom Ash Based Material

This paper pertains to the results of experimental studies carried out on newly developed geomaterial prepared by blending bottom ash with expanded polystyrene (EPS) beads, strips cut from the used and waste plastic water bottle and a binder such as ordinary Portland cement. The mix ratios used in the experimental study were 0.2, 0.4, 0.6, 0.8 and 1.0 %. The plastic strips were used in two different aspect ratios 10 and 5 with different mix proportions with respect to bottom ash 1, 2 and 3 %. The cement to bottom ash (C/BA) ratio was considered as 10 %. Cylindrical specimen of dimensions 50 mm diameter and 100 mm height was used to evaluating the compressive strength of the geomaterial for curing periods of 7, 14 and 28 days. The effect of mix ratio, percentage of plastic strips and curing period on the compressive strength, stress–strain behaviour, density and initial tangent modulus of the geomaterial were studied and results are incorporated in the paper. Test results indicated that for a particular mix ratio, the compressive strength increased with increasing aspect ratio and percentages of plastic strips. For particular curing period, the compressive strength increased with decreasing mix ratio values. For all the mix ratios, maximum compressive strength of 293.3 kPa was observed for aspect ratio of 5 and 28 days of curing period when plastic strip percentage was 3 %. The relationship between compressive stress and strain was observed to be nonlinear for all the mix ratios and curing periods. The density of geomaterial reduced from 798 to 544 kg/m3 with the addition of EPS beads from 0.2 to 1.0 %. The initial tangent modulus of geomaterial increased with increasing percentages of plastic strips. The utilization of bottom ash and waste plastic bottle strips can solve its disposal problem in environmental friendly manner in the direction of sustainable development.

Characterization of bottom ash of Pliocene lignite as ceramic composites raw material by petrographic, SEM/EDS and Raman microspectroscopical methods

An investigation has been carried out into the changes occurring in the organic and mineral matter of lignite during combustion and the effect of bottom ash characteristics on making fired-ceramic composites and lightweight heat-resistant concretes. In addition to examination of physico-chemical properties using XRD, XRF, SEM/EDS and Raman microspectroscopy, detailed petrographic studies were performed, including texture and microstructure analysis of feed coal and bottom ash, with special reference to a novel approach for bottom ash reuse in the production of ceramic composites. The results of the petrographic study show correlation of the low rank coal composition with bottom ash optical texture, providing information on the active surface gasified by oxygen, as well as the origin of char particles of woody origin that participated in the combustion process. The bottom ash microstructure is directly related to the reactivity of the porous residue and the properties of the ceramic composites produced, which include density, absorbency, porosity and firing compression strength. In particular, the reduction in density indicates an increased potential of thermal insulation of fired-ceramic composites containing up to 50% bottom ash, and lightweight heat-resistant concretes containing up to 75% bottom ash. The results of the study indicate the positive contribution that can be made by using petrography as a complementary method to study the organic phases, and SEM/EDS and Raman microspectroscopy to analyse the chemical composition of the inorganic phases, when studying bottom ash utilization, and the promising potential for bottom ash to be recycled in making ceramic composites.

Overview on the Potential of Coal-Based Bottom Ash as Low-Cost Adsorbents

The accelerating demand of energy in the world has resulted in increasing numbers of installation of coal-fired power plants. With growth in coal burning power stations, huge amounts of coal bottom ash considered as hazardous materials are anticipated to be produced. At present, coal ash residues are conventionally disposed in an on-site disposal system such as land-fill and in ash pond without any commercialization purposes. The massive generation of coal bottom ash in power plants causes a variety of environmental pollutions, with regards to presence of alkaline heavy metals and their leaching problems. In addition, huge accumulation of bottom ash results in handling and storage problems, such as inadequate spaces or facilities to hold the coal burning residues. Accordingly, a review on the prospect of coal bottom ash utilization as adsorbent material is elaborated. The physical and chemical properties of the bottom ash are discussed for a good understanding of the physiochemical characteristics and sui...

Bottom Ash 혼합토의 자중압밀 특성 연구

In order to meet the new requirements for landfill materials, this study planned a study to apply mixed soil of mixing bottom ash and coastal dredged soil to the dredged ground. Coal ash generated from thermal power plant is divided into fly ash and bottom ash. In the case of fly ash, many studies have been conducted because small particles causes permeability coefficient to be small during recycling so no problem has been raised in the environmental area but the utilization of bottom ash has been limited because environmental problems have been raised during recycling due to its larger particle size and greater permeability coefficient. According to recently published studies, however, the results of the study that conducted the water analysis of leachate generated in the ground improvement section using bottom ash showed that heavy metal contamination levels were found to be within the reference value and no significant environmental problems were found so utilization of bottom ash is evaluated to increase significantly in the future. This bottom ash has the particle size of sand and only transportation costs need to be considered when providing materials because the majority has been disposed and it is judged as the most suitable material in dredging landfill in the economic aspect because most thermal power plants are located in the coast and transportation costs can be reduced by ship. Also, research on mixed soil that can maximize the effect of the construction period and construction cost savings than dredged soil is determined as needed because the demand for coastal dredging reclamation is increasing such as Saemangeum project etc. Therefore, we studied self-weight consolidation characteristics depending on sample processing and mixing method of mixed soil by carrying out interior self-weight consolidation experiments on mixed soil of mixing bottom ash and Kaolinite according to the new development needs of recent coastal reclaimed ground and these result findings are expected to be used as basic data when applying the large coastal dredged ground in the future.

To fractionate municipal solid waste incineration bottom ash: Key for utilisation?

For the past decade, the Finnish waste sector has increasingly moved from the landfilling of municipal solid waste towards waste incineration. New challenges are faced with the growing amounts of municipal solid waste incineration bottom ash, which are mainly landfilled at the moment. Since this is not a sustainable or a profitable solution, finding different utilisation applications for the municipal solid waste incineration bottom ash is crucial. This study reports a comprehensive analysis of bottom ash properties from one waste incineration plant in Finland, which was first treated with a Dutch bottom ash recovery technique called advanced dry recovery. This novel process separates non-ferrous and ferrous metals from bottom ash, generating mineral fractions of different grain sizes (0-2 mm, 2-5 mm, 5-12 mm and 12-50 mm). The main aim of the study was to assess, whether the advanced bottom ash treatment technique, producing mineral fractions of different grain sizes and therefore properties, facilitates the utilisation of municipal solid waste incineration bottom ash in Finland. The results were encouraging; the bottom ash mineral fractions have favourable behaviour against the frost action, which is especially useful in the Finnish conditions. In addition, the leaching of most hazardous substances did not restrict the utilisation of bottom ash, especially for the larger fractions (>5 mm). Overall, this study has shown that the advanced bottom ash recovering technique can be one solution to increase the utilisation of bottom ash and furthermore decrease its landfilling in Finland.

A facile synthesis of Fe3O4–charcoal composite for the sorption of a hazardous dye from aquatic environment

Herein, we synthesized Fe3O4–charcoal composite using chemical precipitation technique and utilized it for the sorption of methylene blue from aqueous solution. The synthesized composite was characterized by Infra-red spectroscopy, N2 adsorption-desorption isotherm, X-ray diffraction, selected area electron diffraction, transmission electron microscopy, and vibrating sample magnetometer. The composite depicts absorption bands conforming to Fe–O, –OH, CO, and C–O vibrations. The composite was mesoporous in nature with a surface area of 387.30 m2 g−1. The observed diffraction planes correspond to face-centered cubic Fe3O4 and disordered graphitic carbon. The spherical Fe3O4 particles (average diameter ∼13.8 nm) were uniformly distributed in the carbon matrix of the charcoal. The saturation and remanent magnetizations demonstrate its potential for magnetic separation and reuse. The composite showed dye sorption capacities of 97.49 mg g−1 and 90.85 mg g−1 in batch and fixed-bed system. Pseudo-second order kinetics and Temkin isotherm best represented the sorption data. The sorption process was endothermic, spontaneous, and administered by electrostatic, π-π dispersive interactions, film, and intraparticle diffusion. Microwave irradiations followed by methanol elution regenerated the dye-loaded composite with nearly no loss in sorption capacity. The recovery of energy and potential utilization of bottom ash enhances the prospective of Fe3O4–charcoal composite for industrial applications.

The Utilization of Bottom Ash Coal for Briquette Products by Adding Teak Leaves Charcoal, Coconut Shell Charcoal, and Rice Husk Charcoal

The limitations of the availability of energy sources especially fuel oil has become a serious threat for the society. The use of coal for energy source as the replacement of fuel oil, in one hand, is very profitable, but on the other hand, will cause problem which is the coal ash residue. This coal ash is a by-product of coal combustion. This coal ash contains bottom ash . Through this observation, the bottom ash can be processed to be charcoal if added by teak leaves, coconut shell, and rice husk. Also, this observation needs to add binder materials for further processing in order to form briquette. It can be used as alternative fuel, the utilization of bottom ash and biomass will give positive impact to the environment. This observation was conducted by using compositions such as bottom ash, teak leaves, coconut shell, and rice husk. The treatment was using comparison 100%:0% ; 80%:20% ; 60%:40% ; 50%:50% ; 40%:60% ; 20%:80% ; 0%:100%. The result that the best briquette was on the composition of 20% bottom ash : 80% coconut shell. The characteristic values from that composition were moisture content of 3.45%, ash content of 17,32%, calorific value of 7.945,72 Cal/gr, compressive strength of 2,18 kg/cm 2 , level of CO of 105 mg/m 3, and heavy metals Cu of 29,83 µg/g and Zn 32,99 µg/g. The characteristic value from each briquette composition treatment showed that the increasing usage proportion of biomass as added material for briquette was able to increase its moisture content and calorific value. Besides, it is also able to decrease its ash content and compressive strength

The Characteristics of Asphalt Concrete Binder Course (AC-BC) Mixture with Bottom Ash as Aggregate Substitute

Highways serve nearly 80-90% of the population mobility and flow of goods. Utilization of bottom ash, a waste from coal combustion, in highway construction is one of the alternatives to reduce environmental pollution and support Clean Development Mechanism Program of Kyoto Protocol. The aim of this study is to analyze the characteristics of AC-BC mixture that uses bottom ash as partial substitute of fine aggregate and comparing with a standard mixture. Laboratory tests are performed on two different types of mixtures. The tests show that optimum asphalt content for AC-BCStandard mixture is 5.20% while AC-BCBottom Ash mixture is 5.25%. Bottom ash has higher porosity along with a little break field and has round shape so that the asphalt absorption is bigger than the crushed stone. Bottom ash can be used as an alternative aggregate to increase the value of flow of the AC-BC mixture, thus converting waste to valuable material.

Strength and durability of green concrete

The waste and by–products from industries, thermal plants, and recycled materials have been used historically in cement, concrete and other constructional activities. By–products such as fly ash, bottom ash, silica fume, etc., gains its utilisation owing to their physical, chemical and engineering properties when used either by processing or directly on concrete. This paper was aimed in making concrete green and durable by utilisation of bottom ash as sand replacement material in concrete that can conserve river sand from exploitation and also prevents environmental pollution caused by bottom ash which is dumped in the form of slurry as ash ponds. Bottom ash is replaced for river sand for 30%, 60%, and 100% in concrete. The strength and durability of concrete was evaluated to find its potential application in concrete. Experimental results show that 30% bottom ash can beneficially be added to the concrete to produce 40–50 MPa without affecting the strength. The durability of bottom ash exhibited superior and better performance than reference concrete.

Feasibility Studies on Compressive Strength of Ground Coal Ash Geopolymer Mortar

Coal ash obtained from the Thermal Power plants consists of a major portion of Flyash and less amount of Bottom ash. As a major portion of the coal ash, fly ash has been recognized widely as a source material for geopolymers while the utilization of bottom ash has received very less attention owing to its coarser size.Hence to promote greater utilisation of bottom ash in construction sector, this work proposes the use of ground bottom ash in geopolymer mortar. The effect of molar ratio of SiO2 /Na2 O, Na2 SiO3 /NaOH ratio and curing mode were studied on compressive strength of coal ash geopolymer mortar. Molarity of sodium silicate solution was kept as 8M. Ambient curing and steam curing at 60oC was attempted. Test results indicate that Na2 SiO3 /NaOH of ratio 2 with SiO2 /Na2 O molar ratio 1 mortar achieved higher compressive strength under both ambient curing and steam curing.

Recent Advances in Coal Bottom Ash Use as a New Common Portland Cement Constituent

New additions to cement will help to obtain sustainable and durable construction materials. One of these new Portland cement constituents could be coal bottom ash. Currently, it is dumped as waste, provoking an environmental problem. However, shows how this material can be used as the main constituent of Portland cement when it is mixed in an optimized proportion with fly ash. Therefore, this study may also be considered as a pre-standardization work to meet, partially, an environmental demand of society.The compressive strength and durable characteristics of standardized mortars made of coal combustion bottom and fly ash are to mortars made of CEM I 42,5 N according to the European standard EN 197-1:2011, which is used as reference. The mortars made up of bottom ash, fly ash and ordinary Portland cement mixes have similar proportions to the standardized ones for CEM II/A-V, CEM II/B-V and CEM IV/A (V) cements.It was concluded that the utilization of bottom ash mixed with fly ash does not modify the compressive strength or durable characteristics of the mortars studied in this research program.