In Sweden, utilisation of incinerator residues outside disposal areas is restricted by environmental concerns, as such residues commonly contain greater amounts of potentially toxic trace elements than the natural materials they replace. On the other hand, utilisation can also provide environmental benefits by decreasing the need for landfill and reducing raw material extraction. This thesis provides increased knowledge and proposes better approaches for environmental assessment of incinerator residue utilisation, particularly bottom ash from municipal solid waste incineration (MSWI).A life cycle assessment (LCA) based approach was outlined for environmental assessment of incinerator residue utilisation, in which leaching of trace elements as well as other emissions to air and water and the use of resources were regarded as constituting the potential environmental impact from the system studied. Case studies were performed for i) road construction with or without MSWI bottom ash, ii) three management scenarios for MSWI bottom ash and iii) three management scenarios for wood ash. Different types of potential environmental impact predominated in the activities of the system and the scenarios differed in use of resources and energy. Utilising MSWI bottom ash in road construction and recycling of wood ash on forest land saved more natural resources and energy than when these materials were managed according to the other scenarios investigated, including dumping in landfill. There is a potential for trace element leaching regardless of how the ash is managed.Trace element leaching, particularly of copper (Cu), was identified as being relatively important for environmental assessment of MSWI bottom ash utilisation. CuO is suggested as the most important type of Cu-containing mineral in weathered MSWI bottom ash, whereas in the leachate Cu is mainly present in complexes with dissolved organic matter (DOM). The hydrophilic components of the DOM were more important for Cu binding than previously understood. Differences were also observed between MSWI bottom ash DOM and the natural DOM for which the geochemical speciation models SHM and NICA-Donnan are calibrated. Revised parameter values for speciation modelling are therefore suggested. Additions of salt or natural DOM in the influent did not change the leachate concentration of Cu. Thus, although Cl and natural DOM might be present in the influent in the field due to road salting or infiltration of soil water, this is of minor importance for the potential environmental impact from MSWI bottom ash.This thesis allows estimates of long-term leaching and toxicity to be improved and demonstrates the need for broadening the system boundaries in order to highlight the trade-offs between different types of impact. For decisions on whether incinerator residues should be utilised or landfilled, the use of a life cycle perspective in combination with more detailed assessments is recommended. / QC 20100914

This thesis describes improvements on newly-discovered high-strength pozzolan-based materials fabricated via a low-cost chemical reaction that takes place between 90 and 115 ℃ for 3 to 24 hours. The reported results focus on pozzolan constituents acquired from Coal Combustion Products (CCPs) such as cenospheres, fly ash C and F, as well as bottom ash. The thesis reports on various types of these materials with specific gravity ranging from 0.5 to 1.6; compressive strength ranging from 300 to 3600 psi, and compressive modulus ranging from 50 to 240 ksi. In addition to their good mechanical properties under compression that are attractive for the building and construction industries, the materials further exhibit great potential for applications as energy absorption cores in sandwich construction that could extend their value in other industries including the automotive and aerospace industries. For example, the load-displacement curve exhibits a short elastic zone followed by a long load-plateau; while the materials crush through a controlled vertical cracking process. Additionally, an attempt was made to further decrease the manufacturing cost of the material by investigating incorporation of chemicals that accelerates dehydration of the mixture. One such successful chemical reported in this thesis is aluminum phosphate; while it is not conclusive how the chemical improves any major property.

The purpose of this project was to produce a “greener” cement from granulated ground blast furnace slag (GGBS) using non-Portland cement activation. By eventually developing “greener” cement, the ultimate goal of this research project would be to reduce the amount of Portland cement used in concrete, therefore reducing the amount of carbon dioxide emitted into the atmosphere during cement production. This research studies the behavior of mineral binders that do not contain Portland cement but instead comprise GGBS activated by calcium compounds or fluidized bed combustion (FBC) bottom ash. The information described in this paper was collected from experiments including calorimetry, which is a measure of the release of heat from a particular reaction, the determination of activation energy of cement hydration, mechanical strength determination, and pH measurement and identification of crystalline phases using X-ray diffraction (XRD). The results indicated that it is possible to produce alkali-activated binders with incorporated slag, and bottom ash, which have mechanical properties similar to ordinary Portland cement (OPC). It was determined that the binder systems can incorporate up to 40% bottom ash without any major influence on binder quality. These are positive results in the search for “greener cement”.

A produção de cimento gera um impacto ambiental negativo, principalmente relacionado à emissão de dióxido de carbono (CO2). O clínquer do cimento sulfoaluminato de cálcio belítico (CSAB) possui um menor teor de óxido de cálcio e é produzido com uma reduzida temperatura de sinterização (aproximadamente 200ºC a menos em relação ao clínquer Portland), sendo considerado mais eco-amigável. Para a produção do cimento CSAB são necessárias matérias-primas ricas em alumínio e convencionalmente a bauxita é o minério utilizado para compor a farinha, o que mais onera a produção desse tipo de cimento. Soma-se ainda o fato que a geração de resíduos e subprodutos industriais torna-se inerente aos processos e o coprocessamento de resíduos vem sendo cada vez mais utilizado por razões ambientais e energéticas. Logo, fontes alternativas de alumina são fundamentais para a viabilização deste cimento e o aproveitamento de resíduos agregaria um valor econômico e sustentável ao produto final. De modo estequiométrico, a bauxita pode ser completamente substituída pelo lodo de anodização do alumínio (LAA), o qual também pode complementar o conteúdo de alumínio de outros resíduos, valorizando-os. O objetivo deste estudo foi avaliar a produção e as propriedades de clínqueres/cimentos CSAB a partir da substituição da bauxita por cinza pesada e LAA. Para a caracterização das matérias-primas, clínqueres e cimentos nos estados anidro e hidratado foram utilizadas as seguintes técnicas: fluorescência de raios X; microscopia eletrônica de varredura e espectrometria por energia dispersiva; termogravimentria; calorimetria; e difração de raios X com refinamento pelo método de Rietveld. A partir dos resultados obtidos, a substituição da bauxita foi limitada a nível parcial devido à elevada formação de belita e periclásio. Nos clínqueres produzidos, foi constatado que a presença da cinza pesada favorece a formação da estrutura cristalina ortorrômbica da fase ye’elimita. A presença dos resíduos altera a quantificação das fases, porém não compromete a estabilização das mesmas. A presença dos resíduos na composição dos cimentos afeta o período inicial de hidratação devido à redução do conteúdo de ye’elimita. Nos clínqueres produzidos com cinza pesada, ocorre a formação de até 12,6% da fase alita a 1250ºC, principal constituinte do clínquer Portland. / Cement production generates high negative environmental impact, mainly associated to CO2 emissions. Calcium sulfoaluminate belite cement clinker (CSAB) has lower content of calcium oxide, and sintering reduced temperature (about 200°C lower than that used for Portland clinker), being considered as eco-friendly binder. For its production high amount of alumina is required, however the scarcity and high cost of bauxite make these cements costly. Additionally, the generation of waste and by-products becomes a drawback in the industrial processes and the coprocessing of wastes in cement plants is increasing for environmental and energy savings reasons. Alternative sources of alumina would add an economic and sustainable value to the final product and previous work has shown that the aluminum anodizing sludge can replace bauxite in the production process. Other sources of wastes can also be a possibility to increase the production and reduce the raw materials costs of these cements. Thus, the objective of this study was the evaluation of novel CSAB cements produced with bauxite replacement by bottom ash and aluminum anodizing sludge. CSAB cements were produced in the laboratory from different amounts of sludge and ashes. The raw materials, clinkers/cements and hydration products were physicaly-chemicaly and mechanical characterized. Results showed that the mineralogy composition of CSAB clinker was strongly affected due to the addition of bottom ash. The amount of bottom ash waste replacing bauxite controls the belite and periclase formation. Also it influences the early age hydration due the reduced ye’elimite formation and important changes in the crystalline structures of this phase occurs in the clinkers. Clinkers prepared from these replacement, are able to form 12.6% of alite (main phase Portland clinker), not normally found in CSAB clinkers, being sintered at 1250°C.

Com a crescente ideia de sustentabilidade, surge a necessidade de utilização de recursos renováveis e reaproveitamento de resíduos gerados em processos industriais. Neste trabalho foi avaliada a utilização da cinza pesada oriunda da queima do carvão em usinas termoelétricas no desenvolvimento de um Cermet. O compósito Cinza-Ferro (Cz-10Fe) foi obtido por metalurgia do pó e é composto de cinza pesada moída com adição de 10% em massa de pó de ferro puro. A adição do ferro é justificada para melhoria das propriedades mecânicas do material cerâmico. O compósito foi aplicado como meio suporte para biofilme em filtro biológico percolador, no pós-tratamento de efluentes domésticos. Foram realizados estudos com os principais componentes da cinza, tais como a sílica (SiO2), em forma de pó de quartzo, e a alumina (Al2O3) na versão comercial para avaliação da interação dos mesmos com o ferro e avaliação de suas propriedades mecânicas sob influência da variação da temperatura de sinterização A cinza pesada, obtida na Usina Tractebel de Charqueadas, foi moída durante 2, 4 e 8 horas para determinação do tamanho de partícula ideal para o compósito. Após caracterização, foi selecionada cinza moída por 2 horas para a produção dos compósitos para aplicação. A aplicação se deu utilizando um protótipo no pós-tratamento de efluentes da Estação de Tratamento de Esgotos (ETE) da COMUSA visando a remoção de Demanda Química de Oxigênio (DQO). Obteve-se incremento na eficiência do processo, reduzindo a DQO do efluente final em média 9%, indicando a viabilidade de uso do protótipo no pós- tratamento de esgotos domésticos, com porosidade aproximada de 20%, obtidos na cinza moída por 2 horas e sinterizado com ferro, como meio suporte para biofilme em filtro biológico percolador. / With the crescent idea of sustainability, there is a necessity for the use of renewable resources and the reuse of waste generated in industrial processes. In this work the use of the coal bottom ash from thermoelectric plants was evaluated in the development of a Cermet. The composite Ash-Iron (Cz-10Fe) was obtained by powder metallurgy and is composed of ground heavy ash with addition of 10% by mass of pure iron powder. The addition of iron is justified to improve the mechanical properties of the ceramic material. The composite was applied as biofilm packing media in trickling filter in the post-treatment of domestic effluents. Studies with the main components of the ash, such as silica (SiO2), in the form of quartz powder, and alumina (Al2O3) in the commercial version were carried out to evaluate their interaction with iron and evaluation of their mechanical properties under influence of the sintering temperature variation The bottom ash obtained at Tractebel from Charqueadas was milling for 2, 4 and 8 hours to determine the ideal particle size for the composite. After characterization, milled ash for 2 hours was selected for the production of the composites for application. The application was done using a prototype in the post-treatment of effluents from the Wastewater Treatment Station (ETE) of COMUSA aiming at the removal of Chemical Oxygen Demand (COD). The efficiency of the process was obtained by reducing the COD of the final effluent by a mean of 9%, indicating the viability of the utilization the prototype in the post-treatment of domestic sewage, with approximate porosity of 20%, obtained in ground ash for 2 hours and sintered with iron powder, in biofilm packing media in trickling filter.

A produção de cimento gera um impacto ambiental negativo, principalmente relacionado à emissão de dióxido de carbono (CO2). O clínquer do cimento sulfoaluminato de cálcio belítico (CSAB) possui um menor teor de óxido de cálcio e é produzido com uma reduzida temperatura de sinterização (aproximadamente 200ºC a menos em relação ao clínquer Portland), sendo considerado mais eco-amigável. Para a produção do cimento CSAB são necessárias matérias-primas ricas em alumínio e convencionalmente a bauxita é o minério utilizado para compor a farinha, o que mais onera a produção desse tipo de cimento. Soma-se ainda o fato que a geração de resíduos e subprodutos industriais torna-se inerente aos processos e o coprocessamento de resíduos vem sendo cada vez mais utilizado por razões ambientais e energéticas. Logo, fontes alternativas de alumina são fundamentais para a viabilização deste cimento e o aproveitamento de resíduos agregaria um valor econômico e sustentável ao produto final. De modo estequiométrico, a bauxita pode ser completamente substituída pelo lodo de anodização do alumínio (LAA), o qual também pode complementar o conteúdo de alumínio de outros resíduos, valorizando-os. O objetivo deste estudo foi avaliar a produção e as propriedades de clínqueres/cimentos CSAB a partir da substituição da bauxita por cinza pesada e LAA. Para a caracterização das matérias-primas, clínqueres e cimentos nos estados anidro e hidratado foram utilizadas as seguintes técnicas: fluorescência de raios X; microscopia eletrônica de varredura e espectrometria por energia dispersiva; termogravimentria; calorimetria; e difração de raios X com refinamento pelo método de Rietveld. A partir dos resultados obtidos, a substituição da bauxita foi limitada a nível parcial devido à elevada formação de belita e periclásio. Nos clínqueres produzidos, foi constatado que a presença da cinza pesada favorece a formação da estrutura cristalina ortorrômbica da fase ye’elimita. A presença dos resíduos altera a quantificação das fases, porém não compromete a estabilização das mesmas. A presença dos resíduos na composição dos cimentos afeta o período inicial de hidratação devido à redução do conteúdo de ye’elimita. Nos clínqueres produzidos com cinza pesada, ocorre a formação de até 12,6% da fase alita a 1250ºC, principal constituinte do clínquer Portland. / Cement production generates high negative environmental impact, mainly associated to CO2 emissions. Calcium sulfoaluminate belite cement clinker (CSAB) has lower content of calcium oxide, and sintering reduced temperature (about 200°C lower than that used for Portland clinker), being considered as eco-friendly binder. For its production high amount of alumina is required, however the scarcity and high cost of bauxite make these cements costly. Additionally, the generation of waste and by-products becomes a drawback in the industrial processes and the coprocessing of wastes in cement plants is increasing for environmental and energy savings reasons. Alternative sources of alumina would add an economic and sustainable value to the final product and previous work has shown that the aluminum anodizing sludge can replace bauxite in the production process. Other sources of wastes can also be a possibility to increase the production and reduce the raw materials costs of these cements. Thus, the objective of this study was the evaluation of novel CSAB cements produced with bauxite replacement by bottom ash and aluminum anodizing sludge. CSAB cements were produced in the laboratory from different amounts of sludge and ashes. The raw materials, clinkers/cements and hydration products were physicaly-chemicaly and mechanical characterized. Results showed that the mineralogy composition of CSAB clinker was strongly affected due to the addition of bottom ash. The amount of bottom ash waste replacing bauxite controls the belite and periclase formation. Also it influences the early age hydration due the reduced ye’elimite formation and important changes in the crystalline structures of this phase occurs in the clinkers. Clinkers prepared from these replacement, are able to form 12.6% of alite (main phase Portland clinker), not normally found in CSAB clinkers, being sintered at 1250°C.

Com a crescente ideia de sustentabilidade, surge a necessidade de utilização de recursos renováveis e reaproveitamento de resíduos gerados em processos industriais. Neste trabalho foi avaliada a utilização da cinza pesada oriunda da queima do carvão em usinas termoelétricas no desenvolvimento de um Cermet. O compósito Cinza-Ferro (Cz-10Fe) foi obtido por metalurgia do pó e é composto de cinza pesada moída com adição de 10% em massa de pó de ferro puro. A adição do ferro é justificada para melhoria das propriedades mecânicas do material cerâmico. O compósito foi aplicado como meio suporte para biofilme em filtro biológico percolador, no pós-tratamento de efluentes domésticos. Foram realizados estudos com os principais componentes da cinza, tais como a sílica (SiO2), em forma de pó de quartzo, e a alumina (Al2O3) na versão comercial para avaliação da interação dos mesmos com o ferro e avaliação de suas propriedades mecânicas sob influência da variação da temperatura de sinterização A cinza pesada, obtida na Usina Tractebel de Charqueadas, foi moída durante 2, 4 e 8 horas para determinação do tamanho de partícula ideal para o compósito. Após caracterização, foi selecionada cinza moída por 2 horas para a produção dos compósitos para aplicação. A aplicação se deu utilizando um protótipo no pós-tratamento de efluentes da Estação de Tratamento de Esgotos (ETE) da COMUSA visando a remoção de Demanda Química de Oxigênio (DQO). Obteve-se incremento na eficiência do processo, reduzindo a DQO do efluente final em média 9%, indicando a viabilidade de uso do protótipo no pós- tratamento de esgotos domésticos, com porosidade aproximada de 20%, obtidos na cinza moída por 2 horas e sinterizado com ferro, como meio suporte para biofilme em filtro biológico percolador. / With the crescent idea of sustainability, there is a necessity for the use of renewable resources and the reuse of waste generated in industrial processes. In this work the use of the coal bottom ash from thermoelectric plants was evaluated in the development of a Cermet. The composite Ash-Iron (Cz-10Fe) was obtained by powder metallurgy and is composed of ground heavy ash with addition of 10% by mass of pure iron powder. The addition of iron is justified to improve the mechanical properties of the ceramic material. The composite was applied as biofilm packing media in trickling filter in the post-treatment of domestic effluents. Studies with the main components of the ash, such as silica (SiO2), in the form of quartz powder, and alumina (Al2O3) in the commercial version were carried out to evaluate their interaction with iron and evaluation of their mechanical properties under influence of the sintering temperature variation The bottom ash obtained at Tractebel from Charqueadas was milling for 2, 4 and 8 hours to determine the ideal particle size for the composite. After characterization, milled ash for 2 hours was selected for the production of the composites for application. The application was done using a prototype in the post-treatment of effluents from the Wastewater Treatment Station (ETE) of COMUSA aiming at the removal of Chemical Oxygen Demand (COD). The efficiency of the process was obtained by reducing the COD of the final effluent by a mean of 9%, indicating the viability of the utilization the prototype in the post-treatment of domestic sewage, with approximate porosity of 20%, obtained in ground ash for 2 hours and sintered with iron powder, in biofilm packing media in trickling filter.

Ce travail de recherche s'inscrit dans une dynamique de valorisation des sous-produits industriels locaux dans l'industrie cimentière. Il porte essentiellement sur la possibilité d'utiliser la poudre de mâchefer de charbon produit par la SONICHAR au Niger pour élaborer des ciments composés. Après une caractérisation physico-chimique et environnementale de la poudre de mâchefer, nous avons déterminé sa réactivité pouzzolanique et son indice d'activité mécanique. Les résultats montrent que la poudre de mâchefer présente une pouzzolanicité dont la cinétique relativement lente ne démarre pas avant 14 jours. D'autre part, ce mâchefer peut être considéré comme une addition minérale du type Il selon la norme EN 206-1 avec un indice d'activité de 0,76. C'est pourquoi nous l'avons utilisé pour élaborer trois ciments composés de type CEM 11/A avec une classe de résistance de 42,5 lorsque le taux de substitution est de 10% et une classe de résistance de 32,5 lorsque Je taux de substitution est de 15% et 20%. Des mortiers normaux ont été élaborés à partir de ces ciments et caractérisés sur les plans physiques et mécaniques. La durabilité des mortiers a également été étudiée notamment du point de vue de la cinétique de carbonatation et de lixiviation en présence de nitrate d'ammonium. Il ressort en définitive que la poudre de mâchefer peut bien être incorporée comme addition dans l’élaboration de ciments composés. Les caractéristiques mécaniques à long terme (90 jours) et la durabilité des mortiers confectionnés à partir de ces ciments sont conservées lorsque le taux de substitution n'excède pas 10%. / This research is part of a process of valorization of local industrial by-products in the cement industry. lt focuses on the possibility f using coal bottom ash powder produced by SONICHAR in Niger as cement partial addition. After a physicochemical and environmental characterization of the coal bottom ash powder, we determined its pozzolanic reactivity and it mechanical activity index. The results show that the coal bottom ash powder presents a pozzolanicity whose relatively slow kinetics do ne start before 14 days. On the other hand, this coal bottom ash can be considered as a mineral addition of type 11 according to the standard EN 206-1 with an activity index of 0.76. This is why we used it to develop three CEM 11/A composite cements with a strength class of 42.5 when the substitution rate is 10% and a strength class of 32.5 when the rate of substitution is 15% and 20%. Normal mortars have been formulated with these cements and are characterized physically and mechanically. The durability of the mortars has also been studied, in particular from the point of view of the kinetics of carbonation and leaching in the presence of ammonium nitrate. Finally, it appears that the coal bottom ash powder may indeed be incorporated as an addition in the preparation of composite cements. The long-term mechanical characteristics (90 days) and the durability of the mortars made from these cements are preserved when the substitution rate does not exceed 10%.

Shredder fines are the materials with a particle size of less than 10 mm resulting from the shredding of vehicles and complex metal scrap from industries and municipalities. This waste is currently used as landfill construction material, but Stena Recycling wanted to know whether the bottom ash from the combustion of this waste could be useful to the cement industry, and whether it would be feasible to extract Cu and Zn from this ash. To determine this the shredder fines were combusted, and the generated bottom ash underwent chemical fractionation. The leachates from this were processed using MP-AES to obtain an elemental analysis of the ash. The uncombusted shredder fines had its moisture content and calorific value determined. The shredder fines had a moisture content of approximately 11%wt. Due to the heterogeneity of the shredder fines the calorific values varied significantly across the tested samples. The average value was 7.8 MJ/kg. The chemical fractionation showed that the elements in the ash are mostly insoluble in water and ammonium acetate, as the majority remained in the solid residue. This indicates that the ash is inert, and not susceptible to heavy metal leaching. The elemental analysis showed that there is a significant amount of Fe in the ash, with reasonable amounts of Cu and Zn. This project concluded that without additional processing the ash would not be suitable for the cement industry, and that there is potential for the recovery of Cu and Zn from the ash.

Bottom ash (BA), generated from the incineration of municipal solid waste (MSW), contains valuable elements which present a potential economic incentive to attempt recovery. The first study of this thesis investigated the physical, chemical, and mineralogical characterization of MSWI-BA samples through a number of experiments. To develop a proper physical characterization of the BA material, the sample was ground and subjected to particle size distribution, wet magnetic separation, and a float-sink test. As for the chemical and mineralogical characterization, the sample was subjected to XRD, XRF, SEM-EDX, and elemental composition analysis. Additionally, sequential chemical extraction and acid-leaching tests were conducted. The results from this section revealed that carrying out a combination of beneficiation processes using the MSWI-BA sample previously classified into the coarse, middle, and fine-size fractions could lead to better metal concentration yield and recovery optimization. The wet magnetic separation showed outstanding metallurgy indicators towards Fe, with enrichment ratios close to 2.0 and recovery values near to 80%. Metals such as Cu and Co were also enriched by 1.51 and 1.66, respectively, suggesting that the magnetic separation performance and enrichment are a function of the bound of multi-metallic oxides fractions. The 2.95 SG density test reached enrichment ratios higher than 2.0 in Fe, Cu, Co, and Ni in the coarse fraction of the BA fraction, which decreases when reducing the size fraction. When reducing the density cutoff, the results showed that the sink fraction yield increased as the medium density decreased, and the enrichment ratios of the minor elements (Mn, Co, Ni, Sn, and V) were similar across the different size fractions. Complementary information was obtained by the mineralogical characterization of the enriched streams from the physical concentration test, which explains the results obtained. The Cu speciation and mineral phases identified were copper oxide, copper sulfate, and cupric sulfite. While the main Fe-rich constituents existed in chemical forms of iron oxides, such as magnetite, hematite with substituted varieties, spinel group, and metallic inclusions. The enrichment ratios of Mn, Cr, Cu, and Ni obtained through magnetic separation can be explained by the presence of metallic inclusions, where these elements exhibit an affinity for the iron-bearing particles. The acid leaching test revealed that metals such as Fe, Mn, Co, Cu, and Zn can be efficiently leached using 1M HCl within 30 min of the reaction. The second part of this research study constituted the evaluation of the effect of the particle size reduction, which was performed to assess the intraparticle heterogeneity of MSWI BA. The evaluation consisted of particle size reductions by crushing and grinding for different residence times and then subjecting the sample to a sequence of physical concentration tests, such as particle size distribution, froth flotation, and wet magnetic separation. Additionally, the elemental composition after each test was determined through ICP-MS analysis to compare the particle size effect in the recovery and concentration of the valuable elements. The elemental composition results revealed that the comminution process promotes the interaction of Fe, Zn, and Cu, in the fine fraction, by generating more surface area. In contrast, the minor elements were not significantly enriched by reducing the size fraction, suggesting that the comminution process does not impact the mobility and redistribution of the elements in low concentrations. The froth flotation performed in this study showed that when using 0.338 g/ton diesel as a collector, adjusting and controlling the pH between 8.8 to 9.2 throughout the test, the organic matter content can be efficiently reduced in the BA sample from 14.73% to 4.25% when the sample has been previously ground for 30 min. Slight enrichment ratios were observed in the concentrate stream of the froth flotation, suggesting that these elements are associated with the organic matter in the BA sample. In contrast, the wet magnetic separation results revealed significant enrichment ratios of Fe, Mn, Co, and Ni after 10 min of grinding. / Master of Science / The Bottom Ash (BA) generated by the incineration of household solid waste has been identified as a promising source of valuable elements. However, a comprehensive understanding of the BA sample's properties is required in order to determine the most suitable mineral processing method to enrich the elements. The first study of this research consisted of evaluating BA ash's physical, chemical, and mineralogical properties in the BA sample. Following the characterization study, the effect of particle size, as a function of the grinding time, in the valuable elements' enrichment was evaluated. The results suggest that Ti, Fe, Cu, and Zn are the major and most valuable elements, while Mn, Co, Ni, Sb, and V are valuable elements in a minor concentration in the BA samples. Some elements, such as Ti, Sc, Co, Mn, Ni, Sn, and V, have been declared by the US Department of the Interior as critical minerals due to their economic importance and vulnerability to supply chain disruption. Although Fe and Cu are not considered critical minerals, their consumption in 2022 was 40 and 1.9 million metric tons, respectively. The development of national industry and enhancing the understanding of the alternative sources for the valuable elements present an opportunity to diversify local suppliers, pursue a vertical integration of the economic model, and reduce the third-party international vendors' dependency. Likewise, this research supports the aims to reduce the demand for primary natural resources and contribute to the circular economy model, in which energy, resources, and material are kept in a lifecycle while reducing landfilling disposal.