Tegeltillverkning har i industriell form funnits på Gotland i över 100 år. Mellan 1903–1970 fanns det ett Tegelbruk i Havdhem som kom att dominera den gotländska marknaden. Tegelproduktionens utveckling övertid har lokalt speglat hur det har sett ut nationellt men i mindre skala. Den har även påverkats mycket av den lokala näringsutvecklingen. Havdhems tegelbruk startades på samhällsaktörers initiativ för att hjälpa det ökade behovet av tegelrör för täckdikning. Tegelrören kom att bli den viktigaste produkten för bruket som även tillverkade murtegel, håltegel och fasadtegel. Tegelbrukets produktionsvolym under dess glansperiod låg på 3 miljoner per år och hade 25 årsanställda. Den centrala orsaken till brukets nedläggning var en kraftig brand i december 1970.   Havdhemsteglet bestod av en lera med låg järnoxidhalt vilket resulterade i ett ljusrött tegel. Leran hämtades lokalt från tre olika lertag. Bruket har tillverkat både rött och gult tegel och har köpt in råmaterial för att påverka färgen. Ett av byggnadsverken som stoltserar med Havdhemstegel är Visby vattenledningstorn som byggdes 1925. Vattenledningstornet är byggt med det för Havdhem typiska ljusröda teglet. / Brick manufacturing in industrial form has been used on Gotland for over 100 years. Between 1903 and 1970, there was a tilery in Havdhem, in the south of Gotland, that came to dominate the Gotlandic market. The brick productions development has locally reflected how it has looked nationally but on a smaller scale. The brick industry has also been influenced by the local business development. Havdhems tilery was started through community-active initiatives to help increase the need for brick pipes for field drainage. The brick pipes became the most important product for the factory. The tilery also manufactured several different kinds of bricks. The tilery’s production volume during its high period was 3 million per year and had 25 full-time employees. The central reason for the closure of the factory was a severe fire in December 1970.   Havdhems bricks consisted of a clay composition with a low iron-oxide content which creates a lighter red brick. The clay was sourced locally from three different clay quarries. The factory has manufactured both red and yellow bricks and has purchased raw materials to influence the color. One of the buildings that boasts Havdhems clay bricks is the Visby water conduit tower, which was built in 1925. The water conduit tower was built with the representative light red brick.

This thesis is focused on the possibilities of the utilization of the fludized fly ash in ceramic technology, especially in the field of brick manufacturing and ceramic tiles. There were used fly ashes from thermal power plants in Hodonín, Ledvice and Tisová. Fluidized fly ash can be used for manufacturing of building materials. There hasn’t been done extensive research in this area. One of the problem is sulphur dioxide leakage during burning. The work describes the behaviour of fluidized ash during firing. The attention is focused on air pollution of sulphur dioxide. The production of SO2 is controlled so that the aim of the work is to find a way how to avoid leaking. It was proved that addition of sodium ions causes the formation of minerals hauyne and nosean during firing. Also is described the behaviour of the fly ash-soil mixtures. The anhydrite decomposition temperature is lower than in pure fly ash. In the end is fluidized ash applied for the production of dry pressed ceramic tiles. This ash can be used in ceramic technology. However, despite the interesting results there are number of problems that need to be solved.

Este proyecto se centra en evaluar la prefactibilidad de una fábrica de ladrillos a base de PET con el propósito de satisfacer la demanda en la región Lambayeque. El estudio ha arrojado resultados positivos desde el punto de vista comercial técnico y económico. Para cumplir con los objetivos trazados primero se tuvo que determinar la viabilidad comercial del proyecto, para lograrlo se realizó un estudio de mercado, en el cual se realizó el análisis del comportamiento de la demanda y oferta, los resultados revelan una demanda proyectada para los próximos 5 años que alcanza hasta 9 millones de soles en ventas, lo que respalda la viabilidad comercial del proyecto. Seguidamente para el segundo objetivo se evaluó la viabilidad de la producción de ladrillos PET y se desarrolló un plan de producción que prevé la fabricación de 9,521 mil ladrillos para el quinto año de operación. Estos datos confirman la viabilidad técnica del proyecto. Paralelamente, se realizó la selección del lugar se llevó a cabo mediante un enfoque basado en factores ponderados, y la ubicación óptima resultó ser la provincia de Lambayeque, específicamente en la carretera, con un puntaje de 466.66. Este proceso asegura una ubicación estratégica para la fábrica. Después se hallaron las áreas correspondientes con el método Guerchet y el (SPL). Para finalizar se revela que el proyecto es no solo viable, sino también rentable con un Valor Actual Neto (VAN) de S/1 779 831,08 y una Tasa Interna de Retorno (TIR) del 52%, se confirma la solidez financiera del proyecto. / This project focuses on evaluating the prefeasibility of a PET-based brick factory with the purpose of satisfying the demand in the Lambayeque region. The study has yielded positive results from a technical and economic commercial point of view. To meet the established objectives, the commercial viability of the project had to be determined first. To achieve this, a market study was carried out, in which the analysis of the behavior of demand and supply was carried out. The results reveal a projected demand for the next few years. 5 years that reaches up to 9 million soles in sales, which supports the commercial viability of the project. Next, for the second objective, the viability of the production of PET bricks was evaluated and a production plan was developed that foresees the manufacture of 9,521 thousand bricks for the fifth year of operation. These data confirm the technical feasibility of the project. In parallel, the site selection was carried out using an approach based on weighted factors, and the optimal location turned out to be the province of Lambayeque, specifically on the highway, with a score of 466.66. This process ensures a strategic location for the factory. Then the corresponding areas were found with the Guerchet method and the (SPL). Finally, it is revealed that the project is not only viable, but also profitable with a Net Present Value (NPV) of S/1,779,831.08 and an Internal Rate of Return (IRR) of 52%, the financial solidity of the project is confirmed. project.

La forte augmentation de la population mondiale entraîne une demande croissante en eau potable. La production d'eau potable est accompagnée par la génération de résidus du traitement de l'eau dont la boue d'aluminium qui est donc largement disponible mondialement. Ce travail se concentre sur l'identification des différentes voies de valorisation des boues d'aluminium afin de les réutiliser dans le domaine de l’environnement. Deux sources de boues d'aluminium, collectées en France et en Irlande, ont été étudiées dans divers domaines d’application en fonction de leurs caractéristiques. Tout d'abord, les boues d'aluminium ont été utilisées en remplacement d’une partie de l'argile dans la fabrication des briques, en incorporant différents pourcentages de boues d'aluminium et à différentes températures. Les briques résultantes ont été caractérisées et les résultats ont montré que les briques composées de boues d'aluminium et d'argile sont conformes aux « normes européennes et irlandaises » et démontrent ainsi le potentiel pour une application industrielle des boues d'aluminium dans la fabrication de briques en terre cuite irlandaises. Dans un second temps, les boues d’aluminium ont été utilisées comme adsorbant des polluants présents dans l’agriculture. Le glyphosate est un ingrédient actif dans les pesticides utilisés massivement dans l'agriculture irlandaise et représente une problématique environnementale. La boue d’aluminium et la tourbe irlandaise ont été comparées pour l’élimination du glyphosate lors de tests en pot à l’échelle laboratoire. Les résultats ont montré que la boue d’aluminium permet d’éliminer le glyphosate à plus de 99% et réduire les niveaux de DCO. Cet aspect scientifique a permis d’être dans la sélection des adsorbants possibles pour le traitement des eaux usées agricoles en Irlande. Le co-conditionnement et la déshydratation des boues de station d’épuration avec des boues d’aluminium liquides ont également été étudiés. Pour cela, le Jar test a été effectué sur des boues issues d’une station de traitement des eaux française. Les résultats ont montré que le rapport optimal de mélange des boues est de 1:1 (boues d’épuration : boues d’aluminium). Ainsi, la quantité de polymère utilisée peut être diminuée de 14 fois par rapport aux technologies actuelles. Cette approche a permis de montrer la possible valorisation des boues d’aluminium comme un moyen durable et technique permettant ainsi l’élimination des boues localement pour une même station de traitement des eaux. Une autre voie de valorisation des boues d’aluminium comme adsorbant pour la purification des gaz a été étudiée lors d’expériences d’adsorption de H2S dans un réacteur à lit fixe dans différentes conditions expérimentales. Les données expérimentales d’adsorption du H2S ont été modélisées à l'aide de modèles empiriques basés sur la cinétique des processus d'adsorption. Les résultats ont montré que les boues d'aluminium sont un adsorbant efficace pour l'élimination du H2S (capacité de 374,2 mg H2S / g solide) et que des mécanismes mis en jeu sont l'adsorption dissociative et l'oxydation. Les coefficients de transfert de masse globaux ont également été calculés et pouvant ainsi être utilisés pour la prédiction. Enfin, les gâteaux de boues d'aluminium ont été réutilisés pour la purification simultanée d’H2S et le traitement des eaux usées. Les résultats ont montré la capacité de cet adsorbant pour éliminer tout le H2S présent avec une grande efficacité d’élimination de la DCO, TN et TP. Ainsi, il a été démontré la valorisation des boues d’aluminium en tant qu’adsorbant pour une purification du H2S simultanée avec le traitement des eaux usées. / The production of drinking water always accompanied by the generation of water treatment residues (WTRs). Alum sludge is one of the WTRs, it is an easily, locally and largely available by-product worldwide. This work focuses on the identification of different ways to valorize the alum sludge for environmentally friendly reuse. Two alum sludges collected from France and Ireland have been reused in various fields as a function of their characteristics. Firstly, alum sludge was used as a partial replacement for clay in brick making, by incorporating different percentages of alum sludge and calcined at different temperatures (range from 800 to 1200 °C). The resultant bricks were tested for compression, Loss on Ignition, water absorption, appearance, etc. Results show that alum sludge-clay bricks have met the “European and Irish Standards” and demonstrated the huge industrial application potential for alum sludge in Irish clay brick manufacturing. Glyphosate is an active ingredient in pesticide which is massive employed in agriculture. Alum sludge and Irish peat were compared for glyphosate removal in pot tests, results show that alum sludge present significant glyphosate removal capacity (>99 %) and could reduce the level of Chemical Oxygen Demand (COD). It provided a scientific clue for sorbents selection when considering the agricultural wastewater treatment in Ireland and to maximize their value in practice. The co-conditioning and dewatering of sewerage sludge with liquid alum sludge was also investigated in Jar-test based on the case analysis of a water industry in France. Results show that the optimal sludge mix ratio is 1:1, the use of the alum sludge has been shown to beneficially enhance the dewaterability of the resultant mixed sludge, and highlighting a huge polymer saving (14 times less than the current technologies) and provided a sustainable and technical sludge disposal route for the local water industry. The use of alum sludge as a sorbent for gas purification was studied by H2S adsorption experiments in a fixed-bed reactor with various operating parameters. The experimental breakthrough data were modeled with empirical models based on adsorption kinetics. Results show that alum sludge is an efficient sorbent for H2S removal (capacity of 374.2 mg/g) and the mechanisms including dissociative adsorption and oxidation were proposed. Moreover, the overall mass transfer coefficients were calculated which could be used for the process scaling up. Finally, alum sludge cakes were reused in the novel aerated alum sludge constructed wetland (CW), which were designed for simultaneous H2S purification and wastewater treatment. Results show that H2S was completely removed in the six months’ trials, while the high removal efficiencies of COD, total nitrogen (TN), total phosphates (TP) were achieved. Thus, a novel eco-friendly CW for simultaneous H2S purification and wastewater treatment was developed. In the different approaches and process considered, in particular it was put in investigating and describing the mechanisms involved. Overall, this work demonstrated alum sludge could be a promising by- product for various novel beneficial reuse rather than landfilling and provided a “Circular Economy” approach for WTRs management.

MESMEG / Department of Mining and Environmental Geology / Although clay brick manufacturing has been going on for many years in South Africa, informal small-scale clay brick manufacturing enterprises are not officially regulated. Consequently, informal brick makers in the study area do not adhere to the demanding requirements of the South African National Standards for burnt clay masonry. Therefore, their clay bricks lack uniformity in terms of quality. Preliminary work revealed that over time, buildings constructed with these bricks develop cracks, thereby compromising safety. The importance of product quality management is not well understood in the informal brick manufacturing enterprises. As a result, they do not have any product quality management guidelines. The main purpose of this research was to develop the product quality management guidelines for ensuring quality in small-scale brick making enterprises in Dididi area. The specific objectives were to characterize the raw materials for clay brick manufacturing, identify and assess the technical problems of clay brick production, analyse the process of clay brick production and determine areas where product quality improvement is warranted. The research involved fieldwork which included soil sampling, analysis of clay brick production through the use of questionnaires and onsite observation of the production process, collection of samples of burnt bricks which were examined for compressive strength, water absorption as well as dimension measurements. These were then compared with the prescribed quality standards. Laboratory analyses of samples of raw materials were conducted and these included sieve analysis which was conducted in order to establish the particle size distribution of the raw materials; Atterberg limit tests were conducted in order to establish the physical characteristics of the soil. Chemical and mineralogical analyses were carried out to determine the chemical and mineralogical composition of the soil using XRF and XRD respectively. The textural characterisation of the material revealed abundance of sand sized particles and significantly low amounts of clay and silt. The plasticity of the soil used for bricks manufacturing in the study area was found to be ranging from slight to medium plasticity. Chemical analysis showed elevated silica contents with minor amounts of alumina and iron oxide. XRD analysis revealed the dominance of non-clay minerals with the highest concentration of quartz. The average compressive strengths of the tested brick samples for site A was 3.8, and 2.9 and 3.8 MPa for sites B and C respectively. The water absorption of the bricks was 13.5, 15.0 and 16.1% for samples from Site A, B and C respectively. The bricks dimensions met the recommended standards although their sizes were not uniform. v The survey conducted on brick manufacturing process revealed that the technical inefficiencies were mostly influenced by human and mechanical factors as well as the material inappropriateness. The production process was found to be too manual and labour intensive. Selection of the raw materials for brick manufacturing was based on indigenous knowledge and experience and most of the brick manufacturers lacked the prerequisite experience for making quality bricks. On the basis of the results of this research, it can be concluded that the materials used for manufacturing of clay bricks in Dididi are not well suited for making good quality bricks due to the reduced plasticity of the soil and the high concentration of quartz. These render the bricks brittle. It was also concluded that the production process also contributes to the poor quality of the bricks as the nature of the process was too manual. Selection of materials based merely on knowledge and experience and no scientific tests resulted in selection of inadequate materials which in turn affect the quality of the final bricks. It is therefore recommended that plastic clays be added to the raw clay materials to enhance its moulding property. In addition, materials such as internal fuels and anti-shrinkage materials should be incorporated into the process cycle to prevent cracking during drying and firing. Based on the findings of the analysis of the production process, it is recommended that mechanized techniques be employed in the operation and awareness training conducted to improve the understanding and skills of the brick manufacturers and to ensure production of good quality bricks. / NRF