Naftos krekinge naudotas katalizatorius yra ceolitinė medžiaga, kurios unikalios savybės mažai išnaudojamos cementinių medžiagų gamybos technologijoje. Ugniai atspariuose betonuose naudojami įvairūs priedai-modifikatoriai yra labai brangūs, todėl naudoto katalizatoriaus panaudojimas, kaip modifikuojančio betono savybes priedo, turi ne tik ekologinį (atliekų utilizavimas) bet ir ekonominį pagrindą. Vykdant šį darbą sukurti vidutinio cemento kiekio ugniai atsparūs šamotbetoniai su 70 % ir 40 % aliuminio oksido turinčiais aliuminatiniais cementais ir naudoto katalizatoriaus priedu atitinkamai 2,5 % ir 5,0 %. Darbe taip pat atskleistas efektyvus katalizatoriaus poveikis aliuminatinio cemento hidratacijai, cemento akmens struktūros susidarymui kietėjimo metu ir jos pokyčiams veikiant aukštoms temperatūroms. / Fluidized bed catalytic cracking catalyst waste is a zeolite material. Its unique properties are underused in cementitious materials production technology. Various additives, modifiers used in refractory castables are very expensive, so the use of catalyst waste as a modifying additive of castable properties has not only an ecological (waste recycling) but also an economical basis. Medium cement refractory castable was developed using 70 % and 40 % of aluminium oxide containing aluminate cement and catalyst waste additive, respectively 2,5 % and 5,0 %. The work also reveals an efficient effect of catalyst waste on alumina cement hydration, structure formation during cement solidification and after treatment at high temperature.

A constante busca por redução de custos e alternativas estratégicas por abastecimento de insumos refratários, tem levado as usinas siderúrgicas à buscar novos fornecedores para atender suas necessidades. Com base na necessidade da Companhia Siderúrgica Nacional (CSN), firmou-se uma parceria entre universidade e empresa, com intuito de desenvolver um novo fornecedor para um insumo refratário o qual só era fornecido por uma empresa. Foi então iniciado um trabalho de investigação das propriedades físico-químicas do material utilizado pela CSN (material de referência), utilizando-se a análise da distribuição granulométrica, composição mineralógica e propriedades mecânicas. A partir deste ponto, convidouse uma empresa genuinamente nacional, para desenvolver um novo produto, com matérias primas nacionais, que tivesse as mesmas propriedades mecânicas do material de referência. O concreto nacional foi caracterizado da mesma forma que o material de referência, em suas propriedades físico-químicas e ensaios mecânicos. Com base nos resultados foi realizado um teste em escala piloto, com aprovação do material. A empresa parceira passou a ter um novo material em sua carteira de produtos comercializado no mercado nacional e a CSN está realizando testes em escala industrial para aprovar um novo fornecedor de concreto refratário de alta resistência mecânica. / The constant search for cost reduction and strategic alternatives for refractory raw materials supply, has led the steelplants to look for new suppliers to meet its needs. Companhia Siderurgica Nacional (CSN) has signed a partnership between universities and companies, aiming to develop a new supplier for a refractory raw material which was only supplied by one company. Then a research based on chemical-physical properties of material used by CSN (reference material) was started, using the analysis of particle size distribution, mineralogical composition and mechanical properties. From this point, a genuine national company was invited, to develop a new product, with national raw materials, which had the same mechanical properties of the reference material. The national castable was characterized in the same way as the reference material in their chemical-physical properties and mechanical tests. Based on the results a test was performed on a pilot scale, with the approval of the material. The partner company has taken on a new material in its portfolio of products marketed in the domestic market and CSN is conducting tests on an industrial scale to approve a new supplier of refractory concrete with high mechanical strength.

A constante busca por redução de custos e alternativas estratégicas por abastecimento de insumos refratários, tem levado as usinas siderúrgicas à buscar novos fornecedores para atender suas necessidades. Com base na necessidade da Companhia Siderúrgica Nacional (CSN), firmou-se uma parceria entre universidade e empresa, com intuito de desenvolver um novo fornecedor para um insumo refratário o qual só era fornecido por uma empresa. Foi então iniciado um trabalho de investigação das propriedades físico-químicas do material utilizado pela CSN (material de referência), utilizando-se a análise da distribuição granulométrica, composição mineralógica e propriedades mecânicas. A partir deste ponto, convidouse uma empresa genuinamente nacional, para desenvolver um novo produto, com matérias primas nacionais, que tivesse as mesmas propriedades mecânicas do material de referência. O concreto nacional foi caracterizado da mesma forma que o material de referência, em suas propriedades físico-químicas e ensaios mecânicos. Com base nos resultados foi realizado um teste em escala piloto, com aprovação do material. A empresa parceira passou a ter um novo material em sua carteira de produtos comercializado no mercado nacional e a CSN está realizando testes em escala industrial para aprovar um novo fornecedor de concreto refratário de alta resistência mecânica. / The constant search for cost reduction and strategic alternatives for refractory raw materials supply, has led the steelplants to look for new suppliers to meet its needs. Companhia Siderurgica Nacional (CSN) has signed a partnership between universities and companies, aiming to develop a new supplier for a refractory raw material which was only supplied by one company. Then a research based on chemical-physical properties of material used by CSN (reference material) was started, using the analysis of particle size distribution, mineralogical composition and mechanical properties. From this point, a genuine national company was invited, to develop a new product, with national raw materials, which had the same mechanical properties of the reference material. The national castable was characterized in the same way as the reference material in their chemical-physical properties and mechanical tests. Based on the results a test was performed on a pilot scale, with the approval of the material. The partner company has taken on a new material in its portfolio of products marketed in the domestic market and CSN is conducting tests on an industrial scale to approve a new supplier of refractory concrete with high mechanical strength.

Fluidized bed catalytic cracking catalyst waste is a zeolite material. Its unique properties are underused in cementitious materials production technology. Various additives, modifiers used in refractory castables are very expensive, so the use of catalyst waste as a modifying additive of castable properties has not only an ecological (waste recycling) but also an economical basis. Medium cement refractory castable was developed using 70 % and 40 % of aluminium oxide containing aluminate cement and catalyst waste additive, respectively 2,5 % and 5,0 %. The work also reveals an efficient effect of catalyst waste on alumina cement hydration, structure formation during cement solidification and after treatment at high temperature. / Naftos krekinge naudotas katalizatorius yra ceolitinė medžiaga, kurios unikalios savybės mažai išnaudojamos cementinių medžiagų gamybos technologijoje. Ugniai atspariuose betonuose naudojami įvairūs priedai-modifikatoriai yra labai brangūs, todėl naudoto katalizatoriaus panaudojimas, kaip modifikuojančio betono savybes priedo, turi ne tik ekologinį (atliekų utilizavimas) bet ir ekonominį pagrindą. Vykdant šį darbą sukurti vidutinio cemento kiekio ugniai atsparūs šamotbetoniai su 70 % ir 40 % aliuminio oksido turinčiais aliuminatiniais cementais ir naudoto katalizatoriaus priedu atitinkamai 2,5 % ir 5,0 %. Darbe taip pat atskleistas efektyvus katalizatoriaus poveikis aliuminatinio cemento hidratacijai, cemento akmens struktūros susidarymui kietėjimo metu ir jos pokyčiams veikiant aukštoms temperatūroms.

Submitted by Ronildo Prado (ronisp@ufscar.br) on 2017-08-23T12:31:55Z No. of bitstreams: 1 DissRGMS.pdf: 20398919 bytes, checksum: 000d866830c28ab133d11dda08ba6563 (MD5) / Approved for entry into archive by Ronildo Prado (ronisp@ufscar.br) on 2017-08-23T12:32:04Z (GMT) No. of bitstreams: 1 DissRGMS.pdf: 20398919 bytes, checksum: 000d866830c28ab133d11dda08ba6563 (MD5) / Approved for entry into archive by Ronildo Prado (ronisp@ufscar.br) on 2017-08-23T12:32:10Z (GMT) No. of bitstreams: 1 DissRGMS.pdf: 20398919 bytes, checksum: 000d866830c28ab133d11dda08ba6563 (MD5) / Made available in DSpace on 2017-08-23T12:32:16Z (GMT). No. of bitstreams: 1 DissRGMS.pdf: 20398919 bytes, checksum: 000d866830c28ab133d11dda08ba6563 (MD5) Previous issue date: 2015-12-23 / Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) / The growing demand of the steel industry for cheaper and more efficient production processes creates a necessity for new refractory materials. These requirements are written in terms of more robust concretes, with a longer life cycle, and ease of installation and maintenance. New materials that fulfill these criteria are the Mgo-based refractory castable. However, during curing and drying stages these materials have a critical magnesia hydration reaction that can lead to damage and cracks. The resonance measurement of elastic modulus technique is one of the techniques used to study the effects of magnesia hydration on the castables. As an alternative to this technique is proposed a digital image correlation (DIC) method to monitor the cracks network evolution of refractory castables during the curing stage. Samples (CDPs) of freshly molded castables were subjected to a controlled environment to cure and to dry and images were captured of CDPs with a high resolution digital camera. The DIC is an optical full-field displacement measurement technique. This method is based on the registration of digital images recorded in the undeformed and deformed configurations to measure displacements. A Correli-Q4 based software were developed to detect the cracks and measures their surface crack density and its average crack opening in the sample. The study of some variables such as the paint technique used in the samples (required for application of the CID technique) and the positioning of samples within the thermal chamber were required to evaluate the robustness of the software. As a result of that effort it was possible to compare the CID technique with resonance measurement of elastic modulus. The conclusion is that both detect simultaneously the cracks network beginning. The results claim that the DIC technique is promising because it promotes possibility of measure and compare parameters relative to the crack network (surface crack density and average crack opening) for different compositions of castables, temperatures and relative humidity maintained during curing. The analysis of these cracks network paraviii meters was consistent with the theory in the literature demonstrating the potential of the proposed method. / A crescente busca da indústria siderúrgica por processos de produção mais eficientes cria uma demanda por novos materiais refratários. Isto significa, concretos mais robustos, com ciclo de vida maior e, de maior facilidade de instalação e manutenção. Entre os novos materiais que preenchem estes requisitos estão os concretos aluminosos contendo magnésia. Entretanto, o processamento destes materiais possui algumas etapas críticas devido à reação de hidratação da magnésia que pode causar trincas. Dentre as técnicas já utilizadas para quantificar esse processo, destaca-se o monitoramento do módulo elástico por meio da técnica de ressonância de barra. Este trabalho visa gerar uma nova alternativa de avaliação da fissuração de concretos refratários durante a etapa de cura do processamento desses materiais com o auxílio da técnica de correlação de imagens digitais (CID). Corpos de prova (CDPs) de concreto recém-moldados foram submetidos a um processo controlado de cura e secagem e, durante este, foram capturadas imagens de uma das faces dos CDPs com uma câmera digital de alta resolução. A partir das imagens, o programa Correli-Q4 é utilizado para calcular os campos de deslocamentos de uma região de interesse. Por meio destes campos, um método desenvolvido detecta as trincas formadas e mede o seu comprimento total e a sua abertura média. A partir do método desenvolvido foi possível comparar a técnica de CID com a de ressonância de barra e conclui-se que ambas detectam a formação da rede de fissuras sendo, portanto, complementares. A técnica de CID se mostrou promissora, visto que foi possível medir e comparar diversos parâmetros da rede de fissuras (densidade superficial e abertura média das trincas) para diversas composições de concretos, diferentes temperaturas e umidades relativas mantidas durante a cura. A análise desses parâmetros da rede de fissuras foi coerente com a literatura demonstrando o potencial do método.

In steel manufacturing, temperature control is a critical parameter,as it is extremely important for the steel quality. In general,disposable sensors are regularly immersed in the melt for temperaturemeasurements. There are commercially available sensors for continuoustemperature measurements. In this study, a refractory cement is used for encapsulation andcarrier of a resistive temperature detector, for continuoustemperature measurements in molten steel. This cement is normallyused for manufacturing of steel melt crucibles. The work in thisstudy is mostly experimental and consist of characterization of thecement and development of the sensor. The characterization includesthe mechanical properties, the thermal shock resistance, the steelmelt resistance and obtainable surface roughness, for differentpowder fractions, water-to-cement ratio, firings and mixing method.Process developments were also done for the manufacturing of thesensor element and its carrier system. The end goal for continuous temperature measurement in molten steelfor more than 60 minutes was not reached. However, functional sensorswere developed where temperatures up to 1000 °C were measured duringcalibrations, and the cement was well characterized. This work has been carried out within the Strategic innovationprogram "Smartare Elektroniksystem", a joint investment of Vinnova,Formas and Energimyndigheten.

This thesis deals with the problem of no-cement corundum refractory castables. In the theoretical part, it focuses on NCC refractory and its use, production technology and input raw materials. The second part of the theoretical work deals with MgAl2O4 spinel. The practical part of the thesis then continues in the topic and focuses on cement-free refractory concrete and the influence of MgO content on their properties.