Adição de subprodutos da cinza da casca de café (coffea canephora) em massa cerâmica para porcelanato

To produce porcelain tiles fluxing agents are used in order to obtain a liquid phase during firing. This liquid phase fills the pores decreasing porosity, water absorption and contributes to material densification. In the porcelain tiles industry, feldspar is the main flux material used, with quantities ranging between 35 and 50%. Studies focus on the discovery of materials with flux characteristics that can reduce the consumption of feldspar by porcelain tiles industry. In this context, the coffee husk ashes, a residue obtained when coffee husks are burned to produce heat for the dryers during the processing of the green fruit, have as main chemical constituents potassium, calcium and magnesium, giving them characteristics of fluxing material. Brazil is the largest coffee producer in the world and is responsible for over 30% of the world s production. In this work a physical treatment of coffee husk ash was carried out in order to eliminate the organic matter and, after this, two by-products were obtained: residual wastes R1 and R2. Both residues were added separately as single fluxes and also in association with feldspar in mixtures with raw materials collected in a porcelain industry located in Dias d Ávila-Ba. The addition of these residues aimed to contribute to the reduction of the consumption of feldspar in the production of porcelain tiles. Specimens were produced with dimensions of 60 mm x 20 mm x 6 mm in an uniaxial die with compacting pressure of 45 MPa. The samples were heated to a temperature of 1200 °C, for 8 minutes. Tests were performed to characterize the raw materials by XRF, XRD, particle size analysis, DTA and TGA and, additionally, the results of the physical properties of water absorption, apparent porosity, linear shrinkage, density, dilatometry, flexural strength and SEM of sintered body were analyzed. Additions of less than 8% of the residue R1 contributed to the decrease of porosity, but the mechanical strength of the samples was not satisfactory. Additions of 5% the R2 residue contributed significantly to decrease the water absorption and apparent porosity, and also to increase the mechanical strength. Samples with addition of feldspar associated with the R2 residue, in proportions of 6.7% of R2 and 6.7% of feldspar, led to results of water absorption of 0.12% and mechanical strength of 46 MPa, having parameters normalized to the manufacture of porcelain stoneware tiles

Avaliação da incorporação combinada dos resíduos de cascalho de perfuração de poço de petróleo e de polimento do porcelanato em cerâmica vermelha

Among the industries, those that produce ceramic porcelain for use in construction industry and oil, during the exploration and production period, play an important role in the production of waste. Much research has been carried out both by academia and the productive sector, sometimes reintroducing them in the same production line that generated them, sometimes in areas unrelated to their generation, as in the production of concrete and mortar for the construction, for example, but each one in an isolated way. In this research, the aim is to study the combined incorporation of the waste drill cuttings of oil well and the residue of the polishing of porcelain, generated in the final stage of finishing of this product in a clay matrix, for the production of red pottery, specifically bricks, ceramic blocks and tiles. The clay comes from the municipality of São Gonçalo, RN, the drilling waste is from the Natal basin, in Rio Grande do Norte, and the residue of the polishing proceeds from a ceramic porcelain of the State of Paraíba. For this purpose, we used a mixture of a plastic clay with a non-plastic, in a ratio of 50% each, settling formulations with the addition of these two residues in this clay matrix. In the formulations, both residues were incorporated with a minimum percentage of 2.5% and maximum of 12.5%, varying from 2.5% each, in each formulation, which the sum of the waste be no more than 15%. It should be noted that the residue of the polishing of ceramic porcelain is a IIa class (not inert). The materials were characterized by XRF, XRD, TG, DTA, laser granulometry and the plasticity index. The technological properties of water absorption, apparent porosity, linear shrinkage of burning, flexural tensile strength and bulk density were evaluated after the sintering of the pieces to 850 °C, 950 °C and 1050 °C, with a burning time of 3 hr, 3 hr and 30 minutes, and 3 hr and 50 minutes, respectively, with a heating rate of 10 °C/minute, for all formulations and landing of 30 minutes. To better understand the influence of each residue and temperature on the evaluated properties, we used the factorial planning and its surfaces of response for the interpretation of the results. It was found that the temperature has no statistical significance at a 95% of reliability level in flexural tensile strength and that it decreases the water absorption and the porosity, but increases the shrinkage and the bulk density. The results showed the feasibility of the desired incorporation, but adjusting the temperature to each product and formulation, and that the temperatures of 850 °C and 950 °C were the one that responded to the largest number of formulations

Aproveitamento de resíduo de beneficiamento do caulim na produção de porcelanato cerâmico

Nowadays, industries from all sectors have great concerns over the disposition of the residues generated along the productive process. This is not different in the mineral sector, as this generates great volumes of residues. It was verified that the kaolin improvement industry generates great volumes of residue basically constituted of kaolinite, muscovite mica and quartz, which are basic constitution elements to formularisations of ceramics masses to the production of covering of stoneware tiles type. This happens because the methodology applied to the improvement process is still very rudimentary, what causes a very low yield, only ¼ from all the material volume that enters the improvement process, in the end, is marketable. The disposal of this residue, in a general way, causes a very big negative environmental impact, what has justified the researches efforts aiming to find a rational solution to this problem. In this way, the intention of this present work is the utilization of this residue in the manufacture of products to high quality ceramics covering, stoneware tiles in an industrial scale. For this purpose, the influence of the addition of the residue to a standard ceramics mass used by a ceramics sector company, already established in the market, with the intention of verifying the possibility of use of this residue as the mass complementary raw material and even the possible partial or total substitution of one of the components of the mass for the raw material in evidence will be studied. To the accomplishment of this work, the kaolin improvement residue generated by an industry of exploitation and improvement of kaolin, located in the region of Equador-RN, in the levels 1,2,4,8, 16 and 32% will be added to the standard mass already used for the production of stoneware tiles. The raw materials used, kaolin residue and the standard mass, were characterized through DRX, FRX, DTA, TGA and dilatometry. After the sintering of the bodies of test, tests of water absorption, apparent porosity, post burning linear retraction, apparent specific mass and flexural strength (3 point bending) were realized to determinate the technological properties of these materials. The results show the studied residue can be considered raw material of great potential to the industry of floor and ceramics covering of the stoneware tiles type

Sinterização de matrizes cerâmicas à base de alumina reforçadas por carbetos a partir de precursores poliméricos

Ceramic composites produced with polymerics precursors have been studied for many years, due to the facility of obtaining a complex shape, at low temperature and reduces cost. The main objective of this work is to study the process of sintering of composites of ceramic base consisting of Al2O3 and silicates, reinforced for NbC, through the technique of processing AFCOP, as well as the influence of the addition of LZSA, ICZ and Al as materials infiltration in the physical and mechanical properties of the ceramic composite. Were produced ceramic matrix composites based SiCxOy e Al2O3 reinforced with NbC, by hidrosilylation reaction between D4Vi and D1107 mixtured with Al2O3 as inert filler, Nb and Al as reactive filler. The specimens produced were pyrolised at 1200, 1250 and 1400°C and infiltred with Al, ICZ and LZSA, respectively. Density, porosity, flexural mechanical strength and fracture surface by scanning electron microscopy were evaluated. The microstructure of the composites was investigated by X-ray diffraction to identify the presence of crystalline phases. The composites presented apparent porosity varying of 31 up to 49% and mechanical flexural strength of 14 up to 34 MPa. The infiltration process improviment of the densification and reduction of the porosity, as well as increased the values of mechanical flexural strength. The obtained phases had been identified as being Al3Nb, NbSi2, Nb5S3, Nb3Si and NbC. The samples that were submitted the infiltration process presented a layer next surface with reduced pores number in relation to the total volume

Influência da adição de rejeitos cerâmicos nas propriedades de cerâmica vermelha da região do Recôncavo Baiano

The study of the physical and mechanic properties is an analysis of unquestioned importance on the production of the ceramic materials. In the region of the Recôncavo Baiano, there are ceramic and small brick factories, that still use rudimentary techniques, where the necessity of characterization of raw materials is denounced by the quality of the final product. The present work has for objective to study the behavior of the clay proceeding from the region of the Recôncavo, between the cities of Candeias and Camaçari/Ba, with addition of 5, 10 and 15% by weight of brick scraps, trying to optimize the physic and mechanical properties of the final product, aiming a better possibility of being manufactured, mechanic resistance, low linear retraction and water absorption. The brick scraps and the clay were characterized by FRX, DRX, TG, ATD and the granulometric analysis. Samples for testing where prepared by uniaxial pressing at 25Mpa, in 60x20x5mm size. The evaluated technological properties were: linear retraction, water absorption, apparent porosity and flexural strength. The samples were burned in electric oven in the temperatures of 850º, 950º and 1050ºC and compared its mechanical properties and the gresification. With addition of 15% by weight of brick scraps and burning at 900º-1000ºC the samples showed properties superior to that clay

Aproveitamento de resíduo de caulim em cerâmica branca

The world market of Kaolin has been growing as new investments for better quality of materials have been applied. This market produces amounts of dross that are put in the environment in a wrong way, causing damages to it. Trying to reduce these damages, researches have been done in an attempt to use kaolin dross in ceramic. The disposal of kaolin dross in the environment by the industries of the states of Rio Grande do Norte and Paraiba have great impact in society. Usually this dross is disposed clandestinely in places like roads, river banks and lands of small cities. The present work shows the characteristics of the kaolin produced by the mining company in Junco do Seridó, Paraiba state, western Seridó, 300 km from Natal, in the border of both states. After that, researches were done to study its physical and the chemistry characteristics, trying to see if it can be used in white ceramic. The samples got were bolted in fabric of 325# . The technological characteristics tried to use it as a product in white ceramic. For that, it was made a haracterization of the subject matter through enlargement analyses, ATG and ATD, elaborating three formulations that were burned in four different temperatures, 1175, 1200, 1250 and 1300 degrees centigrade up to 30 minutes. After the burning, the subjects were submitted to water absorbing tests, linear retreating, apparent porosity, apparent specific mass, resistance to flexibility and MEV. For one of the mixtures it was obtained demanded properties for a semi porous material

Estudo do efeito da substituição de caulim por resíduo de caulim na fabricação de cerâmica de revestimento

Companies involved in kaolin mining and treatment represent an important area of industrial development in Brazil, significantly contribution to the worldwide production of such mineral. As a result, large volumes of kaolin residue are constantly generated and abandoned in the environment, negatively contributing to its preservation. In this scenario, the objective of the present study was to characterize the residue generated from kaolin mining as well as to assess its potential use as raw material for the production of ceramic tiles. Ceramic mixtures were prepared from raw materials characterized by X-ray fluorescence, X-ray diffraction, particle size analysis and thermal analysis. Three compositions were prepared using kaolin residue contents of 10%, 20% and 30%. Samples were uniaxially pressed, fired at 1200ºC and characterized aiming at establishing their mineralogical composition, water absorption, apparent porosity, specific mass, linear retraction and modulus of rupture. The results showed that the residue basically consisted of kaolinite and successfully replaced raw kaolin in the preparation of ceramic title formulations without significantly affecting the properties of the fired material

Utilização de resíduos de rochas ornamentais na produção de cerâmica branca

The marble and granite waste come from the process of mining of those ornamental rocks for use in the building industry. Brazil is one of the largest producers of blocks or finished products of ornamental rocks, extracting about 5.2 tons / year. The largest national producers are the states of Espírito Santo, Minas Gerais and Bahia which account for 80% of the Brazilian production. However, the waste total amount during processing of these blocks reaches 40% of the total. The use of the waste produced by this industry in white ceramics could be a form of disposition, because these materials, are thrownasa mud directly at decantation ponds, wastelands or in rivers, without any treatment. The present work has as main purpose to study the influence that reject of the ornamental rocks on the physical and mechanical properties of white ceramics. X-Ray characterizations of raw materials by were performed X-Ray fluorescence, X-Ray diffraction, granulometric, thermogravimetric and thermodiferencial analysis, five formulations were made (0, 10, 20, 30, 40% in granite weight) wich were burned at three temperatures: 1100°C, 1150°C and 1200ºC with 60 minutes of sorling time. After sintering, the samples were submitted to different analyser absorption of water, linear retraction, apparent porosity, apparent specific mass, flexival stronght, and scanning were obtained microscopy. Compatible technological properties within the limits demanded for the production of porcelainized stoneware

Efeito da introdução de resíduo de cinza de forno cerâmico em massa para cerâmica estrutural

The red ceramics and structural ceramics, as they are known, include ceramic materials made by blocks of seals and structures, bricks, tiles, smail flagstones manacles, rustic floors and ornamental materials. Their fabrication uses raw material such as clay and clay sites, with some content of impurity. It has good durability and mechanical strength to compression, low cost, making it one of the mainly used materials in civil engineering. The incorporation of many industrial activities residue to ceramic products is a technological alternative for reducing the environmental impact caused by its carefree disposal. This incorporation can promote chemical change and inertness of metals from residue, by fixation in the glassy phase of ceramic during the burning stage. The main aim of this project is to study the technical feasibility of the addition of ceramic oven ash into formulations of mass for structural ceramics. In this project two kinds of clay (plastic and non-plastic) were used, as well as the ash from firewood used in the process of burning of structural ceramics. A group of experiments was outlined, which permitted the evaluation of the influence of the burning cycle in different temperatures of the ash content in formulations for ceramic blocks through technological properties, mechanical behavior and microstructure. Five samples were processed of each one of the masses of plastic and non-plastic clay without addition of ash and with addition of ash on the percentages of 10 % and 20 %, for temperatures of 850 °C, 950 °C, 1050 °C and 1150 °C, obtained through sinterization process. Among the studied compositions, the one which presented best performance was the mass of clay with 10 % of ash, at temperature of 1150 °C, with the smallest absorption of water, the smallest apparent porosity, specific apparent mass a bit over the others and greatest mechanical resistance to flexion. The composition made confirmed the technical feasibility of the use of ash in the mass for structural ceramics with maintenance of its necessary characteristics for its purposes

Estudo da formulação de massas cerâmicas provenientes da região do Seridó-RN para fabricação de telhas

This work has for objective study compared the characteristics and technological properties of ceramic bodies from the region of Seridó-RN. The region under study has identified 23 cities where they were 80 ceramics industries. To define the universe of search, there was a survey of pottery that are part of APL Seridó next to the IEL. The characteristics and operating conditions of ceramics industries of the region were identified through a socio-economic questionnaire applied locally, which addressed issues such as: profiles of companies, production process etc. The analysis of information collected from 24 companies identified in seven cities shows that the vast majority of industries is small, with family structure, obsolete equipment and labo, little qualified. Most of the pottery works with low technical knowledge, poor control of the production process and product technology. The raw collected were submitted to analysis of X ray diffraction, chemical composition, termical analysis, particle size distribution and plasticity. Then were produced five formulations and made by uniaxial pressure at 25 MPa for firing in temperatures varying from 850 to 1050 °C. The firing technological properties evaluated were: mass loss to fire, lineal shrinkage, apparent density, apparent porosity, water absorption and flexural strength (3 points). The results indicated that the raw materials from the region have significant similarities in the composition chemical and mineralogical. Furthermore, it indicates the possibility of the use of cycles of firing faster and efficient than the current, limited to some clay mass burning of certain conditions

Produção de grês porcelanato a partir de matérias-primas do Rio Grande do Norte e queima a gás natural

The State of Rio Grande do Norte, Brazil, possess major deposits of feldspar, clay, kaolin and talc, all raw materials used in the production of porcelainized stoneware tiles. Conversely, state industries manufacture only low added value red ceramics. Porcelainized stoneware tiles is one of the noblest ceramics, depicting low water absorption (typically below of 0,5%), in addition to excellent staining resistance and mechanical strength. The present work aims at investigating the potential of local raw materials for the production of porcelainized stoneware tiles. To that end, these materials were characterized by X-ray fluorescence, X-ray diffraction, particle size analysis, thermal gravimetric analysis and thermal differential analysis. Admixtures containing different compositions were prepared and fired at three temperatures, 1150, 1200 and 1250°C for 30 min. After firing, tests samples were characterized by water absorption tests, linear retraction, dilatometric analysis, apparent porosity, apparent specific mass, flexural strength, and microstructural analysis by XRD and SEM. The results revealed that ceramics with porcelainized stoneware tiles characteristics could be produced from raw materials originated in the State of Rio Grande do Norte

Estudo e caracterização de matérias-primas para o desenvolvimento de blocos sílico-calcários

The types of products manufactured calcium silicate blocks are very diversified in its characteristics. They include accessory bricks, blocks, products in dense material, with or without reinforcements of hardware, great units in cellular material, and thermal insulating products. The elements calcium silicate are of great use in the prefabricated construction, being formed for dense masses and hardened by autoclaving. This work has for objective develop formulations that make possible the obtaining of calcium silicate blocks with characteristics that correspond the specifications technical, in the State of the Rio Grande of the North, in finality of obtaining technical viability for use in the civil construction. The work studied the availability raw materials from convenient for the production of calcium silicate blocks, and the effect of variations of the productive process on the developed products. The studied raw materials were: the quartz sand from the city of São Gonçalo do Amarante/RN, and two lime, a hydrated lime and a pure lime from the city of Governador Dix-Sept Rosado/RN. The raw materials collected were submitted a testes to particle size distribution, fluorescence of X rays, diffraction of X rays. Then were produced 8 formulations and made body-of-test by uniaxial pressing at 36 MPa, and cured for 7 hours at about 18 kgf/cm2 pressing and temperature of approximately 180 °C. The cure technological properties evaluated were: lineal shrinkage, apparent density, apparent porosity, water absorption, modulus of rupture flexural (3 points), resistance compression, phase analysis (XRD) and micromorphological analysis (SEM). From the results presented the technological properties, was possible say that utilization of hydrated lime becomes more viable its utilization in mass limestone silica, for manufacture of calcium silicate blocks

Estudo do efeito do óxido de bário no comportamento de massas para porcelanato

In this work, it is proposed the study of the effect of barium oxide acting as synthetic flow in the behavior of masses for stoneware from the use of raw materials found in the deposits of minerals of the Rio Grande do Norte that it makes use of a great natural potential for the industrialization of the product. The porcelanato is a sophisticated product with excellent final properties being applied as ceramic coating in buildings of high standard of engineering. The raw materials selected for the development of the study had been two types of argilas, two types of feldspatos, dolomita, talco, barium carbonate and silica, being characterized by X-ray fluorescence, X-ray diffraction, granulometric analysis, dilatometric analysis and thermal analysis. Thus, it is intended to define four formulations using the cited raw materials that will be processed, conformed and sintered in the temperatures of 1150 °C, 1175 °C, 1200 °C, 1225 °C e 1250 °C. From the physical characterizations, chemical and morphologic of the formed formulations, the effect of barium oxide is determined in the physical and mechanical properties of the studied system carrying water absorption tests, linear retraction, apparent porosity, apparent specific mass, compacting curve, flexural strength and microstructural analysis by XRD and SEM. After analyzing the results, indicated that barium oxide acts as a flux of high temperature and as the ordering of structure, where the embedded glass phase has the nucleating effect phase potassium silico-aluminum reacting with free silica which together with the high content of potassium concentrated form a new crystalline phase called microcline. The masses studied with the addition of barium oxide present physical-mechanical properties highly satisfactory in reduced firing temperatures, which implies a saving in energy given off in the production and increased productivity

Produção de grês porcelanato a partir de matérias-primas do estado da Bahia

The State Bahia, Brazil, presents different geological sites it with a very expressive variety minerals. It is situated among the very important States which produces minerals for industries, such as pointed aggregate, ornamentals stones and ceramics raw materials. Nowadays only four companies producting ceramics tiles. Porcelainized stoneware tiles is one of the noblest ceramics, depicting low water absorption (typically below of 0,5%), in addition to excellent staining resistance and mechanical strength. The present work aims at investigating the potential of local raw materials for the production of porcelainized stoneware tiles. For this purpose, these materials were characterized by X-ray fluorescence, X-ray diffraction, particle size analysis, thermal gravimetric analysis, thermal differential analysis and dilatometric analysis. Admixtures containing different compositions were prepared and fired at four temperatures, 1100 ºC, 1150 ºC, 1200 ºC and 1250 ºC with isotherm for 60 minute and heathing rate of 5 oC/min. After firing the samples, they were characterized by water absorption tests, linear retraction, analysis, apparent porosity, apparent specific mass, flexural strength, and microstructural analysis by X-ray diffraction and scanning electron microscopy . The results revealed three ceramics with porcelainized stoneware tiles characteristics and porcelain tile will be produce from raw materials originated in the State of Bahia

Estudo do potencial de utilização do resíduo da extração de esmeraldas na fabricação de cerâmica de revestimento

Companies involved in emerald mining and treatment represent an important area of industrial development in Brazil, with significative contribution to the worldwide production of such mineral. As a result, large volumes of emerald waste are constantly generated and abandoned in the environment, negatively contributing to its preservation. By the other side the interest of the use of mining waste as additive in ceramic products has been growing from researchers in recent years. The ceramic industry is constantly seeking to the marked amplification for the sector and perfecting the quality of the products and to increase the variety of applications. The technology of obtaining of ceramic tiles that uses mining residues assists market niches little explored. In this scenario, the objective of the present study was to characterize the residue generated from emerald mining as well as to assess its potential use as raw material for the production of ceramic tiles. Ceramic mixtures were prepared from raw materials characterized by X-ray fluorescence, X-ray diffraction, particle size analysis and thermal analysis. Five compositions were prepared using emerald residue contents of 0%, 10%, 20%, 30% and 40%. Samples were uniaxially pressed, fired at 1000, 1100 and 1200ºC and characterized aiming at establishing their mineralogical composition, water absorption, apparent porosity, specific mass, linear retraction and modulus of rupture. The results shows that the emerald residue, basically consisted of 73% of (SiO2 + Al2O3) and 17,77% of (MgO + Na2O+ K2O) (that facilitates sintering), can be added to the ceramic tile materials with no detrimental effect on the properties of the sintered products