Determination of the chemical composition of inorganic samples, carried out predominantly by the X-ray fluorescence technique, which can also be combined with other methodologies, such as atomic absorption, flame photometry and volumetry. In the most conventional routine, the levels are determined, with a detection limit of 100 ppm, of ten chemical elements in the form of oxides (SiO2, Al2O3, Fe2O3, TiO2, CaO, MgO, Na2O, K2O, MnO e P2O5), in addition to the loss on ignition at 1000oC (P.F.). The routine can be extended and/or adapted to detect other elements, such as heavy metals (lead, cadmium and others provided for in the RoHS standard), boron (in minerals and vitreous materials), radioactive elements (thorium and uranium), among others.
Qualitative identification of the crystalline phases present in samples using the X-ray diffraction technique. Through a combination of analytical techniques (stoichiometry, RIR-Rietveld, etc.), the results can be presented quantitatively, depending on the nature of the samples. Particularly useful for the identification and quantification of minerals present in samples of raw materials, as well as for the identification of crystalline phases present in synthetic compounds and products that exhibit crystallinity.
Microstructural analyses through observation of samples using a scanning electron microscope, combined with spot microanalysis of chemical composition using energy dispersive spectrometry (EDS). It allows magnifications of up to 50,000x on samples and can be useful for analyzing specific manufacturing defects, characterizing the sizes and morphologies of mineral particles and crystalline phases, detecting contaminants in raw materials and products, among others.
Assessment of the area occupied by the surface of particles that constitute a unit of mass, usually expressed in m2/g. A quantificação da área superficial específica é realizada pelo método B.E.T., onde ocorre a adsorção de moléculas de nitrogênio na superfície das partículas das amostras. A técnica ainda permite a avaliação da porosidade e dos tamanhos dos poros presentes nas partículas, através das isotermas de adsorção e dessorção, permitindo a caracterização dos perfis de porosidade (microporos / mesoporos). Trata-se de uma medida importante, tendo em vista que todas as reações químicas se iniciam a partir da superfície. Dessa forma, se relaciona com a plasticidade de argilominerais, grau de moagem e tamanhos de partículas, reatividade durante a sinterização e processamento de reações químicas, dentre outras aplicações.
Detection of mass loss shown by samples during heating at high temperatures. A Analysis is conducted on a thermobalance, which monitors the weight of the sample during the heat treatment carried out, from room temperature to the maximum temperature of 1100oC, in an oven with controlled heating speed of up to 15oC/min. The results allow the identification of the temperature ranges in which the samples lose weight during heating and can also help in identifying dehydration, combustion, volatilization and other reactions that occur concomitantly with weight change.
Determination of the apparent viscosity of fluids, at controlled shear rates. A Analysis is performed in a Brookfield rotational viscometer under controlled stirring speeds. The results are useful in evaluating the fluidity of suspensions and emulsions.
Determination of the chemical composition of inorganic samples, carried out predominantly by the X-ray fluorescence technique, which can also be combined with other methodologies, such as atomic absorption, flame photometry and volumetry. In the most conventional routine, the levels are determined, with a detection limit of 100 ppm, of ten chemical elements in the form of oxides (SiO2, Al2O3, Fe2O3, TiO2, CaO, MgO, Na2O, K2O, MnO e P2O5), in addition to the loss on ignition at 1000oC (P.F.). The routine can be extended and/or adapted to detect other elements, such as heavy metals (lead, cadmium and others provided for in the RoHS standard), boron (in minerals and vitreous materials), radioactive elements (thorium and uranium), among others.
Qualitative identification of the crystalline phases present in samples using the X-ray diffraction technique. Through a combination of analytical techniques (stoichiometry, RIR-Rietveld, etc.), the results can be presented quantitatively, depending on the nature of the samples. Particularly useful for the identification and quantification of minerals present in samples of raw materials, as well as for the identification of crystalline phases present in synthetic compounds and products that exhibit crystallinity.
Microstructural analyses through observation of samples using a scanning electron microscope, combined with spot microanalysis of chemical composition using energy dispersive spectrometry (EDS). It allows magnifications of up to 50,000x on samples and can be useful for analyzing specific manufacturing defects, characterizing the sizes and morphologies of mineral particles and crystalline phases, detecting contaminants in raw materials and products, among others.
Microstructural analyses by observing samples using a benchtop optical microscope, with a digital interface for image capture. It allows magnifications of up to 250x on samples and can be useful for analyzing specific manufacturing defects, characterizing the sizes and morphologies of particles and particle clusters, among others.
Determination of particle size distribution curves or particle agglomerates using sieving and/or X-ray sedimentometry (Sedigraph) and/or dynamic light scattering (DLS) techniques. When evaluating particles or agglomerates, analyses They are carried out in a series of sieves with standardized openings, in accordance with specific standards. In the case of particles with sizes between 0.1 µm and 100 µm, the analyses are carried out by sedimentation, based on Sotokes’ Law, in a particle analyzer (Sedigraph) that operates with an X-ray beam. For the analysis of particles of nanometric dimensions, the analyses are conducted by light scattering (DLS), with the ability to detect particles with sizes between 1 nm and 10 µm. The analyses apply to minerals and compounds of different natures, involving applications in the ceramic, pharmaceutical, paint, polymer, etc. industries. They can be useful for adjusting grinding and micronization systems, among many other applications.
Assessment of the area occupied by the surface of particles that constitute a unit of mass, usually expressed in m2/g. A quantificação da área superficial específica é realizada pelo método B.E.T., onde ocorre a adsorção de moléculas de nitrogênio na superfície das partículas das amostras. A técnica ainda permite a avaliação da porosidade e dos tamanhos dos poros presentes nas partículas, através das isotermas de adsorção e dessorção, permitindo a caracterização dos perfis de porosidade (microporos / mesoporos). Trata-se de uma medida importante, tendo em vista que todas as reações químicas se iniciam a partir da superfície. Dessa forma, se relaciona com a plasticidade de argilominerais, grau de moagem e tamanhos de partículas, reatividade durante a sinterização e processamento de reações químicas, dentre outras aplicações.
Identification of reactions that occur with the release or absorption of energy during the heat treatment of samples. The analyses can be carried out from room temperature to a maximum temperature of 1100oC, in an oven with controlled heating speed of up to 15oC/min. Endothermic and exothermic reactions are identified by temperature range and, eventually, the heat of reaction can be quantified. The technique can be used to identify the aforementioned reactions, control thermal processes and assist in identifying compounds or minerals present, as many have known reactions during heating.
Detection of mass loss shown by samples during heating at high temperatures. A analysis is conducted on a thermobalance, which monitors the weight of the sample during the heat treatment carried out, from room temperature to the maximum temperature of 1100oC, in an oven with controlled heating speed of up to 15oC/min. The results allow the identification of the temperature ranges in which the samples lose weight during heating and can also help in identifying dehydration, combustion, volatilization and other reactions that occur concomitantly with weight change.
Determination of the thermal expansion of solids and their respective thermal expansion coefficients (α) at temperature ranges. The analyses are carried out using contact thermodilatometers, responsible for controlled heating of the samples (at heating rates of up to 5oC/min, from room temperature to a maximum of 1100oC). In addition to dilatometric curves and thermal expansion coefficients, the analyses allow the identification of glass transition and softening temperatures in vitreous materials and can be used to predict the development of stresses caused by differences in thermal expansion between materials of different natures.
Assessment of deformations that occur during heat treatment at high temperatures of materials subjected to bending stress. Monitoring is carried out by a lens system with a resolution of 0.2 µm on specimens measuring 85 x 5 x 5 mm3. As análises podem ser conduzidas para obter resultados de alta precisão em ensaios de resistência à flexão à quente, avaliações de deformações piroplásticas com os respectivos cálculos de índice de piroplasticidade (IP), testes de hidrodeformação (curvaturas motivadas pela aplicação de água na superfície de placas cerâmicas cruas) e análises de tensão de acoplamento entre camadas de diferentes coeficientes de dilatação térmica.
Numerical analysis indicative of color and color variation in the same sample or between samples. The evaluation is carried out using a reflectance spectrophotometer, which determines the visible light reflection curve, in addition to the chromatic coordinates L*, a*, b* and ΔE*. The tool is useful for quality control, as it eliminates the subjectivity of visual color analysis. Furthermore, it can assist in the interpretation of degradation phenomena, stain formation, etc., which occur with color changes after various procedures (exposure to radiation, contact with water, chemicals or other staining agents).
Measurement of the cation exchange capacity of clays, kaolins, bentonites and soils in general. The test is carried out using the methylene blue adsorption method. This is a titration, under controlled conditions, where the saturation point is determined, in which the cations of the methylene blue molecule replace the exchangeable cations present in clay minerals. The analysis, as it relates to the surface area of the particles and the nature of the clay minerals, establishes an important correlation with the plasticity and ease of deflocculation of clays. Furthermore, it can be used to assess soil fertility.
The real density, also called absolute density or real specific mass, corresponds to the ratio between the mass and the volume occupied by the solids. Determined using a helium gas pycnometer, the equipment is capable of accurately determining the volume occupied by the solid fraction of powders or shaped samples, completely excluding the volume occupied by open pores (empty spaces) from this assessment. Therefore, the analysis allows the density of minerals and other compounds to be identified. In the case of products obtained after chemical reactions or sintering, the technique makes it possible to evaluate the density of the products obtained, bearing in mind that this may be different from the density of the precursor raw materials.
Determination of pore size distribution curves, combined or not with the evaluation of the open porosity of the samples. The analyses are carried out using a mercury porosimeter, which determines the pore intrusion diameter. Considering that in porous materials, many properties are determined by the size and volume of the pores, the technique is very useful for interpreting phenomena of permeability, mechanical behavior, thermal conductivity, among others.
Assessment of the total concentration of soluble salts in clay samples and soils in general, through sample solubilization and a combination of analytical techniques, such as gravimetry, flame photometry and tritrimetry.
Determination of total carbonate concentration in mineral samples. The analyses are carried out by calcimetry, in a Bernard calcimeter, where the carbonate content is determined from the volume of CO2 released in the reaction between hydrochloric acid and the carbonates present in the sample. The analysis can be carried out on the sample as received or on particle size fractions, depending on the objectives of the tests. Identification of the presence and quantity of carbonates by calcimetry can be useful especially in cases where carbonates are considered contaminants of minerals.
Determination of the total concentration of carbon and sulfur in a specific analyzer for this purpose. The samples are heated to high temperatures and the carbon and sulfur present are released in the form of CO2 e SO2. Estes gases posteriormente são detectados por células de infravermelho, cujos sinais são utilizados para a quantificação dos elementos de interesse. As analyses They are useful for determining carbon and sulfur content in steels and metallic alloys, ceramic materials and other inorganic compounds. In the case of clays, the technique is useful for determining the concentration of organic matter, which influences phenomena such as black heart and rheological behavior in suspension.
Evaluation of the roughness profile of solid samples, indicating the average roughness (Ra) or other quantitative numerical parameters of interest. The equipment has a mechanical rod with a thin metal tip, which runs along a pre-determined profile of the sample surface at a constant speed. The vertical movements of the probe are used to evaluate the roughness profile of the samples. The technique is useful for evaluating the surface regularity of materials of different nature. In the case of ceramic tiles, it is related to slip resistance.
Quantification of the calorific value in solids and liquids. Calorific value indicates the amount of energy contained in a unit of mass, and is usually expressed in Kcal/g. A analysis It is carried out in a calorimetric bomb, with automatic oxygen injection and water circulation. The analyses, in the case of solid fuels, can also be combined with the determination of volatile material, ash content and fixed carbon content. It can be applied to fuels in general, biofuels, biomass, food and animal feed.
Determination of sample refractoriness. Analyses are carried out in comparison with reference pyrometric cones, which indicate the samples’ ability to withstand high temperatures without deforming or melting. The tests are carried out up to the limit temperature of 1600oC, in laboratory muffle furnaces. The results are useful for evaluating the potential of raw materials for application in the refractory sector and also allow the evaluation of the performance of products (refractory or not) when subjected to heat.
Determination of the apparent viscosity of fluids, at controlled shear rates. The analysis is carried out in a Brookfield rotational viscometer under controlled stirring speeds. The results are useful in evaluating the fluidity of suspensions and emulsions.
Analysis of the thixotropy index of fluids, through experiments at controlled shear rates and resting or agitation times. The analysis is carried out in a Brookfield rotational viscometer under controlled stirring speeds. The results can be useful for evaluating the effects of time on the fluidity of suspensions and emulsions.
Assessment of the ease of flow of powdery materials. Determined using the Hausner Index or free flow method in a funnel of standardized dimensions (volumetric fluidity). The analysis is indicated to evaluate the ease of transport and flow of powdery compounds (granulated or not). The determination of the Hausner index is accompanied by measurements of filling and packing density.
Assessment of the possibility of using minerals and, possibly, industrial waste as pozzolanic materials. Pozzolans can be successfully used to partially replace cements in various applications. The analyses are carried out through compression resistance tests, where the mechanical resistance of concrete obtained by replacing 25% of the total cement load with the material whose pozzolanic activity is desired is verified. The results inform the potential of the tested samples for application with pozzolanic purposes.
Determination of water absorption and apparent porosity of solids. The open pores of the samples are initially saturated with water in a standardized procedure. Water absorption is calculated by the percentage gain in mass of the sample after saturation of the pores with water, while apparent porosity is calculated using the Archimedes method. Saturation of open pores can be carried out with water or another fluid, by immersion at room temperature, by immersion in boiling water or in a vacuum chamber, depending on the standard considered. The results are used to interpret permeability phenomena, mechanical performance, thermal conductivity, etc.
Analysis of dimensional variations produced in test specimens by heat treatments at high temperatures. The analyses are carried out through dimensional evaluations of the samples before and after the established heat treatment, which can be carried out in laboratory ovens in order to reproduce the conditions of manufacture and/or use of the materials. The results are used to demonstrate the dimensional stability of the samples depending on the temperature and heating cycle practiced.
Assessment of the mechanical performance of materials, determined on a universal testing machine, in different configurations. Tests can be carried out to evaluate the resistance to flexion, compression or traction of materials of different natures, in accordance with the standards applied for each situation. The equipment monitors the deformations suffered by the samples depending on the applied stresses, allowing the determination of the elastic modulus, yield limit and rupture stress, among other parameters. The analyses are extremely useful for indicating the performance of materials against mechanical stress and used in engineering calculations for material specification. In the case of ceramic products, in addition to performance during use, they can be used to evaluate the performance of parts before sintering, indicating the ease of transport and handling of green parts.
Determination of the effects of firing temperature on water absorption (or apparent porosity) and firing shrinkage of ceramic bodies and raw materials. The analysis is carried out on test ceramic bodies made from the samples, which are fired at at least four different temperatures in laboratory ovens. The results of the analyses make it possible to evaluate the fusibility of the samples and their sensitivity to temperature variations, and can even guide the definition of the firing curves of ceramic materials.
Assessment of the plasticity index of clays or soils, related to the nature and proportion of clay minerals present in the samples. The analysis is carried out using a standardized procedure, where the plasticity index is determined through prior analysis of the liquidity limit (in a Casagrande apparatus) and the crumbling water. The plasticity index can be used to interpret the plasticity of clays, as well as to evaluate the drainage capacity of soils.
The black heart corresponds to a dark nucleus formed in the central portion of ceramic pieces, due to the presence of iron and the incomplete combustion of organic matter that accompanies some clays. The objective of the analysis is to evaluate the tendency for black heart formation in samples of clay and ceramic bodies. The analyses are carried out on pressed and burned specimens under severe conditions to enhance the formation of black hearts. This is a comparative analysis that can be used to evaluate the potential of raw materials for the ceramic industry and can eventually guide the development of dough formulations and the optimization of processing conditions.
Determination of the water stain formed under standardized conditions in engobes compositions or on ceramic tiles for coating. The analyses are carried out after immersing the samples in water for standardized periods. The color differences detected in the samples after the immersion procedure are evaluated using the colorimetric parameter ΔE*, determined using a reflection spectrophotometer. The results are useful for evaluating the performance of ceramic engobes compositions and are also considered as a quality parameter for ceramic tiles, in accordance with the ABNT NBR 15575:2013 standard – Residential Buildings – Performance.
Determination of the thermal conductivity coefficient (Kc) of solid materials at high temperatures. Analyses are carried out at at least three temperatures (between 400oC e 1000oC) by the calorimetric method, based on the procedures described by the ASTM C201 – 93 standard. The results allow evaluating the thermal insulation power of dense or insulating refractories, in addition to other materials used in the thermal insulation of industrial installations subjected to high temperatures.
Fusibility assessment of fluxing materials after burning at temperatures above 1200oC. The test is carried out using cones of standardized dimensions, conformed to the samples received. After burning at defined temperatures, the cones are evaluated for color, brightness and change in original shape, which is indirectly related to the viscosity of the liquid phases formed during burning. This is an analysis used to evaluate the fusibility and color of minerals such as feldspars, nephelines, basalts and granites, among others.
Assessment of the relationship between drying shrinkage and residual moisture of ceramic bodies and clays during the drying process. The test is carried out by monitoring the drying process of test specimens or industrial parts, through periodic assessments of drying shrinkage and humidity. The Bigot curve is useful for evaluating the sensitivity of masses and clays during the drying process. Likewise, it provides useful information for designing drying curves, establishing the critical moisture content in the samples, responsible for conditioning the drying speed of ceramic products.
Determination of permeability coefficients (K1e K2) in porous materials. The analyses are conducted in a permeameter, using the steady-state airflow method. In the equipment, an air flow is forced to pass through test bodies made with samples and their pressure values are monitored during this process. The results are useful for interpreting diverse phenomena associated with the porous structure of solid materials. In the case of ceramic products, it provides important information regarding the ease of releasing gases, such as water vapor during drying and other gases during sintering.
NBR 13.818. Anexo B
NBR 13.818. Anexo H
NBR 13.818. Anexo Q
NBR 13.818. Anexo E
NBR 13.818. Anexo A
NBR 13.818. Anexo S
NBR 13.818. Anexo C
NBR 13.818. Anexo L
NBR 13.818. Anexo N
NBR 13.818. Anexo J
NBR 13.818. Anexo F
NBR 13.818. Anexo V
NBR 13.818. Anexo D
NBR 13.818. Anexo D
NBR 13.818. Anexo G
ISO 10545
