CEN/TC 187/WG 1 - Dense shaped refractory products

This document specifies three methods for the determination of the bulk density of granular refractory materials (grain density) having a grain size larger than 2 mm:
—    Method 1: mercury method with vacuum;
—    Method 2: arrested water absorption method;
—    Method 3: vacuum method with spin dryer option according to ISO 5017.
Method 1 is intended as the reference method.
NOTE       Depending on the nature of the material tested, the three methods can give different results. Any statement of the value of a bulk density can therefore be accompanied by an indication of the method used or to be used in case of dispute.
The same method can be used for the determination of the volume of the sample, for selecting and preparing the sample, for calculating the bulk density and for presenting the test report.

This document specifies three methods for the determination of the permanent change in dimensions on heating of dense shaped refractory products.
NOTE   The methods can be applied to materials sensitive to oxidation. However, some of these materials can be affected during the test in such a way as to make the measurement of the dimensional changes impossible to carry out to the required accuracy.

This Part of EN 993 specifies a method for the determination of the modulus of rupture of dense and insulating shaped refractory products at ambient temperature, under conditions of a constant rate of increase of stress.

This document specifies a method of determination of the cold crushing strength of dense shaped refractory products.

This document specifies a method for the determination of the bulk density, apparent porosity and true porosity of dense shaped refractory products.
NOTE   For shaped insulating refractory products, the bulk density and true porosity are determined in accordance with EN 1094-4.

ISO 10081-4:2014 specifies the classification and designation of dense shaped refractory products of special composition including oxide products, oxide and non-oxide products, non-oxide silicon carbide or carbon-based products, and further special products which are only designated but not classified, for example non-oxide products, such as boride, nitride or further combinations of the series given above.

This part of ISO 8894 describes the hot-wire methods (“cross-array” and “resistance thermometer”) for the determination of the thermal conductivity of non-carbonaceous, dielectric refractory products and materials.
This methods are applicable to dense and insulating refractories (shaped products, refractory castables, plastic refractories, ramming mixes, powdered or granular materials) with thermal conductivity values less than 1,5 W/m×K (“cross-array”) and less than 15 W/m×K (“resistance thermometer”) and thermal diffusivity values less than 5 x 10-6 m2/s.

ISO 1893:2007 specifies a method for determining the deformation of dense and insulating shaped refractory products, when subjected to a constant load under conditions of progressively rising temperature (or refractoriness under load), by a differential method. The test may be carried out up to a maximum temperature of 1700 °C.

ISO 16282:2007 specifies a method intended primarily for the determination of the abrasion resistance of shaped refractory materials at ambient temperature. It can also be used for unshaped refractory materials. It provides an indication of the suitability of the material for service in abrasive or erosive conditions.

This European Standard describes two alternative methods for determining the resistance to thermal shock of dense shaped refractory materials by an air quenching method, which proved to give the most reliable results when compared with the behaviour of refractories in furnace linings.
Method B can also be applied to unshaped refractory materials.

ISO 12680-1:2005 specifies a method for determining the dynamic Young's modulus of rectangular cross-section bars and circular cross-section specimens of refractories by impulse excitation of vibration. The dynamic Young's modulus is determined using the resonant frequency of the specimen in its flexural mode of vibration.

This document describes a hot-wire (parallel) method for the determination of thermal conductivity of refractory products and materials.  It is applicable to dense and insulating shaped products and to powdered or granular materials (see 6.2), for thermal conductivities of less than 25 W/m.K.  The limits are imposed by the thermal diffusivity of the test material and therefore by the dimensions of the test pieces; higher thermal conductivities can be measured if larger pieces are used.  Electrically conducting materials cannot be measured.
NOTE 1   The thermal conductivity of products with a hydraulic or chemical bond can be affected by the appreciable amount of water that is retained after hardening or setting and is released on firing. These materials may therefore require pre-treatment; the nature and extent of such pre-treatment and the period for which the test piece is held at the measurement temperature as a preliminary to carrying out the test, are details that are outside the scope of this standard and should be agreed between the parties concerned.
NOTE 2   In general it is difficult to make measurements on anisotropic materials and the use of this method for such materials should also be agreed between the parties concerned.

ISO 10081-2:2003 specifies the classification and designation of dense shaped basic refractory products with or without antioxidant additives. Products containing 7 % or more residual carbon after coking are excluded from this classification. The classification is applicable to dense shaped products with or without metal plates and reinforcement.

ISO 10081-3:2003 specifies the classification and designation of dense shaped basic refractory products containing 7 % or more but less than 50 % residual carbon after coking. It is applicable to products with or without antioxidant additives, with or without metal plates and reinforcement.

ISO 10081-1:2003 specifies the classification and designation of dense shaped refractory products of the alumina-silica series, with the following exceptions: products containing more than 5 % of any metallic oxide other than alumina, silica, iron oxide; and products containing more than 1 % carbon, carbides, nitrides, oxynitrides or any associated materials.

This European Standard describes a method for determining the thermal expansion of dense shaped refractory products under rising temperature by a differential method.
NOTE   The test can be carried out up to a maximum temperature of 1 700 °C.

In clause 5.2 to change the required accuracy of the balance used from '+/- 0,1 g' to '+/- 0,001 g'.

This European Standard specifies a method for the determination of the modulus of rupture of dense and insulating shaped refractory products at elevated temperatures, under conditions of a constant rate of increase of stress. A method for determination of the same property at ambient temperature is given in EN 993-6. Note: The method relates primarily to fired refractories. If it is to be applied to chemically bonded or tar-bonded bricks, the bricks will usually require some form of preliminary heat treatment.

This European Standard specifies the determination of the bulk density of granular refractory materials (grain bulk density) having a grain size greater than 2 mm, by the mercury method with vacuum.

This European standard specifies methods of test for refractory products based on oxides and containing carbon. The carbon may be added in an elemental form such as graphite, or as carbonaceous materials such as pitch, tar or resin.

This European Standard specifies a method for determining creep in compression of dense and insulating shaped refractory products, creep being the deformation of a refractory product subjected to a constant load under isothermal conditions.

This European Standard specifies a method for determining the pyrometric cone equivalent (refractoriness) for refractory materials including shaped and unshaped products. Its useful range of application depends on the availability of suitable pyrometric reference cones. In the temperature range from 1500 °C to 1800 °C, the pyrometric reference cones specified in EN 993-13 are suitable. As pyrometric reference cones are primarily manufactured for estimating the effect of temperature on siliceous, low alumina fireclay and fireclay products, the results on materials other than these may not be as precise.

This part of EN 993 specifies a method for determining the resistance of dense shaped refractory products to attack by sulphuric acid. NOTE: Sulphuric acid is used since it gives results which are typical of the results of exposing refractory materials to many acids (other than hydrofluoric acid).

This European standard specifies a method for the measurement of the permeability to gases of dense shaped refractory products.

This part of EN 993    specifies the characteristics of a standard series of pyrometric reference cones, which are used for determining the pyrometric cone equivalent (refractoriness) of refractory materials, over the temperature range 1500 to 1800°C.  The pyrometric reference cones specified are  suitable for use in the procedure described in EN 993-12, excluding determination of 1500 and 1800°C.

This part of EN 993    specifies a method for measuring the true density of refractory products and materials

This European standard specifies a method based on water absorption with vacuum for the determination of the bulk density of granular refractory materials (grain density) having a grain size larger than 2 mm. NOTE: This method is proposed as an alternative to the method based on mercury displacement with vacuum described in EN 993-17 which is to be used as the referee method because of its reproducibility. However, mercury is known to be a hazardous substance and the method in this EN is recommended for all routine purposes.

This European standard describes three methods for the determination of the permanent change in dimensions on heating of dense shaped refractory products. Note: The method can be applied to materials sensitive to oxidation. However, some of these materials can be affected during the test in such a way as to make the measurement of the dimensional changes impossible to carry out to the required accuracy.

This European standard specifies a method of determination of the cold crushing strength of dense shaped refractory products.

This part of EN 993    specifies a method for the determination of the bulk density, apparent porosity and true porosity of dense shaped refractory products. Note: For shaped insulating refractory products, the bulk density and true porosity are determined in accordance with EN 1094-4.

This part of EN 993 specifies a method for the determination of the modulus of rupture of dense and insulating shaped refractory products at ambient temperature, under conditions of a constant rate of increase of stress.  The method relates primarily to shaped and fired refractories.  If it is to be applied to chemically bonded or tar-bonded bricks, they will usually require some form of preliminary heat treatment.

This part of EN 12475 establishes the classification and designation of dense shaped refractory products of special composition of the following series:  a) oxide based products:  alumina-chromic oxide; alumina-chromic oxide-zirconia-silica; zirconia-silica; alumina-zirconia-silica;  b) oxide and non-oxide based products: alumina-carbon; alumina-silicon carbide-carbon; etc.

This part of EN 993 specifies a hot-wire (cross-array) method for the determination of thermal conductivity of refractory products and materials. It is applicable to dense and insulating shaped products and to powdered or granular materials (see 7.3), for thermal conductivities of less than 1,5 W/m.K.Electrically conducting materials cannot be measured. Note 1: The thermal conductivity of bonded bricks may be affected by the appreciable amount of water that is retained after hardening or setting and is released on firing.

This European Standard specifies a method for determining the deformation of dense and insulating shaped refractory products subjected to a constant load under conditions of progressively rising temperature, or 'refractoriness under load' by a differential method, with rising temperature. The test may be carried out up to a maximum temperature of 1700 °C.

This European Standard describes a method for the determination of the abrasion resistance of shaped refractory materials at ambient temperature. It provides an indication of its suitability for service in abrasive or erosive conditions.  It can also be used for unshaped refractory materials.

This part of EN 993 specifies a hot-wire (parallel) method for the determination of thermal conductivity of refractory products and materials. It is applicable to dense and insulating shaped products and to powdered or granular materials (see 7.2), for thermal conductivities of less than 25 W/m.K. The limits are imposed by the dimensions of the test pieces and higher thermal conductivities can be measured if larger pieces are used. Electrically conducting materials cannot be measured.

This part of EN 12475 specifies the classification and designation of dense shaped basic refractory products containing equal to or more than 7% and less t than 30% residual carbon after coking. It is applicable to products with or without antioxidant additives, with or without metal plates and reinforcement. Note 1: EN 12475-2 covers the classification of dense shaped basic products containing less than 7 % carbon. Note 2: All bricks can be encased in metal plate and be reinforced by means of an internal metal plate.

This part of prEN 12475 specifies the classification and designation of dense shaped basic refractory products with or without antioxidant additives. Products containing equal to or more than 7 % residual carbon after coking are excluded from this classification. The classification is applicable to dense shaped products with or without metal plates and reinforcement.

This part of EN 12475 specifies the classification and designation of dense shaped refractory products of the alumina-silica series, with the following exceptions: products containing more than 5% of any metallic oxide other than alumina, silica, iron oxide; products containing more than 1% carbon, carbides, nitrides, oxynitrides or any associated materials?

This Technical Specification specifies two alternative methods for determining the resistance to thermal shock of dense shaped refractory materials by the air quenching method which proved to give the most reliable results as compared with the behaviour of the refractories placed in furnace linings. Method B can be applied to unshaped refractory materials too.

This European Prestandard specifies the method for determining the resistance to thermal shock of dense shaped refractory materials by the air quenching method which proved to give the most reliable resuts as compared with the behaviour of the refractories placed in furnace linings.