CS259067B1 - The method of identifying the type and determining the content of oxlloid fusions in the inorganic materials - Google Patents

Abstract

The invention relates to a method for the identification and determination of oxide phases in inorganic materials by the thermoevolution method. The analyzed sample is gradually heated in a graphite crucible and the gaseous products of the reduction of oxide phases by carbon, i.e. carbon monoxide and carbon dioxide, are continuously detected depending on the temperature. Identification and determination of oxide phases by temperature-controlled reduction with detection of carbon monoxide is carried out in the temperature range of 600 to 1,400° C.

Description

The invention relates to a method for identifying the type and determining the content of oxidic phases in inorganic materials by the method of temperature-controlled high-temperature reduction of the oxidic phases in a sample by elemental carbon, producing carbon monoxide and carbon dioxide simultaneously. The present invention falls within the field of analytical chemistry.

The presence of oxygen in the form of various oxides significantly affects the properties of metallic materials, the amount and type of oxygen binding in the metals gives a basic indication of the quality of the metal. the production process, the behavior of the material in different environments and the origin and course of various phenomena and interactions. The same applies to a variety of non-metallic inorganic materials such as slags, silicates, enamels, pure oxides and the like. Knowledge of the amount and types of oxidic phases in a material is therefore often a critical condition in solving many technical problems.

The question of determination of quantities and types of oxidic phases in materials is currently solved by the so-called thermoevolution method based on the principle of gradual thermal reduction of oxidic phases by graphite in an inert atmosphere and on continuous detection of the resulting gaseous oxygen product in relation to the reduction temperature. From the temperature level at which the oxide is reduced, one can deduce its type, and from the amount of gaseous compound formed to its amount. This principle of determination has been implemented in several types of analyzers in recent years. The principle of said thermoevolution method and the conception of all the previous types of devices is based on the detection of oxygen in the form of carbon monoxide; provided that the only gaseous product of the high temperature reduction of the oxidic phases is carbon monoxide, and detection systems are commonly adapted to this assumption. However, research in this field found 259067

- 2 the above assumption reliably applicable only to the oxidic phase of the high temperature reduction of over 1 300 to 1 400 C, i.e. in particular alumina algo ^, silica Si0 _2, CaO, MgO, TiO ^ and some others. Study of high temperature reduction of a number of other types of oxides reacting with carbon in the temperature range of 500-100 ° C, ie copper oxide CuO, copper oxide Cu ^ O, tin oxide SnO ₂ , iron oxide FeO, chromium trioxide Cr ₂ 0y manganese oxide MnO and others, it has been proved by gas chromatography and quadrupole mass spectrometry that besides carbon monoxide, carbon dioxide is also an important reaction product. The weight ratio of the two oxides formed is dependent on the type of reduced oxide, sample matrix, temperature analysis program and other factors . In many cases, carbon dioxide is the dominant component of the reaction products.

It follows from the above finding that the current method of analyzing oxidic phases using existing types of equipment cannot reliably analyze various metallic and other inorganic materials, since the results of the analyzes are burdened by a major error of the method, often reaching tens of relative percentages. in any way.

This drawback removes the method of identifying the types and determining the oxidic phase content of inorganic materials by the temperature-controlled high temperature reduction of the oxidic phases in the sample by elemental carbon, which simultaneously produces carbon monoxide and carbon dioxide, which are detected according to the invention. It is based on the fact that the identification and determination are carried out during the gradual heating of the sample in the temperature range of 600 to 1400 ° C.

The method for identifying the type and determining the content of oxidic phases in the inorganic materials according to the invention makes it possible to reliably identify most of the real types of oxidic phases in metallic and other inorganic materials, and in particular to correctly determine their content. The proposed solution can be applied especially in the identification of oxidic phases in non-ferrous metals and alloys, in pure metal oxides and their mixtures, in products of oxidation and degradation of metals and the like.

Examples

Example 1

Study of high-temperature copper oxide reduction, theoretical oxygen content of 11.2%, by carbon gradual heating of the sample in the temperature range

600 DEG-1400 DEG C., it was found that the reduction was carried out at a temperature of 259067

- 3 rolls of about 1 050 to 1 200 ° C with simultaneous formation of carbon monoxide CO and CO ₂ in a volume ratio of about 2 and 1. The analysis of pure copper oxide Cu ₂ O has hitherto determined the oxygen content of 6.5%, ie 75% of total content. According to the invention, realized in the form of oxide column jodičným ^ 2 ° 5 * ^ P ^lay before shifting detector dioxide CO ^^ ^ OuSÍŠ carbon monoxide CO to carbon dioxide C0 ₂ value was determined OB- <fathom oxygen 11.4% .

Example 2

Study of high temperature chromium oxide reduction, theoretical oxygen content of 46%, by carbon gradual heating of the sample in the temperature range of 60u to 1400 ° C, it was found that the reduction takes place in the temperature range of about 920 to 1020 ° C. CO 2 in a volume ratio of about 1: 1. By analyzing the pure chromium trioxide CrO 2 to date, an oxygen content of about 22%, i.e. 46% of the total content, was determined. By the method of the invention, as in Example 1, the oxygen content was 46%.

Example 3

By phase analysis of the purity of metallurgical copper with a total content of 0.030% oxygen, it was found that the dominant oxide impurity is copper (I) oxide. Upon identification and determination to date, it has been found that 0.005% oxygen is bound in the form of CuOgO. By the process of the invention, as in Example 1, it was found that 0.027% oxygen, i.e. virtually all the oxygen in the material, is bound in the form of Cu ₂ O 3. The remaining oxygen was identified by the method of the invention in the form of tin oxide ShOg.

Claims (1)

SUBJECT OF THE INVENTION Method for identifying the type and determining the content of oxidic phases in inorganic materials by the method of temperature-controlled high-temperature reduction of the oxidic phases in a sample by elemental alkali which simultaneously produces carbon monoxide and carbon dioxide which are detected, characterized in temperature range of 600 to 1400 ° C.