Erosion Resistance Of Refractories

The erosion resistance of refractories refers to the ability of refractories to resist the gradual erosion or damage caused by the chemical action of external media.

Refractories are inorganic non-metallic materials, mostly metal oxides and carbon containing materials, different materials have their own characteristics, so there are acid refractories, neutral refractories, alkaline refractories. Is not obvious under the condition of chemical reaction is due to the rise of temperature is becoming acute, such as 3 oxidation 2 aluminium and calcium oxide had very high refractoriness, will form the low melting point of two calcium aluminate, low melting point can be formed between silica and calcium oxide, calcium silicate, especially the low melting point of sulfur dioxide, sodium chloride and potassium element at 800 ℃ can generate molten liquid directly, In high temperature state, these low melting point components and refractory matrix components will produce high temperature chemical reaction, resulting in melting loss of materials, reduce the service life of refractory materials.

Therefore, in order to improve the service life of refractory materials, the first step of material selection is very important, to fully understand the main harmful ingredients in the customer's furnace charge, what is the nature of the material, and then determine the appropriate properties of refractory materials according to the actual situation. In general, when the charge is alkaline, alkaline or neutral refractory materials are selected. When the charge is acidic, neutral or acidic refractory materials are selected. Due to the complex composition of materials in the furnace, working temperature and furnace atmosphere should also be considered, sometimes it is necessary to carry out erosion test to finally determine the appropriate material.

In the actual operation of kiln, slag erosion is the main reason for the erosion of refractory materials. Lining refractories must contact materials, not only in the work but also in contact with all kinds of high temperature liquid slag and flue gas, the liquid phase composition and flue gas will be along the refractory porosity, micro cracks and grain boundary in the channel to the refractory internal penetration, and gradually enrichment of precipitation, causing refractory metamorphic layer, as a result of the metamorphic layer thermal expansion coefficient, It will cause a large number of defects and cracks in the material, in the case of alternating hot and cold, it will further cause the spalling of refractory materials, resulting in the reduction of the service life of the material.

There are three ways to improve the corrosion resistance of refractory materials. One is to select high quality and high purity materials to reduce the impurity content in the material and reduce the high-temperature chemical reaction between the material and the refractory components. 2 it is targeted, can add in refractory reacts with slag of high viscosity material composition, delay the slag erosion and penetration, the third is to add the appropriate material (carbon materials), improve the liquid slag infiltration Angle with refractory, infiltration of molten slag and material Angle to 90-180 degrees, make slag is hard to permeate;

refractory performance is closely related to the characteristics of material itself has, you cannot sell the cow and drink the milk, there is no more than a kind of material can the characteristics of both at the same time, any kind of refractories have their respective advantages and disadvantages, so all kinds of refractory materials has its own scope of application, when choosing refractory material should be carried out according to the actual conditions of use as a whole, Don't jump to conclusions. The demand for refractories in different industries is different, so the sales should also be carried out according to the specific needs of users.