The measurement of thermal expansion rate of blast furnace coke
1. Introduction
Coke is the most important fuel in the metallurgical industry. It has been widely used in integrated steelworks, iron ore smelting and ferroalloy electrolysis, blast furnaces and other high temperature smelting and heating. Solid fuel thermophysical properties are essential for the correct design, modeling and operation of the processes where solid fuels are used. Thermal expansion is one of an important thermophysical properties of coke and reflects the change of volume with temperature under the same pressure condition. It is closely related to the strength of coke, which is an important index for the comprehensive evaluation of coking quality.
2. The purpose of the test
The purpose of the experiment is to measure the thermal expansion rate of blast furnace coke. At the same time, it is also used to analyze the influence of the main factors on the thermal expansion of coke.
3. Apparatus and materials
The experiment used laboratory IW sample (8mm×12mm×25mm). The thermometer used in the experiment is a precision portable temperature recorder (measurement range -40~300℃). The sample furnace used in the experiment is a muffle furnace type, maximum temperature 1100℃.
4. The experimental procedure
1) The first step is to heat the oven to the specified temperature, and then place the prepared specimen into the overheated oven.
2) Keep the heating temperature constant, wait for the specimen to reach the specified temperature, and start the temperature recording. After 10 minutes, turn off the oven and record the temperature every two minutes until the sample temperature is lower than 100℃.
3) After cooling the specimens to room temperature, weigh the specimens respectively at this temperature.
4) The apparent thermal expansion rate of the specimens is calculated according to the relevant formula.
5. Results and Discussion
The experiment was performed in two heating stages. At the first stage, the sample was heated to 650℃, when the thermal expansion rate of the sample was 0.833%. Next, the sample was heated to 1100℃, when the thermal expansion rate was 1.04%.
To analyze the effects of temperature and temperature change on the thermal expansion rate of the sample, we performed a further analysis of the experimental data. The results of this analysis showed that as the temperature increased, the thermal expansion rate increased. The higher the temperature change rate, the greater the thermal expansion rate. This indicates that temperature and temperature change have a significant impact on the thermal expansion rate of the sample.
The analysis suggests that the thermal expansion rate of the sample is dependent on the temperature, and the rate of change of temperature is a primary factor. Therefore, when designing an industrial process involving the use of cokes, temperature control must be taken into account in order to achieve the desired expansion rate of the cokes.
6. Conclusion
In this experiment, the thermal expansion rate of blast furnace coke is measured. The results show that temperature and temperature change have a significant impact on the thermal expansion rate of the sample. It is important to consider temperature control when designing an industrial process involving the use of cokes.
