What does the loss of fly ash mean?
In recent years, with the strengthening of environmental protection policies and the promotion of industrial waste resources reuse, fly ash, as a by-product of coal-fired power plants, has gradually attracted attention. Among them, the professional term "loss of fly ash" frequently appears in research and practice in the fields of building materials, environmental protection, etc. This article will analyze in detail the meaning, influencing factors and practical applications of fly ash loss based on the popular topics and hot contents of the entire network in the past 10 days.
1. Definition of fly ash loss
Loss on Ignition (LOI) refers to the percentage of mass loss when flying ash is burned at high temperatures (usually 950°C±25°C). The amount of burning mainly reflects the content of unburned carbon, organic matter and volatile matter in fly ash. This indicator is one of the important parameters for evaluating fly ash quality, and directly affects its application performance in building materials such as cement and concrete.
2. Factors influencing the loss of fly ash
According to recent hot discussions, the loss of fly ash is mainly affected by the following factors:
| Factors | Specific instructions |
|---|---|
| Coal-fired process | The low combustion efficiency of the boiler will lead to an increase in the unburned carbon content in fly ash and an increase in the burnout loss. |
| Coal species characteristics | Coal species with high ash or low calorie value are prone to produce high fever loss of fly ash. |
| Collect method | The amount of fly ash collected by electrostatic dust collectors is usually lower than that collected by mechanical dust collectors. |
| Storage conditions | Long-term exposure to humid environments may cause fly ash to absorb moisture and increase burn loss. |
3. Standard requirements for fly ash loss
According to national standards and industry specifications, the limit of fly ash loss varies depending on the application scenario. The following are the relevant criteria mentioned in recent discussions:
| Application areas | Burn loss limit (%) | Reference standards |
|---|---|---|
| Cement mix | ≤8.0 | GB/T 1596-2017 |
| Concrete blending (Class I) | ≤5.0 | GB/T 1596-2017 |
| Concrete blending (grade II) | ≤8.0 | GB/T 1596-2017 |
| Roadbed filling | ≤15.0 | JTG/T F20-2015 |
4. Treatment and utilization of high-frequency loss of fly ash
Among the recent environmental protection hotspots, the resource utilization of high-frequency loss of fly ash has attracted much attention. Here are some common methods of handling:
1.Carbon sorting technology: Separate unburned carbon by flotation, electric selection and other methods to reduce the burnout and recover carbon resources.
2.Calcination treatment: Secondary calcination under controlled conditions to completely remove organic matter and volatile matter.
3.Modification application: Improve its performance through chemical activation or physical grinding, and is used for non-structural building materials or soil improvement.
5. Methods for detecting fly ash loss
According to GB/T 176-2017 "Cement Chemical Analysis Method", the detection steps for fly ash loss are as follows:
1. Take about 1 g of fly ash sample and place it in a crucible with constant weight.
2. Put it in a muffle furnace, increase it from low temperature to 950℃±25℃, and burn for 1 hour.
3. Remove and place in a dryer and cool to room temperature and weigh.
4. Calculation formula: ignition loss (%) = (mass before burning - mass after burning)/mass before burning × 100.
6. Future trends in research on fly ash loss
Based on recent academic hotspots, future research may focus on the following directions:
1.Online testing technology: Develop fast and accurate real-time monitoring equipment for burnout loss.
2.Low-carbon combustion optimization: Optimize boiler combustion parameters through artificial intelligence to reduce burn loss from the source.
3.High-value utilization: Explore the application of high-fire loss fly ash in the fields of adsorption materials, catalyst support, etc.
To sum up, the loss of fly ash is a key indicator for measuring its quality, which directly affects the effectiveness of resource utilization. With the advancement of technology and the improvement of environmental protection requirements, through process improvement and comprehensive utilization, the "turning waste into treasure" of high-fire fly ash will become an important topic in green development.
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