One Question per Day: Methanol Technology Exchange Edition 20180526
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Learn from the advanced practices of the *Brothers section; there are prizes for correct answers – every response earns a reward, allowing us to grow and mature through these Q&A sessions. Short-answer question: What is the basis for determining the high or low ash fusion temperature? How to reduce the ash fusion point? We usually determine the ash fusion point based on the ratio of alkaline to acidic substances in coal. A higher ratio results in a lower ash fusion point ； A lower ratio results in a higher ash fusion point. Adding limestone CaCO3 to the raw coal increases the content of alkaline substances in the coal, raising the alkali-to-acid ratio and thus reducing the ash melting point.
There are many factors to consider when determining the ash fusion temperature; 1. Laboratory data is the most accurate. 2. Ash composition, the ratio of acidic to basic ash components; the lower this ratio, the lower the ash fusion point, and conversely, the higher this ratio, the higher the ash fusion point
We usually determine the ash fusion point based on the ratio of alkaline to acidic substances in coal. A higher ratio results in a lower ash fusion point ； A lower ratio results in a higher ash fusion point. Adding limestone CaCO3 to the raw coal increases the content of alkaline substances in the coal, raising the alkali-to-acid ratio and thus reducing the ash melting point.
To lower the ash fusion point, it is necessary to analyze the ash composition. Coal with a high calcium content also has a high ash melting point; in such cases, CaCO3 cannot be added, and silicates may need to be used instead.