Temu 5 Tek Btbr Uji Kimia dan Geokimia (Part 1)

Summary

In this lecture for mining engineering students, the instructor discusses the chemical and biochemical testing of coal, emphasizing the importance of visual analysis for assessing coal quality. Key topics include the ranking of coal based on calorific value, the significance of macroscopic properties, and the role of laboratory tests like proximate analysis and total sulfur content. The session highlights how these tests help determine coal's purity and energy potential, guiding students in understanding the fundamental aspects of coal quality assessment.

Takeaways

• 📚 The lecture focuses on the fifth meeting of the course about chemical and biochemical testing of coal, specifically in the context of East Kalimantan.
• 🔬 Two types of tests are discussed: chemical tests for coal quality and geochemical tests to analyze the gas content in coal.
• 👀 Initial analysis of coal can be performed visually or macroscopically by observing color, brightness, and mineral impurities before conducting laboratory tests.
• ⚖️ The rank of coal, known as 'length,' is determined through different stages, with caloric value being a key indicator. Higher caloric value typically means better coal quality.
• 🌟 A visually shiny and dark black coal indicates a higher caloric value and fewer impurities, while duller or grayish coal suggests lower caloric values and more impurities.
• 🧪 Laboratory tests like proximate analysis help determine moisture content, ash content, volatile matter, and fixed carbon of coal samples.
• 💧 Moisture content in coal affects its caloric value, with higher moisture generally lowering the caloric potential.
• 🔥 Volatile matter refers to substances released from coal when heated, which are invisible during the initial inspection but measurable through specific laboratory tests.
• 📊 Proximate analysis, combined with total sulfur testing and caloric value determination, is sufficient to assess the quality of coal for commercial purposes in Indonesia.
• 🧑‍🏫 Fixed carbon is calculated through a simple mathematical formula and is a critical aspect of the overall proximate analysis to assess the energy content of coal.

Q & A

What is the main topic of the lecture?

The main topic of the lecture is about the chemical and biochemical tests of coal, specifically focusing on the fifth class meeting.

What are the two types of tests mentioned for coal quality?

The two types of tests mentioned are chemical tests for coal quality and geochemical tests to determine the gas content in coal.

How can the quality of coal be analyzed without laboratory tests?

The quality of coal can be analyzed visually or macroscopically by observing its color, darkness, luster, and the presence of impurities or minerals.

What are the characteristics of coal with high calorific value?

Coal with high calorific value is described as having a very clear luster and a very black color, with less impurities.

What is the term used to rank coal based on its development stage?

The term used to rank coal based on its development stage is 'rank', which refers to the stages a coal has gone through before becoming coal.

How does the appearance of coal correlate with its calorific value?

A coal sample that is darker and has a clearer luster indicates a higher calorific value, approaching 8903 in this example.

What is the significance of the moisture content in coal?

The moisture content in coal is significant as it affects the coal's calorific value; higher moisture content leads to a lower calorific value.

What is the proximate analysis of coal?

The proximate analysis of coal includes determining the moisture content, ash content, volatile matter, and fixed carbon content.

Why is the total sulfur content important in coal?

The total sulfur content is important because it affects the coal's calorific value and is a requirement for selling or assessing the quality of coal in Indonesia.

What is the difference between fixed carbon and volatile matter in coal?

Fixed carbon refers to the carbon content in coal that does not vaporize when heated, while volatile matter refers to the substances that vaporize and can be released into the air when coal is heated.

How can one predict the quality of coal macroscopically before laboratory tests?

One can predict the quality of coal macroscopically by observing the coal's physical appearance, such as color, luster, and the amount of impurities, to make an initial guess about its quality.