The quality of coal is determined by its quality, gangue, sulfur content, and moisture content. Firstly, the assessment of coal quality should start with strength and hardness; Gangue is classified into flakes and granules, and is divided by the depth of color; Sulfur, distinguished by high, medium, and low; Moisture, bounded by 5%.

Now, let's talk about 6000 kcal of smokeless coal with sulfur content below 1 and less than 3 centimeters. Of course, if there are any discrepancies, please do not laugh at them. This is my personal experience and only for reference.

Sampling. I personally believe that there should be no less than 20 sampling points in the coal pile. The depth of each point shall not be less than 50 centimeters, and the final sample taken away shall not be less than 5 kilograms.

Grab it and squeeze it hard. Generally, the better the strength and hardness, the better the medium.

Grab a handful and spread it in your palm. Look carefully, if there is any gangue, and the gangue is in granular form. Let's first look at the gangue larger than 1 centimeter, how many are there. If there are more than 3, the heat generation is not 6000. If there are no larger ones, look at how many gangue stones are smaller than 1 centimeter. If there are more than 7, there is no 6000. If the gangue is flaky, there is no need to look, there is no 6000. The darker the color of the gangue, the higher the sulfur content, and vice versa, the lower it is.

Sulfur content mainly depends on the copper wires and individual copper crystals in the coal block. 0 Sulfur below 5 is not clearly visible. 0 5-0-0. 7. There are 1 to 2 copper wires or a small amount of dark sulfur on the coal block. 0 7-0-0. 99, with copper wire of less than three strands or dark sulfur of less than 2 bars. 1-- --1. 5. There are obvious copper wires, copper crystals, or 3 to 4 dark sulfur sections. 1. 5-2, there are obvious copper crystals, with individual copper crystals appearing, and no less than 5 dark sulfur sections. 2-3 has obvious large copper crystals.

Generally, coal is divided into high 2 and above, medium 1-2, and low 1 and below. How to make a simple distinction. I have summarized several simple methods. Grab a handful of coal, pinch it a few times, throw it away, check the remaining coal powder on your hand, and rub it a few more times. The darker the color, the higher the sulfur. Black and shiny, not to mention high sulfur coal, with gray tiles and light colors, it is medium sulfur. The color that remains unchanged is less than 1, and the lower the sulfur, the less coal powder remains on the hand. Grab a handful, rinse it clean, and face the sun, you will see a rainbow. The more beautiful the rainbow, the more beautiful it is. The higher the sulfur content, the lower the opposite. Grab a handful and throw it into the burning fire, quickly extending your head over. 0 Below 5, there is basically no taste, low 0. The taste of 5-1 is not very strong, while those of 1-2-2 have a pungent taste. Those with high sulfur content are very pungent.......

Identify moisture, grab it, pinch it, and naturally release it. If the coal in the palm of the hand naturally disperses and leaks out from the gaps in the fingers without a noticeable sense of moisture, the moisture content should be 5%. If there is coal residue, but it does not exceed 1/3, it should be 6%. If it exceeds 2/3, it should be 7%. There are finger marks on the coal weight, 8%, and 9% of water droplets....

The amount of moisture is very important. Although it has little effect on the medium in the short term, over time, especially in terms of heat generation, it has a significant impact.

Of course, people