How to identify it with the naked eye

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How to identify coal with the naked eye: I believe that the quality of coal is determined by factors such as its coal quality, gangue content, sulfur content, and moisture level. First, the assessment of coal quality should start with strength and hardness ； Gangue is classified into flaky and granular types, as well as based on the intensity of its color ； Sulfur, distinguished as high, medium, and low ； Moisture, with 5% as the threshold. Now, let’s take 6000-grade smokeless coal with a sulfur content of less than 1 and a thickness of less than 3 centimeters. Of course, if there are any discrepancies, please don’t take it personally; if there are better ways, please feel free to share them. Sampling. In my opinion, when sampling coal piles, there should be no fewer than 20 sampling points. The depth of each point should be no less than 50 centimeters, and the samples taken at the end should weigh no less than 5 kilograms. Grab a handful and squeeze hard. Generally, it refers to strength; the better the hardness, the better the medium. Grab a handful, place it in the palm of your hand, and look closely; if there is gangue, it will be in granular form. Let’s first look at the gangue pieces larger than 1 centimeter – how many there are. If it exceeds 3, the fever is not 6000. If there are no large ones, then check how many gangues are smaller than 1 centimeter; if there are more than 7, then it’s still not 6000. If the gangue is flaky, there’s no need to check; it won’t reach 6000. The darker the color of the gangue, the higher its sulfur content; conversely, the lower the sulfur content. Sulfur content is mainly determined by the copper wires and individual copper crystals in the coal lumps. 0. Sulfur content below 5 is not visibly apparent as sulfur. 0. 5----0. 7. There is 1 to 2 strands of copper wire or a small piece of dark sulfur on the coal lump. 0. 7----0. For 99 grade, there should be less than three strands of copper wire, or less than 2 segments of dark sulfur. 1----1. 5. There are obvious copper wires, copper crystals, or 3 to 4 segments of dark sulfur. 1. 5---2: obvious copper crystals are present, with individual copper crystals appearing; there are no less than 5 segments of dark sulfur. 2-----3 has obvious large copper crystals. Coal is generally classified as high above 2, medium 1–2, and low below 1. How to distinguish it simply. I personally have summarized a few simple methods. Grab a handful of coal, squeeze it a few times, then discard it; check the coal dust remaining on your hands. Squeeze it a few more times – the darker the color, the higher the sulfur content. Dark and shiny – obviously high-sulfur coal; grayish-white with a lighter color indicates medium-sulfur coal. The color does not change upon rubbing; it is below 1, and the lower the sulfur content, the less coal dust remains on the hands. Grab a handful, rinse it clean, and face it toward the sun – you will see a rainbow, and the more beautiful the rainbow, the more stunning it is. The higher the sulfur content, the lower it is; conversely. Grab a handful, throw it into the burning fire, and quickly stick your head in. 0. Below 5, it basically has no taste, at 0. The 5--1 variety doesn’t have much flavor, while the 1-----2 variety has a pungent taste; it’s high in sulfur and extremely pungent. . . . . . . To identify moisture: pick up a handful, squeeze it, and then release it naturally. If the coal in the palm of the hand disperses naturally and seeps out through the gaps between the fingers, with no noticeable sense of wetness, then this moisture content is likely 5%. If there are coal lumps, but less than 1/3 of them, the rate is 6%; if more than 2/3 are lumps, it’s 7%. Fingertip prints on the coal lumps result in a rate of 8%, while the presence of water droplets leads to a rate of 9%. . . . The amount of moisture is very important; although it has little effect on the medium in the short term, over time it has a significant impact, especially on the heat generation. Of course, humans cannot be compared to machines. However, if the fever level as determined by the naked eye differs by 200 calories from that indicated by sulfur tests and laboratory analyses, and the sulfur content differs by 0. With a sulfur content of 4 or less, coal production should not result in losses; if its calorific value is 50 and the sulfur content is 0. Under 2, I think. . . . . .