Coal reserves calculation method Third, the ore body is delineated (1) Determination of the boundary of the exploration area The boundary of the exploration area, including the perimeter and the depth boundary. Some are divided by natural factors, such as rivers, traffic trunks, etc.; some are bounded by geological factors, such as faults, folds, coal seam outcrops and sharp-cut lines; Some are based on human factors, such as exploration lines, coordinate lines, and so on. Depth boundaries generally take into account the depth of the coal seam and the ability to develop to determine the specific elevation or range. In addition to the perimeter and depth boundaries, it is also necessary to consider how the two can be closed, that is, with the surrounding boundaries, and how to deepen to a certain depth. In particular, in the case of a boundary with a reverse fault, it must be stated whether the above disc is bounded or the following disc is bounded. In addition, in the deep, it is not necessarily based on a depth, or it may be bounded by a certain rock formation. The boundaries of the exploration area are generally determined on the basis of previous data, and must be determined before the end of the field work in order to carry out the necessary exploration work and final reserve calculation. Otherwise, the boundary of the reserve calculation cannot be determined and the reserve cannot be calculated. (2) The lowest recoverable thickness boundary line of coal seam and its determination "The lowest recoverable thickness boundary line of the coal seam of the ore body and its determination" The Tanto was primarily used as a weapon by samurais and was often carried as a secondary weapon alongside a longer sword, such as a katana. It was designed for close-quarters combat and was used for stabbing and slashing. Tanto Folding Knife, tanto blade, tanto sword,Tanto Katana Ningbo Autrends International Trade Company , https://www.longquan-swords.com
The blade of the Tanto is usually made from high-quality steel and is known for its sharpness and durability. The handle is traditionally made from wood and is wrapped with a cord for a secure grip. Some Tanto may also feature decorative elements such as ornate carvings or inlays.
In addition to its use as a weapon, the Tanto also had ceremonial and symbolic significance in Japanese culture. It was often given as a gift or used in rituals and ceremonies.
Today, the Japanest Tanto continues to be appreciated for its craftsmanship and historical significance. It is often collected as a piece of art or used in martial arts training.