At present, the amount of mining underground mining of manganese ore mining accounting for about 30% of the amount. The underground mining mines mainly include Hunan Xiangtan, Xiangtao Park, and Gangan Mountain; Guizhou Zunyi and Songtao; Shaanxi Lijiaying; Guangxi Longtou; Liaoning Wafang and other manganese mines. 1. Deposit development method At present, most of them are open to Pingyi and inclined wells. There are also joint developments using Pingyi and inclined wells, such as Zunyi, Wafang and Xiangtaoyuan Phase III mining areas. 2. Mining method The mining methods currently used include the empty field method, the filling method and the caving method. (1) Empty field method China's underground mining of manganese mines is widely used, mainly including Zunyi, Longtou, Huayuan, Qujiashan, Lijiaying, Dounan, Heqing, Songtao and other mines. Nine of the 15 mines in the statistics use the open field method, accounting for 60%. Mines using the open field method use the comprehensive mining method, the room and pillar mining method and the mining and mining method according to the different conditions of the ore body. (2) The caving method includes a wall caving mining method, a stratified caving mining method, and a sublevel caving mining method. The mines adopting such mining methods mainly include Xiangtan Manganese Mine Phase I Mining Area, Tuanxi and Hanyuan Manganese Mine. (3) The filling method includes a water sand filling mining method and a wall filling mining method. Mines adopting such mining methods include manganese mines such as Xiangtan Manganese Mine Phase II Mining Area, Xiangtao Garden, Qigan Mountain, and Tile House. 10K flange is a pressure rating for flange norms of JIS B2220 and KS B1503, the JIS B2220 and KS B1503 full pressure rating class are 5K 10K 16K 20K 30K 40K etc, 10K means 10KG pressure, 10K flange is low pressure flange in JIS B2220 and KS B1503 Flange series but also popular using, the flange type SOP SOH and Blind both have 10K pressure. 10k flanges manufacturer, jis b2220 10k flanges, ks b1503 10k flanges, 10k flanges ff rf, 10k flanges blind Jinan Hyupshin Flanges Co., Ltd , https://www.iflange.com