Luobi Cave Luobi Cave Luobi Cave () is a karst cave under the west face of Yin Ridge (印岭) located north east of Lizhigou Town (荔枝沟镇), from Sanya City, Hainan Province, People's Republic of China. The entrance to the cave is approximately high and wide. Inside the apex reaches a height of with a floor area of about Two large stalactites hang down from the roof like large pens, hence the cave's name. A number of inscriptions carved into the walls of the cave are believed to date to the Yuan Dynasty (1271–1368). One of these refers to the precise date of
Calcium carbonate Currently calcium carbonate is used to neutralize acidic conditions in both soil and water. Since the 1970s, such "liming" has been practiced on a large scale in Sweden to mitigate acidification and several thousand lakes and streams are limed repeatedly. Calcium carbonate is also used in flue gas desulfurisation applications eliminating harmful SO and NO emissions from coal and other fossil fuels burnt in large fossil fuel power stations. Calcination of limestone using charcoal fires to produce quicklime has been practiced since antiquity by cultures all over the world. The temperature at which limestone yields calcium oxide is usually given