Industrial sulfur comes from the smelting and recovery of petroleum, or the purification and recovery of natural gas, which is a by-product of the chemical industry. Industrial sulfur contains high levels of lead, which is highly toxic.
There are three types of natural sulfur: active volcanic sulfur (about 10% impurities), extinct volcanic sulfur mines (about 50% impurities), and natural hot spring sulfur (about 20% impurities). Natural sulfur, also called yellow teeth, contains arsenic, selenium, zinc, thallium, and calcium.
Among them, it is necessary to mention active volcanic sulfur, which is formed by the condensation of high-temperature sulfur gas erupted in the crevices of natural craters.
Most of the active volcanic natural sulfur on the market comes from Indonesia, and the price in China is more than 1,000 yuan per kilogram. It is also produced in Tengchong and other places in Yunnan, China.
Natural sulfur is used in traditional Chinese medicine.
The mining of sulfur from active volcanoes is very dangerous. Most of the workers will not live past the age of 50 due to long-term exposure to poisonous gas, so Indonesians also call it “devil’s gold”. Episode 5 of the BBC documentary “Human Planet” is dedicated to the mining of sulfur from active volcanoes. If you are interested, you can watch it.