Recently, a very large gold mine was discovered in the area of Weishan City in Zhuzhuang Town, Tongbai County, Henan. A total of 16 gold ore bodies were discovered, and the preliminary estimate is that 31.55 tons of gold reserves can be obtained.
Henan has complete strata, complex geological structure, superior mineralization conditions, rich mineral resources, and is one of the major provinces of mineral resources in China. 126 kinds of minerals of various types (157 species including sub-minerals), 73 species of proven reserves (81 species containing sub-minerals), and 85 species of developed and utilized (117 species containing sub-minerals) have been discovered. The area around Weishan City belongs to the Tongbaishan area, which is a famous gold mine enrichment area in China, and the Tongbai-Dabie Mountain area is located at the junction of two major plots in north China and central and south, which is a relatively independent triangular ancient metamorphic rock block. More than 100 gold and silver deposits have been discovered in the area, including 2 large deposits, 3 medium deposits and 10 small deposits. Magmatic activity and tectonic movement are the main causes of mineralization in the Tongbaishan area.
Based on the density of gold of 19.32 tons/m3, 31.55 tons of gold occupies about 1.7 cubic meters of volume. It is equivalent to the size of a Xiaoice box.
Everyone may think that such a size of gold ore can soon be mined, but the fact is not so, in 2014, Songxian Jinmolybdenum Polymetallic Ore Integration Exploration Project in the prospecting breakthrough strategy in the West of Songxian County, Dazhang Town Huaishuping Mining Area found a large gold deposit, with a gold content of nearly 40 tons, is expected to take 42 years to excavate.
In 2016, the Department of Land and Resources of Henan Province discovered a very large gold mine in the deep and peripheral census project of the Laowan Gold Mine in Tongbai County, In the TongbaiShan area of Henan Province, with a gold content of about 105 tons and can be dug for 80 years.
The super-large gold mine in Weishan City has a gold content similar to that of the Huaishuping Mining Area, and it will take almost 40 years to excavate.
Many people may not be able to understand why it takes so long, because the gold in the gold mine is different from what everyone thinks. The metal in the gold mine is elemental to gold and does not form compounds with sulfur or oxygen, so the gold in the gold mine is generally in the form of particles.
Due to the very small particles, coupled with the obstruction of other opaque minerals, the naked eye can not see the gold particles, most of the gold ore storage state includes the naked eye is difficult to observe fine-grained silver gold, tellurium gold, copper gold, quartz vein gold, carbonate vein gold, pyrite fissure gold, pyrite lattice gold, pyrite cladding gold, toxic sand lattice gold, sub-microcapsular gold, organic matter or black shale adsorption gold, ionic gold and so on.
Only rare gold particles larger than 0.1 mm or more are possible to be seen with the naked eye. This granule is also known as prime gold. Natural chunks of natural gold (commonly known as dog head gold) are rare in their own right and are generally used directly for collection.
Therefore, the mining of gold ore is very difficult, because gold is hidden in the quartz vein in the rock, rock gold mining needs people to find the rock containing gold first, the smelting of gold ore needs to select hard rock ore of more than 1 g / ton, or more than 0.2 g / ton of placer ore, or more than 5 g / ton of black shale, high arsenic sulfide ore, ore needs to go through coarse crushing, panning, flotation, cyanide leaching, smelting, electrolysis, refining, by-product recovery and other steps. Large stones are crushed and ball milled into a certain number of fine sands, and then they can enter the re-separation equipment for gold recovery, and a ton of ore can extract a few grams of gold.
The highest known grade gold ore in China from Jilin Huadian and Heilongjiang Sandaowanzi, raw ore grade is extremely high, rich ore section grade of more than 30000ppm, equivalent to a ton of ore 30kg gold, followed by Sichuan Ganzi Prefecture Baiyu County Konglonggou, 7600ppm, equivalent to a ton of ore 7.6 kg gold, Shandong Peninsula richest gold vein, grade of about 1600-2400ppm, these are extreme cases. Generally, rock gold with a grade of more than 5 ppm in China is regarded as a rich ore, that is, one ton of ore contains 5 grams of gold. The industrial grade of gold ore is generally 3 g/t, that is, the amount of gold metal containing 3 g per ton of ore has mining value. In mines with larger production capacity and large-scale mining, the industrial grade can even be further reduced to about 2 grams.
The gold ore body of Weishan City is 1-3 meters thick on average, with a gold grade of 1.15 g/t to 56.9 g/t, and is also associated with lead and zinc ore.
So from here, you can find out why it took so long to mine gold. You also don't think that 31.55 tons, 31.55 tons this number is not small, after all, in 2020 China's gold reserves are only about 1175 tons. The newly discovered gold reserves are 2.68% of China's gold reserves in 2020, which is a big discovery. Even from 2018 to 2019, China's gold reserves grew to 87.1 tons, compared with 87.1 tons, you can find that the 31.55 tons of gold mine found in Henan this time is called a super large gold mine, which is really not exaggerated at all.
According to relevant data, scientists have estimated that the gold content on the earth is about one hundred millionth of the earth's mass. And because the mass of the Earth is about 60 trillion tons, according to the Economic geology association, the world's mined gold is about 190,000 tons, just the size of two Olympic standard swimming pools. The Geographic Association of America estimates that only 51,000 tonnes of gold worldwide remain unmined, and while new gold mines are still being discovered, the discovery of large gold mines is becoming increasingly rare. Most of the current gold production comes from old mines that have been used for decades. That's why gold is so valuable.