China has the world’s largest antimony reserves, accounting for more than 70% of the world’s proven antimony reserves. The main reserves are concentrated in provinces such as Hunan, Guizhou and Guangxi, among which the Xikuangshan antimony mine in Hunan Province is the world’s largest antimony mine.
China is the world’s largest antimony producer, and its antimony output has long accounted for more than 50% of the global output. China’s antimony mining and smelting technology is advanced, production efficiency is high, and the quality of its antimony products enjoys a high reputation in the international market. China is not only a major producer of antimony ore but also a major exporter of antimony products. A large amount of antimony ore and antimony products are exported to all parts of the world, meeting the global market demand for antimony and its compounds. China’s antimony products occupy an important position in the international market and have an important impact on the global antimony supply chain.
Antimony Deposits Types in China
The major Chinese Sb deposits can be divided into three groups:
- Pure stibnite deposits, which account for about 67% of reserves and are typified by the Xikuangshan deposit, Hunan;
- Sb-Au-W deposits, which account for 21% of reserves and include the Woxi, Hunan, and Gongguan, Shanxi deposits;
- The Dachang deposit, Guangxi typify sulphantimonates-base metal deposits, which account for 12% of reserves.
Based on the ore-bearing rock system, and considering the geological background of the deposit, the mineralization environment, the material composition, the physical and chemical conditions of the mineralization, etc., China’s antimony deposits can be divided into 7 types.
1. Carbonate rock antimony deposits
This type of deposit is located in the carbonate rock system strata. The ore-forming materials mainly come from the ore-forming layer and are formed by the transformation of hot brine. The ore-bearing rock system is a set of carbonate rocks with multiple terrigenous debris. Most of the deposits are dominated by limestone, dolomite, dolomitic limestone, and bioclastic limestone; some deposits are dominated by flint rock. The deposits are restricted by sedimentary factors. The ore body is often limited to a certain layer and filled along the interlayer structure. It is mainly layered, layered, and lentil-shaped, integrated with the strata, and only in some local areas, there is a small angle oblique intersection, with multiple layers; some are mainly vein-shaped. Most of the deposits are large, and some are super large. Typical deposits are the antimony deposits in Hunan Xikuangshan and Yunnan Muli.
2. Clastic rock antimony deposits
The ore-bearing rock system of this type of deposit is marine (local coastal depressions, land margins) clastic rock, namely mudstone, siltstone, fine sandstone, and often intercalated with more impure carbonate rocks. Organic matter and pyrite are common among them. The ore-forming materials come from the ore-forming layer, and the deposits are mainly formed by deep circulation hot brine transformation after the diagenesis period. The ore bodies are mostly vein-like, occurring in the transition area from fine clastic rock to carbonate rock, or in the interlayer fracture zone on the unconformity surface. The deposits are large or medium-sized, and the typical deposit is the Banpo antimony deposit in Guizhou.
3. Shallow metamorphic rock-type antimony deposit
The ore-bearing rock system of this type of deposit is fine clastic rock intercalated with volcanic sedimentary rock, forming volcanic sedimentary ore source layers of Au, Fe, Mn, Cu, Pb, Zn, W, Sb, and Hg. After various transformations, these elements are spatially separated to form tungsten antimony, gold antimony, and gold antimony tungsten quartz vein-type comprehensive deposits. The ore body morphology is mainly vein-shaped and vein-banded. The secondary is lenticular, lens-shaped, etc. The deposits are mostly small and medium-sized, and some are large. Typical deposits include antimony deposits such as Woxi, Longshan, Gongguan, Shaanxi, and Yawan, Gansu.
4. Marine volcanic rock-type antimony deposits
In this type of ore-bearing rock system, both volcanic rocks and volcanic sedimentary rocks are well-developed. The upper plate of the mineralized layer is often volcanic lava, and the ore bodies are present in the altered rocks of metamorphic basalt and claystone (containing tuff, basaltic debris, and basaltic gravel), and the lower plate is gray and thick layered biogenic limestone. The deposits are large or medium-sized, and a typical deposit is the Qinglong antimony deposit in Guizhou.
5. Continental volcanic rock antimony deposit
This type is a new type of antimony ore in my country. The deposit is produced on the edge of the active platform volcanic fault basin. Mineralization is related to continental rift volcanic activity in the late Yanshanian-Himalayan period. Gas and liquid from andesite basalt, andesite, and clinopyroxene provide ore-forming materials. Ore-bearing quartz veins are filled along the fault zones in the erupted lava (or ultra-shallow intrusive veins), and some are produced in the inner and outer contact zones of the veins. The deposit is small and medium-sized, and typical deposits include the Baoshan antimony-gold deposit in Jiangxi.
6. Antimony-tungsten deposits after the magmatic period
The parent rock of this type of deposit is magmatic rock, which is more closely related to the shallow or ultra-shallow small rock bodies and dykes in the middle and late Yanshan periods. Ore-bearing steeply inclined quartz veins are often produced in the contact zone of this type of rock stocks and dykes; some antimony deposits are also produced in the contact zone of the Caledonian granodiorite body, or the inner contact zone of the Indosinian granite; and some deposits are produced in the surrounding rocks at a certain distance from the rock body. Antimony deposits and tungsten, tin, copper, lead, zinc, and other deposits form a horizontal zoning centered on the rock body, reflecting the characteristics of the decreasing mineralization temperature. This type of deposit is divided into two subtypes according to the difference in mineralization mode and mineralization temperature, high-medium temperature hydrothermal replacement filling deposits and medium-low temperature hydrothermal filling deposits. The scale of the deposit is small and medium, and the typical deposit is the Gaoguashan tungsten-antimony deposit in Hunan.
7. Exogenous accumulation-type antimony deposits
This type of deposit is antimony ochre, yellow antimony ore, etc. generated by the oxidation of primary antimony minerals on the surface. After weathering and erosion, they become placer deposits together with natural gold or cassiterite. They are easy to mine and select, but most of them are small deposits, and some are medium-sized. They are mainly distributed in Shanglin, Tianyang, and Debao in Guangxi.
China has accumulated rich experience in antimony mining and smelting technology, especially in the leading position in efficient mining, ore dressing, and antimony smelting technology. Chinese enterprises have advanced technology and equipment in antimony smelting and deep processing and can produce high-purity antimony and its compounds.