Distribution characteristics of lithium ore in China

The world is rich in foreign lithium resources. According to the statistical report of US Geological Survey 1999, the proven lithium resource reserves in the world are 7.3 million tons, with a reserve base of 20.2 million tons (excluding China, Russian Federation, Argentina, Namibia, Portugal and other countries).

Lithium mineral resources can be divided into ore lithium and brine lithium. It mainly occurs in salt lake brine and granite pegmatite deposits, in which lithium in salt lake brine accounts for 66% of the world's lithium reserves and more than 80% of the reserve base, and has become the main source of lithium in the world.

China is rich in lithium resources, which can be divided into endogenous deposits, exogenous deposits, a small amount of clay deposits, ancient rock salt deposits and brine deposits in oil and gas fields. Endogenous deposits include granite type, pegmatite type, gas-hydrothermal type and hydrothermal type; Exogenous deposits are mainly Quaternary salt lake brine and underground brine. At present, there are pegmatite, granite and salt lake brine deposits with industrial significance and potential industrial significance.

Pegmatite-type lithium deposits in China mostly occur in geosyncline fold belt and transition zone between uplift and depression in platform area, and the rocks related to the deposits are mainly Hercynian and Yanshanian granites. The deposit is composed of banded pegmatite veins, and the veins often have the structural zoning characteristics of symmetrical and concentric mineral assemblages. The deposit is mainly lithium beryllium, accompanied by niobium, tantalum, rubidium and cesium. The lithium minerals are spodumene, lepidolite and gibbsite. The ore grade is mostly 0.8% ~ 1.4% (Li2O), and the deposit scale is mainly large and medium-sized, which has always been the main mining object of lithium mines in China. These deposits are mainly distributed in Xinjiang, Sichuan, Henan, Hunan, and are also produced in Fujian. It is worth pointing out that there is great potential to find lithium ore in Altay, western Sichuan and Yunnan, western Kunlun and eastern Qinling.

Granite-type lithium ore is also a type being developed and utilized in China, and the ore type is lepidolite. Yichun 4 14 mine in Jiangxi province is a typical representative of this type of deposit. The mine is located in Wugongshan Uplift Area of South China Fold System, and the ore body is located at the top of Yanshanian granite, which consists of three types: fully weathered, semi-weathered and primary ore, with primary ore as the main one. The ore minerals are tantalum-niobium-manganese ore, spar, tantalum-bearing cassiterite and lepidolite. Tantalum is the main mineral and lithium is the associated mineral. The grade of Li2O is low (0.392% on average), but it has large reserves and is easy to mine. This kind of deposit is only found in Jiangxi at present, but there is still a certain prospecting prospect in Nanling area.

Salt lake brine deposits are mainly produced in Qinghai-Tibet Plateau of China. Lithium ore is a modern salt lake type liquid mine, which occurs in intergranular brine, pore brine and lake brine. Lithium-based deposits have high lithium grade, with LiCl content of 2.2 ~ 3. 1g/L, and produce potassium, magnesium, boron and salt minerals, such as Taijinaier Salt Lake in Qinghai, which is the largest lithium-based salt lake brine deposit in China. Lithium ore associated with potassium, magnesium salt and boron ore has low lithium grade, but huge reserves. Northern Tibet Plateau is another big salt lake area in China, and a large number of lithium-containing salt lakes have been preliminarily identified, which is an important metallogenic prospect of lithium resources in brine in China. It is particularly worth mentioning that Zabuye Salt Lake in northern Tibet has huge reserves, high grade (metallic lithium 1g/L) and low ratio of magnesium to lithium, which is a valuable high-quality lithium resource. It can be said that the development and utilization of Zabuye Salt Lake will bring 265,433 benefits to China.