Distribution characteristics of lead-zinc ore resources
1. The mineral deposits are widely distributed, but the reserves are mainly concentrated in several provinces. At present, 27 provinces, regions, and cities have discovered and surveyed lead and zinc resources, but in terms of the degree of enrichment and existing reserves, they are mainly concentrated in 6 provinces, and the total lead and zinc reserves are more than 8 million tons. They are followed by 26,629,100 tons in Yunnan, 16,098,700 tons in Inner Mongolia, 11.224,900 tons in Gansu, 10.773,200 tons in Guangdong, 88.859 million tons in Hunan, and 8.788 million tons in Guangxi, totaling 82,399,800 tons, accounting for 64% of the country’s total lead and zinc reserves of 129.5692 million tons . From the perspective of the distribution of the three major economic regions, they are mainly concentrated in the central and western regions, with lead reserves accounting for 73.8% and zinc reserves accounting for 74.8%.
2. The metallogenic area and metallogenic period are relatively concentrated. Judging from the distribution of super-large and medium-sized mineral deposits that have been explored, they are mainly concentrated in five major mineralization areas including Western Yunnan, Sichuan-Yunnan, Western Qinling? Qilian Mountains, Langshan Mountain in Inner Mongolia, Daxinganling and Nanling. The metallogenic period is mainly concentrated in the Yanshanian period and multiple complex metallogenic periods. According to the “China Domestic Biometal Metallogenic Map Manual”, the metallogenic period of lead-zinc deposits is 6% in Precambrian, 3% in Caledonian, 12% in Hercynian, 1.3% in Indosinian, Yanshan period accounted for 39%, Himalayan period accounted for 0.7%, and multiple periods accounted for 38%.
3. Large and medium-sized ore deposits have large reserves and complex ore types. Among more than 700 mineral deposits in the country, the lead and zinc reserves of large and medium-sized deposits account for 81.1% and 88.4% respectively. There are various types of ore. The main types of ore include lead sulfide ore, zinc sulfide ore, lead oxide ore, zinc oxide ore, lead zinc sulfide ore, lead zinc oxide ore, and mixed lead zinc ore. There are many lead-zinc deposits and copper-zinc deposits dominated by zinc, while there are not many lead-dominated lead-zinc deposits and fewer single-lead deposits.
4. Lead-zinc deposits have complex material composition, many co-associated components, and great comprehensive utilization value. Most mineral deposits are commonly associated with cu, fe, s, ag, au, sn, sb, mo, w, hg, co, cd, in, ga, ge, se, tl, sc and other elements. There are more than 50 kinds of associated elements in the ores mined in some deposits. Especially in the past 20 years, through comprehensive exploration and ore material composition research, it has been proved that many lead-zinc deposits contain high silver content, becoming lead-zinc-silver deposits or silver-lead-zinc deposits. The silver reserves account for more than 60% of the total silver reserves in the country. The production of comprehensively recovered silver in the process of mining, dressing and smelting accounts for 70%-80% of the national silver production, and the gold reserves and production are also considerable.
5. There are many lean ores and few rich ores, and the structure and mineral composition are more complex and less simple. At present, the average grade of lead-zinc is 3.74%, zinc is higher than lead, and the ratio of lead-zinc is 1:2.5, and the ratio of lead to zinc is mostly 1:1.2 abroad. The composition of the ore is complex, and some of the selected ores amount to more than 30 kinds of minerals. Many of the ores are of fine grain size and complex structure, which is a type of refractory ore, which brings difficulties to the beneficiation.