The geological structure of the deposit is located in the north wing of Duxiu Mountain inversion anticline, near the turning point. The core of the anticline is Silurian schist and Devonian quartzite, and its wings are exposed from Carboniferous to Triassic. Due to the compression in NW-SE direction, the NW wing stratum of anticline is normal and the SE wing stratum is reversed. The strata in the mining area strike nearly east-west, tilt to the north, and the dip angle is moderate and gentle, which is a monoclinal structure. The strata below the Lower Triassic bend slowly along the strike and dip, forming a secondary gentle wavy anticline and syncline. The interlayer sliding (squeezing) of the syncline and anticline is a good place for ore body production. There are four main faults in the mining area, except Dushan fault, most of which destroyed the ore body or were filled with intermediate-basic dikes in the later stage. Magmatic rocks are lamprophyre and gabbro, both of which occur in veins. There are more than 40 large and small ore bodies, among which the main ore body 1 is located in Yinkeng Formation of Lower Triassic, which is staggered by faults and becomes two discontinuous parts, I- 1 and I-2 respectively. The former is 16 1.95m in length, 129m in oblique extension,1/2.50m in width, 18.27m in average thickness and148,000 tons in ore. The ore type is simple pyrite. Gangue minerals are mainly quartz, calcite and dolomite. The related ingredients are selenium and gold. The sulfur content of the selected sulfur concentrate is 43.45% and the recovery rate is 94.66%. This is an easily separated ore. Selenium can be enriched to 0.0 14% and can be comprehensively recovered in smelting.
195 1 year, Tang Kecheng and others drew a geological sketch of1∶ 50,000 when conducting geological survey in Hongzhen and Jiangjiazui areas of Huaining County, and the report involved the simple geological conditions of the mining area.
1958, during the climax of nationwide steel action, people found limonite on the surface of this area. In September of the same year, the second geological team of Anqing Branch of Anhui Geological Bureau (later changed to the second team of 326 Geological Team), led by Han Yong, secretary and captain of the Party Committee, and Liu Xiangpei, head of the team's geology, entered this area for geological survey. It took more than two months to find iron ore, with drilling workload of 1 19. 14m and shallow well of 383.90m, and geological sketch of 1∶2000 was completed, and iron ore reserves of 733,700 tons and pyrite reserves of 435,500 tons were obtained. Later, it stopped because the exploration of minerals was wrong.
1March, 959, in order to meet the national and local demands for chemistry, fertilizer and national defense industry, the second detachment of Team 326 returned to Yinzhushan mining area. After three new boreholes were drilled in Yinzhushan pyrite mine in Huaining, Anhui Province, the interim geological report of 1087400 tons was completed in June. In March 1959, it was converted to pyrite exploration, and in September 1960, it was withdrawn for the second time because it was planned to protect grain and steel. The project lasted 1 year and1month, with a total of 3,500m of drilling, 224.3m of shallow wells,138.6m of crosscutting and 3,859m of exploratory trench. Completed geological mapping (1:2000,1:110,000) of 20.5 square kilometers. The proven pyrite reserves are 6.5438+725 million tons (average sulfur grade is 2.65438+0.61%), the surface iron ore reserves are 828,000 tons, and the associated selenium is 2.089 tons. 1September, 962, the geological evaluation report of pyrite in Yinzhushan, Huaining, Anhui Province was compiled and submitted. So far, the exploration of pyrite in this area has come to an end.
1in may, 1975, according to the requirements of the regional heavy industry bureau and the instructions of the provincial geological bureau, team 326 entered the area for the third time to explore the Yinzhushan pyrite mine. In February of the following year, Anqing Heavy Industry Bureau and Team 326 jointly held a symposium on the exploration report of Yinzhushan pyrite deposit, and discussed and passed the Minutes of the Symposium on Geological Exploration Report of Yinzhushan pyrite deposit in Huaining, requiring that orebodies 1 and No.2 be the main exploration targets. 1976 completed the field geology, hydrogeology and drilling work in June, and in July 1977 submitted the reserve report of Yinzhushan pyrite in Huaining County, Anhui Province. The proven reserves of pyrite are 2.096 million tons. After preliminary examination by Anhui Mineral Reserves Committee, the above report points out that there are some problems in this area, such as low industrial reserve ratio, incomplete delineation of ore body boundary, unclear main structures that destroy ore bodies, and no mineral processing test, which need to be supplemented by exploration. 1July 1978 to1June 1979, Team 326 conducted supplementary exploration, and in1October, under the auspices of Luo Jialu, 198 1 65438 compiled and submitted the Geological Exploration Report of Yinzhushan pyrite mine in Huaining County, Anhui Province. The report was reviewed by Anhui Mineral Reserves Committee and passed on February 28th 198 165438, approving the reserves of pyrite of 2.07 million tons. It is considered that the above report can be used as the basis for the construction and design of small mines.
It took 24 years from the first drilling (CK5 1) to the end of supplementary exploration in Yinzhushan pyrite deposit. Geological exploration is intermittent, and it has gone through the repeated process of up and down. It is full of the painstaking efforts and sweat of thousands of geologists and presented to hundreds of thousands of people in Huaining County. It has been 10 years since the formal exploration ended. Due to various reasons, it has not been developed and utilized so far, which is a great pity.