Dahengshan Phosphate Mine in Feidong County ()

Dahengshan Phosphate Mine is located 5 kilometers southeast of Qiaotou Town, Feidong County, at the junction of Feidong County and North Korea County, and is under the jurisdiction of Feidong County and North Korea County. The traffic in the mining area is extremely convenient. Huainan Railway and Heyu Expressway pass through the western section of the mining area and are adjacent to the eastern section of the mining area, only 7 kilometers apart. In the north and south of the mining area, there are still several feeder lines connected with them, driving cars, extending in all directions, rain or shine. In addition, from Gao Zhe, Zhongmiao and Chaoxian in the periphery of the mining area, you can enter Chaohu Lake and the Yangtze River by water, leading to the coastal areas.

Dahengshan Phosphate Mine is one of the main medium-sized phosphate mines discovered in Anhui Province, with proven reserves of17.32 million tons. The deposit consists of western ore section and central ore section. Among them, the proven ore reserves in the western ore block10.66 million tons, and the proven ore reserves in the Middle East ore block are 6.66 million tons. The ore body is buried shallowly, and part of it is directly exposed to the surface. The mineral composition of ore is simple, mainly apatite. Phosphate ore has good washability, and the content of harmful impurities in phosphate concentrate meets the standards stipulated by the Ministry of Chemical Industry.

The deposit is located in the middle of the southeast wing of Kanji-Dakangji anticline, and the ore body is located in the lower part of Qiaotouji Formation of pre-Sinian Korean Group, belonging to sedimentary metamorphic phospholimestone deposit. The strata in the mining area are pre-Sinian metamorphic rock series, followed by Tongshan Formation, Qiaotouji Formation and Gegang Formation from bottom to top. Qiaotouji Formation is the main phosphorus-bearing horizon. The underlying Tongshan Formation is a set of shallow metamorphic schists and gneiss, which contain sedimentary metamorphic iron ore. Intrusive rocks are widely distributed in the mining area, including acidic, intermediate-acidic and basic rocks, but gneiss diorite is the main one, followed by granite, amphibole and various dikes.

The western ore block consists of 36 ore bodies, of which 1 is the main ore body, and its ore reserves account for 65.4% of the total ore reserves. The ore body occurs at the bottom of phosphorus-bearing rock section of Qiaotouji Formation, generally 0-35 meters away from the top of mixed gneiss of Tongshan Formation. Stable horizon and good continuity. The ore body is simple in shape, layered, with a length of1200m and an average thickness of 8.28m. The grade of the ore does not change much, and the shallow part is slightly higher, belonging to the ore with uniform grade change, and the average grade of phosphorus pentoxide is 10. 12%.

The Middle East ore block consists of 18 ore bodies. Among them, 1 ore body is the main ore body, and the rest are small ore bodies. The main ore body I exists at the bottom of Qiaotouji Formation, and the surface is continuously exposed like a layer. The length is 3 100 m, and the thickness varies greatly. The maximum thickness is 10.0 1 m, the minimum thickness is only 0.74m, and the average thickness is 4.25m.. There are non-mining areas or non-mining areas along the strike or inclination of ore bodies. Generally speaking, the greater the surface thickness, the thinner the deeper it goes. In addition, the surface thickness of the middle ore block is obviously thicker in the west and thinner in the east, while the surface thickness of the east ore block is thick in the middle and thin on both sides. The ore grade does not change much, generally between 8% ~ 12%, with an average grade of 10.54%.

1959 10 When the original 324 team of the Provincial Geological Bureau conducted geological survey in Feidong area, Li Ying, the technical director of the team, and others discovered phosphorite in this area. It starts from He Yu Highway in the west and ends in Gangtouli in the east, with a total length of 4,790 meters, and the surface ditches are exposed. Drill at the end of the year to understand the occurrence of deep phosphate rock. 1962 in the first quarter, the detailed geological investigation and evaluation report of Dahengshan Phosphate Mine in Feidong was submitted, and the proved reserves of phosphate mine were 2.29 million tons.

1In March, 966, the First Geological Team of the former Ministry of Chemical Industry supplemented some trench exploration projects on the surface on the basis of the work of Team 324 of the Provincial Geological Bureau to further understand the geological characteristics and mineralization characteristics of the surface. August, 1968, drilling exposure control, Dahongshan phosphate exploration. 1June, 970, submitted the geological exploration report of Dahengshan phosphate rock in Feidong, with a phosphate rock reserve of 4.82 million tons.

Although the above two units have successively carried out geological work on Dahengshan Phosphate Mine, due to the conditions at that time, the drilling workload was mainly invested in the shallow part of the western ore section, and there was a lack of control and understanding of the whole mining area. The occurrence of deep phosphorus-bearing strata and ore beds was unclear, and the quality and reliability of most boreholes were poor, which failed to make a correct evaluation of the scale of the deposit. The work done only reaches the level of detailed investigation and evaluation, and it is difficult to be used as the basis for mine construction design.

With the rapid development of agriculture in China, the demand for phosphate rock inside and outside the province is increasing. In order to do geological work well first, expand the prospect of phosphate rock in this area, provide reliable geological data for mines, and speed up the pace of phosphate fertilizer industry in China, Team 327 of the Provincial Geological Bureau organized Ji Li Deng Chao to conduct geological exploration of Dahengshan phosphate rock again at 1975 according to the instructions of the Provincial Geological Bureau. Before the end of 1977, the whole mining area was mainly surveyed to control the scale of the deposit, and the western ore section with good metallogenic conditions was explored in detail according to the geological structure characteristics of the deposit. With the joint efforts of the whole team, especially the hard work of the exploration workers in the mining area, the field work was completed on 1979. 1980, Li Jichao presided over the preparation and submission of the detailed investigation report of Dahengshan phosphate ore section in Feidong and Chaoxian, Anhui Province, and submitted the phosphate rock reserves of10.66 million tons, of which 7.55 million tons were added.

After exploring the western ore blocks, Ji Li Deng Chao Company immediately made a detailed investigation and evaluation of the central and eastern ore blocks. After more than two years' efforts, 198 1 completed the detailed investigation. At the end of 1982, the geological evaluation report on the detailed investigation of the central and eastern sections of Dahengshan phosphate mine in Feidong and Chaoxian, Anhui Province was submitted, and the phosphate reserves were initially proved to be 6.66 million tons, including 4.96 million tons of new ore reserves.

In this work, the proven reserves of phosphate rock 1 7.32 million tons, excluding the proven ore reserves of Chemical 324 Team and Chemical/kloc-0 Team of 4.82 million tons, increased by 8.5 million tons. The expansion of Dahengshan phosphate mine is mainly due to finding out the occurrence of gneiss diorite, and finding new ore bodies under gneiss diorite, which provides an important basis for finding phosphate mines in Chaoxian and Feidong metamorphic rock areas in the future.

Since Dahengshan Phosphate Mine was discovered by Team 324 in June 1959, local people started small-scale open-pit mining. Part of the mined ore is processed into phosphate fertilizer by local township enterprises and sold locally, and part of the ore is transported to neighboring provinces and regions. Since Team 327 re-explored and submitted a detailed exploration report, Anhui Provincial People's Government has included it in the mining plan. It has been officially mined by Jianghuai Phosphorus Plant, with an annual designed mining capacity of 654.38+10,000 tons. The discovery and exploitation of this ore has played a certain role in developing agriculture and alleviating the shortage of phosphate fertilizer resources in Anhui Province and its surrounding provinces.