The geological structure of the mining area is located in the south wing of Ningwu syncline, west of the southern segment of Linshan-Jianshan fault, south of Taocun volcanic dome, and at the intersection of the northern and western Aoshan volcanic dome. The strata in the mining area are mainly sedimentary pyroclastic rocks of the Longwangshan Formation of the Upper Jurassic, andesite and thin tuff of the Dawangshan Formation of the Lower Cretaceous, which form a syncline with an axial west of 70 ~ 80, and subvolcanic diorite porphyrite intrudes into the core and wings of the syncline.
Pyrite occurs near the contact zone between diorite porphyry and volcanic rocks, mainly outside the contact zone. The ore belt is about 1900 m long, about 190-600 m wide and about 600 m deep, and its occurrence is roughly parallel to the contact zone. The ore body is layered, lenticular and pod-shaped; Ore types include powdery pyrite, massive pyrite and disseminated pyrite; The ore mineral is pyrite, followed by magnetite and hematite; Gangue minerals mainly include sericite, kaolinite, Yingshi, anhydrite and chlorite. The average sulfur content is 16.8 1%, and the sulfur concentrate with sulfur content of 39. 15% can be obtained by mineral processing, and the recovery rate is 87.53%. The accumulated reserves of pyrite are 35,543,200 tons.
There are also many iron ore bodies and anhydrite ore bodies in the deposit. The iron ore bodies are mainly produced in the contact zone and are layered, convex and irregular. Ore types can be divided into breccia, massive and disseminated. Ore minerals are mainly magnetite and hematite, followed by pyrite; Gangue minerals include albite, actinolite, epidote, kaolinite, sericite and anhydrite. The average grade of total iron is 34.54%. Iron concentrate with iron content of 68.56% can be obtained by mineral processing, with a recovery rate of 742,654.38+0% and a cumulative controlled reserve of 39,682,800 tons. The anhydrite ore body is small in scale and has no mining value.
According to the current understanding, the genesis of iron ore bodies belongs to "volcanic-subvolcanic gas-generated high-temperature hydrothermal type", pyrite bodies belong to "volcanic-subvolcanic medium-low temperature hydrothermal type" and anhydrite ore bodies belong to "sedimentary superimposed transformation type".
The discovery of Xiangshan pyrite has gone through a long historical period, from 1940 at the earliest to 45 years at the latest. Generally speaking, it can be roughly divided into the following three stages:
1. Before the founding of New China,
Xiangshan pyrite mine has no record of ancient mining. In 1930s, Sun Jianchu, Xie, Chen Kai, Cheng, Li Yuyao, Zhu Sen, etc. Geological and mineral investigations were carried out in this area, but no written materials related to Xiangshan pyrite were left.
1940, during the Japanese invasion of China, 2.5 square kilometers of electrical, magnetic and geological surveys were carried out here, and then several exploratory trenches and 25 boreholes (1894.40m) were constructed, and shallow ore-rich bodies of Xiangshan pyrite deposit were discovered, with an estimated ore reserve of1400,000 tons. Simple information is contained in the article Nanshan-Xiangshan Sulfide Iron Ore Summary compiled by Huazhong Mining Co., Ltd. 194 1 (unpublished). During the period of 1940- 1945, the Japanese invaders carried out predatory mining, and mined about 480,000 tons of rich ore containing more than 40% sulfur, all of which were transported to Japan.
1946, the resources Committee of the Kuomintang government took over the mine. According to the annual report of Huazhong Mining Bureau of 1946 Resources Committee, the bureau constructed 3 1 borehole around the orebody discovered by the Japanese on 1946, with the workload of 1563.55 m, and the calculated sulfur content was over 45%. During the three years from the resumption of production of 1946 to the suspension of production of 1948, the total ore output was only about170,000 tons, and the mine productivity was low and it was in a dying state.
2. 1949— 1958
1June, 949, the China People's Liberation Army took over Xiangshan Mine, and the people became the owners of the mine, and the history of the mine began a brand-new page. Under the leadership of the people's government of China, the ore output has increased year by year, reaching 1959, with an annual output of179,000 tons.
In order to find out the resources situation and meet the needs of production development and national economic construction, the Chemical Industry Bureau of the Ministry of Heavy Industry mobilized its strength and set up the 342 exploration team of the Chemical Industry Bureau of the Ministry of Heavy Industry from 1953 to 1954. During the construction of the team, in order to alleviate the urgent need of the mine, the ore body was tracked by drilling holes (the workload was about 1000m), and pyrite and magnetite rocks with sulfur content of 30%-40% were found in two drilling holes on the southwest side of the original ore body. However, at that time, the ore body was not delineated, the reserves were not calculated, and the geological situation was not ascertained. It was later confirmed that this is a newly discovered blind ore body.
From July, 1954 to July,1955,342 team Li Shushi, etc. On the basis of geological cataloging of tunnels and arrangement of drilling data during the Japanese-Puppet period, a number of exploratory trenches were built, and a geological map of 0.4 square kilometers was filled in. Then, the Comprehensive Report on Geological Survey of Xiangshan Pyrite Mine was compiled, and the remaining reserves of the ore bodies being mined were calculated. Although its work was rough, it began to pay attention to basic geological work.
The newly established Geological Team 342 started from 1955, and began to explore Shanshan pyrite deposit with little information and experience.
195565438+ 10, Yang, head of exploration technology in Xiangshan mining area, compiled the exploration design. At that time, according to the Sino-Soviet Treaty of Friendship and Mutual Assistance, Soviet experts had entered various industrial departments in China to assist in the work, and the exploration and design had to be examined by Soviet experts. After the examination of Valenzhov experts, the design thinks that the geological structure of the mining area has not been ascertained, and the surface geological work should be carried out in cooperation with geophysical exploration before the design. In the same year 1 to February, Zhang Yunteng, Long Yongshou and Fu Quelai conducted a regional geological route survey, and Long Yongshou and others drew a geological map of the periphery of Wanxiangshan mining area with an area of 18.5 square kilometers, which laid a foundation for studying the geological structure background of the mining area. Since then, the person in charge of exploration technology in Xiangshan mining area has been Long Yongshou.
1In March, 955, Team 342 was renamed Team 804 of Nanjing Geological Exploration Company of the Ministry of Heavy Industry, and Long Yongshou continued to preside over the geological work in Xiangshan Mining Area. At that time, due to the expansion of mine production and the establishment of concentrator to use lean ore, the existing reserves could not meet the production needs, so the superior issued the task of reporting 3.8 million tons of ore reserves in two years: 1955- 1956. In this case, Long Yongshou and others started from April to June in 1955 to strengthen the basic geological work, constructed a number of exploratory trenches, shallow wells and shallow boreholes, filled in the geological map of1:2000 deposit, and compiled1:50,000 and1:65438. Valenzov's experts reviewed the design and approved the construction of 15 boreholes in 4 sections to meet the needs of mining production. At this time, the geological work in this area is at the intersection of exploration and detailed investigation. At the same time, Hu et al. of Team 8 of Geophysical Exploration Team of Geological Bureau of Ministry of Heavy Industry conducted 1∶5000 and 1∶2000 ground electrical and magnetic surveys here, with a working area of 36.2 1 km2, and found 3 electrical anomalies related to Xiangshan Mine, with magnetic anomalies 1.
195511-1956 In April, Long Yongshou and others re-catalogued and sorted out all the surface and underground projects in the Wushan mining area, and then constructed 4275m shallow wells and 556m shallow wells, and made a comprehensive study on the geological and geophysical data of the mining area. 1958, 1956 In May, Valenzov's experts reviewed the iron ore part of the design and put it into practice after it was approved by the Geological Bureau of the Ministry of Heavy Industry.
/kloc-0 completed the field exploration in June 1957, and/kloc-0 submitted the final exploration report of Xiangshan pyrite deposit in February 1958. During this period, Team 804 of Nanjing Geological Exploration Company was changed to Team 804 of Metallurgy Department and Team 342 of Geology and Mining Bureau of Chemical Industry, which was called the Southeast Anhui Geological Team of East China Geological Bureau when it was reported. The captain at that time was Yang, the chief engineer, Li Congzhi, the head of the geological department directly leading Xiangshan mining area, and Long Yongshou, the technical director of the mining area. Long Yongshou, Fu Quelai, Tang,, and others are the editors of the Report. The report was reviewed and approved by the State Reserve Committee on June 7th 1958. The approved reserves are:
Pyrite: 20,532,900 tons, with an average sulfur content of 17. 10%.
Iron ore: 1329500 tons, with an average iron content of 38.23%.
In this exploration, due to the emphasis on basic geological work, accurate and complete first-hand information, careful study of geological structure characteristics of the mining area, and planned and purposeful deployment of exploration work, the understanding of the deposit has made a leap, which has expanded the deposit reserves by more than 10 times, laying a solid foundation for future research work.
After submitting the exploration report, Xiangshan pyrite mine was expanded into a mining and dressing joint enterprise with an annual output of 700,000 tons on the basis of the exploration report, which restored the youth of the mine and entered a prosperous period.
3. 1976— 1985
After 1958 mine expansion, 18 normal production. By 1976, according to the original exploration data and mining conditions, Xiangshan pyrite can be mined for about 10 years. Therefore, prospecting in the edge and deep part of the mining area, extending the service life of the mine and preparing to replace the mine are put on the agenda. At this time, the serial number of southeast Anhui geological team no longer exists. The original 342 team working in Maanshan and the original 322 team working in Wuhu have already merged into the 322 team of Anhui Geological Bureau. Sun Huadong, the chief engineer of the team, and Cao Shunzu, the head of geophysical prospecting technology, analyzed the geological and geophysical characteristics of the mining area by studying the regional metallogenic regularity and using the "three parts and six types" model of porphyrite iron mine, and put forward that it is possible to carry out work in the south of Xiangshan mining area.
During the period of 1976- 1984, the third sub-team of Team 322 successively compiled and implemented the general survey design, supplementary survey design and detailed survey design, with a total drilling workload of 34,800 meters. 1984 completed the field construction, and in June 1985, Report of Maanshan City, Anhui Province.
Pyrite: 150 10300 tons, with average sulfur content 19.82%.
Iron ore: 26.4733 million tons, with an average iron content of 32.56%.
At that time, Ye, the captain of Team 322, Sun Huadong, the chief engineer, Shen, the technical director of the team, Yi Wuqi, the editor-in-chief of the report, and Yang Lianjing, Ren, Chen, Fang, Wang Yijin and Hu Fuou also wrote. The report was approved by Anhui Bureau of Geology and Mineral Resources and won the fourth prize of exploration by the Ministry of Geology and Mineral Resources.
Xiangshan pyrite deposit and Xiangshan South iron deposit are actually a whole, and the ore bodies are connected in the deep. Due to historical reasons, it is divided into two parts with the No.8 section line in the mining area as the boundary. According to 1990, the reserves in the whole region are as follows:
Pyrite: 150 10300 tons, with average sulfur content 19.82%.
Iron ore: 39 170800 tons, with an average iron content of 32.4 1%.
At that time, the tunnel of Xiangshan pyrite mine had been opened to the negative 100 meter elevation of Line 8. The pyrite mine north of Line 8 has been basically mined.
In order to extend the service life of Xiangshan Mine and mine deep iron ore for Maanshan Iron and Steel Co., Ltd., Maanshan Municipal Government organized Maanshan Design and Research Institute of Ministry of Metallurgy, Maanshan Mining Company, Xiangshan Pyrite and Nanshan Iron Mine of Maanshan Iron and Steel Co., Ltd. to put forward the expansion project plan of Xiangshan Mine, and prepared to mine Xiangshan Pyrite-100 m deep. Then, the tunnel system was extended to the south and downward to mine pyrite and iron ore in the south. Team 322 Yi Wuqi compiled ". 199 1 June, when the scheme was being demonstrated, serious floods occurred in Anhui province and heavy rains occurred in Maanshan area. The flood poured into the mine at the rate of 700 cubic meters per hour, which seriously corroded the pump. Invalid after maintenance. On June 15, the mine was flooded and the facilities in the well were damaged. After the disaster, it was considered that the resumption of production had no economic benefits, and the formal application for pit closure and pit expansion scheme and geological exploration and design was not implemented.
Xiangshan pyrite has remarkable social and economic benefits. During the period from 1958 to 199 1 June 4, 3 1.5 years, a total of 400 tons of pyrite1505./kloc-0 was mined, including 389/kloc-rich ore. The original value of fixed assets in the whole mine is 52 102000 yuan, the net value is 6.8 million yuan, there are 3223 registered employees and 920 retired employees, and the profits and taxes are 64 million yuan, which has made contributions to the development of China's chemical industry and the national economic construction.
In the field of geological science and technology, through the efforts and in-depth research of several generations of geologists, mountain pyrite deposits as a typical genetic type are included in scientific research reports and compiled into teaching materials of geological colleges; As an example of exploration type, it has been compiled into the Code for Pyrite Exploration, which provides a learning example for present and future geological prospectors.
Throughout the whole geological exploration history of Xiangshan pyrite mine, the prospecting and exploration must strictly follow the geological work procedures, study the metallogenic geological conditions, find out the ore-controlling factors, and deploy the exploration work purposefully from shallow to deep, from the surface to the inside, so as to avoid blindness and improve the prospecting effect.
Under the policy of "comprehensive exploration, rational exploitation and comprehensive utilization", 1958 approved the iron ore reserves for Shanshan pyrite mine to be13,208,500 tons, but the recovery was only1530,600 tons; According to the statistical data of 1990, there are still 9,840,600 tons of iron ore in Xiangshan mine pit system that have not been recovered by the way in the process of pyrite mining, and have now collapsed. 1990- 199 1 Maanshan City's proposed Xiangshan pyrite expansion project has broken the boundaries between departments and industries, changed the unreasonable phenomenon of single mining left over from history, and implemented the policy of "comprehensive exploration, rational exploitation and comprehensive utilization" stipulated in the Mineral Resources Law of People's Republic of China (PRC), which is undoubtedly a pioneering work with far-reaching significance. Unfortunately, due to floods and other reasons, it has not been realized. If this expansion plan is realized, Xiangshan Mining Association will be rejuvenated again and make new contributions to the development of China's chemical industry, steel industry and national economic construction. This geological team, which has struggled for the development of Xiangshan pyrite mine for nearly 40 years, has been rated as a meritorious geological team by the Ministry of Geology and Mineral Resources, and continues to make new contributions to the expansion of Xiangshan pyrite mine.