Iron ore ditch fortune telling _ iron ore ditch relocation

(1) Overview

The mining area is located at 50 north west of zunhua city, with a linear distance of 10km, and is under the jurisdiction of Xingwangzhai Township. It is 8 1km away from Tangshan in the south, connected by roads and railways, with convenient transportation. After many geological explorations in the mining area, Team 503 of the Ministry of Metallurgy conducted a preliminary exploration at 1956 and submitted a report. 1970 Eighth Geological Brigade of Hebei Geological Bureau conducted supplementary exploration and submitted supplementary exploration report; On the basis of the preliminary work of 1972, the Eighth Geological Brigade carried out fine exploration, controlled the B-level reserves with the grid of 100m× 100m, and submitted the Summary Report on Geological Exploration of Shirengou Iron Mine in Zunhua County, Hebei Province, which was passed by the geology of Hebei Province on June 1974.

Figure 4- 1 Geological Plan of Shirengou Iron Mine

After many geological explorations, Shirengou Iron Mine has constructed 35 boreholes 135, with a total footage of 36848.33m m. By 2003, the proven iron ore resources/reserves were 25,253.7×104t, including the basic reserves1160.5× 65433.

The mine was built in 1970 and designed by Anshan Metallurgical Design Institute. The design scale of open-pit mining is 150× 104t, and the total annual mining and stripping is 900×104t. . The open-pit mining depth is 140 ~ 150m, the stripping ratio is 5∶ 1, and the service life is 14a.

By the end of 2003, the mine had mined 2850× 104t ore accumulatively, and the reserve below the bottom boundary of open-pit mining area was 22390.4× 104t, of which the basic reserve was 8385.7× 104t.

(2) Metallogenic geological conditions

Shirengou Iron Mine is located in the west section of Malanyu anticlinorium in Yanshan Platform Fold Zone of North China Platform. Archean metamorphic basement formed the axis of anticline, Yuanguyu and Mesozoic sedimentary cover formed the north and south wings of anticline, and Yanshanian magmatism formed a series of intrusions with different scales along the east-west structural belt.

Metamorphic rock series of Archean Qianxi Rock Group are widely distributed in this area, mainly medium-fine biotite plagioclase gneiss, biotite plagioclase gneiss, plagioclase amphibolite gneiss, biotite plagioclase amphibolite mixed with multi-layered pyroxene amphibolite, plagioclase amphibolite and a small amount of granulite, garnet plagioclase amphibolite, lenticular or layered magnet quartzite.

The stratum is a monoclinic structure with nearly north-south strike and west dip, and the dip angle of gneiss is generally 60 ~ 80. The development of fault structures in the area has a great influence on the destruction of ore bodies, and there are more than 20 main fault structures.

Magmatic rocks in this area are undeveloped, and only a few dikes are produced, mainly including fine-grained dikes, pegmatite dikes, lamprophyre dikes and diorite and diabase dikes commonly found in deep holes.

(3) Geological characteristics of ore bodies

Shirengou iron ore belt is 5000m long and its exposed surface is 100 ~ 200 m wide. It is divided into Huajiaoyuan section and Shirengou section by F 10 fault. The ore belt is mainly composed of four ore bodies: M 1, M2, M3 and M4.

M 1 orebody: it starts from line 5E in the north and ends at line 26 in the south, with a total length of 2560m. 16-2 1 line is exposed on the surface, and it is a concealed ore body to the south. Due to the influence of fault structure, the ore body is discontinuous along the strike and has been cut off by faults many times. On both sides of the F8 fault near the 20 line, the relative displacement of the ore body reaches 200m, resulting in the ore body. The thickness of ore body is in the north of Line 20, generally 5 ~ 9m, and the thickness in the south varies greatly, generally 7 ~ 20m, with the thinnest being 5.5m and the thickest being 25m. The ore body is lenticular and partly branched and compounded. The overall strike of the ore body is nearly north-south, and it is inclined to the west with an inclination angle of 50 ~ 70.

M2 orebody: distributed in two ore sections. Huajiaoyuan section: it starts from F6 fault in the north and ends at F 10 fault in the south, with intermittent exposure length of 1370m, and consists of three ore bodies, namely M2- 1, M2-2 and M2, with thicknesses of 5, 7 and 9m respectively. The extension depth of both ends of the ore block is shallow, and the extension depth of the middle part is large. Shirengou ore section: It starts from the F 10 fault in the north and reaches the south of Line 28 in the south, with a length of more than 3,000 meters, and the surface is exposed. The shape and thickness of ore bodies vary greatly, and the shallow part is irregular. Affected by faults such as F8, F9, F 18 and F 19, the ore bodies are discontinuous along strike and dip, but the ore bodies on both sides of the fault correspond well. Stone inclusions often occur in ore bodies, which are layered and lenticular. The extension depth of ore body is stable. The thickness of ore body varies greatly along strike and dip, with the thinnest being 2m and the thickest being 23m. The ore body strikes nearly north-south, inclines to the west, and the dip angle changes greatly, ranging from 40 to 45 in the Zanthoxylum Garden section to 45 to 70 in the Shirengou section.

M3 orebody: the total length is 2,360m. Mining confirmed that it is the same ore body as M2, which is layered and lenticular. The thickness varies greatly, locally less than 2m, with a maximum of 14m and a small extension.

M4 orebody: the total length is 880m, and the orebody is bounded by fault F 10. Zanthoxylum bungeanum garden section, 430 meters long and 5 ~ 10 meters thick; Shirengou section is more than 450m long and 15 ~ 20m thick. The ore body extends very deep. The ore body strikes nearly north-south, inclines to the west, and the dip angle is 50 ~ 60.

The chemical composition of the ore is mainly silicon, iron and oxygen, followed by aluminum, calcium, magnesium and titanium, manganese, chromium, potassium, sodium, boron and strontium ... The iron mineral in the ore is mainly magnetite, followed by pseudohematite, with only a small amount of iron silicate. The grade of most ores is above 30%, and a few ores are below 25%. It belongs to magnetite quartzite type lean ore and belongs to the ore to be selected.

(4) Characteristics of magnetic anomalies

Shirengou iron mine is located in Zunhua-Qianxi magnetic anomaly distribution area. The mining area is horseshoe-shaped magnetic anomaly, with a length of 3000m from north to south and a width of nearly1000m. The anomaly center is in the north, with a peak value of nearly 5000nT and a magnetic anomaly area of 2.8km2 Influenced by iron ore bodies in the east, the anomaly shape in the south changes greatly (Figure 4-2).

Figure 4-2 Aeromagnetic Anomaly Map of Shirengou Iron Mine

According to the analysis of anomaly characteristics, the anomaly is a large-scale shallow-buried ore-induced anomaly. According to the abnormal value range 10nT, the ore-bearing coefficient is 30%, and the seam thickness of the rock group in western Guizhou is 20 ~ 30m, the iron ore resources are predicted to be 3× 108t.

(five) the technical conditions for mining the deposit

Shirengou iron mine is a large-scale iron deposit, and its ore-bearing zone is as long as 5000m m. By 700m, the accumulated ore amount of the mine was 2,850×104t, and the reserves below the bottom of the open pit mine were 22,390.4×104t, of which the basic reserves were 8,385.7×104t.