70 type iron ore scraper
all the top-level equipment in the game are basically proced in each , and the boss in each has his own unique skills, so players must face up to them before they can get the reward.
1. General situation of the deposit
pangjiabao iron mine is located about 44km in the east of Xuanhua City, 23km away from Xiahuayuan coal mine in the southwest. Xuanhua pangjiabao railway line and Xuanhua Chicheng highway pass through the mining area
the mineralization zone of pangjiapu iron ore is about 12500m long and 23.33m thick, which runs through the whole area, with 4 layers of iron ore, and 3 layers of continuous mineralization, with a total thickness of about 6.33m. The strike of ore bed is NE40 °～ fifty ° Direction, inclination se, inclination 25 °～ thirty-five °， Consistent with the occurrence of the stratum, the dip angle to the south becomes gentle (Fig. 2-20, 21)
Fig. 2-20 geological sketch of pangjiabao iron ore area in Zhangjiakou City
(according to China iron ore annals)
CHG dolomite of Gaoyuzhuang Formation; CHT TUANSHANZI formation dolomite; Chch Chuanlinggou formation dolomite; The dolomite of Chch Changzhougou formation; γ— Yanshanian granite; 1 - iron ore body; 2 - measured fracture; 3-inferred fault
Fig. 2-21 exploration profile of 34 typical deposit in pangjiapu, Zhangjiakou City
(according to China iron ore annals)
q-quaternary system; CHG Gaoyuzhuang Formation dolomite; CHD Dahongyu formation quartz sandstone; Chch Chuanlinggou formation sand shale; CHC Changzhougou formation quartzite; 1 - iron ore body; 2-borehole location
the first layer: oolitic hematite. There is siderite about 0.47M thick at the top or bottom of the iron deposit, which occurs in layers, with a length of about 12500m and a thickness of about 2.24m
The second layer is oolitic and nephritic hematite with a thickness of about 1.27mthe third layer: renal hematite, 0.82M thick, the ore body is basically continuous
the fourth layer: renal hematite, only seen in some sections, occurs as stratoid
the TFE grade of the first layer iron ore is about 49.21%, the second layer iron ore is about 41.90%, the third layer iron ore is about 42.99%, and the average grade of the whole region is about 45.28%
The main ore type is hematite, followed by magnetite, siderite and limonite, and occasionally oolitic pyrite. The ore structure can be divided into oolitic, reniform and massive. The oolitic structure is mostly seen in the upper part of the ore belt, while the reniform structure is seen in the bottom of the ore belt. In the middle of the ore belt, there are both oolitic and reniform structures, and the oolitic structure is the main one. Ore minerals include hematite, siderite, magnetite, limonite, pyrite, etc The ore is the main deposit of Xuanlong type iron deposit, and its genetic type is Proterozoic shallow sea sedimentary iron deposit. The mining area, including xiacang, tianjiayaobakou and pangjiapu, is one of the raw material bases of Xuanhua Iron and steel company. The total proven reserves of iron ore in the whole region are 83.171 million tons, including 36.998 million tons of a + B grade and 72.423 million tons of a + B + C grade ore (China iron ore annals, Yao peihui et al., 1993) Metallogenic geological background and regional geophysical characteristics (1) metallogenic geological backgroundgeotectonically, this area belongs to the northwest end of Yanshan parageosyncline, the southern margin of Inner Mongolia platform anticline, and the iron ore enrichment section is parallel to the edge of the anticline. According to the research results of Proterozoic, the northwest end of Yanshan parageosyncline can be divided into secondary geological structural units, which is called Xuanlong syncline
the fold basement of Xuanlong syncline is the Neoarchean Sanggan group, which hardened before the Luliang movement. It is a metamorphic volcanic sedimentary formation, composed of biotite plagioclase gneiss, garnet bearing biotite plagioclase gneiss, graphite bearing plagioclase granulite, marble, migmatite, garnet plagioclase amphibolite and hornblende diopside granulite (Fig. 2-22a). The Gaoyuzhuang Formation of the great wall system is covered on the basement by unconformity, and the thickness near pangjiabao is more than 1500 m. In the unconformity above Gaoyuzhuang Formation, there is upper Jurassic qiongjishan formation with different thickness and mainly andesite. There are Yanshanian acid magmatic intrusions in the area, which can be divided into two stages. The first stage is red coarse-grained granite, which intruded before late Jurassic; The second stage is gray biotite granite, which intruded in the late Jurassic and early Cretaceous. The former is close to the west end of pangjiabao mining area, which reces hematite to magnetite
(2) according to the regional geophysical characteristics1:200000 aeromagnetic △ t isoline plan (Fig. 2-22d), pangjiabao mine is located in the weak magnetic anomaly zone near EW direction in a wide range of low, gentle and stable background field, corresponding to the quasi elliptical high magnetic anomaly near EW direction, with the anomaly intensity of 200-400nt. According to the results of aeromagnetic pole processing (Fig. 2-22e), the local anomalies are more prominent and move northward as a whole. Pangjiabao iron mine is located in the South gradient zone of quasi elliptical high magnetic anomaly distributed in EW direction
1: on the 200 000 Bouguer gravity anomaly map (Fig. 2-22b), pangjiabao iron ore deposit is located in the gradient zone on the north side of stable wide gentle gravity high anomaly near EW strike; In the resial gravity anomaly map (Fig. 2-22c), pangjiabao iron mine is located at the intersection of NW trending resial gravity high anomaly zone and NW trending gravity high anomaly zone
(1) the deposit is located in the north wing of Xuanhua Houcheng syncline, that is, from the Yantongshan of Xuanhua to the East through pangjiapu, Xinyao and dalingpu to the east of Chicheng, with gentle and wide folds. The syncline structure is mainly composed of Proterozoic great wall system, and the stratigraphic strike is ne50 ° Direction: se, dip angle: 250-35 °， The dip angle becomes gentle to the southeast. Affected by granite intrusion and fault activity, the strike and dip of local strata and ore beds have changed in the west end The Changcheng system consists of Changzhougou formation, Chuanlinggou formation, TUANSHANZI formation, Dahongyu formation and Gaoyuzhuang Formation from bottom to top, and the iron ore bodies mainly occur in Changzhougou formation and Chuanlinggou formationChangzhougou formation: mainly quartzite, about 135m thick. The lower part is white quartzite, the lower part is medium thick fine-grained quartzite, and spotted limonite is common at the bottom; Upward, there are purple thin iron bearing sandy shale, sandstone, pink quartzite and purple thin quartzite, with coarse interlayers and ripple marks; The upper part is white quartzite. The interlayers and ripple marks are well developed
Chuanlinggou formation: mainly shale, about 70m thick. The lower part is the ore bearing zone, and from bottom to top is sand shale, ore bearing bed and sand shale; The upper part is shale series, the lower part is black dense homogeneous bedding carbonaceous shale, the top is often intercalated with a thin layer of siderite, and the upper part is gray green blade shaped subtle bedding shale
The lithology of TUANSHANZI formation is mainly dolomite, about 200m thick; Dahongyu formation is mainly composed of sandstone with a thickness of about 150m; Gaoyuzhuang Formation is mainly composed of dolomite with a thickness of 955m
Fig. 2-22 regional geological mineral resources and geophysical exploration profile of typical deposit of pangjiabao sedimentary iron ore in Zhangjiakou City
a-geological mineral resources map; B-bouguer gravity anomaly map; C-resial gravity anomaly map; D-aeromagnetic Δ T isoline plan; E-aeromagnetic Δ T-pole contour map; F-aeromagnetic Δ T-pole vertical first derivative isoline plan
1-quaternary system; 2-jurassic continental intermediate acid volcanic rocks and pyroclastic rocks; 3 - Middle Jurassic coal bearing sedimentary clastic rocks and continental intermediate basic intermediate acid pyroclastic rocks; 4 - Mesoproterozoic light metamorphic dolomite and clastic rock; 5-archean Proterozoic gneiss and plagioclase amphibolite; 6-archean tonalite gneiss; 7-archean complex; 8 - Archean lherzolite, biotite plagioclase gneiss and plagioclase amphibolite; 9 - Archean lherzolite and biotite plagioclase gneiss; 10 - Cretaceous granitoids; 11-jurassic syenites; 12 - Paleoproterozoic syenogranite (Note: geological map scale 1:250000, gravity and magnetic data scale 1:200000)
(2) local geophysical characteristics
1:100000 aeromagnetic △ t isoline plan (Fig. 2-23b), pangjiapu iron ore area is located in the eastern gradient steep change zone of local elevated magnetic anomaly near EW strike in large area of elevated magnetic field, The anomaly curve is relatively wide and gentle, with high magnetic anomaly intensity of about 600nt in the West and obvious negative anomaly in the north; The high magnetic anomaly intensity of the mining area is about 400nt, and the associated negative anomaly in the north is not obvious. According to the results of aeromagnetic pole processing (Fig. 2-23c), the local anomaly is more prominent and moves northward as a whole. The mining area is located in the east end of the ellipse like magnetic high anomaly near EW direction, with obvious negative anomaly in the south
Fig. 2-23 geological mineral resources and geophysical exploration map of typical deposit area of pangjiabao sedimentary iron ore in Zhangjiakou City
a-geological mineral resources map; B-aeromagnetic △ t isoline plan; C-plane contour map of vertical first derivative of aeromagnetic △ t pole; D-aeromagnetic △ t polar isoline plan
1-quaternary system; 2 - Jurassic Baiqi formation combined with strata; 3-jurassic qiongjishan formation; 4-jurassic Mentougou formation; 5-sinian is higher than Zhuang formation; 6 - Wumishan formation of Jixian system; 7-yuguzuizi formation of Archean; 8-archean single tower subgroup; 9-biotite granite; 10 - porphyry granite; 11 quartz syenite porphyry; 12 quartz syenite porphyry; 13-syenite porphyry
4. Physical properties of rocks (ores)
statistical results of magnetic parameters of rocks (ores), average magnetic susceptibility: iron bearing sandy shale is 11.21 × 10-5SI The Archean metamorphic rock is 2611 × 10-5SI Sandstone is 13.02 × 10-5SI 22 0 × 10-5SI The dolomite is 3.75 × 10-5SI The granite is 554 × 10-SI
The average density of limonite is 4.5g/cm < sup > 3 < / sup >; The Archean metamorphic rocks are 2.67g/cm < sup > 3 < / sup >; 64g / cm < sup > 3 < / sup >; 70 g / cm < sup > 3 < / sup >; 80 g / cm < sup > 3 < / sup >; The granite is 2.54g/cm < sup > 3 < / sup > The results show that the magnetic susceptibility of pangjiapu Xuanlong type iron ore and Changcheng series is lower than that of Archean metamorphic rocks, and most of them show negative magnetic field or weak low magnetic anomaly in the magnetic field, and large high magnetic anomaly fields are the reaction of Archean metamorphic rocks; The density values of pangjiapu Xuanlong type iron deposit and Changcheng system are higher than those of Archean metamorphic rocks, and most of them show local gravity high anomaly in gravity field (1) Archean metamorphic rock is the source bed of pangjiapu iron deposit, which can be used as an indirect prospecting indicator (2) Changzhougou formation and Chuanlinggou formation of Changcheng system are the main host rocks, which can be used as important prospecting indicatorsgravity and magnetic anomaly marks:
(1) the local anomaly of the same height of gravity and magnetic or the local gravity high anomaly (the magnetic anomaly is not obvious) can be used as an important prospecting mark
(2) the aeromagnetic regional background is a negative magnetic field, and the superimposed gravity and magnetic zonal large anomalies on the regional background usually reflect the ancient metamorphic rocks, and can also be used as an indirect prospecting indicator (indicating the ore source bed)1、 General situation of the deposit
zhuya type iron deposit is represented by dianzi iron deposit in Qingzhou City, Shandong Province, which belongs to weathering leaching type iron deposit. The amount of iron ore is 66.2 million tons. The TFE content of limonite ore is 40% - 55%, the highest is 61.74%, and the average is 45.52% (rich ore 49.92%, lean ore 32.83%). The highest TFE content of siderite ore is 30.74%, with an average of 29.79%. The associated element Mn is 0.8% ～ 1.5%, the highest is 3%; Ti and V are in trace amount, which are similar to iron; S＜0.2％ Cu0.03% ～ 0.07%, the highest 0.1%; P＜0.2％
The geological map of dianzi iron ore area in Qingzhou, Shandong Province is shown in Figure 8-4
Fig. 8-4 geological sketch of dianzi iron ore area in Qingzhou, Shandong Province
1. Strata in the area are upper Cambrian Gushan formation, Changshan formation and Fengshan formation, lower Ordovician Yeli Liangjiashan formation and Middle Ordovician Majiagou formation. The strata related to mineralization are Fengshan formation of Upper Cambrian and Yeli Liangjiashan formation of Lower Ordovician
(1) Fengshan formation of Upper Cambrian is divided into two lithologic sections according to lithology. From bottom to top: member 1: the upper part is banded and bamboo leaf limestone, and the middle part is purple bamboo leaf limestone and mudstone. The argillaceous matter is high, which is not concive to mineralization. The lower part is mainly banded limestone with purple bamboo leaf limestone and mudstone. The thickness is more than 90 M The second member has a total thickness of 120 m and is divided into seven natural layers from top to bottom: (1) micro fine grained dolomite and dense massive limestone with high argillaceous content 2) Chain like cryptocrystalline limestone is dark gray cryptocrystalline limestone 3) Granular limestone, granular variable granular structure, is mainly composed of sand debris 4) The banded limestone is a bamboo leaf limestone with cryptocrystalline microcrystalline structure and high argillaceous content 5) Phenotypic limestone, high calcium limestone composed of cryptocrystalline and microcrystalline calcite, is the main ore bearing horizon 6) Dolomite, containing more than 90% dolomite, is mostly mineralized 7) Banded granular dolomitic limestone is composed of dolomite and calcite, which contains more than 50% granular fragments. It can also be enriched into ore in favorable structural position (2) the total thickness of the lower Ordovician Yeli Liangjiashan formation is 70 M. The lower part is brown yellow light flesh red thick layer with argillaceous dolomite, and the upper part is gray white light red dolomite with chert nole and chert belt. The mineralization is strong and it is the ore bearing horizon The mining area is located in the north part of Zihe fault zone, mainly in fault structure. The structures related to mineralization are NNE, near Sn and nee1) NNE trending fault: the Zihe main fault represented by F < sub > 9 < / sub > is tens of kilometers long with a strike of 20 km °～ thirty °， It is slow wavy, inclined to se, with an inclination of 80 ° It is a high angle thrust fault with a vertical distance of 120-270 M. After many times of pre tension and post torsion activities, a large number of interlayer fractures are proced, which provides a good space for ore filling and deposition
(2) near Sn fault: in the east of the mining area, it is 1200 m long and 5 m strike °～ ten °， Dip NW, dip 80 ° about. In the deep part of the fault, the development of the ore storage structure is restricted to the East, and the mineralization is terminated nearby (3) nee trending fault: strike 55 °～ seventy °， Dip NW, dip 80 ° It is also an important ore bearing structure There are only pyroxene diorite, pyroxene bearing diorite porphyrite, biotite diorite, diorite, diorite porphyrite in the form of batholith and Lahuang porphyry, eclogite, diorite porphyrite in the form of vein. Pyroxene diorite, diorite and Lahuang porphyry are the most common(II) ore body features are shown in Fig. 8-5. Dianzi iron deposit is composed of concealed ore bodies, which are distributed along NNE direction, with a total length of 3500 m and a width of 300-1500 M. Taking the f < sub > 9 < / sub > fault as the boundary, it is divided into two parts: fault East and fault West. There are 10 ore bodies in fault East and 1 ore body in fault West. The ore bodies are mainly stratoid and locally lenticular, and their morphology is controlled by fault structure and interlayer structure. The Cambrian Fengshan formation is the main ore bearing horizon, and only a few small ore bodies occur in the Ordovician Sanshanzi formation. The strike of ore body and F9 fault is (20 ° They are consistent and tend to NW
The total thickness of the ore belt to the east of the fault varies from several meters to 240 meters, and the ore bodies in the ore belt overlap in parallel, with a vertical interval of 6-80 meters. The thickness of each ore body in the ore belt is generally between several meters and tens of meters, and the maximum thickness is 105 M. The west side of the fault is a single ore body with a thickness of about 10 m and a maximum thickness of more than 40 m. The thickest section of the ore body is distributed in the south of the mining area, on the east side of F < sub > 9 < / sub > and away from F < sub > 9 < / sub > the thickness of the ore body graally becomes thinner until pinchout The ore body to the east of the fault is mainly composed of limonite ore, followed by siderite. Siderite ore is mainly distributed in the south of line 12, in the lower part of the ore belt. The lower part of ore body V and ore bodies VIII, IX, X are basically composed of siderite ore, and a small amount of siderite occurs in other ore bodies. The orebody to the west of the fault is composed of limonite ore (3) ore characteristics the ore in the mining area is divided into limonite ore and siderite ore The mineral composition of limonite ore is limonite and goethite; The second is wurtzite, hematite and hydrohematite; A small amount of pyrolusite tetrahedrite, pyrolusite, Specularite, pyrite, chalrite, magnetite, anatase, etc. Limonite and goethite are the main ore minerals. The gangue minerals are mainly calcite, dolomite and quartz; A small amount of barite, argillaceous matter, olivine, biotite, diopside, actinolite, apatite, silicalite, zircon, etc
Fig. 8-5 profile of dianzi iron ore exploration line
mineral composition of siderite ore: ore minerals are composed of siderite, pyrite, chalrite, Specularite and magnetite; Gangue minerals include quartz, ankerite, chlorite and barite, followed by biotite, diopside, carborunm, apatite and zircon
The structure of limonite ore is grid, colloidal and earthy; The siderite ore is of medium fine grained meta crystalline structure According to the structural characteristics, limonite ores can be divided into compact massive, honeycomb, silty granular, banded, grape like and grid like structural types. Among them, dense massive, honeycomb, powder granular and grid ores are common, which are the main ore types of limonite orebody. Dense massive, honeycomb and powder granular ores are rich ore types; The gridded ore belongs to lean ore type There are two kinds of siderite ore, coarse siderite ore and fine siderite ore. Siderite ore bodies are mainly composed of the former, while the latter is rare, and they are distributed in the edge of the ore body The amount of limonite and siderite is not much, but they are also common (4) wall rock alterationwall rock alteration includes carbonation, limonitization, silicification, baritization, pyritization, brass mineralization, Specularite mineralization and rock fading
At present, there are many understandings about the genesis of zhuya type iron deposit. The similarities of these understandings are that they all affirm the important role of faults in mineralization and ore control. The differences are that there are disputes about the source of minerals According to the interdependence of limonite and siderite in dianzi iron deposit, the metasomatism of ore bearing hydrothermal solution and the data of stable isotope measurement, it can be considered that the filling metasomatism of medium low temperature ore bearing hydrothermal solution forms the deposit base with siderite as the main body, which is transformed by oxidation leaching, and finally forms the instrial deposit with limonite as the main body with new structural characteristics, The genesis of the deposit should be determined as modern weathering sedimentary iron deposit, i.e. weathering leaching iron deposit. The ore-forming process has roughly experienced the following two stages (Fig. 8-6) In the siderite mineralization stage, the intermediate basic and alkaline ultrabasic magma in the deep crust derived ore-bearing hydrothermal solution e to differentiation, which migrated and diffused along the structural belt; Along the way, it carried and dissolved the useful components in each horizon, and under the drive of structural inheritance activities, it filled in the ore hosting structures of different surrounding rocks in a medium low temperature state, forming a layered siderite body dominated by filling and metasomatism(1) iron source
the lower Paleozoic strata, especially the dianzi iron ore-forming wall rock, have little Fe content, only a few thousandths, which should be regarded as the external conditions of favorable ore fluid metasomatism, or can only provide part of the iron, but can not be regarded as the source of ore, ore-bearing hydrothermal solution is the main source of iron ore. According to the results of oxygen isotope determination of siderite in dianzi iron deposit, δ< Sup > 18 < / sup > O is 9.03 ‰ - 11.16 ‰, and the surrounding rock (limestone and dolomite) of the ore body δ< Sup > 18 < / sup > o ranges from 16.38 ‰ to 25.06 ‰. It can be seen that the sources of oxygen in siderite and surrounding rock are different. It is speculated that the oxygen in siderite is related to ore bearing hydrothermal solution. Carbon isotope determination of Siderite δ< Sup > 13 < / sup > C ranges from - 2.03 ‰ to - 8.4 ‰, which is related to magmatic carbonatite δ< Sup > 13 < / sup > C values (- 5.0 ‰～ - 8.0 ‰) are equivalent, which indicates that siderite is the proct of magmatic hydrothermal solution. sulfide δ< Sup > 34 < / sup > s ranges from 6.4 ‰ to 16.8 ‰, which also shows the characteristics of magmatic hydrothermal sulfur. The siderite in the mining area is a semi self fluxing ore, and the content of SiO < sub > 2 < / sub > is between 10% and 20%, which is significantly higher than that of non mineralized wall rock and sedimentary siderite. The high content of SiO < sub > 2 < / sub > in siderite is the result of ore bearing hydrothermal metasomatism, which also indicates that both Fe and s come from deep ore bearing hydrothermal solution
(2) physicochemical conditions of ore-forming.
Fig. 8-6 metallogenic model of zhuya type iron ore. In addition, the quartz vein and barite vein in siderite are typical hydrothermal minerals of medium and low temperature, which are consistent with the formation temperature of siderite
The above characteristics of siderite indicate that siderite is formed by filling metasomatism of medium and low temperature hydrothermal solution, and it is formed in relatively closed conditions and environment with low pH and eh values. The ore bearing hydrothermal solution comes from deep medium basic and alkaline ultrabasic magma Limonite is the main body of dianzi iron deposit. Limonite is mainly formed by weathering and leaching of siderite, and a few of them are directly formed by the ore-forming process of succeeding siderite. In the late stage of siderite mineralization, e to the further development of tectonic activity, the environment is relatively open and the EH value increases. In addition, with the rise of ore solution, the alkaline components in surrounding rock are continuously absorbed, which promotes the transformation of solution from acidic to alkaline. With the change of oxidation conditions, divalent iron is transformed into trivalent iron, and alkaline medium accelerates its precipitation to form limonite directly But on the whole, most limonite is the supergene oxidation proct of siderite. The limonite orebodies in dianzi iron deposit are mostly located above siderite orebodies, some of which are limonite in the upper part and siderite in the lower part of the same ore bed. The above situation is related to the oxidation interface of the mining area, that is, below the oxidation interface is siderite, and above the oxidation interface is limonite. The depth of oxidation interface in dianzi mining area is 400 m ± Elevation - 240 m ±， The resial siderite orebodies in some shallow areas are the result of insufficient oxidation in a relatively closed environment. Oxidation not only changes the ore type, but also expands the scale of the deposit and improves the ore grade e to the addition of iron from other sources. With the change of siderite to limonite, the structure of ore is changedThis paper mainly refers to the iron deposits which are controversial in origin and difficult to determine at present, such as Bayan Obo iron deposit in Inner Mongolia and Shilu iron deposit in Hainan. Therefore, they are temporarily included in the category of other types of iron deposits
The Bayan Obo iron deposit is located to the north of Baotou, Inner Mongolia. It is a huge iron rare earth (NB) deposit in China and the largest LREE deposit in the world. The iron ore reserves are also very large (1.468 billion tons). Geotectonically, the deposit is located in the northern margin of Inner Mongolia axis of Sino Korean platform, adjacent to Inner Mongolia EUGEOSYNCLINAL orogenic belt in the norththe deposit occurs in the early Mesoproterozoic Bayan Obo Group, which is mainly composed of quartzite slate, phyllite and dolomite, forming a set of shallow marine clastic rock formation, forming a synclinorium trending nearly East-West in the area. Baiyun syncline is a secondary syncline, its core is composed of black potassium rich slate, and its two wings are dolomite. The mineralization of Fe, re and Nb in this area is mainly distributed in this syncline
The intrusive rocks are mainly distributed in the south, including gabbro, gabbro diorite and biotite granite. Biotite granite belongs to the intermediate composition of calc alkaline and alkaline granite according to its chemical composition. Its isotopic age ranges from 255 to 264 Ma and belongs to Hercynian period The ore bearing zone is 16km in east-west direction and 1-2km in South-North width. The whole mining area can be divided into three ore blocks, namely east mine, main mine and west mine According to the types of gangue minerals and iron bearing minerals, six main types of iron ore can be divided: Fluorite - spomene - tremolite - magnetite and hematite type, fluorite - hematite and magnetite type, spomene - magnetite type, tremolite magnetite type, dolomite - magnetite and siderite type, biotite - magnetite type. In addition, there are niobium and rare earth ores of spomene type, dolomite type, diopside type and biotite type. Among these ores, magnetite and hematite only play a secondary role Metasomatism is very common in the mining area, and the alteration can be divided into four stages:
1) magnesium skarn stage: it occurs in the contact zone of biotite granite and dolomite in the east of the mining area. The minerals are diopside, phlogopite, brucite, tremolite, fluorite, magnetite, ceric apatite, thorite, monazite, epidote, Cerite, pyrochlore and calcium niobate
(2) early stage of sodium and fluorine metasomatism: it is widely developed in the East, main and west ore blocks, mainly characterized by sodium diorite, biotite and fluorite, accompanied by niobium, rare earth and iron mineralization of sodium amphibole type, dolomite type, fluorite type and biotite type (3) late stage of sodium and fluorine metasomatism: mainly developed in the main ore and East ore block, and superimposed on the early procts of sodium and fluorine metasomatism, forming spomene type niobium and rare earth iron ore, sodium amphibole type niobium and rare earth ore, and banded fluorite type niobium and rare earth iron ore (4) late vein mineralization and alteration stage: various metasomatic veinlets were formed, and the minerals seen included amphibole, spomene, quartz, albite, fluorite, calcite, barite, pyrite, pyroxene, Baotou ore, bastnaesite, Huanghe ore and emeraldthe iron content of the ore is 31% ～ 36%, with an average of 34.01%, the rich ore is 45% ～ 55%, the iron content of the ore is tr < sub > 2 < / sub > o < sub > 3 < / sub > 2% ～ 8%, (Nb, TA) < sub > 2 < / sub > o < sub > 5 < / sub > 0.05% ～ 0.1%, P 0.3% ～ 1%, F 2% ～ 10%
At present, there are many divergences on the genesis of the deposit, mainly including the following understandings: (1) special high temperature hydrothermal metasomatism; ② Sedimentary metamorphism hydrothermal metasomatism; ③ The origin of carbonate magma intrusion; ④ Volcanic sedimentary origin of carbonate magma containing rare metals2. Shilu iron ore is a famous large-scale rich iron ore deposit in China and a proction base of steel-making ore. The deposit is located in the south margin of South China orogenic system and the northwest of Hainan uplift. The ore bearing strata are Neoproterozoic [(975 ± 6) MA] Shilu group is a set of light metamorphic slate phyllite, meta siltstone, quartzite and dolomitic marble with flysch like sedimentary characteristics. The late Hercynian (249 MA) granite occurred nearby, so it suffered contact metamorphism (metasomatism) and formed diopside tremolite skarn and garnet skarn
Fig. 2-10 profile of line 8A of Hainan Shilu Iron Mine. The copper cobalt orebody occurs in the lower part of the iron ore body. The iron ore is mainly composed of scale hematite and quartz, with trace magnetite and siderite locally. The ore minerals of copper cobalt ore bodies are mainly chalrite, pyrite, cobalt bearing pyrite, cobalt bearing pyrrhotite and cobaltite. Gangue minerals are mainly quartz, diopside, tremolite, garnet, barite and calcite
The average TFE of iron ore is 51.15%; The average content of Cu and CO is 1.58% and 0.307%, respectively. AG, Ni and other beneficial elements are also associated in the copper cobalt ore. Ore structure, rich ore is dominated by sheet structure, poor ore is dominated by massive and banded, followed by breccia In the 1950s, most of the deposits were considered to be skarn type. In the early 1970s, sedimentary metamorphism was dominant, but some people thought it was volcanic sedimentary iron ore or sedimentary metamorphic hydrothermal enrichment. The author has made a short-term investigation in Shilu iron mine, and has also investigated Precambrian sedimentary metamorphic iron ore deposits in the former Soviet Union's krivorok and Kursk, and in Anshan, Eastern Hebei and Xinyu of China. It is considered that although Shilu iron mine has some similarities with these Precambrian sedimentary metamorphic iron ores, there are more differences than similarities, so it is not easy to compare them. Therefore, the causes are worth further discussion1、 It is summarized that
porphyrite type iron deposits occur in or in the contact zone of sodium rich pyroxene basaltic andesite porphyrite gabbro diorite porphyrite and diorite porphyrite. The typical deposits occur in the Mesozoic continental volcanic fault basin in Nanjing Wuhu area, China, and are closely related to the igneous intrusion of basaltic andesitic magma. The metallogenic type of porphyrite iron ore is shown in Table 1
Table 1 Classification of porphyrite type iron ore metallogenic types
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Fig. 6 5-line magnetic anomaly profile of Baixiangshan iron deposit in Ningwu, China
Fig. 7-line gravity and magnetic anomaly profile of Gushan Iron Deposit in Ningwu, China
8) gravity normalized total gradient, when its maximum value is greater than 3.06, the anomalies are mostly caused by ore bodies, The center of the positive gradient anomaly corresponds to the position of the gravity center of the ore body, and the width of the semi extreme value corresponds to the horizontal extension of the ore body
If the apparent magnetization is very high, it is mainly caused by magnetite In electrical sounding, the orebody corresponds to low resistivity, and the gradient zone anomaly between high resistivity and low resistivity often corresponds to contact zone and orebody (1) between high gravity and low gravity, there is obvious gradient zone on the plane, and there is a certain extension, which often reflects the fault zone or contact zone The distribution of magnetic anomaly is linear or beaded, or the negative anomaly of geomagnetic and aeromagnetic is linear, so it can be inferred that there are fault zones (3) the magnetic anomaly is obviously dislocated along the strike, which is often the reflection of transverse fracture The gravity high anomaly with a certain strike length often corresponds to positive structural units, such as anticline or rock mass uplift, while the gravity low anomaly corresponds to negative structural units, such as syncline sag, etc If the isolines of frequency sounding are vertical or inclined, the anomalies are often caused by faults The linear magnetic anomaly is caused by the intrusive magnetic rock mass in the fault, and the isolated magnetic anomaly is caused by the rock mass if the gradient is slow in the middle and steep at the edge, and there is a certain intensity of apparent magnetization anomaly The magnetic anomalies are chaotic in a large range, with positive and negative anomalies, and their field values are different. If the anomalies disappear after upward digital processing, the anomalies are caused by volcanic rocks; If the anomaly does not disappear, but its shape becomes regular and the gradient becomes smooth, the anomaly is caused by rock mass There are local anomalies with ring distribution and trend change at the edge of a large and low magnetic anomaly, corresponding to the contact zone between rock mass and surrounding rock The remote sensing images of rings, chains or rings can indicate volcanic institutions and ore deposits in groups (3) geochemical prospecting criteriathe geochemical work in Ning Wu area is of little significance to iron ore prospecting, so there is no systematic geochemical exploration work, only sporadic 1 ∶ 10000 geochemical exploration has been carried out in Danbo area in the eastern part of Ma'an, with local Cu and Au anomalies
(4) main exploration methods: firstly, through 1 ∶ 10000-1 ∶ 2000 geological survey, the distribution and characteristics of strata, structures and magmatic rocks in the area, the relationship between them, and the relationship with mineralization are comprehensively and systematically investigated, and the metallogenic conditions and characteristics are further understood through stratigraphy, petrology, mineralogy, tectonics, etc, The evaluation of prospecting prospect provides scientific basis for further workon the basis of aerial survey, we carried out 1 ∶ 10000-1 ∶ 5000 high-precision magnetic survey scanning to determine the abnormal shape and distribution range, which provided the basis for the layout of exploration engineering. With the gravity measurement of contract scale magnetic survey, gravity and magnetic synchronization, it provides sufficient scientific basis for further work. If the structure of the working area is complex and the ore body is deeply buried, electrical and magnetic profile survey and sounding should be done. Three component magnetoelectric logging is an effective method to discover deep lateral anomalies and ore bodies. In particular, it is better to carry out this work in every borehole for geophysical anomaly verification. We should strengthen the study of comprehensive techniques and methods for deep prospecting, including seismic, Cr, IP sounding and so on
drilling is not only the main means to search for concealed ore bodies, find out the shape and occurrence of ore bodies, but also an important method to verify various anomalies. With the deepening of a new round and deep prospecting, drilling technology is constantly updated and improved, and drilling becomes more and more important. Ningwu area covers a large area. It is absolutely impossible to make a breakthrough without drilling
(Zhao Yunjia, Gao Daoming, Hong Dongliang)
The iron ore-forming belt is located on the Kangdian axis and the western margin of the Yangtze platform. Its basement consists of "Kangding complex" (and its corresponding rock group) composed of amphibolite facies to granulite facies metamorphic rocks and granitic rocks from the end of Archean to Paleoproterozoic, and low metamorphic strata such as Kunyang group or Huili group from Mesoproterozoic to Neoproterozoic, And Neoproterozoic Jinningian granitoids. Sinian system and some Phanerozoic strata were deposited on it, which were obviously influenced by Paleozoic magmatic activities (mainly intrusive activities). This is an important metallogenic belt of inherited polycyclic iron deposits in the north-south direction. The proven iron ore reserves reach 7.07 billion tons, accounting for 13.7% of the total reserves in China
Table 2-8 characteristics of banded siliceous iron deposits in each group of strata of Anshan Group in AnBen area and its periphery Iron deposits, high-temperature gas-liquid metasomatic and filling iron deposits form a metallogenic series, and locally contain pulp type iron deposits, which are distributed in Dahongshan (Dahongshan Iron Deposit in Yunnan) and laachang, southwest of Huili, Sichuan, respectively (Fig. 2-12). In addition, similar iron deposits can be found in the middle Kunyang group and its corresponding low metamorphic strata in other places of Huili and e'touchang, northwest Kunming, Yunnan. Some may form large deposits. Secondly, there are Neoproterozoic iron deposits related to Jinning and Chengjiang magmatic activities. At that time, there were large-scale acidic volcanic eruptions and magmatic intrusions, mainly along the Anninghe fault with a small amount of basic rocks. In the intrusive contact zone and its vicinity, there are mainly contact metasomatic and hydrothermal metasomatic iron and tin deposits, forming the iron tin metallogenic belt in this area. The ore belt extends from xidechaowangping to the north of Xichang to Shiping to the south of Kunming. From north to south, there are granites and granodiorites related to iron tin mineralization, such as Lugu, moshaying, Shunhe and Changtang. The age of the Lugu granite is relatively new, with an isotopic age of 635-716 Ma, belonging to the Chengjiang period. The granites in moshaying and the south of spring are older, with isotopic ages ranging from 719 Ma to 1084 Ma, belonging to the Jinning period. In terms of associated mineralization, there are mainly contact metasomatic and hydrothermal metasomatic iron deposits or (TIN) iron deposits in the outer contact zone of Lugu granite. The moshaying and Shunhe plutons are mainly associated with contact metasomatic tin deposits, followed by hydrothermal metasomatic iron deposits. There are W-Sn-bearing hematite orebodies in the contact zone between Shiping Longtan granodiorite and biotite granite in Yunnan Province
Fig. 2-12 distribution of main iron ores in Xichang Central Yunnan area the basic and ultrabasic rock mass bearing vanadium titanium magnetite in Panxi area in the northern part of the belt is the most important ore-forming parent rock of iron deposits in this area, and there are some contradictions in the isotopic ages previously determined, Most of the ore bearing rocks are intruded into dolomitic marble of Upper Sinian or carbonate rocks of pre Sinian, and most of them are covered by Mesozoic strata. It seems that whether the main metallogenic age of the pluton belongs to the early or late Paleozoic, or both, remains to be confirmed by further work in the future. The related magmatic vanadium titanium magnetite deposits are the most important type of iron deposits in the area, which are concentrated in Mianning in the north, Jinsha river bank in the south, and along the west side of the Anning River fault. The ore belt is about 320km long. This kind of iron deposit also occurs in mouding, Yunnan, but its scale is far less than some deposits in Sichuan. The distribution of vanadium titanium magnetite deposits in this area can be further divided into two ore belts: the east ore belt is located in the narrow zone to the west of ANNINGHE FAULT and to the east of lvjiang fault, including Taihe, Badong, Baima, Baicao and Hongge, which is the main ore belt; The west ore belt is located in the west of the Lujiang fault, including Panhua, luoudi, Anyi and other mining areas (Fig. 2-12)
There are sedimentary iron deposits of different ages in the platform cover of Kangdian axis. They are distributed to the east of Anninghe Yimen deep fault. The Huatan iron deposit of Middle Ordovician and Bijishan and yuzidian iron deposits of Middle Devonian are more important There are Manyingou type sedimentary metamorphic iron rich deposits in shuangshuijing formation of Upper Proterozoic. The iron deposits are mainly distributed on the unconformity formed by the Manyingou movement. A set of clastic rocks are mainly composed of iron argillaceous cemented quartz clasts. Under this iron bearing rock series, metamorphic tuff and intermediate acid metavolcanic rocks are distributed on the unconformity. Therefore, it is suggested that the genesis of iron deposits may be related to volcano sedimentation (the first iron deposit research team, Institute of Geology and mineral resources, Chinese Academy of Geological Sciences, 1978) Iron ore deposits dominated by siderite are widely distributed in carbonate strata and volcanic sedimentary clastic rocks of the Mesoproterozoic fengshanying formation in Xichang area and Dalongkou formation of the Mesoproterozoic Kunyang group in Central Yunnan. The shape of ore body is stratoid, lenticular or vein. The mineral composition of ore is simple. The main mineral is siderite, followed by hematite. The gangue mineral is calcite, followed by quartz and chlorite. The representative deposits are fengshanying in Huili, Lukuishan in Xinping, Wangjiatan in Anning, etc. Cheng Institute of Geology and mineral resources (1986) has determined RB Sr isotopic ages of carbonate rocks and siderite in fengshanying formation. The results show that the former is 1540ma, while the latter is 534-846ma. It is considered that 1540ma represents the age of stratigraphic and primary sedimentary siderite, and 534-846ma reflects the hydrothermal mineralization age of this kind of deposit, indicating that the formation of siderite has experienced more than one mineralization stage1 Overview
the mining area is located 15km north to the east of LUANNAN COUNTY, 15km away from Luanxian east station of West Beijing mountain railway, under the jurisdiction of Macheng Town, LUANNAN COUNTY. During 1971-1977, a general survey was concted by team 514 (later changed to team 515) of North China Metallurgical Geological Exploration Company. A total of 19848m (34 boreholes) were drilled and 1228 samples were basically analyzed. In December 2003, Qinhuang branch of the first Exploration Institute of General Administration of geology of MCC (reformed from team 515) compiled the geological survey report, and the 333 + 334 resource amount was 79213.2 × 10 < sup > 4 < / sup > t, of which 333 resources in the mineral resources reserve table of upper Hebei Province is 42132.7 × 104t
the mining area is completely covered by quaternary system, and the terrain is flat. The terrain is generally higher in the north and lower in the south, and slightly higher in the West than in the East. The surface elevation is 15-20m, and the relative elevation difference is 3-5M
(2) metallogenic geological conditions1. Stratum
the stratum of the mining area is simple, with double-layer structure, the surface layer is Quaternary sediments, and the basement is metamorphic rock series of Archean yuluanxian group
(1) the Archean yuluanxian group is the bedrock part of the mining area and also the ore bearing horizon. It is a set of metamorphic rocks with shallow metamorphism (amphibolite facies) and fine grain size. The main lithology is biotite granulite, amphibolite, hornblende plagioclase gneiss and magnetite quartzite. The rocks are subjected to migmatization in different degrees, and gneissic migmatite and migmatite are formed in the strong section (2) the thickness of Quaternary System in Cenozoic is generally 90-180m and 60-80m in the thin part, and the thickness graally increases from north to south, and the thickness in the west is slightly larger than that in the East. Generally, the lithology exposed on the surface is mainly clayey sand, under which are sand, sand gravel, clay, etc The mining area is located in the southwest of Yanshan platform fold belt (II) Shanhaiguan platform arch (III), east of Qinglonghe fault and East Wing of Sima compound syncline. Regionally, although the folds in this area are quite complex, the drilling engineering and magnetic survey results show that the strata and ore bodies in the mining area are monoclinic structure, with the general strike of NNW and local swing of NE or NW; It is generally inclined to the West with an inclination of 30 °～ fifty °， It is steeper in shallow part and slower in deep part. According to the existing engineering control, there is no fault structure with a certain scale in the mining area Magmatic rocksaccording to the drilling project, the magmatic rocks in the mining area are not developed, no large intrusive rocks are found, only small-scale medium basic dikes are found, and the main lithology is diorite porphyrite, mostly bedding
According to the general survey report in 2003, the orebodies are distributed in the range of 5.5km in length from north to south, 1-2km in width from east to west and 10km in area. There are six orebodies in two large ore belts in the north and south of the mining area. There are five orebodies in the south of the mining area, numbered I-V; There is one ore body in the North ore belt, No. VI. According to its scale, II ore body is the largest, followed by I ore body with length of 3300m and 3200m respectively; Other orebodies are 900-2700m in length. The northern end of ore bodies I and II pinches out between line 8-16, and the southern end is in the south of line 39. The strike and plane shape of the ore body are basically consistent with the trend of the magnetic anomaly curve, which is similar to the "s" shape on the plane. There are more ore beds in the area with enlarged magnetic anomaly, and the thickness of the ore body is large. There are fewer ore beds in the contraction area, and the thickness of the ore body is thin, especially in the II ore body (Fig. 4-12)
Fig. 4-12 ore body distribution diagram of Macheng iron mine in LUANNAN COUNTY. The thickness of the ore body varies greatly, with obvious expansion and contraction and branching. The ore body is basically composed of 2-6 layers of ore, which is actually a ore belt. The thickness of single layer ore is from several meters to tens of meters, and the thickest is more than 90m (23 line ck96 hole I ore body) (Fig. 4-13); The thickness of ore belt (including rock inclusion, the same below) ranges from more than ten meters to more than 150 meters (line 39 II ore body) (Fig. 4-14, (Fig. 4-15)
The depth of Macheng iron ore body is large. In the past, the drilling engineering mainly controlled the I and II ore bodies, with a general depth of 700-1100m and no pinch out potential. Therefore, the depth of each ore body has a great prospectaccording to the general survey report, I and II ore bodies account for 95.7% of 333 resources, of which II ore body accounts for 75.7%; It accounts for 67.70% of the total amount of 333 + 334, of which the II ore body accounts for 53.30%. See table 4-8 for resources of each ore body
Fig. 4-13 profile map of 23 exploration line of Macheng iron mine in LUANNAN COUNTY
Fig. 4-14 profile map of 39 exploration line of Macheng iron mine in LUANNAN COUNTY
< P >
Fig. 4-15 profile map of 0 exploration line of Macheng iron mine in LUANNAN COUNTY
Table 4-8 resource quantity statistics of each ore body in 2003 census report The ore is magnetite (hematite) quartzite with simple mineral composition. The ore minerals are mainly magnetite or pseudo hematite with a small amount of hematite; Gangue minerals are mainly quartz, followed by FE Mg amphibole, a small amount of hornblende, tremolite and so on
the ore is mostly of fine-grained meta crystalline structure, and the particle size is slightly larger than that of Sijiaying Iron ore. The ore structure is mainly stripe and strip structure, and a small amount is dense massive and gneissic structure. Dense massive structure is also the feature of rich iron ore
(2) ore type and grade
ore type: according to the main iron ore, magnetite accounts for 96% of the total resources, hematite only accounts for 4%; According to the main gangue minerals in the ore, they are all quartz type iron ore. The instrial type of ore belongs to the iron ore (lean ore) to be beneficiated, and the vast majority of them are magnetic iron ore
ore grade: the ore grade (TFE) is relatively uniform. According to the statistics of 1171 samples involved in resource estimation in the census report, 80% of the samples have a grade greater than 30%, of which 54% have a grade of 30% ～ 40% and 26% have a grade ≥ 40%. The average grade (TFE) of the whole area is 34.70%, including magnetite grade of 34.69% and hematite grade of 34.93%. Generally speaking, the grade of ore body changes little along strike and dip direction, and there is no regular change of systematic increase or decrease. According to the statistics of ore belt, the grade of South ore belt is obviously higher than that of North ore belt; According to the statistics of ore body, the highest grade of ore body I is 36.16%, and the lowest grade of ore body III is 30.58%; According to the statistics of ore types, hematite is slightly higher than magnetite. The ore body grades are shown in table 4-8. Although the highest grade TFE can reach 52.33%, it has no separate mining value
(3) ore oxidation degree
according to the control of drilling engineering, the ore oxidation degree is relatively low, hematite ore is mainly seen in indivial boreholes of II ore body, and the thickness is not large. It is mainly distributed in the section 40-60m below the bedrock surface, with the lowest elevation ranging from - 90 to - 100m
(4) ore chemical composition and washability
ore chemical composition is mainly Si, Fe and o. The average content of SiO < sub > 2 < / sub > in ore is 48.35%, and the relationship between SiO < sub > 2 < / sub > and TFE is increasing and decreasing. The average mass fraction of S and P is 0.21% and 0.057%, respectively. The content of titanium, manganese and alum in the ore is very low, so it has no comprehensive utilization value. In view of the fact that the particle size of the ore is larger than that of the nearby Sijiaying Iron ore, it is predicted that the ore beneficiation effect will be better than that of Sijiaying Iron ore. in particular, most of the ore is magnetite, so it is easy to process and beneficiate
The anomaly is located 5km to the east of Sijiaying Iron Ore Area in Luanxian LUANNAN magnetic anomaly area. The anomaly is a nearly north-south zonal anomaly with a length of 4000m and a width of 1500-1800m. The northern end of the anomaly is NNW, the whole anomaly length is about 6000 m, the peak value of the anomaly is nearly 2000 NT, and the scale of the anomaly is large. According to the analysis of anomaly morphology, the mineral resource centers are distributed near the south of the anomaly (5) the hydrogeological unit where the mining area is located is basically similar to the south area of Sijiaying Iron Mine. Due to the complex hydrogeological conditions, the Quaternary aquifer is thick and rich in water; In addition, the mining area is adjacent to Luanhe River in the East, so the future mining is only suitable for underground mining. At present, the degree of hydrogeological work in the mining area is low, no special hydrogeological work has been done, and the mining technical conditions of the deposit need to be further identified. In particular, the fourth aquifuge, bedrock hydrogeological characteristics and water content will directly affect the future development and utilization of the mine (VI) exploration type and instrial index1. Exploration type of ore deposit
the strike length of Macheng iron ore body is generally more than 1000m, the dip extension is more than 500m, and the continuous distribution area is more than 1km < sup > 2 < / sup >, which belongs to large iron deposit. The orebody is bedded and lenticular with intercalated rocks. It has obvious expansion and contraction branching complex phenomenon along the strike and dip, and the orebody shape is complex. The occurrence of ore body is stable, monoclinic, undeveloped fault structure and simple deposit structure. The useful components of the ore are evenly distributed and the grade is stable. In conclusion, the deposit is classified as type II exploration. The exploration project spacing is: 332, the resource volume is 200m ~ 250m × 200m 333 400 m resource × 200m～400m × 400m
In view of the fact that Macheng iron mine and Sijiaying Iron Mine belong to the same sedimentary metamorphic iron deposit, and they are relatively close to each other, and the metallogenic geological conditions are similar, the instrial index of Sijiaying Iron Mine is used as the general instrial index According to the geological characteristics of the mining area and ore body, Macheng iron deposit belongs to metamorphic ferrosilicon formation iron deposit, also known as Anshan type iron depositthe deposit is the main deposit in the south of qianluan iron ore metallogenic belt, with a large range of magnetic anomalies, a large number of orebodies and a large scale, especially the length of I and II orebodies has reached more than 3000 m, the thickness of some orebodies can reach more than 100 m, and the extension depth can reach more than 1000 m. The prospecting work in 2008 showed good results. It is estimated that the resource reserves reach 10 × More than 10 < sup > 8 < / sup > t
000655 Jinling mining, iron ore lead, will switch to 000655 Jinling mining, the main proct of iron concentrate. At present, the company is the only "pure iron ore resource-based listed company" in China. According to the company's public information, the recoverable reserves of the injected ore are expected to be three times of the current iron ore assets, and the output is similar. On the whole, compared with other iron mines in China, Jinling iron mine is rich, but objectively speaking, the overall scale is small<
in 2004, Antai group (600408) obtained the prospecting right of shenyangou iron mine in Lianggou Town, Yuanping City, Shanxi Province. After more than one year's exploration organized by Antai mining, the holding subsidiary of the company, the proven iron ore reserves were 15.97 million tons, and the iron ore mining license issued by the Department of land and resources of Shanxi Province was obtained in February 2006, This will enable the company to obtain a stable supply of iron ore raw materials, not only to further rece the proction cost of pig iron, but also to grasp the ore resources which can be called the lifeline of the instry! At present, there is only one large enterprise in China's coke instry, Antai group, which has obvious monopoly advantage. The company is mainly engaged in coal washing, coke proction and sales, the main procts metallurgical coke, pig iron export to the United States, Japan, South Korea and other international markets<
000762 Tibet Mining: it is mainly engaged in the mining, proction and processing of chromite, mainly in the mining, processing and sales of chromium, copper and lithium. It has the franchise and franchise of resource mining, and has obvious resource advantages, so it is in a monopoly position. The company is rich in mineral resources. Chromite is the shortage mineral in China. The annual domestic demand is 1.5-1.8 million tons, while the national proction is only about 300000 tons. Tibet is rich in chromite resources with high quality, and its reserves rank first in the country. The company is also the first "copper hydrometallurgy" enterprise in Tibet. In addition, the company actively develops lithium resources. The first phase of the instrialization demonstration project of resource development in Zabuye Salt Lake in Tibet, which is the holding subsidiary of the company, has passed the acceptance and will play a great role in improving the company's performance. Zabuye Salt Lake in Tibet is one of the three largest lithium salt lakes in the world. After the completion of the second phase project, the proction capacity of lithium salt procts will be greatly improved< According to the introction, in terms of mineral resources development, Xining Special Steel has controlled the iron ore resources and coal resources, and the next step is to speed up the development and construction. The company has established Xisteel Mining Development Co., Ltd., which will develop three iron ores in Qinghai Province in the future. Among them, the preliminary geological reserves of Dashuang iron mine are 32 million tons, that of magnetite mountain iron mine is 35 million tons, and that of Hongshuihe iron mine is 12.1 million tons. It is planned to be completed and put into operation in three years, forming a proction capacity of 700000 tons. According to instry insiders, the price of iron concentrate has risen from 400 yuan / ton to 500 yuan / ton, and it is very likely that the price of iron concentrate will continue to rise in 2008 e to the sharp increase of iron ore price by Australian iron ore giants<
600083 * ST Boxin: * the deflection line circle of St Boxin has been completely stripped, and its main business has turned to non-ferrous metal mining. Ding Boxin, who is determined to go to the mine, has successively discussed restructuring with Yunnan Copper Group and Yunnan Longxin mining, but they all failed* Due to the company's financial difficulties, St Boxin failed to fulfill its repayment obligations within the time limit specified in the legal documents. Cheng Intermediate People's court will enforce it in accordance with the law, which will lead to the judicial auction of 37.5% of the equity of Shaanxi Lianshi Mining Co., Ltd. held by the company.