Interlayer-containing steeply inclined thick and large phosphate rock layer mining sequence determination method

Abstract

The invention belongs to the field of phosphorite bed mining design, and particularly relates to an interlayer-containing steeply inclined thick and large phosphorite bed mining sequence determining method which comprises the steps that the comprehensive strength index of each stratum is obtained based on the stratum thickness and strength, and the single blasting thickness is selected as the ore bed thickness; if Kj is minimum, the ore bed b is mined firstly, and filling is conducted after an interlayer is blasted; mining an ore bed a and filling; if the Ka is minimum, the ore bed a is firstly mined and filled, and then the ore bed b is mined and filled; if Kb is minimum, firstly mining the ore bed b, blasting the interlayer when Ka is stronger than Kj, and filling; and mining and filling the ore bed a. According to the method, the strength of the two ore beds, the interlayer and the top plate can be compared by establishing the comprehensive strength index, the comprehensive strength index is particularly suitable for guiding the mining sequence and the mining direction of the ore beds and selection of interlayer removal, and mining safety can be guaranteed to the maximum extent.

Description

Technical Field

[0001] The invention belongs to the field of phosphate deposit mining design, and in particular relates to a method for determining the mining sequence of a steeply inclined thick phosphate ore layer containing an interlayer. Background Art

[0002] The Weng'an Daxin Beidoushan Phosphate Mine is rich in two layers of ore, a and b. The ore body has a total length of 190m, a tilted extension of 240m, and a deep ore body with a dip angle of 55° to 70°, forming a steeply inclined ore layer. Both a and b ore layers are thick and large ore bodies; there is an obvious interlayer between a and b ore layers, which is mainly composed of phosphorus dolomite and phosphorus-containing carbonaceous mudstone, with an average thickness of 3.83m. Due to the small thickness of the interlayer, that is, the distance between a and b ore layers is very small, so a and b ore layers are mined simultaneously, specifically using the upward segmented open pit and subsequent filling mining method.

[0003] At present, the mine has mined the middle section of 1020 and the middle section of 1080, all of which are mined by retaining the interlayer and mining the a ore layer first and then the b ore layer. However, if the interlayer is thin and weak, the interlayer is easy to break, which will affect the safe mining of the ore layer, especially when mining the a ore layer first from the interlayer to the floor side. In addition, the strength and thickness of the top and bottom plates of the ore layer will also affect the safe mining of the ore layer.

[0004] Therefore, affected by the changes in interlayer thickness and strength, how to deal with the interlayer (such as retention or blasting), and how to simultaneously consider the strength of the roof and floor plates to determine the mining sequence and direction of the a and b ore layers to maximize mining safety remain to be solved. Summary of the invention

[0005] In order to solve the above technical problems, the present invention proposes a method for determining the mining sequence of a steeply inclined thick phosphate ore layer containing an interlayer, comprising the following steps:

[0006] S1: Based on the thickness and strength of the stratum, the comprehensive strength index K of the roof and interlayer is obtained respectively. d , K j ; Based on the thickness and strength of the single blasting of the ore layer, the comprehensive strength index K of the b ore layer and the a ore layer is obtained respectively b , K a ;

[0007] S2: Comparison K a , K b , K j ;

[0008] S3: If K j The minimum is to first mine the b ore layer and transport it out; blast the interlayer and do not transport it out, and use filling materials mixed with the interlayer crushed rocks from the blasting to fill the b ore layer and the empty area created by the mining of the interlayer; mine the a ore layer and transport it out, and use filling materials to fill it in later;

[0009] S4: If K a Minimum; mining a ore layer, transporting it out, and filling it with filling materials; mining b ore layer and transporting it out, and filling it with filling materials;

[0010] S5: If K b The smallest, first mine the b ore layer;

[0011] S51: If K j Stronger than K a ; mining the b ore layer and transporting it out, and then filling it with filling materials; mining the a ore layer and transporting it out, and then filling it with filling materials;

[0012] S52: If K a Stronger than K j ; First, mine the b ore layer and transport it out; blast the interlayer and do not transport it out, and use filling materials mixed with the interlayer crushed stone from the blasting to subsequently fill the b ore layer and the empty area caused by the mining of the interlayer; mine the a ore layer and transport it out, and use filling materials to fill it later.

[0013] Preferably, in step S1, the comprehensive strength index is determined by the product of thickness and strength.

[0014] Preferably, in step S1, the strength is selected as a uniaxial compressive strength index.

[0015] Preferably, in steps S3, S4, S51, and S52, if K d K greater than a certain multiple b , mine the b ore layer from top to bottom, otherwise mine the b ore layer from bottom to top.

[0016] Preferably, in steps S3, S4, S51 and S52, the filling material is a cementitious filling material.

[0017] Preferably, in steps S3 and S52, the a ore layer is mined from top to bottom.

[0018] Preferably, in steps S4 and S51, the a ore layer is mined from bottom to top.

[0019] Preferably, the ore layer is mined using a staged open stop and subsequent fill mining method.

[0020] Preferably, the ore layer is mined using an upward staged clear stop and subsequent fill mining method.

[0021] Beneficial technical effects: The present invention can compare the strength of two ore layers, an interlayer and a roof by establishing a comprehensive strength index. This comprehensive strength index is particularly suitable for guiding the mining sequence and mining direction of the ore layers and the selection of whether to retain or remove the interlayer. The present invention can ensure mining safety to the greatest extent. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 It is a schematic diagram of the inclined cross section of the occurrence of the phosphate ore layer of the present invention;

[0023] Figure 2 It is a schematic diagram of the inclined section of the upward segmented open pit and subsequent filling mining method;

[0024] Figure 3 It is a schematic diagram of the strike profile of the upward segmented open pit and subsequent filling mining method;

[0025] In the figure, a-ore layer; b-ore layer; interlayer 1, roof 2, bottom plate 3, first section 41, second section 42, third section 43, middle transport lane 5, segmented transport lane 6, rock drilling lane 7, blasting hole 8, first step mine room 91, second step mine room 92. DETAILED DESCRIPTION

[0026] The following is an example of the Weng'an Daxin Beidoushan Phosphate Mine. Figure 1-3 , the present invention is further described.

[0027] like Figure 1-3 As shown in the figure, the Weng'an Daxin Beidoushan Phosphate Mine is rich in two layers of a and b, which are steeply inclined layers. The total length of the ore body is 190m, and the inclined depth is 240m. There is an obvious interlayer 1 between the a and b layers, which is mainly composed of phosphorus dolomite and phosphorus-containing carbonaceous mudstone, with an average thickness of 3.83m. Since the thickness of interlayer 1 is small, that is, the distance between the a and b layers is very small, the a and b layers are mined at the same time, and the specific mining method is the upward segmented empty field followed by filling. However, if the thickness of interlayer 1 is thin and the strength is small, interlayer 1 is easy to break and affects the safe mining of the ore layer, especially when the a ore layer is mined first from the interlayer 1 to the bottom plate 3. In addition, the strength and thickness of the roof 2 and the bottom plate 3 will also affect the safe mining of the ore layer.

[0028] Therefore, affected by the changes in the thickness and strength of interlayer 1, how to deal with interlayer 1 (such as retention or blasting), and how to simultaneously consider the strength of roof 2 and floor 3 to determine the mining sequence and mining direction of a and b ore layers to maximize mining safety remain to be solved.

[0029] Before introducing the specific technical solution of the present invention, the upward segmented empty field and subsequent filling mining method is briefly introduced (this technology is the prior art, and is only briefly introduced in this article without further elaboration); Figure 1-3As shown, for a certain middle section, its vertical height is 45m, and the middle section is divided into three sections along the height direction, namely the first section 41, the second section 42, and the third section 43 from bottom to top. The mining thickness designed in the middle section includes the entire thickness of the a ore layer and the b ore layer; at the same level at the lower part of each section, a segmented transport tunnel 6 is constructed along the strike on the outer side of the roof 2 and the outer side of the bottom plate 3, and at the same level at the upper part of the third section 43, a segmented transport tunnel 6 is constructed along the strike on the outer side of the roof 2 and the outer side of the bottom plate 3. The segmented transport lane 6 also serves as the transport lane of the entire middle section, and can also be called the middle transport lane 5; for each segment, it is divided into several mine rooms along the strike, and the width of each mine room is about 15m; for each mine room, a rock drilling and mining lane 7 is horizontally constructed through the ore layer at the lower part thereof to connect the segmented transport lane 6 at the corresponding position of the outer side of the roof 2 and the outer side of the bottom plate 3, and for each mine room of the third segment 43, a rock drilling and mining lane 7 is horizontally constructed through the ore layer at the upper part thereof to connect the segmented transport lane 6 at the corresponding position of the outer side of the roof 2 and the outer side of the bottom plate 3;

[0030] The three sections are mined and filled in sequence from bottom to top, and the method for mining and filling each section is as follows: a mine room is selected, and a plurality of rows of fan-shaped blasting holes 8 are constructed along the thickness direction of the ore layer from the rock drilling and mining tunnel 7 at the upper part thereof, and one row is blasted each time. The ore after blasting is transported from the rock drilling and mining tunnel 7 at the lower part of the mine room to the segment transportation tunnel 6. When the ore in the entire thickness direction of the mine room is mined (or when the ore in the entire thickness direction of one layer of the ore layer is mined), the empty area caused by mining the mine is filled.

[0031] In addition, each segmented mine room can be alternately divided into a one-step mine room 91 and a two-step mine room 92 along the direction. The one-step mine room 91 is mined and filled first, and then the two-step mine room 92 is mined and filled. This is a mining method well known in the art and will not be repeated here.

[0032] The downward segmented empty-stop and subsequent filling mining method mines each segment in the middle section from top to bottom, and its mining method is consistent with the upward segmented empty-stop and subsequent filling mining method.

[0033] In response to the above problems, Figure 1-3 As shown, based on the segmented empty field and subsequent filling mining method, especially based on the upward segmented empty field and subsequent filling mining method, the present invention proposes a method for determining the mining sequence of a steeply inclined thick phosphate ore layer containing an interlayer, which is particularly suitable for steeply inclined ore layers, comprising the following steps:

[0034] S1: Obtain the comprehensive strength index of adjacent strata, the adjacent strata include the roof 2, the b ore layer, the interlayer 1, the a ore layer and the bottom plate 3 from top to bottom, the comprehensive strength index refers to an index that can reflect the thickness and strength of the strata; for the strata other than the a ore layer and the b ore layer, such as the roof 2, the interlayer 1 and the bottom plate 3, the comprehensive strength index is obtained by the product of the thickness of the strata and the stratum strength index (such as uniaxial compressive strength); for the a ore layer and the b ore layer, the comprehensive strength index is obtained by the product of the single blasting thickness of the ore layer and its stratum strength index (such as uniaxial compressive strength), for example, several rows of fan-shaped blasting holes 8 will be constructed along the thickness direction of the ore layer for blasting and dropping, and the thickness of the ore layer that can be blasted by one or several rows of blasting holes blasted at the same time is taken to calculate the comprehensive strength index of the a ore layer and the b ore layer;

[0035] S2: Compare the comprehensive strength indexes of the a ore layer, b ore layer and interlayer 1;

[0036] S3: If the comprehensive strength index K of interlayer 1 j Minimum;

[0037] S31: The b ore layer is located on the side of the relative roof of the interlayer 1, slightly on the upper side, so the b ore layer is mined first. After the b ore layer is mined, the interlayer 1 will not be suspended in the air, and there is no risk of collapse. At most, it will partially fall off. If the a ore layer is mined first, since the interlayer 1 is located on the side of the relative roof of the a ore layer, after the a ore layer is mined, the bottom plate side of the interlayer 1 has no support and is in a suspended state, which is easy to collapse, which has a safety impact on the mining of the a ore layer, and the comprehensive strength index K of the a ore layer is a Greater than the comprehensive strength index K of the interlayer j , the energy required for mining can also easily destroy interlayer 1;

[0038] Furthermore, if the comprehensive strength index K of the top plate 2 is d Greater than 1.5 times the comprehensive strength index K of the b ore layer b , mine the b ore layer from the roof 2 to the bottom 3 and transport it out, otherwise mine the b ore layer from the bottom 3 to the roof 2 and transport it out; blast the interlayer 1 and do not transport it out, and use cemented filling materials mixed with the interlayer crushed stones from the blasting to fill the empty areas created by the mining of the b ore layer and the interlayer 1; the comprehensive strength index K of the roof 2 d Greater than the comprehensive strength index K of the b ore layer b When mining the b ore layer, the disturbance caused by mining the b ore layer is small. It is preferred to consider mining the b ore layer from the roof 2 to the bottom plate 3. Since the roof 2 is located on the roof side of the b ore layer, the roof 2 is suspended in the air after the mining of the b ore layer, and it is easy to be affected by its own weight to produce bending deformation or even damage. Therefore, a certain safety factor is taken. For example, in this embodiment, 1.5 times the roof comprehensive strength index K d and b ore layer comprehensive strength index K b Compare;

[0039] S32: At this time, for the a ore layer, the subsequent filling body of the b ore layer and the interlayer has a large comprehensive strength index due to its large thickness, and there is no need to consider the comprehensive strength index of the bottom plate 3. The a ore layer can be mined from the top plate 2 to the bottom plate 3 and transported out, and cemented filling materials are used for subsequent filling;

[0040] S4: If the comprehensive strength index K of the a ore layer a Minimum;

[0041] S41: mining the a ore layer from the bottom plate 3 to the top plate 1, transporting it out, and filling it with cemented filling materials later; mining the a ore layer from the bottom plate 3 to the top plate 1 can reduce the suspended exposure time of the interlayer 1, reduce the danger of mining the a ore layer, and is also conducive to the later mining of the b ore layer; even if the comprehensive strength index of the bottom plate 3 is weaker than that of the a ore layer, since it is located at the relative bottom side of the a ore layer, it will not be exposed, and the danger is very low;

[0042] S42: mining of the b ore layer, at which time interlayer 1 has no risk of collapse;

[0043] If the comprehensive strength index K of the top plate 2 d Greater than 1.5 times the comprehensive strength index K of the b ore layer b , mine the b ore layer from the roof 2 to the bottom 3 and transport it out, otherwise mine the b ore layer from the bottom 3 to the roof 2 and transport it out; use cemented filling materials for subsequent filling; the comprehensive strength index K of the roof 2 d Greater than b ore layer comprehensive strength index K b When mining the b ore layer, the disturbance caused by mining the b ore layer is small. It is preferred to consider mining the b ore layer from the roof 2 to the bottom plate 3. Since the roof 2 is located on the side of the b ore layer relative to the roof, the roof 2 is suspended in the air after the mining of the b ore layer, and it is easy to bend and deform or even be damaged by its own weight. Therefore, a certain safety factor is taken, that is, 1.5 times the roof comprehensive strength index K is required. d and b ore layer comprehensive strength index K b Compare;

[0044] S5: If the comprehensive strength index K of the b ore layer b The smallest; first mine the b ore layer;

[0045] S51: If the comprehensive strength index K of interlayer 1 j Stronger than the comprehensive strength index K of the a ore layer a ;

[0046] S511: If the comprehensive strength index K of the top plate 2 d Greater than 1.5 times the comprehensive strength index K of the b ore layer b , the b ore layer is mined from the top plate 2 to the bottom plate 3 and transported out, otherwise the b ore layer is mined from the bottom plate 3 to the top plate 2 and transported out; cemented filling materials are used for subsequent filling; the reasons for the selection of the mining direction are the same as those of S42;

[0047] S512: mining the a ore layer from the bottom plate 3 to the top plate 1, transporting it out, and filling it with cemented filling materials later; mining the a ore layer from the bottom plate 3 to the top plate 1 can reduce the suspended exposure time of the interlayer 1, reduce the danger of mining the a ore layer, and is also conducive to the later mining of the b ore layer; even if the comprehensive strength index of the bottom plate 3 is weaker than that of the a ore layer, since it is located at the bottom side of the a ore layer, it will not be exposed, and the danger is very low;

[0048] S52: If the comprehensive strength index K of the a ore layer a Stronger than the comprehensive strength index K of interlayer 1 j ;

[0049] S521: If the comprehensive strength index K of the top plate 2 d Greater than 1.5 times the comprehensive strength index K of the b ore layer b , mine the b ore layer from the top plate 2 to the bottom plate 3 and transport it out, otherwise mine the b ore layer from the bottom plate 3 to the top plate 2 and transport it out; blast the interlayer 1 and do not transport it out, and use cemented filling materials mixed with the interlayer crushed stones blasted to fill the empty area produced by the mining of the b ore layer and the interlayer 1; before mining the a ore layer, first mine (treat) the interlayer 1 whose comprehensive strength index is weaker than that of the a ore layer, to prevent the collapse of the interlayer 1 during the mining of the a ore layer, which will have a safety impact on the mining of the a ore layer; specifically, since the interlayer 1 is located on the side of the roof of the a ore layer, after the mining of the a ore layer, the bottom plate side of the interlayer 1 has no support and is in a suspended state, which is easy to collapse, which will have a safety impact on the mining of the a ore layer, and the comprehensive strength index of the a ore layer K a Greater than the comprehensive strength index K of the interlayer j , the energy required for mining can also easily destroy interlayer 1;

[0050] S522: At this time, for the a ore layer, the subsequent filling bodies of the b ore layer and the interlayer 1 have a large comprehensive strength index due to their large thickness. There is no need to consider the comprehensive strength index of the bottom plate 3. The a ore layer can be mined and transported from the top plate 2 to the bottom plate 3, and cemented filling materials can be used for subsequent filling.

[0051] The present invention is not limited to the above-mentioned optimal implementation mode. Anyone can derive other various forms of methods under the inspiration of the present invention. Any technical solution that is the same or similar to that of the present application falls within the protection scope of the present invention.

Claims

1. A method for determining the mining sequence of a steeply inclined thick phosphate ore layer containing interlayers, characterized in that: The steps include: S1: Based on the thickness and strength of the stratum, the comprehensive strength index K of the roof and interlayer is obtained respectively. d , K j ; Based on the thickness and strength of the single blasting of the ore layer, the comprehensive strength index K of the b ore layer and the a ore layer is obtained respectively b , K a ; S2: Comparison K a , K b , K j ; S3: If K j The minimum is to first mine the b ore layer and transport it out; blast the interlayer and do not transport it out, and use filling materials mixed with the interlayer crushed rocks from the blasting to fill the b ore layer and the empty area created by the mining of the interlayer; mine the a ore layer and transport it out, and use filling materials to fill it in later; S4: If K a Minimum; mining the a ore layer from bottom to top, transporting it out, and filling it with filling materials; mining the b ore layer and transporting it out, and filling it with filling materials; S5: If K b The smallest, first mine the b ore layer; S51: If K j Stronger than K a ; mining the b ore layer and transporting it out, and then filling it with filling materials; mining the a ore layer from bottom to top and transporting it out, and then filling it with filling materials; S52: If K a Stronger than K j ; First, mine the b ore layer and transport it out; blast the interlayer and do not transport it out, and use filling materials mixed with the interlayer crushed stone from the blasting to subsequently fill the b ore layer and the empty area caused by the mining of the interlayer; mine the a ore layer and transport it out, and use filling materials to fill it later.

2. The method for determining the sequence according to claim 1, characterized in that: In step S1, the comprehensive strength index is determined by the product of thickness and strength.

3. The method for determining the sequence according to claim 2, characterized in that: In step S1, the strength is selected as a uniaxial compressive strength index.

4. The method for determining the sequence according to claim 1, characterized in that: In steps S3, S4, S51, and S52, if K d K greater than a certain multiple b , mine the b ore layer from top to bottom, otherwise mine the b ore layer from bottom to top.

5. The method for determining the sequence according to claim 4, characterized in that: In steps S3, S4, S51 and S52, the filling material is a cementing filling material.

6. The method for determining the sequence according to claim 5, characterized in that: In steps S3 and S52, the a ore layer is mined from top to bottom.

7. The method for determining the sequence according to claim 6, characterized in that: In steps S4 and S51, the a ore layer is mined from bottom to top.

8. The method for determining the sequence according to any one of claims 1 to 7, characterized in that: The ore layer is mined using the segmented open stop followed by filling mining method.

9. The method for determining the sequence according to any one of claims 1 to 7, characterized in that: The ore layer is mined by the upward staged open stop and subsequent filling mining method.

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