Method for developing solid potash salt deposits

Abstract

The application discloses a solid potash salt mine development method, comprising the following steps: step 1, diverting surface runoff in a delineated mine area to lead the surface runoff from a source to an area far away from the potash salt mine area; step 2, after a new river channel is formed by the surface runoff diversion in step 1, performing geophysical exploration to determine an underground water enrichment area, arranging hydrological holes according to a specification, and determining parameters of the underground water; step 3, drilling at the edge of the mine area according to the parameters of the underground water obtained in step 2 to determine stratum distribution; and step 4, sealing various drill holes in a mining area in the mine area according to a specification, arranging grouting holes according to the water volume distribution of the hydrological holes, and performing grouting. The application eliminates water disasters of the solid potash salt mine from the source, and greatly reduces the geological disaster risks such as underground water leakage and collapse of a mine roof.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of mineral mining, in particular to a solid potash mine development method. BACKGROUND

[0002] Potash is mainly used for the manufacture of potash fertilizer. The main products are potassium chloride and potassium sulfate, which is one of the three indispensable fertilizers in agriculture. China is a country with extremely scarce potash resources. As an agricultural power, potash resources are a strategic resource that plays an important role in China's economic development. However, due to the scarcity of potash resources in China, the industry has lagged behind, and the supply of potash fertilizer has long relied on imports.

[0003] Food is the basis for the stable development of China's society and economy, and potash is the "food" for producing food. China's potash reserves are limited. We reserve less than 2% of the world's resources, and we use a nearly predatory mining method. Although it maintains nearly 15% of the world's production capacity, it still cannot meet the consumption demand of nearly 23% of the Chinese market. China's potash fertilizer will long rely on imports.

[0004] Although the Chinese Academy of Sciences provides technical support to solve a series of key problems in the exploration and development of potash, there are still many problems in the development of potash. The current underground mining of potash mainly faces two problems. First, surface fresh water flows into the underground through various channels, causing the dissolution of the ore bed, or groundwater forms a dominant channel into the ore bed, dissolving salt minerals and causing the risk of mine flooding and closure. Second, the problem of potash tailings and old brine. The main factors of potash water inflow are: (1) stratum, the special feature of salt deposit is that the solubility is large, and it is easy to dissolve when encountering fresh water, so there is a very thick water-resisting layer on the top of the main ore bed. The roof of the ore bed is mainly composed of mudstone and gypsum rock section. The mudstone and gypsum layer is a micro-aquifer, and the upper quaternary system is the main water layer. (2) Drilling, geological exploration requires drilling, and poor drilling sealing quality will form a water-conducting channel that reaches the ore bed, which brings serious hidden dangers to the water inflow in the underground. (3) Well and roadway engineering, the main development well bore engineering must pass through the roof rock to reach the ore bed, which directly connects the surface and the ore bed. Due to cost considerations, the quality of well bore construction cannot completely eliminate the water outflow from the back of the well bore. Generally, water interception measures are taken at the middle water outflow position to intercept the water, and strict water plugging measures are not taken due to cost considerations, resulting in a large part of the total mine water inflow being from the well bore. At present, the main development and transportation roadway is arranged in the ore vein. Due to the change of the ore body, part of the roadway roof penetrates the ore bed, the roof is located in the mudstone layer, the mudstone has been exposed to the humid air in the underground for a long time, and there are small cracks and a small amount of water outflow on the top, and there is a lack of effective support, which causes the roof mudstone to collapse, and the water inflow increases over time. (4) Geological structure, the main factors affecting water inflow in the geological structure are faults, fractures, solution pores, and solution cavities.

[0005] The current method for treating water disaster can be summarized by pumping, plugging and sealing. Pumping: mainly used when a small amount of water is accumulated in the mine pit during potassium salt mining, the water is pumped out of the mine pit by water pump, this method is suitable for a small amount of pore water accumulation, if it is surface water or a large amount of groundwater enters the mine pit, the method not only cannot pump out the water in the mine pit, but also the water volume will become larger and larger, because potassium salt is a soluble mineral, during pumping, a depression funnel is formed, water in the ore bed will flow to the pumping point, the water will dissolve the ore bed, leading to the formation of a dominant channel, surface water connects with groundwater to enter the ore bed, which is a fatal damage to the potassium salt mine. Plugging: in the process of potassium salt mining, when water gushing is found in the ore bed, most enterprises use the method of grouting to plug the pore to control groundwater, this method can plug the water in a short time under the condition of small water volume and no dominant channel formation, in the early stage, the method of injecting Portland cement is generally used for plugging, but Portland cement is not resistant to salt and brine corrosion, and the cement will fail after a long time, which will have a great safety hazard. Some enterprises also use special plugging materials according to the technical scheme provided by Qinghai Salt Lake, but when the water volume is large and the dominant channel is formed, the grouting difficulty will be very large, the slurry will be lost with the water flow and cannot reach the target layer, and the grouting plugging will consume a large amount of grouting materials and greatly increase the production cost of enterprises. Sealing: when a large water outlet appears in the mine house during potassium salt mining, pumping and plugging cannot solve the problem, and magnesium cement adhesive material is generally used to seal the mine house at present, and the potassium salt mine in the water outlet mine house is abandoned. This method has certain safety hazards and reduces the solid potassium salt mining rate, increasing the production cost of enterprises.

[0006] The above-mentioned methods are the common methods used by enterprises to solve water disaster at present, it can be seen that they are all due to lack of long-term planning, only for solving the current problem, and are blind measures after the occurrence of water disaster, lacking systematicness and scientificalness, and having certain safety hazards, high cost and other defects. The present application adopts source treatment, treats groundwater as a system engineering, only needs one-time investment, can benefit for a long time, and prevents solid potassium salt mine water disaster from the source. SUMMARY

[0007] The purpose of the present application is to solve the technical defects in the prior art of potassium salt mining, and to provide a solid potassium salt mining development method.

[0008] The technical scheme adopted to achieve the purpose of the present application is:

[0009] A solid potassium salt mining development method, comprising the following steps:

[0010] Step 1: diverting the surface runoff in the delineated mining area from the source to an area far away from the potassium salt mining area;

[0011] Step 2, after the surface runoff is diverted to form a new river channel in step 1, the geophysical exploration is carried out to determine the groundwater enrichment area, the hydrological hole is arranged according to the specification, and the groundwater parameters are determined;

[0012] Step 3, according to the groundwater parameters obtained in step 2, drilling is carried out at the edge of the mining area to determine the stratum distribution;

[0013] Step 4, the various drill holes in the mining area are sealed according to the specification, the grouting holes are arranged according to the water distribution of the hydrological hole, and grouting is carried out;

[0014] Step 5, mining, water points are found in the mine during the mining process, and the water is collected in the treated water collecting pit and then pumped out of the mine.

[0015] In the above technical solution, the method of geophysical exploration in step 2 includes EH4, transient electromagnetic or nuclear magnetic resonance method.

[0016] In the above technical solution, the groundwater parameters in step 2 include the total amount of groundwater and the flow direction, flow rate, stratum permeability coefficient or specific yield of groundwater.

[0017] In the above technical solution, the drill holes in step 4 include hydrological holes, exploration holes and drill holes formed in step 3.

[0018] In the above technical solution, in step 4, pressure grouting is used when grouting.

[0019] In the above technical solution, in step 4, when grouting, ordinary portland cement and fly ash are used for grouting above the salt layer roof, and magnesium cement cementitious material is used for grouting from the salt layer roof to the bottom plate.

[0020] In the above technical solution, in step 4, when grouting, multi-layer progressive curtain grouting is used in the groundwater-rich area along the boundary of the mining area, fewer grouting holes are arranged in the stratum with less groundwater, or the spacing of the grouting holes is increased, and finally a complete curtain is formed at the boundary of the mining area, which completely blocks the communication of groundwater between the mining area and the outside, so that the mining area is in an independent groundwater unit.

[0021] Compared with the prior art, the beneficial effects of the present application are:

[0022] 1. The present application treats the source of groundwater along the boundary of the mining area, and the treatment method mainly uses curtain grouting of different materials in different layers. Before curtain grouting, drilling is arranged according to the water flow direction or groundwater enrichment area of the hydrogeological hole at the boundary of the mining area, the stratum distribution of the grouting area is determined, pressure grouting is used during grouting, and different grouting materials are used in different layers, so that the hidden dangers of safety accidents caused by groundwater and surface water entering the mining layer are solved from the source.

[0023] 2. The late-stage mining of the present application only needs to deal with limited groundwater in the mining area, greatly reducing the risk of geological disasters such as groundwater leakage and roof collapse of the ore bed. BRIEF DESCRIPTION OF DRAWINGS

[0024] Figure 1 The figure shows the structure of the mining area of the present application. DETAILED DESCRIPTION

[0025] The present application will be further described in conjunction with specific embodiments. It should be understood that the specific embodiments described herein are only used to explain the present application and do not limit the present application.

[0026] EMBODIMENT

[0027] A solid potash salt mine development method, comprising the following steps:

[0028] Step 1: In the delineated mining area, the surface runoff is diverted from the source, and the surface runoff in the mining area is diverted from the source to an area away from the potash salt mining area. After a period of time, the surface runoff is diverted to form a new river channel, and then geophysical exploration is carried out;

[0029] Step 2: Determine the groundwater enrichment area by geophysical exploration, arrange hydrological holes, and determine the parameters of groundwater;

[0030] The geophysical exploration method includes EH4, transient electromagnetic, nuclear magnetic resonance, etc.

[0031] The hydrogeological drilling is arranged according to the specification, and the total amount of groundwater and the flow direction, flow rate, formation permeability coefficient, and specific yield of groundwater are determined through the hydrological holes;

[0032] Step 3: According to the parameters of groundwater obtained in step 2, drill holes are drilled at the edge of the mining area to determine the formation distribution;

[0033] Step 4: The hydrological holes, exploration holes, and drill holes formed in step 3 in the mining area are sealed according to the specification to ensure the sealing quality. The grouting holes are arranged according to the water distribution of the hydrological holes. The grouting holes above the salt layer roof are grouted with ordinary Portland cement and a small amount of fly ash, and the salt layer roof to the bottom plate is grouted with magnesium cementitious material;

[0034] The groundwater source is treated along the boundary of the mining area. The treatment method is mainly through curtain grouting of different materials in different layers. Before curtain grouting, drill holes are arranged at the boundary of the mining area according to the water flow direction or groundwater enrichment area determined by the hydrogeological holes to determine the formation distribution of the grouting area. During the grouting process, pressure grouting is used, different grouting materials are used in different layers, and the grouting holes are arranged according to the water distribution of the hydrological holes.

[0035] Along the mine boundary in the groundwater rich area can adopt multilayer progressive curtain grouting, groundwater quantity less stratum can less arrange grouting hole or increase grouting hole spacing, finally form complete curtain in the mine boundary, will be the mine and outside groundwater intercommunication completely block up, make the mine be in independent groundwater unit.

[0036] Step 5, mining, in the mining process, water point is found in the pit, water is gathered in the treated water collecting pit, and then the pit is pumped out on time, after pumping for a period of time, the water volume is obviously reduced, and finally the water point has no water.

[0037] The above only is the preferred embodiment of the present application, it should be pointed out that, for ordinary skilled person in the art, without departing from the principles of the present application, can also make a number of improvements and refinements, these improvements and refinements also should be considered as the protection scope of the present application.

Claims

1. A method for developing a solid potash salt mine, characterized by, It comprises the following steps: Step 1, diverting surface runoff in the delineated mining area to lead the surface runoff in the mining area from the source to an area far away from the potash mining area; Step 2, after the surface runoff diversion in step 1 forms a new river channel, geophysical exploration is carried out to determine the groundwater enrichment area, and hydrological holes are arranged according to the specification to determine the parameters of groundwater; Step 3, according to the parameters of groundwater obtained in step 2, drill holes at the edge of the mining area to determine the stratum distribution; Step 4, seal the various drill holes in the mining area according to the specification, and arrange the grouting holes according to the water distribution of the hydrological holes, and carry out grouting; Step 5, mining, during the mining process, water points are found in the mine pit, and water is collected in the treated water collecting pit and then pumped out of the mine pit in time; The method of geophysical exploration in step 2 includes EH4, transient electromagnetic or nuclear magnetic resonance method; the parameters of groundwater in step 2 include the total amount of groundwater and the flow direction, flow rate of groundwater, stratum permeability coefficient, and water yield; The drill holes in step 4 include hydrological holes, exploration holes, and drill holes formed in step 3, during grouting in step 4, pressure grouting is used, during grouting in step 4, ordinary Portland cement and fly ash are used for grouting above the salt layer roof, and magnesium cement cementitious material is used for grouting from the salt layer roof to the bottom, during grouting in step 4, multi-layer progressive curtain grouting is used in the groundwater-rich area along the mining area boundary, fewer grouting holes are arranged in the stratum with less groundwater, or the grouting hole spacing is increased, finally, a complete curtain is formed at the boundary of the mining area, which completely blocks the connection between the mining area and the external groundwater, so that the mining area is in an independent groundwater unit.

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