CN108104766A - Guarantor/the process for purifying water on iron content waste water injection Surface cracking stratum - Google Patents

Abstract

The invention discloses a water conservation/purification method for iron-containing sewage recharging coal mining damaged strata, respectively constructing iron-containing sewage recharging boreholes and oxygen-containing water/weak alkaline water recharging drills on the corresponding ground surface at the boundary and middle of the mining area The hole is used to effectively block the mining fractures by using the Fe(OH) ₃ flocculation sediment formed by the oxidation reaction of iron components in iron-containing sewage and oxygen-containing water/weak alkaline water. The generated Fe(OH) ₃ flocs can gradually precipitate in a certain range near the end hole of the recharging borehole to form an active iron filter membrane, which acts as a catalyst for the oxidation reaction of iron or ferrous ions, effectively ensuring the iron removal effect. Test the iron content of the gushing water resources in the low-lying areas of the underground mined-out area; if the iron content still exceeds the standard, the underground water gushing water will be transported to a relatively high-lying place through pipelines, and recharged by drilling inclining underground Continue the oxidation reaction and iron removal in the aquifer of the formation; if the iron content of the underground water gushing does not exceed the standard, it will be directly transported to other mining areas or reused on the ground.

Description

Water conservation/purification method for iron-containing sewage backfilling coal mining damage strata

technical field

The invention relates to a method for protecting and purifying water resources, in particular to a water conservation/purification method suitable for recharging iron-containing sewage into strata damaged by coal mining in the fields of formation aquifer restoration and water resource protection in coal mining areas.

Background technique

Underground coal mining will cause the movement and destruction of the overlying strata, thereby forming mining fissures in the overlying rock. The mining fissures in the overlying rock not only provide a channel for regional water loss, but also become the geological source of ecological environment damage in the mining area. Therefore, how to control the development of water-conducting fissures in mining overlying rocks and seal the leakage channels of underground aquifer water resources, so as to improve and protect the ecological environment of coal mining areas, is a major technical problem faced by most coal mining areas.

On the other hand, the daily life and industrial production of residents in coal mining areas and surrounding cities will produce a large amount of sewage, which usually contains excessive iron components, and iron removal has become a necessary process for artificial purification of these sewage. The mature iron removal method is to uniformly transport the iron-containing sewage to the sewage treatment plant, and artificially add chemicals through aeration, oxidation reaction, sedimentation and filtration, etc., to promote the iron components in the sewage to form Fe( OH) ₃ and flocculation and precipitation, and finally complete the removal of iron from sewage.

Inspired by this, if the iron removal process of the above-mentioned iron-containing sewage can be transferred to the fractures of the rock mass damaged by mining, the Fe(OH) ₃ flocculation sediment formed by iron removal will be able to effectively seal the mining fractures. In this way, it can not only effectively isolate the water leakage channel of the stratum aquifer, but also effectively remove iron and purify the iron-containing sewage, so as to achieve the purpose of water conservation in coal mining and natural purification of sewage in coal mining areas. Therefore, based on the development range and distribution characteristics of water-conducting fissures in the mining overlying rock, it is necessary to carry out the special design of water conservation/purification methods for iron-containing sewage recharge and coal mining-damaged formations.

Contents of the invention

Purpose of the invention: In order to overcome the deficiencies in the prior art, the present invention provides a water conservation/purification method for recharging iron-containing sewage to destroy formations during coal mining, and the iron-containing sewage and oxygen-containing water/weak alkaline water Backfill into the formation aquifer damaged by coal mining, and use the Fe(OH) ₃ flocculation sediment generated by the oxidation reaction of iron components in the iron-containing sewage to seal the mining fractures, thereby isolating the water loss channel of the formation aquifer, and effectively Reduce the iron content of iron-containing sewage, and finally achieve the protection of groundwater resources in coal mining areas and the purification of iron-containing sewage.

Technical scheme: in order to achieve the above object, the technical scheme adopted in the present invention is:

A water conservation/purification method for iron-containing sewage recharge coal mining damaged strata. According to the development characteristics and distribution range of water-conducting fissures in the mining overlying rock, iron-containing sewage recharge boreholes are respectively constructed on the corresponding surface in the boundary and middle of the mining area and oxygenated water/weak alkaline water to recharge the borehole, and use the Fe(OH) ₃ flocculation sediment formed by the oxidation reaction of iron components in iron-containing sewage with oxygenated water/weak alkaline water to effectively block the mining fractures. The generated Fe(OH) ₃ flocs can gradually precipitate in a certain range near the end hole of the recharge borehole to form an active iron filter membrane, which acts as a catalyst for the oxidation reaction of iron (or ferrous) ions, effectively ensuring iron removal Effect. At the same time, the iron content of the gushing water resources is tested in the low-lying areas of the underground mined-out area; if the iron content still exceeds the standard, the underground water gushing water will be transported to a relatively high-lying place through pipelines, and the drilling will be re-drilled by using the down-hole construction. Recharge into the formation aquifer to continue the oxidation reaction and iron removal; and if the iron content of the downhole water does not exceed the standard, it will be directly transported to other mining areas or the ground for reuse.

Specifically include the following steps:

a. According to the height of the water-conducting fissure zone in the overlying rock and the columnar shape of the geological drilling hole, the coal mining area where the formation aquifer is damaged by mining is judged. If there is an aquifer within the height range of the water-conducting fracture zone, the water-conducting fracture zone in the corresponding area has communicated with the aquifer, and corresponding recharge boreholes need to be arranged; Fill the borehole.

Preferably: the height of the water-conducting fissure zone can be detected according to on-site measurement methods such as the drilling flushing fluid loss method, or can be carried out by using theoretical calculation methods such as "prediction method for the height of the water-conducting fracture zone based on the position of the key layer" judge.

b. Construct iron-containing sewage recharge boreholes and oxygen-containing water/weak alkaline water recharge boreholes on the corresponding surface in the mining area where the water-conducting fissure zone communicates with the formation aquifer.

Preferably: the iron-containing sewage recharge boreholes are arranged near the outside of the mining area boundary and in the center of the mining area, and the boreholes arranged near the outside of the mining area boundary should be located outside the lateral development boundary of the water-conducting fracture zone, and the distance from the mining area to Zone boundaries should reach 30-40m.

Preferably: the oxygen-containing water/weak alkaline water recharge borehole is arranged near the inner side of the mining area boundary, 10-20m away from the mining boundary.

Preferably: when the strike and dip of the mining area exceed 1000m, iron-containing sewage recharge boreholes and oxygenated water/weak alkaline water recharge boreholes can be arranged in groups at intervals of 1000m along the strike or dip

Preferably: the construction method of the surface iron-containing sewage recharge borehole and the oxygen-containing water/weak alkaline water recharge borehole is as follows: when the borehole is constructed, the diameter of the hole is 120-140mm, and it needs to be drilled to the point where the water is guided. At a certain depth below the top interface of the aquifer communicated by the fractured zone, the distance between the end hole of the borehole and the top interface of the aquifer communicated by the said water-conducting fracture zone should not be less than 0.3-0.5 of the thickness of the aquifer communicated by the water-conducting fracture zone times. Casing protection holes are used within 10m below the top interface of the aquifer that communicates with the water-conducting fissure zone, and flower tube protection holes are used for drilling holes in the aquifer that communicates with the water-conducting fissure zone. After the drilling construction, the hole is covered with a closed cover plate, and the closed cover plate is connected with a water delivery pipeline.

c. Arrange drainage pipelines in the corresponding low-lying areas of the mined-out area, and test the iron content of the goaf drainage, and consider whether to recharge or directly reuse according to the iron content in the goaf drainage. The steps are as follows:

If the iron content in gob drainage still exceeds the relevant national standards, pipelines will be used to transport it to relatively high terrain in the mining area, and refilling will be carried out to the guideway by constructing refilling boreholes in nearby roadways. In the formation aquifer connected by the water fissure zone, iron removal and purification are carried out again.

If the iron content in gob drainage is lower than the relevant national standards, it will be directly transported to other underground mining areas or the ground for reuse through pipelines.

Preferably: the final hole position of the recharge borehole for underground construction should reach about 5m above the bottom interface of the aquifer communicated by the water-conducting fracture zone, and the horizontal distance between the final hole position and the mining boundary is 10-20m, and it is in the mining area. inside the border. Casing protection holes are used in the section that has not been damaged by mining fissures, and flower tube protection holes are used in the range of entering the water-conducting fissure zone.

The present invention is based on the development law and distribution characteristics of the water-conducting fissures in the mining-covered rock, and fully utilizes the Fe(OH) ₃ flocculation sediment generated by the oxidation reaction of iron components in the iron-containing sewage to seal the water-conducting fissures, which not only isolates the formation water It also effectively reduces the iron content of iron-containing sewage, realizes the in-situ protection of formation aquifers in coal mining areas and the iron removal and purification of iron-containing sewage, which can be used for the protection and efficient utilization of water resources in coal mining areas etc. to provide guarantees, its method of use is reliable, and its practicability is strong. Compared with the prior art, the present invention has the following advantages:

(1) Using the sediment in the iron-containing sewage purification process to seal the water-conducting fissures of the overlying rock is not only scientific and reliable, but also has a low engineering effort, and can effectively reduce the degree of water loss in the aquifer and purify the iron-containing water at low cost. sewage;

(2) The determination of water conservation and water purification methods that can adapt to the iron-containing sewage recharge coal mining damaged strata under different mining conditions can provide a basis for the coordinated development of coal mining and water resource protection in my country's high iron-containing sewage and water-scarce mining areas Guarantee, its implementation method is simple and practical.

Description of drawings

Fig. 1 is the plan view of recharging borehole arrangement of the present invention;

Fig. 2 is the A-A sectional view of recharging borehole arrangement of the present invention;

Fig. 3 is the B-B sectional view of recharging drilling layout of the present invention;

Fig. 4 is the sectional view of recharging borehole of the present invention;

Fig. 5 is a schematic diagram of the development height of the columnar and water-conducting fissure zone in the 22301 working face Z1 of a certain coal mine in the actual application process of the present invention;

Fig. 6 is a plan view of the arrangement of recharge drilling holes in the 22301 working face of a certain coal mine during the actual application of the present invention.

Among them, 1 represents the iron-containing sewage recharge borehole, 2 represents the oxygen-containing water/weak alkaline water recharge borehole, 3 represents the underground construction recharge borehole, 4 represents the casing, 5 represents the floral tube, and 6 represents the Fe(OH ) ₃ active filter membrane.

Detailed ways

Below in conjunction with accompanying drawing and specific embodiment, further illustrate the present invention, should be understood that these examples are only for illustrating the present invention and are not intended to limit the scope of the present invention, after having read the present invention, those skilled in the art will understand various aspects of the present invention All modifications of the valence form fall within the scope defined by the appended claims of the present application.

As shown in Figures 1 to 4, a water conservation/purification method for iron-containing sewage backfilling coal mining damaged strata according to the present invention, according to the development characteristics and distribution range of water-conducting fissures in the mining overlying rock, respectively at the boundary of the mining area Construct iron-containing sewage recharge borehole 1 and oxygenated water/weak alkaline water recharge borehole 2 corresponding to the surface in the middle, using Fe(OH) generated by the oxidation reaction of iron components in ferrous sewage with oxygenated water/weak alkaline water _3. Flocculate sediments to effectively block mining fissures. The generated Fe(OH) ₃ flocs can gradually precipitate in a certain range near the end hole of the recharging borehole to form an active iron filter membrane 6, which acts as a catalyst for the oxidation reaction of iron (or ferrous) ions, effectively ensuring the removal of iron effect. At the same time, the iron content of the gushing water resources is tested in the low-lying areas of the underground mined-out area; if the iron content still exceeds the standard, the underground water gushing water will be transported to a relatively high-lying place through pipelines, and the underground drilling will be used to construct the recharge drill Hole 3 is refilled into the aquifer damaged by mining to continue the oxidation reaction and iron removal purification; if the iron content of the underground water gushing does not exceed the standard, it will be directly transported to other mining areas or the ground for reuse. Specifically include the following steps:

a. According to the height of the water-conducting fissure zone in the overlying rock and the columnar shape of the geological drilling hole, the coal mining area where the formation aquifer is damaged by mining is judged. If there is an aquifer within the height range of the water-conducting fracture zone, the water-conducting fracture zone in the corresponding area has communicated with the aquifer, and corresponding recharge boreholes need to be arranged; Fill the borehole.

The height of the water-conducting fissure zone can be detected according to on-site measurement methods such as the drilling flushing fluid loss method, or can be judged by theoretical calculation methods such as "the method of predicting the height of the water-conducting fracture zone based on the position of the key layer".

b. Construct iron-containing sewage recharge boreholes and oxygen-containing water/weak alkaline water recharge boreholes on the corresponding surface in the mining area where the water-conducting fissure zone communicates with the formation aquifer.

The iron-containing sewage recharge boreholes are arranged near the outside of the mining area boundary and in the center of the mining area. The boreholes arranged near the outside of the mining area boundary should be located outside the lateral development boundary of the water-conducting fracture zone, and the distance from the mining area boundary should be Reach 30-40m.

The oxygen-containing water/weak alkaline water recharge borehole is arranged near the inner side of the mining area boundary, 10-20m away from the mining boundary.

When the strike and dip dimensions of the mining area exceed 1000m, iron-containing sewage recharge boreholes and oxygenated water/weak alkaline water recharge boreholes can be arranged in groups at intervals of 1000m along the strike or dip

The construction method of the surface iron-containing sewage recharge borehole and the oxygen-containing water/weak alkaline water recharge borehole is as follows: when the borehole is constructed, the diameter of the hole is 120-140mm, and it is necessary to drill into the water-guided fissure zone to communicate At a certain depth below the top interface of the aquifer, the distance between the top interface of the aquifer where the end hole of the borehole communicates with the water-conducting fracture zone should not be less than 0.3-0.5 times the thickness of the aquifer. The casing 4 protection holes are used within 10m below the top interface of the aquifer that communicates with the water-conducting fissure zone, and the boreholes in the aquifer that communicate with the water-conducting fissure zone use flower tube 5 protection holes. After the drilling construction, the hole is covered with a closed cover plate, and the closed cover plate is connected with a water delivery pipeline.

c. Arrange drainage pipelines in the corresponding low-lying areas of the mined-out area, and test the iron content of the goaf drainage, and consider whether to recharge or directly reuse according to the iron content in the goaf drainage. The steps are as follows:

If the iron content in gob drainage still exceeds the relevant national standards, pipelines will be used to transport it to relatively high terrain in the mining area, and refilling will be carried out to the guideway by constructing refilling boreholes in nearby roadways. In the aquifer connected by the water fissure zone, iron removal and purification are carried out again.

If the iron content in gob drainage is lower than the relevant national standards, it will be directly transported to other underground mining areas or the ground for reuse through pipelines.

The position of the final hole of the recharge drilling in the underground construction should reach about 5m above the bottom interface of the aquifer communicated by the water-conducting fracture zone, and the horizontal distance from the position of the final hole to the mining boundary is 10-20m, and it is inside the mining boundary . Casing protection holes are used in the section that has not been damaged by mining fissures, and flower tube protection holes are used in the range of entering the water-conducting fissure zone.

As shown in Figure 5, the figure is a schematic diagram of the development height of the Z1 drilling columnar and water-conducting fracture zones in the mining area during the actual application of the 22301 working face in a coal mine. The water fissure zone has communicated with the formation aquifer. Therefore, it is necessary to implement ground drilling to recharge iron-containing sewage and oxygenated water/weak alkaline water in the mining area of the working face.

As shown in Fig. 6, considering that the strike advance length of the 22301 working face is long (up to about 4000m), the recharging boreholes were arranged at an interval of 1000m along the strike advance direction near the mining boundary on both sides of the work face, and at the same time Iron-containing sewage recharge boreholes are also arranged in the middle of the corresponding working face between the two groups of recharge boreholes. According to the occurrence of rock formations revealed by drilling Z1, the final hole depth of the recharge drilling hole is 60m, and has entered the aquifer 41.54m (reaching 0.3-0.5 times the thickness of the aquifer).

The present invention is based on the development law and distribution characteristics of the water-conducting fissures in the mining-covered rock, and fully utilizes the Fe(OH) ₃ flocculation sediment generated by the oxidation reaction of iron components in the iron-containing sewage to seal the water-conducting fissures, which not only isolates the formation water It also effectively reduces the iron content of iron-containing sewage, realizes the in-situ protection of formation aquifers in coal mining areas and the iron removal and purification of iron-containing sewage, which can be used for the protection and efficient utilization of water resources in coal mining areas etc. to provide protection.

The above is only a preferred embodiment of the present invention, it should be pointed out that for those of ordinary skill in the art, without departing from the principle of the present invention, some improvements and modifications can also be made, and these improvements and modifications are also possible. It should be regarded as the protection scope of the present invention.

Claims (10)

1. A method for protection/purification of iron-containing sewage backfilling coal mining damage formation, characterized in that: it specifically comprises the following steps: a. According to the height of the water-conducting fissure zone in the overlying rock and the columnar shape of the geological drilling hole, determine the coal mining area where the formation aquifer is damaged by mining; b. Carry out iron-containing sewage recharge drilling and oxygenated water/weak alkaline water recharge drilling in the mining area where the water-conducting fissure zone communicates with the stratum aquifer corresponding to the surface, and iron-containing sewage and oxygenated water/weak alkali The water is reinjected into the aquifer of the communication formation in the water-conducting fracture zone, and the iron component in the iron-containing sewage reacts with the oxygen-containing water/weak alkaline water to form Fe(OH) ₃ flocculation sediment, which seals the mining fracture and blocks the water-bearing The water leakage channel in the upper layer can reduce the iron content of the iron-containing sewage; c. Arrange drainage pipelines in the corresponding low-lying areas of the mined-out area, and test the iron content of the goaf drainage, and consider whether to recharge or directly reuse according to the iron content in the goaf drainage. 2. The water conservation/purification method for iron-containing sewage backfilling coal mining to destroy strata according to claim 1, characterized in that: in step a, if there is an aquifer in the height range of the water-conducting fracture zone, then the corresponding area is water-conducting The fissure zone has communicated with the aquifer, and corresponding iron-containing sewage recharge boreholes and oxygenated water/weak alkaline water recharge boreholes need to be arranged; if there is no aquifer within the height range of the water-conducting fissure zone, no recharge borehole needs to be constructed hole; The height of the water-conducting fissure zone is detected by on-site measurement methods including the method of drilling flushing fluid leakage, or judged by theoretical calculation methods including the method of predicting the height of the water-conducting fracture zone based on the position of the key layer . 3. The water protection/purification method for iron-containing sewage recharge coal mining damage strata according to claim 1, characterized in that: in step b, the iron-containing sewage recharge boreholes are arranged at the outer side of the mining area boundary and In the center of the mining area, the boreholes arranged outside the boundary of the mining area are located outside the lateral development boundary of the water-conducting fracture zone, 30-40m away from the boundary of the mining area. 4. The water conservation/purification method for iron-containing sewage recharge coal mining damage formation according to claim 1, characterized in that: in step b, the oxygen-containing water/weak alkaline water recharge borehole is arranged in the mining area The position inside the boundary, 10-20m away from the mining boundary, is set along the strike or dip respectively. 5. The water conservation/purification method for iron-containing sewage recharge coal mining damage formation according to claim 1, characterized in that: the iron-containing sewage recharge borehole and oxygen-containing water/weak alkaline water recharge borehole It is arranged symmetrically along the central axis of the strike and dip direction of the mining area. 6. The water conservation/purification method for iron-containing sewage backfilling coal mining to destroy strata according to claim 1 or 5, characterized in that: the direction or inclination size of the mining area where the water-conducting fissure zone communicates with the stratum aquifer is greater than At 1000m, the iron-containing sewage recharge boreholes and oxygenated water/weak alkaline water recharge boreholes are arranged at intervals of 1000m along the strike or inclination. 7. The method for protection/purification of iron-containing sewage backfilling coal mining damage strata according to claim 1, characterized in that: in step b, the surface iron-containing sewage backfilling borehole and oxygen-containing water/weak alkali The construction method of water recharge drilling is as follows: during drilling construction, drill holes with a diameter of 120-140mm, drill into below the top interface of the formation aquifer communicated with the water-conducting fracture zone damaged by mining, and finally drill the hole. The distance between the hole and the top interface of the formation aquifer communicating with the water-conducting fracture zone is not less than 0.3-0.5 times the thickness of the formation aquifer communicating with the water-conducting fracture zone. 8. The water conservation/purification method for iron-containing sewage backfilling coal mining to damage the formation according to claim 1, characterized in that: the ground surface communicates with the water-conducting fissure zone within the range of 10m below the top interface of the stratum aquifer. Casing protection holes, the boreholes in the stratum aquifer communicated with the water-guiding fissure zone adopt flower tube protection holes; after the drilling construction, the holes are covered with a closed cover plate, and the closed cover plate is connected with a water delivery pipeline . 9. The water conservation/purification method for iron-containing sewage backfilling coal mining to destroy formations according to claim 1, characterized in that: in step c, the iron composition test is carried out on the gushing water resources in the low-lying place of the underground goaf , If the iron content exceeds the standard, the underground inrush water will be transported to relatively high ground through pipelines, and the recharge borehole will be recharged into the aquifer connected by the water-conducting fracture zone to continue the oxidation reaction and iron removal by using the downhole tilting construction recharge borehole purify; If the iron content of the underground water gushing does not exceed the standard, it will be directly transported to other mining areas or reused on the ground. 10. The water conservation/purification method for iron-containing sewage backfilling coal mining to destroy strata according to claim 9, characterized in that: the position of the end hole of the downhole tilting construction backfilling borehole reaches the water-conducting fissure zone 5-10m above the bottom interface of the aquifer in the stratum, the horizontal distance between the position of the final hole and the mining boundary is 10-20m, and it is inside the mining boundary; Holes, flower tubes are used to protect the holes in the range of entering the water-guiding fissure zone.