CN1221479C - Water purification method for coal mine worked-out section - Google Patents

Abstract

The present invention provides a purifying method of water in an underground worked-out area of a coal mine, which comprises the following steps: firstly, a water collecting area is built in a specific area of a mine coal bed; then, a water blocking facility and a reservoir are built on the edge of a worked-out area so as to block the water leakage in the worked-out area, the full deposition is carried out, and simultaneously, the water leakage accidents in the worked-out area can be prevented; a diving and self-guiding water crack gap of a guiding rock bed is guided to the worked-out area through a caving zone; then, the mine water in the worked-out area is guided to be collected to the water collecting area through the filtration and the seepage flow of gangue in the worked-out area; the filtered mine water is guided to a special sump for water storage through a pipeline, and the secondary deposition is carried out; the deposited purified water is discharged to an industrial water pipe network in a mine area through the special sump and a water discharge facility. In the purifying process, the present invention comprises the physicochemical processes, such as filtration, deposition, absorption, exchange with ions and authigenic mineral generating action.

Description

The coal mine gob water purification method

Technical field

The present invention relates to a kind of method for purifying water, be specifically related to a kind of coal mine gob water purification method, can purify coal mine gob ponding multiplexing.

Background technology

Coal mine gob ponding belongs to industrial sewage, for fear of it coal mining is worked the mischief, and production unit is all discharged this part water well no longer utilization outward generally speaking.In recent years, because the scarcity of water resources and the enhancing of environmental consciousness, China Datong District mineral bureau, company of Yanzhou Mining Group, mining area, Xuzhou, Shizuishan mining area etc. have some mines to begin multiplexing this part water resources.The way of taking is water to be drained into surface water treatment plant carry out relevant treatment, recycling then, and obtained favorable social and economic benefits.Refreshing Fu Dong wins each grass of mining area and has all built sewage work, and has carried out the multiplexing or qualified discharge of water treatment, and the water price after still handling is up to 3.2 yuan/cubic metre, and cost is higher, and multiplexing benefit is relatively poor.

Summary of the invention

The invention provides a kind of coal mine gob water purification method, may further comprise the steps:

1) at first constructs the catchment area at the lowest part of mine coal seam;

2) build dash facility and water reservoir then at the edge, worked-out section, the water that intercepts the worked-out section leaks, and makes it abundant precipitation, prevents the generation of worked-out section water leak accident simultaneously;

3) guiding rock stratum diving imports worked-out section through caving zone through behind the filteration from water flowing fractured zone;

4) collect in the catchment area after guiding the worked-out section pit water to filter seepage flow then by the worked-out section spoil;

5) pit water after will filtering is introduced the sump retaining by pipeline, carries out secondary sedimentation;

6) purifying waste water of post precipitation drained into mining area process water pipe network via sump and pumping equipment pipe.

In scavenging process, comprise filtration, precipitation, absorption and ion-exchange and these physical and chemical processes of authigenic mineral nucleus formation.Wherein, filtration procedure occurs in step 3) and step 4); Precipitation process occurs in step 4) and step 5); Absorption occurs in step 3) and step 4) with ion exchange process; Authigenic mineral nucleus formation process occurs in step 3) and step 4).

Description of drawings

Fig. 1 is the synoptic diagram of worked-out section water purification process of the present invention;

Fig. 2 is the schema of purifying method of the present invention.

Embodiment

Below in conjunction with accompanying drawing, describe the principle and the method for pit water of the present invention worked-out section filtering and cleaning technique in detail.

The water filling of mine condition analysis shows water filling of mine water source, mining area mainly from Quaternary system gravel rock stratum diving and Atmospheric precipitation, and water quality is with HCO ₃-Ca type is main, and salinity is lower.Sulfide content is low in the goaf filling thing in addition, carbonate content is higher, therefore the acid of pit water forming process forms not obvious, can not cause the chemical property and the underground water of pit water that big difference is arranged, its main difference is that suspension content is higher, and pouring in of bedrock fracture diving will cause a part of ion such as chlorine, sodium etc. to increase.According to feature of pit water chemical property and geology, hydrogeological conditions, goaf filling thing etc., pit water of the present invention worked-out section filtering and cleaning technique relates to physical and chemical processes such as filtration, precipitation, absorption and ion-exchange, authigenic mineral nucleus formation.Existing division is as follows:

(1) filtering process in pit water worked-out section and stage

According to the present invention, Quaternary system gravel rock stratum diving pours in the worked-out section from water flowing fractured zone through caving zone and converges to the catchment area again and experienced two filtration stages.

Fs: be the gravel filtration stage of filling in water flowing fractured zone and caving zone.Because the Quaternary system sandy gravel stratum is the direct water filling source of mining area mine, the sandy gravel stratum clay content is very little, sandstone has comparative advantage, grain composition good (table 1), particle alignment is comparatively tight, when back production roof collapse in coal seam during to bedrock surface, gravel will be filled in wherein, form filtering layer, the total suspended solids that underground water is carried greatly reduces, thereby pit water water quality is better.

Table 1 sandy gravel stratum grain size characteristic

Sample number	Particle size distribution (%)					The restriction particle diameter
								＞10mm	10-2mm	2-0.5mm	0.5-0.25mm	＜0.25mm	d 60(mm)	d 30(mm)

1	20	47	22	7	4	5.4	1.142
								2	47	19	18	10	6	14.3	1.52
3	46	31	12	5	6	13.5	3.40
								4	19.7	44	23.7	7.3	5.3	4.42	1.45
5	37.1	27.8	20.9	6.6	5.4	9.60	1.68
								On average	33.96	33.76	19.32	7.18	5.34	9.444	1.838

Subordinate phase: occur in pit water converges the catchment area from the worked-out section process, the goaf filling thing is to the filteration of pit water.Because goaf filling thing grating is better, roof and floor easy argillization in coal seam is filled between the particulate space, makes between charges the space less, to suspended substance filtration in the pit water.Owing to containing certain amount of clay mineral pair bacterium, the coal seam roof and floor also produces filteration simultaneously.

According to the present invention, filteration mainly occurs in the particle intergranular pore, so the big or small and distribution of particle intergranular pore is the principal element of decision filter effect quality.Water is seepage flow in the motion of intergranular.

(2) precipitating action

Precipitating action of the present invention is to remove the important step of pit water suspended substance, and according to water filling of mine condition and worked-out section geologic condition, precipitating action also can be divided into two stages.

Fs: occur in pit water from worked-out section seepage flow in the process to the catchment area, precipitating action occurs in the worked-out section.Because mine inflow is less, seat earth inclination angle very little (being generally less than 4 degree), the space is less between charges in addition, so the motion of pit water in charges is seepage effect.Because hydraulic gradient is little, the existence of goaf filling thing is arranged again simultaneously, so pit water is slow especially in the motion in worked-out section, precipitation takes place simultaneously with filteration, makes the suspended substance that enters the catchment area greatly less;

Subordinate phase: occur in the catchment area.Be in stationary state in the catchment area owing to water base, therefore precipitating action of the present invention is the one of the main reasons that occurs in the catchment area, also is the final stage of removing suspended substance.

(3) absorption and ion exchange

Absorption of the present invention and ion exchange mainly occur in the worked-out section and flow in the process of catchment area, are the main paties of removing harmful ion and fine particle in the pit water.Because sandstone, siltstone mesoporosity rate are between the 5-13% in the goaf filling thing, these materials will produce certain adsorption to some harmful ions in the pit water and fine particle.What is more important contains the certain amount of clay mineral owing to the coal seam roof and floor, and mainly is based on montmorillonite, has stronger absorption and cationic exchange effect (table 2, table 3).Because the Ph value of pit water is neutrality-weakly alkaline, so the surface of clay mineral is a negative electricity, so clay mineral will adsorb positive ion.Simultaneously, because montmorillonite is ca-montmorillonite, some positive ions in the pit water will exchange calcium ion wherein as sodium, potassium ion, make that calcium ion increases in the pit water.

The mineral composition of table 2 clay mineral

Sample number	Montmorillonite (%)	Kaolinite (%)	Illite (%)	Quartzy (%)	Feldspar (%)	Calcite (%)	Sucking amount mmd/100g
								J154 J156 J181 J182 J184 J185 mean value	90 74 79 70 80 69 77	3 10 10 10 5 10 8	5 8 5 8 6 12 7.3	2 3 3 7 3 4 3.7	/ / / 5 3 3 1.8	/ 5 3 / 3 3 2.3	80.00 67.06 73.50 58.14 74.52 55.11 68.05

The cationic exchange of table 3 clay mineral

Sample number	Cationic exchange total amount m.e/100g	Exchangeable sodium m.e/100g	Exchangeable potassium m.e/100g	Exchangeable calcium m.e/100g	Exchangeability magnesium m.e/100g	The alkalescence coefficient	Sodium calcium ratio
								J154 J156 J181 J182	54.85 47.82 55.13 42.98	8.15 5.49 5.93 4.40	1.59 2.10 1.36 1.07	37.50 35.88 32.62 33.62	7.61 4.35 15.22 4.35	0.22 0.19 0.15 0.15	0.21 0.15 0.18 0.13

J184 J185 is average

48.02 40.41 48.20

5.27 3.75 5.50

1.43 1.33 1.48

35.34 29.35 34.05

5.98 5.98 7.25

0.16 0.06 0.17

0.15 0.13 0.16

(4) authigenic mineral nucleus formation

Because pit water mainly from the Quaternary system waterbearing stratum, contains more solvability carbonic acid gas in the water, form bicarbonate radical, bicarbonate radical will form Calcium hydrogen carbonate, magnesiumcarbonate, lime carbonate etc. with calcium, the magnesium ion effect in the pit water.Therefore, though,, make that calcium ion reduces significantly in the pit water because the authigenic mineral nucleus formation will take place for the existence of solvability carbonic acid gas because ion exchange is increased the calcium ion in the pit water.

Therefore,, the invention provides a kind of coal mine gob water purification method, may further comprise the steps: at first construct the catchment area in the specific region of mine coal seam according to above analysis; Build dash facility and water reservoir then at the edge, worked-out section, the water that intercepts the worked-out section leaks, and makes it abundant precipitation, can prevent the generation of worked-out section water leak accident simultaneously; Guiding rock stratum diving imports the worked-out section from water flowing fractured zone through caving zone; Collect in the catchment area after guiding the worked-out section pit water to filter seepage flow then by the worked-out section spoil; Pit water after filtering is introduced special-purpose sump retaining by pipeline, carry out secondary sedimentation; Purifying waste water of post precipitation drained into mining area process water pipe network via special-purpose sump and pumping equipment pipe.

The applicant has chosen six lower panels of mine coal seam base plate absolute altitude as the mine catchment at the beginning of the design of the fully-mechanized mining working in Da Liu tower colliery, Shen Dong mining area, therefore after finishing, 12601 working face minings implemented a series of engineerings: 1) the water-proof sealing wall has been built in catchment area, 12601 worked-out section, its objective is, the obstruct goaf water leaks, make it abundant precipitation, can prevent the generation of worked-out section water leak accident simultaneously.2) build several sump at working face crossheading collar extension, sump is connected with 10 cun water pipes with the catchment area, and water can be flowed automatically in the sump.3) establish big pump and network of drains in the sump, outwards supply water, a part is as the down-hole water, all the other connect from flowing to ground and surface pipeline network by 10 cun water pipes, part water is directly imported coal washery, heat power plant as process water, another one enters sewage work, enters the biotope waterworks after further purifying treatment reaches drinking water standard, and its schedule drawing is seen Fig. 1.

In scavenging process, comprise filtration, precipitation, absorption and ion-exchange and these physical and chemical processes of authigenic mineral nucleus formation.

Wherein, described filtration procedure occurs in step 3) and step 4), described precipitation process occurs in step 4) and step 5), and described absorption and ion exchange process occur in step 3) and step 4), and described authigenic mineral nucleus formation process occurs in step 3) and step 4).

According to chart the utilization of filtration, purification effect and pit water is discussed below.

Because in the worked-out section, physical and chemical processes such as the catchment area filters, precipitates, absorption and ion exchange, authigenic mineral nucleus formation, suspended substance, calcium ion and other harmful ion reduce significantly in the pit water, can after further purifying, can be used as tap water and incorporate the network of rivers into directly as process water.Water quality characteristic behind the filtration, purification of worked-out section is as shown in table 4.

Table 4 purify the back pit water the water chemistry feature and with the comparison of unconsolidated formation water, basement rock water

Analysis project	Quaternary system unconsolidated formation diving	Basement rock water	Purify back pit water *
				K+Na +Mg/ rises Ca 2+Mg/ rises Mg 2+Mg/ rises NH 4 + Cr 6+ Cl -Mg/ rises SO 4 2-Mg/ rises HCO 3 -Mg/ rises NO 2 -Total hardness (German degree) permanent hardness (German degree) total alkalinity (equivalent parts per million) aggressiveness CO 2The mg/ liter	1.84-39.33 35.27-56.91 8.26-14.58 4.0-20.0 0-24.0 159.8-249.56 7.40-9.08 0-0.22 0-6.89	20.01-425.96 34.47-55.31 2.43-23.81 4.0-555.0 14.0-100.0 165.97-268.47 5.38-11.10 0 4.61-6.92	44.49 8.99＜0.03 do not detect 6.38 100.00 5.586 (equivalent parts per million)＜0.003 148.13 (calcium carbonate meter) 5.586

Smelly and the flavor naked eyes visible total number of bacteria coliform group count sample size of PH colourity turbidity

7.28-7.89 11

7.40-11.66 11

7.51 0.25 0.00 do not have not to have 63/ml＜3/l 1

Below pit water worked-out section filtering and cleaning technique effect is analyzed.

Table 4 shows in the pit water that outside the sulfate radical ion ratio unconsolidated formation underground water content height, other ion is all comparable with unconsolidated formation underground water, is neutrality-weakly alkaline, colourity is low, odorless and flavor, the visible suspended substance of no naked eyes, total plate count is few, can be used as tap water after the processing directly as process water.

Table 4 shows that also oxygenizement has taken place pyrite in the coal, therefore causes sulfate ion content to increase.But because pyrite content is low in the coal, pyritous oxygenizement can not cause the variation of pit water generation matter.Though the exchange interaction of calcium ion in other positively charged ion and the ca-montmorillonite takes place, owing to contain the solvability carbonic acid gas in the pit water, calcium ion and its generation chemical reaction generate lime carbonate etc., so how many calcium ion contents do not improve in the pit water.From the result of table 4 as can be seen, aforesaid filtration, precipitation, absorption and ion-exchange, authigenic mineral nucleus formation etc. all is present in the filtration, purification process of pit water worked-out section.Therefore, the exploitation of worked-out section filtering and cleaning technique is that the material composition of mine hydrogeology condition, worked-out section geologic condition, goaf filling thing, constitutional features etc. are had on the basis of heightened awareness, analyzes to carry out under the prerequisite of physics chemical action possible in the filtration, purification process of worked-out section and effect thereof.Must understand possible pollution course and scavenging process and effect thereof in depth on stream, could shoot the arrow at the target.

Purify the back pit water and be mainly used in three aspects, the one, dust removing down-hole, fire-fighting etc.; The 2nd, as the process water of coal washery, heat power plant; The 3rd, after further purifying treatment, incorporate pipe network into, for domestic water.Pit water worked-out section purification filtering The Application of Technology not only produces huge economic benefit, and its environmental ecology effect is more remarkable.

Owing to adopt the worked-out section filtering and cleaning technique, except that cost of erection such as the catchment area at initial stage, sump and drainage pipeline laying expense, do not have sewage disposal expense substantially, so its processing costs is extremely cheap.

The economic benefits that pit water utilizes are extremely remarkable, are example with Da Liu tower ore deposit, and per hour the pit water flow is about 280 cubic metres, and can reach 245 ten thousand steres the whole year.Therefore the price of mining area process water is 3.2 yuan/cubic metre, and effluent charge are 0.96 yuan/cubic metre, utilizes pit water can produce 7,840,000 yuan/year of economic benefits, saves surplus the effluent charge 235 ten thousand yuan/year, and annual direct economic benefit is surplus in the of 1,019 ten thousand yuan.

At present full mining area pit water utilization reaches 13580m every day ³, annual 495.67 ten thousand steres account for 72% of original mine day total amount of pollutants discharged, and the economic benefit of generation is surplus in the of 1,586 ten thousand yuan/year, saves surplus the effluent charge 342 ten thousand yuan/year, and total direct economic benefit is surplus in the of 1,928 ten thousand yuan/year.

The environmental and ecological benefit of pit water utilization shows the following aspects, the one, basically eliminate the pollution of the surface water body that causes of pit water; The 2nd, reduced the utilization of the surface water body water yield, help keeping and improve of face of land ecotope; The 3rd, reduced amount of groundwater mining, slow down the decline of ground water table, keep the water retention capacity of topsoil, prevent erosion; The 4th, the greening that pit water can directly apply to mining area and surrounding area improves with ecological.

Claims (1)

1. coal mine gob water purification method may further comprise the steps:

1) at first constructs the catchment area at the lowest part of mine coal seam;

2) build dash facility and water reservoir then at the edge, worked-out section, the water that intercepts the worked-out section leaks, and makes it abundant precipitation, prevents the generation of worked-out section water leak accident simultaneously;

3) guiding rock stratum diving imports worked-out section through caving zone through behind the filteration from water flowing fractured zone;

4) collect in the catchment area after guiding the worked-out section pit water to filter seepage flow then by the worked-out section spoil;

5) pit water after will filtering is introduced the sump retaining by pipeline, carries out secondary sedimentation;

6) purifying waste water of post precipitation drained into mining area process water pipe network via sump and pumping equipment pipe.

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