CN1174281A

CN1174281A - Exploitation of placer mine by means of special tunnel and drainage method

Info

Publication number: CN1174281A
Application number: CN 97116616
Authority: CN
Inventors: 张朝喜
Original assignee: Individual
Current assignee: Individual
Priority date: 1997-08-04
Filing date: 1997-08-04
Publication date: 1998-02-25

Abstract

The present invention drains underground water in the water-bearing strara containing rich placer mine before exploitation. Washing dressing placer gold can obtain large gold grains. Natural gold grains with greater specific weight are buried in water-bearing grit layer, lower bedrock and crack, so that the drainage engineering should reach down to bedrock. Constructing well and tunnel to block underground water in the direction perpendicular to underground water stream can realize the opencut or undrground exploitation of placer mine.

Description

Exploit gravel mine with special roadway in conjunction with the drainage method

The present invention relates to a kind of energy and exploit placer gold deposit drainage underground water method under river valley or the aquifer, terrace safely, efficiently, apace.

China and in the world other regional water systems four, Pyatyi tributary and Zhi Guzhong owing to the primary gold ore bed and contain banket stone through weathering, degrade, under alluviation, proluvial transportation, depositional phenomenon take place.Formed at the settling sand gold deposit of northern China based on river valley placer gold deposit and southern river valley, terrace placer gold deposit.Broaden or all be that lateral enrichment is more and form industry and can adopt alluvial gold mine in the convex bank that turns round of gold dust enrichment rich position, particularly river by wide location that narrows down and leading edge position, terrace by narrow at river surface.Thicker because of natural primary goldc grains, being generally particle diameter is 0.2-1mm, and more than the big person 27mm, proportion heavily is 19.37 than other metals, generally is deposited in the gravel aquifer, on bottom or the bedrock surface and under the aquifer in the crack, basement rock top.

In present existing technology, placer gold deposit under exploitation river valley, riverbed, terrace or other the regional aquifers, (gold dredger or excavator are peeled off in general employing in the open, dump truck) sand gravel of gravel mine top is carried out the gravel mine hole with machinery or manpower method, the underground water that comes together in the open-air pit for gushing out then takes to cheat the arrangement water pump in the open, discharges the outer gold dust of gathering then in hole with mechanical means.Method for the underground mining gold dust, then be in recovery well, the draining water pump is set, the underground water that comes together in the shaft bottom is discharged outside the well, these two kinds of methods, still can not play the precipitation effect in the aquifer of super 100m/d for the groundwater seepage coefficient, but for the big flood placer gold deposit that be rich in water layer of groundwater seepage coefficient greater than 100m/d, exploit in this way that gold dust be difficult to carry out often, this is because for the prolongation of strip mining transformation along with the openwork time, the opencut pit area increases the degree of depth gradually and deepens, underground water is to open-air hole side slope pressure, because of flow action, will cause open-air hole side slope unstability, formation creeping motion type landslide, the open slope sand gravel, other Tu Yan and water form mud-rock flow and pour into fast in the open-air hole with the landslide form rapidly, its rapid degree often makes personnel and plant equipment also have little time rut and falls back on safety area outside the open-air hole, cause personnel's injures and deaths and burying of plant equipment, suffer heavy losses, if underground mining, abundant underground water will make and be increased to many water pumps in the well and also drain endless, if the construction of forced drainage recovery well on earth, the work of exploitation gold dust also is very difficult, also can cause the down-hole landslide simultaneously, roof fall, the accident of water logging gold mining work plane, though increase many drainage plant, also of no avail, cause time-consuming loss and waste huge, finally must abandon.Therefore, must at first carry out the measure of precipitation drainage, just drainage reduces in the aquifer of placer gold deposit underground water and can reach and exploit this purpose of gold dust safely and fast in advance in order to guarantee to exploit safely and efficiently the following placer gold deposit in river valley or gravel aquifer, terrace.

The purpose of this invention is to provide a kind of roadway associated methods underground water in sandy gravel stratum and other aquifers on the drainage placer gold deposit in advance, stop groundwater seepage and flow into the placer gold deposit internal channel.

The present invention realizes like this, on placer gold deposit in the Quaternary system gravel aquifer in the scope of ground, along the periphery, mineral deposit or the riverbed upstream and downstream perpendicular to current direction, (10-300 rice) construction a bite heavy caliber drainage precipitation well at a certain distance, this well productive life only is a drainage precipitation usefulness, and the degree of depth of each drainage well all will arrive the aquifer base plate until basement rock.After all drainage wells of every side all arrived basement rock, in the drainage well, two directions laterally connected in the tunnelling mode about every precipitation well, and all communicate through river valley, riverbed two bank basement rock water barriers of every well forms precipitation drainage well, row.In order to reach the purpose that stops underground water, roadway floor and bedrock surface elevation will be selected suitable position, can be near bedrock surface, also can be higher than the bedrock surface certain distance, as long as reach the purpose that stops underground water, guarantee the anhydrous or few water of gold mining work plane, not influence the purpose of safe gold mining.In order to guarantee the purpose of the rapid precipitation of drainage well, realize the precipitation funnel curve of mitigation, the borehole wall of all precipitation drainage wells will be built by laying bricks or stones with material that can infiltration, can use plank, timber also can be used cement bonded sand fistulae prefabricated component, and porose steel pipe, work stone or other materials are built by laying bricks or stones, which kind of material all must guarantee the hole of well bore wall this purpose that seeps water, and can not be fully closed.Consider speed of application and economical and practical, well bore wall and underworkings preferably adopt plank, timber to do wooden support.In containing the more stratum of fine sand or soil layer, in order to prevent to gush hourglass soil, available straw bag and other seepage material are lived at the plank periphery ring, to guarantee that only sand is not leaked in infiltration.Placer gold deposit groundwater seepage coefficient for especially big water reaches more than the 300m/d, article one, the drainage well lane engineering can not stop underground water fully, reach anhydrous or few water in the placer gold deposit, can respectively construct at riverbed upstream and downstream two places two or many drainage wells, lane engineering, it can be the plum blossom shape that big well location is put arrangement, the geese flying in a line-brothers shape.

The flowing water position is arranged in the riverbed, as required, flowing water can be changed its course in the riverbed or do not change its course, but in the gold mining manufacturing process, for safety, fast for the purpose of, must at first exploit the riverbed transfer from a distance than river, promptly near riverbed or edge, river valley, then gradually near river., inside and outside safety is subsided the scope at angle, during the exploitation gold dust, adopt water proof material filling dead zone in distance flowing water section the most nearby, with the crack that prevents roof fall arrive the face of land, river flows into the down-hole along the crack, jeopardizes safe gold mining production.Strip mining transformation gold dust method also is to gather earlier apart from the river farthest, and back far away earlier is near, moves closer to river, and casting is row back in the goaf, the close position, riverbank in the hole, goaf of river being changed its course in the open at last in the open.

Concrete enforcement of the present invention is provided by accompanying drawing

Fig. 1 is the example of the water system plan view of China's placer gold deposit in south

Fig. 2 is the localized mass section topographic map of middle placer gold deposit water system shown in Figure 1

Fig. 3 is the localized mass section log sheet of the gold dust casting bed shown in Fig. 1

Fig. 4 is the placer gold deposit control underground water precipitation funnel curve map shown in the figure.

In the plan view of the placer gold deposit ground of Fig. 1 description water system, it is by road 1, contains gold dust water system river 2, contains gold dust piece section geographical position 3.This position, town, district 4 and two, the three grades of water systems 5 that connect main rivers are formed, and scale is 1 to 500 ten thousand/.

Fig. 2 be the expression placer gold deposit localized mass section plane topographic map in it is an effluent dike 1, in the riverbed horizontally-arranged intercept water drainage well 2,2 ', geological prospecting borehole 3,3 ', the left and right sides and bottom topographic contour 4 among the figure, contain placer gold deposit position 5, the steep bank of riverbed two sides, dike bank 6, compositions such as river and flow direction signal mark 7, scale is 1/1st to 2000.

Fig. 3 placer gold deposit control well lane in conjunction with log sheet in, it is an effluent bed 1, alluvial deposits gravel aquifer 2, and the river that flowing in this section riverbed 3 it increase to some extent or reduce with season and this area's climatic influences, this water flows toward the downstream and finally injects great rivers, flow to the ocean, it is the main water source that replenishes underground water, in the riverbed, gold dust layer 4 in bottom and bedrock surface and the basement rock crack, for preventing and treating phreatic drainage well 5, it is containing on the placer gold deposit, respectively there are two rows in the downstream or arrange the drainage well more, every row several mouthfuls of drainage wells of all constructing, it is by phreatic transmission coefficient for well array and well spacing, drainage well yield and deciding, this well is being exploited the later stage also as gold mining roadway dual-purpose at one stroke, dewatering drift 6 quantity can be decided with drainage well quantity, it is directly constructed in drainage down-hole portion, near or go deep into basement rock, it is the passage that mainly intercepts water that the drainage roadway connects, and its dewatering effect is remarkable, its cross dimensions, can determine to be foundation in general because of this area's underground water water yield can guarantee conveniently that the constructor freely comes in and goes out, can be 0.5-5 rice, profile position can move towards construction with the basement rock elevation, and the tunnel will be perpendicular to phreatic flow direction construction.Bottom, riverbed basement rock 7 is enrichment place of natural primary gold bullion on its bedrock surface and the crack, and riverbed and alluvial gold ore body width are that tens of rice arrive hundreds of rice, and thickness does not wait from several meters to tens of rice.Fig. 3 scale cross section is 1/1st to 5000, and vertical section is 1/1st to 1000.

In Fig. 4 precipitation funnel curve map, primitive nature groundwater level line 1, drop to drainage phreatic line 2,2 ' be that underground water is through on the riverbed, the vertical section waterline behind the roadway drainage dams in the downstream, the restriction of the length distance that it does not dam with the riverbed upstream and downstream, and with the density and the groundwater seepage coefficient of the well lane engineering of damming, water yield is relevant, therefore consider the permission of economic benefit and technical condition, can adopt the distance 3 of damming in the placer gold deposit in industry, 3 ' location is longer as far as possible, examine annual summer because of belonging to high temperature rainy season, flood season, the riverbed water surface goes up, and influence the carrying out of gold mining work, is dry season in every year so be suitable for gold mining production, before the May in 1 year, amounted to 6 months time after i.e. October then, therefore, 3,3 ' distance should be selected the length of better economical rationality, is generally 50-5000 rice according to the length in mineral deposit and is advisable, if placer gold deposit is bigger, also can rise on the ten thousand metres.For underground water in the comparatively thorough drainage goldfield, infiltrating the underground water of supply through river in the remaining head behind the well lane engineering stream and this upstream and downstream interception area 3, in 3 ' section can install water pump by the gold mining well and discharge outside the well, reduce remaining head in the work plane as much as possible, reach the purpose of safe working gold dust, drainage roadway 3,3 ' consider is economical and practical preferably to adopt wooden support to be convenient to like this safeguard and reduce investment outlay.When using wooden support, hole diameter can be square, rectangle or garden shape, hole diameter will be come in and gone out and promote with the convenient construction personnel need be for adopting the close supporting of plank, or face mutually and the middle slit greatly of staying of plank, around the peripheral close gravel aquifer of plate, centre surround with other materials that can seep water such as porose iron plate or straw bags, can play the infiltration effect, the through shaft bottom of well depth basement rock, the borehole wall also can adopt concrete prefabricated hourglass pipe, this tube wall inner pore is a penetrating passage, and preparation method is that cement adds and smashes in addition the fritter rubble and add water and stir and make.Riverbed 4 has current to pass through in the river bed than the bottom, this also be dam the distance interior river recharge of phreatic water main water source, infiltrate increment in order to reduce river, should take necessary control measures, under the situation that one of method is not dark at water level or flow velocity is less, clay and other comparatively economic materials are filled out in the river bed, form the river bed water barrier, or select comparatively suitable position that river is changed its course in the riverbed.Gold dust ore bed 5 is general in the middle and lower part of underground reservoir, and on the bedrock surface and the basement rock crack, this also is the main cause that must prevent and treat underground water.So it is more or less freely that basement rock 6 is generally harder rock gold mining on bedrock surface, boring when geological prospecting borehole 7 is geological prospecting gold dust ore bed, be generally to geologic prospecting and scrutinize and look for ore deposit boring, extract from boring that core is separable to go out gold bullion and sample ore is to grasp the main foundation that gold dust buries reserves and rule thereof.Scale is that the vertical section is 1: 10000/one, and perpendicular cuing open is 1/1st to 1000.

For fear of influence in many unfavorable factors such as gold mining area, climate, landform, prolong the annual gold mining phase, the control ground water engineering can be peeled off engineering or well with the mining hole, open-air hole of gathering gold dust and adopt development engineering and can carry out synchronously, and the well lane engineering of control underground water drainage is carried out a little in advance.

In order to guarantee safe gold mining, guarantee to prevent and treat carrying out smoothly of ground water engineering, in gold dust exploitation workspace, to guarantee the supply of power supply, method is to connect two tunnel high voltage sourcies simultaneously, one the tunnel is working power, one the tunnel is standby electric power, or one tunnel high voltage source, purchases generating set as standby electric power in addition.

Claims

1, in the aquifer in river valley and terrace placer gold deposit, in bottom and bedrock surface thereof and the basement rock crack, some location is the more position of placer gold deposit enrichment and become industry and can adopt alluvial gold mine, in order to prevent phreatic dynamic pressure, cause open-air hole mining face slope and land slide, the roof fall accident of landslide and lane, down-hole mining face jeopardizes machinery and personal safety, so phreatic precipitation technical measures in the drainage of the reduction in advance placer gold deposit that must carry out, its method is along on riverbed, terrace or the river valley, the downstream is perpendicular to current direction, or riverbed two sides, beat the big well of the special drainage of a bite at a certain distance, the degree of depth basement rock that goes directly, in the bottom, aquifer by near or go deep into the basement rock place underworkings of laterally constructing and link the through two sides of all drainage wells water barrier, it is characterized in that the big well of all drainages [5] all is connected with underworkings [6] communicates, up to the riverbed, terrace or water barrier position, two sides, river valley, with interception underground water, reach the phreatic purpose of drainage in advance.

2, according to claim 1, the drainage roadway all should be provided with at placer gold deposit upstream [3], two places, position, downstream [3 '], tackles upstream and downstream underground water with this.

3, according to claim 1, the phreatic drainage roadway of placer gold deposit upstream [3], downstream [3 '] interception, row are at a distance of being advisable with 30-5000 rice, and be bigger as the ore deposit gold deposit, can suitably increase distance for ten thousand metres or more than the ten thousand metres.

4, according to claim 1, the big well of special drainage [3], [3 '] vertical concentration should arrive placer gold deposit aquifer base plate bedrock surface or go deep into basement rock, and well spacing is not limit, can far can be near, and as required to be advisable in the 10-300 rice.

5, according to claim 1, perpendicular to the underflow direction, the basement rock of through two sides, riverbed water barrier, roadway floor elevation are on bedrock surface or go deep into basement rock in the aquifer for dewatering drift [6] construction.

6, according to claim 1, drainage dam underground water well, lane engineering in downstream, upstream, riverbed [3] [3 '] can be each row of upstream and downstream, two rows or many rows.

7, according to claim 1, drainage underground water well, lane engineering [3], [3 '] can be adopted placer gold deposit and open-air hole with the riverbed well and adopt that gold dust is peeled off engineering construction synchronously or drainage, well lane engineering is constructed in advance.

8, according to claim 1, drainage well, lane engineering [3], [3 '] can be in upstream and downstream, placer gold deposit aquifer perpendicular to groundwater flow direction and riverbed or the constructions of both sides, river valley, be connected with underworkings from ground, inclined gallery can be used as discharge pipe line and lay passage and personnel's material access.

9, according to claim 1, the big well of special drainage [3], [3 '] well depth can reach 50-300 rice, and the well head shape can be a square, garden shape or rectangle, its diameter or the length of side are 0.5-6 rice, dewatering drift [6] width and highly be 0.5-5 rice, and the tunnel gradient is along bedrock surface height relief or arbitrary shape.

10, according to claim 1, the big wells of all special drainages [5] shaft cladding preferably adopts plank, timber, also can use concrete prefabricated soakaway trench, steel pipe and other materials, dewatering drift [6] material generally all adopts timber to make support material, but all roadway materials must all be processed and construct the pit shaft borehole wall tunnel that can seep water, as making well bore wall with plank, the centre should be made cross with timber and support well bore wall, to strengthen stress, keeps well bore wall firm.