CN115584957A

CN115584957A - Method for mining salt lake mineral products in segmented and progressive linkage manner

Info

Publication number: CN115584957A
Application number: CN202211417584.3A
Authority: CN
Inventors: 吴蝉
Original assignee: Individual
Current assignee: Individual
Priority date: 2022-11-14
Filing date: 2022-11-14
Publication date: 2023-01-10
Anticipated expiration: 2042-11-14
Also published as: CN115584957B

Abstract

A method for mining salt lake mineral products in a segmented and progressive linkage mode comprises the steps of partitioning the segments in different regions, establishing a regional brine seepage field, mining brine and replenishing water at the periphery, and mining in a progressive linkage mode. Salt-forming original landforms and geological structures of salt lake mining areas are utilized to divide mining areas, sectionalized ore bodies and a one-by-one mining method, fine mining of salt lake mineral products is achieved, and further improvement and improvement of salt lake mining technical specifications and standards are facilitated; by sectionalized arrangement of salt lake mineral products, progressive linkage mining and partition rotation mining are adopted, and meanwhile, the mining of raw brine of the salt lake, the driving mining of brine in a residual salt mineral layer and the solution filtration mining of solid potassium mineral (substance) in the salt mineral layer are realized; through the drainage, driving and solution filtration tertiary mining and the partition repeated rotation type mining, the total extraction amount of the raw brine mine in the salt mine layer can be more than 95 percent, the solution filtration recovery rate of the solid potassium mine (mineral) can be more than 60 percent, the available resource amount of potassium, lithium and the like in the salt lake is improved, and the waste of the salt lake resource is avoided.

Description

Method for mining salt lake mineral products in segmented and progressive linkage manner

Technical Field

The invention relates to the technical field of mining, in particular to a method for mining salt lake minerals in a segmented and progressive linkage manner, which is particularly suitable for application of liquid lithium, potassium, boron and other minerals and symbiotic solid potassium salt minerals.

Background

Salt lake minerals include solid lyotropic salt minerals, liquid brine minerals, which are typically deposited in layers and co-formed together.

The solid soluble salt ore is mainly a mixed deposition ore layer of halite, sylvite and magnesium salt, and the deposition ore layer mainly of halite is mainly composed of halite self-shaped crystals with the particle size of 0.5-5 mm, generally contains 1-25% of silt and is in a loose, semi-loose or cemented state. The sedimentary mineral layers of potassium salt and magnesium salt are mainly distributed in the rock salt layer in a lamellar, lenticular or star-dispersed manner, so that a potassium easily-soluble salt mineral product, namely solid potassium mineral, is formed, and has no independent mining value at present, and is usually converted into liquid brine mineral for mining. The rock salt deposits the ore bed, the thickness is from less than 10cm to more than 5m, and the rock salt deposits the layer with different thickness salt-containing clay, silt and silt frequently and alternately.

Liquid brine mine is also called brine mine, is distributed in a rock salt deposition ore layer and is called intergranular brine, and is distributed in a silt layer and a sand layer and is called pore brine, so that surface water body is called lake surface brine. The liquid brine mine can be divided into a submersible type (also called submersible brine) and a pressure-bearing type (also called pressure-bearing brine) according to the occurrence state, and the hydraulic connection between the two types is weak. Lake surface brine is usually closely hydraulically connected with submerged brine, and the water quantity and the water quality are greatly influenced by seasonal supply of surface water. The buried depth of the water level of the latent brine is 0.2-1 m, the bottom boundary is generally less than 50m, and the latent brine is a water-containing layer which is formed by a plurality of layers of discontinuously distributed salt-containing clay, silt thin layers or lens bodies. The bearing brine is sealed underground, the upper covered water-resisting layer is a silt-containing clay layer, the thickness is more than 0.2m, the single-layer brine-containing salt layer is different from 10cm to more than 5m, the water-resisting layer and the brine-containing salt layer are in multilayer overlapping deposition, the salt grain size, the density and the water content of each salt layer are different from the bearing pressure of the brine, the bottom boundary is generally more than 20m to less than 400m, and the initial water level of the water-containing layer is a positive water level. The brine mine is rich in ions such as sodium, potassium, magnesium, lithium, boron, chlorine, sulfate radical and the like, and is a main object for mining salt lake minerals.

The brine resource amount of the brine mine is divided into porosity and water supply degree. Porosity refers to the amount of brine contained in the various pores, fissures, and holes in a unit layer of a halogenated water-bearing ore. The water supply degree refers to the amount of brine seeping from a salt bed under the action of gravity and natural hydrodynamic force in a unit halogenated water ore bed. Porosity and feedwater quality are generally considered as the amount of brine that can be produced, i.e., the amount of resources that can be produced. According to the measurement of the porosity and the water supply degree of the brine-containing salt layer, the water supply degree brine amount of the brine-containing salt layer is less than 60% of the porosity brine amount, theoretically, about 30-50% of brine ores can not flow out of pores under the condition of gravity and natural water power and are retained in the salt ore layer, and the supersaturated brine has the functions of crystallization under the strong evaporation and disturbance environment, brine mixing crystallization effect of doping of different brines and the like, so that the brine is retained in the salt layer or the fragment layer, and part or all of the crystals are converted into solids or are sealed in the gaps. Brine is dispersed in a rock salt layer or a clastic layer after being crystallized, and relative microelements such as lithium, potassium, boron and the like in the brine cannot meet corresponding grade requirements according to solid mineral product evaluation indexes, so that retained brine mineral products cannot be exploited, and the recoverable amount of the brine is reduced substantially in practice.

The scarcity of salt lake mineral products such as potassium, lithium and the like in China requires that salt lake resources are exploited and utilized finely. There are no relevant regulations and standards in the mining of salt lake resources.

At present, lake surface brine is mined by directly extracting brine, channel digging and pit engineering is mainly adopted for latent brine with the buried depth of less than 20m and pressure-bearing brine, well mining engineering is mainly adopted for brine with the buried depth of more than 20m, and brine flows out by gravity and is collected and extracted. The mining method can only mine the water supply reserve and the porosity brine retained in the salt mine layer, because the brine is dispersed in a rock salt layer or a clastic layer after being crystallized, and relative trace elements such as lithium, potassium, boron and the like in the brine cannot meet the grade requirement of mineral products according to the evaluation index of solid mineral products, so that the retained brine mineral products cannot be mined, the recoverable amount of the brine mine is actually greatly reduced and usually accounts for more than 40% of the total amount of the brine mine in the salt lake, and the recoverable reserve of resources is greatly reduced.

The above background description is provided to better explain the technical problems addressed by the present invention, and it is particularly stated that the related art described in the background of the invention by the applicant is not a general knowledge of those skilled in the art, and does not constitute a part of the prior art, wherein the related art is also one of the protection contents disclosed in the present invention.

Disclosure of Invention

The invention aims to improve the recovery rate of brine mine and simultaneously carry out solution filtration mining on solid potassium mine (substance) so as to realize the integrated mining of solid and liquid mine. The invention provides a method for mining salt lake mineral products in a segmented and progressive linkage manner, and aims to effectively improve the yield and efficiency of mining salt lake mineral resources.

The technical scheme adopted by the invention is as follows: a method for mining salt lake mineral products in a segmented and progressive linkage manner comprises the following steps:

s1, partitioning a block by regions:

according to the natural sedimentary landform and geological structure characteristics of the salt lake mining area and the geological exploration result, dividing a relatively independent mining area for mining according to the naturally distributed sedimentary depressed areas and the salt lake sedimentary law;

dividing a salt mine layer with large deposition thickness and deep burial depth into a central mining area according to geological and hydrogeological characteristics of salt mine deposition in the mining area, and dividing a plurality of peripheral mining areas at the periphery of the central mining area;

laying a brine mining well and a brine mining channel along the direction of a salt mine layer in divided mining areas, mainly laying a brine mining well in a central mining area, assisting the brine mining channel to form a brine mining well line, uncovering the whole salt mine layer to a bottom plate, mainly laying a brine mining channel in a peripheral mining area, assisting the brine mining well to form a brine mining channel system, uncovering a covering layer in the depth of the brine mining channel, a halogen-containing water salt mine layer and a water-resisting interlayer;

the brine mining well line and the brine mining canal system divide the salt deposit into a plurality of block sections with different shapes, and each block section is used as a mining unit;

the brine extracting well line and the brine extracting channel system are both used as passages for brine extracting in the early period and water replenishing in the later period, and a brine extracting-water replenishing project combining the brine extracting well line and the brine extracting channel system is formed; according to the requirements of mining planning, the water replenishing mode is sequentially and orderly developed from a peripheral mining area to a central mining area;

s2, establishing an area brine seepage field: in the mining process, the water level of brine is reduced along with the brine mining of the central mining area to form a water level falling funnel, and a hydrodynamic field for converging the brine in the brine-containing salt mine layer from the peripheral mining area to the central mining area is established;

s3, peripheral bittern collection and water supplement: after the falling funnel is formed, brine is mined from the edge part and the peripheral mining area of the falling funnel, a brine water level depression is locally formed, and make-up water is introduced into the water level depression for water supplement, so that the block section or a plurality of block sections form a certain water surface and serve as a continuous water supplement water source to raise the water level and increase the hydraulic gradient of the funnel, and the brine in the brine salt mine layer is promoted to flow to the central area of the funnel;

s4, progressive linkage mining: adopting a tertiary mining mode to carry out brine mining, adopting drainage type mining for primary brine mining to form a brine water level falling funnel in the whole area, and converging brine in a mining area to the center of the funnel; the secondary brine extraction adopts water supplement-brine removal drive type exploitation, the water head pressure is increased along with the introduction of the water supplement, and brine in the salt ore layer and the retained brine are driven to flow to the center of the falling funnel; the third brine extraction adopts the dissolution filtration type extraction of water supplement soluble ores, and the supplement water flows to the center from the periphery of the brine falling funnel so as to dissolve and filter the solid soluble salt ores in a dynamic mode of continuous seepage in a salt ore layer; linkage mining of continuous bittern mining of the central mining area and continuous bittern mining and water replenishing of the peripheral mining area is formed, and progressive mining of the whole mining area from the periphery to the center block by block is realized.

Further, in step S1, the brine mining-supplementing project includes laying brine mining wells, brine mining channels, brine conveying channels, and corresponding auxiliary facilities for brine pumping, brine conveying, water supplementing, power supplying, and pre-evaporation concentration of the salt pan in each mining area, so as to form a brine mining-supplementing-brine-driving-mineral dissolving integrated mining system composed of brine mining well lines, brine mining channel systems, brine conveying channel systems, and mining auxiliary facilities.

Further, in step S4, the mining step is that the central mining area is firstly mined, brine is mined and supplemented in the peripheral mining area after a brine water level falling funnel is formed; the water replenishing principle of the replenishing water is that the edge block of the mining area is gradually and continuously performed towards the central block; in order to fully guarantee the seepage and leaching time, the leaching type mining needs to carry out rotation type mining in a plurality of peripheral mining areas.

Further, in step S3, after the content of potassium, lithium, etc. in the brine is reduced due to the continuous supply of make-up water, the production requirements are met by pre-evaporation concentration in a solarized salt pan.

Preferably, the make-up water is prepared from salt lake peripheral river lake water by utilizing salt field waste sodium salt, potash fertilizer production tailings, tail liquid, surface salt shells and the like.

Preferably, the average content of potassium ions in the water block section of the make-up water needs to be monitored in the mining of the mining area, and when the average content of potassium ions in the brine is more than 2g/l, the brine is normally mined; when the average content of potassium ions in the brine is less than 2g/l, the mining of the block section is suspended.

Further, the central mining area may be on one side of the entire mining area, and the peripheral mining areas may be distributed in a sector or other different distribution patterns.

Preferably, the buried depth of the bottom boundary of the salt mine layer is more than 20m, the thickness of the salt mine layer is more than 0.5m, the brine mining mode is mainly arranged, the brine channel mining mode is assisted, and the brine mining well needs to penetrate through all the salt mine layer and the brine layer; the aperture of the brine extraction well is 500-1500mm, and the well depth is 3-6m below the bottom plate of the aquifer and is used as a settling section of the salt granule sediment; selectively discharging a strainer pipe or a bare hole and a hole protecting pipe under a well mouth according to the hydrogeology requirement according to different stratum structure and debris interlayers; when the deep well is submerged to the position 1-5m from the bottom boundary of the aquifer to pump brine, the thickness of the aquifer is large, and the buried depth of the bottom boundary is more than 50m, the pump can be lowered to the lower 2/3 of the well depth or below a stable water level according to the brine pumping intensity, and the position of the lower pump is adjusted along with the lowering of the water level.

Preferably, the bottom edge boundary burial depth of the salt ore layer is less than 20m, the thickness is more than 0.5m, a bittern-mining channel is mainly used, a bittern-mining well is used as an auxiliary, and the bittern-mining channel is required to be deep into or dig through the ore layer and the bittern-containing layer; the depth of the brine collecting channel is less than 20m, and the width of the channel bottom is 1-3m; the length of the brine extraction channel is the same as the length of a connecting line of the brine extraction well, and a brine extraction pump station is erected at one end or two ends or a suitable position of the brine extraction channel.

Preferably, in the solution filtration type mining, a mining mode of multi-region and partition rotation mining is implemented, the mining period is ensured to be the same, one brine mining region stops mining, other brine mining regions continue to normally mine brine, and the rotation mining interval period is more than 12 months/rotation.

The beneficial effects of the implementation of the invention are as follows: the invention relates to a mining system and a mining method for mineral products of a quaternary salt lake, wherein 33 modern salt lakes are distributed in a fadda basin, which is a centralized distribution area of the salt lakes in China. The invention combines the original landform, the structural characteristics of the salt lake and the geological exploration result of the salt lake mining area, realizes and promotes the refined exploitation and utilization of the salt lake mineral, and is beneficial to further perfecting and improving the technical specifications and standards of the salt lake exploitation; through the block arrangement of salt lake mineral products, progressive linkage mining is adopted, and zonal rotation type mining is adopted, so that the driving of brine in a salt mineral layer to a mining area in the water replenishing process is efficiently realized, the defect that brine cannot be mined due to the fact that brine is dispersed in a rock salt layer or a fragment layer after crystallization is avoided, and meanwhile, the leaching mining of solid potassium mineral (substance) is realized. By adopting the method, the total extraction quantity of the raw brine mine can be more than 95 percent and the leaching recovery rate of the solid potassium mine (substance) can be more than 60 percent through multiple circulating mining, thereby greatly avoiding the waste of salt lake resources.

Drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly described below, it is obvious that the drawings in the following description are only some embodiments of the present invention, and for those skilled in the art, other drawings can be obtained according to the drawings without creative efforts.

FIG. 1: a schematic plan view of the layout of the partitioning blocks in the bittern collecting engineering;

FIG. 2: and the sectional view of the partitioned blocks in the bittern collecting engineering is schematically shown.

Detailed Description

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

In the summary of the invention, for the convenience of understanding of those skilled in the art, the meanings of the technical names used therein are explained as follows:

a development unit: each original sedimentary pit or geological survey partition;

mining area: central mining area + peripheral mining area;

central mining area: in the ore body distribution area with thick ore layer and deep burial in the natural concave ground, a brine mining well is taken as a main area, and a brine mining channel is taken as an auxiliary area;

peripheral mining area: aiming at ore body buried shallow in the ore bed, the periphery of the central mining area is provided with a layout area which takes a brine mining channel as a main part and a brine mining well as an auxiliary part;

mining block section: the mining plot is divided by projects such as a brine mining well line, a brine mining channel and the like;

adopt steamed-moisturizing system: the engineering combination of the brine extracting well group and the brine extracting channel group has double functions of brine extracting and water replenishing;

mining-moisturizing unit: the block distribution range of the brine collection-water supplement system.

The embodiment of the invention comprises the following principle and mining method, please refer to fig. 1 and 2, in fig. 1, a central mining area and a peripheral mining area are divided according to the deposition center or thickness of a salt deposit, which mainly ensures that the brine is fully mined and is not necessarily connected with the position of the central mining area in the center of the mining area, the central mining area can be arranged on one side of the whole mining area, and the peripheral mining area can be distributed in a fan shape or other different modes. In the attached figure 2, after the brine is extracted from the brine extracting channel at the edge of each peripheral mining area, the brine level at the edge of the brine-containing water layer, the brine extracting channel and the brine levels at the two edges of the brine-containing water layer are reduced to present brine water level depression (see the edge of a cross section), and when the water level reaches the bottom of the channel, the supplementary water is introduced for supplementing water. When the content of potassium ions in the brine collected in the block section is less than 2g/l, the brine collection engineering is used as a water replenishing channel and the brine collection is carried out in the next block section. When the content of potassium ions in the peripheral mining area is less than 2g/l or the water level is recovered slowly and brine cannot be mined, the brine is temporarily mined in the peripheral mining area and is cyclically stopped, and the brine is continuously mined in other peripheral mining areas and the central mining area, so that the peripheral areas are periodically and cyclically mined, and the continuous mining in the whole area is ensured.

Each salt lake mine can divide the sedimentary concave land in the salt lake mining area according to the naturally distributed sedimentary concave land and the sedimentary rule of the salt lake, and can divide a geological exploration subarea, namely a natural unit in the form of the sedimentary concave land or the geological exploration subarea, by means of the geological exploration result. The sedimentary pit or geological exploration subarea is divided into a plurality of block sections with different shapes by arranging a brine-exploiting well group and a brine-exploiting canal system. In the divided mining area, the well and canal combined engineering is arranged, and the covering layer and the water-resisting interlayer of the haloid ore layer are uncovered to be used as a channel for early-stage bittern mining and later-stage water replenishing.

The salt and debris ore-containing layers of all the natural units are deposited and distributed horizontally or similar to the horizontal from the ground surface to the bottom plate, a plurality of salt-containing debris layers are clamped, the salt deposition thickness at the deposition center is large, the water-containing layer thickness is thick, the burial depth is deep, the salt deposition thickness gradually becomes thinner, forked or pinches off towards the periphery, and the burial gradually becomes shallow. Each natural unit may be used for mining as a relatively independent mining area. The salt deposit ore body with the accumulated thickness larger than 0.5m of the halogen-containing water layer group is regarded as the mining thickness, the solid potassium ore and the potassium ore in the salt ore layer are regarded as the soluble potassium filter, the ore-containing layer with the top boundary buried depth of 0-10 m of the ore body is mainly set to adopt the well mining mode to mine the brine, the ore-containing layer with the top boundary buried depth of 0-10 m of the ore body is mainly set to adopt the trench mining mode to mine the brine.

Typically, the central region of the deposit of natural units is selected as the central mining area and the peripheral region is selected as the peripheral mining area, around which a plurality of peripheral mining areas may be divided. The central mining area usually has large thickness of ore-bearing layer and deep burial depth, and mainly adopts a well mining mode and an auxiliary channel mining mode to intensively distribute a combination of a brine mining well group and a brine mining channel system. The peripheral mining area usually has small thickness of ore-bearing layer and shallow buried layer, mainly adopts canal mining and adopts well mining as assistance. Because the thickness of the salt bed and the burial depth are changed on the plane distribution, when the longitudinal thickness, the transverse thickness and the burial depth of the ore bed in the mining area are greatly changed, the well mining and the canal mining are alternately distributed according to the water level burial depth and the thickness of the ore bed, and the whole area can be a well mining area or the whole area can be a canal mining area under the special geological condition.

The bittern collecting wells and the bittern collecting channels in the mining area are all linearly arranged according to the trend of ore bodies to form various mining engineering combinations such as well lines + well lines, well lines + channels, channels + channels and the like, the range surrounded by the extension lines of each bittern collecting engineering forms a mining block section, and the mining block sections divided by the various bittern collecting engineering combinations form a mining block system of the full mining area.

After the central mining area brine mining engineering continues to mine brine until the water level drops, the mining area forms a brine water level descending funnel which takes the central mining area as the center and extends to the periphery, the hydraulic gradient of the brine in the stratum from the periphery to the center is artificially established, and a hydrodynamic field in which the brine converges from the periphery to the center of the mining area is formed.

After the mining area descending funnel is formed, brine on the edge of the peripheral mining area is mined, and water level depression is formed at the outer edge of the descending funnel, so that the water level is reduced, and the hydraulic gradient and the water pressure are reduced. When the bittern mining engineering can not continuously mine bittern, the bittern mining engineering can be converted into a water supplementing channel, prepared mineral solution is used as supplementing water to supplement water to a water level depression area, the water level of the edge of the funnel is improved, the water gradient and the water pressure are increased and maintained, retained bittern in a salt layer is squeezed, the dynamic balance of bittern mining and water supplementing is maintained to be always towards the bittern mining end of the central mining area, and the supplementing water is ensured to drive the retained bittern in the salt layer to flow towards the bittern mining end of the central mining area.

The make-up water continuously dissolves and filters solid potassium (salt) minerals when seeping in the salt deposit and moves to the center of the funnel together. When the potassium ion content of the brine in the block is less than 2g/l, the mining is suspended in the block, water replenishing is continued, a high water head is continuously maintained, the supplemented water continuously captures the brine and solid potassium minerals in the block, and water replenishing mining is performed on adjacent blocks, so that the stability of a full-open mining area descending funnel is maintained, the brine is continuously moved from a peripheral mining area to a central mining area, and the linkage brine mining in the whole area is ensured. According to the brine water level decline condition in the ore bed, this kind of moisturizing exploitation can be single block section, also can be that the polylith section goes on simultaneously, so impel in proper order, until the district of exploiting entirely.

The make-up water can be prepared by injecting waste sodium salt Tian Rongjie rock salt into river and lake water around a salt lake to prepare, dissolving production tailings (the main component is rock salt) and preparing surface salt shells, and the like, and can be prepared in various ways according to available conditions and the convenience of make-up water.

According to the distribution of water level falling funnels in the ore bed, a plurality of peripheral mining areas can be divided in different peripheral directions around the central mining area, so that a plurality of bittern mining-water supplementing systems consisting of the central mining area and the peripheral mining areas are formed, and each system can be used as a relatively independent mining-water supplementing unit. Because the mining intensity is greater than the flow rate of brine in the stratum and the speed of supplying water to drive brine and dissolve ores, a mining mode of peripheral mining area rotation type mining needs to be carried out, and the time of driving brine and dissolving ores is ensured. The salt lake brine mine and the solid potassium mine (material) can be fully extracted through multiple rotation type mining.

When the mining engineering is built in the mining area, the mining area and the mining engineering are simultaneously built for matching and public engineering such as brine mining, brine transportation, water supplement, power transmission, salt field turnover, water supplement preparation and the like.

The mineral products of all the sections of the mining area are mainly developed by adopting a brine mining well and a brine mining channel.

The buried depth of the bottom boundary of the ore-bearing layer is more than 20m, the thickness is more than 0.5m, the well mining mode is mainly used, the canal mining mode is assisted, and the brine mining well must penetrate through all the salt ore layers and the halogen-bearing water layers. The aperture of the brine extracting well is 500-1500mm, and the well depth is 3-6m below the bottom plate of the aquifer, and the well is used as a sediment section of the salt granule. According to different stratum structure and debris interlayer, selectively arranging a strainer pipe or a bare hole and a hole protecting pipe under a well mouth according to hydrogeology requirements.

After the well is formed, the deep well is submerged by the pump to a position 1-5m away from the bottom boundary of the aquifer to pump brine, the thickness of the aquifer is large, and when the buried depth of the bottom boundary is more than 50m, the pump can be lowered to the lower 2/3 of the well depth or selected below a stable water level according to the brine pumping intensity, and the position of the pump is adjusted along with the lowering of the water level. The bittern collecting wells are distributed along the direction of the mineral-bearing stratum to form a bittern collecting well group, the well spacing is 50 m-300 m, the line spacing is 100 m-500 m, and the length and the width of the well mining area are determined by salt deposition, the burial depth of the bittern layer group and the plane spread. When the distribution area of the area in the natural unit of the salt lake is large, a large-area well mining area can be formed after the well mining lines are continuously arranged, and the water level burial depth of the bottom boundary of the water-bearing layer is less than 20m and is a well mining boundary.

The bottom boundary of the ore-bearing layer is buried to a depth less than 20m, the thickness is more than 0.5m, channel mining is mainly used, well mining is assisted, and the bittern-mining channel is deep into or digs through the ore-bearing layer and the bittern-bearing layer. The depth of the brine mining channel is less than 20m, the width of the channel bottom is 1-3m, the width of the channel opening is different due to different slope stability of the salt deposit, and is determined according to the specification, generally more than 20m, the channel spacing is 100 m-less than 500m, and the length of the brine mining channel is the same as the length of a connecting line of a brine mining well. And (3) erecting a brine extraction pump station at one end or two ends or suitable positions of the channel, and selecting a mixed flow pump to pump brine according to the water quantity.

The width of each single block section in the mining area is less than 500m, the depth is the bottom boundary of the ore bed or the depth of the mining engineering, and the part of the salt mine below the depth of the mining engineering is driven by the edge water supplement close to the bottom or driven by the water supplement of the brine mining well. The length of the mining block is equal to the length of a brine mining well line and a brine mining channel, and the mining block covers a full mining area.

The mine is provided with a plurality of sedimentary depressed areas or geological exploration subareas, and each sedimentary depressed area and each geological exploration subarea are relatively independent development units and can be orderly exploited according to the mine development plan.

Aiming at a mining area where salt lake brine and solid mineral products coexist, three mining modes of drainage, driving and solution filtration are adopted as the technical scheme for mining of each independent development unit according to the characteristics of taking liquid as a main material and mutual conversion of solid mineral products and liquid mineral products.

And (5) draining and exploiting. And selecting areas with large thickness and stable distribution of salt and water-bearing layers in the central mining area, constructing brine mining wells and channel groups, mining after a well and channel mining line is built, and continuously extracting brine. Through continuous brine mining, the brine level in each block section of the central mining area descends to form a descending funnel, and the descending funnel is gradually deepened and enlarged. The center of the brine falling funnel forms a hydraulic gradient with the periphery. Continuously extract brine, constantly increase, deepen brine descending funnel, the water conservancy slope constantly increases also, brine increases to descending funnel center flowing pressure in the halogenated water layer, promotes the brine flow direction and adopts the steamed end to artificially establish underground brine by the peripheral hydrodynamic field that flows to the center of funnel, guaranteed that brine in each block section migrates to the funnel center. The exploitation of the brine at the stage is a drainage type exploitation, the structures of the stratums containing the brine are different, the amount of the brine is different, and the total amount of the brine in the ore stratums containing the brine is generally 40-50%.

And driving the mining. And after dredging and dry mining until the brine water level of the central mining area generally drops to a position which is more than 1/3 of the original water level, laying a brine mining channel and a well group in the peripheral parallel or vertical central mining area of the peripheral mining area falling funnel until the zero boundary of the ore bed. And (4) overlapping and collecting brine on the water level surface at the edge of the falling funnel. By continuously collecting the brine, a "water level depression" zone is formed on the dropping funnel. The water level of the brine extraction channel and the brine extraction well generally drops, or when the water level of the brine extraction channel and the brine extraction well bottom is reached, the brine extraction channel and the brine extraction well are used as water replenishing channels, water replenishing is introduced, a water head is increased, the pressure of brine in a brine layer is increased, and brine in a brine layer and unexplored brine in a retention section are driven to move to a brine extraction end in the center of a funnel. The mining of the brine at the stage is driven mining, and the total amount of the brine in the brine-containing ore layer can be generally mined by 20-30 percent.

And (5) leaching and exploiting. When the average potassium ion content of the brine collected in the block section is less than 2g/l, the block section is suspended for brine collection, make-up water is continuously introduced into a brine collection channel or a brine collection well, a seepage-leaching field is formed in a descending funnel from the side of the make-up water to a brine collection end, and the make-up water flows through the block section to perform dynamic ore dissolution. And dissolving the residual brine, solid potassium ore and potassium minerals in a scattered manner in the stratum while continuously recovering the water level of the goaf, and recovering the brine when the average potassium ion content of the brine in the block section is more than 2 g/l. The brine mining at the stage is leaching mining. Through multiple circulation mining and combined drainage and driving mining, the total extraction amount of the raw brine mine can be more than 95 percent, and the dissolution filtration recovery rate of the solid potassium mine (substance) can be more than 60 percent.

Dissolving filtration and rotation mining. The dissolution filtration of solid potassium in dissolution filtration mining is a dynamic seepage-dissolution filtration cycle process, which needs to be continuously carried out until the hydraulic gradient is gradually reduced and the water level is gradually recovered, so as to avoid the phenomenon that solid potassium minerals cannot be fully dissolved and filtered due to water leakage shortcuts caused by various natural channels in the stratum. The water supplement during solution filtration type mining and driving type mining is continuous, and the water supplement during driving type mining starts to perform solution filtration on solid potassium minerals. Because the specific gravity of the make-up water is small, the make-up water can float on the original brine after contacting the original brine, and no mixing space exists in the stratum, so that the make-up water is in end-to-end contact with the original brine in the stratum, the seepage paths are basically consistent, the make-up water is lack of potassium, and the make-up water is dissolved into a liquid phase when encountering potassium minerals in the seepage process, thereby achieving the purpose of exploiting solid potassium. The difference lies in that the bittern collecting end is used for continuously collecting bittern during driving type mining, and the collected bittern is raw bittern during deposition and mining. During solution filtration type exploitation, the brine extraction end intermittently extracts brine. When the extraction is stopped, the water level of the make-up water is gradually recovered in a seepage-solution filtration mode. The whole water replenishing-seepage-leaching process is a process of mixing the replenishing water with salt mineral solutions such as residual raw brine, dissolved sodium potassium and the like in a salt layer to form high-potassium-content regenerated brine, and the raw brine is replaced by the regenerated brine.

And a plurality of peripheral mining areas are arranged on the periphery of the central mining area, a solution-filtration type mining stage is entered, a mining mode of multi-area and partition rotation mining is implemented, the mining synchronization is ensured, one bittern mining area stops mining, other bittern mining areas continue to normally mine bittern, the rotation mining interval period is more than 12 months/rotation, and when the average content of potassium ions in the bittern is more than 2g/l, the bittern is mined again. And (4) by multiple rotation mining, after the content of potassium ions in brine in the blocks is generally lower than 2g/l, the mining of each block in the brine mining area is finished.

The development sequence of each mining block section in the mining area is sequentially carried out from the edge to the center, so that the mineral development of the mining area is ensured to be orderly and efficiently utilized from the edge to the center, from the thin to the thick of a mineral layer and from the lean to the rich.

Make-up water is prepared and utilized. The method is characterized by being prepared by injecting waste sodium salt Tian Rongjie full of rock salt deposition into river and lake water around a mining area, preparing production tailings (the main component is the rock salt) and waste liquid with natural river and lake water, and preparing surface salt shells by dissolving the natural river and lake water, wherein various modes are selected according to available conditions and water replenishing convenience. The main indexes of the water preparation liquid for supplementing water are the degree of mineralization and the content of sodium ions, the degree of mineralization is 100-280g/l, and the content of sodium ions is 40-80g/l. The salinity and the sodium ion content can be selected according to the structural structure of a brine-containing salt layer and the conditions of overlying production and living facilities, the salt layer is compact and generally uses the supply water with lower salinity and sodium ion content, the supply water with higher salinity and sodium ion content is generally used in the early stage of supply, the stone salt framework is prevented from being damaged, and the supply water with higher salinity and sodium ion content is required to be adopted in the area needing to control ground collapse due to the long supply path of the supply water and the long time for dissolving and filtering the salt layer in the middle and later stages of supply.

The above description is only for the purpose of illustrating the preferred embodiments of the present invention and is not to be construed as limiting the invention, and any modifications, equivalents, improvements and the like that fall within the spirit and principle of the present invention are intended to be included therein.

Claims

1. A method for mining salt lake mineral products in a segmented and progressive linkage manner is characterized by comprising the following steps:

s1, partitioning a block by regions:

laying a brine mining well and a brine mining channel along the direction of a salt mine layer in divided mining areas, laying a brine mining well in a central mining area as a main part, laying a brine mining channel as an auxiliary part to form a brine mining well line, uncovering the whole salt mine layer to a bottom plate, laying a brine mining channel in a peripheral mining area as a main part, and uncovering a covering layer, a brine-bearing salt mine layer and a water-resisting interlayer in the depth of the brine mining channel by taking the brine mining well as the auxiliary part to form a brine mining channel system;

s2, establishing an area brine seepage field: during mining, the water level of the brine is reduced along with the brine mining of the central mining area to form a water level falling funnel, and a hydrodynamic field for converging the brine in the brine-containing water salt mine layer from the peripheral mining area to the central mining area is established;

s3, peripheral bittern collection and water supplement: after the falling funnel is formed, brine is mined in the edge part and the peripheral mining area of the falling funnel, brine water level depression is formed locally, make-up water is introduced into the water level depression for water supplement, so that a certain water surface is formed by the block section or the plurality of block sections, and the block sections are used as a continuous water supplement water source to lift the water level and increase the hydraulic gradient of the funnel, so that the brine in the brine salt ore layer is promoted to flow to the central area of the funnel;

2. The method according to claim 1, wherein in step S1, the brine extraction-water replenishment project includes laying brine extraction wells, brine extraction channels, brine transportation channels and corresponding brine extraction, brine transportation, water replenishment, power supply and pre-evaporation concentrated salt field extraction auxiliary facilities in each mining area, so as to form a brine extraction-water replenishment-brine removal-mineral dissolution integrated mining system consisting of a brine extraction well line, a brine extraction channel system, a brine transportation channel system and a mining auxiliary facility.

3. The method for mining salt lake mineral products in a segmented and progressive linkage manner according to claim 1, wherein in the step S4, the mining step comprises the steps of mining the central mining area, forming a brine water level dropping funnel, and then mining brine and replenishing water in the peripheral mining area; the water replenishing principle of the replenishing water is that the edge block of the mining area is gradually and continuously performed towards the central block; in order to fully guarantee the seepage and leaching time, the leaching type mining needs to carry out rotation type mining in a plurality of peripheral mining areas.

4. The method for mining salt lake mineral products in a segmented and progressive linkage manner according to claim 1, wherein in the step S3, after the content of potassium, lithium and the like in the brine is reduced due to continuous supply of the make-up water, the production requirement is met by pre-evaporating and concentrating the brine through a solarized salt pan.

5. The method for mining salt lake mineral products in a segmented and progressive linkage manner according to any one of claims 1 to 4, wherein the makeup water is prepared with salt pan waste sodium salt, potash fertilizer production tailings, tail liquid, surface salt shells and the like and the river lake water at the periphery of the salt lake.

6. The method for segmented progressive linked mining of mineral products in salt lake according to claim 5, wherein the average content of potassium ions in the supplementary water block is monitored in the mining area, and when the average content of potassium ions in the brine is more than 2g/l, the brine is normally mined; when the average content of potassium ions in the brine is less than 2g/l, the mining of the block section is suspended.

7. The method for mining salt lake mineral products in a segmented and progressive linkage manner according to claim 6, wherein the central mining area can be arranged on one side of the whole mining area, and the peripheral mining areas can be distributed in a fan shape or other different distribution manners.

8. The method for segmented and progressive linked mining of salt lake mineral products according to claim 6, wherein the burial depth of the bottom boundary of the salt lake is more than 20m, the thickness is more than 0.5m, the bittern mining mode is mainly distributed, the bittern mining mode is assisted, and the bittern mining well must penetrate through all the salt lake layer and the bittern-containing layer; the aperture of the brine extraction well is 500-1500mm, and the well depth is 3-6m below the bottom plate of the aquifer and is used as a settling section of the salt granule sediment; selectively discharging a strainer pipe or a bare hole and a hole protecting pipe under a well mouth according to the hydrogeology requirement according to different stratum structure and debris interlayers; when the deep well is submerged to the position 1-5m from the bottom boundary of the aquifer to pump brine, the thickness of the aquifer is large, and the buried depth of the bottom boundary is more than 50m, the pump can be lowered to the lower 2/3 of the well depth or below a stable water level according to the brine pumping intensity, and the position of the lower pump is adjusted along with the lowering of the water level.

9. The method for segmented progressive linked mining of mineral products in salt lake according to claim 6, wherein the buried depth of the bottom boundary of the salt mineral layer is less than 20m, the thickness is more than 0.5m, the main part is a brine mining channel, the auxiliary part is a brine mining well, and the brine mining channel is deep into or through the mineral layer and the brine layer; the depth of the brine collecting channel is less than 20m, and the width of the channel bottom is 1-3m; the length of the brine extraction channel is the same as the length of a connecting line of the brine extraction well, and a brine extraction pump station is erected at one end or two ends or a suitable position of the brine extraction channel.

10. The method for mining salt lake mineral products in a segmented and progressive linkage manner according to claim 6, wherein in the solution filtration type mining, a mining mode of multi-region and partition rotation type mining is implemented, the mining synchronization is ensured, one bittern mining area stops mining, other bittern mining areas continue to normally mine bittern, and the rotation type mining interval period is more than 12 months/rotation.