CN111661857A - Floating type salt sunning, photoelectric heating and continuous countercurrent floating heat exchange extraction of lithium concentrate - Google Patents

Abstract

The high-energy battery is an important carrier for realizing energy-saving and environment-friendly new energy and improving ecology by human beings, the lithium battery plays the most important mission in a long time in the future, and lithium resources in the lithium battery occupy the most core position; the Tibet salt lake has 30 percent of lithium resources in China, high concentration, small magnesium/lithium ratio, excellent wind and light resources, huge natural evaporation capacity, lack of energy and mineral resources and is very suitable for solar salt extraction; however, the civil salt solarization pond has the disadvantages of high cost, easy damage, difficult repair, insufficient technical energy extraction and the like, and the productivity is always low. The downstream high-speed development requires continuous and drastic increase of lithium resources, and about 80 percent of China is forced to rely on imports. The floating type solar salt drying, photoelectric heating and continuous countercurrent floating heat exchange lithium concentrate extraction large-scale lithium extraction system technology is provided, clean light, electric heating temperature rise, crystallization lithium precipitation are used, natural evaporation crystallization lithium precipitation and process lithium washing are matched, and the new breakthrough of solar salt extraction lithium concentrate capacity is realized.

Description

Floating type salt sunning, photoelectric heating and continuous countercurrent floating heat exchange extraction of lithium concentrate

Technical Field

This patent is used for the salt lake salt that shines to draw fields such as lithium carbonate concentrate, also can be used to other concentrates, carry the salt field to and adopt heat transfer, heating intensification place for realizing other purposes.

Background

80% of lithium resources in China are in Qinghai-Tibet plateau, and most of lithium resources are dissolved in salt lake; the good salt lake in Tibet is mostly in the area with the altitude of 4000+300m, the large-scale construction is not suitable due to factors such as high altitude, cold nature in freezing in the ground, thin air and the like, the Tibet also has no coal, petroleum and natural gas mineral resources, the annual wind power is large, the sunshine time is long, particularly in the region of the Aries enriched in the salt lake, the annual evaporation capacity is about 2300mm, the annual rainfall is extremely small about 150-180 mm, the attribute magnesium/lithium of the salt lake resource of the Tibet is very small, and the salt lake directly contains lithium carbonate and the like, in a word: is particularly suitable for extracting lithium salt by solar salt (in the text, lithium extraction, lithium salt extraction and lithium concentrate are all used for extracting lithium salt, are target products and only have different purities).

The principle of extracting lithium from salt lake by drying salt (and extracting lithium from many ore factories) is as follows: the solubility of Li2CO3 decreases with increasing temperature, as in fig. 1, and the solubility of other heterosalts increases with increasing temperature, as in fig. 2, 3, and vice versa; heating the brine to raise the temperature, crystallizing to separate out lithium salt precipitate, dissolving other miscellaneous salts in the brine, and performing solid-liquid separation to obtain the lithium salt.

The method is characterized in that salt is sun-dried in a Tibet salt lake to extract lithium salt, large-scale development is carried out for a long time, an energy-saving and environment-friendly solar heat collection greenhouse is also used in production, but due to the fact that civil construction salt sunning ponds are high in manufacturing cost, serious in damage during operation and difficult to repair, and the energy with huge demand cannot be collected by the existing process technology, the lithium salt cannot be produced in a large scale in an actual production link.

Disclosure of Invention

The method is generally divided into three blocks according to the characteristics of the process flow, namely a high-temperature lithium extraction zone, a medium-temperature heat exchange zone and a low-temperature (normal temperature) storage zone, and liquid flows in all production processes flow in reverse directions to exchange heat efficiently; scientific planning, reasonable layout and elaborate construction are required to ensure smooth implementation, as shown in fig. 4 and 5;

1.) high temperature lithium extraction zone: heating brine (resistance heating, sunlight heating, microwave heating and bottom high-temperature backflow water heating) to raise the temperature, crystallizing and separating out lithium salt (short for crystallization and lithium separation), dissolving miscellaneous salt by high-temperature water, and finely washing specially-thrown lithium crude salt into lithium concentrate;

2.) medium temperature heat exchange zone: the brine supply pipe and the return water have larger temperature difference, heat exchange is fully carried out in the medium-temperature return heat exchange tank 22, the temperature of brine is increased, the temperature of return water is reduced, and energy conservation is realized;

3.) a low temperature (ambient temperature) storage area: the return water 27 flows into an interlayer of the specially-made pond (namely below the heat-conducting isolation membrane 32 of the brine storage pond), and the more the return water is accumulated, the more the return water is, the more the heat is, the saturated brine 31 to be used is heated for a long time by using the waste heat;

outside the technical scope of the patent, the construction of subsequent treatment sites and auxiliary facilities, such as a lithium salt dehydration area, a packaging and transportation out of a storage area, a mixed salt treatment and accumulation area and a goods transportation area, must be considered in the design according to the process flow as shown in fig. 6; combining with scientific planning and design of the terrain, refer to fig. 4 and 5.

The target salt lake water is evaporated and concentrated in a floating salt sunning pond in a salt lake until lithium carbonate is saturated, and then is excessively evaporated and concentrated by more than 5% (ensuring that the lithium carbonate crystallized and separated has enough quantity to support reverse dissolution in the coldest season, and the lithium carbonate is saturated at the lowest temperature to increase the maximum value of [ Li + ] in the brine) as shown in figure 1.

At the later stage of the coldest season, the reverse dissolution of lithium salt is completed, the clear brine is a lithium salt saturated solution at the lowest temperature, the Li < + > is the highest, the content of miscellaneous salt is the lowest, the solid-liquid separation of the brine is carried out, the clean saturated brine is stored in a brine storage tank 31 consisting of a special double-layer isolation film (the upper isolation film is a heat-conducting film, and the later backflow water enters the heat-conducting film to exchange heat with the brine), and as shown in the figure 4 and the figure 5, the miscellaneous salt is collected and stored in a centralized way according to the situation.

A high-temperature lithium extraction area is built, and the high-temperature lithium extraction area is divided into an upper part and a lower part:

the lower part is a high-temperature backwater heat exchange pool 2, namely a large pool is installed and constructed on the terrace, and the full underground type/full aboveground type/half aboveground type installation and construction can be adopted; the terrace foundation needs to be treated firmly, waterproof and free of water accumulation, leakage water needs to be automatically and timely discharged, and facilities are reasonable and powerful;

the assembly type high-temperature backwater heat exchange pool is built by two methods, wherein the first method is a component assembly type, namely, the backwater pool is divided into a plurality of component units according to the process intention, the component units are formed by welding, bonding, processing, assembling and forming materials such as steel, plastic and the like, and then the component units are transported to a construction site to be assembled integrally, common steel is carefully subjected to corrosion prevention, then a high-elasticity chemical fiber protective layer 1 layer is laid, then a waterproof plastic film 3 channel is laid, high-elasticity chemical fiber sponge cloth is laid under the steel for protection, the rubber plate is laid on the top for abrasion prevention and scratch prevention, and a.

The frame rod template is built, namely a combined floating heat exchange pool is built and welded on a qualified ground by using profile steel, frame rods and templates, and the inside and the outside of the pool body need to be well antiseptic, heat-insulating and heat-preserving;

the high-temperature return pond is huge in size, a foundation cannot sink when the high-temperature return pond is erected and located on a high-grade terrace, the terrace is specially required to be paved with three layers of anti-seepage plastic films before concrete pouring outside the normal building installation construction standard requirement, a layer of high-elasticity protective film is arranged above and below the plastic films, a small-pipe-diameter PE plastic pipe for suction detection transversely penetrates below the upper layer of plastic film, a pipe head is thrown out of the terrace and hung at a high level, water backflow is prevented, and the pipe head is protected from light and aging;

thus, the leakage water can be prevented from continuously seeping downwards, and the foundation is ensured to be safe and sound.

The assembly type water return pool is preferably directly arranged on the ground, so that the construction is convenient and the investment is saved;

the assembly type water return pool can also be located on a ground beam (or a steel girder), and the floor conditions (such as deformation and the like, for remediation and loss reduction) can be obviously checked through a semi-passing inspection channel;

the outer surface layer of the wall plate of the water return pool needs anti-aging treatment, a high-strength long-life plastic template is adopted in the wall plate, and then a heat insulation layer and an anti-seepage layer are arranged.

The front part of the high-temperature water return tank 2 is provided with a miscellaneous salt deposition tank 9, and the concrete arrangement of the miscellaneous salt deposition tank is determined according to the length condition of the water return tank body and the crystallization condition of miscellaneous salt (the middle part is appropriately provided with the miscellaneous salt deposition tank);

a return water distribution tank 8 is arranged at the rear part of the high-temperature return water tank 2 (a miscellaneous salt flushing pipe header pipe 20 is arranged in the tank); then, a partition beam is built, and foundation screws are welded on the partition beam in advance (a fixed bearing partition seat 3 is installed in the future);

the last part of the high-temperature water return tank 2 is a lithium salt deposition funnel tank (groove), and the lithium salt deposition funnel tank is contracted downwards to collect lithium salts and other deposits, as shown in figure 7.

The upper part of the high-temperature lithium extraction area is a temperature-rising lithium extraction pool 1 floating on the high-temperature return water pool 2, and the temperature-rising lithium extraction pool is divided into a front part, a rear part and a middle part which are respectively explained in detail:

1.) the front part of the heat exchanger is a parallel U-shaped heat exchange groove assembly consisting of a plurality of groups of parallel U-shaped straight through grooves, the heat exchanger floats in a high-temperature water return pool 2, the cross section of the heat exchanger is shown as a graph A-A, the U-shaped straight through grooves are formed by bending corrosion-resistant thin steel coil plates, the U-shaped straight through grooves are assembled and connected as a graph B-B, and the U-shaped straight through grooves are called as parallel U-shaped heat exchange groove groups after being connected to form enough heat exchange surfaces; brine is arranged at the upper part of the heat exchange surface, the temperature is lower, return water is arranged below the heat exchange surface, the high temperature is higher, and automatic heat exchange is realized;

2.) the rear part is provided with a deposition funnel pool which is funnel-shaped, extends downwards and contracts into a small pool groove, so that solid matters can sink and gather conveniently, and the deposition funnel pool is made of corrosion-resistant medium-thickness steel plates (welding and assembling); a (extraction type or scraper type) lithium outlet system 7 of a conveyor (which belongs to conventional equipment, is not shown in detail in the drawing, and is only shown by an installation central line) is arranged at the bottom of the tank and used for conveying deposited lithium salts and the like to a specified dehydration station;

the small lithium-extracting system is not provided with a conveyor, and can be directly extracted by inserting a suction pipe into the bottom of the tank (like a septic tank for extracting sewage).

3.) a special bearing and isolating seat 3 made of medium-thickness corrosion-resistant steel is used in the middle, as shown in fig. 9, the bearing and isolating seat is fixed on a foundation bolt of a cross beam of the pool body, and the front part and the rear part are connected and communicated after the bearing and the front part are opened;

each U-shaped straight-through groove is provided with a lithium salt flushing pipe at the bottom in the groove in a long way, and precipitated salt is flushed downstream in a downstream manner as shown in figure 7 and A-A and finally enters a lithium salt deposition funnel pool (groove);

on the floor of the high-temperature water return pool 2, a high-temperature return water channel is formed between every two U-shaped straight-through grooves, each return water channel is provided with a miscellaneous salt flushing pipe which is shown in figure 7 and A-A in the figure and is arranged in a through way, and the precipitated miscellaneous salt is flushed downstream and finally flushed into a miscellaneous salt deposition groove 9;

the lithium salt flushing and sweeping pipe system 19 is, as shown in fig. 10, formed by connecting a main pipe with a plurality of branch pipes (the pipe heads are flat and horizontally arranged for horizontal linear injection), each branch pipe is further connected with a plurality of groups of flushing pipes (the pipe heads are flat and injected), the flushing pipes and the branch pipes are connected in a large sample as shown in fig. 10a, each group of flushing pipes are symmetrically connected, the included angle is 2 beta, and the lithium salt flushing and sweeping system beta is 20-25.

The system 20 for flushing and sweeping the miscellaneous salt is shown in figure 10, a main pipe is connected with a plurality of branch pipes (the pipe heads are flat and are in horizontal linear injection), each branch pipe is further connected with a plurality of groups of flushing pipes (the pipe heads are flat and are beneficial to injection), the flushing pipes and the branch pipes are connected in a large sample as shown in figure 10a, each group of flushing pipes are symmetrically connected, the included angle is 2 beta, and the system beta for flushing and sweeping the miscellaneous salt is 30.

A conveyor is arranged at the bottom of the miscellaneous salt settling tank to convey out the settled miscellaneous salt, (conventional equipment has the characteristics of extraction suction type or scraper bucket lifting type, and can finish the task of conveying out the settled salt only by selecting and customizing installation);

a conveyor is arranged at the bottom of the lithium salt deposition funnel pool (groove) and used for sending out deposited salt, and a suction type can be selected (conventional equipment, multiple types and only required for type selection installation);

the material receiving port of the conveyor is mostly provided with water leakage, a water collecting pit is arranged at a proper position of a floor below the material receiving port of the conveyor and needs to be prevented from leakage, and the water collecting pit is provided with an automatic/manual drainage system to drain water in time so as not to influence the sinking of a foundation.

A shrinkage deposition funnel pool (groove) at the rear part of the temperature-rising lithium extraction pool is installed in place: the corresponding part of the supporting pit seat at the rear part must be trimmed firstly, as shown in figure 7, the joint surface needs to be smooth, the joint degree is high, no obvious local confrontation exists, then a 3mm soft rubber plate, three layers of impermeable plastic diaphragms, a 2mm soft rubber plate are paved, the lower seat sedimentation tank is in place, a bolt is nailed up after proper adjustment, the peripheral joint is irrigated with glue, the sealing is complete and waterproof, the joint grouting glue is made of high-elasticity temperature-resistant (90 ℃) ageing-resistant resin, and the joint grouting glue and the civil engineering tank are combined into a whole after the joint grouting, and no gap leakage exists.

A medium-temperature heat exchange zone: the heat exchange device consists of a medium-temperature reflux heat exchange pool 22 and a heat exchange halogen supply water pipe 21, and is explained in detail as follows:

1.) the medium temperature reflux heat exchange tank 22 is reliably connected and assembled by a large-sized formed double-layer hollow drainage pipe (all round or semicircular section, U-shaped, trapezoidal section and semi-elliptical section are selected), and becomes a section of large-section pipe duct (generally: closed pipes, open channels and open channels, hereinafter collectively referred to as pipe tanks) as shown in fig. 4 and 5, the medium temperature reflux heat exchange tank is arranged in a straight line, and the tank body is made of: graphite PE plastic is added (or more aging-resistant is selected), the specification is super large or a special shape can be specially customized, and the field assembly connection is usually as follows: welding and gluing are reliable, and a screw clamping plate is arranged at the lap joint part;

2.) the heat exchange halogen supply pipe 21 passes through the interior of the medium-temperature reflux heat exchange tank 22 along the length direction, and the flow directions are opposite, as shown in fig. 4 and 5, heat exchange is carried out, and energy is saved; in order to improve the efficiency, the brine supply pipeline has large area and multi-shape disturbed running water, and modes such as special-shaped pipes, multi-group pipes, curves and the like can be used; the medium-temperature reflux heat exchange tank can go through an s-shaped three-return-stroke or multi-return-stroke return extension path, or adopts a compact mode such as a spiral flow channel to extend the flow channel and increase the heat exchange surface, and as shown in fig. 11, a plurality of sets of miscellaneous salt deposition discharge ports (grooves) are reasonably arranged in the heat exchange tank;

3.) if the medium-temperature reflux water tank is amplified by many times, the multi-pass compact arrangement becomes a large-scale pond type structure, deposited miscellaneous salts do not need to be removed, and the 'permanent' deposition in the pond is ready for development and utilization in the future.

In a small-scale project, the medium-temperature reflux heat exchange area adopts a pipe groove mode, namely a discontinuous open structure can be adopted, namely a section of open channel and a section of closed channel are adopted, the pipe is stable and has good heat preservation, the open channel is convenient to install and maintain, and both the open channel and the closed channel are considered; the pipe groove is internally provided with a brine supply pipe which is uniformly distributed with supports 23 to prevent brine supply pipes from blocking crystallized mixed salt from flowing downwards, and a mixed salt collecting outlet (groove) is reasonably arranged.

The medium-temperature heat exchange area can adopt a large-section long-flow channel structure in large-scale production, and the heat exchange halogen supply water pipe can adopt the following three schemes:

1.) bonding and building a U-shaped channel mode by using a heat-conducting plastic film, namely an all-plastic heat exchange surface, as shown in figure 8b, forming an all-plastic parallel U-shaped heat exchange groove group structure, wherein the reflux water pipe groove is formed by using a flat-bottom trapezoidal section, so that the construction is facilitated;

2.) the steel-plastic plate can be matched with the heat exchange surface, the corrosion-resistant thin steel plate is bent into a short U-shaped through groove tile (the height of two sides is insufficient), then the corrosion-resistant thin steel plate is connected with a heat conducting plastic sheet to be heightened, and the corrosion-resistant thin steel plate is turned over a cross bar and connected with an adjacent short U-shaped through groove tile, as shown in a figure 8a, so that an enough heat exchange surface is formed; exchanging heat under normal pressure, covering an open channel section for heat preservation, and additionally arranging a second-stage water pump to send brine to a high-temperature lithium extraction pool;

3.) the heat exchange tube with the special section has good heat conductivity, flexibility and corrosion resistance.

A low-temperature (normal-temperature) storage area is built after salt drying, is built in summer in the same year, and is used for collecting saturated brine to form a brine storage pool when the brine is coldest in winter and spring; during the production of lithium extraction in summer of the next year, the return water is collected (below the heat conducting film and above the bottom isolation film) to form a collection water return pool, and the positions of the two pools are superposed to eliminate the expansion of the two pools.

The water return tank initially has no water, return water continuously flows in during normal production and is gathered below the heat conduction diaphragm to naturally heat saturated brine in the brine storage tank, so that the double-layer hollow aerated plastic bubble film can float in a region with higher temperature of the surface of the tank for saving energy, and the double-layer hollow aerated plastic bubble film can preserve heat, prevent wind blowing, prevent evaporation and dissipate heat;

if the land and the investment are saved, the low-temperature area can be built on the lake surface, the waste heat in the return water can not be utilized in the low-temperature area, the heat exchange flow channel is specially prolonged in the medium-temperature area, and the waste heat is absorbed as much as possible; the energy consumption for lithium extraction is huge, and the energy conservation is very important.

The accessories such as pipeline, valve, water pump, other instruments are installed: a water flow adjusting structure, namely a water drain door floating ball adjusting system 12 is arranged at a return water outlet of the high-temperature return water heat exchange tank 2 to ensure that the water level is appropriate; for example, when the water level rises, the floating ball moves upwards, the lower linkage water outlet is enlarged, the drainage is increased, the water level falls back, the floating ball falls, the linkage water outlet is closed, the water outlet is reduced, the water level rises, and the steps are repeated in this way and are dynamically balanced within a set range;

manufacturing and installing a water distribution pipeline system, a lithium salt flushing and sweeping pipeline system, a mixed salt flushing and sweeping system, pipelines such as a pump, a valve and the like and other accessories in each stage; the material has good resistance to brine corrosion, strength, stability and the like at 90 ℃, the heat conductor has good heat conductivity, and common steel can be coated with plastic for corrosion prevention.

In normal operation, the water flow process path is as follows:

the saturated brine in the brine storage tank is sucked into a brine supply pump 25, as shown in fig. 4 and 5, is pressurized and then is conveyed through a brine heat exchange supply pipe 21, passes through a medium-temperature zone heat exchange tank 22, reaches a brine supply distribution pipe 14 of a high-temperature zone lithium extraction tank through a water supply pipe 13, is divided and then flows into each U-shaped channel of the lithium extraction tank through a distribution branch pipe 15, is heated by electric power (resistance heating 16+ microwave heating 18) and bottom high-temperature return water, is heated, crystallized, precipitated and washed in the lithium extraction tank, passes through an inner lithium salt washing bed 4 at the last part to flow out (the temperature of the water is highest at the moment and the lithium extraction task is finished), starts to flow back, and after lithium is washed by an outer lithium washing bed 5 (a large amount of mixed salt is dissolved at the moment), enters a high-temperature backwater heat exchange tank 2 through a backwater distribution tank 8, and heats the brine above the upper part below a parallel U-shaped tank group, flowing, heat exchanging, cooling and crystallizing while precipitating miscellaneous salts (flowing out of the high-temperature return water heat exchange tank 2, then entering the medium-temperature zone return heat exchange tank 22, flowing into the heat exchange brine supply pipe 21 in the medium heating tank, flowing out of the medium-temperature zone after completing the heat exchange of the section, carrying a large amount of crystallized miscellaneous salts, finally flowing into the low-temperature zone return water tank, and exchanging heat with brine in the brine storage tank at the upper part (or around) of the low-temperature zone return water tank for a long time, as shown in fig. 6, 4 and 5;

in all processes, the brine flows in a reverse direction, and high-efficiency heat exchange is carried out by large temperature difference, so that the supplied brine is heated; meanwhile, the reflux water loses heat energy and is cooled, and mixed salt is separated out, and the part which is not deposited flows to a water return tank for precipitation and recrystallization precipitation.

The crystallized and separated miscellaneous salt at the bottom of the water return pool is a chemical raw material, and is treated according to needs, temporary and long-term accumulation is comprehensively considered during site selection and construction, so that the materials are easy to deal with, the resources are precious, and the ecological environment is superior.

The energy-saving mode is adopted, heat insulation and preservation are realized during construction of all facilities, and the other external leakage surfaces have good heat preservation except normal heat exchange surfaces; floating low-cost foam plastic with good heat insulation property is required for the water surface heating area (hot water area) of each pool (lake) to preserve heat and save energy, and strong heat dissipation such as evaporation, wind-blowing convection and the like is strictly prevented; the high-temperature water surface of the lithium-extracting area needs to be provided with a double-layer or three-layer bubble-filled heat-insulating cover sheet and a cover plate which are heat-dissipation-preventing and evaporation-preventing, and the double-layer or three-layer bubble-filled heat-insulating cover sheet and the cover plate are required to be free of corrosion, light in weight, good in heat insulation and easy to implement, and are provided with a linear track transverse pull cover (or a turnover cover plate type, a.

Lithium extraction is a very energy consuming matter, a Tibet salt lake is seriously lack of other energy sources, sunlight is abundant, and the enhancement of high-efficiency solar energy utilization is particularly important, (monocrystalline silicon with the highest photovoltaic power generation efficiency can reach 23%, and the existing use is generally 10% -15%);

1.) direct heating: collecting sunlight from all directions by using reflectors, irradiating the sunlight to the water surface of the lithium extraction pool, and heating brine; or the lower part of the irradiation light-receiving heating body is inserted with brine for heat transfer; for example, the upper part of the device is efficiently heated by light received by a copper plate (light receiving heating element) partially inserted into brine, and the lower part of the device is cooled in water;

2.) indirect heating: collecting sunlight from all directions by using a reflector to irradiate the sunlight to a low-pressure (close to normal pressure) water evaporator, and introducing steam to a lithium extraction pool by using a heat insulation pipe to heat brine;

and (3) exploring and researching a good material: high light receiving, high reflection, high heat conductivity, and a better method, can realize heating brine by using a large amount of sunlight;

in the future, a synchronous light-gathering film (like a synchronous satellite) can be spread in space, and the strong light is received to benefit mankind.

The technology is advanced, clean photovoltaic, wind energy and water energy are utilized, and heat pipe heat exchange energy conservation/screw heat pump heat energy/geothermal energy extraction can be explored.

And (4) safety aspects: personnel safety, electricity safety, microwave safety, machine operation safety, chemical poisoning, burn and the like, and also is prepared with first-aid medicines which are required to be understood carefully;

a production field; when pulling the warning, a road sign is arranged, and an isolation railing is arranged; electric heating, microwave heating, safe power utilization, microwave measures and automatic control measures are required; in summary, safety is a central priority! Safety protection work must be done to ensure smooth production.

Drawings

Name of each figure:

FIG. 1 solubility of lithium carbonate in Water

FIG. 2 solubility of miscellaneous salts

FIG. 3 solubility of salts

FIG. 4 is a schematic view of the elevation difference distribution

FIG. 5 is a schematic plan view of the arrangement

FIG. 6 is a process flow diagram

FIG. 7 shows a high-temperature lithium extraction zone system, section A-A, and B-B assembly (for cross arm, various types of section steel)

FIG. 8 is a schematic view of a heat exchange surface, a steel-plastic mixed heat exchange surface and b full-plastic heat exchange surface

FIG. 9 shows a receiving packer

FIG. 10 is a schematic view showing the connection between the branch pipes and the shower nozzle pipes in an enlarged rotation manner in the sweeping pipe system (the principle of lithium salt sweeping and miscellaneous salt sweeping is completely the same), and

FIG. 11 is a schematic diagram of heat exchange in the middle temperature zone, a three-pass S-shaped flow channel, b other multi-pass flow channel

Reference numbers in fig. 4 and 5 indicate that: 1 floating temperature-rising lithium extraction pool, lithium extraction liquid, 2 high-temperature backwater heat exchange pool, 3 backwater receiving and isolating seat, 4, internal washing lithium salt bed, 5, external washing lithium salt bed (groove, deep) lithium salt deposition groove, funnel, 7 lithium salt delivery system, 8 backwater distribution groove, 9 mixed salt deposition groove, 10 mixed salt delivery system, 11 water outlet pipe, 12 water outlet doors, 13 floating control system, 13 brine supply pipe, 14 brine distribution pipe, 15 distribution branch pipes, 1 branch pipe, 16 light, electric heater, 17 lithium crude salt washer, 18 microwave heating and support system, 19 lithium salt flushing system, 20 mixed salt flushing system, 21 heat exchange brine supply pipe, 22 medium-temperature backwater heat exchange pool, 23 brine supply pipe, uniformly distributed support, 24 quick-opening valves, 25 supply brine pump, 26 return pipe, 27 backwater pool, 29 deposited mixed salt in water return pool, 28 backwater pool, 29 Floating pipe of saturated brine 32 brine storage pool heat conduction isolating membrane 33 brine storage pool in bottom isolating membrane 30 crystallization lithium salt 31 brine storage pool for use

In the elevation difference distribution diagram of fig. 4, elevation positions of facilities are not actual positions, but are drawn for clarity of logical relationship expression, clarity of association relationship among process links, and simplicity of drawing; each processing link in the actual production can be determined according to the guiding thought.

In the schematic plan layout diagram of fig. 5, the positions of the facilities are not actual positions, but are drawn for clarity of expressing logical relationships, for clarity of the association relationships of the process links, and for the purpose of simplifying the drawing.

From the elevation difference distribution diagram of the elevation and the plane layout diagram of the elevation and the elevation difference distribution: saturated clean brine 31 to be used is heated by return water 27 in a brine storage pool, the temperature is slightly increased, the saturated clean brine flows through a quick-opening valve 24 through a brine supply pump 25, enters a heat exchange pipeline 21 with good heat conduction, fully exchanges heat in a medium-temperature return heat exchange pool 22, then enters a brine supply pipe 13, flows into a brine supply distribution pipe 14, flows into a U-shaped straight-through groove through a distribution branch pipe 15, namely floats in a temperature-increasing lithium extraction pool 1, and the temperature is obviously increased along with heat exchange; and continuously flowing, heating by a photoresistance heater 16 (multiple groups), crystallizing and separating lithium, dissolving impurity salt in the crude salt fed by a lithium crude salt feeder 17 (or multiple groups), feeding the crude salt into a final deposition tank, heating again by microwave irradiation of a microwave heater 18 until the temperature reaches the highest temperature, heating all the way, crystallizing and separating lithium till the point, then upwards passing through an inner salt washing bed 4, flowing through an outer salt washing bed 5, dissolving a large amount of impurity salt, feeding the brine into a high-temperature return water heat exchange tank through a return water distribution tank 8, namely, being arranged below a U-shaped straight-through heat exchange tank group, heating the brine at the upper part in flowing, reducing the temperature, crystallizing and separating out impurity salt to deposit in a impurity salt deposition tank 9, finally flowing out of a high-temperature area return water tank, feeding into a medium-temperature heat exchange area, flowing into a return water tank after heat exchange, and finishing a complete temperature-increasing and lithium.

In the high-temperature lithium extraction area system in fig. 7, in order to avoid the confusion of the drawing, the water return heat exchange pool 2: the horizontal rods (flat rods) and the vertical rods (upright columns) for supporting the U-shaped heat exchange grooves are not drawn, and are partially and schematically drawn in an A-A diagram (all dense horizontal and vertical straight strips are well understood and free from drawing), and the horizontal and vertical rods are made of: various regular and special-shaped steel materials with circular, oval, polygonal, I-shaped, T-shaped, angle steel, channel steel and the like cross sections are selected, the material is preferably corrosion-resistant steel, and if common steel materials are used, plastic is coated for corrosion prevention, as shown in figure 8;

the upright columns can be slightly deviated from left to right, and avoid and bypass the impurity salt sweeping pipes arranged in the middle, or the impurity salt sweeping pipes are deviated and avoid the upright columns arranged in the middle; the column cannot block the punch pipe injection of the miscellaneous salt flushing system, and the column is intentionally avoided in the design, as shown in fig. 7A-a; in fig. 7B _ B, J is the position of the seam of the U-shaped groove, two seams are symmetrically arranged, and the seam is not arranged at the bottommost part.

The high-temperature area water return heat exchange pool 2 can be built into a full underground type, a full overground type and a semi-underground type during building, and actually a large pool is built, the shape is the same, and only the ground exposure height is different, so that the high-temperature area water return heat exchange pool is not respectively drawn, and the high-temperature area water return heat exchange pool is comprehensively considered to be a semi-underground type superior point.

In fig. 4 and 5, the medium temperature zone reflux heat exchange tank 22 has a straight-through type simple structure, and only the drawing is simple, so that the principle is well understood; the heat exchange halogen supply water pipe 21 in the medium temperature heat exchange pool 22 is only drawn with two pipes for showing the design intention which is easy to understand; in actual production, the medium-temperature zone reflux heat exchange pool needs to be arranged into an s-shaped three-return stroke, more return stroke type or spiral flow channel type, as shown in fig. 11, the flow channel is increased, the heat exchange area is increased, the heat exchange time is prolonged, the heat exchange quantity is increased, and meanwhile, the structure is compact, the construction is easy, the energy conservation is facilitated, the management is convenient, and the cost is low.

The heat exchange halogen supply water pipe 21 needs to be provided with a plurality of pipes in parallel, the heat exchange area needs to be increased, the intention of disturbing water flow is also included, parameters such as shape, size and number are determined in the design, and the contradiction between the heat exchange capacity increase and the cost reduction is balanced; the position, the number and the specification parameters of the brine supply pump are designed according to the processing capacity, the pipe diameter and the number are designed, and the trend and the separation and combination of pipelines are designed, so that the energy is saved, and the details such as water flow resistance and the like are reduced.

The mixed salt delivery system 10 can be arranged on the left side or the right side; the lithium salt discharging system 7 may be provided on the left side, right side, rear side, and is reasonably determined by integrating the site conditions in the design, one of which is illustrated in fig. 4 and 5.

The technical requirements and technical descriptions of all the figures are summarized:

1.) feeding brine pumps (more than 2 work, 1 standby is suitable), only 2 schematic pictures are drawn in the figure;

2.) photoelectric heater 16, which refers to a certain number of light heaters and electric heaters (which can be installed singly) in some way;

3.) the arrangement of the crude lithium salt washing tank is determined on site according to actual requirements.

4.) all pipeline lines are good in heat conductivity and heat insulation (efficient and reliable heat preservation measures are needed) without participating in heat exchange;

5.) installing rapid valves (necessary electromotion) according to requirements on all pipeline lines, installing corresponding inspection instruments and facilities at each monitoring point, and ensuring safe and smooth production by automatic linkage of the inspection instruments and facilities needing linkage; various accessories and detection facilities used in the production field need to be fully matched, and the pictures and texts can not be expressed one by one.

6.) the power of the production plant is unstable (or clean self-generating electricity is used), and the electrical facilities need reliable countermeasures and protective measures;

7.) building efficient lighting facilities on the salt-solarizing pond, collecting solar energy in the mountains and all over the fields and wind energy which has been showwed everywhere, and heating and extracting lithium;

8.) naturally evaporating crystals in the halogen storage pool, wherein pure lithium carbonate is used in the initial stage, then the pure lithium carbonate is accompanied by miscellaneous salts, and full salts (all components are saturated and separated) are crystallized and separated out if the time is long, and the reasonable treatment is required.

Detailed Description

Performing scientific and fine design on the detailed investigation and comprehensive planning of the target salt lake and the surrounding landforms; according to the designed designated position, a floating salt pond and supporting facilities are quickly built up, clean salt lake water is poured, the salt lake water is naturally evaporated and concentrated to reach the saturation of [ Li + ] (the annual evaporation capacity of the Tibet north plateau is 2300mm, and the annual rainfall is 180 mm);

then excessive evaporation and concentration are carried out for more than 5 percent, the quantity of the lithium carbonate crystallized and separated out in the period is ensured to have enough quantity to support reverse dissolution in the coldest season, and the maximum value of [ Li + ] in the brine is increased;

after the reverse dissolution of the Li < + > is completed in the later stage of the coldest season, the solid-liquid separation is carried out on the brine in the salt sunning pool, and the obtained clear brine is a lithium salt saturated solution at the lowest temperature, has the highest Li < + > and the lowest content of miscellaneous salt and is stored in a special double-layer membrane brine storage pool which is planned, designed and built for standby application as shown in a figure 4 and a figure 5, and the solid is miscellaneous salt (chemical raw material).

Constructing a lithium extraction field: the temperature rise lithium extraction is technically divided into three large blocks, namely a high-temperature area, a medium-temperature area and a low-temperature area, the construction is fully started after the salt sunning is started, the temperature in the salt lake area is low, the construction is early in winter, only June to September can be performed, and the civil engineering work must be completed in the current year;

the low-temperature area, namely the normal-temperature area, is simple in civil engineering work, a large pit is built in a low-lying area by using a bulldozer and a loader, the water volume in the solar salt pond (and the water volume for capacity expansion in the future) can be sufficiently accommodated, the ground surface of the pit is an original soil layer, and the pit is roughly repaired, leveled, polished and compacted, so that local sudden high and low shapes cannot appear, and the isolating membrane at the bottom layer of the water storage pond is prevented from being scratched and unevenly stressed in the future; the pond is built in the same year, and is put into use in winter in the same year to store brine;

the brine storage pool is formed by paving a double-layer plastic isolation film into a pit pool which is subjected to civil engineering treatment, the upper isolation film is a heat conduction film, brine for use is filled on the heat conduction film, warm storage backflow water is collected during production below the brine storage pool, heat energy is transmitted into the brine through a diaphragm to be utilized, and the bottom isolation film prevents the backflow water from leaking; each layer of isolation film is required to be independent, intact and crack-free, and the seam is tight and leak-free (the condition that mutual connection can not happen absolutely during splicing and gluing);

in actual production, the isolating membrane can be externally connected and expanded while water is poured (the viscose is completely cured within 30 minutes);

the high-temperature lithium extraction region is divided into two parts: the lower part is a high-temperature backwater heat exchange pool 2, and the upper part is a floating temperature-rising lithium extraction pool 1, which are respectively explained in detail.

The high-temperature backwater heat exchange pool 2 is assembled and built into a huge pool, as shown in fig. 7, the front part of the pool is provided with a pool tank for depositing the miscellaneous salt, namely a miscellaneous salt deposition tank 9 (a plurality of tanks can be arranged in sections according to the requirement); a backwater distribution groove 8 is arranged in the middle, a partition beam is arranged behind the backwater distribution groove, and foundation bolts are welded on the partition beam in advance (the partition beam is fixedly connected with a sealing seat 3); the final part is a descending pit base (to be post-fitted with a lithium salt deposition funnel 6) that shrinks downward;

high-temperature water return heat exchange pool 2: the construction area is large, the working temperature is high, the annual temperature difference of the foundation is large, the foundation sinking caused by leakage is a damaged source when the load is uniform and the bearing is not large (the depth of a water pool is temporarily considered to be 3 m), and the terrace is elaborately constructed according to the civil engineering requirement (the size, the depth, the firmness, the durability, the heat preservation, the leakage prevention and the leakage water are collected and extracted in time by an automatic system, and no water is accumulated on the ground surface …) because the terrace is used for a long time; the foundation construction also requires the following special requirements besides the conventional civil engineering anti-leakage requirement:

1.) specially-made seepage-proofing and monitoring, seepage-proofing collecting and discharging system, namely three layers of seepage-proofing plastic chemical fiber films are laid before concrete pouring, and redundant layout is needed (the middle layer needs to be in a dense wrinkle shape or a convex-concave embossing shape, so that large deformation allowance is ensured to correspondingly extend and correspond when the foundation sinks and deforms a small amount in the future, and the foundation is intact and leak-proof in small deformation); the plastic chemical fiber film is completely paved on the ground or is guided to a lower drainage position from a certain underground position, so that the leakage water is far away from the foundation;

2.) a plurality of plastic tubules transversely penetrate through the middle layer anti-leakage plastic chemical fiber film, small holes are reserved at specific positions on the tubules, the ends of the tubules are thrown out of the ground, suction is performed from the ends in future, the leakage condition is detected, and water seepage is extracted; ordinarily, the exposed pipe head is hung high, inverted and prevented from water backflow, and the pipe head needs anti-aging measures;

therefore, leakage exists, the leakage water is timely removed, the foundation cannot be damaged, and the backwater heat exchange tank is not influenced.

Reassembled and built good water return heat exchange pool

A miscellaneous salt deposition tank is built at the front part of the high-temperature return water heat exchange tank, a pumping (or scraper type, chain plate type, bucket type lifting type and the like) complete set of conveyor system 10 is arranged at the bottom of the deposition tank, as shown in figure 7, more water is used when miscellaneous salt is delivered by adopting a pumping mode, and separated liquid is introduced into the isothermal position of the medium-temperature heat exchange tank according to the high and low temperature and continuously participates in heat exchange; the separated solid miscellaneous salt is used as other chemical raw materials, and waste heat recovery can be considered;

the bottom plate of the high-temperature return water heat exchange pool 2 is sequentially provided with:

1.) the front part is provided with a mixed salt sedimentation tank 9, the middle part can be additionally provided with a mixed salt sedimentation tank, and the specific quantity and position are determined according to the length condition of the tank body and the crystallization condition of the mixed salt;

2.) the back part of the high-temperature water return pool 2 is provided with a return water distribution groove 8 (the groove is internally provided with a miscellaneous salt flushing pipe 20);

3.) then arranging a transverse partition beam in a rear mounting mode, wherein foundation screws (for mounting and fixing the bearing and isolating seat 3 in future) are preset on the partition beam;

4.) the last part of the high-temperature water return tank 2 is a lithium salt deposition funnel pit seat which is contracted downwards to collect lithium salt and other deposits, as shown in figure 7.

The floating temperature-rising lithium extraction pool is an assembly structure and is divided into a front part, a rear part and a middle part for detailed explanation:

the front part of the floating temperature-rising lithium extraction pool is a parallel U-shaped heat exchange tank group, the floating temperature-rising lithium extraction pool floats in a high-temperature water return pool 2 and is a parallel U-shaped straight channel formed by connecting a plurality of U-shaped straight through tanks, for example, as shown in figure 7, A-A is a cross section diagram, and B-B is a U-shaped straight through tank connection assembly big sample, so that a large number of heat exchange surfaces are formed, and the parallel U-shaped heat exchange tank group is called; j shows in the diagram B-B that the width of the used thin steel coil plate is insufficient and the splicing is carried out to generate the joint position, when the U-shaped groove is high and deep, the number of the joints is increased, the joints are not required to be arranged at the lowest position, and the concrete manufacturing is as follows:

the U-shaped groove is formed by bending the corrosion-resistant steel thin coiled sheet coiled material: usually, the width of the rolled plate B1 is 800mm, the width of the rolled plate B2 is 1100mm, the width of the single plate is insufficient, and the rolled plate must be spliced, and the width of the spliced wide band B is: b1+ B2, B1+ B2+ B1, B2+ B1+ B2, 3B1, 3B 2.; so that the seam is not at the lowest level; when two rolls of thin roll plates are spliced, the roll plates are unfolded, a long joint is spliced into a joint B which is B1+ B2 along the longitudinal direction, then the joint is bent into a U-shaped straight through groove, the length is determined according to the design (the length of the roll plate is specially ordered in a steel mill according to integral multiple of the length of the U groove), the joint is not required to be at the lowest position of the U-shaped groove, the U-shaped groove is hung on a support which is already arranged, and is locked by a special recyclable quick expansion screw, as shown in a figure 7B-B, so that a parallel U-shaped heat exchange groove group is formed;

(splice bar width B, not calculating the amount of folding, allowance is taken into account when the thin steel coil plate is sized)

The rear part of the floating temperature-rising lithium extraction pool is provided with a funnel-shaped sedimentation pool (groove) which is contracted downwards into a small sedimentation pool (groove), so that solid matters can be conveniently sunk and gathered and can be easily collected and conveyed out; manufacturing (welding and assembling) a corrosion-resistant medium-thickness steel plate;

when a deposition funnel pool at the rear part of a lithium extraction pool is installed in place, a base at the last corresponding part of a water return pool, namely a descending pit pool at the last part, is required to be smooth, a layer of 3mm rubber plate is laid after no obvious countermeasure is provided/the pond is cleaned again, a layer of three layers of impermeable plastic membranes are laid again/a layer of 3mm rubber plate is laid again, the rubber plate joint seam is glued after plastic films are not damaged, the whole body is impermeable, a shrinkage and subsidence lithium extraction funnel pool is seated, the funnel pool is connected with a special bearing sealing plate 3 after being checked to be qualified, and finally, high-elasticity high-temperature (90 ℃) resistant aging resin glue is used for pouring seams (the funnel pool is combined with the pool base into a;

lithium salt deposit conveyor 7 installation:

1.) the rear part of the lithium extraction tank is a main heating temperature rise region, the temperature rises rapidly, and a large amount of lithium salt is crystallized and separated out;

2.) the fine-washed lithium ore precipitation of the part is also carried out;

3.) crystallizing and separating lithium salt and finely washing lithium ore by increasing the temperature in the front parallel U-shaped heat exchange groove group;

the forward flow is collected and sinks together, so that the collection is convenient; thus, this section is shaped like a narrowing funnel, narrowing down to the bottom lithium salt deposition cell (trough) where the extraction (or other form) conveyor exit lithium system is located, as shown in fig. 7 for conveyor 7,

the conveyor 7 is used for conveying the deposited lithium salt to a specified dehydration station, performing solid-liquid separation at a professional dehydration station, introducing the separated low-temperature liquid into a heating lithium extraction tank, and continuously separating lithium; introducing the separated high-temperature liquid into a water return tank to participate in heat exchange; the separated solid salt is the target product, namely high-purity lithium concentrate, and is packaged and transported out.

The middle of the floating temperature-rising lithium extraction pool is a special bearing and sealing seat 3 made of medium-thickness corrosion-resistant steel, as shown in figure 9, the front part and the rear part are organically connected and communicated after the front part is started, and the bearing and sealing seat is fixed on a transverse partition beam foundation bolt of the high-temperature return pool 2.

Lithium salt flushing and sweeping pipes are arranged at the bottom in each U-shaped straight-through groove in a long way, as shown in figure 10, a plurality of pipes are connected to form a flushing and sweeping system 19, a water pump is used for pressurizing and jetting high-speed water flow, sediment is flushed and swept smoothly and flows downwards, and finally the sediment enters a lithium salt deposition funnel pool (groove) and is conveyed to a dehydration station by a conveyor.

A medium-temperature heat exchange zone: consists of a medium-temperature reflux heat exchange pool 22 and a heat exchange and halogen supply pipe 21 which is arranged upstream.

The medium-temperature reflux heat exchange pool 22 is used for excavating a corresponding pit pool according to design requirements, making a foundation, performing normal foundation treatment according to the standard requirements of civil engineering, paving three layers of anti-seepage plastic films before concrete pouring of a terrace, wherein the upper part and the lower part of each plastic film are respectively provided with a high-elasticity protective layer, and a small-pipe-diameter PE plastic pipe for suction detection is transversely penetrated under the uppermost plastic film (the specific position of the pipe is provided with a small hole), so that the protective layer, the plastic layers and the pipe head are required to be intact in the whole construction process, the small pipe head is thrown out of the terrace, is thrown out of the upper opening edge of the heat exchange pool, is hung in a water-; the plastic film and the protective layer are locally led to a safe drainage position (drainage is easy to see) below about 200mm underground, fine sand concrete is poured for protection during pouring, then the terrace is finished, and the plastic layer is properly corrected through proper vibration;

the surface layer of the heat exchange pool is reliably assembled by a formed double-layer hollow drain pipe (the cross section is all round or semicircular, U-shaped, trapezoidal, all elliptical or semi-elliptical. the round cross section can be made of PE + graphite carbon powder), the joint seam is coated with thick glue, a splint is required to be worn for abutting joint, and the joint seam is coated with glue and is closed completely;

the hollow structure has good heat preservation, high construction speed, installation gradient i of 0.01-0.02 downstream and easy cleaning of mixed salt sediments; the bottom of the tail end is connected with a large-caliber water discharge (return) pipe 26 which is connected to a return water return pool 27 as shown in figures 4 and 5, and the heat exchange pipe groove is in a straight shape in the figures, so that the drawing is simple and the design principle is convenient to understand;

when the medium-temperature heat exchange zone is actually used, the medium-temperature heat exchange zone is preferably designed into an s-shaped three-return or even more return or other forms, as shown in fig. 11, (a spiral flow channel type can also be adopted), so that the heat exchange flow is increased, the external heat loss is reduced, and the high efficiency and the energy saving are achieved; the heat exchange area is reasonably provided with a miscellaneous salt sedimentation tank (groove) and a discharge and conveyor;

the heat exchange in the medium-temperature area is low in cost, high in efficiency and strong in economy, and the heat exchange is fully utilized as much as possible; (the heat exchange cost of the high-temperature area is too high, the heat exchange brine volume of the low-temperature area is large, the temperature is not increased much, the brine exchanges heat with the nature in a large area for a long time, and finally, the brine is dissipated in a large quantity, and the effect is low).

The medium temperature heat exchange area can use a large-section long-flow channel structure in large-scale production, and at the moment, the brine supply pipe can adopt a U-shaped channel mode formed by bonding and building heat-conducting plastic films as shown in figure 8b to form an all-plastic fiber type parallel U-shaped heat exchange tank group structure; in the flat-bottom backwater heat exchange tube tank, the U-shaped channel is equal in height; in the circular bottom and inclined bottom backwater pipe grooves, the U-shaped channels are not equal in height.

The middle temperature heat exchange area and the low temperature heat exchange area have low working temperature, and the U-shaped heat exchange groove can also be used

1.) steel and plastic mixed heat exchange surface: a roll of corrosion-resistant thin steel plate coiled material is unfolded and then bent to form a shape (such as a round or oval part, a U-shaped or trapezoid small short arc tile), and because of insufficient height, two adjacent small arc tiles are compensated and connected by a heat-conducting plastic sheet to form a steel-plastic mixed U-shaped heat exchange groove set, which is called a steel-plastic U-shaped heat exchange groove set for short, as shown in fig. 8 a;

2.) full plastic heat exchange surface: plastic sheets are lapped on the cross bars, and the drooping amount is adjusted to form a continuous U-shaped heat exchange tank group, as shown in figure 8 b; the plastic has low cost, corrosion resistance and convenient construction, can increase the heat exchange area with high cost and improve the heat exchange quantity; the corrosion-resistant steel heat exchange surface has high strength, high temperature resistance and high manufacturing cost, the total consumption is reduced, and the combination of steel and plastic is reasonable, so that the capital is saved.

If the medium-temperature heat exchange area adopts a larger pond type structure, deposited miscellaneous salts do not need to be removed, and the deposited miscellaneous salts are permanently deposited in a pond and wait for development and utilization in the future.

The heat exchange pool of the medium temperature heat exchange area can be fully opened, namely an open channel, and the heat exchange pool is easy to inspect and maintain, but has serious heat dissipation and poor safety; if a totally-enclosed pipe is used, the pipe cannot be penetrated and the maintenance cannot be carried out; after compromise, one section of opening and one section of closing are adopted, namely, the opening type is interrupted, and the section length is designed and determined, so that the structural stability is strong, and the difficulties of heat preservation, energy conservation, pipe penetration, cleaning and maintenance are taken care of; all open channels in the area need to be covered with heat insulation boards, heat insulation is reliable, and obvious protective safety marks, safety guardrails and the like are required to be arranged;

a plurality of brine supply pipes are arranged in the medium-temperature heat exchange tank 22, the pipeline material has good heat conductivity and is resistant to saline-alkali corrosion, and a positioning support frame 23 (like a plastic sheet shaped like a Chinese character 'mi', the circulation area is not occupied, and the brine pipes are separated and limited) is used for fixing the position to prevent the brine pipes from mixing; the pipeline trend can not become a standard straight line, s waves are required to be formed or local small spiral arrangement is adopted (two adjacent sections must use a forward spiral and a reverse spiral, the front section is twisted, the rear section is corrected, otherwise the spiral shape is formed, and is unfavorable for flushing and sweeping the miscellaneous salt), so that the heat exchange is facilitated for disturbing the flowing water, the pipeline cannot be arranged in a certain range of the lowest part of the cross section in the heat exchange tank, and the miscellaneous salt can flow conveniently.

Improve heat transfer ability, compromise with overall economy overall planning, contradict to unify, high heat transfer requires the pipeline more thin heat transfer performance higher and higher, requires that the pipeline is little surface area big, but the cost is high, and flow resistance is big, erects economic nature variation such as the degree of difficulty is big, so will technological economy overall planning trade-off, sets up in reasonable area.

A low-temperature (normal-temperature) collecting and storing area, which is built in summer and autumn in the last year and is the part built firstly in the lithium extraction link, the saturated brine is subjected to solid-liquid separation in the lowest temperature period in winter and spring, clean brine is stored in a brine storage tank for standby application, and when the temperature is normally raised in summer for lithium extraction production, the normal-temperature brine is pumped away and flows to warm backwater, and the warm backwater enters the lower part of a heat exchange isolation membrane to form a backwater tank which is separated from the brine storage tank by a membrane, is overlapped/connected in position and naturally exchanges heat to eliminate the expansion; the bottom layer film of the water return tank needs to be checked to be perfect before receiving the return water, the bottommost isolation film extends outwards when the bottom layer film is insufficient in size, and when the original length is insufficient, the bottom layer film is externally widened by special adhesive bonding, so that the return water and the deposited miscellaneous salt are reliably guaranteed to be stored.

The water return pool is originally anhydrous, warm return water flows in when the temperature is normally raised for lithium extraction, water is accumulated to form a pool, saturated brine in the brine storage pool is naturally heated, and the double-layer hollow aerated foam plastic film is used for preserving heat, preventing wind blowing and preventing evaporation and heat dissipation for energy conservation in a region with higher pool surface temperature;

in order to fully save energy again, the water return pool and the water inlet pipe section of the water pump can be extended into a convection channel for heat exchange, the heat energy obtained by heat exchange is immediately sent away and converted into effective utilization energy, otherwise, a large amount of heat energy cannot be utilized after heat exchange in the pond and is naturally dissipated;

the low temperature area can be built on the lake surface, so that the land and the investment are saved, the waste heat in the return water can not be utilized, and the heat exchange flow channel is specially prolonged in the medium temperature area to absorb the waste heat to the utmost extent.

The method is characterized in that the crystallized and separated miscellaneous salt at the bottom of the water return pool and the miscellaneous salt flushed down from other pools are chemical raw materials, and if the miscellaneous salt is not required to be accumulated in the pool for a long time and wait for development, the factors are fully considered during site selection and construction of the pool, so that the factors are reasonably coped with, the resources are precious, the ecology is superior, the development and the utilization are considered, and the approval is required.

Lithium extraction is a very energy-consuming matter, the science and technology is endless, clean photovoltaic, wind power and water power are utilized, meanwhile, heat pipe heat exchange energy conservation/screw heat pump squeezing heat energy/geothermal energy are also explored, and particularly, brine is explored through light condensing irradiation for directly heating brine to raise the temperature, and brine is explored through indirect heat transfer after light condensing irradiation for heating other objects to raise the temperature.

The Tibet salt lake is seriously lack of energy resources and mineral resources, the sunlight is abundant, and the high-efficiency utilization of solar energy is particularly important to be enhanced (the monocrystalline silicon with the highest photovoltaic power generation conversion efficiency can reach 23 percent, the existing use is generally 10 to 15 percent, and the visible utilization rate is low);

1.) direct heating: collecting sunlight from all directions by using reflectors, irradiating the sunlight to the water surface of the lithium extraction pool, and heating brine; (ii) a Or the lower part of the irradiation light-receiving heating body is inserted with brine for heat transfer; for example, the upper part of the glass plate is irradiated to a copper plate (light receiving and heating body) partially inserted into brine, the upper part of the glass plate is efficiently subjected to light receiving and heating, and the lower part of the glass plate is cooled in water; the light condensing technology is adopted, the light guide fiber is convenient to transmit, and the light can be widely utilized;

2.) indirect heating: collecting sunlight from all directions by using a reflector to irradiate the sunlight to a low-pressure (close to normal pressure) water evaporator, and introducing steam to a lithium extraction pool by using a heat insulation pipe to heat brine; the brine is indirectly heated by using a light gathering technology and optical fibers for convenient transmission;

the light receiver (receiver) has rough surface and strong light absorption, can be surface treated by a single material, and can also be made of a composite material; the temperature rises after the light is received (irradiated), a light-transmitting heat-insulating casing (heat-insulating housing) is arranged for preventing heat dissipation, heat energy is continuously conducted downwards, the lower part of the heat-insulating casing is inserted into brine to heat the brine, the heat conductivity of the material is strong, the surface of the underwater part is treated to prevent corrosion, and the corrosion-resistant heat-conducting material can be sprayed and plated; therefore, special good materials for research are developed: the method has high sunlight receiving, reflection and conductivity, and a better method can realize heating the brine by using a large amount of sunlight;

in the future, a synchronous light-gathering film (like a synchronous satellite) is spread in the outer space, and is gathered at seaside and desert unmanned areas, and the gathered strong light is received to benefit mankind.

Installation of facilities, pipeline, valve and water pump

1.) installing optical direct and indirect heating devices, installing electric heating facilities and installing microwave heating facilities;

2.) manufacturing and installing accessory facilities such as water distribution pipes, lithium flushing pipes, miscellaneous salt flushing pipes, water collecting and draining in each stage

3.) installation of all detection instruments and meters such as pipelines, valves, water pumps and the like

4.) the heat exchanger also has better heat conductivity, and the heat insulating material has good heat insulating property;

the energy-saving mode is adopted, heat insulation and preservation are realized during construction of all facilities, and the other external leakage surfaces have good heat preservation except normal heat exchange surfaces; the lake surface heating area (hot water area) should float low-cost foam plastic with good heat insulation for heat preservation and energy conservation, and prevent heat dissipation such as evaporation.

And (4) safety aspects: the lithium extracting pool in the high-temperature area is a high-temperature area, the temperature of the microwave heating section is highest and is close to a boiling point, and all water surfaces are provided with a double-layer or three-layer bubble-filled heat-insulating cover sheet and a cover plate which are heat-dissipation-preventing and evaporation-preventing during production, are not rusted, have light weight and good heat insulation, and are transversely covered by a wire track (or a turnover cover plate cover sheet); pulling a warning, arranging a road sign and an isolation railing; electric heating, microwave heating, safe power utilization, microwave measures and automatic control safe production measures are required; in summary, safety is a central priority! Safety protection work must be done to ensure smooth production.

The corrosion resistance refers to the corrosion resistance of the material to the whole process flow of the treated brine within 86 ℃.

Claims (9)

1. Lithium resources (lithium carbonate and lithium hydroxide) are core materials for manufacturing high-energy-density new energy lithium batteries, the Qinghai and Tibet account for more than 80% of lithium resources in China and are limited by conditions, the Tibet relies on solar salt to extract lithium, the Tibet is usually a civil engineering solar salt pond, the manufacturing cost is high, the occupied area is huge, the ecological environment is damaged, the damage is serious in use, the repair is difficult, the operation cost is high, the collected energy in use is far less than …, and the capacity of the battery is always in the vicinity of 10-15% of the original plan and cannot be discharged for many; the modern society develops at a high speed, photovoltaic power generation, wind power generation and clean hydropower develop faster in Tibet, bloom all the time, and the solar salt drying and lithium extraction are possible and are about to enter practical application. In order to assist the people in getting out of the dilemma of lithium extraction from the sun salt of Tibet in China and arouse salt lakes which are deep and asleep for generations to donate precious lithium energy, the complete large-scale sun salt lithium extraction process and technical equipment patent technology are specially provided, and the floating type sun salt, photoelectric heating and continuous countercurrent floating heat exchange are adopted to extract lithium concentrate (process and equipment), and the method is characterized in that:

the assembly type high-temperature water return heat exchange pool is adopted, and two ways are adopted for completing the heat exchange:

firstly, combining a steel structure: processing and prefabricating steel into a plurality of steel structure components, and transporting the components to a site to assemble a high-temperature return water heat exchange pool;

secondly, the construction formula is as follows: standard parts such as profile steel, a hack lever, a proper template … and the like and specific construction materials are used for constructing a high-temperature backwater heat exchange pool on site;

after the high-temperature backwater heat exchange tank body is built, corrosion prevention, heat preservation and leakage prevention are carried out, and 3 layers of special protection, leakage detection and leakage prevention diaphragms are particularly emphasized.

The assembled high-temperature backwater heat exchange pool can be completely built on the ground and also can be built in a moderate deep pit pool, and the ground is exposed in a low way in the arrangement mode in the pit, so that the heat is well preserved.

2. The front part of the floating temperature-rising lithium extraction pool is a parallel U-shaped straight-through groove heat exchange groove group (called U-shaped heat exchange groove group for short),

bending corrosion-resistant stainless steel thin coil plates into U-shaped straight through grooves, assembling a plurality of groups side by side according to design requirements, and isolating heat exchange of upper and lower water bodies; the rear part of the sedimentation funnel pool is formed by welding and assembling medium-thickness corrosion-resistant steel;

the middle part is provided with a bearing and isolating seat which is fixed on a foundation frame at the bottom of the water return heat exchange tank by a foundation bolt, and the front part and the rear part are organically connected.

3. In the large-area low-cost medium-temperature heat exchange pool, a low-cost large-area full-plastic heat exchange surface is arranged, so that heat exchange is sufficient, the cost is low, energy is saved, and a steel-plastic mixed heat exchange surface can be used;

the medium-temperature reflux heat exchange pool can be built, low-cost open containers (prefabricated parts are assembled on site) such as rubber and plastic, chemical fiber and glass fiber reinforced plastic can be embedded into a pit, and the direct-buried heat exchange pool is good in construction, good in heat preservation and low in manufacturing cost.

4. The large-scale water-holding permanent building with high Tibet temperature difference (86 ℃ at most and 40 ℃ at least), low-cost anti-leakage facilities and foundation are specially treated.

5. Saturated brine in the brine storage tank is heated by the return water for a long time, and heat exchange is performed again to save energy.

6. Heat exchange technology and heating mode: the patent combines a light and thin high-thermal-conductivity plastic sheet and a corrosion-resistant thin steel sheet, uses an open normal-pressure container, and has small consumption of corrosion-resistant steel; the heat exchange capability and the efficiency are improved, the plastic heat conducting fins (quantity) with low cost and easy installation are increased,

the heating mode is as follows: the surface heat transfer of the resistance heater, the sunlight irradiation heating, the microwave three-dimensional heating, the high-temperature backwater conduction heating, the large-area conduction heating of the middle-temperature zone backwater heat exchange pool and the small-amount heat transfer of the low-temperature zone are combined, and particularly, a special microwave heating system (additionally patented technology) is adopted.

7. The heat exchange process flow adopts continuous countercurrent heat exchange, namely: exchanging heat in a high-temperature area of a lithium extraction workshop; exchanging heat in a middle temperature area of the return pipe groove; long-term heat exchange is carried out in a low-temperature area in the brine storage tank; the heat exchange layout of the medium temperature zone can adopt an s-shaped three-return stroke and more return strokes or a spiral flow passage type, thereby increasing the heat exchange surface, prolonging the heat exchange time, increasing the heat exchange quantity and the like.

8. The energy-saving mode and the new technology are utilized, except for normal heat exchange surfaces, all facilities are insulated and heat-preserved during construction, and other outer leakage surfaces are well insulated and are always intact; all the exposed water surface and lake surface heating areas (hot water areas) need to float several layers of foam plastics with low cost, good heat insulation and easy laying, thereby preventing heat dissipation such as evaporation and the like, and adopting high-level heat preservation and energy conservation;

the technology is endless, clean photovoltaic power generation (highest efficiency is 21%), wind power and hydropower are utilized, meanwhile, solar energy is explored efficiently, brine is heated directly by spotlight irradiation and heated by indirect heat transfer of other devices by spotlight irradiation; the heat pipe heat exchange energy conservation and the screw heat pump extraction heat energy recycling are also explored.

9. And (3) brine link: evaporating and concentrating the target salt lake water by adopting a floating type salt sunning pond until lithium carbonate is saturated, and then excessively evaporating and concentrating by more than about 5% (ensuring that the lithium carbonate precipitated by crystallization has enough quantity to support reverse dissolution in the coldest season, and the lithium carbonate is saturated at the lowest temperature to increase the value of [ Li + ] in the brine to the highest value); in the later stage of the coldest season, the reverse dissolution of lithium salt is completed, the content of [ Li + ] is the highest, the content of miscellaneous salt is the lowest, the solid-liquid separation of brine is carried out, and the clean saturated brine is stored in a special double-layer membrane storage pool, namely a brine storage pool for standby.

Images