224 results about "Salt mine" patented technology

The invention relates to a construction method for a gas storage reservoir in a rock salt cavity, belongs to the salt mine mining and the rock salt cavity utilization fields, and mainly used for the dissolution construction of an underground gas storage reservoir in a eutectic salt deposit. The construction method is characterized in that a method for down-flow type gas storage reservoir construction comprises the following steps: fresh water is infused into a salt deposit by a water injection pump and through a water injection pipe, the rock salt is dissolved from up to down, and at the same time, the natural gas is infused; the expenses for oil consumption of the original oil cushion method and the cost for brine purification treatment can be saved by using the method; and the method is more economical and more environment-friendly. The gas storage reservoir can be used from the beginning of construction; the single well oil cushion method with three to five years of construction cycle is not required for constructing the gas storage reservoir; the construction of the gas storage reservoir needs no cycle basically; the reservoir storage capacity is small in the beginning period; the gas storage reservoir can be used as a large gas storage reservoir in the middle and the late periods; the problems of long period for the construction of the gas storage reservoir by using the oil cushion method, difficult detection of the oil water interface, as well as other relative technical problems are thoroughly solved; and the construction method is an ideal method for rapid dissolution construction of the gas storage reservoir in the rock salt deposit.

The invention discloses a resource recycling method of waste ammonium alkali liquid for well injection and brine extraction of a sodium sulfate type salt mine, which comprises the following steps: injecting waste ammonium alkali liquid under the salt mine instead of fresh water directly or after being added with fresh water, dissolving rock salt to from mine brine, and extracting the mine brine after natural sedimentation. In the invention, the waste ammonium alkali liquid is used for the sodium sulfate type salt mine, the waste ammonium alkali liquid is injected under the salt mine for brine extraction directly or after being added with water to obtain high-quality brine with low sodium sulfate content, thereby not only the sodium sulfate content in the brine is reduced, but also NaCl in the waste ammonium alkali liquid is recycled, the resource recycling of the waste ammonium alkali is achieved, and the emission of wastes is reduced. The prepared brine can be used in vacuum salt manufacturing, brine alkali manufacturing, mine brine air-cured salt manufacturing and other chemical industries.

The invention relates to a salt, alkali and calcium combined cycle production technology by the use of well mineral salt. Based on the exploitation of brine from well mineral salt, the salt, alkali and calcium combined cycle production technology by the use of well mineral salt is a cycle production technology, which focuses on the technology for making alkali from brine by the ammonia-soda process and takes account of the vacuum salt-making (including the brine refinement) and calcium-making technologies. Alkali-making wastewater replaces most fresh water to be injected into a salt mine well to collect brine, and the obtained high-calcium brine is taken as the raw material of the salt and calcium (including liquid calcium) co-production as well as the raw material for preparing alkali and other chemical production raw materials, wherein the liquid calcium can be used to produce liquid salt; alkali-making waste residues are injected into an underground dissolution cavern, namely a salt cavern which is formed by the exploitation of brine from well mineral salt, thus accomplishing the combined cycle production technology in which alkali-making and salt-making technologies are closely related with materials. The produced wastes are used as resources or undergo a harmless treatment, thus protecting the environment. In addition, the utilization rate of sodium chloride in rock salt reaches 100%, achieving maximum efficiency.

The invention discloses a method for mining and machining a water-soluble potassium salt mine. The method disclosed by the invention comprises the following steps: firstly, exploiting the potassium salt mine by adopting a well drilling water soluble method; evaporating and crystallizing the exploited brine to sequentially precipitate a sodium salt and a potassium salt; refrigerating and crystallizing the residual feed liquid to further precipitate potassium chloride; and respectively filtering and drying the precipitated sodium salt and potassium salt to obtain finished sodium salt and potassium salt, wherein a part of mother liquor after the sodium salt and potassium salt are precipitated is used for preparing magnesium chloride, and the other part is used for preparing magnesium oxide. The method disclosed by the invention is particularly suitable for the exploitation of a potassium mine having the defects of complicated geological and hydrologic conditions, over-shallow or over-deep burial, poor quality and high carnallite content, can reduce ground collapse, improves the exploitation rate, can prepare a potassium fertilizer in a large scale and has the advantages of low energy consumption and little pollution and waste discharge.

The invention provides a drilling water soluble salt mine mining subsidence InSAR prediction method, which comprises the following steps: inverting the surface time sequence settlement of a salt minearea by using a time sequence InSAR technology, and obtaining a radar line-of-sight direction time sequence deformation quantity; extracting reliable deformation sample points near the drilling layoutposition; constructing a traditional static probability integral method model; calculating the settling volume of the high-coherence point in the vertical direction; utilizing unknown parameters of agenetic algorithm estimation model to construct a Weibull time function dynamic probability integral model, substituting all parameter result values obtained through calculation into the Weibull timefunction dynamic probability integral model, the settlement amount of all point positions at any time is calculated, and predicting a mining area time sequence deformation field. The defect that a traditional probability integral method model is mostly applied to a coal mine area and limited to a static sinking basin to mine subsidence prediction is overcome, the application space of the InSAR technology in mining area subsidence prediction is widened, and the ecological environment and production safety of the drilling water soluble rock salt mine are guaranteed.

The invention relates to a process for extracting potassium chloride by the coarse flotation of primary sylvine ores. The process comprises the following steps: (1) crushing: the sylvine ores are crushed to be smaller than 10mm; (2) ore grinding: coarse ore grinding is carried out on the crushed ores by a rod mill; (3) desliming: sylvine ore pulp after ore grinding is sent into a desliming device to remove insoluble slime; (4) flotation: under normal pressure and temperature, the sylvine ore pulp after desliming is floated in saturated bittern, a slime inhibitor, a sylvine collecting agent alkyl primary amine, a foaming agent and a nonpolar oil chemical are added, and one time of rougher flotation and two to four times of fine flotation are adopted for the flotation process; (5) concentrate washing: fresh water is added into obtained flotation concentrate for washing; and (6) filtration and drying: the washed concentrate is filtered and dried to obtain the potassium chloride. The process disclosed by the invention has simple procedures, is small in energy consumption, low in production cost, low in investment and high in recovery rate, and facilitates large-scale industrial production, and the KCl (potassium chloride) content of a KCl product is larger than or equal to 95%.

The invention discloses an organic liquid flow battery system for an aqueous system based on a salt cavern. The organic liquid flow battery system comprises two electrolyte reservoirs and liquid flowbattery stacks, wherein the electrolyte reservoirs are salt caverns with physical cavities formed after the salt mine is mined, electrolytes are stored in the cavities and comprise a positive active material, a negative active material and a support electrolyte, the positive active material is a 2,2,6,6-tetramethylpiperidine oxynitride compound, the negative active material is anthraquinones, thepositive active material and the negative active material are directly dissolved or dispersed in a system in which water is used as a solvent in ontological form, the support electrolyte is dissolvedin the system; and the liquid flow battery stacks are respectively connected to the two electrolyte reservoirs. The organic liquid flow battery system for an aqueous system based on a salt cavern notonly has the advantages such as low cost, high safety performance, stable charge and discharge performance and high solubility of active materials, but also can solve large-scale electrochemical energy storage and make full use of some abandoned salt cavern resources.

The invention discloses a saturated salt water drilling fluid for deep well salt mine drilling and a preparation method of the drilling fluid. The saturated salt water drilling fluid comprises the following raw materials in parts by weight: 100 parts of water, 2-4 parts of bentonite, 1-2 parts of sepiolite, 0.5-1 part of hectorite, 1-4 parts of FT-1 sulfonated bitumen powder, 0.2-1 part of an inorganic salt recrystallization inhibitor, 0.4-2 parts of a GTQ salt-resistant copolymer, 0.3-0.5 part of KHm potassium humate, 0.1-0.5 part of a water-based defoaming agent, 0.2-1 part of sodium carbonate, 0.1-0.3 part of sodium hydroxide, 2-10 parts of magnesium chloride, 7-15 parts of potassium chloride and 20-35 parts of sodium chloride. According to the saturated salt water drilling fluid, the influence on the performance of the drilling fluid caused by complicated environments of high-concentration inorganic salt, high temperature and the like in deep well salt mine construction can be eliminated and a technical guarantee is provided for rock salt stratum coring operation; and the saturated salt water drilling fluid is relatively good in rheological property, is capable of effectively preventing corrosion on a salt well wall and a rock core in core drilling, and is stable in performance at a high temperature and suitable for deep well salt mine sampling drilling.

The invention relates to a salt mine double-well solution mining method, in particular a salt mine double-well solution mining method. In the method, injection holes are formed on two sides of the bottom of an under central pipe in a vertical well; in a double well production process, part of clean water is separated and injected into the central pipe in the vertical well when the clean water is injected into a horizontal well, so that the clean water flows into a casting from the injection holes of the central pipe in the vertical well to dilute oversaturated brine in the casting in the vertical well; and the injection water flow in the central pipe of the vertical shaft is displayed and monitored by an electromagnetic flowmeter, so the concentration of the brine discharged from the vertical well can be controlled accurately. The method has the advantages that: 1, the concentration of the brine discharged from the vertical well in a double-well solution mining process can be accurately controlled; 2, the concentration of the brine discharged is prevented from being overhigh in a production process so as not to arouse crystallization and block the underground casting or a ground brine return pipe, and thus, the safe, continuous and high-efficiency production capacity of the salt wells is improved; and 3, as a large amount of high-pressure clean water is injected into the central pipe in the vertical well to wash the underground casting in the vertical well and the ground brine return pipe, the crystallization or scaling on the pipe wall can be prevented, potential accidents are eliminated, and well repair times and cost can be reduced greatly.

The invention provides a slow-release organic fertilizer for ginseng Chinese herbal medicines and a preparation method thereof. The slow-release organic fertilizer for ginseng Chinese herbal medicines is composed of lignin, kieselguhr, humic acid, calcium base silicic acid salt mine, nitrogen fertilizer, phosphorus fertilizer, potassium fertilizer, microelements and water, wherein the microelements comprise boron sulfate, magnesium sulfate heptahydrate, molybdenum sulfate, ferrous sulfate, heptahydrate and single superphosphate. The preparation method comprises dissolving and stirring the components, mixing and granulating to obtain the slow-release organic fertilizer. The slow-release organic fertilizer for ginseng Chinese herbal medicines is reasonable in components; the utilization ratio of the organic fertilizer and the productivity of the ginseng Chinese herbal medicines are greatly increased through the synergistic effects of each component; at the same time, problems of eutrophication symptoms and nutrient deficiency symptoms of crops are effectively solved; the quality of the ginseng Chinese herbal medicines is greatly improved; at the same time, water pollution problems caused by fertilizer loss are effectively prevented; soil is improved, resources are saved, and costs are reduced. The preparation method is simple and suitable for the requirements of large-scale industrial production.

The invention relates to a salt cavern building method based on opposite-well mining type old wells and an application thereof, and belongs to the technical field of salt mining. The salt cavern building method comprises the following steps that (1) detection and checking are conducted on the opposite-well mining type old wells; (2) a well is drilled between the two old wells and extends to a rock salt layer; (3) pipes are downwards put, specifically, a casing pipe and a center pipe are downwards put into the drilled well, and the center pipe is sleeved with the casing pipe; (4) oil is injected between the casing pipe and the center pipe; (5) fresh water is injected from the center pipe and reaches the old wells on the two sides through old well horizontal sections to dissolve rock salt into bittern, and the bittern is discharged from the old wells on the two sides; and (6) when a cavern reaches the set volume, injection of the fresh water is stopped, and building is finished. The salt cavern building method based on the opposite-well mining type old wells achieves the comprehensive targets of horizontal section plug removal, salt mining and oil and gas storage and is suitable for being widely applied and popularized.

The invention discloses a method for preparing potassium sulfate. The method comprises the following steps: 1) mixing and stirring potassium mixed salt mine, potassium chloride, sodium sulfate and a solvent to obtain a solid-liquid mixture; 2) regulating the solid-liquid volume ratio of the solid-liquid mixture to 1:(3-5), adding a flotation medicament for flotation, and then filtering and separating obtained flotation foam to obtain soft leonite and first mother liquor; 3) mixing the obtained soft leonite and potassium chloride according to the mass ratio of (1.6-2.0): (0.8-1.2), adding a washing solution to basically clean Na<+> in the mixture, and then filtering and separating to obtain a solid phase and second mother liquor; and 4) adding the solid phase in the step 3) into fresh water according to the solid-water mass ratio of (1.0-1.5):1, converting for 1-1.5h at the temperature of 60-70 DEG C, and then cooling, filtering and separating to obtain a potassium sulfate product and third mother liquor. According to the method disclosed by the invention, a byproduct of a salt lake, namely sodium sulfate is fully utilized, fresh water resources are saved in the production process, the production period is shortened, the production efficiency is improved and the production cost is further reduced.

The invention discloses a method for preparing potassium sulfate from brine with a low sulfur-potassium ratio. The method includes steps of (1), evaporating the raw brine to obtain potassium-mixed salt mine; (2), sun-curing carnallite; (3), feeding the carnallite to a potassium chloride workshop, and carrying out crushing, decomposing, flotation and dehalogenation on the carnallite to obtain potassium chloride concentrate; (4), feeding the potassium-mixed salt mine to a picromerite workshop, crushing the potassium-mixed salt mine, mixing the potassium-mixed salt mine and tailings with one another in water after the tailings obtained at the step (3) are subjected to dehalogenation, and carrying out grinding, transformation, flotation, separation and washing to obtain picromerite concentrate; (5), mixing the picromerite concentrate and the potassium chloride concentrate with each other in water to obtain mixtures and transforming the mixtures to obtain potassium sulfate products. The method has the advantages that technical routes of existing processes for producing potassium sulfate from salt lakes are improved, accordingly, shortcomings of methods for producing the potassium sulfur from brine with a low sulfur-potassium ratio in the prior art can be overcome, and the reasonable and feasible method which includes simple processes and short procedures and is low in cost and free of pollution can be provided for producing the potassium sulfate from the brine with the low sulfur-potassium ratio from salt lakes.

A method of sealing a passage in a body with a sealing composition comprising (a) a major proportion of a latex emulsion or colloid; and (b) a minor proportion of lauric acid or a laurate compound; and (c) at least one further selected additive, ideally a latex coagulation inhibitor, wherein said composition is pumped into said passage where it is set or coagulated to form a seal. Advantageously, the laurate compound is ammonium laurate and coagulation is conveniently induced by adjusting pH of the sealing composition from alkaline to acidic pH range. The method is particularly well suited to sealing in faulty formations or sealing sites and may be used in sealing within salt mines which contain brines.

The invention discloses a salt mine old cavity full mining-induced space gas-injection bittern-discharging method. The salt mine old cavity full mining-induced space gas-injection bittern-dischargingmethod comprises the steps that a new cavity is built first and then communicates with an old cavity, gas is injected into the old cavity to enable bittern in the old cavity to be discharged from thenew cavity, then a gas storage is formed, and sediment gaps are basically occupied by the gas finally, so that gas injection for bittern discharging in sediments is achieved. The technical problem that in the prior art, the bittern in the sediment gaps cannot be discharged is solved, the old cavity forming rate is increased, and the gas storage volume of the old cavity is increased to enable the built gas storage to store the more gas; and the overall form of the old cavity does not need to be measured, and the problem that in the prior art, form detection of the butted-well old cavity is difficult is solved. According to the salt mine old cavity full mining-induced space gas-injection bittern-discharging method, the output-to-input ratio is high, and the building speed is high.

The invention discloses a double-well construction method of a large gas storage in a high-impurity salt mine. The double-well construction method comprises the steps that a vertical well and a deviated well are excavated; the vertical well and the deviated well communicate; pipe cutting is conducted on the deviated well to form a salt cavern with the vertical well end being lower than the deviated well end; and gas is injected to the deviated well, so that bittern in the salt cavern is discharged out from the ground surface through the vertical well to complete construction of the gas storage. According to the double-well construction method, restriction of objective geological conditions is broken through, and the technical problem that in the prior art, a large salt cavern gas storage cannot be constructed in a high-impurity salt mine is solved.

The invention discloses a process for extracting KCl coarse grains by carrying out flotation on solid sylvinite primary ores, comprising the following steps; (1) crushing the solid sylvinite primary ores; (2) carrying out coarse grinding on the crushed sylvinite; (3) feeding the sylvinite material subject to coarse grinding into a flotation machine for primary rougher flotation and secondary refined flotation; and (4) filtering and drying concentrates obtained by the secondary refined flotation, thus obtaining the high-quality KCl bulky grain product. The product is purely white and transparent; the average grain size is 1mm-2mm; and the KCl grade is not less than 90% (by weight), thus exceeding the common industrial and agricultural high-class KCl product standards of class-II and class-III and reaching the special industrial KCl standard of national standard GB6549-1996I.

The invention provides a method for utilizing potassic solid ore to separate and extract potash magnesium sulphate fertilizer. The method comprises the following steps: potassic sulphate ore and magnesium chloride saturated brine which are obtained through solarizing and evaporating a brine saltern in a potassic sulphate type saline are used as raw materials; potassium in the potassic sulphate ore is salted out and leached through the magnesium chloride saturated brine to obtain a saturated potassium solution; the saturated potassium solution is added with the brine saltern and is evaporated to prepare low-sodium magnesium sulfate and carnallite mixed ore; and the low-sodium magnesium sulfate and the carnallite mixed ore are decomposed and transformed to obtain the potash magnesium sulphate fertilizer. The potash magnesium sulphate fertilizer prepared through the method meets the national GB / T20937-2002 standard for a qualified product; and the yield of potassium is more than or equal to 60 percent. The method is suitable for processing the potassic sulphate type saline brine or the chloride type brine saltern ore with low yield of carnallite prepared through the addition of halogen, as the concentration of the potassic saturated brine potassium obtained through evaporating the brine saltern of the potassic sulphate type saline can not be ensured by the influence of rainfall amount, and magnesium chloride is unsaturated or has unhigh concentration due to that ,the magnesium chloride saturated brine is influenced by the factor of rainfall .

The invention discloses a multistage drive ore dissolution method used for mining salt mines, which is characterized in that: water injected into an ore deposit stepwise infiltrates to dissolve the mines through a multistage water supply ditch consisting of a primary water supply ditch and secondary water supply ditches, wherein the extension directions of the water supply ditches are vertical tothe ground water flowing direction; the interval of the water supply ditches is 100-700m, preferably 200-600m; besides, stirring boats are arranged in the secondary water supply ditches to uniformly mix a solvent of water and mineral brine of the previous stage dissolved mines, which flows out of the stratum, so as to form a new solvent. Through the method, the water level is integrally raised, and the total amount of beneficial mineral resources mined from dissolvable mines is increased; the flow velocity of the solvent is reduced, the contact time with solid minerals is prolonged, and the dissolution rate is improved; and a dominant channel is cut off, and the direct-emission waste of the solvent is effectively reduced. The method is applied to exploitation of shallow, scattered, low-grade and soluble solid minerals through water dissolution.

The present invention is one method of preparing potassium sulfate with sulfate type lake bittern resource. The preparation process includes the following steps: shining bittern to obtain mixed sulfate mineral with sodium chloride, schoenite, magnesium sulfate and potassium chloride as main components and mixed potassium salt mineral with sodium chloride, potassium chloride, magnesium sulfate and carnallite as main components; mixing these two kinds of mineral and converting with water at normal temperature to obtain coarse mixed schoenite mineral; floating the mixed schoenite mineral to obtain concentrated mixed schoenite mineral; adding water to the high-grade concentrated mixed schoenite mineral and decomposing directly to obtain potassium sulfate product; water washing the tailing to obtain industrial salt. The technological process is power saving and low in cost, and has other advantages.

A thermally dissolving method for selectively mining useful potassium chloride and part of magnesium chloride from potassium salt mine by use of shaft, 4 pipes and liquid bed layer includes such steps as arranging the halogen mining pipe, dissolving liquid pipe and heating pipe in shaft, filling anti-emulsifying agent to form a liquid bed layer in salt stratum, and filling the dissolving liquid while filling steam to dissolve the useful ore. Its apparatus is also disclosed.

The present invention discloses a method for quickly extracting lithium carbonate from saline lake water and a system for the same. The method comprises: first quick-freezing the saline lake water to obtain lithium-rich brine, then evaporating under reduced pressure to enable lithium carbonate to be rapidly precipitated out. The method has advantages of short process flow and less labor consumption, thereby enabling continuous automatic operation, high energy utilization and environment-friendly. Further, the crystallization rate is several times faster than that of the salt-pan process and the grade of lithium carbonate salt mine obtained can reach 95% or more, therefore the method of the present invention is particularly suitable for industrial production in the remote saline lake region. The system comprises a reduced-pressure evaporation crystallizer, a vacuum-pumping apparatus, a brine preheating apparatus and a brine cooling apparatus, which concentrates the brine by quick-evaporation of the water, promotes lithium carbonate to form non-uniform nucleus, and improves the crystallization efficiency.

The invention provides a slow-release organic fertilizer for tobaccos and a preparation method thereof. The slow-release organic fertilizer for tobaccos is composed of lignin, kieselguhr, humic acid, calcium base silicic acid salt mine, nitrogen fertilizer, phosphorus fertilizer, potassium fertilizer, microelements and water, wherein the microelements comprise boric sulfuric acid, magnesium sulfate heptahydrate, molybdenum sulfate, ferrous sulfate, heptahydrate and single superphosphate. The preparation method of the fertilizer comprises dissolving and stirring the components, mixing and granulating to obtain the slow-release organic fertilizer. The slow-release organic fertilizer for tobaccos is reasonable in components; the utilization ratio of the organic fertilizer and the productivity of tobaccos are greatly increased through the synergistic effects of each component; at the same time, problems of eutrophication symptoms and nutrient deficiency symptoms of crops are effectively solved; tastes of tobaccos are greatly improved; at the same time, water pollution problems caused by fertilizer loss are effectively prevented; soil is improved, resources are saved, and costs are reduced. The preparation method is simple and suitable for the requirements of large-scale industrial production.

The invention relates to a method for enriching lithium in carbonate type salt lake brine, which comprises the following steps of: alternately performing low-temperature evaporation and freezing placing treatment on the salt lake brine; and after each evaporation or placing treatment, performing solid-liquid separation to remove solid-phase salt mine to obtain Li<+>-enriched liquid-phase brine. According to the method provided by the invention, lithium ions are enriched in the liquid-phase brine by a variable-temperature evaporation method; the method can make use of natural energy and has the advantages of environmental friendliness and low energy consumption; and the concentration of the enriched lithium ions can exceed 30g / L.

The invention relates to a method for preparing potassium chloride from solid kali salt mine through rotating decomposition and positive flotation, belonging to the technical field of chemical industries, in particular to a process method for producing potassium chloride by mining the solid kali salt mine in an underground manner. The process flow disclosed by the invention comprises the steps of coarsely crushing the solid kali salt blocky mine raw material in a closed manner, rotatably decomposing and selectively grading, mineralizing a pipe flow, carrying out columnar positive flotation, separating, washing slurry, separating again, drying and obtaining a potassium chloride product. The method disclosed by the invention has the outstanding benefits that: the method for preparing the potassium chloride from the solid kali salt mine through the rotating decomposition and positive flotation is provided at first time; the potassium chloride product is produced by aiming at the solid kali salt blocky mine raw material mined in an underground manner; and the process has wide popularization value.

The invention provides a preparation method of magnesium hydrate, and relates to the technical field of magnesium hydrate. The preparation method comprises the following steps of: preparing a raw material magnesium salt solution by magnesium chloride or magnesium sulfate separated out of salt mine or sea salt, adding a mixed aqueous alkali precipitator prepared by the ammonia water, the alkali metal hydroxide or the alkaline-earth metal hydroxide to generate precipitate of magnesium hydrate, filtering, washing, thermally modifying water, aging in a cooling way, filtering, washing and drying to obtain a magnesium hydrate product of which the grain size is 0.5-5.0mu m and the purity is larger than 97%, and treating and recovering the filter liquor in the process to obtain ammonia water, preparing the mixed aqueous alkali to be recycled by the recycled ammonia water, the alkali metal hydroxide or the alkaline-earth metal hydroxide according to the proportion by the mass percent such as (4-9): 1, so that the mixed bases can be recycled, therefore, various defects of the existing chemical precipitation method can be overcome, and the high-purity and low-granularity magnesium hydrate product can be prepared at low production cost.

The invention provides an improved method for producing low-salt high-quality soda ash dense by taking light soda ash produced by a hot method integrated soda process as a raw material. The low-salt high-quality soda ash dense can be prepared by the following steps of: in the process of producing the light soda ash by using the hot method integrated soda process, controlling the mass fraction of NaCl to be lower than 0.015 percent by adding a washing intermediate product of sodium bicarbonate filter cake so as to enable the mass fraction of light soda ash NaCl to be lower than 0.3 percent; and then producing the low-salt high-quality soda ash dense by taking the low-salt soda ash dense as the raw material and adopting a solid-phase hydration method or extrusion method. The method overcomes the defects that waste liquid of the low-salt soda ash dense produced by an ammonia-soda process has large discharge amount and the low-salt soda ash dense cannot be produced by a united soda production method; the raw material can be crude sea salt and rock salt or can be bittern explored by salt mine solution; in addition, the invention has no water liquid discharge, high quality of product and broad development prospect.

The invention discloses a tobacco cultivation method for reducing the harmfulness of cigarettes, and belongs to the technical field of crop cultivation. The method comprises the following steps: applying a cake fertilizer and a potash magnesium sulphate fertilizer in the cultivation process, namely during soil preparation and ridging and after tobacco is transplanted and survives until a rosette stage, wherein the potash magnesium sulphate fertilizer is a fertilizer containing magnesium and sulfur secondary elements, which is prepared by extracting or directly removing impurities from salt lake brine or solid potassium-magnesium salt ore through a physical method only, the total using amount of the cake fertilizer is 60-90kg / hectare based on the mass of N, and the total using amount of the potash magnesium sulphate fertilizer is 150-225kg / hectare based on the mass of K2O; after a film is uncovered, applying the cake fertilizer by combining cultivation and banking; and spraying the potash magnesium sulphate fertilizer after bottom leaves are removed, and performing pest control. The tar content in the cigarettes made of tobacco produced by the method can be reduced by 16.9 percent, the cigarette harmfulness evaluation number is reduced by 21 percent, and the quality of flue-cured tobacco reaches indexes of high-quality tobacco.

The invention discloses a one-inclined multi-vertical cascaded well group salt mine mining method. A well group axis is designed according to the mine bed depth of a salt mine; a first vertical well at the end part of the axis is drilled to establish a first salt groove; an oriented horizontal well is drilled at the other end of the axis; drilling is carried in a salt layer along the axis, and the oriented horizontal well is in butt joint communication with the first vertical well; a second salt groove is established and a second vertical well is drilled so that a pair of communicated wells are formed by the first vertical well and the second vertical well; and one or more pairs of communicated wells are reconstructed until the final vertical well is established, so that a pair of circulating wells is formed by the final vertical well and the oriented horizontal well. According to the one-inclined multi-straight cascaded well group salt mine mining method, the oriented horizontal well with the large displacement is drilled and is communicated with the plurality of vertical wells to form a plurality of double-well well sets, so that the inclined section construction of a drilling well is reduced, and the respective advantages of the vertical walls and the oriented horizontal well are sufficiently developed; the problems that the oriented horizontal well occupies excessive resources and a well shaft is easy to damage are solved; and an accident that the oriented well is blocked in a salt mining process is reduced, and the safety production level and the mining efficiency of the salt well are improved.

The present invention relates to a stowing method for a goaf of potash salt ore comprising making wall slurry into barricades each have the same area as the sectional area of a tunnel and a thickness of 0.5 to 5 meters inside the underground tunnels in the goaf of potash salt ore, with the interval between adjacent barricades being 5 to 100 meters, then stowing the interval between said barricades by using the filling slurry. The stowing method of the present invention uses the wall slurry of high strength that is solidified with a gelling agent as the main bearing material, and uses the solidified filling slurry with a low strength as the main filling material, which has a good effect when compared with conventional filling materials in that, the amount of additives that are used is smaller, the solidification time is short, the stowing strength is more adjustable, and the stowing cost is lower. Moreover, it effectively utilizes the tail liquids, thereby reducing the addition of other additives, decreasing the cost, avoiding the discharge of liquid waste and relieving the environmental pressure.