31 results about "Carnallite" patented technology

The invention discloses a controlled-release potassium-magnesium fertilizer as well as a preparation method and application thereof, and relates to the technical field of controlled-release fertilizer production. Potassium magnesium crude salt recovered through salt lake carnallite flotation crystallization is used as a core raw material, high-roundness modified potassium magnesium salt composite particles are constructed through extrusion master batch forming, roller wet amplification, centrifugal polishing shaping and micropore filling and sealing, and the controlled-release potassium magnesium fertilizer is prepared through coating. The problems that potash fertilizer particles prepared through traditional extrusion granulation have many edges and corners and are not prone to film coating are solved through a multi-stage granulation process, secondary granulation is conducted through heterogeneous fine powder materials, surface micropores are filled, the surface smoothness of the particles is greatly improved, meanwhile, the influence of potassium ions on film forming is isolated, and the potassium fertilizer has the good application prospect. According to the finally prepared controlled-release potassium-magnesium fertilizer, a nutrient release curve is precisely regulated and controlled through the controlled-release film layer, double-nutrient continuous supply of crops with high potassium and high magnesium requirements is achieved, the potassium and magnesium deficiency symptoms of the crops are reduced, the crop quality is improved, and a core technical support is provided for high-value utilization of salt lake potassium ore resources and green quality improvement of the crops.

A production process for preparing potassium chloride by using underground native carnallite ore comprises the following steps: carrying out primary crushing on the underground native carnallite ore, combining a material obtained by carrying out secondary crushing on an oversize material with an undersize material, conveying the combined material to a decomposer or a crystallizer, adding a beneficiation reagent into decomposed slurry or underflow slurry of the crystallizer, and carrying out roughing, roughing concentrate K1 and roughing tailings T1 are obtained; roughing tailings T1 are conveyed to a thickener, overflow of the thickener is collected and then returns to a decomposing tank for size mixing or flotation size mixing, and underflow of the thickener is subjected to ore grinding operation; materials discharged by the mill are conveyed to middling flotation operation to obtain middling flotation concentrate K2 and flotation tailings T2, the middling flotation concentrate K2 and decomposed slurry of the decomposing tank are subjected to roughing operation together, and roughing concentrate K1 is obtained; and the roughing concentrate K1 is subjected to secondary concentration to obtain crude potassium slurry K4, the crude potassium slurry K4 is filtered to obtain a crude potassium filter cake K5, and the crude potassium filter cake K5 is washed and filtered to obtain a potassium chloride wet material product. The product is high in recovery rate and proper in particle size.

The invention discloses a low-temperature dehydration method of hydrous magnesium chloride and anhydrous magnesium chloride, comprising the following steps: contacting hydrous magnesium chloride with ammonium chloride to obtain a mixed dehydrated raw material; and heating the mixed dehydrated raw material, and keeping the temperature for a certain time after the mixed dehydrated raw material reaches a set temperature until water in the water-containing magnesium chloride is removed. The invention also provides the anhydrous magnesium chloride prepared by the method. According to the method, synthesis of carnallite is not needed, hydrogen chloride protective gas is not needed, dehydration can be achieved through independent ammonium chloride, equipment is hardly corroded, the operation environment is good, and anhydrous magnesium chloride is prepared under the mild condition.

The invention discloses a method for purifying carnallite, purified carnallite and application of the purified carnallite. The method comprises the following steps: uniformly mixing sodium-containing carnallite, old brine and water to form a mixed system, wherein the mass ratio of the sodium-containing carnallite to the old brine to the water in the mixed system is 1: (3.56-6.15): (0-0.28); heating the mixed system to completely dissolve potassium in the sodium-containing carnallite in a liquid phase to obtain a mixed solution; carrying out solid-liquid separation on the mixed solution to obtain a carnallite saturated solution; and adding water into the carnallite saturated solution to separate out crystals, thereby obtaining the purified carnallite. According to the method provided by the invention, the carnallite is dissolved by using the old brine under a high-temperature condition to obtain a carnallite saturated liquid phase, and the carnallite can be separated out by cooling and crystallizing, so that the content of sodium chloride in the carnallite can be effectively reduced.

The invention relates to the technical field of nickel-containing dangerous and solid waste recycling, and discloses a complex nickel-containing waste smelting flue gas cleaning and comprehensive utilization method which comprises the steps that smelting flue gas is fed into a dry-method deacidification tower after being subjected to waste heat recovery and shock cooling, coarse-particle calcium hydroxide is sprayed into the dry-method deacidification tower, defluorination is preferentially carried out in a first temperature interval of the dry-method deacidification tower, and defluorination is carried out in a second temperature interval of the dry-method deacidification tower; a defluorination product is collected, and fluorine-containing dust is separated and collected through electrostatic dust collection; the dedusted flue gas enters a semi-dry deacidification tower, and fine-particle calcium hydroxide is sprayed into the semi-dry deacidification tower for deep dechlorination in a lower second temperature interval of the semi-dry deacidification tower; and discharging the purified gas after denitration, washing and ionic liquid desulfurization. The defluorination product is washed and purified to prepare hydrofluoric acid, and the dechlorination slag is dissolved and subjected to a double decomposition reaction to prepare hydrochloric acid. According to the method, a temperature gradient and absorbent particle size gradient coupling process is utilized, so that directional separation and enrichment of gas-phase fluorine and chlorine pollutants are effectively realized, the problem that carnallite is difficult to utilize is solved, and full-process recycling and ultralow emission are realized.

The application provides a process and equipment for producing potassium chloride by using carnallite as raw material. The process of the application comprises the following steps: crushing, washing, grinding, crystallization and positive flotation. Through optimization of process parameters and process flow, the application realizes the industrial continuous production of potassium chloride from carnallite on a scale of million tons, and the production efficiency is high, and the quality of the potassium chloride product, such as purity, whiteness and crystal particle size, is obviously improved.

The invention discloses a nanofluid oil-displacing agent based on solid carnallite and a preparation method of the nanofluid oil-displacing agent. The method comprises the following steps: by taking oil and gas field wastewater treatment solid carnallite rich in calcium and magnesium ions as a raw material, firstly, preparing the raw material into an aqueous solution, reacting with a betaine surfactant and alkyl sulfate salt in a foam system at a specific temperature, adjusting the pH value by sodium hydroxide and sodium carbonate, standing, centrifuging and drying, thereby obtaining the calcium and magnesium ion-rich solid carnallite. The salt-resistant calcium carbonate / magnesium hydroxide composite nanoparticles are obtained; and then dispersing the nano-particles in a polyacrylic acid polymer aqueous solution, and performing ultrasonic treatment to obtain the target nano-fluid oil-displacing agent. According to the invention, industrial solid carnallite is ingeniously converted into a functional nano material, and the prepared oil-displacing agent has excellent stability and interfacial activity, and can significantly improve the crude oil recovery rate when being used for high-water-content oil reservoirs. The method not only provides a new low-cost and high-performance oil-displacing agent selection for efficient development of an oil field, but also realizes recycling and high-value utilization of the solid waste salt, and has remarkable economic and environmental benefits.

The invention discloses a preparation method of a hydraulic cementing material for synergistically recycling coal gangue and mine water concentrated carnallite. According to the method, mine water carnallite, coal gangue, kaolin, calcium oxide and water are taken as main raw materials, firstly, metakaolin with potential activity is obtained by calcining the kaolin, then the proportion of the mine water carnallite, the metakaolin, the calcium oxide and the water is optimized by adopting an orthogonal experiment method, and the hydraulic cementing material with good mechanical properties is prepared. And an optimal ratio is determined through a compressive strength test. And then coal gangue is introduced as aggregate, so that the overall structural stability and compressive property of the material are further improved. According to the method, sulfate radicals in the mine water carnallite react with calcium oxide to generate stable hydration products such as ettringite, the gelling performance is improved, resource utilization of coal gangue is achieved, and a stable curing system is formed. The method has good hydraulicity, environmental adaptability and solid waste co-processing potential, and is suitable for the fields of industrial solid waste resource utilization and green cementing material development.

The invention provides a seawater concentrated water resource regeneration treatment method based on plate nanofiltration, which comprises the following steps of: after concentrated seawater is subjected to plate nanofiltration, settling and separating the concentrated water to obtain gypsum, and extracting the gypsum to obtain mother liquor; the mother liquor after gypsum extraction is subjected to bromine extraction to obtain a bromine product and mother liquor after bromine extraction, the mother liquor after bromine extraction is adjusted to be neutral and subjected to multiple-effect evaporation to obtain condensate water and evaporation mother liquor, the former is partially fed into an external coil pipe of a reaction settler for heat exchange, and the latter is subjected to heat preservation and sedimentation to obtain high-temperature salt slurry and clarified liquor; separating high-temperature salt slurry to obtain magnesium milk and sodium chloride, processing the magnesium milk into a magnesium sulfate monohydrate product, washing the sodium chloride to obtain bitter salt, and feeding part of the bitter salt into concentrated seawater; cooling and crystallizing the clarified liquor to obtain carnallite and mother liquor after carnallite is separated out, washing the carnallite to obtain a potassium chloride product and decomposition washing mother liquor, mixing one part of the two mother liquor with the mother liquor after bromine extraction, feeding the other part of the two mother liquor, condensate water and bitter salt into a magnesium preparation mother liquor pool, and adding caustic soda to obtain a magnesium hydroxide product. According to the method, valuable components in the concentrated seawater can be subjected to resource maximization extraction.

This invention provides a static cone penetration test (CPPT) system and method for measuring the thickness of carnallite ore layers based on an unmanned surface vessel (USV) with variable buoyancy anchoring. The system includes an USV body, a penetration unit, a main control unit, a data acquisition unit, a multi-parameter formation identification unit, and a fluid counterweight anchoring unit. When the USV body is not performing detection operations, the fluid counterweight anchoring unit increases the weight of the hull. As the static cone penetration probe penetrates the formation, it collects the end resistance at the probe tip and the frictional force on the probe sidewall sleeve, transmitting these data to the multi-parameter formation identification unit. The identification unit identifies the upper and lower interfaces of the carnallite ore layer. The control unit calculates the carnallite ore thickness based on the depth difference between the static cone penetration probes at the upper and lower interfaces of the carnallite ore layer. This invention improves measurement accuracy, resolves the contradiction between miniaturization and large reaction forces, does not damage the original crystallization environment of the salt lake, and enhances the safety of unmanned operations.

This patent application refers to a global process to obtain lithium sulfate monohydrate ore with low contents of impurities associated to chlorine and magnesium; in particular, the process consists of the concentration, through grinding, flotation, leaching and filtration stages, of the lithium sulfate present in potassium Carnallite (KCl*MgCl2*6H2O) stockpiles with high contents of lithium sulfate (Li2SO4*H2O) and sodium chloride (NaCl). The greatest advantage of the invention's process is that it uses salts and brines which are not currently being processed today and which have already been extracted far potassium production.

The invention discloses a carnallite cold decomposition process water adding amount control method, a carnallite cold decomposition process water adding amount control device and electronic equipment. The method comprises the steps that in the carnallite cold decomposition process, current basic physical property parameters of overflow liquid of a cold decomposition crystallizer are collected; on the basis of the current basic physical property parameters, the current ion concentration in the overflow liquid is predicted, and the current ion concentration comprises the sodium chloride concentration, the potassium chloride concentration and the magnesium chloride concentration; according to the current ion concentration, the target water adding amount in the carnallite cold decomposition process is determined; the opening degree of a water injection valve is controlled based on the target water adding amount, water is injected into decomposition liquid, and the decomposition liquid is mixed liquid generated after carnallite reacts with water or other solutions in the carnallite cold decomposition process. The technical problem that in the prior art, the water adding amount is difficult to accurately control in the carnallite cold decomposition process, and then the potassium salt yield and the decomposition efficiency are affected is solved.

The invention discloses a method and a system for producing potassium chloride from sylvite ore. The method comprises the following steps: S1, crushing the sylvite ore into ore particles with the particle size of less than or equal to 5mm and greater than or equal to 1mm; s2, conveying the ore particles into a decomposition and crystallization unit, and performing decomposition and crystallization to obtain crystallization underflow slurry and crystallization overflow; s3, the crystallizer underflow slurry is screened and classified, screen underflow and the crystallization overflow are conveyed to a thickening unit to be subjected to thickening treatment, and thick underflow is obtained; and S4, the dense underflow is conveyed into a reverse flotation unit for reverse flotation. According to the method, explosion nucleation of carnallite is avoided in the mineral decomposition process, fine grain loss is reduced, and the growth yield of potassium chloride is increased; meanwhile, a reverse flotation process is adopted, KCl crystal particles grow for a long time in a flotation device and can continuously grow in a supersaturated solution, and the yield and the taste of products are improved.

The invention relates to a process for extracting high-purity potassium chloride (KCl) from a carnallite ore (KCl.MgCl2.6H2O) associated with halite (NaCl). The process starts with selective dissolution, prioritising KCl and MgCl2, due to the addition of water at room temperature. Two basification steps follow, involving the addition of potassium hydroxide (KOH) to the solution obtained after dissolving the ore. The first addition makes it possible to extract all of the Mg2+ ions in the form of magnesium hydroxide (Mg(OH)2), an upgraded product. The second addition of KOH seeks to convert all the NaCl into potassium chloride (KCl) and sodium hydroxide (NaOH). This second addition of KOH is carried out in excess to promote the formation of the desired products during the following two crystallisation steps. After the chemical transformations of the mineral solution, a concentration step is undertaken to vaporise the water, thereby promoting the crystallisation of the potassium chloride (KCl). A second concentration is followed by cooling in order to form the solid sodium hydroxide (NaOH). The water vapours generated in the two concentration steps are liquefied by cooling to be recycled. The three solid products resulting from the process are dried to remove moisture, thereby complying with market requirements in terms of purity. The proposed process is characterised by zero-waste management and low water consumption, with more than 90% of the water being recycled initially, as well as recycling of the KOH at the end of the process. In addition, it has low energy requirements, since the dissolution of KOH is exothermic. The KCl production of the process is high due to the regeneration of KCl during the chemical transformations, and the process is characterised by its flexibility with respect to different compositions of the starting ore.

The invention discloses an industrial miscellaneous salt total-amount treatment device and method, and belongs to the technical field of energy utilization. The device comprises a dissolving device, a filtering device, a TOC removal device, a denitrification device, a hardness removal device, a freezing device, a separation device A, an evaporation device, a separation device B, a purification device A, a purification device B and a curing device. Industrial carnallite and water are fed into the dissolving device to be dissolved, the dissolved carnallite solution is sequentially fed into the filtering device, the TOC removal device, the denitrification device and the hardness removal device to be filtered, TOC removal, denitrification and hardness ion and heavy metal ion removal are conducted, the carnallite solution obtained after pretreatment is completed is fed into the freezing device and the separation device A, and sodium sulfate is recycled; the carnallite solution after sodium sulfate recovery is fed into an evaporation device and a separation device B to recover sodium chloride, and then the collected sodium sulfate and sodium chloride are purified through a purification device A and a purification device B respectively. The carnallite solution is fed into a curing device for curing after being subjected to resource recovery, so that full-amount treatment of industrial carnallite is realized.

The application provides a method for improving utilization of a halogen replacement completion liquid. The method for improving utilization of the halogen replacement completion liquid comprises: performing first halogen replacement on E halogen and first F halogen to obtain first halogen replacement completion liquid and first carnallite; and performing second halogen replacement on the first halogen replacement completion liquid and second F halogen to obtain second halogen replacement completion liquid and second carnallite. Compared with a traditional method of directly discharging and treating the halogen replacement completion liquid as waste liquid, the first halogen replacement completion liquid obtained in a halogen replacement-cold crystallization method is subjected to second halogen replacement with fresh second F halogen, so that potassium chloride in the first halogen replacement completion liquid is separated out, the utilization of the first halogen replacement completion liquid is improved through recycling, and the potassium chloride in the first halogen replacement completion liquid is recovered, thereby reducing the loss of potassium chloride. The method can be applied to the field of potassium chloride production, and the second carnallite can be used to prepare potassium chloride, thereby reducing the loss of potassium chloride.

A method of manufacturing a fertilizer comprising biomass, consists in that the biomass comprising, in dry matter, simple and complex proteins in an amount from 8 to 30% by weight and phosphorus compounds in an amount from 1 to 3% by weight P2O5, is mixed with at least one carbonaceous raw material selected from the group comprising lignite, bark, sawdust, humus, compost, peat and straw in an amount of 5 to 20% by weight in relation to the biomass, is ground to a particle size of less than 5 mm to produce a pulp with a dry matter content from 10 to 70%, then the resulting pulp is mixed with at least one evaporite mineral selected from the group comprising polyhalite, calcite, dolomite, gypsum, anhydrite, carnallite, sylvite, barite, after which the whole is dehydrated to a dry matter content from 40 to 85%, then mixed with alkaline raw materials in an amount sufficient to control the temperature of the mixture in the range from 60 to 140ºC and obtain a moisture content of less than 30%, preferably 10 to 15%, and then the product obtained is granulated to obtain granules with sizes from 1 to 5 mm, and alkaline raw materials forming inorganic coatings are applied to the surface of the granules, after which a substance forming an outer coating is sprayed.

The application provides a method for producing potassium chloride by mixing halogen and cold crystallization. The method mixes raw material E halogen and raw material F halogen, and then adds circulating seeds to perform primary halogen mixing to obtain primary halogen mixing slurry. The primary halogen mixing slurry is sequentially concentrated and centrifuged to obtain semi-finished product mother liquor and carnallite. The carnallite is crystallized and dried to obtain potassium chloride. The semi-finished product mother liquor is concentrated and mixed with primary halogen completion liquid, raw material F halogen, fine crystal carnallite mother liquor and circulating seeds to perform secondary halogen mixing. The raw material F halogen, the raw material E halogen and the circulating seeds can be self-made by artificial method. The method can improve the yield of potassium chloride, increase the diversity of halogen water raw material sources, greatly reduce the cost, and the overall potassium chloride recovery rate of the process can reach more than 75%.

The utility model provides a pre-mineralization flotation device. The pre-mineralization flotation device comprises a feeding part and a pre-mineralization part, the pre-mineralization part comprises a shell, a plurality of first partition pieces and a plurality of second partition pieces, the first partition pieces and the second partition pieces are located in the shell, the feeding part is used for introducing materials and air into a first feeding port, each first partition piece is provided with a first through hole, each second partition piece is provided with a second through hole, and the first through holes and the second through holes are arranged in a staggered mode; the first partition pieces and the second partition pieces are alternately arranged in the mineralization channel in the extending direction of the mineralization channel, and a gap is formed between the first through hole and the second through hole; the reaction part is provided with a reaction chamber as well as a second feed port, a solid outlet and a liquid outlet which are communicated with the reaction chamber, and the first discharge port is used for introducing mixed materials and air into the second feed port; and the bubble generation assembly is used for introducing air into the reaction part so as to generate bubbles in the reaction chamber. According to the technical scheme, the problem that the flotation efficiency of carnallite is low is solved.

The invention relates to a process for producing high-quality potassium chloride by using carnallite, which comprises the following steps of: crushing and grinding solid raw materials, adding fresh water to decompose and crystallize, reducing the content of sodium chloride in the solid raw materials through primary flotation, and reducing the content of gypsum and insoluble substances in the solid raw materials through secondary flotation, performing coarse potassium dehalogenation, coarse potassium washing, fine potassium filtering and wet product drying on foam obtained by grading, and then performing grinding and triboelectric separation on the dried fine potassium powder to obtain a final high-quality potassium chloride product; performing dehalogenation on tailings obtained by two times of flotation and underflow purified by mother liquor to form solid tailings, and performing stockpiling or filling; and returning a high-sodium product obtained by triboelectric separation to crude potassium washing. The high-quality potassium chloride meeting the GB / T 37918-2019 type I potassium chloride standard is produced by taking the carnallite ore as the raw material, the influence of the fluctuation of the quality of the raw ore is small, the high-quality potassium chloride product is stably produced under the condition of guaranteeing the overall potassium yield of the process, and the method has obvious technical advantages and relatively high application and popularization values.

The invention relates to the technical field of mining of soluble sylvite in polyhalite, and particularly discloses a polyhalite leaching agent and a preparation method and application thereof.On a maleic anhydride-sodium allysulfonate copolymer molecular chain, carboxyl generated by hydrolysis of maleic anhydride is beneficial to dissolution of K < + > in polyhalite; the sulfonic acid group on the molecular chain of the copolymer provides electrostatic repulsive force, and the whole macromolecular chain provides a strong steric hindrance effect to effectively prevent gypsum from nucleation and growth and finally form thick crystals, and when the thick crystals are stacked, many gaps are left to form a loose and porous filter cake structure, so that the effect of blocking the gypsum is achieved. A porous filter cake structure allows a fresh leaching agent to continuously flow in to dissolve residual polyhalite; meanwhile, dissolved potassium ions can be easily diffused into a main body solution.

The utility model provides a system for preparing a weighting agent for well drilling from industrial carnallite, and relates to the technical field of industrial waste salt recycling, the system comprises a feeding unit, a storage unit, a multi-stage crushing unit, a vacuum drying unit and a vacuum conveying unit, the storage unit comprises a raw material buffer storage bin and a compound medicament bin; the feeding unit is used for feeding materials to the raw material temporary storage bin, and the compound agent bin is used for containing an anti-caking complexing agent; the multi-stage crushing unit at least comprises a first screw conveyor and a crusher which are arranged in sequence, one end of the first screw conveyor is arranged in the raw material temporary storage bin, and the compound medicament bin is located above the first screw conveyor; the vacuum drying unit comprises a drying machine, and the drying machine is arranged between the first spiral conveyor and the crusher; by means of the device, industrial carnallite generated by offshore drilling can be treated, and the purpose that the industrial carnallite is prepared into the weighting agent for drilling is achieved.

The process for obtaining potassium chloride (KCI) consists of a sequence of unit stages to obtain a commercial grade product, which is a KCI obtained from low grade sources. The process starts with the salts from the potassium carnallite precipitation pits and the tails from the lithium sulfate process. These then pass through a classification and grinding circuit, then a reverse flotation stage for sodium chloride removal, followed by a leaching stage and finally washing and filtering.

The invention concerns a process for extracting high-purity potassium chloride (KCl) from carnallite ore (KCl.MgCl2.6H2O) associated with halite (NaCl). It begins with a selective dissolution, prioritizing KCl and MgCl2, due to the addition of water at room temperature. Two basification steps follow, involving the addition of potassium hydroxide (KOH) to the solution obtained after the dissolution of the ore. The first addition allows the extraction of all Mg2+ ions in the form of magnesium hydroxide (Mg(OH)2), a valuable product. The second addition of KOH aims to convert all the NaCl into potassium chloride (KCl) and sodium hydroxide (NaOH). This second addition of KOH is excessive to promote the formation of the desired products during the two crystallization steps that follow. After the chemical transformations of the mineral solution, a concentration step is undertaken to vaporize the water, thus promoting the crystallization of potassium chloride (KCl). A second concentration is followed by cooling to form solid sodium hydroxide (NaOH). The water vapors generated during the two concentration steps are liquefied by cooling for recycling. The three solid products resulting from the process undergo drying to remove moisture, thus meeting market requirements in terms of purity. The proposed process is distinguished by zero waste management and low water consumption, with more than 90% of water recycled initially, as well as KOH recycling at the end of the process. In addition, it requires little energy, as KOH dissolution is exothermic. The KCl production of this process is high thanks to the regeneration of KCl during chemical transformations, and it is characterized by its flexibility in dealing with different compositions of the starting ore.

The invention discloses ammonium carnallite as well as a preparation method and device thereof, and relates to the technical field of preparation of ammonium carnallite. The preparation method of the ammonium carnallite comprises the following steps: S1, carrying out first natural evaporation on initial mixed brine to obtain first crystal feed liquid; carrying out first solid-liquid separation on the first crystallization feed liquid to obtain a first crystallization product and first brine; wherein the initial mixed brine contains magnesium chloride and ammonium chloride; s2, carrying out second natural evaporation on the first brine to obtain second crystal feed liquid; carrying out second solid-liquid separation on the second crystallization feed liquid to obtain a second crystallization product and second brine; s3, collecting a first crystallization product and a second crystallization product; and the second brine returns to the step S1 for first natural evaporation, so that the ammonium carnallite is effectively extracted and purified from the brine, and the yield and purity of the ammonium carnallite are improved.

The invention relates to a device and a method for removing sulfate radicals in ion type rare earth ore magnesium salt enrichment, which are characterized in that water is added into the magnesium salt enrichment to prepare slurry, the slurry is refined under stirring to expose mixed magnesium oxide and floats upwards under the stirring action, CO2 gas is introduced at a certain rate to carbonize magnesium oxide into magnesium carbonate / magnesium bicarbonate, and the magnesium carbonate / magnesium bicarbonate is added into the slurry to prepare the sulfate radicals in the ion type rare earth ore magnesium salt enrichment. After the reaction is finished, discharging fine slurry through an overflow port, filtering to obtain filter residues and filtrate, detecting the content of sulfate radicals in the filter residues, and if the content of sulfate radicals in the filter residues is less than 1%, terminating the operation; if the sulfate radical content of the filter residues is larger than or equal to 1%, the filter residues are repeatedly operated until the sulfate radical content of the filter residues is smaller than 1%. According to the method, new carnallite is not introduced, the phenomenon that the purity of the enriched product is reduced by the carnallite is avoided, meanwhile, magnesium oxide in the existing magnesium salt enriched product is fully utilized, and the content of rare earth in the enriched product can be further increased while sulfate radicals in the enriched product are removed.

The invention provides a process for producing potassium chloride by using carnallite. The process comprises the following steps: carrying out flotation on first carnallite ore to obtain low-sodium carnallite; the method comprises the following steps: mixing low-sodium carnallite with a solvent to obtain first brine with the specific gravity of 1.202 to 1.204; carrying out first recrystallization on the first brine to obtain second brine with the specific gravity of 1.249-1.251 and a first potassium chloride crude product; performing secondary recrystallization on the second brine to obtain third brine with the specific gravity of 1.261-1.263 and a second potassium chloride crude product; the third brine is subjected to first evaporative crystallization, and fourth brine with the specific gravity being 1.273-1.275 and sylvinite are obtained; the fourth brine is subjected to second evaporative crystallization, fifth brine with the specific gravity being 1.314-1.316 and second carnallite ore are obtained, magnesium is removed from the first potassium chloride crude product and the second potassium chloride crude product, and a potassium chloride finished product is obtained. The recovery rate of potassium chloride in the process is high.

The application provides a carnallite and a production method thereof. The production method comprises the following steps: S1, mixing E halite and F halite to obtain a carnallite slurry; S2, performing first concentration on the carnallite slurry to obtain a semi-finished carnallite slurry; S3, performing dehydration on the semi-finished carnallite slurry to obtain a crude carnallite and a semi-finished mother liquor; S4, performing second concentration on the semi-finished mother liquor to obtain a semi-finished concentrated mother liquor, and recycling the semi-finished concentrated mother liquor to continue mixing with the E halite and the F halite, and repeating the steps S1 to S3 at least once; and simultaneously, performing decomposition crystallization on the crude carnallite to obtain the carnallite. The application can promote the growth of fine-crystal carnallite in the semi-finished concentrated mother liquor, increase the particle size of the fine-crystal carnallite, thereby avoiding the problem that the fine-crystal carnallite is completely melted by fresh water due to small particle size when meeting fresh water for washing in a crystallizer, and further improving the recovery rate of the carnallite.

The invention provides a carnallite metallogenic thickness measurement device and method based on an unmanned ship. The measurement device comprises an unmanned ship platform, a drilling measurement unit, a stratum identification unit and a control scheduling unit. The unmanned ship platform is used for autonomous sailing and fixed-point keeping in a salt lake or salt pan water area; the drilling measurement unit is installed in the middle of the unmanned ship platform and used for conducting vertical drilling at a target measurement point. The stratum identification unit is used for identifying an upper interface and a lower interface of a carnallite layer based on the data acquired by the data acquisition module, and calculating to obtain the carnallite metallogenic thickness according to a drill rod pressing depth difference value corresponding to the upper interface and the lower interface; and the control scheduling unit performs path planning and task scheduling on the unmanned ship platform and controls the drilling measurement unit to perform automatic fixed-point measurement. The method realizes full-automatic and periodic measurement of the carnallite metallogenic thickness, is suitable for salt lake resource exploration and dynamic monitoring, and has a wide engineering application prospect.

The invention relates to a countercurrent gradient decomposition speed-controlled crystallization process of large-particle high-sodium carnallite ore. The countercurrent gradient decomposition speed-controlled crystallization process comprises the following steps: (1) crushing; (2) adding into a primary decomposition crystallizer; (3) adding a decomposition medium; (4) enabling overflow mother liquor to enter a thickening tank; (5) adding fresh water, and returning to the primary decomposition crystallizer; (6) adding part of the high-sodium carnallite ore, primary decomposition crystallization underflow and tailing mother liquor or other unsaturated mother liquor into a secondary decomposition crystallizer; (7) secondary decomposition crystallization overflow mother liquor returns to the primary decomposition crystallizer; (8) secondary decomposition crystallization underflow is screened; (9) conveying underflow of the 2 # thickening pool for flotation; (10) carrying out flotation to obtain crude potassium foam and flotation tailing slurry; (11) filtering the crude potassium foam, and then washing the pulp; and (12) filtering and drying to obtain a potassium chloride product. The process flow is simple, the cold decomposition crystallization effect on large-particle solid carnallite ore is better, the processing recovery rate is high, the energy consumption is low, and the potassium chloride product is good in quality and large in particle size.