154 results about "Sodium cyanide" patented technology

The invention relates to the technical field of packing scale equipment, and provides a special packing scale for powdery sodium cyanide and a control method thereof.The special packing scale comprises a feeding hopper and a vibration table which are distributed up and down, a connecting flange coaxially fixed to a discharging opening of the feeding hopper, and a receiving hopper which is coaxially connected to the connecting flange in a sleeving mode, and the outer wall of the receiving hopper is annularly provided with a driving gear and is driven by a motor on the feeding hopper; at least one concave cavity is formed in the side wall of the receiving hopper, a rod body is hinged in the concave cavity, a replaceable balancing weight is arranged at the free end of the rod body, when the receiving hopper rotates, the rod body is unfolded under the action of centrifugal force and knocks a ton bag sling, meanwhile, the vibration table acts on the bottom of a ton bag, and the vibration table and the receiving hopper cooperatively excite the standing wave effect of the ton bag. The rod body periodically knocks the sling under the action of centrifugal force, and the frequency can be adjusted through the balancing weight. When the knocking frequency is close to the inherent frequency of the ton bag, vibration of the hanging belt can be transmitted to the whole bag body, the resonance phenomenon is caused, the vibration table at the bottom is matched to excite the standing wave effect, and loosening and even distribution of materials are achieved.

The invention relates to an efficient copper removal and recycling process for copper-cyanogen complex wastewater, which comprises the following steps: (1) critical acidification-selective crystallization of the copper-cyanogen complex wastewater: directionally recombining a copper-cyanogen complex to generate insoluble CuCN crystals by accurately regulating and controlling the pH value of the wastewater; (2) rotational flow enhanced crystallization: separating CuCN crystals from overflow liquid through a hydrocyclone; (3) gradient activation of a composite vulcanizing agent for deep copper removal: enabling the fine CuCN particles and the dissolved-state low-coordination copper-cyanogen complex to react to generate insoluble CuS crystals by adjusting the pH value and adding the composite vulcanizing agent; and (4) magnetic seed enhanced separation: carrying out magnetic separation by adopting modified magnetic seeds and a low-intensity magnetic separator, separating CuS magnetic flocs from the wastewater, and finally obtaining purified tail liquid. According to the closed-loop process, copper in the copper-cyanogen complex wastewater can be efficiently removed and recovered, the purified tail liquid can be reused for cyanidation leaching operation, the unit consumption of sodium cyanide is remarkably reduced, the leaching rate of gold and silver is increased, and zero discharge of wastewater and full recovery of copper resources are truly achieved.

The invention provides a sulphide ore alkaline desulfurization and cyanidation gold leaching agent system and a method for extracting gold through the sulphide ore alkaline desulfurization and cyanidation gold leaching agent system, and belongs to the technical field of hydrometallurgy. According to the method, a ternary agent system consisting of potassium ferricyanide, low-concentration sodium cyanide and thioguanosine is constructed. An efficient'oxidation-inhibition 'synergistic system is formed between the auxiliary desulfurization agent potassium ferricyanide and the thioguanosine. The rapid and selective oxidation of potassium ferricyanide is smoothly carried out under the synergistic effect of thioguanosine, minerals are thoroughly decomposed, and the surface keeps high activity; meanwhile, due to the existence of the thioguanosine, the local microcell passivation risk and catalytic electron transfer can be eliminated more directionally. The sodium cyanide and the sodium cyanide complement each other, it is jointly guaranteed that the exposed gold can be smoothly and efficiently leached through follow-up low-concentration sodium cyanide, finally, the total consumption of reagents is reduced, environmental pollution is reduced, and meanwhile high-recovery-rate extraction of the gold in the sulfide ore difficult to treat is achieved.

The invention relates to the field of metallurgy and chemical engineering, in particular to a heap leaching gold extraction method for low-grade gold sulfide ore. Comprising the following steps that an anti-seepage bottom mat is laid on a dump leaching site; pre-treating the sulfide gold ore by using quick lime; ore crushing; ore is poured and piled on the upper portion of the bottom pad; spraying is conducted on the top of the ore heap and a side slope frame pipe, the gold-containing pregnant solution is collected, and the spraying solution is a sodium cyanide solution; and recovering gold from the gold-containing pregnant solution. According to the heap leaching gold extraction method provided by the invention, the quicklime is adopted to carry out pretreatment (iron removal, desulfurization and arsenic removal) on the sulfide gold ore, and then processes of subsequent ore crushing, heap building, spraying, adsorption and the like are carried out, so that the difficult problems of heap leaching utilization and popularization of low-grade sulfide ore resources are solved.

The present invention relates to a method for producing a composite adsorbent of ferrocyanide of a transition metal in the matrix of silica gel comprising the following steps: (i) preparing a first aqueous composition comprising at least the mixture of a sodium or potassium ferrocyanide with a sodium silicate solution so as to obtain the dissolution of salts; (ii) preparing a second composition comprising the mixture of at least: a transition metal salt chosen from one or more of the following compounds: nickel, copper, zinc, cobalt, and an inorganic acid; (iii) mixing the first aqueous composition with the second composition until a suspension is obtained; (iv) adding an inorganic acid or base so that the suspension obtained at the end of step (iii) has a pH ranging from 4 to 9;(v) demixing the suspension obtained at the end of step (iv) so as to obtain a precipitate within a liquid phase; (vi) separating said precipitate, rinsing and drying the precipitate, so as to obtain a solid precipitate, characterized in that the first aqueous composition comprises a soluble rubidium or cesium salt, and the second composition further comprises a soluble metal salt chosen from one or more of the following compounds: aluminum, titanium, zirconium.;

This invention discloses a method for recycling and reusing cyanide silver plating wastewater. The method includes four steps: separation of silver ions and cyanide, concentration of the silver-containing solution, cyanide concentration, electrolysis and residual liquid recycling, and reuse of reclaimed water. This method achieves the separate recycling and reuse of silver, cyanide, and water. The silver-containing solution is electrolyzed to obtain metallic silver, the cyanide concentrate's main component is sodium cyanide or potassium cyanide solution, and the reclaimed water with a conductivity below 20 μS / cm is reused in the production line. This method not only maximizes resource utilization and reduces wastewater discharge, but also separates most of the cyanide from the silver-containing solution during electrolysis, making the electrolysis process safer. Furthermore, the residual liquid after electrolysis can be recycled multiple times for the separation and concentration of silver ions and cyanide.

The utility model discloses a high-concentration sodium cyanide wastewater treatment system, which is characterized in that the whole system is in an under-pressure closed state, no waste gas is generated in the process, the safety can be ensured, cyanogen breaking is carried out through alkaline hydrolysis and hydrogen peroxide oxidation in the reaction process, the cyanogen breaking effect is obvious, the concentration of sodium cyanide in wastewater can be reduced from 20000 mg / L to 0.5 mg / L, and the concentration of sodium cyanide in wastewater can be reduced from 20000 mg / L to 0.5 mg / L. And through two-stage under-pressure heat exchange and one-stage normal-temperature heat exchange in the heat recovery device, waste heat energy is utilized to the maximum extent, and the energy-saving effect is obvious.

The invention belongs to the technical field of sodium ion batteries, and particularly relates to a Prussian blue sodium battery positive electrode material and a preparation method thereof.The preparation method comprises the steps that anhydrous sodium ferrocyanide, anhydrous manganese sulfate and a NaA molecular sieve are mixed and preliminarily ground, and a precursor mixture is obtained; placing the precursor mixture in a planetary ball mill for ball milling to obtain a primary reaction product; and washing the preliminary reaction product, and carrying out vacuum drying to obtain the Prussian blue sodium battery positive electrode material. The method is low in material loss and short in generation period, and the prepared Prussian blue sodium battery positive electrode material is low in crystal water content and has good cycle stability.

The invention relates to an environment-friendly gold leaching agent and a gold leaching method, and belongs to the technical field of gold leaching. The environment-friendly gold leaching agent comprises sodium cyanurate and guanidine salt. The gold leaching agent provided by the invention has a good gold leaching effect, is high in gold selectivity, does not contain traditional highly toxic sodium cyanide, is small in environmental pollution, and is green and environment-friendly.

The invention belongs to the technical field of medicine synthesis, and discloses a preparation method of a sodium nitroprusside raw material medicine. According to the method, weak acid is adopted for catalysis, the effect of remarkably reducing generation of toxic substances such as cyanide and nitrogen dioxide is achieved by controlling the material dripping speed and the dripping pH, the reaction is mild, the technological operation is safe and controllable, and industrial production of the sodium nitroprusside raw material medicine is facilitated. According to the preparation method of some examples, silica gel filtration is used for post-treatment, the residual risk of impurities such as sodium ferricyanide, ferric ferrocyanide and ferric ferricyanide is reduced, and the purity of the raw material medicine is larger than or equal to 99.9% and is far superior to the requirements of pharmacopoeia of various countries.

The invention discloses a lanthanide-doped Prussian blue positive electrode material and a preparation method and application thereof, and the preparation method comprises the following steps: mixing and dissolving sodium ferrocyanide and lanthanide metal salt to obtain a mixed solution; and under a protective atmosphere, dropwise adding the mixed solution into a mixed chelating agent salt solution through a peristaltic pump, and reacting to obtain the lanthanide-doped Prussian blue positive electrode material. The lanthanide metal in the lanthanide-doped Prussian blue positive electrode material occupies the Na site, the single iron source coprecipitation method is adopted for synthesis, the process concentration is uniform, the synthesized positive electrode material has fewer defects, the material structure is stable, the rate capability is excellent, the specific capacity is high, and the application prospect is very good.

The present application relates to a process for producing synthetic ammonia by using hydrogen-containing tail gas, comprising the following steps: S1: sodium cyanide tail gas is pressurized, then heated and water-cooled. S2: the impurity-removed tail gas is desulfurized. S3: the desulfurized tail gas is mixed with chlor-alkali tail gas, the mixed gas is heated and deoxidized. S4: the deoxidized tail gas is pressurized and enters a PSA (pressure swing adsorption) device for pressure swing adsorption treatment, obtaining high-purity hydrogen. In the PSA device, dehydrating, carbon dioxide, methane, carbon monoxide and nitrogen adsorbents are sequentially arranged. The carbon dioxide adsorbent is activated carbon modified by carbonate and strong alkali, and the nitrogen adsorbent is 13X zeolite molecular sieve modified by Na + and Ba 2+ and Ca 2+ ion exchange. S5: nitrogen reacts with the high-purity hydrogen obtained in step S4 to generate ammonia. The present application can improve the adsorption capacity of the adsorbent for impurity gas, thereby reducing the replacement frequency of the adsorbent, prolonging the service period and service life of the adsorbent, and improving the production efficiency.

The invention discloses a kind of recycling polypropylene to prepare high-impact material and preparation method thereof, relate to the field of materials. When the present invention uses recycling polypropylene to prepare high-impact material, first, polypropylene is grafted with vinyl diphenylphosphine, then reacted with 1-(3-chlorophenyl)-2-propyn-1-ol, and then reacted with 6-(methyl formate) pyridine-3-boric acid to obtain modified polypropylene; Secondly, calcium carbonate pretreated with 3-aminopropyltrimethoxysilane and 3-thiophene carboxaldehyde are reacted, and thiophene, 6-(thiophene-2-yl) pyridine-2-carboxylic acid, and 6-(3-thienyl) pyridine-2-carboxaldehyde are polymerized on the surface of calcium carbonate to obtain modified calcium carbonate; Finally, recycled polypropylene, modified polypropylene, modified calcium carbonate, sodium cyanide, and bismaleimide are melt-blended, and then extrusion granulation is performed to obtain high-impact material; The high-impact material prepared by the present invention has good impact resistance, anti-aging performance and antibacterial performance.

The invention provides a method for synthesizing ethyl 4-cyano-3-hydroxybutyrate by a pure hydrocyanic acid method, which is characterized in that ethyl 4-chloro-3-hydroxybutyrate and hydrocyanic acid are used as raw materials, a biological enzyme is used as a catalyst, the pH value of a reaction solution is controlled to be 6.5-7.5, and the ethyl 4-cyano-3-hydroxybutyrate is synthesized; the hydrogen cyanide is used as a raw material, so that the cost of a sodium cyanide preparation process can be reduced, the consumption of sodium hydroxide can be reduced, and the treatment cost of pollutants (sodium salt) can be reduced. The method has the advantages of being high in reasonability, low in material loss and high in production efficiency. The ethyl 4-cyano-3-hydroxybutyrate prepared by the method has the yield of 80%, the content of more than or equal to 98.5% and the single impurity content of less than 0.5%.

The application discloses a preparation method of ammonium glufosinate, which comprises the following steps: adding diethyl malonate and liquid bromine into a first solvent to react to obtain intermediate I; adding the intermediate I, potassium phthalimide and a quaternary ammonium salt catalyst into toluene to react to obtain intermediate II; adding the intermediate II, potassium carbonate, 1,2-dibromoethane and a phase transfer catalyst into a second solvent to react to obtain intermediate III; adding the intermediate III and diethyl methyl phosphonite into toluene to react under argon to obtain intermediate IV; adding the intermediate IV into hydrochloric acid to react under reflux; cooling, precipitation, drying to obtain intermediate V; mixing the intermediate V with water, passing in ammonia and adjusting pH value; adding methanol and stirring to react; cooling, filtering and drying to obtain ammonium glufosinate. The method can avoid using sodium cyanide or hydrocyanic acid, and no large amount of difficult-to-separate ammonium chloride is generated, the content of the obtained ammonium glufosinate is 90% to 98%, and the total yield is greater than 68%.

The present invention discloses a Prussian blue-based sodium-ion battery positive electrode material, a preparation method, and applications thereof. The method comprises: mixing sodium ferrocyanide, oxalate, and a non-aqueous solvent, subjecting the mixture to a ball-milling reaction, and washing the product after the ball-milling reaction to remove unreacted raw materials and a portion of sodium oxalate generated by the reaction, thereby obtaining the Prussian blue-based sodium-ion battery positive electrode material. The present invention can synthesize Prussian blue-based compounds with low defects and low interstitial water molecule content, thereby improving the sodium storage performance and capacity utilization of such materials; it also reduces the probability of side reactions in the electrolyte causing cell bloating. In addition, the use of oxalate-based raw materials can also generate a sodium oxalate-based positive electrode sodium supplement during the synthesis of the Prussian blue-based compound, thereby replenishing sodium ion loss caused by SEI film formation or other side reactions during the initial charge.

The present invention relates to the technical field of organic chemistry, and discloses a preparation method of 9-phenanthrene formic acid, wherein the preparation method comprises the following steps: using phenanthrene as a main raw material, iron bromide or zinc bromide as a catalyst, reacting with hydrobromic acid and hydrogen peroxide at 20 to 50 ° C to generate 9-bromophenanthrene, 9-bromophenanthrene reacts with cyanide under a catalyst to generate 9-nitrile phenanthrene, and then hydrolyzing under alkaline conditions to obtain 9-phenanthrene formic acid. The present invention uses cheap and readily available raw materials such as phenanthrene, hydrobromic acid, hydrogen peroxide and sodium cyanide to prepare 9-phenanthrene formic acid, with low production cost, high conversion rate, good product quality, mild reaction conditions, low equipment requirements, and can be used for large-scale industrial preparation of 9-phenanthrene formic acid.

The application provides a synthesis method of 4-(hydroxymethyl phosphine) 2-carbonyl butyric acid, comprising the following steps: a) mixing acryloyl chloride, a first solvent, a polymerization inhibitor, a catalyst and sodium cyanide, performing a substitution reaction, and obtaining an acryloyl cyanide intermediate after reduced pressure distillation; b) mixing the acryloyl cyanide intermediate obtained in the step a) with hydrochloric acid and a polymerization inhibitor, performing a hydrolysis reaction, and obtaining 2-carbonyl-3-butenoic acid crude product after purification treatment; c) mixing the 2-carbonyl-3-butenoic acid crude product obtained in the step b) with a second solvent and methyl phosphinite, performing an addition reaction, recovering the solvent after water separation and extraction, and obtaining a ketonic acid ester solution; and d) adding hydrochloric acid to the ketonic acid ester solution obtained in the step c) to adjust the pH to be less than or equal to 3, performing a hydrolysis reaction, and obtaining 4-(hydroxymethyl phosphine) 2-carbonyl butyric acid after purification. The synthesis method selects inexpensive acryloyl chloride as a raw material, has mild reaction conditions, is simple to operate, has low production cost, is easy to realize industrialization, and has high yield.

The invention relates to a method for producing alkali metal cyanide briquettes, in particular sodium cyanide briquettes, the method comprising: i) providing an aqueous suspension containing alkali metal cyanide crystals; ii) separating the alkali metal cyanide crystals from the suspension as a moist mass by means of a discontinuously operating centrifuge; iii) temporarily storing the separated moist mass in a buffer container; and iv) feeding the separated moist mass from the buffer container into a continuously operating briquetting machine, in which the moist mass is pressed to form the alkali metal cyanide briquettes. The invention also relates to a device for producing alkali metal cyanide briquettes, in particular sodium cyanide briquettes, in accordance with the method according to the invention.

The application provides a method for detecting the titer of vitamin B12 in a fermentation liquor. The method comprises the following steps: preparing a potassium dichromate solution, a hydrochloric acid solution and a potassium dihydrogen phosphate solution, mixing the three solutions with the vitamin B12 fermentation liquor under certain conditions to generate cyanocobalamin, and then testing the titer of the cyanocobalamin by using a high performance liquid chromatography. The titer of the vitamin B12 detected by using the method is consistent with the titer detected by using a sodium cyanide method. The operation method greatly reduces the safety risk of an analyst caused by using the sodium cyanide, and the operation method is simple, easy to manage in a laboratory and can save the testing cost.

The invention belongs to the technical field of energy materials, and particularly relates to preparation and application of a high-crystallinity long-life Prussian blue and analogue positive electrode material thereof. Aiming at the defects in the prior art, the invention provides the preparation method of the high-crystallinity long-life Prussian blue and the analogue thereof, which comprises the following steps: 1) mixing soluble transition metal M salt and a solvent to obtain a solution A; 2) mixing sodium ferrocyanide salt, sodium salt and a solvent to obtain a solution B; adding a complexing agent or / and an acid for regulating and controlling the chelating ability into the solution A, adding a complexing agent or / and an acid for regulating and controlling the chelating ability into the solution B, and controlling the total molar ratio of the complexing agent to the acid for regulating and controlling the chelating ability in the solution A and the solution B to be (20-1): 1; and 3) dropwise adding the solution A into the solution B, reacting, aging, centrifuging, washing and drying to obtain the Prussian blue and the analogue thereof. The method disclosed by the invention greatly widens the selection range of the chelating agent in the production process of the Prussian blue analogue positive electrode.

The valve comprises a valve body, a convex ring is arranged outside the valve body, the part, located at the bottom of the convex ring, of the valve body is wedge-shaped, a plurality of L-shaped locking blocks are arranged on the convex ring, one side of each locking block is in sliding connection with the convex ring, a magnetizer is fixed to the other side of each locking block, and the magnetizers and the locking blocks form a U-shaped structure. The valve electroplating process comprises the following steps: step 1, immersing a product into a cleaning furnace in which a deoiling agent is mixed with water, and leaching with clear water; 2, immersing in a nitric acid solution, and leaching with clear water; step 3, immersing into a cyanogen copper cylinder containing cuprous cyanide, sodium cyanide and potassium sodium tartrate, and rinsing with clear water; step 4, immersing into an acid copper cylinder containing copper sulfate, sulfuric acid and chloride ions, and rinsing with clear water; step 5, immersing into a bright nickel cylinder containing nickel sulfate, nickel chloride and boric acid, and rinsing with clear water; step 6, immersing in a cylinder containing chromic acid and chromium sulfate, and rinsing with clear water; and 7, the electroplating quality is inspected. The valve has the beneficial effect that the surface of the valve is not easy to corrode and rust.

The application discloses a kind of low-defect manganese-based prussian blue under solid-liquid dynamic balance fast preparation method, comprising the following steps: S1, sodium citrate is dissolved in deionized water, then add manganese acetate and ascorbic acid, form the solution A containing manganese complex;Wherein, the molar ratio of sodium citrate, manganese acetate and ascorbic acid is (4.5-5.5): 1:(0.3-0.4);S2, sodium ferrocyanide is added to deionized water, stirring is formed at a set temperature containing unsolved sodium ferrocyanide solid supersaturated suspension B;Wherein, the addition amount of sodium ferrocyanide is far more than its saturated solubility at the temperature, so that the system maintains solid-liquid two-phase equilibrium state;Crystalline integrity is higher: thanks to "whole process dynamic saturation" environment, the manganese-based prussian blue prepared by the application has more obvious monoclinic phase characteristics (corresponding XRD double peak is obvious, intensity is obvious, signal-to-noise ratio is good) compared with comparative document, lattice vacancy and coordination water content are significantly lower than comparative document scheme, and electronic conductivity is increased by nearly 50%.

The invention relates to an environment-friendly gold leaching agent and an application method of the environment-friendly gold leaching agent in arsenic-containing refractory gold ore, and belongs to the technical field of hydrometallurgy. Preparing an auxiliary mixing agent from sodium carbonate and sodium sulfate according to a molar ratio of 4: 1 to 6: 1, and reacting for 2-4 hours at 200-300 DEG C under the action of excessive nitrogen to prepare a thiocyanogen complex; and cooling and crushing to obtain thiocyanogen complex powder. The effective cyanide concentration is 3%-5%, and cyanide volatilization and environmental pollution are remarkably reduced. According to the method, under the synergistic effect of biological pre-oxidation, the gold leaching efficiency is guaranteed, meanwhile, the unit dosage of sodium cyanide is remarkably reduced, the problems that a traditional cyanide method is high in toxicity and low in recovery rate of wrapped gold in the refractory gold ore are solved, and the method has high efficiency, environmental protection property and industrial feasibility and is suitable for green gold extraction of the high-arsenic and high-sulfur gold ore.

The invention relates to the field of compound preparation, and discloses a method for preparing alkali metal ferrocyanide by using iron powder as an iron source through a mechanochemical method, and the method comprises the following steps: mixing the iron powder with a solution containing alkali metal cyanide to obtain a mixture, and enabling the water content of the mixture to be not more than 50wt%, the alkali metal cyanide comprises sodium cyanide or potassium cyanide, the reaction time is short, the reaction temperature is low, the process of treating the raw materials in advance is omitted, hydrolysis of the sodium cyanide is reduced, side reactions are reduced, a small amount of NH3 is released in the complexing reaction process, and the method is suitable for industrial production. The yield is high, sulfate containing ferrocyanide is not produced as a byproduct, and unreacted metal residues are recycled. Compared with a traditional method, the method disclosed by the invention is low in production cost and high in added value of products, and has a relatively good industrial prospect.

The invention relates to a preparation method and application of a Prussian blue material, and belongs to the field of new battery materials. The method aims to solve the technical problems that an existing preparation method is long in reaction time and harsh in process condition and has the risk of cyanide generation. A mixed solution prepared from a chelate and a cyanogen source is placed in a microwave reactor, the temperature is raised to 20-180 DEG C at the speed of 1-10 DEG C / min, heat preservation is conducted for 1-60 min, the Prussian blue material is prepared, the chelate is selected from glycine and ethylenediamine tetraacetic acid, and the cyanogen source comprises compounds such as sodium ferrocyanide. The performance of the material is synergistically optimized by adding a sodium source, a reducing agent and a surfactant. According to the preparation method, the process energy consumption is low, the risk of cyanide generation is avoided, the obtained material shows excellent performance in a sodium ion battery, 67.39% of capacity is kept after 400 times of circulation under the current density of 200mA / g, and a rate test shows that the discharge specific capacity of 78.92 mAh / g is still kept at the discharge specific capacity of 800mA / g. According to the invention, efficient and safe preparation of the Prussian blue material and large-scale application of the Prussian blue material in energy storage devices are realized.

The present invention relates to the field of protein extraction production technology, and proposes an energy-saving and emission-reduction process for VB12 extraction, comprising the following steps: S1, subjecting a VB12 hydrolyzate to plate-and-frame filtration to obtain a first filtrate; S2, subjecting the first filtrate to low-pressure, lateral-flow tubular fine filtration to obtain a fine filtrate; S3, adsorbing the fine filtrate with a protein-targeted adsorbent to obtain a high-resolution solution; S4, subjecting the high-resolution solution to medium-pressure nanofiltration to obtain a nanofiltration concentrate, and then adsorbing protein impurities therein with a protein-targeted adsorbent to obtain a low-protein nanofiltration concentrate; S5, adding sodium cyanide to the low-protein nanofiltration concentrate for conversion to obtain a conversion supernatant; S6, subjecting the conversion supernatant to adsorption with an adsorption column, washing with water, and decomposing with acetone to obtain a secondary hydrolysis-refined concentrate; S7, subjecting the secondary hydrolysis-refined concentrate to chromatography and evaporation and crystallization to obtain pure VB12. The above technical solution solves the problems of high investment, high energy consumption, and difficulty in detoxification treatment in the prior art of VB12 production.

The invention discloses a vacancy content controllable Prussian blue crystal as well as a preparation method and application thereof, and belongs to the technical field of material synthesis. In order to solve the technical problems that the vacancy content of a prussian blue material is difficult to accurately control and a vacancy-free material is difficult to prepare, the invention provides a series of prussian blue crystals with controllable vacancy content, and the preparation method comprises the following steps: mixing sodium ferrocyanide, a complexing agent, a sodium salt and water to obtain a solution A; mixing soluble manganese salt, soluble ferrous salt, a complexing agent, sodium salt and water to obtain a solution B; and controlling the sodium ion concentration and the reaction atmosphere and temperature, adding the solution A into the solution B, reacting, and aging to obtain the Prussian blue crystal. According to the method, the sodium ion concentration, the reaction atmosphere and the temperature are regulated and controlled by changing the addition amount of the sodium salt and the like, and the crystal growth speed and the ion transmission speed in the coprecipitation reaction are controlled, so that the purpose of accurately controlling the vacancy content is achieved, and a material without vacancy and first-stage crystal water can be prepared.

The invention discloses a sodium cyanide concentration online monitoring device with a good anti-blocking effect for a leaching section, and belongs to the technical field of sodium cyanide concentration monitoring. The sodium cyanide concentration online monitoring device comprises a detection pipeline, supporting legs are arranged at the corners of the lower side of the detection pipeline, a dismounting plate is arranged on the front side of the detection pipeline, and a first flow guide pipeline is arranged above the left side of the detection pipeline; a centrifugal filter assembly is arranged in the first flow guide pipeline, a second flow guide pipeline is arranged on the lower side of the first flow guide pipeline, one end of the second flow guide pipeline is connected to the top of the left side of the detection pipeline, and flow guide assemblies are arranged in the second flow guide pipeline and the detection pipeline. Through the double filtering design of the centrifugal filtering assembly and the filter plate filtering assembly, large-particle impurities and small-particle impurities in liquid can be effectively removed, the monitoring probe is prevented from being blocked by the impurities, and long-term stable operation of the monitoring device is ensured.