2246 results about "Precious metal" patented technology

The invention discloses a preparation process of a modified porous carbon material catalyst. The preparation process comprises the following steps: (1) mixing and calcining a biomass precursor and a template agent to prepare graded porous carbon; (2) low-frequency plasma pretreatment and high-frequency plasma fluorination modification are adopted; (3) introducing the pulse plasma into a nitrogen doping site; (4) spraying ionic liquid and activating H2 plasma to form a B / F co-doped layer; and (5) loading alloy nanoparticles such as PtRu through pulse electrodeposition. According to the obtained catalyst, biomass derived porous carbon serves as a carrier, a fluorine / nitrogen co-doped active layer is constructed on the surface of the carrier through multi-frequency plasma synergistic modification and ionic liquid auxiliary modification, superfine precious metal nanoparticles are loaded, the hydrogen evolution overpotential of the catalyst is smaller than or equal to 28 mV under the current density of 10 mA / cm < 2 >, the activity attenuation is smaller than 5% after 1000 times of circulation, and the catalyst has a good catalytic activity. The water electrolysis hydrogen production device is suitable for a large-scale water electrolysis hydrogen production device.

A system and associated method and service for providing a platform that enables members to transfer, receive, or otherwise exchange cash in various international denominations and commodities, such as precious metals (e.g., gold, silver, etc.), in a mobile highly secured telecommunications environment. The system is capable of delivering cash instantly between two or more users by allowing the exchange of secure transactions between system and cash dispensing machines (ATMs). Users may pay, receive, exchange, deposit, transfer, pay bills, exchange currency, retrieve cash, deposit cash and create accounts based on the mobile phone number or a system generated code.

The invention discloses a carbon nitride-based composite material as well as a preparation method and application thereof. The carbon nitride-based composite material comprises a non-metal doped carbon nitride carrier and a noble metal, wherein the noble metal exists in the carrier in an element doping form and / or is loaded on the carrier in an oxide form; the precious metal is one or more of Pt, Pd, Au and Ru, and the nonmetal is one or more of P, S and I. According to the carbon nitride composite material disclosed by the invention, noble metal is utilized to modify carbon nitride, the number of surface active sites is increased, the electron and chemical structures of an active center are adjusted, and meanwhile, generation and migration of photo-generated charges are promoted. Meanwhile, the surface of the carbon nitride composite material is modified by non-metallic elements, so that adsorption and activation of reactant H2O molecules are effectively promoted. The catalyst disclosed by the invention is simple in preparation process, good in repeatability and easy for large-scale production.

The invention discloses a high-bismuth slag and precious lead co-processing and efficient recycling method, and belongs to the technical field of non-ferrous metallurgy. High-bismuth slag and precious lead are mixed to obtain impurity-removed precious lead through impurity removal processes such as plug-blow antimony removal, liquation copper removal and tellurium removal by adding agents, and the impurity-removed precious lead is subjected to an oxidation refining process to obtain gold-silver alloy to recover precious metal. Bismuth and lead are similar, silver can be infinitely dissolved in a molten state, and the silver trapping agent has good silver trapping capacity. The high-bismuth slag and the precious lead are mixed to greatly reduce the temperature of a system, volatilization and unknown loss of metal such as Ag are reduced, energy consumption is remarkably reduced, the production cost is reduced, the recovery rate of metal such as bismuth, antimony and silver is increased, and the production efficiency is improved. The obtained molten slag is used for smelting high-bismuth slag, the obtained soot is used for smelting crude antimony, and efficient cyclic utilization of rare and precious metal resources is achieved.

The invention discloses a Ti / IrO2-SnO2-SbO2 gradient active coating anode with low cost and high stability and a preparation process of the Ti / IrO2-SnO2-SbO2 gradient active coating anode. The gradient active coating is characterized in that the gradient active coating is composed of 3-5 layers, the total thickness is 5-15 microns, the thickness of each layer is 1-5 microns, the molar percentage content of iridium in a bottom layer is 0-5%, the sum of the molar percentage content of tin and antimony is 95-100%, the molar percentage content of iridium in a surface layer is 10-20%, the sum of the molar percentage content of tin and antimony is 80-90%, and the thickness of each layer is 1-5 microns. The molar percentage content of iridium from the bottom layer to the surface layer is sequentially increased from 2% to 10%, the molar percentage content of tin and antimony is sequentially reduced from 2% to 10%, and the total iridium loading amount in the gradient active coating is 0.05-0.2 mg / cm < 2 >. The preparation method comprises the three steps of titanium substrate pretreatment, precursor salt alcohol solution preparation and gradient active coating preparation. By adopting a gradient coating mode, the thermal stress between the coating and the titanium substrate in the preparation process is remarkably reduced, the consumption of noble metal is reduced, the oxygen evolution activity of the anode is improved, and the service life of the anode is prolonged. The method is simple to operate and low in cost, and has remarkable industrialization advantages.

The invention relates to economical corrosion-resistant 5Cr80 rare earth oil well pipe steel and a preparation method thereof, belongs to the technical field of corrosion-resistant oil well pipe steel for petroleum engineering, and aims to solve the problems that the cost is high due to addition of precious metals such as Mo and Ni in existing medium Cr steel, pitting corrosion is induced by inclusion of MnS, and a rare earth treatment process is unstable. The oil well pipe steel is prepared from the following chemical components in percentage by mass: 0.05 percent to 0.08 percent of C, 0.3 percent to 0.50 percent of Si, 0.80 percent to 1.5 percent of Mn, less than or equal to 0.01 percent of P, less than or equal to 0.0020 percent of S, less than or equal to 0.0020 percent of O, 0.0050 percent to 0.0350 percent of Ce, 4.5 percent to 5.5 percent of Cr, less than or equal to 0.035 percent of Al, 0.020 percent to 0.030 percent of V and the balance of Fe and inevitable impurities. The yield strength of the oil well pipe steel is larger than or equal to 580 MPa. The economical corrosion-resistant 5Cr80 rare earth oil well pipe steel which is low in cost and free of a Mo-Ni component system is used for replacing a traditional high-alloy pipe in a harsh oil and gas well environment containing high Cl <-> and CO2, and the economical corrosion-resistant 5Cr80 rare earth oil well pipe steel is suitable for batch production of corrosion-resistant oil well pipes of deep wells, ultra-deep wells and sulfur-containing and CO2-containing complex working conditions.

The invention discloses a coating and a method for recovering precious metals in a physical vapor deposition process. The coating mainly comprises a silver coating positioned on the lower layer and an organic silicon modified layer positioned on the surface of the silver coating. Before precious metal is recycled, the coating is prepared on the surface of the position where precious metal needs to be recycled in the physical vapor deposition process, after physical vapor deposition is completed, an adhesive tape is adopted to be pasted to the surface of the coating, and then the precious metal is stripped from the surface of the coating in a mode of tearing the adhesive tape; or scraping the surface of the coating by adopting a tool, so that the noble metal is stripped from the surface of the coating, and stripped noble metal chips are collected; and finally, the adhesive tape with the precious metal or the collected precious metal scraps are heated, and the precious metal is recycled from a heating product. According to the method, efficient stripping and efficient recycling of the precious metal can be achieved, the coating has no influence on physical vapor deposition equipment and the technological process, and the method is simple in technology, high in operability, environmentally friendly, free of pollution and high in economical efficiency when the precious metal is recycled and can be applied to the recycling process of the precious metal on a large scale.

The invention relates to the technical field of precious metal recovery, in particular to a process for separating precious metal from copper-nickel smelting waste, which comprises the following steps: crushing and grading the waste, adding a sulfuric acid solution containing etidronic acid, leaching, and washing, drying and crushing filter residues to obtain a pretreated material; mixing the pretreated material with a sodium peroxide-sodium carbonate composite flux, roasting, leaching with water, and filtering to obtain a filter residue B; adding a leaching agent containing hydrochloric acid, sodium chlorate and 1, 2-cyclohexanediamine tetraacetic acid into the filter residue B according to the ratio of 1: 3-1: 5, and filtering to obtain filtrate C and filter residue C; adjusting the pH value of the filtrate C to 1.5-2.5, adding an ethanol solution of sodium N, N-diethyldithiocarbamate, precipitating, washing and calcining to obtain sponge palladium; adding ammonium chloride into the filtrate D, precipitating and calcining to obtain sponge platinum; and leaching the filter residue C by using a hydrochloric acid-chloroauric acid mixed solution containing diphenylthiourea, and replacing and calcining zinc powder to obtain crude gold. According to the process, the leaching rates of platinum, palladium and gold and the product purity are greatly improved; flux and reagent systems are optimized, consumption and energy consumption are reduced, waste liquid treatment is matched for up-to-standard discharge, and efficient resource recovery and environment-friendly cooperation are achieved.

The invention provides a wet purification process suitable for silicon and precious metal of a waste photovoltaic laminated piece, which comprises the following steps of: immersing a waste crystalline silicon battery piece into a NaOH solution, and removing an aluminum wire on the surface of the crystalline silicon battery piece to obtain a dealuminized crystalline silicon piece; the dealuminated crystal silicon wafer is subjected to acid pickling, and a silver-removed crystal silicon wafer and silver leaching liquid are obtained; removing impurities from the silver-removed crystal silicon wafer through a hydrofluoric acid solution to obtain a high-purity crystal silicon wafer; and extracting the silver elementary substance from the silver leachate through a hydrazine hydrate reduction method. According to the wet purification process, the waste crystalline silicon battery piece can be subjected to high-purity recovery, and the high-purity crystalline silicon wafer and the silver elementary substance can be obtained.

The invention belongs to the technical field of chemical energy, and particularly relates to an ultralow-potential-difference zinc-air battery containing a copper cluster axial coordination iron monatomic catalyst. Benzimidazole and 2-methylimidazole are synthesized into ZIF-7-NH2, the ZIF-7-NH2 reacts with Fe (NO3) 3.9 H2O and Cu (OAc) 2. H2O in an ion exchange mode to obtain FeCu-ZIF-7-NH2, a urea calcination product g-C3N4 is added, stirring is carried out to obtain Fe-ZIF-7-NH2 / g-C3N4, finally, sintering is carried out under argon to obtain g-SAFe-Cin, the ORR activity and the OER activity of the catalyst are remarkably enhanced by constructing the copper cluster axial coordination iron monatomic catalyst, and the catalyst has the advantages of being high in catalytic activity, high in catalytic activity and high in catalytic activity. And the performance of the assembled zinc-air battery in the charge-discharge cycle is improved. Non-noble metal and a low-cost carbon source are used as raw materials, the synthesis cost of the catalyst is reduced, the yield is high, the preparation period is short, and large-scale commercial application potential is achieved.

This invention belongs to the field of high-value utilization technology of biomass resources, and discloses a method for catalyzing the depolymerization of lignin into phenolic compounds using a RuNiZn / Nb2O5 catalyst. The method includes: uniformly mixing the RuNiZn / Nb2O5 catalyst, lignin-containing biomass feedstock, and water; stirring under hydrogen atmosphere to carry out the depolymerization reaction; after the reaction, cooling to room temperature and performing solid-liquid separation; evaporating the solvent to obtain the hydrogenated depolymerization product containing monophenols. In this invention, the RuNiZn / Nb2O5 catalyst employs a technique of replacing precious metals with various non-precious metals, which improves the catalyst's reactivity and reduces the amount of precious metals used. This increases the yield of lignin depolymerization products, provides milder depolymerization reaction conditions, and ultimately significantly reduces the catalyst preparation cost and the energy cost of the lignin depolymerization process.

The invention discloses a method for recovering precious metal from refining wastewater, and relates to the technical field of wastewater resourceful treatment. Comprising the following steps: adding a porous carbon-based composite material into the acidic silver-containing refining wastewater, and stirring for adsorption to obtain an adsorption solution; the porous carbon-based composite material adsorbing the silver ions is recycled in a filtering or centrifugal separation mode; the porous carbon-based composite material adsorbing the silver ions makes contact with a desorption agent, desorption treatment is conducted, and a regenerated porous carbon-based composite material and a silver-containing desorption solution are obtained through separation; and a reducing agent is added into the silver-containing desorption solution, and silver ions are reduced into elemental silver to be recycled. The precious metal silver in the refining wastewater is recovered by adopting an adsorption method, and the recovery rate of the silver is relatively high.

Industrial kiln flue gas noble metal purification and resource utilization equipment and method, belong to flue gas treatment technical field. In view of the problems of low purification efficiency, difficult noble metal recovery and secondary pollution of spray liquid in prior art, the equipment is composed of spray tower and resource utilization device: the exhaust disc and multilayer rotating disc are arranged in the spray tower, the flue gas is driven to rotate by arc groove to realize preliminary dispersion, and then is dispersed again through the exhaust hole of rotating disc, and the alkaline solution or chelating agent sprayed by spray pipe is matched, the purified flue gas is filtered by activated carbon layer and discharged. The resource utilization device includes a rotatable collection box, four collection pools are arranged in the collection box to alternately receive the spray liquid, a special-shaped convex disc is driven by a driving shaft to control the periodic lifting of the lifting plate, so that the cathode rod, the anode rod and the water inlet pipe are inserted into the collection pool for electrolysis recovery, and the noble metal is attached to the surface of the cathode rod. The equipment realizes the integration of flue gas dispersion, spray adsorption and electrolysis recovery, significantly improves the noble metal recovery rate and reduces the risk of secondary pollution.

The invention discloses a zeolite / silver / copper ternary inorganic nano antibacterial and antiviral material as well as a preparation method and application thereof. The preparation method comprises the following steps: preparing a mixed solution of a template agent and an anchoring agent, loading a metal precursor, adding a silicon source, performing hydrothermal crystallization and performing post-treatment. According to the zeolite / silver / copper ternary inorganic nano antibacterial and antiviral material disclosed by the invention, Ag-Cu bimetallic nanoparticles are formed by introducing copper nitrate and silver together, so that the catalytic activity, selectivity and stability of the zeolite / silver / copper ternary inorganic nano antibacterial and antiviral material are remarkably enhanced, and the dosage of noble metal silver can be reduced.

The invention relates to the technical field of preparation of catalysts, in particular to a titanium dioxide modified mesoporous nickel catalyst, a preparation process and application thereof, and the preparation method comprises the following steps: S1, preparing a titanium dioxide modified mesoporous silicon dioxide material; s2, nickel-based acid liquid is added into the titanium dioxide modified mesoporous silicon dioxide material, ultrasonic treatment is performed for 1 h after sufficient mixing, standing is performed for 24 h at the room temperature so as to perform the dipping process, and then the mixture is transferred into a drying oven and dried at the temperature of 110 DEG C; and S3, uniformly grinding the dried solid, putting a sample into a crucible, transferring the sample into a tubular furnace, introducing argon as a protective atmosphere, heating to 550 DEG C at a heating rate of 1 DEG C / min, and roasting for 6 hours to obtain the titanium dioxide modified mesoporous nickel catalyst. The method has relatively high industrial potential, can replace an expensive noble metal catalyst to be used for industrial production, and lays a certain technical foundation for realizing final industrial production of a carbon dioxide methane reforming reaction and integrating the reaction into a green energy storage system.

The invention provides a method for recovering platinum group metal from a waste automobile exhaust purification catalyst, and belongs to the field of precious metal recovery. The method comprises the following steps: carrying out crushing and impurity removal pretreatment on the waste catalyst to obtain solid residues; mixing the obtained solid slag with alkali liquor, and performing hot-pressing activation to obtain active slag; leaching the active slag by using an acid leaching system of hydrochloric acid-hydrogen peroxide-sodium chloride to obtain a leaching solution enriched with platinum group metals; adjusting the acidity of the leachate, adding a first adsorption material, selectively adsorbing platinum and palladium, and separating supernate and a platinum / palladium enrichment material; adjusting the acidity of the supernate, adding a second adsorption material, selectively adsorbing rhodium, carrying out solid-liquid separation, and collecting a rhodium enrichment material; respectively eluting and refining the platinum / palladium enrichment material and the rhodium enrichment material, and recovering platinum, palladium and rhodium; through the optimally designed recovery method of alkaline hot-pressing activation-mild acidic directional leaching-two-stage magnetic adsorption separation, efficient recovery of platinum, palladium and rhodium in the waste automobile exhaust catalyst is realized.

The invention relates to the technical field of biological aviation kerosene, and discloses a process for preparing biological aviation kerosene from waste grease. The method comprises the following steps: introducing waste oil into a hydrofining reactor, introducing hydrogen, carrying out a hydrodeoxygenation reaction under the catalysis of a hydrogenation catalyst, carrying out a reaction on the obtained hydrodeoxygenated oil in an isomerization pour point depressing reactor, and finally carrying out isomerization hot high-pressure separation treatment, isomerization cold high-pressure separation treatment and rectification tower segmentation to obtain the biological aviation kerosene. The specific surface area of a carbon matrix of the hydrogenation catalyst is large, the void structure is rich, a large number of Ni-Mo-P active catalytic centers can be exposed, precious metals such as platinum and ruthenium do not need to be added, the hydrodeoxygenation reaction efficiency of waste oil and fat is remarkably improved, the mass fraction of branched paraffin and cycloparaffin in biological aviation fuel is high, and the combustion performance is better.

The invention relates to a PEM ternary alloy catalyst for water electrolysis hydrogen production and a preparation method thereof, and belongs to the technical field of water electrolysis catalysts. 1-butyl-3-methylimidazolium tetrafluoroborate is introduced in the generation of a carrier manganese dioxide to increase the specific surface area of the carrier, fluorine doping and oxygen vacancy construction are realized on the surface of the carrier through hydrofluoric acid treatment, and then a metal precursor is dispersed through an ethylene glycol / water system; and finally, loading and alloying of the alloy nanoparticles are completed through hydrothermal reduction and heat treatment. The morphology and electronic structure of the carrier are synergistically regulated and controlled through ionic liquid and fluorine doping, the specific surface area and active sites are remarkably increased, strong interaction of metal and the carrier is achieved through ternary alloy component optimization, and the oxygen evolution reaction activity and stability of the catalyst and the precious metal utilization rate are effectively improved.

The utility model relates to the technical field of automobile parts, in particular to a three-way catalyst shell with a spiral guide plate, which comprises a three-way catalyst shell body, a reaction chamber is arranged in the three-way catalyst shell body, an air inlet and an air outlet are arranged at two ends of the three-way catalyst shell body, and the air inlet and the air outlet are communicated with the reaction chamber. An air guide structure communicated with the air inlet is arranged in the three-way catalyst shell body and comprises a flow guide column, a spiral flow guide plate and an air distribution plate, the spiral flow guide plate and the air distribution plate are sequentially, coaxially and fixedly connected to the flow guide column in the air inlet direction, and the outer wall of the spiral flow guide plate and the outer wall of the air distribution plate are closely attached to the inner wall of the three-way catalyst shell body. And a plurality of flow guide grooves are formed in the gas distribution plate, so that the problems that the performance of a traditional three-way catalyst is improved by improving the content of precious metal, and the manufacturing cost is sharply increased due to the increase of the content of the precious metal are solved.

The invention belongs to the technical field of catalyst development, and relates to a cerium oxide-loaded non-noble metal catalyst for a carbon dioxide methanation reaction and a preparation method of the cerium oxide-loaded non-noble metal catalyst. The method comprises the following steps: firstly, obtaining a cerium oxide carrier through a hydrothermal reaction, secondly, impregnating non-noble metal nitrate serving as a precursor on the cerium oxide carrier through an impregnation method, and carrying out ultrasonic treatment, drying, calcining and other steps to obtain the cerium oxide supported non-noble metal catalyst. The prepared catalyst is low in cost and has excellent carbon dioxide methanation catalytic activity. By controlling the loading capacity and the loading type of the non-noble metal, a multi-site synergistic effect is realized, more active sites are exposed, and finally, the catalytic performance of the cerium oxide loaded non-noble metal catalyst for catalyzing methanation of carbon dioxide at low temperature is improved.

The application discloses a kind of heteropoly acid assisted ball milling modified micron zero-valent iron particles, preparation method and application.The micron zero-valent iron particles are mainly prepared by mixing micron zero-valent iron, heteropoly acid and relatively cheap noble metal compound, and the specific preparation is that micron zero-valent iron, heteropoly acid and noble metal compound are placed in a ball mill jar and a specific atmosphere to carry out ball milling modification to obtain heteropoly acid modified ultra-low ruthenium loaded micron zero-valent iron particles.The particles provided by the application have extremely strong reaction performance on chlorinated hydrocarbons, and the performance does not attenuate for more than 30 cycles, and can achieve complete dechlorination on low concentration and high concentration chlorinated hydrocarbons, which has great water treatment application value.

The present disclosure is directed to a process that includes receiving a refractory precious metal-containing material comprising a preg-robbing material, determining a preg-robbing strength of the preg-robbing material relative to a sorbent, and a preg-robbing capacity after pressure oxidation and / or a preg-robbing capacity in the presence of a blanking agent, and, based on the preg-robbing strength of the preg-robbing material relative to a sorbent and the preg-robbing capacity after pressure oxidation and the preg-robbing capacity in the presence of a blanking agent, directing the refractory precious metal-containing material to a selected one of a plurality of unit processing operations for recovery of the precious metal in the refractory precious metal-containing material.

The invention relates to a preparation method of a carbon-based gold-containing bimetallic catalyst. The specific method comprises the following steps: carrying out secondary doping on eigenstate polyaniline, carrying out high-temperature pyrolysis in an inert atmosphere to obtain a heteroatom-doped carbon-based carrier, and changing the variety, the content and the distribution of heteroatoms on the carbon surface of the carrier by adjusting the variety and the content of acid. And preparing gold-containing bimetallic nanoparticles by using a colloid method, and depositing bimetallic particles by virtue of adsorption of the carbon carrier and bimetallic to obtain the carbon-based gold-containing bimetallic catalyst. Wherein the doping element can anchor and disperse the noble metal, and the introduced second metal can improve the hydrogenation activity of the catalyst. The catalyst is simple in preparation process, good in activity, excellent in selectivity and excellent in cycling stability, is particularly suitable for a reaction for preparing 4-chloroaniline through catalytic hydrogenation of 4-chloronitrobenzene, and has good application potential.

The invention discloses a multi-process energy consumption dynamic optimization control system for a precious metal processing production line, and relates to the technical field of precious metal processing, and the system comprises a data collection module which is used for collecting energy consumption data, process parameters and material flow data of equipment in real time; the optimization decision module comprises an energy consumption modeling unit and a dynamic optimization unit; the energy consumption modeling unit is used for establishing an energy consumption digital twin model for key equipment on a production line; the dynamic optimization unit is used for receiving and calculating a current optimal process parameter set value and an optimization instruction for adjusting the operation power and rhythm of equipment; and the driving execution module is used for realizing collaborative energy consumption optimization control of multiple processes. The method has the advantages that accurate energy consumption perception is achieved by constructing the energy consumption digital twinborn model, meanwhile, order merging is intelligently decided based on the material flow state and the order delivery time, and double optimization of overall energy efficiency improvement of the production line and comprehensive energy consumption cost is achieved.

The invention discloses a nitrogen / boron-doped non-noble metal-based material, a synthesis method thereof and application of the nitrogen / boron-doped non-noble metal-based material in a microbial fuel cell. According to the method, a carbon fiber brush is used as a substrate, urea and sodium borohydride are used as a nitrogen source and a carbon source respectively, and the nitrogen / boron doped non-noble metal-based material is synthesized through a hydrothermal method. The electrostatic interaction between graphene oxide and FeCoNi-LDH is utilized to realize tight combination, so that FeCoNi-LDH nanosheets are uniformly dispersed on the surface of the carbon fiber brush, and the problems that LDHs are easy to agglomerate and poor in conductivity are solved; in the boron / nitrogen co-doping process, an efficient electron transmission channel is constructed by adjusting the electronic structure of the composite material, and the material is endowed with excellent electron transmission capability and oxygen reduction performance. In an MFC (Microbial Fuel Cell) test constructed by taking a nitrogen / boron-doped non-noble metal-based material as a cathode, the output voltage and the maximum power density are several times of those of commercial Pt / C and a blank carbon fiber brush, and the carbon fiber brush has a wide application prospect in the field of microbial fuel cells.

The invention belongs to the technical field of lead ion detection, and particularly relates to a black phosphorus field-effect tube lead ion detector and a use method thereof. The detector comprises an insulating substrate, a gate electrode layer, a gate electrode insulating layer, a sensitive layer, a source electrode and a drain electrode. The gate electrode layer is arranged on the insulating substrate, and the sensitive layer is arranged on the gate electrode insulating layer; particularly, the sensitive layer comprises a black phosphorus material, and noble metal particles are arranged on the surface of the sensitive layer. According to the invention, black phosphorus is used as a sensitive material of the field effect transistor, the black phosphorus and lead ions have good chemical matching property, and a stable coordination effect is formed through surface phosphorus atoms and lead ions, so that the conductivity of a channel is obviously changed; in addition, precious metal particles are introduced to the surface of the black phosphorus sensitive layer, so that the selective adsorption capacity of lead ions is enhanced. In a word, high-selectivity and high-sensitivity electrical detection of lead ions can be realized, and a high-performance field-effect tube sensor platform is provided for rapid monitoring of heavy metal pollutants.

The invention discloses a micro-fine particle gold ore normal-pressure alkaline leaching pretreatment method based on sodium percarbonate reinforcement, and belongs to the field of precious metal metallurgy. The method comprises the following steps: adding an oxidizing agent sodium percarbonate in batches under the condition that air is filled into ore pulp, starting to monitor the oxidation potential and the pH value of a reaction system after adding, judging that the reaction reaches the end point when the sudden drop amplitude of the oxidation potential of the ore pulp within one hour is greater than or equal to 30mV and the pH value is increased by 0.3-0.5 unit, and stopping aeration to finish pretreatment; in the segmented oxidation process, the oxidation potential is controlled within the range of + 520 mV to + 550 mV by dynamically adjusting the air charging rate. According to the basic technical scheme, the gold leaching rate reaches 86.01%, the gold leaching rate reaches up to 88.92% through the optimized technical scheme, and the utilization rate of gold ore resources is remarkably increased.

The invention discloses a non-noble metal ORR catalyst and a preparation method thereof, and belongs to the technical field of electro-catalysis. The method comprises the following steps: (1) adding 5, 10, 15, 20-tetra (4-cyanophenyl) porphyrin and nickel salt into an organic solvent, and synthesizing a supramolecular crystal precursor UPC-S7 through solvothermal reaction; (2) carbonizing the supramolecular crystal precursor UPC-S7 in an inert atmosphere to obtain a Ni-coated NC material; (3) oxidizing the Ni-coated NC material in an oxygen-containing atmosphere to obtain a Ni / NiO-coated NC material; and (4) sequentially soaking and etching the Ni / NiO-coated NC material by using a nitric acid solution and an ammonia water solution, and then washing and drying to obtain the non-noble metal ORR catalyst. The prepared catalyst does not contain precious metal such as platinum, the raw material cost is remarkably reduced on the basis of ensuring the ORR activity and stability of the catalyst, and a new scheme is provided for solving the cost bottleneck of a fuel cell.

The invention discloses a harmless treatment device and process for lpcvd tail gas, the harmless treatment device comprises a treatment tower, the top and the right side of the surface of the treatment tower are respectively provided with a gas inlet pipe and a gas outlet pipe, the treatment tower is internally provided with a decomposition chamber, a cooling chamber and an adsorption chamber in sequence from top to bottom, the decomposition chamber is internally provided with a gas decomposition assembly, and the cooling chamber is internally provided with a cooling assembly. A gas adsorption assembly is arranged in the adsorption cavity; the gas decomposition assembly comprises a catalysis cylinder, and the surface of the gas inlet pipe communicates with a plurality of gas flow guide pipes at equal intervals in the circumferential direction. According to the harmless treatment device and process for the lpcvd tail gas, toxic gas is decomposed through a noble metal catalyst in the catalysis chamber, rapid cooling is achieved through the cooling cylinder and the cooling liquid circulating pipe, residues are purified through multiple layers of adsorbents in the adsorption cylinder, then toxic components in the tail gas can be efficiently decomposed, and the gas can be rapidly cooled and deeply purified; and the tail gas treatment capacity and efficiency of the device are improved.

The invention provides a method for preferentially extracting gold and silver from lead anode slime, and relates to the technical field of precious metal recovery, firstly, silver, antimony and other valuable metals in the lead anode slime are leached into a solution through catalytic oxidation leaching in the presence of a protective agent, and gold is enriched in residues; then, silver is selectively precipitated from the leachate, and silver precipitation residues and a valuable metal solution are obtained; and finally, valuable metals in the solution are recovered by adding a neutralizer and a precipitator, the obtained leaching mother liquor can be returned for leaching after being supplemented with hydrochloric acid, and the valuable metal precipitates are used for recovering antimony and bismuth. The method changes the traditional lead anode slime treatment thinking of first impurity removal and second refining, has the characteristics of high gold and silver direct recovery rate (greater than 99.5%), high reaction speed (total consumed time is less than 1 h), low cost and no generation of waste residue and wastewater, and is expected to solve the problems of long gold and silver recovery process, low direct recovery rate, capital overstock and difficult treatment of arsenic and antimony-containing smoke in the existing lead anode slime treatment method. The method has remarkable economic and environmental benefits and a good application prospect.