49 results about "Aqua regia" patented technology

The invention discloses a rapid enrichment-atomic absorption spectrum analysis method for low-content gold in gold ore, and relates to the technical field of gold ore analysis and detection.The rapid enrichment-atomic absorption spectrum analysis method comprises the following steps that an ore sample and a solid composite additive are mixed and roasted at the low temperature of 500-650 DEG C, and the additive contains alkali metal carbonate and zinc oxide; sulfur fixation, catalytic oxidation of organic carbon and stabilization of volatile elements can be synchronously realized; the method comprises the following steps: roasting gold-loaded activated carbon, dissolving the gold-loaded activated carbon in aqua regia to obtain a to-be-enriched solution, enabling the solution to pass through an adsorption column filled with modified activated carbon, pretreating the activated carbon with a 1-10% ammonium citrate solution to improve the selective adsorption capacity of the activated carbon on gold chloride complex ions, ashing the gold-loaded activated carbon, dissolving residues, fixing the volume, and measuring by using an atomic absorption spectrometry. According to the rapid enrichment-atomic absorption spectrum analysis method for the low-content gold in the gold ore, through cooperation of low-temperature roasting of the composite additive and selective adsorption of the modified activated carbon, the decomposition efficiency and enrichment selectivity of the ore difficult to treat are improved.

The invention relates to the technical field of detection, and particularly provides a method for determining the quality and purity of silver in a silver-gold-plated product. The determination method comprises the following steps: dissolving a surface gold plating layer of a silver-plated product with aqua regia, and then dissolving a silver chloride protective film on the surface of silver with ammonia water, so that the problem that the mass of silver cannot be accurately weighed after the gold plating layer in the product is removed is solved, and the problem that the silver chloride protective film hinders the dissolution of pure silver with nitric acid to influence the determination is also solved. Thiourea is further adopted to dissolve a complex of diamine and silver, the situation that when silver is dissolved, added nitric acid reacts with the complex of diamine and silver to generate silver chloride precipitates is prevented, an ammonium nitrate solution is used for washing thiourea, a flame atomic absorption spectrometry method is adopted for conducting mass correction on silver in the solution obtained after aqua regia gold is dissolved, and the total silver mass is obtained through calculation. According to the determination method, the quality and the purity of the silver in the silver-plated product can be relatively accurately obtained.

The application provides a method for preparing chloroplatinic acid based on waste platinum catalyst, comprising the following steps: pretreating the waste platinum catalyst to obtain crude metal platinum; dissolving the crude metal platinum in aqua regia to obtain a mixed solution; adjusting the pH of the mixed solution to 2.0-3.0, adding a first batch of reducing agent and dispersant, and reacting at 70-80 DEG C for 8-20 min to perform the first step reduction; adjusting the pH to 3.0-4.0, adding a second batch of reducing agent and dispersant, and continuing to react at 70-80 DEG C for 8-20 min to perform the second step reduction, so as to obtain a nano platinum system; separating to obtain monodisperse nano platinum; dissolving the monodisperse nano platinum in a hydrochloric acid-hydrogen peroxide system, the molar ratio of hydrochloric acid to hydrogen peroxide being 4:1-6:1, the dissolving temperature being 130-140 DEG C, and the dissolving time being 20-30 min, so as to obtain a chloroplatinic acid solution; and evaporating and crystallizing the chloroplatinic acid solution to obtain chloroplatinic acid crystals.

The invention discloses a method for preparing large-specific-gravity platinum powder from crude platinum, and belongs to the technical field of platinum group metal refining. According to the method, efficient purification of platinum and preparation of large-specific-gravity platinum powder are realized by adopting a combined precipitation method through the core steps of dissolving for liquid preparation, ammonium chloride precipitation, dissolving for impurity removal, acidification precipitation, reduction and the like. The method comprises the following specific steps: dissolving crude platinum with aqua regia to prepare a crude platinum solution, precipitating with ammonium chloride to generate ammonium chloroplatinate, dissolving with a special reagent to remove platinum group metal and base metal impurities, acidifying, precipitating, further purifying, and finally reducing with a liquid phase to obtain the large-specific-gravity platinum powder. The method is short in technological process, easy in process control, simple in operation equipment and suitable for large-scale production, the product purity is higher than 99.99% of sponge platinum requirements in the national standard GB / T-1419, the tap density is larger than 3.5 g / mL, and the method has wide application value in multiple fields of jewelry, chemical engineering, medicine, electronics, ceramics and the like.

The invention belongs to the technical field of recycling of rare and noble metal secondary resources, and discloses a method for preparing a tungsten compound and chloroplatinate from a waste catalyst and application of the method. The method comprises the following steps: (1) firing and crushing the waste catalyst, (2) reacting the waste catalyst with acid, (3) filtering and discarding filtrate, (4) reacting the precipitate with ammonia water, filtering to obtain an ammonium tungstate solution, and retaining filter residues; (5) concentrating the ammonium tungstate solution, crystallizing, separating and drying to obtain an ammonium paratungstate finished product; and (6) reacting the filter residues retained in the step (4) with aqua regia to prepare chloroplatinate. And (7) firing the ammonium paratungstate at a high temperature to obtain tungsten trioxide. According to the method, tungsten and platinum can be effectively separated from the carrier, and the recovery rate of rare and precious metals is increased.

A method for efficiently recovering iridium from organic coating liquids involves first mixing the coating liquid with an alkaline solution, stirring and reacting at room temperature, followed by solid-liquid separation. The solid is dried and dehydrated for later use, while the liquid is the supernatant. The supernatant is heated, and an alkaline solution is added and stirred to react. After sufficient settling, solid-liquid separation is performed again. The solid is dried and dehydrated, then ground together with the previously dried and dehydrated solid into powder. The powder is then calcined in a muffle furnace to obtain iridium and tantalum oxide powders. HF is added to the oxide powders to remove impurities such as Ta2O5, and solid-liquid separation is performed again. The solid is washed with water until neutral, dried and dehydrated, dissolved in aqua regia, and concentrated by heating to obtain chloroiridium acid. The method provided by this invention has a simple synthesis process, the supernatant after precipitation is free of iridium, the iridium loss rate is low, effectively reducing iridium loss in the organic liquid evaporation and concentration steps, and the HF removes tantalum, allowing direct dissolution of IrO2 in aqua regia, improving efficiency and reducing iridium loss during the process.

The invention relates to a sample pretreatment method for chromite microelement analysis. The method comprises the following steps: firstly, treating a sample to specific particle size distribution (Dv (50) lt, 5 [mu] m, Dv (90) lt, 20 [mu] m) through physical accurate grinding, and then adopting an improved two-step acid dissolution and digestion process: firstly, destroying main crystal lattices of minerals by using mixed acid, then, carrying out targeted dissolution on a residual insoluble phase by using aqua regia, and finally, carrying out chlorine removal treatment to obtain a solution to be detected. Through the synergistic effect of physical accurate grinding and secondary acid dissolution, almost complete decomposition of chromite is achieved, especially the extraction efficiency of key indissolvable elements such as Sc and Zn is improved by 20% or above, the accuracy and precision of ICP-MS analysis results are remarkably improved, and the problem that microelement measured value systematicness is low due to incomplete dissolution in a traditional method is solved.

The application provides a purification method of crude palladium, and belongs to the technical field of precious metal purification. In the application, the precious metals such as palladium in the crude palladium are dissolved by aqua regia, then the palladium ions are oxidized into high-valence palladium by an oxidizing agent, and then the high-valence palladium is precipitated into palladium salt by a precipitating agent, so as to improve the purity; then the palladium salt is dissolved by an inorganic solvent, so as to remove the impurities such as platinum, copper, iron and silver, thereby improving the purity of the palladium; the palladium ions in the filtrate are complexed by a first complexing agent, so as to obtain a sub-palladium salt precipitate, thereby removing the impurities and improving the purity of the palladium; then the palladium ions are further complexed by a second complexing agent, thereby further improving the purity of the palladium; and then electro-deposition is adopted, so as to ensure that the palladium ions are fully reduced into palladium powder, thereby improving the purity of the palladium. The experimental results show that the purity of the palladium powder obtained by the purification method is greater than or equal to 99.95%.

The invention belongs to the technical field of metallurgy, and particularly discloses a method for extracting gold from refractory iron-sulfur-gold concentrate by a wet process, which comprises the following steps: smelting the refractory iron-sulfur-gold concentrate by a pyrogenic process to obtain iron matte slag rich in gold and silver; the method comprises the following steps: crushing, ball-milling and slurrying the iron matte slag, introducing rich oxygen, carrying out pressure leaching under an acidic condition, and carrying out liquid-solid separation to obtain oxygen pressure leaching liquid and oxygen pressure leaching slag; cooling and crystallizing the oxygen pressure leachate to recover ferrous sulfate heptahydrate, and periodically vulcanizing, precipitating and recovering other valuable metals through crystallization mother liquor; sulfur, sulfur concentrate slag and gold and silver slag are separated from oxygen pressure leaching slag through conventional flotation, the sulfur concentrate slag is returned to the pyrogenic smelting process, and gold and silver products can be obtained by dissolving the gold and silver slag through aqua regia and selective reduction.

The invention relates to the technical field of isotope solution storage, in particular to an antimony isotope standard solution and a preparation method and application thereof.The method comprises the steps that antimony isotope particles are dissolved in a mixed solution of reverse aqua regia and hydrofluoric acid and dried, and an antimony isotope solid matter is obtained; reverse aqua regia and hydrofluoric acid are ingeniously selected as a dissolving system, Sb < 3 + > is complexed by hydrofluoric acid to form [SbF6] < 3->, the problem of isotope ratio drift caused by Sb < 3 + > hydrolysis is effectively inhibited, the strong oxidizing property of the reverse aqua regia ensures that Sb is completely converted into Sb < 5 + >, and the content of the Sb < 5 + > is increased. Therefore, valence fluctuation is avoided, long-term stable preservation of the antimony isotope standard solution is achieved, and the problems that an existing antimony isotope standard solution is prone to hydrolysis and unstable in valence are effectively solved.

The present application relates to a method for determining high content copper, lead and zinc in polymetallic ore and copper-lead-zinc alloy by ICP-AES, and belongs to the technical field of ICP-AES analysis and testing, and the specific steps are as follows: the polymetallic ore and copper-lead-zinc alloy sample is decomposed into wet salt by aqua regia; then hydrochloric acid-ammonium acetate mixed extraction liquid is added, and the mixture is heated to micro-boiling for 10-15 min; the extracted sample is diluted with deionized water in a 250 mL volumetric flask; the diluted sample is shaken and left to clarify; 5 mL of supernatant solution is taken out with a 10 mL large-volume pipette and placed in a 50 mL colorimetric tube, 5 mL of hydrochloric acid-ammonium acetate mixed extraction liquid is added, and the mixture is diluted and shaken; the obtained sample is subjected to ICP-AES testing to determine the content of copper, lead and zinc. The present application avoids complicated operation, solves the problem of serious low test results caused by mutual influence of lead, copper and zinc during testing, and can improve the testing accuracy of high content copper, lead and zinc in polymetallic ore and copper-lead-zinc alloy.

The invention relates to the technical field of high-purity noble metal catalysts, in particular to a preparation method of high-purity iridium powder, which comprises the following steps: iridium dissolution and liquid preparation: adding chloroiridic acid into deionized water, stirring and dissolving, and filtering to remove insoluble substances to obtain an iridium solution A; complexing and precipitating iridium: adding didecyl dimethyl ammonium chloride into the iridium solution A, heating to 80-90 DEG C, separating out a large amount of yellow precipitate, and filtering when the solution becomes colorless from orange red to obtain iridium-containing precipitate B; recrystallization: adding the iridium-containing precipitate B into deionized water for recrystallization, and filtering to obtain an iridium-containing precipitate C; dissolving the iridium-containing precipitate C to prepare a solution, namely adding the iridium-containing precipitate C into dilute ammonia water with the pH value of 8-9 to be dissolved to obtain an iridium solution D, and filtering to remove trace insoluble impurities; and reducing to obtain high-purity iridium powder: adding hydrazine hydrate into the iridium solution D under a micro-boiling condition for reaction, filtering after reduction to obtain iridium powder, boiling and washing with aqua regia, filtering, washing with deionized water, and drying in vacuum to obtain the high-purity iridium powder.

The application belongs to the technical field of wet assay, and provides a multi-module cooperative wet assay acid-dissolution automation device and method. The wet assay acid-dissolution automation device integrates a positive aqua regia real-time preparation pump group, a negative aqua regia real-time preparation pump group, a drop horizontal movement module and a cover opening module. The aqua regia real-time preparation, automatic cover opening, quantitative liquid addition and dynamic shaking are integrated in a single device, thereby solving the process fragmentation and cooperation failure caused by the traditional manual + multiple single machine mode.

This invention discloses a method for recovering gold from gold-containing materials using ultrasound-assisted persulfate extraction, belonging to the field of hydrometallurgical technology. The method involves mixing finely ground gold-containing materials, an acetonitrile aqueous solution, and persulfate, followed by ultrasound-enhanced leaching in an alkaline environment. After leaching, solid-liquid separation is performed to obtain a leachate and a leaching residue. The leachate is then evaporated and crystallized to achieve solvent recovery and reuse, as well as separation of the gold-containing solids. The gold-containing solids are then reduced and calcined to obtain elemental gold. Compared to traditional cyanide and aqua regia leaching processes, this invention eliminates the need for toxic substances and catalysts, significantly improving the selective extraction efficiency of precious metals through ultrasound enhancement. Simultaneously, the solvent can be recycled, reducing costs and avoiding excessive waste residue. This method is green, safe, and highly efficient, possessing significant potential for industrial applications.

The invention discloses a sponge platinum preparation method and sponge platinum prepared by the same, belongs to the technical field of precious metal material preparation, and aims to solve the problems that existing sponge platinum is insufficient in purity, poor in morphology and granularity controllability, low in efficiency and insufficient in thermal stability, the purity of a raw material chloroplatinic acid is difficult to control, and safety and environmental protection are poor. The chloroplatinic acid is prepared by dissolving platinum powder and aqua regia at the temperature of 80-90 DEG C, evaporating and concentrating, refrigerating and crystallizing, and drying at the low temperature of 40-60 DEG C; the preparation method comprises the following steps: by taking chloroplatinic acid as a raw material, preparing a solution, stirring at 60-80 DEG C at 200-250r / min, adjusting the pH to 8-10 at a sodium hydroxide dropping rate of 1-3mL / min, adding formaldehyde to carry out reduction reaction, carrying out centrifugal separation at 1000-2000r / min, washing until no chloride ions exist, and drying at 100-120 DEG C for 0.5-1h to obtain the sponge platinum. Full-process parameters are optimized, the total impurity content of the prepared sponge platinum is smaller than or equal to 0.0005%, the sponge platinum is in a uniform porous spherical shape, the average particle size is 1-5 microns, the mass loss at the high temperature of 400 DEG C is smaller than or equal to 0.1%, the total reaction time is smaller than or equal to 2 h, the platinum recovery rate is larger than or equal to 99.5%, and the sponge platinum is safe and environmentally friendly and can meet the requirements of the fields of high-end electrons, precise catalysis and the like.

The invention relates to a method for determining the platinum content in platinum-tungsten alloy slag. The invention aims to solve the problems of incomplete digestion, platinum loss, matrix interference and the like when the high-tungsten low-platinum alloy slag is treated by the existing wet digestion technology. The method is based on a fire assaying enrichment principle, and comprises the following steps: mixing and melting a sample, lead powder and pure gold with known mass, carrying out soot blowing to obtain platinum alloy particles, dissolving the platinum alloy particles through aqua regia, determining the total amount of impurities in combination with ICP (Inductively Coupled Plasma) spectrum, and finally calculating the platinum content according to Pt (%) = (W2-W1-W3) / W0 * 100%. According to the method, efficient separation of platinum and tungsten is effectively achieved, the determination accuracy and reproducibility are remarkably improved, and the method is suitable for rapid, safe and high-precision analysis of various platinum-tungsten alloy slag.

The invention relates to the technical field of chemical analysis, in particular to a tungsten carbide / cobalt polymer powder sample dissolving method and a chemical component content determination method.According to the method, a mixed solution of phosphoric acid and sulfuric acid cooperates with aqua regia to serve as a dissolving solution to dissolve a tungsten carbide / cobalt polymer powder sample to be dissolved, and rapid dissolving of tungsten carbide / cobalt polymer powder can be achieved; the reaction time is short and a high-temperature oxidation process is not needed; tungsten, cobalt and iron elements in the tungsten carbide / cobalt polymer powder are measured by combining inductively coupled plasma atomic emission spectrometry, a sample is treated once, the chemical component content of the tungsten carbide / cobalt polymer powder is measured under the same medium and the same condition, multiple sample dissolution and accumulation of detection errors can be effectively avoided, and the detection accuracy is improved. The method has the advantages of low detection limit, high sensitivity, wide linear range, high precision, good stability, less interference and capability of simultaneously determining multiple elements, and solves the problems of long sample dissolving time, long chemical component content determination period and low efficiency of tungsten carbide / cobalt polymer powder.

The application discloses a preparation method of gold powder for thick film conductive paste, and the method comprises the following steps: firstly, dissolving gold blocks in aqua regia, adding ammonium chloride, and evaporating to prepare ammonium chloraurate powder; secondly, mixing the ammonium chloraurate powder with ascorbic acid and ball milling to obtain uniformly mixed gold-containing precursor powder; thirdly, calcining the gold-containing precursor powder at low temperature in air to obtain nanometer gold powder; and fourthly, adding the nanometer gold powder into anhydrous ethanol to prepare nanometer gold suspension, and then performing high-temperature atomization to obtain spherical gold powder. By controlling the ball milling time of the ammonium chloraurate and ascorbic acid, combining with the control of low-temperature calcination parameters and the temperature of high-temperature atomization, the gold powder for thick film conductive paste is finally obtained, the addition and cleaning of a direct liquid-phase reduction gold powder dispersant are avoided, the spherical morphology and high purity of the gold powder are ensured, the gold powder is suitable for thick film conductive use, the preparation method is simple in process, high in product yield, large in output, green in environment protection, and easy for industrial production.

The application discloses a method for selectively recovering platinum from waste nickel-platinum target material, and belongs to the technical field of precious metal separation. In the method, different physical forms of the waste nickel-platinum target material are treated by using appropriate pretreatment methods. For planing materials, an acidic dissolving agent is used to selectively dissolve nickel; for block or ingot materials, aqua regia is used to completely dissolve and then reduce and enrich platinum. The platinum-containing material obtained through pretreatment is dissolved by using aqua regia, the pH of the solution is adjusted to 0.2-0.9, a reducing agent is added to perform a reduction reaction, platinum is selectively precipitated as platinum black, and then sponge platinum with a purity of greater than or equal to 99.95% is obtained through calcination. The method realizes targeted treatment of different forms of waste materials, and through accurate pH adjustment and the synergistic effect of a specific reducing agent, efficient and selective reduction of platinum is realized, the residual platinum in the filtrate is less than 0.5 ppm, secondary recovery is not needed, the process is short, safety is high, the product purity is high, and the method is suitable for industrial production.

The application relates to a process flow for extracting uranium, tungsten, tin, copper, iridium, gold and silver from waste uranium ore, which comprises the following steps: waste ore dressing: crushing the waste uranium ore, sequentially performing electroseparation-primary separation-dressing to obtain dressing ore, mixing the dressing ore with concentrated sulfuric acid and sintering, and then using concentrated sulfuric acid for leaching again to obtain first leaching liquid and first leaching residue. Leaching liquid treatment: sequentially electrolyzing and replacing silver and copper from the first leaching liquid, adding ammonia water and caustic soda, and then separating and filtering to obtain uranium compound precipitate. Leaching residue treatment: separating weak magnetic metal and strong magnetic metal from the first leaching residue through electromagnetic separation, adding aqua regia to the weak magnetic metal to leach gold, obtaining fourth leaching liquid and second leaching residue, and reducing the fourth leaching liquid to obtain gold powder; mixing the strong magnetic metal with alkali and sintering, adding pure alkali and water after grinding to obtain fifth leaching liquid and third leaching residue. Through the above method, the dressing ore with a higher grade is screened from the low-grade waste uranium ore, and then silver, copper, uranium, gold, tin, tungsten and iridium are sequentially separated.

The application discloses a method for recovering gold from waste circuit boards, comprising the following steps: washing the waste circuit boards, adding a first acid liquor and a first oxidizing agent, and performing oxidation pretreatment; adding a second acid liquor, a gold dissolving agent and a second oxidizing agent to the waste circuit boards after the oxidation pretreatment, performing leaching, and performing solid-liquid separation to obtain a gold-containing liquid; adding a displacement agent to the gold-containing liquid to completely displace gold in the gold-containing liquid, and performing filtration to obtain filter cake A; dissolving the filter cake A with aqua regia, adjusting the pH of the solution after removing nitrate with sodium hydroxide, and obtaining solution A; adding a reducing agent to the solution A until no more precipitate is generated, and performing filtration to obtain filter cake B; adding dilute nitric acid to the filter cake B, performing heating and boiling, then performing solid-liquid separation, and obtaining filter cake C; washing the filter cake C with deionized water until neutral, and drying to obtain sponge gold.

This invention relates to the field of platinum nitrate preparation technology, and more particularly to a method for preparing high-purity platinum nitrate. The method comprises the following steps: Step A, adding aqua regia to platinum powder to completely dissolve the powder and prepare a chloroplatinic acid solution; Step B, adding excess sodium hydroxide under stirring and heating to prepare a sodium hydroxyplatinate mixture; Step C, titrating the sodium hydroxyplatinate mixture with nitric acid under stirring in an ice-water bath, maintaining the temperature below 50°C during titration. This method for preparing high-purity platinum nitrate is characterized by its simplicity, absence of complex reactions, and the resulting platinum nitrate being chloride-free, highly pure, and having a high yield and preparation efficiency. It solves the technical problems of existing platinum precursor chloroplatinic acid containing a large amount of chloride ions, which easily affects catalytic effects, and the low preparation efficiency of existing platinum nitrate preparation methods.

This invention discloses a method for high-efficiency ultrasonic recovery of gold from gold-containing materials, belonging to the field of hydrometallurgical technology. The method involves mixing finely ground gold-containing materials, an acetonitrile aqueous solution, and a catalyst, followed by ultrasonic leaching in an alkaline environment. After leaching, solid-liquid separation is performed, yielding a leachate and a catalyst-containing leaching residue. The leachate is then evaporated and crystallized to achieve solvent recovery and reuse, and separation of the gold-containing solid material. The gold-containing solid material is then reduced and calcined to obtain elemental gold. Compared to traditional cyanide and aqua regia leaching processes, this invention eliminates the need for toxic substances and significantly improves the selective extraction efficiency of precious metals through ultrasonic enhancement. Furthermore, both the solvent and catalyst can be recycled, reducing costs and avoiding excessive waste. This method is green, safe, and highly efficient, possessing significant potential for industrial applications.

The present invention aims to provide a method for manufacturing (regenerating) an adsorbent material or recovering a target substance by performing a desorption treatment on the target substance after adsorbing it onto the adsorbent material. This method enables the removal of a sufficient amount of the target substance without the use of aqua regia during the desorption treatment and prevents a decrease in the adsorption performance of the adsorbent material after the desorption treatment. To solve this problem, a method for manufacturing an adsorbent material or recovering a target substance is provided, the method comprising the following steps: step (1), preparing a second adsorbent material obtained by contacting a first adsorbent material with a liquid containing the target substance, wherein the first adsorbent material has a co-continuous structure formed by a ceramic framework containing mesopores and macropores, and the surface of the ceramic framework is modified with functional groups capable of adsorbing the target substance; and step (2), removing the target substance from the second adsorbent material by contacting it with an acidic solution other than aqua regia to obtain a third adsorbent material or the target substance.

The invention provides a method for improving the precipitation rate of platinum in a nickel-platinum solution, which comprises the following steps: adding a ferric chloride solution and ammonium chloride into the nickel-platinum solution, and carrying out an ammonium chloride platinum precipitation reaction to generate an ammonium chloroplatinate precipitate; the nickel-platinum solution is obtained by dissolving nickel-platinum alloy or waste thereof by using aqua regia and then at least carrying out nitrate removal treatment; the volume ratio of the nickel-platinum solution to the ferric chloride solution is 10: (1-1.5). The method is easy to operate and low in energy consumption, the requirements of modern industry for high efficiency, environmental protection and energy saving are met, the ferric chloride solution and ammonium chloride are added into the nickel-platinum solution, under the action of ferric chloride, platinum can be effectively inhibited from entering a liquid phase, the loss of platinum in the precipitation process is greatly reduced, and the precipitation rate and purification efficiency of platinum are remarkably improved.

The invention provides a method for synchronously measuring multiple elements in a geochemical sample based on ICP-OES (Inductively Coupled Plasma-Optical Emission Spectrometer), which comprises the following specific steps: crushing, grinding and drying a sample, and digesting the sample at 280 DEG C by using hydrofluoric acid-nitric acid-perchloric acid (5: 4: 1) mixed acid; subsequently extracting with 1: 1 aqua regia; preparing a standard solution matched with the acidity of the sample, synchronously measuring the spectral intensity of constant and characteristic elements by utilizing ICP-OES, and quantitatively calculating the element concentration through a standard curve. According to the method, the sample pretreatment and ICP-OES detection conditions and the sample pretreatment process are optimized, the detection efficiency is remarkably improved, multi-element analysis can be completed through a single test, and efficient multi-element synchronous analysis is achieved.

This invention provides an automated potentiometric titration method for determining the platinum content in platinum jewelry, belonging to the field of precious metal analysis and detection technology. The method mainly includes: dissolving the platinum jewelry sample in aqua regia and using a separating reagent to precipitate and separate interfering precious metals such as palladium, gold, and silver. Subsequently, the sample is passed through a strongly basic anion exchange resin column, where platinum is selectively adsorbed as chloroplatinate complex anions to obtain a purified platinum solution. The platinum content is calculated using a back titration method. This method integrates interfering element separation, ion exchange purification, back titration, and automated potentiometric detection technologies, and optimizes the electrode system. This method has the advantages of high accuracy, good precision, strong anti-interference ability, and relatively simple and reliable operation, and is suitable for the accurate determination of platinum content in platinum jewelry and platinum alloys of various purities such as Pt900, Pt950, and Pt990.

The application discloses a kind of determination methods of the platinum content in automobile electric pile, the method is dissolved in aqua regia medium to automobile electric pile using microwave digestion instrument, ensure that the platinum in electric pile can be completely dissolved, after dissolving the sample to be measured is transferred into 100mL volumetric flask, with water constant volume, on inductively coupled plasma emission spectrometer to determine the platinum content, obtain the test result.Compared with the original ashing decomposition activated carbon sample pretreatment process, the application has sample complete dissolution, simple analysis process.Compared with the determination of platinum content by spectrophotometry, the application has high determination sensitivity, fast determination speed, small interference, wide linear range, and can realize multi-element joint measurement and other characteristics.The application can extend the determination of platinum content in carbon material.

The application discloses a high-purity gold refining process in the technical field of gold refining, which comprises the following steps: after gold raw materials are made into pieces, the gold is dissolved in a hydrochloric acid-sodium chlorate system in steps and then is dissolved in aqua regia for strengthened final solution, gold-containing solutions are combined, a magnetic multi-tooth coordination inorganic modified material is added for deep adsorption of impurities, a purified chloroauric acid solution is obtained through separation under an applied magnetic field, high-purity gold is prepared through reduction precipitation, acid boiling and impurity removal and smelting in an inert atmosphere. The magnetic multi-tooth coordination inorganic modified material is prepared by using ferroferric oxide as a magnetic core, coating a silica layer and a porous zinc-aluminum layered double metal oxide shell layer in sequence, and then performing surface modification through amination, and is prepared through covalent grafting of ethylenediaminetetraacetic dianhydride and nitrilotriacetic acid and coordination anchoring. Through the cooperation of step-by-step gold dissolution and magnetic multi-tooth coordination adsorption, the gold dissolution rate and deep removal of impurities are effectively considered, the operation is simple, the adsorption material can be separated and recycled under an applied magnetic field, and the product has high purity.

This invention provides a method for recovering Pt and Ir from waste water electrolysis membrane electrodes, comprising the following steps: Step S1. Dissolving and separating platinum and iridium: The waste water electrolysis membrane electrode is soaked in an organic solvent and separated to obtain a catalyst mixture residue. The catalyst mixture residue is added to a first reagent and calcined at high temperature to obtain precious metal residue. The precious metal residue is dissolved in hydrochloric acid and filtered to obtain a mixed residue. Then, the mixed residue is dissolved in a solvent and filtered to obtain chloroplatinic acid and iridium residue. The chloroplatinic acid is then reduced and purified to obtain platinum compound or platinum black. Step S2. Separating iridium: The iridium residue is added to a second reagent to oxidize and dissolve the iridium residue into chloroiridium acid and insoluble residue. The chloroiridium acid is oxidized with an oxidant, and then ammonium chloride is added and stirred to precipitate it to obtain ammonium chloroiridate. After purification, iridium compound or iridium black is prepared, and the insoluble residue is dissolved in aqua regia for reuse. This invention adds hydroxide to the precious metal residue during calcination, minimizing mechanical entrainment loss and preventing melt splashing during oxidative calcination.