393 results about "Cadmium" patented technology

The invention discloses a high-weather-resistance bismuth vanadate coating and a preparation method thereof, and belongs to the technical field of inorganic pigment modification. The high-weather-resistance bismuth vanadate coating comprises bismuth vanadate matrix particles, and the surfaces of the bismuth vanadate matrix particles are sequentially coated with an amorphous aluminum oxide layer, a cerium oxide layer and a fluorinated silicon oxide layer. The amorphous aluminum oxide layer is formed in an atomic layer deposition mode; the cerium oxide layer is formed by hydrothermal treatment of a cerium source. The preparation technology has accurate and controllable technological parameters, is suitable for industrial production, can replace the traditional toxic pigment containing lead and cadmium, and meets the requirements of environmental regulations. The bismuth vanadate coating has excellent weather resistance and chemical stability, the service life of a product can be prolonged, the maintenance cost is reduced, and a reliable solution is provided for development of high-performance environment-friendly pigments.

The invention relates to the technical field of agriculture, in particular to a preparation method and an application method of a zinc-rich cadmium-reducing yield-increasing foliar fertilizer. The specific technical scheme is as follows: the zinc-rich cadmium-reducing yield-increasing foliar fertilizer is prepared from the following components in percentage by mass: 20 to 30 percent of porous chitosan, 30 to 40 percent of L-malic acid and 40 to 50 percent of nano zinc oxide. The technical problem that in the prior art, the zinc content of rice cannot be increased, meanwhile, the rice yield cannot be increased, and the cadmium content of rice cannot be reduced is solved.

The invention discloses a sodium alginate embedded iron-carbon microcapsule material for repairing cadmium and arsenic polluted soil and a preparation method of the sodium alginate embedded iron-carbon microcapsule material, and belongs to the technical field of soil heavy metal pollution repairing materials. The material comprises straw biochar, high-iron steel slag powder, a sulfydryl acetylated chitosan-iron monatomic cluster compound, a boron-doped graphitized carbon coated cobalt ferrite nanosheet, sodium alginate, calcium chloride and sodium carbonate. Wherein the sulfydryl acetylated chitosan is prepared by reacting chitosan with sulfydryl acetic anhydride, dialyzing and drying, and performing solvothermal reaction with ferric nitrate under high pressure. The preparation method comprises the following steps: pyrolyzing and drying the straw biochar, reacting the high-iron steel slag with sulfuric acid, adding the biochar, adjusting the pH value, adding sodium carbonate, mixing to obtain an iron-carbon-based passivation material, mixing with two modified compounds, mixing with a sodium alginate solution, dropwise adding a calcium chloride solution, and stirring and curing. The material can be applied to remediation of cadmium and arsenic polluted soil.

The invention discloses a double-vacancy ZnCdS solid solution photocatalyst and a preparation method and application thereof.The preparation method comprises the steps that a cadmium source, a zinc source and a sulfur source are added into absolute ethyl alcohol to be stirred and dissolved, the mass ratio of the cadmium source to the zinc source to the sulfur source is 1: 9: 3, a reaction is conducted under the water bath condition of 70-90 DEG C, suction filtration, washing and drying are conducted, and a powdery ZnCdS solid solution is obtained; the preparation method comprises the following steps: adding NaOH into water, stirring and dissolving, then adding the powdery ZnCdS solid solution, carrying out ultrasonic treatment, and carrying out suction filtration, washing and drying to obtain the double-vacancy ZnCdS solid solution photocatalyst. The preparation method has the advantages of being high in hydrogen production rate, good in repeatability and stability, simple and convenient to prepare, low in cost and the like, the obtained double-vacancy ZnCdS solid solution photocatalyst can be applied to the field of photocatalytic hydrogen production, and the hydrogen production efficiency reaches up to 12.69 mmol.g <-1 >. H <-1 > and is 23.94 times that of pure ZnS and 11.64 times that of pure CdS.

The invention relates to the technical field of biomass-based semiconductor bifunctional materials and environmental restoration, in particular to a Baijiu vinasse biochar / cerium oxide / cadmium zinc sulfur solid solution heterojunction bifunctional material as well as a preparation method and application of the Baijiu vinasse biochar / cerium oxide / cadmium zinc sulfur solid solution heterojunction bifunctional material. The method comprises the following steps: in an inert atmosphere, carrying out pyrolysis on waste Baijiu vinasse to obtain biochar; the method comprises the following steps: mixing biochar and an activator, and carrying out activation pyrolysis in an inert atmosphere to obtain alkali-activated biochar; the preparation method comprises the following steps: dispersing a cadmium source, a zinc source, thiourea, a surfactant, alkali-activated charcoal and cerium dioxide in a solvent to form a dispersion liquid, and carrying out a heating reaction to obtain the Baijiu vinasse charcoal / cerium oxide / cadmium-zinc-sulfur solid solution heterojunction bifunctional material. The adsorption performance of the material is improved due to the remarkable specific surface area of the alkali-activated biochar component; the construction of the cerium oxide / cadmium zinc sulfur solid solution heterojunction significantly accelerates the migration of photon-generated carriers, endows the material with excellent adsorption-photocatalytic performance, has good reusability, and can remove pesticide pollutants in water.

The invention discloses a preparation method and application of an iron-manganese modified biochar material for remediation of cadmium and arsenic contaminated soil, and relates to the field of new materials.According to the material, rice hull biochar serves as a carrier, and the specific surface area and surface active sites are increased through programmed intermittent ball milling; and the Fe-O / Mn-O bonding modification complex is formed through gradient loading of iron and manganese oxides. The maximum adsorption capacity of the material to Cd < 2 + > and As (V) reaches 71.54 mg.g <-1 > and 49.30 mg.g <-1 > and is 1.65 / 2.53 times that of original biochar, the content of available Cd and As in soil is reduced by 8.98% and 25.2% under the condition that the addition amount is 0.4%, and the passivation efficiency is improved by 1.05 times (Cd) and 9.08 times (As) compared with that of non-ball-milled iron-manganese modified biochar; the material prepared by the method is applied to cadmium and arsenic polluted soil, pollution can be controlled by waste, and the soil can be effectively repaired.

The invention relates to the technical field of metal purification, and discloses a two-stage rectification purification method of high-purity superfine zinc powder, which comprises the following steps: first-stage rectification is performed on a crude zinc raw material, and a collaborative purification control process is adopted in the first-stage rectification to remove low-boiling-point impurities, so that preliminarily purified zinc liquid is obtained; the collaborative purification control process comprises the steps that first state data of a first rectifying tower are obtained in real time, the future state of the first rectifying tower is predicted based on a first dynamic model, a first optimal control instruction is obtained through online optimization calculation according to a prediction result, and the first optimal control instruction is executed. According to the method, the process tomography technology and the self-calibration dynamic digital twinborn model are combined, real-time and accurate sensing and prediction of the internal fluid dynamic state in the rectification process are achieved, the operation stability of the whole rectification process is remarkably improved, and meanwhile effective separation of cadmium and lead can be achieved.

The invention relates to the cross technical field of industrial solid waste resource utilization and environmental pollution abatement, and discloses a modified fly ash environmental remediation material as well as a preparation method and application thereof. According to the material, industrial solid waste fly ash is used as a raw material, a glass body structure is destroyed through physical or chemical modification treatment, the specific surface area is increased, active functional groups such as surface hydroxyl groups are enriched, and the adsorption and fixation capacity on heavy metal lead (Pb < 2 + >) and cadmium (Cd < 2 + >) is remarkably improved. The chemical modification adopts an acid solution or an alkali solution, and the preparation method comprises the steps of raw material pretreatment, modification reaction, solid-liquid separation and washing, and drying and screening. When the material is applied to heavy metal contaminated soil remediation, heavy metal in an ion exchange state is promoted to be converted into a stable residue state, the bioavailability and the leaching risk of the heavy metal are remarkably reduced, meanwhile, high-added-value resource utilization of the fly ash is achieved, and the material has environmental, economic and social benefits and is suitable for large-scale remediation of Pb and Cd single or combined contaminated soil.

The invention relates to the technical field of gas analysis, in particular to a determination method for detecting impurity elements in chlorine-nitrogen mixed gas by an ICP-MS (Inductively Coupled Plasma Mass Spectrometry) method. The invention establishes an analysis method for determining the contents of eight elements including iron (Fe), chromium (Cr), copper (Cu), zinc (Zn), nickel (Ni), sodium (Na), cadmium (Cd) and phosphorus (P) in chlorine-nitrogen mixed gas by an ICP-MS (Inductively Coupled Plasma Mass Spectrometry) method. By optimizing ICP-MS analysis conditions and a sample pretreatment process and adopting an electronic-grade solvent to leach elements, rapid and accurate detection and high reproducibility of the impurity content in the chlorine-nitrogen mixed gas are realized. The method can be applied to quality control and analysis in the production process of a chlorine-nitrogen mixed gas product, and lays a foundation for establishing a standard of a chlorine-nitrogen mixed gas analysis method.

The invention discloses an iron-carbon composite material for heavy metal contaminated soil remediation and a preparation method of the iron-carbon composite material, and belongs to the field of heavy metal contaminated soil remediation. The iron-carbon composite material comprises rape straw, hydroxyapatite, zero-valent iron, sulfydryl functionalized magnetic cerium oxide and nitrogen-doped graphene quantum dot-sodium alginate. The sulfydryl-functionalized magnetic cerium oxide is prepared from cerium nitrate and ferric nitrate through precipitation, calcination and sulfhydrylation, and the nitrogen-doped graphene quantum dot-sodium alginate is prepared from citric acid and urea through microwave reaction, dialysis, mixing and freeze drying; the preparation method comprises the following steps: treating straws and hydroxyapatite to obtain ball-milled phosphorus-containing biochar, mixing the ball-milled phosphorus-containing biochar with zero-valent iron and two modifiers, and carrying out molding and high-temperature calcination to obtain the phosphorus-containing biochar-based composite material. The material has a remarkable remediation effect on the heavy metal contaminated soil, can effectively reduce the activity of heavy metals in the soil, has the characteristics of environmental friendliness and high stability, and is suitable for treating the soil compositely contaminated by the heavy metals such as cadmium and lead.

The invention relates to the technical field of agriculture, in particular to a zinc-rich cadmium-reducing leaf surface blocking and controlling agent as well as a preparation method and an application method thereof. According to the specific technical scheme, the zinc-rich cadmium-reducing leaf surface blocking and controlling agent is prepared from, by mass, 10%-20% of gamma-chitosan, 20%-30% of L-malic acid and 50%-70% of zinc sulfate. The technical problem that in the prior art, the cadmium content of brown rice cannot be reduced through a leaf surface blocking and controlling agent is solved.

The invention belongs to the field of wastewater treatment, and particularly relates to a selective separation method for zinc and cadmium in a low-concentration-difference difficult-to-separate zinc-cadmium-containing solution, which comprises the following steps: carrying out co-precipitation reaction on the low-concentration-difference difficult-to-separate zinc-cadmium-containing solution and an alkaline precipitator to obtain co-precipitation slag enriched with zinc and cadmium; the low-concentration-difference difficult-to-separate zinc-cadmium-containing solution is a solution in which the ratio of the concentration of high-concentration ions to the concentration of low-concentration ions in zinc and cadmium is 0.9-2; the concentration of cadmium is 8-40g / L; the coprecipitation slag is subjected to size mixing with water, selective cadmium dissolving is carried out under the condition that the pH of size obtained after size mixing is controlled to be 6-7.1, then solid-liquid separation is carried out, and zinc-rich slag and cadmium-rich leachate are obtained; the solid-to-liquid ratio in the slurry is 85-150g / L; carrying out deep zinc removal treatment on the cadmium-rich leachate to obtain a cadmium purification solution, and preparing the cadmium purification solution into a high-purity cadmium product with the grade of 3N or above; and the zinc-rich slag is subjected to acid leaching and deep cadmium removal treatment, a zinc purification solution is obtained, and then the zinc purification solution is prepared into a 2N-grade high-purity zinc product. According to the method disclosed by the invention, high-quality cadmium and zinc can be obtained at high yield.

The invention belongs to the technical field of water environment detection, and particularly relates to a heavy metal concentration and water body flow velocity synchronous detection method for a dispersed drain outlet, which is used for synchronously detecting the heavy metal cadmium concentration and the water body flow velocity. The core of the method comprises a three-electrode sensing system consisting of a working electrode coated with a tungsten oxide film, a reference electrode and a counter electrode, and is assisted by an electrochemical workstation, a peristaltic pump, a flow cell and a signal processing module. The cadmium concentration is accurately measured through the square wave anodic stripping voltammetry, the flow velocity is synchronously detected through the open circuit potentiometry, dual-function detection is achieved through integration of the square wave anodic stripping voltammetry and the open circuit potentiometry, synchronous in-situ detection of the cadmium concentration and the water body flow velocity is achieved, and errors caused by measurement position differences are effectively eliminated. The result shows that the cadmium concentration and the dissolution peak current are in a linear relationship, and the water flow velocity logarithm and the open-circuit potential are in a linear relationship. The method designed by the invention is suitable for scattered and small sewage draining exit scenes, and effectively solves the problems of time consumption and equipment redundancy of traditional step-by-step detection. In an actual water sample test, the cadmium recovery rate is 80%-120%, the flow velocity measurement RSD is smaller than or equal to 5.0%, high reproducibility, stability and anti-interference performance are achieved, technical support is provided for real-time online evaluation of the total heavy metal emission amount, and the method has remarkable environmental monitoring application potential.

The utility model discloses a bottom solution residue prevention sample holder for vertical tellurium-cadmium-mercury liquid-phase epitaxial growth, which belongs to the field of infrared semiconductor material preparation and comprises a conical flow guide base, a micro-groove array, a SiC / SiO2 super-lyophobic functional layer and a thermal gradient regulation and control module. During working, the frame body is preheated, the melt flows back along the chamfer surface under the action of gravity during lifting, the micro-grooves generate capillary force for directional diversion, the super-lyophobic layer reduces the adhesion work, and the thermal gradient inhibits solution solidification. By applying the sample holder, the residual quantity of a melt can be greatly reduced, the defect density of an epitaxial layer is reduced, the available area is increased to more than 95%, and the problem of millimeter-scale particle residue in the traditional LPE growth is solved.

The present disclosure provides a Group II-VI core-shell quantum dot and a preparation method therefor. A quantum dot shell having a gradient alloy structure is gradually grown by using a precursor that has a reactivity gradient. The gradient alloy structure has a band gap that gradually increases from inside to outside, thereby solving the problem of difficulty in epitaxial growth caused by a decrease in the surface activity of a quantum dot along with an increase in the size thereof. By using zinc halide and octanethiol to regulate crystal facets, the proportion of polar facets on the surface of the quantum dot is increased, and the stability of the quantum dot is significantly improved. Moreover, provided is a low-cadmium quantum dot core. A hot-injection method is used to perform nucleation and growth of ZnSe at a high temperature, a cadmium precursor is then added after the stable nucleation of ZnSe, and cadmium / zinc ion exchange is performed by utilizing the binding energy of selenium / cadmium that is stronger than that of selenium / zinc, thereby forming a CdZnSe ternary core, which can solve the problem of it being difficult for blue-light quantum dots that use CdZnSe as a light-emitting core to cover the pure blue band.

The invention belongs to the technical field of medicine detection, and particularly relates to an ICPMS (Inductively Coupled Plasma Mass Spectrometry) detection method for element impurities in theophylline. The linear test solution, the blank solution and the theophylline test solution are subjected to ICPMS detection, the content of element impurities in the theophylline test solution is calculated according to an internal standard curve method, and the element impurities are one or more of cadmium, lead, arsenic, mercury, cobalt, vanadium, nickel, lithium, antimony or copper. The method is good in reproducibility and stability, high in accuracy and high in precision.

The invention relates to the technical field of soil remediation, in particular to an iron-modified cow dung biochar material and a preparation method thereof and application in remediation of cadmium-copper contaminated soil. Cow dung is used as a raw material, pretreated cow dung is obtained through natural airing, dewatering and smashing, then the pretreated cow dung and a ferrous chloride solution are mixed, stirred, filtered, dried and ground, and the iron-modified cow dung biochar material is obtained. And pyrolyzing under the protection of inert gas. The iron-modified biochar has a porous layered structure, rich oxygen-containing functional groups and iron-based active sites, has a pH value close to neutrality, and can effectively adapt to the farmland soil environment. The material can remarkably reduce the effective state content of cadmium and copper in soil, promote conversion of heavy metal to a stable residue state, reduce migration of heavy metal in pore water and improve the enzyme activity and nutrient effectiveness of the soil at the same time, the grain cadmium accumulation reduction amplitude reaches 71.65% and the copper accumulation reduction amplitude reaches 29.36% in the rice growth process, and therefore the cadmium and copper combined polluted soil is efficiently repaired, and the quality of the rice is improved. And crop safety and soil health are guaranteed.

This disclosure relates to a process for removing cadmium and copper, and optionally arsenic, from phosphoric acid solutions typically obtained by wet methods. The process can also allow for the selective and separate recovery of cadmium, copper, and arsenic.

The invention discloses a method and a system for synergistically strengthening a zinc hydrometallurgy purification process based on an activation reactor and an activating agent. The method comprises the following steps: (1) preparing zinc powder slurry; (2) primary copper and cadmium removal; (3) primary secondary removal of copper and cadmium; (4) activating first-stage zinc-copper-cadmium-rich slag; (5) recycling the first-section activated slurry; (6) secondary cobalt and nickel removal; (7) carrying out third-stage deep purification; and (8) activating the third-stage zinc-rich purified slag. According to the method, the unit consumption of the zinc powder can be remarkably reduced, the adding amount of the zinc powder is greatly reduced through efficient activation and cyclic utilization of active zinc carried in the purification slag of each section, it is predicted that the total zinc powder consumption can be reduced by 20%-35%, and the economic benefits are remarkable; and meanwhile, the resource utilization rate is increased, waste residues in a traditional process are converted into resources, systematic internal circulation of zinc resources is achieved, and metal loss is reduced.

The application relates to the technical field of photovoltaic cells and discloses a tellurium cadmium selenide film near-space sublimation deposition method and equipment, wherein the tellurium cadmium selenide film near-space sublimation deposition method comprises the following steps: a cadmium selenide heating chamber is used to heat cadmium selenide raw materials, a first gaseous reaction precursor is obtained, the heating temperature is T1, a cadmium telluride heating chamber is used to heat cadmium telluride raw materials, a second gaseous reaction precursor is obtained, the heating temperature is T2, T1>T2 is met, the first gaseous reaction precursor is introduced into a mixing chamber through a first gas outlet pipe, the second gaseous reaction precursor is introduced into the mixing chamber through a second gas outlet pipe, mixed gas is obtained in the mixing chamber, the mixed gas is transported to a nozzle through a connecting pipe, and the nozzle is sprayed towards a substrate, so that a tellurium cadmium selenide film is formed on the surface of the substrate. The cadmium selenide and the cadmium telluride binary alloy are used for near-space sublimation deposition, the stability of the tellurium cadmium selenide film can be remarkably improved, and the photoelectric conversion efficiency of the cell is improved.

A spectroscopic method of estimating the cadmium concentration in an aqueous sample including: preparing at least 5 aqueous calibration samples, each calibration sample including water, a pH regulator in an amount such that each calibration sample has a pH of from 8 to 10, an equal concentration of dimethylglyoxime and dissolved cadmium in an amount of from 0 to 12 μg / mL; and, measuring over optical path length (l) the absorbance for each calibration sample of radiation (R) having a wavelength of from 520 to 540 nm, thereby generating calibration data. The method further includes: forming a treated aqueous sample; measuring over the optical path length (l) the absorbance for the treated aqueous sample of radiation (R) having a wavelength of from 520 to 540 nm; generating test data; and, estimating the concentration of cadmium in the aqueous sample from the test data and the calibration data.

This invention relates to a method for locating characteristic defects in cadmium zinc telluride (CZT) samples and a method for preparing CZT samples. The location method includes the following steps: determining the positions of internal feature points on the sample under an infrared transmission microscope; establishing marking features on the sample surface using FIB-SEM; and determining the relative position of the internal feature points projected onto the sample surface by establishing a geometric relationship between the virtual position of the internal feature points projected onto the sample surface and the marking features. The preparation method uses these relative positions to prepare CZT samples. The location method of this invention can simply and effectively establish the positional relationship between internal feature points and surface features, accurately locating internal defect features in CZT samples. This allows for convenient and rapid determination of the specific location for preparing transmission electron microscopy (TEM) samples, thus improving the quality of TEM samples.

The invention provides a process for comprehensively recovering copper, cadmium and cobalt from zinc smelting purification slag, the process for comprehensively recovering copper, cadmium and cobalt from zinc smelting purification slag comprises the steps of pretreatment, copper extraction, cobalt extraction and cadmium replacement, efficient separation and recovery of copper, cadmium and cobalt in the purification slag are achieved, and the metal recovery rate is larger than or equal to 95%; high-grade copper slag (Cu > = 80%), cobalt slag (Co > = 30%) and cadmium slag (Cd > = 90%) are produced and can be directly sold as smelting raw materials; the method is simple in process, conventional in reagent, mild in operation condition and suitable for industrial application; and waste liquid can be recycled, environmental pollution is reduced, and the green metallurgy concept is met.

This invention discloses a mercury cadmium telluride infrared detector and its fabrication method. The method innovatively employs negative photoresist and a lift-off process to grow a metal mask and define contact hole patterns. This metal mask layer serves as both an ion implantation mask and a contact hole etching mask, solving the problems of implantation region positioning deviation and size mismatch in traditional processes. It enables ultra-small cell spacing, improves the detector's photoelectric performance and array uniformity, and is suitable for the large-scale fabrication of high-density infrared detector planar arrays.

The application discloses a kind of hollow microspheres of titanium dioxide / cadmium zinc sulfide heterojunction with zinc, oxygen double vacancies, the preparation method of the catalyst of the hollow microspheres of titanium dioxide / cadmium zinc sulfide heterojunction and the catalyst application of the hollow microspheres of titanium dioxide / cadmium zinc sulfide heterojunction.The hollow microspheres of titanium dioxide / cadmium zinc sulfide heterojunction with zinc, oxygen double vacancies of the application, the preparation method of the catalyst of the heterojunction hollow microspheres and the preparation method of the application of the double vacancies heterojunction hollow microspheres are in situ preparation method using one-step hydrothermal method, and double vacancies heterojunction is constructed on the surface of titanium dioxide hollow microspheres, which has the advantages of high activity stability, simple preparation process and controllable reaction conditions.The heterojunction hollow microspheres have wide visible light absorption range, low photo-generated charge recombination rate, and exhibit excellent photocatalytic reduction of carbon dioxide and photocatalytic oxidation of benzyl alcohol activity and good stability.

The application belongs to the technical field of industrial flue gas purification treatment, and particularly relates to a manganese-cadmium bimetallic denitration catalyst and a preparation method and application thereof. The manganese-cadmium bimetallic denitration catalyst has a pore diameter of 4.4-27 nm, a pore volume of 0.25-0.35 cm 3 / g, and a specific surface area of 75-85 m 2 / g. The number ratio of medium acid and strong acid sites contained in the manganese-cadmium bimetallic denitration catalyst is (7-8):1. The manganese-cadmium bimetallic denitration catalyst has the advantages that the manganese-cadmium bimetallic denitration catalyst utilizes the unique synergistic effect of the moderate difference in electronegativity between manganese and cadmium, realizes one-way transfer of electrons from cadmium to manganese, gives the catalyst a moderate SO2 adsorption energy, avoids sulfation of active sites, the difference in radius between Cd 2+ and Mn 2+ induces the skeleton to produce an expansion and cracking type defect, forms a 4.4-27 nm wide distribution mesoporous structure, reduces deposition of sulfate and ammonium salt, and presents a hierarchical porous structure, which enhances gas transfer in the reaction process and significantly improves the catalytic efficiency.

The invention provides a mercury-cadmium-telluride material, a surface passivation heat treatment method thereof and an infrared detector, the surface passivation heat treatment method of the mercury-cadmium-telluride material comprises the following steps: S1, pretreating the surface of a mercury-cadmium-telluride substrate; s2, depositing and growing a high-component HgCdTe film layer on the surface of the tellurium-cadmium-mercury substrate; s3, depositing and growing a CdTe passive film layer on the surface of the high-component HgCdTe film layer; s4, depositing and growing a ZnS passive film layer on the surface of the CdTe passive film layer; and S5, carrying out passive heat treatment on the tellurium-cadmium-mercury substrate treated in the step S4 under the protection of an inert atmosphere. The three composite passivation film layers are adopted, and the high-component HgCdTe film layer and the HgCdTe substrate material are basically consistent in component, crystal structure and lattice constant, so that the problems that the CdTe film layer preparation process is high in requirement, CdTe / HgCdTe generates stress and dislocation and the like when the traditional CdTe passivation film layer is adopted as the first passivation material layer are solved; the process requirement of preparation of the CdTe passive film layer is reduced, the complexity of a heat treatment process is reduced, and the process window of HgCdTe device processing is widened.

The present invention relates to a method for removing cadmium and copper and optionally arsenic contained in phosphoric acid solutions typically obtained in wet processes. The process also enables selective and separate recovery of cadmium, copper and arsenic.

This invention belongs to the field of analytical chemistry technology, specifically relating to a composite indicator and testing method for determining cadmium content in crude cadmium. The composite indicator comprises xylenol orange, thymol blue, and sodium indigo disulfonate, with a mass ratio of xylenol orange, thymol blue, and sodium indigo disulfonate of 1.0–1.5:0.3–0.6:0.5–1.0. This invention utilizes the ternary compound of xylenol orange, thymol blue, and sodium indigo disulfonate, employing the blue background of sodium indigo disulfonate and the reddish-purple and yellow hues of xylenol orange for optical color adjustment. This transforms the color change at the titration endpoint from the traditional reddish-purple to yellow to a bluedish-purple to yellowish-green, significantly increasing the color difference and creating a clear and sharp color change interface, greatly improving the accuracy and reliability of visual endpoint determination.

This invention relates to the field of high-purity material analysis technology, and discloses a method for simultaneously separating and enriching copper, cadmium, nickel, cobalt, zinc, lead, and barium in lithium carbonate. The steps are as follows: dissolving a lithium carbonate sample in nitric acid to obtain an acidified sample solution; adjusting the acidified sample solution to an alkaline pH range of 9.5-10.5 using an ammonia-ammonium acetate alkaline buffer solution; passing the alkaline solution through a solid-phase extraction column filled with iminodiacetic acid-type chelating resin, where copper, cadmium, nickel, cobalt, zinc, lead, and barium ions are selectively adsorbed onto the resin; and eluting the adsorbed heavy metal ions with acid to achieve separation and enrichment. This invention effectively overcomes the inhibition and interference of the lithium carbonate matrix on the detection of trace heavy metals, and in particular significantly improves the adsorption and recovery rate of elements such as barium. It achieves efficient separation and enrichment of multiple heavy metals in complex matrices, providing a reliable pretreatment solution for high-sensitivity and high-accuracy quality control analysis of lithium carbonate products.