3 results about "Tungstate ion" patented technology

The invention relates to a perovskite quantum dot capable of improving luminous intensity through light driving and a preparation method thereof, the perovskite quantum dot comprises a micro / mesoporous template and perovskite nanocrystals located in pore channels of the micro / mesoporous template, and tungstate ions are loaded in the pore channels of the micro / mesoporous template; under the irradiation of blue light, B-site metal cations in the perovskite nanocrystals react with tungstate ions to form a BWO4 passivation layer. According to the invention, the formation of the BWO4 passivation layer in the micro / mesoporous template is driven by blue light illumination, and the surface defects of the perovskite quantum dots are passivated, so that the luminous efficiency of the perovskite quantum dots is further improved.

This invention discloses a method for recovering tungsten and rhenium from tungsten-rhenium alloy waste, belonging to the field of waste metal recycling technology. The method includes: leaching pretreated tungsten-rhenium alloy waste by heating and stirring with a mixed solution of dilute hydrochloric acid and hydrogen peroxide, converting tungsten and rhenium into tungstate ions and perrhenate ions respectively into the solution; then, rapid acidification by quantitatively adding concentrated hydrochloric acid, causing tungsten to precipitate as crystalline tungstic acid; filtering to obtain a crystalline tungstic acid filter cake and a rhenium-containing filtrate; adsorbing the rhenium-containing filtrate through an anion exchange resin to load perrhenate ions onto the resin; subsequently eluting with an ammonia solution to obtain an ammonium perrhenate solution; evaporating, concentrating, and crystallizing to obtain ammonium perrhenate crystals; simultaneously washing and drying the tungstic acid filter cake to obtain the tungstic acid product. This invention features a simple process flow, thorough tungsten-rhenium separation, high recovery rate, is green and economical, and can obtain high-purity tungsten and rhenium products.

This invention discloses a method for controlling tungsten release from sediments using lanthanum-modified red clay, belonging to the field of sediment pollution control and water remediation technology. The invention uses natural red clay as raw material, reacting it with lanthanum chloride hexahydrate at room temperature to prepare lanthanum-modified red clay. This material is then uniformly applied to the surface of tungsten-contaminated sediments. Through the formation of stable lanthanum tungstate precipitates and inner spherical complexes between lanthanum ions and tungstate ions, the adsorption capacity and fixation efficiency for tungsten are significantly improved, effectively inhibiting the release of tungsten from sediments into overlying water. This invention features a simple preparation process, readily available raw materials, low cost, and environmental friendliness. The resulting stable product remains stable under reducing conditions, providing a long-lasting remediation effect. It can achieve a 56.1% fixation rate of dissolved tungsten in interstitial water of sediments, significantly reducing tungsten release flux and the content of unstable tungsten. This method is suitable for in-situ control and ecological remediation of tungsten-contaminated sediments in lakes, rivers, reservoirs, and other water bodies.