784 results about "Sodium tungstate" patented technology

The invention relates to a method for preparing a tungsten oxide nano-wire and a tungsten oxide nano-wire ammonia-sensitive sensor, belonging to the one dimensional nano oxide material preparation and gas-sensitive technical field. The method comprises the following steps that: sodium tungstate is dissolved in deionized water to prepare a sodium tungstate solution; a hydrochloric acid is dripped slowly to prepare a flaxen micellar solution which is then centrifugally separated; products are uniformly dispersed in a potassium sulfate solution which is then transferred into a reaction kettle for hydrothermal reaction, and then the tungsten oxide nano-wire is prepared; adhesives and frit are added into the tungsten oxide nano-wire, and then the tungsten oxide nano-wire ammonia-sensitive sensor is prepared after element sintering and ageing. The method has simple steps, easily controlled technological parameters during the preparation process, and very low energy consumption during the whole preparation process; the tungsten oxide nano-wire prepared has a large specific surface area and high thermal stability; and the tungsten oxide nano-wire ammonia-sensitive sensor prepared has high sensitivity on low-concentration (between 1 and 100 pars per million) H2, CO and NH3, good repeatability and high stability.

The invention relates to a process for preparing high-purity ammonium paratungstate, which can obtain a non-ferrous metal product, namely the ammonium paratungstate with low impurity content, whereinthe impurity content of the ammonium paratungstate is low and is lower than 70 ppm, and the ammonium paratungstate can be directly used for preparing deep processed products of tungsten, such as tungsten powder with low impurity content and the like. The process comprises the following four process steps: (1) a process step of preparing a sodium tungstate solution by using a tungsten concentrate (Fe, Mn)WO4, white tungsten (CaWO4) or a tungsten middling product as a raw material; (2) a process step of performing ion exchange on the sodium tungstate solution; (3) a process step of performing impurity removal and filtration by using an ammonium tungstate solution; and (4) a process step of performing crystallization, washing, drying and screening. The process for preparing the high-purity ammonium paratungstate optimizes the technological processes, improves the quality of a product, and reduces the preparation cost of the product.

The invention discloses blackening liquid for a chromium-free titanium-zinc panel surface and a using method of the blackening liquid. Raw materials of the blackening liquid comprise a main salt, auxiliary components, a complexing agent, a pH conditioning agent and water, wherein the main salt is one or several of molybdate with the massic volume concentration of 5-40g / L or sodium tungstate with the massic volume concentration of 0.5-10g / L or copper sulfate with the massic volume concentration of 0.5-20g / L or silver nitrate with the massic volume concentration of 5-40g / L; the auxiliary components comprise nickel sulfate with the concentration of 1.0-4g / L, sodium sulfite with the concentration of 0.5-4g / L, sodium thiosulfate with the concentration of 1.0-5g / L, aluminium chloride with the concentration of 2.0-5g / L, zinc chloride with the concentration of 2.0-5g / L and fluoric acid with the concentration of 0-40g / L. A black protective layer of a titanium-zinc panel is obtained by a series of treatment of the titanium-zinc panel workpiece. The black protective layer of the titanium-zinc panel is compact, uniform, pitch-black and glossy and has the characteristics of being low in cost, chromium-free, environmental-friendly and the like, the performances of the titanium-zinc panel can reach the level of foreign products, and therefore, the titanium-zinc panel has relatively strong application prospect and market competitiveness.