3 results about "Sodium pyrosulfate" patented technology

This invention provides a production apparatus for coarse-crystalline sodium metabisulfite, comprising a primary reactor, a secondary reactor, a tertiary reactor, and a sodium carbonate liquid tank connected in series. The primary reactor has a sulfur dioxide inlet on its side wall. A flow pump is installed on the connecting pipe between the secondary reactor and the primary reactor. A gas flow meter is installed at the sulfur dioxide inlet. A pH probe is installed inside the primary reactor. A crystallizer is connected to the bottom of the primary reactor via a conveying pipe equipped with a conveying pump. The crystallizer is installed higher than the primary reactor. An overflow pipe connected to the primary reactor is located at the top of the crystallizer, and a discharge pipe with a discharge valve is connected to the bottom of the crystallizer. The coarse-crystalline sodium metabisulfite production apparatus provided by this invention can increase the particle size of sodium metabisulfite, improve the main content of the product, enhance product quality, and extend the product's agglomeration cycle.

The invention discloses an alkali polishing additive for silicon wafers. The alkali polishing additive comprises organic amine, a complexing dispersant, inorganic salt and a surfactant. The organic amine is one or more of dichloroaniline, diethanol amine and dimethylamine, and the organic amine is 1-5 parts. The complexing dispersant is one or more of sodium benzoate, sodium alginate and sodium citrate, and the complexing dispersant is 3-8 parts. The inorganic salt is one or more of sodium sulfate, lauryl sodium sulfate, sodium pyrosulfate and sodium tartrate, and the inorganic salt is 1-5 parts. The surfactant is one or more of dodecyl dimethyl betaine, sodium alkyl naphthalene sulfonate and alkyl glycoside, and the amount of the surfactant is 5-8 parts; the additive also comprises deionized water; according to the silicon wafer alkali polishing additive, the organic amine is added, the back polishing effect of the same tower footing is obtained under the condition of low weight loss, the battery efficiency is improved, meanwhile, the additive synthesis device can stir and dissolve all the raw materials evenly, and the alkali polishing additive is obtained.

The invention relates to an aluminum alloy surface environment-friendly chemical passivator and a preparation method and application thereof, and belongs to the technical field of metal surface treatment. The passivating agent is in a liquid state and is prepared from the following raw materials: 60 g / L-80 g / L of potassium permanganate, 36 g / L-54 g / L of aluminum sulfate, 0.9 g / L-1. 2 g / L of a stabilizer, 100 ml / L-200 ml / L of concentrated sulfuric acid and the balance of water in each liter of solution; the stabilizer is prepared from sodium stannate, sodium pyrosulfate and 8-hydroxyquinoline; the passivator is prepared by fully mixing the raw materials. According to the application method, the aluminum alloy with the clean and dry surface is soaked in the passivating agent, and a passivation layer can be formed on the surface of the aluminum alloy; the treatment time of the application is shortened to 0.5 min-2 min, meanwhile, the applicable temperature range is expanded to 35 DEG C-50 DEG C, and the feasibility of industrial production is greatly improved.