Sodium sulfite

About: Sodium sulfite is a research topic. Over the lifetime, 2548 publications have been published within this topic receiving 18523 citations. The topic is also known as: Na2SO3 & Anhydrous sodium sulfite.

Less chlorine bleaching and middle section water full closed recycling technology of alkaline sodium sulfite straw pulp

Abstract: The present invention has H2O2/H2SO4-O1-O2-D-Eop-PY bleaching process comprising first acid H2O2 pre-treatment, two sections of oxidization to eliminate lignin, chlorine dioxide bleaching, oxygen reinforced alkali extraction and final H2O2 and sodium hydrosulfite bleaching to complete the less chlorine bleaching of pulp material based on the characteristic of alkaline sodium sulfite straw pulp. On the basis of greatly reducing chlorated organic matter AOX and technological water, ion exchange, and advanced oxidation and membrane technology are combined to realize the full recovering of intermediate water. Therefore, the present invention realizes the zero drainage of papermaking water.

Preparation method of analytically pure sodium thiosulfate

Abstract: The invention relates to a preparation method of analytically pure sodium thiosulfate, comprising the following steps: (1) placing distilled water and sodium sulfite into a stainless steel reactor, heating for dissolving, heating the mixed solution until boiling, slowly adding sulphur powder to the stainless steel reactor, enabling the reacted mixture to boil for 2-3 hours until the solution does not show alkalinity, stopping heating, standing for 5-6 hours, and filtering to obtain solution A; and (2) heating and concentrating the solution A into 22-33 degree Be, cooling to obtain crystals, moving the crystals into a vacuum drier to dry at 30-35 DEG C, and taking out to obtain the finished product. In the method, the analytically pure sodium thiosulfate is obtained by synthetic reaction of the sodium sulfite and the sulphur powder, thus having simple process steps, easily controlled operation and high production efficiency; and the obtained sodium thiosulfate has low impurity content, thus the product can be widely applied to the market.

Resin for magnetic coating

Abstract: PURPOSE:To obtain the titled resin for magnetic recording video tape, etc., giving a coating film having high surface smoothness and durability, and a recording tape having excellent transportability, magnetic properties, and electromagnetic transformation property, by copolymerizing a strong acid alkali metal salt together with vinyl chloride, etc. to a specific monomer containing epoxy group. CONSTITUTION:The objective resin containing >=60(wt)% vinyl chloride, 0.1- 4.0% S- or P-containing strong acid radical and >=0.5% epoxy group is produced by reacting (A) an epoxy group-containing monomer (e.g. allyl glycidyl ether) with (B) an alkali metal salt or ammonium salt of a strong acid containing sulfur or phosphorus (e.g. sodium sulfite), and copolymerizing the resultant addition reaction mixture with (C) vinyl chloride and optionally other monomers. EFFECT:A magnetic recording medium free from the problem of head corrosion can be prepared.

Method for removing trace iodine from salt water for producing sodium hydroxide by electrolysis method

Abstract: The invention relates to a method for removing trace iodine from salt water for producing sodium hydroxide by an electrolysis method. The method comprises the following steps of: adjusting the pH value of the salt water to be 2 to 6 with hydrochloric acid to obtain solution a under the stirring condition; and adding an iodine ion reducing agent into the solution a and introducing gas into the solution a for bubbling at the temperature of between 50 and 80 DEG C, wherein the amount of the added iodine ion reducing agent is 0.3 to 1 weight percent of the solution a; and the iodine ion reducing agent is one or more of sodium sulfite, ferrous chloride and ferrous sulfate. The method has the advantages of reducing the iodine content of the salt water from 0.2mg/l to be below 0.1mg/l, along with simple process, low operating cost, safety, reliability, high economic benefit and the like, and is particularly suitable for removing the trace iodine from the salt water during ionic membrane caustic soda production.

Effect of Sulfite Dechlorination on the Accumulation of Waterborne Lead by Rainbow Trout (Salmo gairdneri)

Abstract: Chlorine can be removed from laboratory water supplies by reduction with sodium sulfite, but sulfite complexation of metals may bias aquatic toxicity tests. We tested the effect of waterborne sulfite on the accumulation of waterborne lead by rainbow trout (Salmo gairdneri). After 96 h, the blood lead levels of trout exposed to both 100 μg lead/L and 440 μg sodium sulfite/L were lower than those exposed to lead alone. The highest level of sodium sulfite having no effect on blood lead was 20 μg/L. The addition of 200–300 μg sodium sulfite/L to our water supply after charcoal filtration removed residual chlorine levels rapidly and completely. This reaction, and other possible reactions with organic matter, always reduced measureabie sulfite levels to less than 1 μg/L (limit of detection), a level much lower than those tested. Hence, sulfite dechlorination should not interfere with metal bioassays.