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.

Reductive calcining process of ferrous sulfate as byproduct of titanium dioxide

Abstract: The invention relates to a reductive calcining process of ferrous sulfate as a byproduct of titanium dioxide. The reductive calcining process comprises the following steps of: adding reductive substances, namely coke powder, sulphur and pyrite concentrate according to a certain proportion in a process of calcining ferrous sulfate to obtain solid substances, namely iron oxide red, wherein sulfur dioxide as a main component in waste gases can be used for producing concentrated sulfuric acid and anhydrous sodium sulfite after being purified, converted and absorbed, so that sulphur and iron resources in ferrous sulfate can be comprehensively recovered; and meanwhile the pollution to environment caused by long-term stockpiling of the ferrous sulfate as the byproduct in the titanium dioxide industry is eliminated, the ferrous sulfate residues can be recycled, valuable resources, such as sulphur and iron can be comprehensively recycled, the clean production requirement is achieved and the difficulties in the titanium dioxide industry are solved.

Method for purifying lateritic nickel ore leach liquor

Abstract: The invention discloses a method for purifying lateritic nickel ore leach liquor, which comprises the following steps: neutralizing lateritic nickel ore leach liquor with lime milk or lime powder to remove iron; after carrying out solid-liquid separation, neutralizing with sodium hydroxide solution until the pH value reaches 7.5-8.5, thereby precipitating nickel, wherein magnesium stays in the solution to be separated from nickel; dissolving nickelous hydroxide with sulfuric acid, adding sodium sulfite and barium carbonate, and regulating the pH value of the nickel sulfate solution to 2.0-2.5; simultaneously adding the obtained nickel sulfate solution and sodium hydroxide solution into a stirring tank, wherein the pH value of the solution in the stirring tank is kept at 5.0-6.0 by controlling the addition amount of the sodium hydroxide solution; and carrying out solid-liquid separation on slurry obtained after reaction, wherein the obtained nickel sulfate solution can be sent to a treatment procedure for further extracting nickel. Compared with a common process, the method disclosed by the invention has obvious advantages in the aspects of removing impurities in lateritic nickel ore leach liquor and increasing filtering rate of slurry.

Preparation and characterization of cellulose/glycidyl methacrylate/acrylic acid cation exchange composites

Abstract: Acrylic acid (AA)/glycidyl methacrylate (GMA) mixtures were bulk polymerized in the presence of cellulose in order to prepare cellulose/GMA/AA cation exchange composites using sodium persulfate as an oxidant, alone or in conjunction with sodium sulfite, sodium thiosulfate, sodium metabisulfite or glucose as a reductant. The presence of the reductant has the effect of shortening the polymerization time, expressed as the solidification time (ST), with little improvement in the polymerization extent, expressed as percentage total conversion (%TC), as well as the percentage yield and the carboxyl content of the crude and the purified composites. Sodium sulfite was selected as the the reductant that can achieve best polymerization. The effect of the concentrations of “sodium persulfate/sodium sulfite, redox system, acrylic acid and glycidyl methacrylate” and temperature on the formation of the composite were investigated. Four cation exchange composites were prepared and characterized by investigating their potentiometric titration, water solubility and swellability as well as durability.