Prepn process of liquid polymerized ferric sulfate by means of oxidizing catalyst

Abstract

The present invention is the preparation process of liquid polymerized ferric sulfate by means of oxidizing catalyst. The process includes adding ferrous sulfate, water, sulfuric acid and sodium chlorate into reactor successively and stirring for 7-10 min. The present invention features the addition of powerful catalyst potassium permanganate, high concentration of the reactant components, fast reaction speed, high iron content and basicity of the product, low oxidant and water consumption, direct drying without washing, less drying time, low drying cost and high product quality.

Description

technical field [0001] The invention relates to a method for preparing polyferric sulfate for water treatment, in particular to a method for preparing liquid polyferric sulfate with an oxidation catalyst. Background technique [0002] Polyferric sulfate (PFS) is an inorganic polymer flocculant with superior performance. It introduces hydroxyl groups into the network structure of iron molecular clusters, and OH - Bridging to form multi-nuclear complex ions; PFS has excellent coagulation performance and the ability to remove BOD, COD and heavy metals in water, the floc sedimentation speed is fast, and can reduce the content of nitrous nitrogen; at present, PFS has been used as an excellent water purifying agent. Widely used in the field of water treatment technology. [0003] The traditional method of preparing polyferric sulfate (PFS) is to use steam heating, oxygen pressurized oxidation, and sodium nitrite to catalyze the reaction for 3-4 hours. This method has high cost, c...

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Problems solved by technology

[0003] The traditional method of preparing polyferric sulfate (PFS) is to use steam heating, oxygen pressurized oxidation, and sodium nitrite to catalyze the reaction for 3-4 hours. This method has high cost, complicated process, and is easy to pollute the environment; The Chinese patent "Method for Preparing Solid Polymerized Ferric Sulfate with Oxidant" (Application No.: 00133694.0) provides a method for preparing PFS under normal pressure, that is, 1) add ferrous sulfate to water, and then add KOH to adjust the pH above 8 ; 2) adding the solution of the above 1 to the oxidizing agent H 2 o 2 or potassium chlorate stirring, the solution temperature can reach 80°C, slightly heated and boiled for 20-30 minutes; 3) the product obtained is filtered, washed with water, and dried to obtain solid polyferric sulfate; the above method has simple process and low manufacturing cost, but due to the The process is completed under alkaline conditions. Therefore, the whole process needs to increase multi-step processes such as adjusting pH and washing, and the addition of oxidant also reaches more than 17.0% (solid), and the amount of water added reaches more than 4 times that of solid products. The drying time is extended, the drying energy consumption is increased, and the production cost is increased