Method and device for preparing nano silicon dioxide by using silica gel solid waste in high-valued manner

Abstract

The invention discloses a method and a device for preparing nano silicon dioxide by using silica gel solid waste in a high-valued manner. The preparation method comprises the following steps: (1) preparing a reaction solution; (2) alkaline hydrolysis reaction; (3) carrying out double hydrolysis reaction; (IV) roasting treatment; the device comprises a shell, a stator fixed in the shell and a rotor engaged with the stator, and a fine grinding rotor is arranged at the lower end of the rotating shaft and is connected with a driving shaft of the driving mechanism. The method is simple to operate, short in technological process and easy for batch stable production; meanwhile, the equipment is simple, the cost for preparing the nano silicon dioxide is low, the energy consumption is low, the industrial prospect is better, and an important way is provided for preparing the nano silicon dioxide through high-valued conversion of the silica gel solid waste.

Description

technical field [0001] The invention belongs to the field of silicon dioxide preparation, and in particular relates to a high-value method and device for preparing nano-silicon dioxide by using silica gel solid waste. Background technique [0002] Phosphate resources in my country are often accompanied by 3% to 4% of fluorine, and a large amount of fluorosilicic acid will be by-produced in the production process of wet-process phosphoric acid and phosphate fertilizer. %. Most of the major domestic phosphorus chemical companies realize the comprehensive utilization of fluorine resources by converting the fluorosilicic acid by-product of phosphate fertilizers into hydrogen fluoride or potassium fluoride. [0003] Taking the preparation of potassium fluoride as an example, there are two main ways to produce potassium fluoride by using fluorosilicic acid as the fluorine source: one is that fluorosilicic acid reacts with potassium chloride to obtain potassium fluorosilicate, whic...

AI Technical Summary

Problems solved by technology

Since the alkali hydrolysis of silica gel solid waste and the acidification process of the alkali hydrolysis product silicate are all slow reactions, when carried out in a traditional tank reactor, the silicate and silicic acid generated during the reaction process are easy to coat and deposit. On the surface of silica gel particles, and the large reaction space of the tank reactor is likely to cause uneven local concentration and mass distribution in the reactor, insufficient mixing and reaction, and eventually lead to large particle size, uneven particle size distribution, and Problems such as high impurity content make it difficult to obtain high-quality nano-silica

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