Method for preparing smectite inorganic gel by mechanochemical modification

Abstract

The invention discloses a method for preparing a smectite inorganic gel by mechanochemical modification, which comprises the following steps: adding water into the smectite raw material to prepare a slurry with the concentration of 5-20 wt%, stirring and dispersing uniformly, and pretreating with an ion exchange resin to obtain a pretreated smectite slurry; adding a modifier which is 0.6-1.2 times of smectite CEC, and stirring and dispersing uniformly; feeding the slurry into a wet-process superfine treatment device to perform superfine treatment, thereby obtaining the smectite slurry of which the particle size distribution is D50<=1.0 mu m and D90<=5.0 mu m; and adding an electrolyte which accounts for 0-5 wt% of the smectite into the superfine slurry, and stirring and dispersing uniformly to obtain the target product. The method obviously enhances the water dispersity, suspension stability and thickening property of the smectite, and especially has obvious improvement effects on high-level charged smectite.

Description

technical field [0001] The invention belongs to the field of deep processing of montmorillonite, and in particular relates to a method for preparing montmorillonite inorganic gel through mechanochemical modification. Background technique [0002] Montmorillonite, also known as microcrystalline kaolinite, is the main component of bentonite ore. It is composed of two layers of silicon-oxygen tetrahedral sheets and a layer of aluminum-oxygen octahedral sheets sandwiched between them. It can be observed under a scanning electron microscope that the thickness of the sheet is only about tens of nanometers. It is a natural nano-mineral Material. [0003] The heterovalent homogeneous substitution in the lattice is the most basic and important structural characteristic of montmorillonite. In addition to being replaced by aluminum, silicon in silicon-oxygen tetrahedron can also be replaced by Fe 3+ etc instead. Aluminum in AlO octahedra can be replaced by unequivalent cations Fe ...

AI Technical Summary

Problems solved by technology

However, there are many problems in this traditional sodium modification method: 1) the traditional method does not remove calcium and magnesium ions in montmorillonite, which still exist in the form of interlayer cations or carbonates, which to a large extent It affects the water dispersion effect of montmorillonite, and the suspension, viscosity and particle size distribution of the slurry after hydration of montmorillonite are poor

2) The replacement of calcium ions between montmorillonite layers by sodium ions is a gradual process. The cation exchange efficiency is low and the time is long, which can last for several months or a year, and the thoroughness and uniformity of the reaction are difficult to guarantee

This greatly restricts the improvement of production efficiency, and seriously affects the sodium effect and stability of the product

3) The naturally produced bentonite ore, during the geological formation process of hundreds of millions of years, is affected by the natural environment, climate, etc., the particle agglomeration phenomenon is obvious, and the nano activity is lost

However, a large amount of acid-base hydrothermal treatment will seriously damage the crystal structure of montmorillonite, resulting in significantly worse thickening and suspension; and cause environmental pollution and equipment corrosion

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