Preparation method and application of thick liquid of MgO separating agent

Abstract

The invention provides a preparation method and application of a thick liquid of an MgO separating agent. The preparation method comprises the following steps that (1), water is injected into a stirring device, the water temperature is controlled to be 0-5 DEG C, mechanical stirring is started, and the stirring rotation speed is larger than 400 revolutions per minute; (2), a water-soluble surfactant and MgO powder are added into the water in step (1), stirring is carried out to obtain the thick liquid of the MgO separating agent; the dosage of the water-soluble surfactant accounts for 0.001-0.5% on the basis of the MgO powder, and the weight ratio of the MgO powder to the water is 1: (7-10). The preparation method and application of the thick liquid of the MgO separating agent have the advantages that the mode of combining mechanical stirring and surfactant adding is adopted, the efficiency is high, the cost is low, the quality control of the thick liquid is accurate and stable, the bottom quality is ensured, a standard window of magnesium oxide is widened, and the occurrence rate of superficial pin-hole crystal exposure is controlled.

Description

technical field [0001] The invention belongs to the technical field of oriented silicon steel manufacturing, and in particular relates to a method for preparing MgO release agent slurry and its application. Background technique [0002] High-temperature annealing of grain-oriented silicon steel is generally coated with MgO as a release agent. Specifically, MgO powder is mixed with water to form a slurry, and then coated on the strip to form an MgO coating, and then high-temperature annealed. Its main function is to prevent the interlayer bonding of oriented silicon steel coils during high temperature annealing, and the second is to prevent MgO and SiO on the surface of the strip. 2 The oxide film reacts to form the bottom layer of magnesium silicate, which plays the role of insulation and improving magnetic properties. [0003] The preparation quality of MgO slurry directly affects its coating effect on strip steel, and the reaction of the bottom layer of strip steel anneal...

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Problems solved by technology

[0004] At present, in the production, the MgO slurry is generally prepared by mechanical stirring, that is, the MgO powder is poured into the stirring tank filled with water to disperse it into the aqueous solution to form a suspension. In order to make the magnesium oxide slurry uniform and form a certain proportion The small-sized MgO particles need to be stirred longer than 30 minutes, or to increase the stirring speed, or to develop different types of mechanical impellers, etc., but it is difficult to quickly achieve the target effect by mechanical stirring alone, and it is easy to cause MgO due to long stirring time. Excessive hydration, resulting in underlying defects such as dew crystals

In addition, it is reported that ultrasonic vibration equipment is installed in the stirring tank and pipeline to refine the particles in the solution, but the ultrasonic vibration can refine some useful large particles, and the formed solution particles are too uniform, and the air permeability between the steel coil layers is poor. It is conducive to the release of water vapor during the high temperature annealing process, and the installation of the ultrasonic device is difficult, the investment is large, and the maintenance is difficult

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