JP2002311018A - Method for measuring adhesion strength of coating of brick for cement kiln - Google Patents

Abstract

PROBLEM TO BE SOLVED: To simply and quantitatively measure the adhesion strength of coating adhered to a refractory brick used in an actual furnace. SOLUTION: A surface of different inclination to a horizontal surface of the brick having the horizontal surface and the surface of different inclination to the horizontal surface is set to be horizontal, and in this condition, raw cement materials are placed on this surface, and a brick having a surface with the same inclination as that of this brick is placed thereon, baked and cooled. By measuring the force to be applied so as to shift an adhesive surface from the direction perpendicular to the horizontal surface of the adhered brick, the adhesion strength of the cement coating to the brick is measured. The adhesion strength of the coating can be simply and quantitatively measured with excellent reproducibility.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

FIELD OF THE INVENTION The present invention relates to a method for determining the adhesion properties of a refractory coating for a cement rotary kiln.

[0002]

2. Description of the Related Art In a cement rotary kiln, a mineral mainly derived from a cement raw material adheres to the surface of a brick used to protect the brick from the cement raw material heated to a high temperature, thereby improving the service life of the brick. Are known. This deposit is referred to as coating, and one method of improving durability is to attach the coating stably.

[0003] The measurement of the adhesion strength of brick and coaching is
Conventionally, various methods have been used, but at present, there is no method that can measure quantitatively simply. Conventional methods include a rotating drum method and a sandwich method.

In the rotating drum method, a test brick is lined inside a drum in a ring shape, heated by a burner while rotating the drum, and a cement raw material is added thereto to adhere a coating. It cools after a predetermined time, and observes the state of adhesion of the coating.

[0005] The sandwich method uses a cubic brick 2
This is performed by sandwiching a cement raw material between the individual pieces, firing the mixture, cooling the mixture, and measuring the bending strength of the bonded brick.

Further, as disclosed in Japanese Patent Application Laid-Open No.
There is also a method in which the coating is distributed on the brick surface so as to form islands, and the strength at the time of scraping off the coating attached to the islands is measured.

[0007]

However, these methods have problems in simplicity, quantitativeness, and reproducibility.
The rotating drum method is not quantitative to determine the state of adhesion by visual observation. Further, the sandwich method is greatly affected by the state of cracks generated at the initial stage when measuring the bending strength of the bonded portion, so that the variation is large and the reproducibility is poor. Further, according to the method of Japanese Patent Application Laid-Open No. 6-138021, the temperature at which the coating can be applied is limited to 1400 ° C. or higher,
The fineness of the island formations is extremely qualitative and complicates the measurement.

An object of the present invention is to solve the above-mentioned problems and to provide a simple and quantitatively reproducible coating adhesion test method.

[0009]

According to the method of measuring the adhesion strength of a coating according to the present invention, a horizontal plane (hereinafter abbreviated as A plane) and a plane having an angle in the range of 30 to 60 ° with respect to the horizontal plane (hereinafter abbreviated as B plane) are used. With the B surface horizontal, place the cement material on the B surface so as to have an even thickness, and apply a brick having the same inclination as this brick so that the A surface and the B surface of each brick are parallel. After baking at a predetermined temperature and cooling, a force perpendicular to the surface A is applied to measure the strength at which the bonded surface shifts.

[0010]

In the present invention, the inclination of the plane B is 30 to 60 degrees.
Is preferable. If the inclination is less than 30 °, the coating becomes difficult to shift, cracks are formed in the layer during pressurization, and the adhesive strength cannot be measured correctly. On the other hand, when the angle is larger than 60 °, the measured value of the force at which the layer is easily split and becomes small becomes large, and the error becomes large.

[0011] As the cement raw material to be used, a mixed one can be used because it is generally used in an actual machine.
Since this mixture shrinks due to decarboxylation when heated, it is preferable to previously calcine the mixture at 1000 ° C. for 5 hours.

[0012]

FIG. 1 shows a state in which a cement raw material is sandwiched between bricks, fired and cooled. FIG. 2 shows a state when the strength is measured.

The surface A of the brick in the figure is, for example, 60 mm × 6.
Cut out to 0mm, so the B side is 60mm
× about 85 mm. The thickness of the cement raw material sandwiched between the bricks is about 3 mm, and the two bricks shown in FIG. 1 are fixed from below so that the surface B of the lower one is horizontal. After cooling, the strength is measured from the direction of the arrow as shown in FIG. 2 by a generally used strength measuring tester, which is very simple.

If the inclination of the surface B with respect to the surface A is less than 30 °, the coaching will be compressed without causing a shift in the adhesive surface during the strength measurement, and the adhesion strength of the coating cannot be measured. On the other hand, if the angle is larger than 60 °, the adhesion surface is immediately displaced by a small force, so that the adhesion strength varies greatly.

Table 1 summarizes the adhesion strength of magcro, spinel and dolomite brick when fired at 1400 ° C. The inclination of the plane B with respect to the plane A is 45 °. In actual equipment, it has been found that dolomite, magcro, and spinel adhere in the order of coating. As shown in Table 1, the method according to the present invention provided results suitable for an actual machine and small variations.

[0016]

[Table 1]

Table 2 shows the adhesion strength of spinel bricks having different alumina contents when fired at 1350 ° C. The inclination of the plane B with respect to the plane A is 45 °. According to the method of the present invention, the strength at a desired adhesion treatment temperature can be measured.

[0018]

[Table 2]

[0019]

According to the present invention, it is possible to easily and quantitatively measure the adhesion of the coating of the brick compared with the conventional method, and it is also reproducible, and the method for evaluating the adhesion of the coating is used. It is superior as a method.

[Brief description of the drawings]

FIG. 1 is a diagram showing the position of a brick when a cement raw material is sandwiched between the bricks and the position of the brick during firing and cooling.

FIG. 2 is a view showing the position of a brick when measuring the adhesive strength of a coating.

[Explanation of symbols]

1,1 '… Brick 2… Cement raw material 3… Coaching

Claims (1)

[Claims] 1. A brick having a horizontal plane and a surface having an angle in the range of 30 to 60 ° with respect to the horizontal plane is 30 to 60 ° with respect to the horizontal plane of the brick
In a state where the surface having an angle of the range is horizontal, a cement raw material is placed on this surface, and a brick having a surface having the same inclination as the brick is placed so that the horizontal plane is parallel, fired, cooled, and bonded. A method of measuring the adhesive strength between brick and coaching by measuring the force applied to the adhesive surface so as to shift the adhesive surface from the direction perpendicular to the horizontal plane of the brick.