by The preparation and curing process of this experiment are carried out under laboratory conditions, which does not necessarily meet the on-site construction conditions.
Therefore, set the minimum water addition for the test to 5%, as shown in Table 1, which shows the relationship between the water addition and the volume wear rate.
Taking the construction process of on-site castable as an example, too little amount of water will lead to poor fluidity and difficult pouring.
The content of cement in the preform is high, which will make the material more dense and better wear resistance in the hydration process.
Several conclusions can be drawn from Figure 1: (1) with the increase of curing time, the volume wear rate decreases, indicating that a long time of curing has a good effect on the wear resistance of castable preforms, but it basically meets the requirements in two days without demoulding curing.
Carry out the best water addition experiment in the laboratory environment.
During the curing process, try to keep the moisture in the precast parts of castable, and water the surface properly.
For example, the curing quality in air is generally small.
Although the wear rate will decrease with the increase of time, the impact is limited; (2) Non demoulding curing is obviously better than demoulding curing, and the wear resistance of castable obtained by non demoulding curing is basically good.
(2) Amount of water added The amount of water added will vary in different environments.
The curing time and curing method are discussed in turn.
Click the “blue word” above to follow us! Test analysis: the preparation process of refractory castable preforms affects the quality of refractory castable preforms, which is closely related to the preparation process.
For example, for the high alumina bauxite clinker used, the firing process will be different from different places of origin, and the influence of artificial factors is greater.
All demoulded samples will be dried at 110 ℃ for 24 hours.
The hardening of castable preforms is closely related to the surrounding humidity.
During demoulding and curing, the preforms have a wide range of contact with the surrounding air, and the water dissipates rapidly during the curing process, which is not conducive to the higher strength of cement.
Because the cement bonded castable is used in this experiment, how to improve the bonding strength between cement and aggregate and fine powder is very important.
The castable made of different bauxite clinker may have good local wear resistance and poor wear resistance in another part, resulting in poor uniformity of precast parts of castable, Therefore, try to use the same batch of products from the same manufacturer or high aluminum homogeneous materials with better and more uniform quality…
Curing refers to the dehydration process of castable preforms, and the amount of water added is also related to the curing time.
Because of this situation in the early stage of erosion test, this paper specially studies the influence of some important operations in the preparation process on the wear resistance of castable preforms for reference.
For example, the insufficient vibration time of ceramics or refractory materials in the vibration forming process will make the bubbles in the materials unable to be discharged smoothly, resulting in the increase of porosity, and the slurry will not vibrate evenly, resulting in a large number of defects on the surface, These are the source of crack generation and propagation.
The preparation process will significantly affect the microstructure and uniformity of materials.
The test was carried out under the condition that the erosion time was 20min, the erosion angle was 45 °, and the abrasive speed was 10.8m/s.
At the same time, a batch of materials are manufactured, and the immaturity of the preparation process will lead to the difference between the advantages and disadvantages of the materials.
Fig.
Too much will also affect the strength of castable after molding, so it is necessary to add an appropriate amount.
When the water addition is less than 5%, its fluidity is very poor, the exposed degree of large aggregate is very high, and the apparent porosity of the surface is high.
For the erosion wear experiment, when studying the erosion wear mechanism of a material, because multiple samples produced do not show different properties, it will affect the results of the erosion wear experiment and even draw misleading conclusions.
1 shows the relationship between curing time (1D, 2D, 3D), curing mode (demoulding and non demoulding) and volume wear rate.
(1) Maintenance system Just like the on-site construction, even in the laboratory, it is also necessary to maintain the formed castable prefabricated parts.
During the test, it is also found that the difference of raw materials has a great impact on the precast parts of castable.
During the test, it is found that the quality of precast parts of different castables will change to varying degrees during the curing process.
It can be found that the best condition is that the amount of water is about 7.5%.
