Low-cement castable is a kind of high-performance refractory, and the correct use of low-cement castable is very important to ensure the construction quality and prolong the service life. The following are the correct use methods and precautions of low cement castable:

I. Preparation before construction

Cleaning the construction surface: ensure that the construction surface is clean and smooth, free of oil stains, sundries and loose old lining.

Formwork installation: use shaped steel formwork, and ensure that the formwork surface is flat and free from deformation. The inner side of the template can be brushed with a layer of waste engine oil, which is convenient for demoulding.

Installation of anchor: weld the anchor nail according to the design requirements to ensure that the anchor nail is firm.

II. stirring

Use clean water: the water temperature should be 10 ~ 25℃, and the water addition should be strictly controlled, generally 5.5% ~ 7%, and it should not be exceeded.

Add water after dry mixing: dry mixing for 1 minute, then add about 2/3 water to stir, and finally gradually add the remaining water according to the degree of dryness.

Mixing time: generally, the mixing time is 4-5 minutes, so as to ensure that the castable is evenly mixed.

III. Casting

Rapid pouring: the mixed castable should be transported to the pouring site quickly to avoid being exposed to air for a long time.

Blanking method: Blanking from one side of the template to prevent gaps from occurring at the bottom.

Vibration compaction: the vibration time is generally 2 minutes, and the vibration will stop when the surface of the castable no longer sinks or no bubbles escape from the surface.

Surface finishing: after vibration, scrape and shape with iron trowel before initial setting, so that the castable lining meets the design requirements.

IV. Maintenance

Time for mold removal: When the temperature in the furnace is 10 ~ 25℃, the mold can be removed 8 hours after pouring.

Natural curing: after mold removal, the castable is naturally cured to keep the surface moist.

Inspection and repair: check the pouring quality in time and repair the important parts and major problems.

V. Oven drying

Make a reasonable baking curve: low cement castable has high compactness, and it is easy to peel off or burst if it is baked improperly. Therefore, it is necessary to make a reasonable baking curve and use explosion-proof additives when necessary.

Slow temperature rise: the temperature should be raised slowly during the baking process to avoid peeling or cracking caused by the rapid discharge of water in the castable due to rapid temperature change.

VI. Storage

Dry environment: low cement castable should be stored in a dry environment to avoid moisture.

Appropriate access: access as needed before use to avoid exposing a large number of castables to the construction site.

VII. Matters needing attention

Avoid adding water repeatedly: The solidified blocks shall not be added with water repeatedly, so as not to affect the pouring quality.

Control the construction temperature: the construction site temperature should be between 5℃ and 30℃, so as to avoid too low or too high temperature affecting the construction effect.

Avoid pollution: avoid using tools such as shovels to directly contact castable during construction to prevent pollution.

By strictly following the above methods and precautions, the construction quality of low cement castable can be ensured, its service life can be prolonged, and the use requirements of high temperature industrial equipment can be met.