SU108040A1 - Method of making silicate products - Google Patents

Description

It is known that the molding of products from lime-sand solutions prepared on lime-kettle increases their density, strength and frost resistance compared to products made on ordinary lime-fluff.

This improvement in the physicomechanical properties of silicate products is due to the lower water requirement of the mixtures on the lime-kettle and self-compacting of the material due to expansion deformations.

According to the technology of manufacturing lime-kettle products, it is considered necessary not to allow (at least partial) lime to mix in the mixture before the product is molded.

For these purposes, retarder additives are added to the lime-sand mixture when mixing it with water, regardless of what the subsequent hardening conditions are (air-humidification, autoclave treatment or carbonization).

However, this method of manufacturing products subjected to heat and moisture treatment has a number of significant drawbacks.

In particular, the retarders, moving away the moment of intense quenching, cause this quenching to occur in the product prior to heat treatment or during processing.

If the products are molded prior to intensive slaking of lime, a decrease in the density and strength of the molded product and the formation of cracks are observed.

To eliminate these defects in the practice of autoclaving products, rigid covers are applied to the molds, which weakens the technological process and requires an excessive consumption of metal.

In addition, the vibration of the mixture after its mixing, especially when removing the retarders, is incomplete, since subsequent vigorous damping destroys the structure compacted by the vibrator.

The described invention provides a method for the manufacture of silicate products, ensuring their uniform strength and eliminating the occurrence of undesirable deformations in them.

The method consists in the fact that the silicate mixture on ground lime-kettle (both fine and coarse grinding) is closed with the full required amount of water, without using any quenching inhibitors.

Then, the shuttered mixture is kept for some time either in the form or in the silo, and the holding time is determined by the end of the intensive temperature rise in the mixture when the mass begins to set.

The durability of the mixture when applying quick and medium-extinguishing lime does not exceed 30-40 minutes.

This period can be significantly shortened with the use of quenching accelerators (hot water, steam heating, etc.).

Compaction of the mixture in the forms is carried out only at the end of the process of intensive slaking of lime, no further deformation is observed and the effect of compaction of the mixtures with vibration is complete.

In the manufacture of products according to the described method, the total water content in the mixture may be lower than usual, as a result of which it is possible to use hard mixtures.

This feature allows for the production of hollow products to remove liners immediately after the end of the molding.

Molded products are steamed in autoclaves without the use of lids for molds, and the steaming mode, without sacrificing the quality of the products, can be reduced by 1.5–2 hours compared to the usual one, due to more rapid lifting and lowering of pressure.

It has been established that the above techniques of technology make it possible to obtain high-strength products without any cracks or other undesirable deformations.

Subject invention

Claims (3)

1. A method of making lime-boiled silicate products with compacting the mixture in forms using one of the known methods, for example, by vibrating, centrifuging or other methods, and steaming the molded products in autoclaves, characterized in that lime lime in the sand-lime mixture is partially and briefly quench until the mixture is compacted in forms necessary for forming with the amount of water, without introducing quenching inhibitors. 2. A method of carrying out the method according to claim 1, characterized in that, when forming hollow articles (e.g., large blocks and building products), liners are immediately removed immediately after the mixture is compacted into molds. 3. Acceptance of the method according to paragraphs. 1 and 2, characterized in that the molded products are steamed in autoclaves without the use of lids for forms.