Fireproof expanded vermiculite and preparation method thereof

Abstract

The invention relates to fireproof expanded vermiculite and a preparation method thereof. The preparation method comprises the following steps: (1) incomplete expansion calcining is carried out on vermiculite: impurities of a vermiculite material are removed, the vermiculite material is poured into a rotary furnace with the temperature of 500 DEG C to 1000 DEG C and heated for expanding for 10 to20 seconds, and after discharge, incompletely expanded vermiculite, the bulk density of which is 800 kg/m<3> to 1200 kg/m<3>, is obtained; (2) the incompletely expanded vermiculite is added into a solvent, sufficiently stirred and ultrasonically dispersed for 20 to 40 minutes, so that a vermiculite suspension is obtained; (3) the vermiculite suspension is added with a fireproof modifier and ultrasonically dispersed for 40 to 60 minutes, wherein the fireproof modifier consists of a low-molecular carbon source, a char-forming catalyst, and a foaming agent; (4) the solution obtained in step (3) is centrifugally separated, and the precipitate is preliminarily dried, so that the fireproof expanded vermiculite is obtained. The fireproof expanded vermiculite has good fireproof performance and smoke suppression property.

Description

technical field [0001] The invention relates to a fireproof expanded vermiculite and a preparation method thereof, which can be used for preparing fireproof coatings and fireproof boards, and belongs to the field of vermiculite preparation. Background technique [0002] Vermiculite is a complex hydrous iron-magnesium silicate mineral, which is a regenerated mineral formed by hydrothermal alteration or weathering of mica minerals. The chemical composition of vermiculite is [(Mg, Fe, Al) ３ (Si,Al) ４ o １０ (OH) ２ ]・4H ２ O, but often fluctuating, belongs to the monoclinic crystal system, is in the form of flakes, with a hardness of 1-1.5 and a density of 2400-2700kg / m3. The flakes are flexible, and its most important property is that it will expand when heated. The expansion is the largest at 1000°C, and the expansion multiple is 8 to 15 times, and the highest one can reach 30 times. The density of expanded vermiculite is generally 80~200kg / m3, the thermal conductivity is 0...

AI Technical Summary

Problems solved by technology

[0003] In the prior art, a series of attempts have been made to modify vermiculite to obtain higher performance. For example, a Chinese invention patent with a notification number of 100404612 discloses a "expanded vermiculite / potassium polyacrylate-acrylamide super absorbent Composite material preparation method", this method directly uses expanded vermiculite as raw material, and prepares super water-absorbent composite material through graft copolymerization of potassium acrylate and acrylamide monomer; this method uses expanded vermiculite at normal temperature as raw material and Combining organic matter, the prepared material has the characteristics of oleophobic and hydrophilic, and cannot be used in the field of hydrophobic materials

The Chinese invention patent application with the notification number CN1800072A discloses a "dry method for rapidly preparing intercalated vermiculite". According to a certain ratio, the quaternary ammonium salt intercalation vermiculite is directly synthesized in a torque rheometer at 100-180 ℃; this method directly modifies the unexpanded vermiculite raw material, and the product density is relatively high. , carriers and organic composite fillers and other fields are limited

[0004] But at present, the use of vermiculite as a fireproof functional filler in coatings or fireproof boards is only to add expanded vermiculite directly or use it together with other fireproof coatings such as intumescent flame retardant systems and halogen-containing flame retardant systems. Research on Fireproof Modification of Stone