3. Difference of heat resistance between basalt rock wool insulation board and slag rock wool board.

The thermal insulation performance of slag rock wool insulation board is good. When its working temperature exceeds 675 ℃, the cooling process is slow, which makes the transformation density of internal structure decrease from 3.28 to 2.97, and the volume expands by about 10%, causing the slag rock wool insulation board to pulverize and disintegrate. The basalt rock wool insulation board does not have this transformation, and its use temperature is up to 800 ℃, and its softening temperature is 900~1000C.
     4. Difference of corrosion resistance between basalt rock wool insulation board and slag rock wool board.
One of the main functions of the blast furnace in smelting is desulfurization to prevent iron from being brittle during use. These removed sulfur remain in the blast furnace slag in the form of CaS and then enter the slag wool, with the content of about 5%. When the slag rock wool insulation board is used in an environment with high humidity, the CaS in it will be decomposed into Ca (OH) 2 and H2S when meeting with water. Ca (OH) 2 makes the water alkaline, further reducing the water resistance of the slag wool. H2S gas can be dissolved in water to generate hydrogen sulfuric acid, which will play a corrosive role when contacting with metal. Basalt rock wool insulation board is made of basalt or diabase. Except for the trace sulfur brought in by coke during smelting, there is no more sulfur source, so it has no corrosion effect on metals.