The present invention is that a continuous slag-discharging device is mounted on the yellow phosphorus electric furnance. As the slag is flowing through the continuous slag-discharging hole, the molten-slag stream through the guide pipe is aimed at the high-speed air injection tube nozzle or the upper end of the four-roller high-speed centrifugal wool-making machine, and then it is directly made into the calcium-alumina silicate fibres thereby. And then an appropriate amount of adhesive solution is added in the above-mentioned material, and the low cost, light-type hard or semi-hard heat-insulating plate, acoustic board, decorative board, high-temp. insulating plate and heat-insulating material for pipes can be made. |