Modified porous steel slag for rubber filler and preparation method thereof

The invention discloses a modified porous steel slag for rubber filler and a preparation method thereof, and belongs to the field of recycling utilization of resource. The modified porous steel slag comprises phosphoric acid solution, silane coupling agent, stearic acid and steel slag; the mass percent of the phosphoric acid solution is 70-90%, the grain diameter of the steel slag is 2.2 miu m-115.0 miu m. The modified porous steel slag is prepared by firstly mixing the phosphoric acid solution with the steel slag, and stirring it for 4h-6h under the constant temperature, and acquiring the porous steel slag; then mixing the porous steel slag with the silane coupling agent and stearic acid; and mixing the components by a constant temperature magnetic mixer and acquiring the modified porous steel slag. The modified porous steel slag solves the problems that price of the main fillers carbon black and white carbon black of the existing rubber industry is very high, the steel slag is directly added in the rubber a