Filter aid including specific silica gel

摘要

The present invention provides a novel filter aid which has excellent filtration properties and forms a stable cake layer on a filter member. The filter aid includes a flake-like, scale-like, or rod-like silica gel as a primary component thereof. The silica gel is approximately 5 through 100 micrometer in grain diameter and has a pore volume of approximately 0.2 through 1.5 ml/g and a specific surface area of approximately 100 through 1,000 m2/g.