Porous "silicon carbide diatomite" particles

Diatom are algaes which are able to grow a skeleton containing silicon oxide. Those algae form large sediments of so called diatomaceous earth (diatomite) which are mined for industrial purpose. Diatomite is built up from silicon oxide particles which have preserved the original shape of diatom skeletons. The unique behavior of diatomite concerning packing, absorption and consistence favors its use in numerous technical applications. But silicon oxide may not be applicable for technical processes which need a better chemical and thermal resistance than silicon oxide offers so that different diatomite like materials would be advantageous in these cases. The idea of the presented work is the conversion of the diatomite particles into silicon carbide particles together with a conservation of the specific particle shape in order to use the obtained silicon carbide diatomite in the same way as natural diatomite. The proposed way to the desired product is a homogeneous mixture of diatomite with a carbon precursor, the rapid heating and reaction of the components avoiding melting or sintering of the original diatomite particles. The obtained porous silicon carbide particles can be used for filtration processes. Furthermore they might be used as raw material for ceramics with very specific porosity. A specific advantage could be that the porosity can be tailored with concern to the shape, arrangement and total pore volume.