Improvement measures:
1, control the quality of raw materials;
2, used strictly in accordance with a reasonable proportion of secondary material;
3, metal melting and refining of high-quality agents;
4, using ceramic filters;
5, vacuum melting transportation;
6, ceramic spoons, crucibles, protection tube, discarded ferrous material tool;
7, regular cleaning of moulds, tools, face;
8, high quality mould release agent support materials;
9, keeping the environment clean.
