We have been manufacturing a special type of industrial special electric furnaces such as rotary kiln, glass melting furnace, vacuum furnace for a decade. Such a firing furnace can be widely used in the field of recycling waste lithium secondary batteries as well as manufacturing secondary battery cathode materials. Especially, we are very specialized in making continuous firing furnaces where the atmosphere inside the furnace should be controlled. When slicing the silicon ingot to make a silicon wafer in PV industry, a large amount of silicon kerfs are generated. Based on our own furnace technology, we are making nano-sized silicon powder for anode material of lithium ion secondary battery using these silicon kerfs.