Silicon (Si) nanostructures are considered to be the most promising anode materials for next-generation lithium batteries (LIBs) because of the very high theoretical capacity of Si. However, how to achieve a large-scale and cost-effective manufacture of them is still a big challenge. In this work, we report a facile and scalable method for preparation of two crystalline Si nanoparticle samples of 3P-2h (derived from a mixture of Cu, CuO and Cu2O catalyst) and S21-2h (derived from Cu2O catalyst). These Si samples are extracted from the wastes after reacting a metallurgical-grade Si with hydrogen chloride (HCl) gas catalyzed by the Cu catalysts. The latter is the typical industrial process used for production of organosilane monomers. The synthesized Si nanoparticles had a size of 100-300 nm. When used as anode materials for lithium ion batteries, 3P-2h delivered a reversible capacity of 636 mAh g(-1) while S21-2h showed a reversible capacity of 529 mAh g(-1) at 50 mA g(-1) after 50 cycles, better than that of the bulk Si sample. These improved electrochemical properties are attributed to the formed nanostructure and the void spaces among the Si nanoparticles which can buffer the volume expansion and shorten the diffusion path of Li-ion. This work demonstrates the feasibility for a facile, green and scalable preparation of Si nanoparticles as high-performing anode material from industrial waste.