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With steel and other everyday materials reaching their limits in terms of structural integrity and chemical properties, new materials are needed to provide the next breakthroughs in construction and R&D. Graphene provides incredible strengths and elasticities along with amazing electrical and thermal conductivity. Graphene based materials, the so-called supermaterials, are often limited by the lack of availability due to cost and volume. This report discusses the first large scale production of an important precursor to graphene, graphite oxide (GrO). Based on improvements of Hummer’s method, this project analyses the potential challenges associated with dealing with large quantities of corrosive and reactive substances. The process described here produces 10 tons of GrO per day through eight 3-hour batches. Graphite chunks sourced directly from the mines are crushed and refined. The powdered graphite (<20 microns) is oxidized in a mixture of H2SO4 and KMnO4, which forms a reactive intermediate Mn2O7. The mixture is allowed to react for 3 h. The products are quenched using a bath of water and H2O2. The products from the quenching section go through a series of washes before the GrO product is separated and stored. The washes are processed further to recover valuable manganese compounds to reduce reagent costs. The process is not profitable at the target price of $22/kg, giving an ROI of -71%. At $25.1/kg, the ROI is 0%, and at $26/kg the process isprofitable with an ROI of 15%. The current market price of GO is $1000/kg, so the process still significantly reduces the price of GO in the market.
Date Posted: 11 May 2020