What are the catalysts for making SiC from rice husk?
Rice husk is a by-product of rice mill processing, accounting for about 20% of the total output of rice. At present, rice husk is more than 60 Mt of rice husk all over the world. Therefore, many places regard rice husk as a waste, which not only wastes resources, but also pollutes the environment. It is of great significance to study and solve the reasonable utilization of rice husk and turn waste into treasure. Using rice husk as raw material can be produced in excess of the value of its own several chemical products, especially the cutting-edge science indispensable high-tech products, which is one of the important products of silicon carbide, and the production process is simple, easy to control, low cost, greatly improves the utilization ratio of rice husk. (rice husk, silicon carbide) (rice husk * SiC)
A method for manufacturing silicon carbide using carbonized rice husk as the main ingredients: Carbonized rice husk and coke silica into sodium hydroxide and water by hydrothermal method, in 200 - 300 DEG C to 24 + 5 hours temperature, pressure and 50 - 1500 ATM, synthesis of silicon carbide. The present invention has low reaction temperature and low cost, and is suitable for mass production in industry.
The rice husk is crushed, in the temperature range of 650 to 700 DEG C, the carbonization process in furnace will be closed after the first rice husk carbonization catalyst, according to a certain weight ratio and adding, evenly mixed, the mixture is filled in the graphite crucible, the carbon fiber arranged on the upper part of the mixture, cover crucible cover. The graphite crucible is placed in a vertical vacuum furnace with graphite as the heater, and argon gas is used to protect the silicon carbide whisker on the carbon fiber. The invention realizes the automatic separation of whisker and powder, and the whisker is attached to the upper part of the carbon fiber in the powder material, and does not need to be separated from the residual carbon or other powder for two times. The obtained whisker has a high direct crystal rate and a simple process.
