METHOD FOR PRODUCING NANO SILICON DIOXIDE AND NANO CALCIUM CARBONATE BY USING RICE HULL ASH AND FLUE GAS OF BIOMASS POWER PLANT

摘要

Provided is a method for producing nano silicon dioxide and nano calciumcarbonate byusing rice hull ash and flue gas of a biomass power plant. The methodcomprises: addingthe rice hull ash into a sodium hydroxide solution, fully reacting at thetemperature of95-100 °C for 3-4 hours, and performing filtration; adding water into afiltrate to dilute thefiltrate, controlling sodium silicate in a system to be 8-15 wt% in silicondioxide, heatingto 60-80 °C, adding a dispersing agent, continuously feeding the fluegas of the biomasspower plant under a normal pressure condition, stirring to react for 2-4 hoursto obtain thenano silicon dioxide; mixing the filtrate and a washing liquid, adding acalciumhydroxide solution at the temperature of 50-70 °C, and stirring toreact for 0.5-2 hours toobtain the nano calcium carbonate. The particle sizes of the silicon dioxideproduct andthe calcium carbonate product which are obtained by the method are extremelysmall andcan both reach the nano level.