Method for preparing nano white carbon black from coal gangue

The invention relates to a method for preparing white carbon black from coal gangue, belongs to the technical field of coal chemical industry, and aims at overcoming the shortcomings of expensive raw materials and high production cost in the process for preparing nano white carbon black by using the traditional method. The method comprises the steps of: based on coal gangue as a raw material, carrying out high-temperature activation, nitric acid dissolution, burning and the like to extract silicon dioxide; corroding extracted silicon dioxide with hydrogen fluoride generated by reacting concentrated sulfuric acid and sodium fluoride so as to generate silicon tetrafluoride gas, reacting the silicon tetrafluoride gas with an aqueous solution with a surfactant dissolved to generate silicon gel, cleaning, drying and burning to remove water so as to produce the required nano white carbon black product. According to the method provided by the invention, the waste recycling of coal gangue is realized, and the cost for preparing nano white carbon black is lowered; and the particle size of the obtained product achieves a nano scale, and the indexes of the obtained product achieve the ministerial standard HG-1-125-64 or enterprise standard.