The Preparation of High Purity Silicon Dioxide from Boron Mud - The Solid Wastes of Boromagnesite for Producing Borax by Alkali or Soda

Abstract:

The residual rich SiO₂ slag was obtained for magnesium was leached from the boron mud by sulfuric acid. The SiO₂ was leached from the residual slag by sodium hydroxide solution. The effect of the leaching temperature and the leaching time, the ratio of the sodium hydroxide solution to slag and the concentration of the sodium hydroxide solution on the leaching efficiency of SiO₂ in the residual slag were also studied. The reasonable technical condition as follow : the leaching temperature is 130°C, the leaching time is 6 min, the concentration of the sodium hydroxide solution is 19mol·L^-1, the ratio of the sodium hydroxide solution to slag is 2.5:1. The SiO₂ leached rate can be stabilized about 85% under this condition. Silicon dioxide was produced by double carbonating the sodium silicate solution and its percentage purity is above 99%.

• Periodical: Advanced Materials Research (Volumes 233-235)
• Pages: 1296-1300
• DOI: https://doi.org/10.4028/www.scientific.net/AMR.233-235.1296
• Online since: May 2011
• Authors: Zhi Qiang Ning, Yu Chun Zhai, Hua Mei Duan
• Keywords: Boromagnesite, Silicon Dioxide, Sodium Silicate Solution

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