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Geoscience ›› 2011, Vol. 25 ›› Issue (1): 163-168.

• Water Resource and Environment • Previous Articles     Next Articles

An Experimental Study on Preparation of Nanocrystalline Wollastonite  Powders from Sodium-Calcium Siliceous Hydration Residue

 WANG  Xiao-Yan1, MA  Hong-Wen1, YU  Zi-Jian2, WANG  Xia1   

  1. National Laboratory of Mineral Materials, China University of Geosciences, Beijing100083, China
  • Online:2011-02-24 Published:2011-02-27

Abstract:

This study is focused on the efficient utilization technique of sodium-calcium siliceous hydration residue, which is remained after treating the high silicon aluminum-containing materials aegirineaugite syenite. The alkali of sodium-calcium siliceous hydration was recycled by its self- hydrolysis and decomposition in NaOH solution. The obtained diluted NaOH solution can be recycled after being concentrated. The influences of temperature, L/S ratio, initial Na2O concentration and washing times were experimentally investigated. The alkali recovery proportion is up to 90% at the conditions of 180 ℃, L/S ratio 4∶1, initial Na2O concentration 20 gram per litre and washing six to seven times. According to the differential thermal analysis and thermogravimetry of the solid residue remained after alkali recovery, the calcination temperature of preparing wollastonite is 820 ℃. Nano-crystalline wollastonite-2M was prepared, with particle size range from 50 to 100 nm, and its reaction mechanism was discussed.

Key words: insoluble potassium ore, high pressure hydrochemical process, alkali recovery, calcium silicate residue, α-wollastonite

CLC Number: