The effect of several parameters on the recovery of silicon dioxide from calcined boron mud（CBM）such as stirring speed, temperature, sodium silicate concentration, and carbonation time was studied. The recovery of s...The effect of several parameters on the recovery of silicon dioxide from calcined boron mud（CBM）such as stirring speed, temperature, sodium silicate concentration, and carbonation time was studied. The recovery of silicon dioxide is 88 % when the stirring speed is450 r min-1, temperature is 60 °C, sodium silicate concentration is 1 mol L-1, and the carbonation time is 6 h.The effect of carbonation time on the recovery of silicon dioxide is divided into three kinetic regimes, and the carbonation process of sodium silicate solution follows a second-order reaction based on the double-film theory model. The apparent rate constant of the three kinetic regimes is 0.064, 3.178, and 1.130 L h mol-1, respectively.The amorphous SiO_2 products obtained by carbonating the purified solution have 99.6 % purity and are spherical with diameters of about 100 nm.展开更多
基金financially supported by the National Natural Science Foundation of China(No.51204037)the Fundamental Research Funds for the Central UniversitiesChina(No.N140204016)
文摘The effect of several parameters on the recovery of silicon dioxide from calcined boron mud（CBM）such as stirring speed, temperature, sodium silicate concentration, and carbonation time was studied. The recovery of silicon dioxide is 88 % when the stirring speed is450 r min-1, temperature is 60 °C, sodium silicate concentration is 1 mol L-1, and the carbonation time is 6 h.The effect of carbonation time on the recovery of silicon dioxide is divided into three kinetic regimes, and the carbonation process of sodium silicate solution follows a second-order reaction based on the double-film theory model. The apparent rate constant of the three kinetic regimes is 0.064, 3.178, and 1.130 L h mol-1, respectively.The amorphous SiO_2 products obtained by carbonating the purified solution have 99.6 % purity and are spherical with diameters of about 100 nm.
