The Preparation Of Nano SiO₂ From Laterite Nickelor

Nickel is the most valuable metal in the laterite nickelor and the aimable production in the traditional technics. However, nickel is less in laterite nickelor,thus there are a great deal of residue in the process of nickel production,they occupy the land and pollute the environment. On the other hand,there are a great number of silicate compounds in the laterite nickelor,if we make the best of them,we can not only get various product of silicon and increase the value in use of laterite nickelor,but also decrease the waste discharge and accord with the request of circular economy,cleaner production and improving comprehensive utilization of mineral resources.We produced the nano SiO2 by carbonization which got sodium silicate solution and the CO2 gas as raw materials.We studied the influence of stirring speed,flow rate of CO2,reaction time,reaction concentration and reaction temperature on granularity of SiO2 and the rate of translation,and discussed the influence of ethanol on the appearance of production.We got that the order with respect to time was 2.65 and the order with respect to concentration was 2.03 by the method of differential coefficient. We also got that the activation energy was 55.12kJ·mol-1.Taking the post-processing way of high-temperature calcination on SiO2,we studied the influence of calcination temperature on the crystalline of SiO2,the hydroxide radical desorption,the rate of weightlessness,appearance of SiO2,the result showed:SiO2 was amorphous before 1200℃,it illuminated that the thermal stability of SiO2 was very high,crystalline-amorphous transition began until 1200℃and at last changed completely in 1300℃.The desorption of hydroxide radical was proportional to the calcination temperature. The rate of weightlessness was proportional to the calcination temperature, the rate of weightlessness descended when the temperature was 1300℃.There were no changes on appearance of SiO2 after calcination in 1000℃, the appearance of SiO2 was chaged until 1300℃,it featured blurred edge.