Production and purification of silicon by calcium reduction of rice-husk white ash

Effect of soda-lime-silica glass addition on the physical properties of ceramic obtained from white rice husk ash

“…This figure shows the amorphous structure of SLS glass and a single diffuse band centred at 21°, which indicates the amorphous structure of the silica present in the WRHA treated at 700°C for 6 h. This finding is consistent with the findings of Della et al 21) Table 2 shows the chemical composition of the SLS glass and WRHA before sintering. The results illustrate that the main constituent of WRHA is silica at 94.3 wt %, which is consistent with the findings of Mishra et al, 13) who found that WRHA contains approximately 9297 wt % silica. Table 3 lists the percentages of silica in the specimens (S 1 , S 2 and S 3 ), which are also consistent with the values reported by Mishra et al 13) These results indicate that the addition of SLS glass to WRHA yielded silica elements in our samples with almost the same range of purity approximately 9297 wt %.…”

“…The results illustrate that the main constituent of WRHA is silica at 94.3 wt %, which is consistent with the findings of Mishra et al, 13) who found that WRHA contains approximately 9297 wt % silica. Table 3 lists the percentages of silica in the specimens (S 1 , S 2 and S 3 ), which are also consistent with the values reported by Mishra et al 13) These results indicate that the addition of SLS glass to WRHA yielded silica elements in our samples with almost the same range of purity approximately 9297 wt %. Furthermore, the silica content decreased with the further addition of SLS glass, most likely because of the impurities that make up approximately 40 wt % which of the SLS glass, as determined by XRF and as listed in Table 2.…”

Review on the physicochemical treatments of rice husk for production of advanced materials

“…Therefore worldwide efforts are being directed to develop a low-cost, high-volume and commercially feasible process for production of high purity silicon to be used in solar cells for photovoltaic power generation [269][270][271].One such process involves reduction of rice husk ash to produce silicon.Several approaches have been developed to produce silicon from RHs. Among the various methods, reduction of amorphous silica by metallic metals has been discussed extensivelly.The metallic elements Mg, Ca, Al and Ti can reduce SiO 2 at comparatively lower temperature and forms mixtures of condensed phase products.…”

Influence of roasting-quenching pretreatment on the rice husk silica prepared by calcination method

“…Hydrochloric acid was proven as an effective acid used in pre-treatment before calcination to remove most of the metallic impurities and producing high purity silica. Therefore, many researchers succeeded in obtaining high purity silica from RH, for instance Mishra et al [13], Della et al [14], Swatsitang et al [15], Wang et al [16] and Jung et. al [9].…”