Ijeli yokwenziwa enezimbobo ye-silica ne-alumina, eyenziwa ngokuyeka i-silica hydrogel ijiye, iyicwilise ngosawoti we-aluminium, bese iyomiswa futhi ishiswe; isikhuthazi se-asidi esiqinile esiqhekeza umhwamuko kawoyela ube uphethiloli futhi sivuselelwa phakathi kwemijikelezo.