the properties of the thus obtained granular detergent were as shown in table 1 a product granular detergent was obtained in accordance with the same procedures and conditions as those in example 1 except that an aqueous solution of sodium silicate was mixed with an aqueous solution of auminum sulfate prior to addition thereof and said mixture was spray added the properties of the thus obtained granular detergent were as shown in table 1 2 parts by weight of sodium silicate in an aqueous solution state concentration 33 wt temperature 50 u00b0 c was added to 100 parts by weight of the starting material granular detergent of example 1 in accordance with the same procedures as in example 1 and thereafter 6 parts by weight of aluminum sulfate in an aqueous solution state concentration 20 wt temperature 30 u00b0 c was added to the same the coating time was 10 minutes this coated granular detergent was dried at 200 u00b0 c for 25 seconds to obtain a product granular detergent the properties of the thus obtained detergent were as shown in table 1 ______________________________________sodium linear alkyl 20 parts by weightbenzene sulfonatesodium u03b1 olefin sulfonate 5 parts by weightsodium silicate 15 parts by weightoptical bleaching agent 1 part by.