oil sample 3 was mixed using 10 parts by weight of sawdust and 5 43 parts by weight of 29 calcium chloride liquor and 3 75 parts by weight of oil sample 4 was mixed using 10 parts by weight of sawdust and 10 85 parts by weight of 29 calcium chloride liquor and 1 88 parts by weight of oil sample 5 was mixed using 10 parts by weight of sawdust and 10 85 parts by weight of 29 calcium chloride liquor sample 6 was mixed using 10 parts by weight of sawdust and 16 28 parts by weight of 29 calcium chloride liquor sample 7 was mixed using 10 parts by weight of sawdust and 21 7 parts by weight of 29 calcium chloride liquor the seven samples were tested for dust retention effectiveness by using powdered bentonite dust in air agitation in a closed vessel to maintain the dust in suspension sweeping compound was added to the bentonite dust mixture in the closed vessel until 100 of the dust was removed in a pre weighed filter a measured amount of sweeping compound was added to the vessel and the dust and the sweeping compound was agitated with air the.