The Camis Mining flotation plant in Turkey treats silica sand using three cleaning stages of flotation to produce a silica sand concentrate for the glass industry. Recently, in an effort to reduce the cost of collectors and improve concentrate quality by reducing iron content, various alternative collectors have been considered as replacements for the existing suite of AERO 801 and AERO 825 promoters. A series of laboratory tests was conducted on flotation plant feed materials to compare the performance of new collectors against the existing reagents. A comparative plant trial using alternative operating conditions was also conducted with the reagents to determine whether any improvement had in fact occurred. For this, the plant performance data were analysed by the paired t-test, and differences between the new flotation reagents (HA-110 + HA-150) and the existing collectors were identified in terms of iron content of the concentrate. Furthermore, the cost of the existing collectors is much higher than the new collectors and as a result the company has opted to use the new collectors at the flotation plant. (C) 2002 Elsevier Science Ltd. All rights reserved.