Development of flotation plant comprises the accomplishment of various tasks. Such tasks account for the plant equipment selection based on different calculations of equipment parameters and flotation flowsheet. In order to optimize flotation conditions, performance tests of the flotation laboratory pilot plant and flotation tests needs to be carrying out to access the influence of changing parameters as particle size, pH and reagent dosage. The present project includes investigation of the sample, obtained from tungsten-bearing skarn deposit in Spain, by froth flotation process with sodium oleate (C18H33O2Na) and oxalic acid (HO2CCO2H) as collectors. Fine-grained material, which has been obtained from grinding and milling operations on high-power size reduction equipment, was investigated for suitable particle size to process in the flotation cell.