This Bureau of Mines report describes the results of a program to develop small, rugged mechanical dust collectors (scrubbers) with high dust collection efficiency and low energy consumption for controlling dust in coal mining operations. All of the scrubbers described are similar in configuration and are powered by 6-hp, 2,000-ft3/min vane axial fans. Air pressure differential is less than 6 inches water column. Height of the scrubbers including fan is less than 14 inches, width is less than 16 inches, and length is less than 45 inches. The flooded fibrous-bed scrubber achieved respirable (less than approximately 7 um) dust collection efficiencies of 95 percent. The small-diameter-cyclone scrubbers showed about 92 percent efficiency and can be best where excess water is a problem. The wetted brush scrubber showed 88 percent efficiency at low cost, and the wetted fan scrubber showed a slightly lower efficiency (87 percent) but offered the smallest size and cost. A suitable water droplet eliminator is described.