7 Devices for dispersing and spraying chemicals and wet and dry chemical slurries for the purpose of reducing heavy metal emissions from power plants, namely, impeller-driven pumps, positive displacement pumps, negative displacement pumps, centrifugal pumps, power-operated sprayers, flow regulators being parts of machines, and industrial chemical or wet and dry chemical slurry spray systems comprised of pumps, pump controllers, nozzles, tubing and valves; devices for milling chemicals and wet and dry chemical slurries, namely, coarse- and fine-grind grinding machines