Why Choose a Screw Conveyor for Bulk Material Handling?

Bulk Material	Typical Bulk Density (kg/m³)	Flow Characteristics	Suitability for Screw Conveying	Recommended Conveyor Considerations	Typical Applications
Portland Cement	900–1,500	Fine, dry, cohesive, and potentially dusty	Excellent	Use enclosed construction, dust-tight seals, and suitable feed control. Avoid moisture ingress to prevent buildup.	Concrete batching, mortar production, dry-mix processing
Fly Ash	700–1,000	Fine, powdery, aeratable, and dusty	Excellent	Provide effective sealing and ventilation. A controlled conveying speed helps reduce dust generation.	Power generation, cement production, ash handling
Limestone	1,200–1,600	Granular or crushed; moderately abrasive	Excellent	Select abrasion-resistant flights or liners when the material contains coarse particles.	Quarries, cement plants, aggregate processing
Sand	1,400–1,700	Free-flowing to slightly cohesive; abrasive	Excellent	Use wear-resistant components and inspect troughs, flights, and hanger areas regularly.	Foundries, glass production, construction materials
Gravel	1,500–1,900	Coarse, free-flowing, and highly abrasive	Good	Best for controlled, short-to-medium conveying distances. Verify particle size and use heavy-duty construction.	Aggregate handling, concrete production, mineral processing
Wheat	720–820	Granular, free-flowing, and moderately fragile	Excellent	Use food-compatible materials where required and moderate screw speed to limit kernel damage.	Grain storage, flour milling, feed production
Corn and Maize	680–800	Granular, free-flowing, and susceptible to breakage	Excellent	Use low-to-moderate speed and avoid excessive drop heights or overfilling.	Grain handling, animal feed, food processing
Animal Feed Pellets	550–750	Granular, free-flowing, and moderately fragile	Excellent	Choose a low-speed configuration when pellet integrity is important. Keep the conveying path clean and dry.	Feed mills, agricultural processing, bulk storage
Wood Chips	180–350	Lightweight, irregular, and compressible	Good	Use a large-diameter or heavy-duty screw where bridging or irregular loading may occur. Monitor for blockage.	Biomass plants, pulp and paper, wood processing
Sawdust	150–300	Light, dusty, cohesive, and compressible	Good	Use enclosed conveying, dust control, and appropriate inlet geometry. Prevent compaction and buildup.	Woodworking, pellet production, biomass processing
Sugar	700–900	Granular, free-flowing, moisture-sensitive	Excellent	Use sanitary construction where applicable and maintain low humidity to prevent caking.	Food processing, confectionery production, beverage manufacturing
Salt	1,100–1,300	Granular, free-flowing, mildly corrosive when moisture is present	Excellent	Consider corrosion-resistant materials and protect the conveyor from water and condensation.	Food processing, chemical production, de-icing material handling
Plastic Pellets	500–700	Granular, free-flowing, and relatively clean	Excellent	Control speed and transfer points to reduce pellet degradation and static-related dust.	Plastic compounding, injection molding, extrusion
Wet Filter Cake	800–1,600	Moist, cohesive, sticky, and difficult to flow	Conditional	Use a suitable shaftless or specialized screw design when conventional flights may plug or accumulate material.	Wastewater treatment, mineral processing, industrial filtration
Sludge	900–1,200	Wet, cohesive, variable, and potentially corrosive	Conditional	Confirm moisture, viscosity, and solids content. Corrosion-resistant construction and cleanout access may be necessary.	Municipal treatment, industrial wastewater, dewatering systems