Cement Import Terminals Are Growing. Is Your Conveying System Ready for the Distance?
Walk around any cement import terminal and you'll notice something: very little of the material moves by gravity alone. Cement comes off a ship into a dome or silo, gets moved to a loadout silo, goes into trucks or railcars, then often gets unloaded again at an inland terminal and conveyed into another silo. Every one of those steps is a handoff, and a lot of them run through a pipe.
That's why terminal owners who treat conveying as an afterthought usually end up paying for it later.
The short version: US cement imports cover close to a quarter of the country's demand, and new import terminals keep getting built. Terminals depend on pneumatic conveying to move cement and slag over long distances between domes, silos, and truck and rail loadout. Getting that right means planning for pressure loss, air expansion, pipe wear, moist conveying air, and 24/7 uptime from day one.
Why terminals are getting so much attention
The US simply doesn't make enough cement to meet its own demand. According to USGS figures, net cement and clinker imports were about 27 million short tons in 2025, or 24% of shipments.
And the buildout is still going. The US keeps adding cement import capacity even though demand has slowed, and industry voices at Intercem Americas this year compared the amount of new and announced terminal capacity to the last big buildout cycle in the 2000s.
Look at a recent project and you can see how many conveying steps are involved. Silvi Cement is building an import terminal at Morehead City, North Carolina, with two 100,000-metric-ton domes for Type I/II cement and Grade 120 slag, plus around-the-clock truck loading and direct rail loadout. The company is also opening a rail-served distribution facility in central Ohio that's meant to handle more than 250,000 metric tons a year, with its Bristol, Pennsylvania terminal supplying both by rail in the meantime.
That's a ship, domes, loadout, rail, and inland silos. Material is moved and moved again.
A terminal is only as fast as its slowest handoff
At a cement plant, conveying supports production. At a terminal, conveying basically is the operation. If a transfer line from the dome slows down, the loadout silos run low and trucks start stacking up at the gate. Customers notice that quickly.
That changes how you should think about the system. Three things matter more at a terminal than almost anywhere else:
Throughput you can count on. Not the nameplate number, but what the line delivers day after day with real cement in real weather.
Uptime around the clock. Many terminals load trucks 24/7. Planned maintenance windows are short, and unplanned ones are expensive.
Flexibility. Terminals increasingly handle more than one product, like portland cement and slag, and often need to send material to several destinations.
What makes long-distance conveying hard
Moving cement a few hundred feet is one thing. Moving it across a large terminal site is another. Here's what changes as the line gets longer.
The air expands as it travels. Pressure drops along a pneumatic line, and as it drops, the air expands and speeds up. By the far end, the velocity can be much higher than at the pickup point. That's a big reason long lines wear faster near the end, and why designers often step up the pipe diameter along the route to keep velocity under control.
Pressure loss adds up. Every foot of pipe and every bend costs pressure. Long lines need more air at higher pressure, which puts more demand on the blower or compressor and more strain on the feeder sealing the line.
The feeder has to hold the line. At higher conveying pressures, a rotary valve that leaks air becomes a real problem. The air bypass cuts capacity and makes the feed unstable. For long, high-pressure lines, dense phase pressure vessels are often the better choice.
Bends take the beating. Cement and slag are abrasive. The more bends in a long route, the more places for wear, and a single blown elbow can shut down the whole transfer.
Wet air can ruin your day. Compressing air heats it up, and when that warm, moist air cools in the pipe, condensation can form. With cement, that means buildup and hardened material inside the line. Air cooling and drying is not optional in a lot of terminal applications.
Dilute, dense, or something in between?
There's no single right answer, but here's how it usually shakes out at terminals.
Dilute phase is simple and flexible, and it works well for shorter transfers and for pressure or vacuum unloading from multiple pickup points. The tradeoff is higher velocity, which means more wear and more energy on long, abrasive runs. Though in many circumstances Dilute systems can be used in high abrasives from companies like Delta Ducon for materials up to specific distances and rates.
Dense phase moves material in slugs at low velocity. For long-distance transfers of abrasive materials like cement and slag, that usually means much less wear on pipe and fittings and less air per ton moved. Delta Ducon's dense phase lineup, strengthened by our partnership with Clyde Pneumatic Conveying, brings in technologies like the Denseveyor, D-Pump and Spheri Dome Valve. You can see the full range on our pneumatic conveying systems page.
Semi-dense phase sits in the middle. It's a good fit when you want less wear than dilute phase but don't need the full dense phase setup.
The right choice depends on the material, the distance, the capacity, and how many destinations you need to feed. A good supplier will talk you through the tradeoffs instead of pushing whatever they happen to sell.
At Delta Ducon, having the ability to offer all 3 options allows us to give you the best engineered solution for your plants needs and not just what another copmpay specializes in.
Rail is part of the story too
A lot of terminal material eventually moves by rail, which means someone at the other end has to unload it. Railcar unloading is often where terminals lose time, especially in cold weather or with older cars.
Pneumatic unloading is clean and enclosed, which matters for dust control, and it lets you send material straight into silos without mechanical conveyors. We wrote a practical guide to railcar unloading options for dilute and dense phase systems if you're weighing the options.
Terminals are starting to blend, too
With slag and other SCMs showing up at terminals next to portland cement, more operators are asking whether they can blend on site instead of shipping blended product in. That adds dosing and blending equipment to the conveying system, but it also gives terminals more products to sell from the same site.
Delta Ducon's on-site cement blending systems handle 10 to 150 TPH with conveying distances up to 500 meters, supporting both short-batch truck loading and continuous silo filling. More details are on our cement, mining and minerals page.
Questions to ask before you build or expand
If you're planning a new terminal or adding capacity, these questions will save you trouble later:
What's the real sustained throughput, not the peak rating, for each transfer line?
How will velocity be managed over the full length of the longest line?
How will the conveying air be cooled and dried?
Which components will wear first, and how fast can they be replaced?
Can the system handle a second product, like slag, without cross-contamination?
How easy is it to add a destination later?
About Delta Ducon
Delta Ducon has been building pneumatic conveying systems and severe-duty components for heavy industry since 1921, and we're headquartered in Malvern, Pennsylvania. For terminal applications, that means dilute, dense and semi-dense phase systems, truck and railcar unloading, Extreme Duty Rotary Valves, PERMA/flo abrasion-resistant pipe and elbows, KG Diverter Valves, and air dryers and coolers, all from one supplier.
Frequently asked questions
How far can cement be conveyed pneumatically? It depends on the system type, the material and the design, but long transfers across a terminal site are common. Dense phase systems are usually preferred for the longest runs of abrasive materials because they use lower velocities.
Why does wear get worse near the end of a long conveying line? Because air expands as pressure drops along the pipe, which speeds up the flow. Higher velocity near the end means harder impacts on pipe walls and bends.
Is dense phase or dilute phase better for a cement terminal? For long, high-capacity transfers of cement and slag, dense phase usually wins on wear and energy. Dilute phase is often simpler and works well for shorter runs in both pressure and vacuum unloading.
Why do cement terminals need air dryers or coolers? Compressed air carries moisture and heat. If it condenses inside the line, cement can build up and harden, which leads to blockages and downtime.
Can a terminal handle both cement and slag in the same system? Yes, with the right design. Diverter valves, dedicated destinations and good cleanout practices make it possible to handle multiple products reliably.
How do I increase throughput at an existing terminal? Start by finding the bottleneck. It's often a single transfer line, a worn feeder, or an undersized air supply rather than the whole system.
Planning a terminal or expanding one?
Whether you're building a new import terminal, adding a rail-served distribution site, or trying to get more out of the lines you already have, our engineers can help you size the system for the distance and keep it running around the clock.
Call (800) 238-2974 or email info@deltaducon.com to talk through your project.
