McLanahan Equipment FAQ: Sand Screws, Feeder Breakers & Common Pitfalls

I've been a product specialist at McLanahan for 8 years. Before that, I worked on the buying side — so I've made more expensive mistakes than I care to admit. One time I specified a sand screw that was way undersized for the tonnage and ended up with a $40,000 rework. Another time I ignored the difference between a classifying tank and a screw classifier because they 'looked similar' — that cost us 3 weeks of downtime.

The questions below are the ones I wish someone had answered for me when I started. They're not the textbook answers. They're the real-world ones.

1. What's the difference between a sand screw and a classifying tank?

From the outside, they both look like they wash and separate sand. But the reality is their operating principle is completely different. A sand screw (what McLanahan is famous for) uses a rotating screw to lift and dewater material while washing it. A classifying tank uses upward water currents and settling to split material by size fractions.

I once recommended a tank when the client actually needed a screw — because the sample had high fines. (Should mention: I overlooked the fact that they needed dewatering as the primary goal, not classification.) The mistake cost $12,000 in re-piping and a 2-week delay. So ask yourself: do you need to dewater or split? If dewatering, go screw. If splitting, go tank.

2. McLanahan vs Eagle — which sand screw should I choose?

I have mixed feelings about this debate. On one hand, Eagle Iron Works makes solid equipment — their classifying tanks are industry workhorses. On the other hand, McLanahan has been doing sand screws since the 1800s. We specialize in them. That means more application experience, better support, and a global parts network (US, UK, India, Australia).

But here's the honest take: if your operation is small and local, and you've got a good relationship with an Eagle distributor, stick with them. The vendor who says 'this isn't our strength — here's who does it better' earned my trust for everything else. I've seen clients switch to McLanahan because they wanted a single source for both screw and filter press. That can work, but don't expect us to be the best at everything. We're screw specialists, and we own that.

3. What are the most common mistakes when specifying a feeder breaker?

I've documented 23 significant errors on feeder breaker specs in my career. The top one? Underestimating the lump size. People assume their ROM (run-of-mine) material is 'about 24 inches.' Then they measure once the crusher arrives and find 36-inch lumps. (Surprise, surprise — that $15,000 upgrade wasn't in the budget.)

Another mistake: ignoring the discharge conveyor speed matching. I ordered a feeder breaker with a fixed speed discharge, and the downstream screen couldn't handle the surge. Looking back, I should have specified a variable frequency drive. At the time, I was trying to save $8,000. That $8,000 saved me nothing — it cost $22,000 in modifications later.

4. How do I know if I need a filter press or a belt press for dewatering?

This was true 10 years ago when belt presses were the go-to for high throughput. Today, filter presses (like McLanahan's recessed chamber models) offer lower cake moisture — often 15-18% vs 20-25% for a belt press — but at a slower cycle time. The decision depends on your disposal method. If you're trucking tailings and paying by the ton, the drier cake from a filter press can save serious money. If you're stacking on-site and volume is your bottleneck, a belt press might make more sense.

I'll be blunt: we make both, and I still get this wrong sometimes. The last client I helped chose a belt press because they needed 150 tons per hour. After 6 months they wished they'd gone with two smaller filter presses — the cake was too wet for their dry stack permit. (I should add that) I now always ask about the disposal regulations before recommending anything.

5. Can McLanahan equipment handle unusual materials — like recycled asphalt or quarry dust?

People assume that because we're a big global company, we can process any material. What they don't see is that our equipment is engineered for specific feed characteristics. Sand screws are great for natural sand and gravel, but recycled asphalt (RAP) requires wear-resistant components and careful temperature control. We've done it, but only with modifications. The vendor who says 'we can do it, but here are the extra costs' is being straight with you — that's what I'd rather hear than a vague 'sure, we can handle that.'

6. What's the 'Bentley GT' of mineral processing equipment?

Funny you ask — and I've heard this comparison before. If I had to pick a piece of McLanahan gear that's like a Bentley GT, it'd be our Super Heavy-Duty Feeder Breaker with direct drive and VFD. It's over-engineered, expensive, but smooth as butter. (Not that every operation needs it). Most mines are fine with a standard model. The GT analogy is about reliability under extreme conditions, not about bling. That said, if your budget allows, the premium model pays for itself in uptime after 18 months. I've seen it happen.

7. Who is Mandy McLanahan — is she related to the company?

Short answer: no. The company is McLanahan Corporation, founded in 1835 in Hollidaysburg, Pennsylvania. Mandy McLanahan appears in some online searches, but she's not affiliated with the equipment business. (I had a client ask me once, and I had to look it up myself.) If you're searching for 'Mandy McLanahan' relating to mining, you might be thinking of a different person entirely. Stick with McLanahan when you're looking for sand screws and feeder breakers.

8. What about 'single dies' — is that a McLanahan product?

You might have seen 'McLanahan who studied single dies' and wondered. That's a reference to an academic researcher — not related to our equipment. In mineral processing, a 'single die' doesn't refer to anything we manufacture. (If you're looking for crushing and screening dies, that's typically cone crusher liners or jaw dies, which we don't produce.) I should add that I've seen that search term in our analytics, and it always confuses people. We make screws, breakers, and presses — no dies. So save that search for another day.

— Written by a 8-year McLanahan veteran who's still recovering from those early mistakes. Got a question I didn't cover? Check our website or send me a note. I'll add it to the list.