Frequently Asked Questions | Chema Engineers

What is the average wear life of polyurethane screen panels compared to wire mesh +

Polyurethane screen panels typically last **5 to 8 times longer** than traditional woven steel wire mesh. The exact ratio depends on aggregate abrasiveness and feed moisture. Polyurethane is an elastomer with high elastic memory. Under impact from heavy rocks, it deflects the load and absorbs energy, resisting surface wear. In contrast, rigid steel wires gradually wear thin and snap under repeated impact.

Should I choose high-chrome alloy or natural rubber impellers for my slurry pump +

The choice depends on feed particle size:

Molded Natural Rubber: Best for fine sand and slurry below 5mm. Rubber deflates fine particles without scratching. However, coarse stones or tramp metal will cut and destroy rubber quickly.
High-Chrome Metal Alloy (27% Cr): Required if your slurry feed contains larger aggregate particles (over 8mm) or sharp gravel, which would tear soft rubber casing liners.

How does a hydrocyclone sand wash plant prevent fine sand loss compared to bucket washers +

Traditional rotary bucket sand washers wash away clay by letting water overflow from the tub. However, this overflow water sweeps away a massive amount of fine sand (under 150 microns), which ends up in settling ponds.

A hydrocyclone sand wash plant (like the Chem-Wash) feeds slurry into a centrifugal chamber. Heavy sand grains are forced outward and exit at the bottom (underflow), while light silts and clay particles remain suspended in the center vortex and exit from the top (overflow). The underflow sand is dropped onto a high-frequency polyurethane dewatering screen, recovering **95%+ of fine sand down to 75 microns (200 mesh)**.

What flocculants and chemicals are recommended for sand washer water recovery +

We supply high molecular weight **polyacrylamide (Pam) flocculant powders** and liquid chemicals for water recycling. Typically, sand wash overflows containing silica or clay silts require **anionic flocculants** to settle negative surface charge silica particles. For clay-heavy slurries, a combination of a cationic coagulant (to neutralize charge) and an anionic flocculant (to form massive floc groups) is used. This allows clean water to settle and clarify in under 30 seconds for immediate reuse in the wash plant.

Can you manufacture custom-sized polyurethane screen panels or replacement parts +

Yes, Chema Engineers specializes in customized cast polyurethane components. We can manufacture screen panels, flip-flow mats, scrapers, casters, and hydrocyclone linings matching your exact drawings or OEM dimensions. Our engineering facility in MIDC Satara operates CNC machining and tooling bays to rapidly build custom molds for unique client requirements.

Where is Chema Engineers located and how can I order replacement parts +

Our registered office and main manufacturing factory is located at **P. No. L-16, Add. MIDC, Satara - 415004, Maharashtra, India**. We also have a sales and logistics branch at **Gala No. 004, Kalher Riddhi Siddhi Galaxy, Bhiwandi - 421302, Maharashtra** for fast distribution.

To order, you can submit an inquiry through our Contact page, email us at **sales@chemaengineers.com**, or chat directly with our sales team via WhatsApp at **+91 7387898936**.