Project Overview & Market Context
Guatemala is experiencing rapid infrastructure growth, with the construction aggregate market projected to grow at over 5% annually through 2030. River pebble — abundant in the country's river systems — has become a preferred raw material for manufactured sand production, offering high hardness (150–200 MPa), low impurity content, and excellent concrete bonding properties.
Core challenge:
The customer's existing mobile jaw crusher was producing crushed river pebble aggregate, but without proper screening classification and washing, the output suffered from three critical issues:
1. Uncontrolled particle gradation — crushed material remained unclassified, limiting its commercial value to low-grade fill applications.
2. Excessive silt and clay content — river pebble naturally carries surface sediment that must be removed through washing to meet concrete sand standards.
3. Single-product limitation — the jaw crusher alone could not produce multi-grade aggregates simultaneously for different market segments.
To upgrade the line into a full-featured sand and aggregate plant, the customer turned to Baichy Heavy Industry for a screening and washing expansion — 4 × 4YK1860 vibrating screens paired with spiral sand washers — achieving classified, washed, and commercially ready products in a single integrated system.
Baichy Heavy Industry's Equipment Selection Logic
This configuration employs a "4-screen vibrating screening → spiral washing" process, designed specifically as a retrofit to the existing mobile jaw crusher line. The logic: the jaw crusher handles primary crushing; the 4YK1860 vibrating screens take over classification; the spiral washers remove silt and clay — transforming raw crushed stone into graded, clean, market-ready aggregates and sand.
1. 4YK1860 Vibrating Screen — Four-Deck Precision Classification
The 4YK1860 is a four-deck circular vibrating screen with a screen box size of 1,800 × 6,000 mm. Four screens operating in parallel provide high throughput with multi-grade separation at a single pass.
| Parameter |
Value |
| Screen model |
4YK1860 (4-deck circular vibrating screen) |
| Screen box dimensions |
1,800 × 6,000 mm (width × length) |
| Screen area per deck |
10.8 m² |
| Number of decks |
4 (simultaneous 5-product classification) |
2. Spiral Sand Washer — Clean Sand Production
The 0–5 mm fraction from the bottom deck of each 4YK1860 passes directly into the spiral sand washer, where high-speed spiral blades agitate, scrub, and wash away silt, clay, and organic impurities.
| Parameter |
Value |
| Washer type |
Spiral sand washer (single / double spiral, configured per throughput) |
| Feed material |
0–5 mm screened sand (from 4YK1860 bottom deck) |
| Processing capacity (per unit) |
Matched to screen undersize output |
| Spiral diameter |
Configured to capacity (e.g., 750–1,200 mm) |
| Washing principle |
Counter-current spiral agitation + water injection |
| Impurity removal |
Silt, clay, organic matter, fine dust (<0.075 mm overflow) |
Screening + washing integration: The bottom-deck undersize (0–5 mm) from the 4YK1860 flows by gravity to the spiral washer, eliminating the need for intermediate conveyors or stockpiling. The washed sand exits with a silt content of ≤3%, comfortably within the ASTM C33 / GB/T 14684 limit of ≤5% for concrete sand.
