River Pebble Crushing, Screening and Washing Line — 120–130 t/h

This stationary solution processes 0–180 mm river pebble at 120–130 t/h and produces four separate product streams: washed sand 0–6 mm, dry sand 0–6 mm, aggregate 6–12 mm and aggregate 12–20 mm. The line combines natural-fines scalping, jaw and cone crushing, closed-circuit screening and separate sand washing in one continuous process.

River pebble is typically hard and abrasive. For this reason, the main reduction stages use compression-type jaw and cone crushers. A 60 mm grizzly section on the feeder removes natural fines into a separate stream so the entire feed does not pass through the jaw crusher.

Production objective

The line is designed for operations that need washed sand, dry sand and two graded aggregate products from one feed stream. Its task is not only to reduce the pebble size, but also to control each final fraction, return oversize for further crushing and wash the natural 0–6 mm sand without mixing it with the other products.

Key design parameters

Feed material: River pebble

Feed size: 0–180 mm

Feed capacity: 120–130 t/h

Design material balance: Based on 130 t/h

Feeder grizzly opening: 60 mm

Final products: Washed sand 0–6 mm; dry sand 0–6 mm; aggregate 6–12 mm; aggregate 12–20 mm

Operating mode: Continuous; final duty confirmed to customer requirements

Why this configuration was selected

Natural-fines scalping. The feeder's 60 mm grizzly diverts 0–60 mm material around the jaw crusher. This avoids unnecessary crushing of material that is already fine and distributes the load across the downstream equipment.

Two-stage compression crushing for hard pebble. The 60–180 mm stream is reduced in a PEX-300×1300 jaw crusher and then enters the PSGD-1308 cone-crusher circuit. This sequence suits progressive reduction of hard, abrasive river pebble.

Closed-circuit top-size control. Material larger than 20 mm from the second screen returns to the cone crusher. Oversize therefore does not enter the finished-product stockpiles and is reprocessed until it reaches the required size.

Separate washed and dry sand streams. Natural 0–6 mm material from the first screen is sent to the spiral sand washer. The 0–6 mm material produced after cone crushing and final screening is discharged separately as dry sand.

Process flow

1. Receiving and controlled feeding. River pebble sized 0–180 mm enters the receiving hopper and is metered into the line by a vibrating feeder.

2. Scalping at 60 mm. The feeder grizzly divides the flow: approximately 65 t/h of 60–180 mm material goes to the jaw crusher, while approximately 65 t/h of 0–60 mm material goes to the first vibrating screen.

3. Jaw crushing. The PEX-300×1300 processes the 60–180 mm stream at a design CSS of 40 mm. The approximately 0–60 mm product enters the cone-crushing circuit.

4. Natural-sand separation. A 2YK1848 double-deck screen with 25 and 6 mm apertures separates approximately 50 t/h of natural 0–6 mm sand. The combined material above 6 mm, approximately 15 t/h, goes to the cone crusher.

5. Sand washing. The 0–6 mm stream from the first screen feeds an XL920×7.5 single-spiral sand washer. Water removes clay, dust and light impurities. The calculated washed-sand flow is approximately 50 t/h.

6. Cone crushing. Fresh feed to the PSGD-1308 short-head cone crusher is approximately 80 t/h: about 65 t/h from the jaw crusher and 15 t/h from the first screen. Including material larger than 20 mm returned from the second screen, the internal circuit load reaches approximately 138 t/h. The design CSS is 12–14 mm.

7. Final screening and recirculation. A 3YK1860 three-deck screen with 20, 12 and 6 mm apertures separates 0–6, 6–12 and 12–20 mm products. Material above 20 mm returns to the cone crusher.

8. Separate stockpiling. Conveyors form four individual stockpiles: washed sand 0–6 mm, dry sand 0–6 mm, aggregate 6–12 mm and aggregate 12–20 mm.

Main equipment

Vibrating feeder — 60 mm grizzly; final model confirmed during engineering. Function: uniform feeding and removal of the 0–60 mm stream.

Jaw crusher — PEX-300×1300; 55 kW; design CSS 40 mm. Function: reduce 60–180 mm feed to approximately 0–60 mm.

Vibrating screen No. 1 — 2YK1848; 25/6 mm apertures. Function: separate natural 0–6 mm sand and direct material above 6 mm to the cone circuit.

Spiral sand washer — XL920×7.5; single spiral. Function: wash natural 0–6 mm sand as a separate product.

Cone crusher — PSGD-1308; short-head chamber; 160 kW; CSS 12–14 mm. Function: secondary and fine crushing of hard river pebble.

Vibrating screen No. 2 — 3YK1860; 20/12/6 mm apertures. Function: final sizing and return of material above 20 mm to the closed circuit.

Belt conveyors — quantity, length and width according to the final layout. Function: interstage transport, recirculation and four separate product stockpiles.

MCC/PLC control cabinet — 380 V, 50 Hz, three-phase; final configuration after load calculation. Function: sequential starting, interlocks, motor protection and emergency stopping.

Calculated final-product output

Washed sand, 0–6 mm: approximately 50 t/h from the first screen and spiral sand washer.

Dry sand, 0–6 mm: approximately 18 t/h from the second vibrating screen.

Aggregate, 6–12 mm: approximately 30 t/h from the second vibrating screen.

Aggregate, 12–20 mm: approximately 32 t/h from the second vibrating screen.

These values are a calculated material balance for 130 t/h feed. Actual output depends on feed grading, moisture, natural sand and clay content, screening efficiency and the operating crusher settings.

Practical value

The line produces four separate streams while keeping natural washed sand separate from dry sand generated in the cone circuit. Scalping at 60 mm removes already fine material from unnecessary crushing. The closed circuit between the cone crusher and second screen returns particles above 20 mm for further processing and improves control of the final fractions.

Information required before final engineering

• Feed grading, moisture, clay content and washability.

• Local standards and laboratory requirements for the finished fractions.

• Site plan, elevations and finished-product stockpile positions.

• Conveyor quantity, length, belt width, inclination and drive power.

• Water source and required water quality, including settling or recirculation arrangements.

• Foundations, drainage, electrical supply and auxiliary systems.

Provide the Tanker engineering team with a feed sample or grading analysis, required hourly capacity, finished-product sizes, site plan, and water and power data. These inputs are used to finalize the layout, conveyors, foundation loads and control-system configuration.