A vertical shaft impactor makes sand by throwing rock at rock at 60–80 m/s rather than squeezing it. That matters because it is the only common crusher that improves particle shape: the resulting sand is cubical with a controlled fines curve rather than the flaky, elongated material a cone produces at the same size.
For concrete-grade manufactured sand, shape and gradation are not cosmetic. Flaky sand needs more cement and more water to reach the same workability, which is a permanent cost on the buyer's side, forever. That is the argument we make to clients comparing a VSI against a cheaper cone-based sand solution — and it is measurable per cubic metre of concrete.
Typical duty: final stage in manufactured-sand lines, shaping stage after a cone in aggregate plants, and fine crushing in metal-ore circuits. Wet and dry process arrangements are both available, including the rainy-season wet process we run at our own 500 t/h Hangzhou project.
Product and workshop photographs from our own production lines — Hangzhou, Weihai and Wuhu.
Design & working principle
- Rock-on-rock and rock-on-anvil configurations — rock-on-rock gives better shape and lower wear cost; rock-on-anvil suits harder, more abrasive feed.
- Twin-motor drive with balanced load — two motors, 200×2 to 355×2 kW, giving redundancy and smoother starting on weak supplies.
- Hydraulic lid opening — impeller and anvil access without a crane, which is what makes the weekly wear inspection realistic on a working site.
- Cascade feed option — a second feed stream to the rotor, used to increase tonnage and fine-tune the gradation curve without changing speed.
- Bearing temperature monitoring — the interlock that stops the machine before a $30 bearing becomes a $30,000 shaft.
Parameter table
Published as a real HTML table, not a PDF or an image — so it can be read, copied and indexed. Figures are from our own product documentation; the datasheet and GA drawing follow on request.
| Model | Max feed size (mm) | Power (kW) | Impeller speed (r/min) | Capacity (t/h) | Dimensions L×W×H (mm) |
|---|---|---|---|---|---|
| SJ.L.400 | 40 | 200×2 | 1,200–1,400 | 220–450 | 5,600×2,700×3,700 |
| SJ.L.450 | 45 | 220×2 | 1,200–1,400 | 270–500 | 5,600×2,700×3,700 |
| SJ.L.500 | 45 | 250×2 | 1,200–1,400 | 300–550 | 5,600×2,700×3,700 |
| SJ.L.560 | 45 | 280×2 | 1,200–1,400 | 350–550 | 5,600×2,700×3,700 |
| SJ.L.630 | 45 | 315×2 | 1,200–1,400 | 380–600 | 5,600×2,700×3,700 |
| SJ.L.710 | 50 | 355×2 | 1,200–1,400 | 450–700 | 5,600×2,700×3,700 |
Capacity shown is total through the machine. Sand output (0–5 mm) depends on feed gradation, rotor speed and closed-circuit screening: typically 35–55% of the figure above in a closed-circuit sand line.
Configuration & options
Crushing configuration
Rock-on-rock (better shape, lower wear cost) or rock-on-anvil (harder, more abrasive feed). We will recommend one from your rock type.
Cascade feed
Second feed stream to the rotor for tonnage and gradation control.
Wet or dry process
Dry process with bag filter, or wet process with water injection and dewatering screens for rainy-season production.
Sand washing
Wheel or screw sand washers and dewatering screens to reach your target fines and silt content.
Twin drives
Soft-start or VFD for genset and weak-grid sites; both motors independently protected.
How to choose the right model
- Decide the process first: dry or wet. In West Africa and Southeast Asia, a rainy season with high feed moisture is the single most common reason a sand line underperforms in months 4–8 of operation. Plan for it before ordering.
- Then decide rock-on-rock versus rock-on-anvil from your rock's abrasiveness. Basalt and river gravel wear anvils fast; granite is more forgiving.
- Finally, size for sand output rather than total throughput — a 500 t/h VSI in closed circuit does not produce 500 t/h of sand, and any supplier quoting it that way is quoting a number you will never see on a belt scale.
Delivery & service commitments
| Item | Commitment |
|---|---|
| Standard machine lead time | 60 days from order confirmation |
| Annual production capacity / monthly shipments | 1,000 units per year · 100 units per month (all ranges) |
| Spare parts supply | Within 2 months worst case; typically far faster for models in current production |
| Engineer attendance on site | Within 10 days of the requirement being agreed, for export markets |
| Remote support | Response within one working day; included, not charged |
| Warranty | Terms stated in the contract in the same words published on this site |
| Installation & commissioning | Guidance and supervision by our engineers, through to acceptance at rated capacity |
| Buyer provides | Site civil works, electrical installation and site access — drawings and answers supplied |
We supply the machines, the drawings, the commissioning support and the parts. We do not operate your plant after handover.
Common questions
What is the difference between a VSI and a cone sand maker?
A cone sand maker compresses rock, so it produces a higher proportion of flaky particles; it is cheaper to buy and cheaper per ton to run. A VSI breaks rock by impact, so the particles come out cubical. For concrete and asphalt specification work the VSI result is usually the only one that passes, and the extra cement saved pays back the difference. We build both and will tell you which your market's spec allows.
Can I produce both sand and aggregate on the same line?
Yes, and most of our clients do: crushing and screening produce the aggregate sizes, and a VSI in closed circuit with a sand screen produces 0–5 mm. The configuration sheet shows exactly what goes where — see the plant-design page.
What is the wear cost per ton?
It depends entirely on your rock's abrasiveness and on the crushing configuration. We will give you a per-ton wear estimate based on your rock type and the feed gradation, and we quote wear parts per set rather than per piece so the number is comparable.