Primary Crushing of Hard and Brittle Samples with Vector Jaw Crushers

Rock cores, ore lumps, slag, and cement clinker are too large for a mill. Before XRF, XRD, or particle size analysis they go through a primary crushing step, and the quality of that step decides how representative everything downstream will be. This note covers the practical settings for the two Vector laboratory jaw crushers, the Nysos and the Thor.

Typical next steps are ball or disc milling, sieving, and XRF pellet pressing. The full jaw crusher family page lists specifications and accessories.

How a jaw crusher works

The sample is crushed in a wedge-shaped chamber between a fixed jaw and a moving jaw driven by an eccentric shaft. The moving jaw pushes material down toward the discharge gap. Once a fragment is smaller than the gap, it falls into the collector. The gap setting therefore controls the top size of the product.

Choosing between Nysos and Thor

	Nysos	Thor
Jaw size	100 × 250 mm	270 × 90 mm
Maximum feed size	90 mm	110 mm
Gap	Stepless 0–30 mm	Stepless 0–30 mm
Finest product	About 1 mm (material dependent)	About 1 mm (material dependent)
Throughput	Up to about 300 kg/h	150–300 kg/h
Drive	2.2 kW	7.5 kW
Jaw materials	Manganese steel, stainless steel, tungsten carbide	Hardened manganese steel
Operation	Gap scale with zero-point adjustment, dust extraction port	7″ touchscreen with stored profiles, jam detection and automatic reverse, optional sample splitter

Both crushers handle materials up to Mohs hardness 8. Throughput figures depend on the material and the gap; use them for planning, not as a guarantee.

Choose the Nysos when you need a choice of jaw materials for contamination control. Choose the Thor for larger lumps, continuous shift work, and when you want the crusher to clear jams by itself.

Crushing procedure

1. Dry the sample. Wet or clayey material packs into the chamber and smears on the jaws. Dry it first, for example in a drying oven at 105 °C.
2. Check the feed size. Lumps larger than the maximum feed size bridge in the chamber, polish the jaw faces, and stall the motor. Break them by hand first.
3. Set the gap. Set the discharge gap for the target top size. For a two-stage reduction, crush once at a wide gap, then pass the product again at the final gap.
4. Feed at a steady rate. Do not fill the chamber in one go. On the Thor, watch the motor load on the touchscreen; on the Nysos, listen for the drive slowing down.
5. Clean between samples. Empty the collector, brush the chamber, and blow it out with compressed air before the next sample.

Jaw material and contamination

Every jaw material leaves traces of itself in the sample. Pick the one whose elements are not in your analytical scope.

• Manganese steel: the standard choice for rock, concrete, and ore. Adds iron and manganese.
• Stainless steel: adds iron, chromium, and nickel. Useful when manganese must stay low; it is not an iron-free option.
• Tungsten carbide: the most wear-resistant choice for very hard and abrasive material. Adds tungsten and cobalt, so avoid it when those elements are analysed.

Run one sacrificial pass of the new material before the real sample when switching between very different materials.

Keeping the zero point accurate

Jaw faces wear over time, so a gap reading of 2 mm slowly stops meaning 2 mm. Check the zero point regularly, more often after long runs on abrasive material such as basalt or iron ore:

1. Stop the crusher and isolate it from power.
2. Close the gap until the moving jaw just touches the fixed jaw.
3. Reset the gap scale to zero.

Summary

Use the Nysos when jaw material choice matters and the Thor for large lumps and continuous work. Dry the sample, respect the feed size, choose the jaw material by what you will analyse, and keep the zero point checked.