Laboratory Jaw Crusher

What is the Laboratory Jaw Crusher?

A laboratory jaw crusher reduces lump coal from about 50 to 100 mm down to a few millimetres, preparing it for further size reduction. Jaw gap setting and jaw plate material govern product size and contamination risk.

Overview

Two jaws, one fixed and one driven by an eccentric shaft, crush material in the V-shaped opening. Product size is set by adjusting the gap between the lower ends of the jaws, typically from 2 to 20 mm, and a discharge chute directs material to a collecting tray or the next stage. Laboratory models accept feed openings from about 60 to 200 mm and process 100 to 500 kg per hour, which suits batch preparation rather than production sampling. Jaw plates are usually manganese steel for durability or tungsten carbide for low iron pick-up. Enclosed designs with dust-extraction connections are important for coal, because fine dust is lost and moisture changes if the crusher is open. Material must be fed at a steady rate, since overfeeding causes the jaws to stall and increases wear.

How does it work?

Coal is heterogeneous, so sample preparation must cut particle size and sample mass without changing composition. Size reduction proceeds in stages: a jaw or roll crusher takes lump coal down to a few millimetres, a hammer mill or crusher reduces it to about one millimetre, and a vibratory ring mill or disc pulverizer grinds a laboratory portion below 200 µm, or to 75 µm for ash and elemental work. Between stages the sample must be mixed and divided, because mass reduction must be proportional: a riffle divider splits a stream into two equal halves through alternate chutes, and a rotary divider collects a controlled stream in rotating vessels to give identical fractions. Moisture control is critical, so equipment is enclosed, pass-through times are short and contact surfaces are chosen to avoid adding iron or other contamination that would bias ash and elemental results.

What are the key features?

• Adjustable jaw gap for product size control
• Feed opening from about 60 to 200 mm
• Replaceable manganese steel or tungsten carbide jaw plates
• Enclosed chamber with dust extraction connection
• Collecting tray or chute for continuous discharge
• Overload protection through belt drive or clutch

What are the technical specifications?

A typical laboratory jaw crusher configuration offers feed opening of 100 × 60 mm to 200 × 150 mm, maximum feed size of 50–100 mm, product size of 2–20 mm adjustable, throughput of 100–500 kg/h, jaw plate material of Manganese steel or tungsten carbide and motor power of 1.5–4 kW. Values are indicative of the product class; the exact figures for each configuration are confirmed on the quotation and the calibration documents supplied with the instrument.

Which applications is it used for?

The Laboratory Jaw Crusher is used in first-stage crushing of coal lumps, preparation of coke and biofuel samples, reduction of drill core and channel samples and mine and plant sample rooms. Across the wider Coal Sample Preparation class, laboratories also deploy it for coal mine and preparation plant sample chains, power station coal quality laboratories and commercial inspection sample preparation.

Which standards and certifications apply?

Relevant standards and methods include ASTM D2013, ASTM D2234, ISO 1988, ISO 13909-1, ISO 18283, GB/T 474, GB/T 475 and IEC 61010-1. Certification candidates for this model are CE and ISO 9001 manufacturing; each is to be confirmed for the specific configuration before shipment, and certificates are supplied only where they have been issued.

Prepare samples in a controlled room where moisture loss is limited, and work quickly through each stage, weighing after every division so that mass balance can be checked. Clean equipment between samples with brushes and, where necessary, by running a small amount of the next sample through, to avoid cross-contamination. Record the top size, mass and equipment settings for each stage so the reduction history can be audited. Keep grinding sets within wear limits, since worn plates change product size and can raise ash through iron pick-up. Guard feed openings, provide dust extraction rated for coal dust and use motors and switches suitable for a dusty environment. Reference materials and duplicate samples should be put through the same chain as routine samples to verify that no bias is introduced.

How do I select the right Laboratory Jaw Crusher?

Select the jaw crusher as the first stage, matching the feed opening to your largest lumps and the gap range to the next machine's feed. Specify jaw material according to how strictly iron contamination must be avoided, and include dust extraction and a stable power supply.

How does it compare with other Coal Sample Preparation variants?

Plan the whole chain before buying individual machines. Match the top size of incoming material to crusher feed openings and the required final fineness to the pulverizer, and keep reduction ratios moderate by using several stages rather than one large step. Check throughput against the number of samples per shift, and check that the product size table of the sampling standard is respected, since the minimum sample mass depends on top size. Choose contact materials with contamination in mind: manganese steel wears well but adds iron, while tungsten carbide or ceramic grinding sets cost more and keep ash and trace element results cleaner. Look for enclosed, dust-tight designs with extraction connections, quick-release bowls or plates for cleaning, and drives rated for continuous duty. For dividing, riffle dividers suit gravity flows and rotary dividers give the best precision on fine coal.