MingShen Science WZ-50 Benchtop Sample Mill

Overview

The MingShen Science WZ-50 Benchtop Sample Mill is a compact, high-efficiency mechanical grinding instrument engineered for standardized sample preparation in coal analysis laboratories. It operates on the principle of impact and shear comminution, utilizing a rotating hardened steel rotor and fixed grinding chamber to reduce heterogeneous solid materials—particularly brittle, low-moisture coal and rock samples—to a consistent, analytically suitable particle size distribution. Designed in strict accordance with the dimensional, operational, and performance requirements of GB/T 474–2008 “Method for Preparation of Coal Samples”, the WZ-50 ensures representative sub-sampling by minimizing segregation and thermal degradation during short-duration grinding cycles. Its benchtop footprint (approx. 360 × 280 × 420 mm), 220 V AC input compatibility, and absence of external cooling or compressed air dependencies make it suitable for deployment in routine QC labs, field mobile laboratories, and teaching environments where space, power infrastructure, and operational simplicity are constrained.

Key Features

• Compact, self-contained architecture optimized for laboratory benchtop use without auxiliary utilities
• 550 W high-torque induction motor delivering stable rotational speed under variable load conditions
• Hardened steel grinding chamber and rotor assembly engineered for wear resistance and long-term dimensional stability
• Adjustable retention time via manual start/stop control; optional timer module available upon request for GLP-aligned process repeatability
• Acoustic enclosure design reducing operational noise to ≤72 dB(A) at 1 m distance
• Interlocked safety lid with mechanical cut-off switch preventing operation when open
• Tool-free disassembly of grinding chamber for rapid cleaning and cross-contamination prevention between batches

Sample Compatibility & Compliance

The WZ-50 is validated for hard, dry, non-fibrous, non-sticky solid samples with Mohs hardness ≤6 and moisture content <5%. Typical applications include bituminous coal, anthracite, lignite, shale, limestone, and ceramic raw materials. It is not intended for soft polymers, fibrous biomass, wet slurries, or temperature-sensitive pharmaceutical actives. All mechanical and electrical components conform to IEC 61000-6-3 (EMC emission limits) and IEC 61000-6-2 (immunity). Performance verification against GB/T 474 includes assessment of particle size uniformity (via sieve analysis per ISO 3310-1), batch-to-batch reproducibility (RSD ≤3.2% for 10 consecutive 50 g coal replicates), and absence of metal contamination (verified by ICP-MS trace elemental screening of ground product).

Software & Data Management

As a manually operated mechanical mill, the base WZ-50 model does not incorporate embedded software or digital interfaces. However, its operational parameters—including batch ID, feed mass, grinding duration, and sieve verification results—are fully compatible with laboratory information management systems (LIMS) and electronic lab notebooks (ELN) when recorded using standardized SOP templates. For users requiring audit-trail capability under GLP or GMP frameworks, the optional timer module supports timestamped start/stop logging, which can be exported as CSV for integration into 21 CFR Part 11-compliant data repositories. Calibration records, maintenance logs, and GB/T 474 verification reports are provided in bilingual (English/Chinese) PDF format with each unit shipment.

Applications

• Routine preparation of coal samples for proximate analysis (moisture, ash, volatile matter, fixed carbon) per ASTM D3172 and ISO 1171
• Generation of homogenized reference material subsamples for inter-laboratory proficiency testing
• Pre-grinding step prior to X-ray fluorescence (XRF) or inductively coupled plasma (ICP) digestion protocols
• Particle size reduction of geological core fragments for petrographic thin-section preparation
• Teaching demonstrations of mechanical size reduction principles in undergraduate materials science curricula

FAQ

Is the WZ-50 compliant with international coal testing standards beyond GB/T 474?
Yes—the device meets the functional equivalency criteria of ASTM D2013 and ISO 13909-3 for sample division and size reduction, provided feed material complies with specified moisture and hardness limits.
Can the WZ-50 be used for food or pharmaceutical samples?
No. It is not constructed to meet FDA 21 CFR Part 117 (food) or ICH Q5C (pharmaceutical) material contact requirements. Stainless steel surfaces are unpolished and lack certification for hygienic processing.
What maintenance is required for long-term reliability?
Monthly inspection of rotor balance and chamber liner wear; biannual lubrication of motor bearings per ISO 12100; replacement of grinding chamber liners recommended after ≥500 operating hours or visible pitting.
Does the unit include calibration documentation?
Yes—a factory-verified GB/T 474 conformance report, including sieve analysis data for three independent coal lots, is supplied with each shipment.
Is technical support available in English for international customers?
Yes. Remote troubleshooting, SOP development assistance, and application-specific validation guidance are provided by MingShen Science’s international technical service team via email and video call.