IKA MultiDrive MI 250.3 hammer, tungsten carbide, 0020023168

Solid-state physics and tribological resistance

In geochemical analysis, metallurgy and materials testing, the comminution of extremely hard, mineral or ceramic sample matrices reaches fundamental physical limits. Standard stainless steel grinding tools suffer severe tribological deformation and extreme material wear when used on matrices with a Mohs hardness of over 6. The IKA MultiDrive MI 250.3 beater is made entirely of tungsten carbide (WC). This intermetallic hard metal compound is characterised by extreme structural density and a hardness reaching values of up to 9.5 on the Mohs scale (just below diamond). This material superiority makes the tool completely immune to plastic deformation caused by abrasive micro-collisions with hard ores, quartzites, glasses or slags.

Kinetics of extreme impact crushing

The physical principle of comminution remains identical to that of a standard impact crusher: driven at up to 30,000 revolutions per minute by the MultiDrive system, the MI 250.3 transforms rotational energy into massive kinetic impact energy. Due to the extreme hardness and very high specific gravity of tungsten carbide, the mechanical impulse transferred to the sample material upon impact is significantly more rigid and results in less energy loss than with more elastic steel alloys. The lattice structures of even extremely brittle, crystalline solids are shattered by the incoming shock waves in fractions of a millisecond and converted into a highly fine, analytically usable powder matrix.

Analytical purity and iron-free grinding

A key problem in trace element analysis (for example, using ICP-OES or XRF) is sample contamination caused by abrasion of the grinding tool (carry-over). Grinding hard rocks with stainless steel tools inevitably leads to a massive introduction of iron, chromium and nickel ions, which distorts or renders impossible the quantitative elemental analysis of these metals in the sample. The use of the MI 250.3 tungsten carbide beater physically eliminates this specific heavy-metal contamination entirely. The sample material is only minimally doped with tungsten and carbon, which is metrologically irrelevant for most iron-focused geological or metallurgical analyses.

Technical details

• Product type: Hammer for extreme impact crushing (interchangeable tool)
• Material: Tungsten carbide (hard metal)
• Processing principle: Impact and percussion comminution (impact milling)
• Physical scope of application: Extremely hard and brittle matrices (ores, glass, ceramics)
• Hardness of the material: approx. 9 to 9.5 on the Mohs scale
• Analytical advantage: Prevention of iron, chromium and nickel contamination
• Compatibility (vessel): Exclusively suitable for the IKA MultiDrive MI 250 grinding chamber
• Compatibility (drive): IKA MultiDrive basic and MultiDrive control
• Fitting: Tool-free, form-fit replacement in the grinding vessel

Contents

• 1 x IKA MultiDrive MI 250.3 beater (tungsten carbide)

(Important note: The MultiDrive drive unit and the MI 250 grinding chamber are not included in the scope of delivery!)

Customised requirements & accessories

The MI 250.3 beater is the ultimate high-end solution for the hardest materials. To consistently maintain the analytical integrity of the system during iron-free grinding, it is essential that not only the beater but also the grinding chamber itself does not cause any iron contamination. Although tungsten carbide is extremely hard, its crystalline structure makes it more susceptible to bending or lever forces than ductile stainless steel. The tool must never be forced into the vessel at an angle. Please contact our procurement service at any time for the metrologically correct configuration of your milling systems.