Quick Start Guide
For Expo Visitors
Welcome to Mill Simulator
This simulator shows a cross-section of a real grinding mill - the kind Multotec designs liners for. Use the sliders on the right to change how the mill operates and watch the steel balls and slurry react in real time. Here's what each control does, in plain language:
Mill Speed (% Critical)
How fast the mill spins — the first control at the top of the panel. Below 65% the balls roll (cascading); 65–82% they fly (cataracting); above 82% they stick to the wall (centrifuging - bad for grinding). RPM is derived automatically from the diameter.
Mill Geometry
Shell Inner Diameter (1–12 m) sets the mill size. Rubber Lining (0/6/12 mm) is the wear layer inside the shell. Bigger mills spin slower in RPM for the same % critical speed.
Shell Plate
Shell Plate Left / Right Thickness (30–150 mm each) is the steel plate behind the rubber, set independently for the leading and trailing sides of each lifter so the plate top forms an angled ball-tumbling surface. Shell Plate Lip (10/15 mm) is the reduced thickness under each lifter, producing the stepped cross-section.
Lifter Bars
Bars on the inside of the shell that lift the balls. Set Height (50–400 mm), Leading Edge Height (30–165 mm), Width (100–400 mm), Face Angle (0–45°), and Count (6–60). The S:H guidance flags whether the spacing-to-height ratio is in the working band — target is aimed at mid-life per Malcolm Powell.
Charge Levels
Total Charge Level (0–45%) is media + ore combined. Grinding Media Level (0–45%, clamped to ≤ total) is the steel-ball portion; ore is the remainder. Media and Ore Over-seed (1–3×) pack the settled pile up to the target line.
Particle Size Distributions
Custom mixes of media ball and ore particle diameters, set as diameter/percentage rows totalling 100%. Media renders grey (steel); ore renders brown. Multiple sizes fill interstitial spaces for better grinding.
Friction
Four independent coefficients (0.05 slippery → 0.7 sticky): Media-to-Media, Media-to-Boundary, Ore-to-Ore, Ore-to-Boundary. Higher boundary friction drags the charge higher up the shell before it slips. Changes take effect live.
Reading the Output Indicators
Charge Motion: Cascading (green), Cataracting (amber), or Centrifuging (red) - based on speed, shown as a badge in the floating panel.
Charge Lines: Toggle Total (green), Media (orange), and Ore (light blue) to overlay each component's target free-surface chord.
Toe & Shoulder Markers: Blue block = toe (impact/landing side), orange block = shoulder (lift-off side) of the largest media.
Tracer Lines: Fading yellow paths follow the largest media balls from shoulder to toe, showing the cataracting trajectory (25–100% selectable).
Liner Damage Alerts: When a large ball hits the liner above 3.5 m/s, a red flash marks the point and the severity band is reported — Medium (3.5–4.5 m/s) or High (≥4.5 m/s).
Theoretical Trajectory: The Theory toggle overlays a red parabolic curve and impact square for the ideal single-particle flight from the lifter shoulder (MillTraj-style), plus theoretical shoulder/toe markers.
Mill Volume: The true free interior volume of a 1 m slice (excluding heads and liners), shown in the floating panel.
Derived Values & Counts: Effective diameter/radius, charge angle, critical speed, RPM, and per-size particle counts — all computed live.