Typical Slurry Density Ranges Reference
Broad, preliminary typical slurry density and percent-solids ranges by ore type and processing stage — iron ore, gold, copper, alumina, lithium, coal, and tailings/thickener/transport context. Educational ranges only, not site-specific design values.
Caution — preliminary orientation only
These are broad educational ranges for orientation, not a database of design values.
Slurry density and percent solids vary widely with the specific ore, mineralogy, grind size, rheology, flocculant, plant design, sampling point, and operating conditions. The ranges below are deliberately wide and are meant only to give a sense of scale. They are not site-specific, and they must never be used as design figures. Design work requires project testwork, plant samples, vendor data, and qualified engineering review.
Purpose
When you first sketch a slurry stream you often need a rough sense of what density or percent solids is plausible before any measurement exists. This reference gives broad ranges by ore type and processing stage so you can sanity-check an estimate or pick a starting value to feed into the Slurry Density Calculator. It is orientation, not authority — once you have a real number, use it.
Typical ranges by ore and stage
Percent solids (Cw) is by mass. Slurry SG is the bulk specific gravity of the slurry (density ÷ 1000). Ranges overlap heavily and are indicative only.
| Service / ore | Stage | Solids SG | % solids (Cw) | Slurry SG |
|---|---|---|---|---|
| Iron ore | Flotation / process feed | 4.5 – 5.3 | ~25 – 45% | ~1.2 – 1.5 |
| Iron ore | Thickener underflow | 4.5 – 5.3 | ~50 – 70% | ~1.6 – 2.4 |
| Iron ore tailings | Pipeline transport / deposited | ~3.0 – 4.5 | ~30 – 55% | ~1.3 – 1.9 |
| Gold (CIL / leach) | Leach / CIL feed | ~2.6 – 2.9 | ~40 – 50% | ~1.4 – 1.6 |
| Copper | Flotation feed | ~2.7 – 3.0 | ~25 – 40% | ~1.2 – 1.4 |
| Copper concentrate | Thickener underflow | ~4.0 – 4.3 | ~60 – 70% | ~1.8 – 2.2 |
| Alumina (Bayer) | Red mud / residue | ~2.9 – 3.5 | ~25 – 50% | ~1.2 – 1.7 |
| Lithium (spodumene) | Process / flotation feed | ~2.6 – 3.2 | ~25 – 40% | ~1.2 – 1.4 |
| Coal | Coarse / fine slurry | ~1.3 – 1.8 | ~30 – 60% | ~1.1 – 1.4 |
| General tailings | Thickener underflow / transport | ~2.6 – 3.0 | ~40 – 65% | ~1.3 – 1.9 |
Iron ore tailings has a dedicated page with more context — see the Iron Ore Tailings Slurry Density Reference.
Units
- •Solids SG and slurry SG — dimensionless specific gravity (density relative to water at ~1000 kg/m³).
- •% solids (Cw) — percent solids by mass: mass of solids ÷ total slurry mass.
- •To work in kg/m³, multiply SG by 1000 (SG 1.5 ≈ 1500 kg/m³). Convert with kg/m³ → lb/ft³.
Assumptions
- •Two-phase mixtures of mineral solids in a water-based liquor at ambient conditions.
- •Liquor density near water (1000 kg/m³) unless heavily loaded with dissolved species.
- •Ranges reflect common operating practice across many sites — not any single operation.
Boundaries and exclusions
- •Educational ranges only — not site-specific, not design values, not a certified database.
- •Does not capture mineralogy, grind size, rheology, flocculant, or plant-specific practice.
- •Does not model settling, segregation, yield stress, or pumpability.
- •Ranges overlap and are indicative; real values commonly fall outside them.
How to use in calculations
Pick a plausible solids SG and percent solids for your ore and stage, then enter them into the Slurry Density Calculator to get a slurry density, or into the Percent Solids Mass ↔ Volume Calculator to convert between the mass and volume bases. Use the result only as a preliminary estimate and replace it with measured plant data as soon as it exists. For a stream split into solids and liquid flows, use the Slurry Mass Balance Calculator.
Source / context notes
- •General mineral-processing and slurry-handling practice (e.g. Wills' Mineral Processing Technology; slurry transport references such as Wilson, Addie, Sellgren & Clift).
- •Solids SG figures follow common mineral densities (quartz ~2.65, hematite ~5.2, magnetite ~5.1, coal ~1.3–1.8).
Ranges are compiled for orientation only. For any real calculation, use measured plant samples, project testwork, and vendor data reviewed by a qualified engineer.