Chromite ore specific weight: density and weight of 1 m³
Chromite ores, also called chromites or chrome spinels, are minerals containing chromium in different proportions. Many natural chromium compounds are known, but only those with chromium content sufficient for profitable mining and processing are considered chromite ores. Industrial-scale accumulations of chromium ores are also called chrome spinels.
Depending on composition, the following are distinguished:
- chromite itself, rarely found in nature in pure form, FeCr2O4, chromium content over 46%;
- alumochromite Fe(Cr, Al)2O4, chromium content over 37%;
- magnochromite (Mg, Fe)Cr2O4, over 42%;
- chrompicotite (Mg, Fe)(Cr, Al)2O4, over 33%.
The chemical composition of the above groups is heterogeneous, and the Cr2O3 content in them can vary greatly. Therefore, depending on the percentage content of this compound, chromite ores are divided into types, or grades:
- less than 40%;
- 40-45%;
- 45-50%;
- more than 50%.
Specific weight of chromite ores
The density of chromite ores depends on composition and grade. For low-grade ores, the approximate value may be within 3.8-4.0 g/cm3, and for high-grade ores about 4.3-4.6 g/cm3. The density of some chrome spinels can reach 5 or more g/cm3.
Use: extraction of chromium for manufacturing chemicals, paints and for the ferroalloy industry.
Chromite
A chromium-bearing rock mineral of iron-black color with brown shades. It has metallic luster and weak magnetic properties.
The rock is of magmatic origin and occurs with serpentinite and other ferruginous silicates. Large accumulations of chromites are very profitable to develop. Such deposits exist in South Africa, Kazakhstan, India and other countries.
Density is 4.5-4.8 g/cm3. Hardness is 5.5.
Alumochromite
A black chromium-bearing mineral of granular structure; in thin fragments it shows a red tint. It belongs to oxides and contains ferrous oxides, manganese, aluminum oxide, iron, nickel, titanium, vanadium and some other elements. The mineral has a metallic greasy luster, uneven fracture and brown streak.
The specific weight of alumochromite is 4.5-4.8 g/cm3. Hardness is 5.8-6.
Chrompicotite
A brownish-black mineral of granular, less often crystalline form, with a brown streak and metallic or greasy luster. The fracture is uneven and brittle. Crystals are octahedral. In deposits it occurs with the associated mineral serpentinite.
Chrompicotite density is 4.5-4.8 g/cm3. Hardness is 5.5-7.5.
Magnochromite
In appearance, it differs little from other chrome spinels, but has one distinguishing characteristic: unlike the minerals described above, the streak of magnochromite is not brownish but brown.
The specific weight of magnochromite is 4.2-5.1 g/cm3. Hardness is 5.5-7.
| Mineral name | Chemical formula | Density, g/cm3 | Specific weight, kg/m3 | Chromite ore weight, t/m3 |
|---|---|---|---|---|
| Chromite | FeCr2O4 | 4.5-4.8 | 4500-4800 | 4.5-4.8 |
| Alumochromite | Fe(Cr, Al)2O4 | 4.5-4.8 | 4500-4800 | 4.5-4.8 |
| Chrompicotite | (Mg, Fe)(Cr, Al)2O4 | 4.5-4.8 | 4500-4800 | 4.5-4.8 |
| Magnochromite | (Mg, Fe)Cr2O4 | 4.2-5.1 | 4200-5100 | 4.2-5.1 |
A physical feature of chromite ores is their thermal instability. During heating, they decompose with release of Fe2O3 and Al2O3. When the temperature rises to 300 degrees Celsius, hematite is released; at 520 degrees, Cr2O3 forms.
The melting temperature ranges from 450 to 2180 degrees, depending on the MgO or Cr2O3 content in the mineral.
Frequently Asked Questions
Can the density of chromite ore be used for precise calculations?
The density and weight values for chromite ore in this article are reference values. They are suitable for preliminary estimates, but design, construction, production and other critical calculations should be checked against standards, material datasheets or measurement results.
Why can the actual weight of chromite ore differ from the table?
The actual weight of chromite ore depends on composition, moisture, temperature, porosity, fraction size, material grade and measurement conditions. Because of this, real values may differ from the average table data.
How do you calculate the mass of chromite ore from density?
For an approximate calculation, use the formula: mass = density × volume. If the density of chromite ore is given in kg/m³ and the volume is in m³, the result will be in kilograms.