Dolomitic Limestone

What Is Dolomitic Limestone?

Dolomitic limestone is a sedimentary rock composed primarily of calcium magnesium carbonate (CaMg(CO₃)₂). Unlike high-calcium limestone, it contains a significant portion of magnesium carbonate (MgCO₃), typically 30–40%, with calcium carbonate (CaCO₃) around 40–50%. This dual-alkaline property makes it ideal for applications requiring both calcium and magnesium components.

Key Features:

High Magnesium Content: 10–20% MgO

Low Water Absorption: <1%, dense structure

Thermal Stability: Can be calcined into Dolomitic Quicklime (CaO·MgO)

Neutral to Mild Alkalinity: pH 7.5–8.5

Comparison with High-Calcium Limestone:

Property	Dolomitic Limestone	High-Calcium Limestone
Main Composition	CaMg(CO₃)₂	CaCO₃
MgO Content	10–20%	<2%
Calcined Product	CaO + MgO	CaO
Acid Resistance	Higher	Moderate

Production Process & Quality Control

Mining & Processing

Ore Selection:

High-purity dolomite deposits (CaCO₃ + MgCO₃ ≥ 95%)

Low silica content (SiO₂ < 1.5%)

Crushing & Sizing:

Primary → Secondary → Tertiary crushing (Jaw + Cone Crushers)

Screening: 0-5mm (Agriculture), 5-20mm (Metallurgy), 20-50mm (Construction)

Calcination (Optional):

Heated at 900-1100°C to produce Dolomitic Quicklime (CaO·MgO)

Quality Assurance

Chemical Analysis: XRF (CaO, MgO, SiO₂, Fe₂O₃)

Particle Size Control: Laser diffraction (D50. D97)

Whiteness: ≥85% (ISO 2470)

Bulk Density: 1.5-1.8 g/cm³ (Impacts shipping costs)

Technical Specifications of Dolomitic Limestone

Parameter	Specification	Test Method
CaCO₃ Content	40-50%	EDTA Titration
MgCO₃ Content	30-40%	X-ray Diffraction (XRD)
SiO₂ Content	≤1.5%	XRF Spectrometry
Particle Size	0.1mm-50mm (Custom)	Sieving + Laser Analysis
Loss on Ignition (LOI)	42-47%	Calcination (1000°C)
Whiteness	≥80%	ISO 2470
Bulk Density	1.3–1.6 g/cm³	ASTM C29

Applications of Dolomitic Limestone

Steel Metallurgy

Flux in Sintering: Lowers melting point and improves slag flow

BOF Steelmaking: MgO protects linings and extends converter life

Construction Materials

Magnesium Cement: Reacts with MgCl₂ to form Sorel Cement

Fireproof Panels: MgO provides thermal shielding at high temperatures

Agriculture & Soil Improvement

Soil Conditioner: Neutralizes acidity and adds Ca²⁺ + Mg²⁺

Magnesium Fertilizer: Essential for citrus, grape, and cereal crops

Environmental Remediation

Flue Gas Desulfurization (FGD): MgO enhances SO₂ absorption

Heavy Metal Stabilization: Forms stable carbonate precipitates

Chemical & Glass Industry

Magnesium Compounds: Used in MgSO₄, Mg(OH)₂ production

Glassmaking: Source of MgO in glass formulation

Why Choose Dolomitic Limestone?

✅ Dual Alkalinity: Supplies both Ca + Mg, more efficient than pure limestone

✅ Thermal Resistance: MgO improves refractory performance

✅ Cost-Effective: 30-50% cheaper than separate Ca/Mg sources

FAQ about Dolomitic Limestone

Q: Can dolomitic limestone replace high-calcium limestone?

A: Yes, but only where MgO is needed (e.g., steelmaking, magnesium cement). For general construction, high-calcium limestone is more economical.

Q: What’s the difference between raw dolomite and calcined dolomite (Dolomitic Quicklime)?

A: Calcined dolomite (CaO·MgO) is more reactive and used in high-temperature applications like FGD and metallurgy.

Q: What’s the best particle size for agricultural use?

A: 2-5mm granules balance dissolution rate and long-term soil conditioning.

Q: Can you customize particle sizes?

A: Yes! We supply 100-mesh to 10mm sizes for different industries.

Supplier Services

As China’s leading dolomite limestone supplier, Jintai offers:

✔ Own mines for stable raw material supply

✔ Precision grinding for controlled particle distribution

✔ Compliance with industry standards (construction, agriculture, steel)

✔ TDS, COA, MSDS documentation

✔ Bulk shipping options (Truck, Rail, Sea)

✔ Free technical support (soil treatment, metallurgy applications)

📩 Contact us today for samples and the latest pricing!