Henan Hongke Heavy Machinery Co., Ltd. is pleased to announce the successful shipment of a Φ3.0×60m dolomite rotary kiln to a customer in Inner Mongolia, China. This project demonstrates our capability to deliver specialized calcination solutions for the magnesium and refractory materials industries.
Project Background: Dolomite Calcination for Magnesium Production
Dolomite is a double carbonate mineral composed of calcium carbonate (CaCO₃) and magnesium carbonate (MgCO₃). When calcined, dolomite undergoes thermal decomposition to produce "dolime" (CaO·MgO), a critical raw material for magnesium smelting, steelmaking, glass manufacturing, and refractory ceramics .
Our customer in Inner Mongolia operates in the magnesium production sector, where active dolomite is essential for the Pidgeon process – the dominant method for magnesium extraction. The quality of calcined dolomite directly affects reduction efficiency, magnesium yield, and overall production costs.
The customer's existing shaft kilns could not consistently deliver the reactivity and uniformity required for efficient magnesium reduction. They needed a modern rotary kiln that could produce high-quality calcined dolomite with consistent activity levels while maintaining stable 24/7 operation.
The Challenge: Consistent Quality and High Throughput
Before partnering with Henan Hongke Machinery, the customer faced several operational challenges:
| Challenge | Impact |
|---|---|
| Variable calcination quality | Inconsistent reactivity affected magnesium reduction efficiency |
| High fuel consumption | Shaft kiln design wasted thermal energy |
| Limited capacity | Could not meet growing production targets |
| Manual operation | Required constant operator intervention |
| Environmental pressure | Dust emissions exceeded local standards |
The customer required a reliable, energy-efficient rotary kiln system capable of producing 100 tons per day of high-quality calcined dolomite, with stable reactivity and low residual CO₂.
Our Solution: Φ3.0×60m Dolomite Rotary Kiln
Henan Hongke Heavy Machinery engineered a complete calcination system centered around a Φ3.0×60m rotary kiln – a proven configuration for dolomite processing in the magnesium industry.
Key Equipment Specifications
| Parameter | Value |
|---|---|
| Kiln diameter | 3.0 meters |
| Kiln length | 60 meters |
| Capacity (design) | 100 tons per day (adjustable) |
| Operating temperature | 1,100–1,250°C |
| Kiln inclination | 3.5–4% |
| Rotation speed | Variable frequency drive (0.5–3.5 rpm) |
| Drive system | Heavy-duty gear drive with auxiliary motor |
| Sealing system | Labyrinth seals with air purge at both ends |
Complete System Configuration
1. Vertical Preheater
The preheater recovers thermal energy from kiln exhaust gases to preheat dolomite feed to approximately 800–900°C before it enters the kiln, achieving 25–35% pre-calcination. This reduces fuel consumption by up to 30% compared to non-preheater configurations.
2. Φ3.0×60m Rotary Kiln
The core calcination unit features a high-quality carbon steel shell with high-alumina refractory lining. At temperatures between 1,100°C and 1,250°C, dolomite decomposes according to the reaction:
CaMg(CO₃)₂ + heat → CaO·MgO + 2CO₂↑
The 60-meter length provides sufficient residence time for complete calcination, ensuring high reactivity of the finished product – a critical factor for magnesium reduction efficiency.
3. Vertical Cooler
The cooler rapidly quenches hot calcined dolomite from approximately 1,100°C to below 100°C, preserving reactivity. The hot cooling air is recovered and recycled to the kiln as secondary combustion air, further improving thermal efficiency.
4. Dust Collection System
A two-stage dust collection system – cyclone pre-separator followed by bag filter – ensures outlet dust concentrations consistently below 30–50 mg/Nm³, meeting national environmental standards.
5. Automation & Control
PLC-based centralized control monitors temperature profiles, feed rates, kiln rotation speed, and emissions in real time, ensuring consistent product quality with minimal operator intervention.
Why Dolomite Calcination Requires a Rotary Kiln
Dolomite calcination is not a simple process. The thermal decomposition of dolomite occurs in either a single-step or two-step reaction, with decomposition beginning between approximately 500°C and 750°C . Achieving complete calcination while maintaining product reactivity requires:
Precise temperature control – to avoid over-burning and loss of reactivity
Uniform heat distribution – for consistent product quality
Adequate residence time – for complete decomposition
Rapid cooling – to preserve the reactive oxide structure
Rotary kilns are the preferred technology for dolomite calcination in the magnesium industry due to their ability to meet all these requirements reliably .
Customer Benefits
Once fully operational, this dolomite calcination line will deliver:
| Benefit | Impact |
|---|---|
| Consistent product quality | High reactivity dolime for stable magnesium reduction |
| Energy-efficient operation | ~30% fuel savings via preheater recovery |
| Increased production capacity | 100 TPD meets growing demand |
| Reduced labor costs | Automated controls minimize operator needs |
| Environmental compliance | Dust emissions controlled to national standards |
About Henan Hongke Heavy Machinery Co., Ltd.
Henan Hongke Heavy Machinery Co., Ltd. (Henan Hongke Machinery) has been manufacturing industrial processing equipment since 2006. Our product portfolio includes:
Rotary Kilns – for lime, dolomite, cement, metallurgy, and mineral calcination
Rotary Dryers – for sludge, biomass, and industrial materials
Ball Mills – for ore, slag, cement, and chemical grinding
Crushers – for primary and secondary size reduction
We provide custom engineering, full manufacturing, installation guidance, and after-sales support for customers worldwide.
Summary
The Φ3.0×60m dolomite rotary kiln project in Inner Mongolia demonstrates Henan Hongke Machinery's ability to deliver specialized calcination solutions for the magnesium industry. By integrating preheater technology, advanced sealing, extended kiln length, and automated controls, the system will produce high-reactivity calcined dolomite with optimized fuel consumption and stable 24/7 operation.
For dolomite calcination, magnesium production, or other thermal processing applications, contact Henan Hongke Heavy Machinery Co., Ltd.
Henan Hongke Heavy Machinery Co., Ltd.
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