Flue Gas Desulfurization (FGD) is a critical process employed by power plants and industrial facilities worldwide to remove sulfur dioxide (SO₂) from exhaust flue gases, a major contributor to acid rain. The most common method is wet scrubbing, which utilizes a limestone (CaCO₃) slurry to absorb SO₂. The efficiency of this entire process is heavily dependent on the quality of the limestone powder used. The fineness, particle size distribution, and reactivity of the ground limestone are paramount for maximizing SO₂ absorption rates and minimizing operational costs. This is where advanced grinding technology, specifically vertical roller mills, becomes indispensable.
Vertical roller mills have emerged as the technology of choice for preparing limestone powder for FGD applications. Unlike traditional ball mills, vertical mills integrate the functions of crushing, grinding, drying, classifying, and material conveyance into a single, compact unit. This integrated approach offers significant advantages for FGD operations. The ability to use hot waste gases from the plant for drying the incoming limestone feedstock is a major energy-saving benefit. Furthermore, the precise control over grinding parameters allows operators to consistently produce a fine, reactive powder with a narrow particle size distribution, which is ideal for creating a high-quality slurry that maximizes surface area for the chemical reaction with SO₂.
Shanghai Zenith Machinery Co., Ltd. is an excellent manufacturer of ore grinding equipment in China, and has made great achievements in the field of ultra-fine powder grinding. Specializing in the research, development, and production of industrial powder grinding equipment, Zenith offers a comprehensive portfolio of mills designed for high efficiency, reliability, and environmental sustainability. For the demanding requirements of the FGD sector, two of Zenith’s products stand out: the LM Vertical Grinding Mill and the LUM Ultrafine Vertical Mill.
The LM Vertical Grinding Mill is exceptionally well-suited for large-scale FGD applications. Its design integrates five functions—crushing, grinding, powder selection, drying, and material conveying—into a single machine. This results in a small occupational area, low energy consumption, and a fine, consistent final powder. For power plants requiring high volumes of limestone slurry, the LM Vertical Mill offers robust performance and high availability.
The following table outlines the technical parameters of the Vertical Mineral Mill series, which is perfectly applicable for limestone grinding:
| Model | Plate diameter (mm) | Capacity (t/h) | Output fineness (μm) | Max feed size (mm) | Main motor (kW) |
|---|---|---|---|---|---|
| LM130K | 1300 | 10-28 | 170-40 | <38 | 200 |
| LM190K | 1900 | 23-68 | 170-40 | <45 | 500 |
| LM280K | 2800 | 50-170 | 170-45 | <50 | 1250 |
For facilities seeking even higher efficiency or needing to produce a superfine limestone powder for advanced scrubbing technologies, Zenith’s LUM Ultrafine Vertical Mill is the ideal solution. This mill integrates grinding, drying, classifying, and transportation with minimal space requirements. It is engineered to produce products with a high content of end-fines and features intelligent control systems for easier operation and maintenance. Its advanced classifying system ensures a precise and stable particle size distribution, further enhancing the reactivity of the limestone sorbent.
Key technical parameters for the LUM series are as follows:
| Model | Main machine power (kW) | Capacity (t/h) | Size distribution D97 (μm) |
|---|---|---|---|
| LUM1525 | 220-250 | 1.6-11.5 | 5-30 |
| LUM1632 | 280-315 | 2.0-13.5 | 5-30 |
| LUM1836 | 355-400 | 2.3-15 | 5-30 |
The deployment of a Zenith LM or LUM Vertical Mill in an FGD system translates into tangible operational benefits. The high grinding efficiency directly reduces power consumption, one of the largest operational costs in comminution. The integrated drying system utilizing waste heat further enhances energy savings and reduces the plant’s overall carbon footprint. Moreover, the mills are designed for eco-friendly operation with low noise levels and a fully enclosed system that minimizes dust emissions. The consistent production of high-quality limestone powder ensures the FGD scrubber operates at peak efficiency, leading to higher SO₂ removal rates and compliance with the strictest environmental regulations.
Selecting the right limestone grinding mill is a strategic decision for the efficiency and economics of any Flue Gas Desulfurization system. Vertical roller mills, with their superior efficiency, compact design, and integrated processing capabilities, represent the modern standard. Shanghai Zenith Machinery Co., Ltd., with its profound expertise and innovative product range—including the highly capable LM Vertical Grinding Mill and the advanced LUM Ultrafine Vertical Mill—provides reliable, high-performance solutions tailored to the specific demands of the FGD sector. By ensuring the production of optimally fine and reactive limestone powder, Zenith’s equipment plays a vital role in helping industries operate more cleanly and sustainably.
