Ultrafine fly ash grinding technology significantly enhances the activity of volcanic ash by optimizing particle morphology and fineness, allowing it to achieve greater value in areas such as cement and concrete. This technology combines environmental and economic advantages, promoting the resource utilization of industrial waste and providing key support for green manufacturing.

Ultrafine grinding of fly ash, a reactive mineral resource found in industrial waste, is crucial for enhancing its application value. This article comprehensively analyzes the current status and prospects of ultrafine grinding of fly ash from multiple perspectives, including production processes, system characteristics, technological developments, application areas, and future trends.

1. Overview of fly ash ultrafine grinding

Ultrafine fly ash grinding is a system based on the open-flow mill production process. By optimizing fly ash particle morphology, reducing water demand, and enhancing its pozzolanic activity in cement, concrete, and other applications, this technology aims to process raw fly ash to meet national Class I and II fine ash standards (e.g., GB/T 1956-2005), transforming coarse or substandard fly ash into high-value-added products. The core goal is to maximize fly ash’s pozzolanic activity, morphological properties, and microaggregate effects through increased fineness, thereby increasing its utilization in building materials.

2. Fly ash ultrafine grinding production process

1. System composition

The ultrafine grinding system includes core subsystems such as coarse ash feeding, grinding, pneumatic conveying, and finished product storage. It adopts PLC automatic control, with a simple process flow and low maintenance cost. It is divided into open circuit and closed circuit systems according to the process path:

2. Open circuit system process

○ Ash collection: quantitative feeding from the coarse ash storage;

○ Grinding: Grind directly into fine ash that meets the standards through a special ultra-fine high-efficiency screening mill;

○ Tail gas emission: dust treatment;

○ Out of mill: finished products are delivered to the warehouse through continuous conveying pumps.

○ Features: No screening or sorting required, high degree of automation, suitable for small and medium-sized production.

3. Closed-loop system and combined process

○ Introduce grading equipment (such as DS high-efficiency classifier), classify first and then grind to avoid over-grinding;

○ The coarse ash storage and sorting system can be designed in conjunction to improve efficiency;

○ Typical equipment includes vertical mill, roller press, ball mill system, etc., combined with drying and powder selection technology.

3. Technical Features and Performance Advantages

1. Finished product quality

○ The fineness meets the standard (such as low 45μm sieve residue), the water demand ratio is optimized, and the activity of the volcanic ash is significantly improved;

○ Improve particle morphology and enhance concrete fluidity and density.

2. Environmental protection and efficiency

○ Each dust-generating point is equipped with a bag dust collector to prevent secondary pollution;

○ PLC+CRT control realizes multi-mode operation and automated production management;

○ The equipment has high configuration, eliminating leakage and its operation reliability is better than traditional cement mill system.

3. Economical

○ Open flow technology reduces system complexity and investment;

○ The closed-circuit system improves grinding efficiency through classification technology and consumes less power than the open-circuit system.

IV. Application Fields and Benefits

1. Building materials

○ Cement admixture: replace part of clinker to improve cement strength and durability;

○ High-performance concrete: improves fluidity, impermeability, and frost resistance, and reduces water demand.

2. Social benefits

○ Utilize industrial waste residue as a resource to reduce environmental load;

○ Increase the added value of fly ash from power plants and promote the circular economy.

3. Economic benefits

○ Sorting and ultra-fine grinding technologies upgrade fly ash from coarse ash to commercial ash, increasing corporate profits;