Are You Still “Galloping” with High-Cost Traditional Mills for Your 50μm Dolomite Powder?

5TPH Dolomite Ultrafine Powder Solution | Raw Material 20mm, Finished Product 50μm | Vertical Mill

With the explosive growth of the global new energy, photovoltaic glass, specialty ceramics, and high-end coatings industries, the market demand for ultrafine dolomite powder (<50 microns) continues to rise. However, a core pain point faced by many dolomite mines is that the raw material has uneven block size (<20mm) and high moisture content (<5%), yet the finished product fineness must reach the micron level, and the single-machine capacity must be stable at 5 tons/hour.

As a professional grinding equipment manufacturer, we understand that simply scaling up equipment models cannot solve the industry's persistent problems of "high energy consumption, low output, and easy clogging." This article will deeply analyze the complete process design for such raw material characteristics and finished product requirements, and provide verified industrial application cases.

Demand Insight: Three Major Technological Gaps from "<20mm Block Material" to "<50μm Micro Powder"

1. The Dual Nature of Raw Material Characteristics

The raw material provided by the customer is dolomite blocks, with the size already controlled below 20mm. This seemingly "simplifies the coarse crushing process," but in reality, it brings new challenges to the grinding section:

• Flowability issues: Particles smaller than 20mm easily "bump" in the hopper, leading to uneven feeding;

• Bulk density of 1.6t/m³: The material has a high specific gravity, placing extremely high demands on the impact load on the grinding rollers;

• Moisture <5%: Although not extremely high, 5% moisture content in ultrafine grinding (<50μm) easily leads to "grinding" and classifier blade sticking.

2. The "Seesaw Effect" Between Capacity and Fineness

Achieving a capacity of 5 tons/hour, with over 90% of the product passing through a 50-micron (equivalent to 325 mesh) sieve, falls within the scope of large-scale ultrafine powder processing. At this fineness, the capacity of ordinary Raymond mills or ring roller mills typically decreases to less than 40% of the nominal value, and the consumption of vulnerable parts increases exponentially.

Process Overview: Vertical Roller Mill and Classifier Closed-Loop System

For the specific requirements of "20mm feed, 5t/h, D50 < 50μm", we recommend the ultrafine vertical mill + high-efficiency turbine classifier closed-loop system.

Core Equipment Logic

HGM Grinding Mill

1. HGM Ultrafine Vertical Mill: Employs a conical grinding roller and flat disc liner design. For fine materials below 20mm, the grinding roller pressure is adjusted for "low resistance" to avoid severe vibration caused by "too thin a material layer". Its internal classifier can pre-separate coarse powder of about 100 mesh, significantly reducing the burden on the downstream classifier.

2. External High-Efficiency Turbine Classifier: This is crucial to ensuring that the finished product is 100% < 50μm. The semi-finished product after grinding in the vertical mill enters the classifier, where the particle size is precisely cut using frequency conversion speed regulation. Unqualified coarse powder is returned to the mill, while only qualified micro-powder is sent to the dust collector.

Addressing Three Major Pain Points

• Feeding Stability: A fluidizing air cushion and variable frequency steady-flow feeder at the bottom of the silo completely solve the arching problem of high-density material (1.6t/m³).

• Wear-Resistant Design: For dolomite (Mohs hardness 3.5-4), the grinding rollers and liners are made of high-chromium alloy welded together, with a design life of ≥8000 hours.

• Dehumidification and Temperature Control: A hot air furnace is used to control the inlet air temperature below 120℃, directly evaporating 5% of the moisture during the grinding process to a finished product moisture content of <0.5%.

Advantages and Highlights: Why can this configuration achieve a stable output of 5 tons?

1. Low Energy Consumption: Compared to traditional ball mills, this vertical mill system reduces unit power consumption by more than 35% at a fineness of D97 < 50μm, with measured power consumption per ton of powder ≤45kW·h.

2. Particle Shape Control: The finished powder particles are regular blocky or acute-angled polygonal in shape, with a moderate specific surface area, making it particularly suitable as a filler for photovoltaic glass clarifying agents. Its flowability is superior to ordinary round-particle powder.

3. Wear-Resistant Structure: The grinding rollers can be flipped for maintenance, reducing downtime by 70% and ensuring continuous production.

Case Study: Dolomite Powder Production Project for an Indian Photovoltaic Materials Company

Operating Background:

• Incoming Material: Dolomite, size 0-15mm, moisture 4%-5.5%

• Finished Product Requirements: D97 ≤ 45μm (more stringent than the customer's current requirement of <50μm)

• Designed Production Capacity: 5 tons/hour

Configuration Scheme: HRM19X Vertical Mill + NHF350 High-Efficiency Classifier

Operating Data:

• Actual Output: Stable at 5.2 tons/hour - 5.6 tons/hour;

• Finished Product Fineness: Multiple sampling tests showed D97 consistently at 43.8μm, far exceeding the contract specifications;

• Energy Consumption Feedback: After 6 months of continuous operation, the customer's average electricity consumption per ton of powder was 42 kWh, a 35% saving compared to their existing used ball mill system;

• Wear Part Life: The first batch of grinding roller liners exceeded 9000 hours of operation and is still usable.

Customer Testimonial: "We were initially worried that the vertical mill wouldn't be able to handle 20mm fine particles, but the hydraulic accumulator in this system actually made the operation smoother. The 50-micron powder output is two-thirds cheaper than the air jet mill used in our neighboring factory."

Related Equipment Recommendations: Building a Complete Production Matrix

If you are evaluating dolomite ultrafine powder projects with different capacity gradients, you can refer to the following selection:

• Small-scale pilot/small-scale production (1-2t/h, D50<50μm):

• Recommended: High-pressure suspension roller mill (improved version) or small vertical mill.

• Features: Small footprint, low investment threshold, suitable for specialty chemical companies with their own powder workshops.

• Medium-scale production line (4-6t/h, D50<50μm):

• Recommended: HLM ultrafine vertical mill (as described in the core solution above).

• Features: Extremely high energy consumption control precision compared to separators, stable ultrafine powder production capacity.

• Supporting Auxiliary Equipment:

• Pulse Jet Bag Filter: Emission concentration ≤10mg/Nm³, meeting the most stringent global environmental standards.

• Automatic Packaging Machine: Equipped with a spiral air-feeding device to address the dust-prone characteristics of ultrafine powders, achieving fully automatic packaging of 25kg/ton bags.

Frequently Asked Questions

Q1: Why can't a regular Raymond mill be used directly to produce 5t/h of dolomite powder <50μm?

A: The optimal grinding range for a regular Raymond mill is typically 80-400 mesh (180μm-38μm). When large-scale (5t/h) grinding of materials to <50μm is required, the grinding chamber temperature of the Raymond mill will rise sharply, and the spring pressure will be insufficient, leading to severe "powder spraying" and a production rate typically less than 30% of the nominal value. Furthermore, the sieve bottom is extremely prone to damage. Vertical mills, on the other hand, use hydraulic pressure, resulting in constant grinding force, making them suitable for large-scale production of ultrafine powders.

Q2: Is a drying system necessary if the raw material moisture content is <5%?

A: Temperature-controlled hot air is essential. Even with only 5% moisture, in its micronized state, moisture easily causes the powder to adhere and scale on pipes and classifier blades. Our system utilizes waste heat from the mill or a small hot air furnace to provide an upward airflow of approximately 120°C, simultaneously drying the powder during grinding and sorting to ensure a dry finished product and prevent clogging.

Q3: Which industries primarily sell dolomite powder with a finished product size <50 microns?

A: There are three main markets:

1. Photovoltaic glass: As a calcium supplement for high-transmittance glass, it requires low iron content and a narrow particle size distribution.

2. High-end plastics/rubber fillers: Replacing light calcium carbonate to improve product dimensional stability.

3. Environmental desulfurization: Dry desulfurization of power plant flue gas; ultrafine powders have higher reactivity.

About of Baichy Heavy Industry

Baichy Heavy Industry is a high-tech mining equipment company integrating R&D, manufacturing, sales, and after-sales service. Focusing on crushing, grinding, and mineral processing equipment, we provide professional solutions to our customers. We are ISO9001:2015 、certified, and our products include mobile crushing palnts, crawler crushing plant, construction waste crushing plants, jaw crushers, sand making machines, cone crushers, fine crushers, grinding mills, ball mills, etc., all with reliable performance to meet diverse project needs.

Our advantages:

• Professional pre-sales support: Free project design and comprehensive solutions to help you accurately select the right equipment;

• Comprehensive on-site service: Providing installation guidance and worker training to ensure smooth equipment commissioning;

• Reliable after-sales guarantee: A complete after-sales system, timely response to technical inquiries and equipment maintenance, ensuring long-term stable operation.

To protect your rights, please contact us through the following official channels for professional service:

Official Website Customer Service

WhatsApp: 0086-15093222637

Email: [email protected]

We are committed to providing high-quality equipment and full-cycle services to deliver comprehensive intelligent solutions for the global mining industry!