1. Project Overview

1.1 Project Background

Dolomite is a carbonate mineral with the chemical composition CaMg(CO₃)₂, belonging to the trigonal crystal system. It often appears grayish-white, pale yellow, or light brown due to the presence of iron, manganese, and other elements, and exhibits a vitreous luster. Dolomite is the main mineral component of dolostone and dolomitic limestone. China possesses abundant dolomite resources, mainly distributed in Hubei, Hunan, Guangxi, Guizhou, Jiangsu, and Inner Mongolia.

With the continuous growth in demand for dolomite powder in building materials, metallurgy, chemical industry, agriculture, and other sectors, processing raw dolomite ore into high-value-added powder products offers significant economic benefits. The Raymond mill is an ideal choice for dolomite pulverization due to its simple structure, low capital investment, and uniform product fineness.

1.2 Project Objectives

This study aims to demonstrate the feasibility of using a Raymond mill for dolomite pulverization, covering technical feasibility, economic feasibility, and market feasibility, so as to provide a basis for project investment decisions.

1.3 Design Principles

1. Technical advancement: Select mature and reliable Raymond milling technology and equipment.
2. Economic rationality: Pursue optimization of investment and operating costs while meeting product quality requirements.
3. Environmental compliance: Ensure that dust emissions, noise, and other indicators meet national environmental standards.
4. Operational safety: Guarantee a safe and reliable production process.

2. Raw Material Characteristics

2.1 Basic Properties of Dolomite

2.2 Suitability for Processing

The Raymond mill is widely applicable for grinding non-flammable and non-explosive minerals with Mohs hardness not exceeding 9.3 and moisture content below 6%. Dolomite, with a Mohs hardness of 3.5–4 (well below the Raymond mill’s upper limit of 7) and typically dry, fully meets the processing conditions.

2.3 Raw Material Supply Requirements

• Dimensione del mangime: Must be crushed to ≤20 mm by a jaw crusher prior to milling.
• Moisture content: Should be controlled below 6%.
• Source stability: Ensure a steady supply of ore with reasonable transportation distance.

3. Process Flow Design

3.1 Overall Process Flow

The dolomite Raymond mill production line adopts a standardized process of “crushing – grinding – classification – collection”, comprising the following four stages:

Stage 1: Pre-treatment (Crushing)

Large dolomite boulders are first crushed by a jaw crusher to a feed size of ≤20 mm. This step significantly impacts subsequent energy consumption—actual data show that reducing feed size from 30 mm to 15 mm can lower Raymond mill power consumption by 28%. A “three-stage closed-circuit crushing” process is recommended, with screening equipment returning oversized particles for re-crushing to ensure uniform particle size.

Stage 2: Grinding

The crushed dolomite particles are conveyed by a bucket elevator to a storage bin, then fed uniformly, quantitatively, and continuously into the Raymond mill main unit via an electromagnetic vibrating feeder for grinding.

Grinding principle: The transmission device drives the central shaft to rotate, and the grinding rollers on the plum blossom frame revolve around the grinding ring while also rotating on their own axes. The shovel blade system throws the material between the rollers and the ring, forming a material bed, where it is crushed by the centrifugal (compressive) force generated by the roller rotation.

Stage 3: Classification

The ground powder is carried by the fan airflow to the classifier for separation. By adjusting the classifier rotor speed, the product fineness can be precisely controlled. Fine powder meeting the required fineness is carried by the airflow to the downstream collection system; oversized coarse particles fall back to the grinding chamber for further processing, forming a closed-circuit cycle.

Stage 4: Collection and Packaging

The qualified fine powder is carried by the airflow through pipelines to a large cyclone collector for separation and collection, then discharged through the powder outlet as finished product. A pulse dust collector is recommended, achieving a dust recovery rate of up to 99.9%. Finally, automatic packaging machines are used for ton-bag packaging.

3.2 Process Flow Diagram

Raw dolomite → Jaw crusher → Bucket elevator → Storage bin → Electromagnetic vibrating feeder
    → Raymond mill main unit (grinding) → Classifier → Cyclone collector
    → Finished product silo → Automatic packaging → Finished product storage
                    ↑ (coarse powder returns)

3.3 Key Process Control Parameters

4. Equipment Selection

4.1 Major Equipment Configuration

A complete dolomite Raymond mill production line includes:

4.2 Recommended Raymond Mill Models

Based on production scale, the following commonly used models are recommended:

Product fineness can be adjusted within 80–400 mesh (0.18–0.038 mm); some upgraded models can reach 600 mesh.

4.3 Selection Recommendations

• Small-scale line (10,000–30,000 t/year): Recommend HCQ1290 or 4R series.
• Medium-scale line (30,000–80,000 t/year): Recommend HCQ1500.
• Large-scale line (>80,000 t/year): Consider multiple units in parallel or a large vertical mill.

4.4 Equipment Investment Estimate (for HCQ1500 line)

5. Product Plan and Market Analysis

5.1 Product Portfolio

Dolomite powder fineness can be flexibly adjusted according to downstream requirements:

5.2 Market Applications

Dolomite powder is widely used in the following fields:

1. Metallurgia: As a basic refractory material and flux in blast furnace ironmaking, it lowers ore melting points and improves smelting efficiency—this is the largest consumer market for dolomite.
2. Building materials and glass: Used in producing artificial marble (30% increase in hardness), ceramic glazes, and glass batch materials—often called the “industrial monosodium glutamate”.
3. Agriculture and environmental protection: As an efficient soil conditioner, it improves acidic soils and supplies calcium and magnesium nutrients, increasing crop yields by up to 20%; also used in wastewater and exhaust gas treatment.
4. Chemical and daily chemicals: Used as filler in paints, coatings, cosmetics, etc.

5.3 Market Outlook

The global dolomite powder market is projected to grow from approximately US$34 billion in 2025 to about US$49.5 billion by 2034, at a compound annual growth rate (CAGR) of about 4.27%. With growing demand for high-performance materials in new energy vehicles, 5G communications, and other industries, the application potential of ultra-fine dolomite powder in lithium battery separator coatings, electronic ceramic substrates, and other fields is continually being explored.

6. Economic Benefit Analysis

6.1 Cost Analysis (based on HCQ1500, annual output 50,000 tons)

Production cost breakdown:

6.2 Revenue Analysis

6.3 Payback Period

• Total investment: approx. 700,000–950,000 RMB (equipment only)
• Annual net profit: conservatively estimated at 3–5 million RMB
• Payback period: approx. 3–6 months

Compared with traditional R-type mills, new Raymond mills can increase production by more than 40% and reduce unit power consumption by over 30%, delivering significant economic benefits.

6.4 Sensitivity Analysis

7. Technical Feasibility Assessment

7.1 Equipment Suitability

The Raymond mill is suitable for grinding various non-flammable and non-explosive ores with Mohs hardness below 7 and moisture below 6%. Dolomite, with hardness 3.5–4 and typically dry, fully meets these conditions, making it a technically mature and suitable solution.

7.2 Product Quality

The Raymond mill produces fine powder with uniform particle size, achieving a sieving pass rate of up to 99%—a significant advantage over other grinding equipment. When equipped with a high-precision turbo classifier, particle size can be precisely controlled to meet the fineness requirements of various industries.

7.3 System Reliability

The Raymond mill has a compact three-dimensional structure with a small footprint and strong system integration. It can form an independent production system from raw material processing to pulverization and packaging. The electrical system adopts centralized control for automated operation. Equipment equipped with PLC automatic control systems can reduce failure rates by 60%.

7.4 Environmental Compliance

The system operates under negative pressure and is equipped with a pulse dust collector with a collection efficiency of up to 99.9%, effectively controlling dust emissions. Dust leakage can be reduced by 95% compared with manual operation. The entire airflow system is closed-loop and circulated, with minimal dust discharge and no environmental pollution.

8. Risk Analysis and Mitigation Measures

8.1 Technical Risks

8.2 Market Risks

8.3 Operational Risks