Salt is a fundamental raw material in the food, catering, and chemical industries. Its particle size directly impacts product quality and user experience. Improper grinding not only reduces efficiency but also causes problems such as clumping and contamination. This article comprehensively analyzes the optimal method for industrial-grade salt grinding, covering needs analysis, equipment selection, parameter optimization, and practical case studies, to help companies achieve the optimal balance between efficiency, quality, and compliance.
一. Why is a “best method” necessary for grinding salt?
Grinding salt is more than just “grinding.” Particle size, purity, and hygiene standards vary significantly across different applications (food, chemical, and cosmetics). Improper methods not only waste energy but also directly impact product quality.
1. Three Pain Points of Traditional Methods
Low Output with Manual Grinding: Daily output is less than 50 kg, and particle size is uneven.
Ordinary grinders are prone to caking and rusting: Frictional heat causes salt to absorb moisture and clump, and the carbon steel body is susceptible to corrosion.
Direct Grinding without Pretreatment: Salt containing water or impurities can easily clog the machine and burn the motor.
2. Three Criteria for “Best Methods”
Precise Particle Control: Particle size tolerance is controlled within ±1-2 mesh.
Efficient and Stable: Continuous production with energy consumption less than 5 kWh per ton.
Safety and Compliance: Contact parts are made of 304/316 stainless steel, which is easy to clean and corrosion-resistant.
II. Five-Step Method for Industrial-Grade Salt Grinding
Step 1: Identify Requirements, Determine Particle Size and Production Capacity
Before grinding, determine the target particle size and daily output.
| Application Scenario | Recommended particle size (mesh) | Features |
|---|---|---|
| Pickle processing | 10-20 | Coarse particles and uniform penetration |
| Seasoning production | 40-80 | Easy to mix and dissolve quickly |
| Bakery/beverages | 80-120 | Ultrafine dispersion |
| Chemical/water treatment | 20-40 | Uniform particle size and efficient reaction |
Hygiene Requirements:
Food-grade factories recommend using all-stainless steel construction with an automated CIP cleaning system; chemical companies require anti-corrosion coatings.
Step 2: Choose the Right Grinding Equipment – Four Core Models
1. Impact Mill – An Efficient Solution for Coarse to Medium Salt
Principle: High-speed hammer impact crushing, screens control particle size.
Features: Low energy consumption, uniform particle size, and no agglomeration.
Applications: Preserved food factories, central kitchens, and salt processing plants.
2. Airflow Mill – The Precision Choice for Fine and Ultrafine Salt
Principle: High-speed airflow causes salt particles to collide with each other, grinding them into powder.
Advantages: Particle size error less than ±1 mesh, no thermal contamination.
Applications: Seasoning, pharmaceutical, and cosmetics industries.
3. Colloid Mill – Dedicated for Wet Grinding
Principle: Stator-rotor shearing, suitable for salt slurries and liquids.
Advantages: Avoids drying and allows for direct integration into the mixing process.
Applications: Sauces, dressings, bath salt essences, etc.
4. Toothed Roller Grinder – Durable Model for Rock Salt Processing
Principle: Highly hardened toothed rollers use reverse extrusion and shearing.
Advantages: Long service life and stable continuous production.
Applications: Mineral salt and chemical salt grinding.
Step 3: Optimize Grinding Parameters to Improve Efficiency and Quality
Speed Setting:Impact Grinding: 3000-4000 r/min;
Airflow Grinding: 0.8-1.0 MPa; the finer the particle size, the higher the air pressure.
Constant Feeding: Use a vibrating feeder, and control the feed rate at 80% of the rated capacity.
Screen and Classifying Wheel:The impact grinding machine allows for direct screen replacement; the airflow grinding machine controls particle size by adjusting the classifying wheel speed.
Step 4: Pre-treatment and Post-treatment – Ensure Salt Product Stability
Pre-treatment:
Impurity Removal: Vibrating screens remove stones and impurities;
Drying: Hot air drying reduces moisture content to below 2%.
Post-treatment:
Screening: Secondary screening with a rotary vibrating screen, with a pass rate of ≥98%;
Cooling: Conveyor belt cooling prevents caking.
Step 5: Equipment Maintenance and Hygiene Management
Daily Maintenance: Clean residual salt, inspect screens, and add lubricant.
Monthly Inspection: CIP system, motor current.
Quarterly Maintenance: Replace seals and bearings, and calibrate the classifier speed.
Food Grade Requirements: 304/316 stainless steel contact surfaces, clean with food-grade solution.
III. Typical Application Cases
Case 1: Seasoning Factory (40-60 mesh, 500kg daily output)
Pain Points: Rusting of conventional machines and clumping of salt powder.
Solution: 304 stainless steel impact grinder + hot air drying + vibrating screen.
Results: Fine salt powder, 99% pass rate, 30% reduction in energy consumption.
Case 2: Preserved Food Factory (10-20 mesh, 2000kg daily output)
Pain Points: Low manual grinding efficiency and uneven particle size.
Solution: High-chromium toothed roller mill + jaw crusher pretreatment.
Results: Production capacity increased by 60%, and curing time tolerance reduced to ±0.5 hours.
Case 3: Cosmetics Company (200 mesh, 100kg daily output)
Pain Points: Difficulty in achieving ultrafine powder standards and prone to clumping.
Solution: 316 stainless steel air jet mill + vacuum drying + grading control.
Results: Particle size of 200±1 mesh, high purity, free of impurities, and meeting cosmetic standards.
IV. Avoid Four Grinding Misconceptions
Misconception 1: The finer the grind, the better.
Ultrafine salt easily absorbs moisture and clumps, which actually reduces the taste of pickled products.
Misconception 2: The larger the equipment, the better.
Actual demand less than production capacity will result in over 30% energy waste.
Misconception 3: Ignoring the corrosiveness of salt.
Carbon steel mills rust in just two months; choose 304/316 stainless steel.
Misconception 4: Starting production without a trial grind.
Different salt types have significant variations in hardness and moisture content. It is recommended to conduct a trial grind of 5-10 kg.
V. Conclusion: Matching and Optimization Are the Best Approaches
There’s no single optimal solution for grinding salt.
The key lies in matching requirements and optimizing parameters:
Food factories prioritize food-grade materials and easy cleaning;
Chemical companies focus on corrosion resistance and high production capacity;
Small workshops pursue high cost-effectiveness and stable output.
Starting with “clarifying requirements → selecting a product → optimizing the process,” and verifying parameters through free trials or customized solutions offered by the manufacturer, can achieve efficient, safe, and stable industrial-grade salt grinding.
