Raw gypsum has low hardness and low humidity, which perfectly matches the processing requirements of Raymond mill. The finished product fineness of 80-600 mesh is precisely controllable and is widely used in construction, medicine, industry and other fields. It is efficient, energy-saving and environmentally friendly.

Feasibility Analysis: Matching the Characteristics of Raw Gypsum with the Application Scope of Raymond Mill

1. Hardness and humidity requirements:

○ The hardness of raw gypsum is relatively low (Mohs hardness 2), which meets the requirement of Raymond mill for material hardness ≤ 7.

○ Raw gypsum is slightly soluble in water and has a low humidity, which usually meets the Raymond mill’s “humidity < 6%” feeding condition (if the raw material humidity is too high, it can be pre-treated by drying).

2. Particle size and finished product requirements:

○ The particle size range of the finished product of Raymond mill is 80-400 mesh (adjustable to 600 mesh), while the fineness of gypsum powder required by the fields of construction, medicine, chemical industry, etc. is usually between 200-600 mesh, which is fully covered by the particle size control capability of Raymond mill.

3. Material compatibility:

○ Raw gypsum is a non-flammable and non-explosive mineral, non-corrosive, and meets the safety operation requirements of Raymond mill.

Processing flow and advantages

1. Pretreatment → Grinding → Classification → Collection:

○ Raw material pretreatment: Large pieces of raw gypsum are crushed to less than 30mm by jaw/hammer crusher to ensure that they meet the feed particle size requirements of Raymond mill.

○ Grinding stage: After the material enters the grinding chamber, the grinding roller crushes the raw gypsum under the action of centrifugal force and then enters the classifier for screening. The coarse powder falls back to be re-ground, and the fine powder enters the powder collection system with the air flow.

○ Finished product collection: Using a combination of cyclone separator + pulse bag dust collector, the dust emission concentration can be controlled below 30mg/m³, achieving environmentally friendly production.

2. Technical advantages:

○ High efficiency and energy saving: It consumes less energy than ball mill and saves significantly more energy than traditional grinding mill.

○ Precise and controllable particle size: By adjusting the speed of the classifier, gypsum powder with a mesh size of 80-400 can be flexibly produced to meet different application scenarios (such as cement retarder, pharmaceutical filler, coating, etc.).

○ Environmental protection and automation: closed operation + intelligent control system to reduce dust pollution and manual intervention.

Expansion of application areas

● Gypsum powder processed by Raymond mill can be widely used in:

○ Construction industry: cement retarder, gypsum board raw materials, mortar additives, etc.;

○ Medical field: crushing of Chinese medicinal materials (equipment must meet pharmaceutical standards);

○ Industrial materials: paint fillers, paper coatings, model making, etc.;

○ Environmentally friendly desulfurization: The flue gas desulfurization in power plants is prepared by gypsum powder in the limestone-gypsum method.

Precautions

1. Equipment selection: Select the appropriate model (such as 5R, 6R series) based on production capacity requirements and ensure that the pretreatment equipment is matched.

2. Safe operation: Gypsum dust is harmful if inhaled (R20/21/22 warning). Wear dust-proof equipment and maintain a negative pressure environment in the workshop.

3. Quality control: Control the particle size and humidity of the feed to avoid clogging or excessive wear of the grinding roller.

4. Pharmaceutical standards: If used for medical purposes, a dedicated Raymond mill that meets GMP standards must be selected, and the purity testing of the finished product must be strengthened.