GYPSUM POWDER GRINDING MACHINE
A practical engineering reference for gypsum mineralogy, crushing, metered conveying, dry grinding, air classification and calcination - with CRGM80, CRGM100 and CRGM125 as the ultrafine equipment platform.
01 / Material intelligence
Its value comes from reversible hydration chemistry. Grinding changes surface area and reaction rate; calcination changes the crystal water and binding behavior. The two operations must therefore be designed together.
THE HYDRATION LOOP
Overheating can push material toward soluble or insoluble anhydrite. Residence time, gas temperature and particle size all influence the final plaster response.
02 / Global resource context
Evaporite basins occur on every inhabited continent. Major mined supply is reported from China, the United States, Iran, Oman, Turkey, Spain and Thailand, while synthetic gypsum from flue-gas desulfurization and other industrial processes also feeds wallboard and cement markets.
Deposit origin matters: marine evaporites can contain anhydrite, carbonates, clay and salts; recycled wallboard adds paper and variable moisture. Each source needs a representative sample, not only a chemical certificate.
Source: USGS Mineral Commodity Summaries, Gypsum (2025)Values are rounded planning context from USGS reporting, not a reserve estimate or purchasing forecast.
03 / Particle size by use
Mesh labels are approximate. Specify a laser PSD, top size, residue test and application property whenever the powder is performance-critical.
04 / Process route
The exact order of grinding and calcination varies by product and kiln technology. This dry route describes a common mineral-powder preparation line.
Jaw or hammer crushing reduces quarried gypsum to a stable top size. A magnet and scalping screen protect downstream equipment.
A hopper, bin activator and variable-speed feeder decouple the crusher from the mill and stabilize circulating load.
Free moisture is measured. Drying or warm process air is considered when coating, bridging or poor separation is likely.
Material is repeatedly compressed and sheared between the grinding rings and rollers until it can enter the air stream.
Fine particles pass the classifier; coarse particles return to the grinding zone. Rotor speed and airflow set the cut point together.
Cyclone and bag filtration recover powder. It can be sent to silos, packing, blending or a controlled calcination stage.
PROCESS VARIABLES TO LOCK
Process reference: U.S. EPA AP-42, Gypsum Manufacturing. Final line arrangement depends on product route and local requirements.
05 / Equipment selection
Choose from the full PSD, capacity at that PSD, energy, footprint, contamination, maintenance and the properties required after calcination.
Commonly 80-400 mesh
Best when: the product accepts a conventional PSD and robust simplicity is the priority.
Broad fine to ultrafine duty
Best when: plant scale, wet processing or existing infrastructure justifies the circuit.
Catalogue range 5-74 um
Best when: ultrafine dry powder, compact layout and repeatable multi-grade production are central.
Dynamic classifierGrinding rings & rollersAir inlet & collection loop06 / Working principle
Feed enters the mill and falls toward the rotating grinding assembly. Centrifugal motion distributes it through multiple roller-and-ring levels. Each pass applies compression, shear and limited impact, progressively reducing the brittle gypsum.
A process fan carries liberated particles upward. The dynamic classifier rejects particles above the operating cut point and returns them to the grinding zone. Accepted fines continue to cyclone and bag collection. Because the circuit is closed, feeder rate, main-mill load, airflow and classifier speed must be tuned as one system.
07 / Catalogue technical data
These are catalogue reference values, not a gypsum output guarantee. Final capacity changes with feed moisture, purity, gypsum/anhydrite ratio, target PSD and test method.
| Parameter | CRGM80 | CRGM100 | CRGM125 |
|---|---|---|---|
| Maximum feed size | 20 mm | ||
| Ring diameter | 800 mm | 1,000 mm | 1,250 mm |
| Grinding rings / rollers | 3 / 21 | 4 / 28 | 4 / 32 |
| Main shaft speed | 230-240 rpm | 180-200 rpm | 135-155 rpm |
| Product fineness | 5-74 um | 5-74 um | 7-74 um |
| Catalogue capacity | 0.5-4.5 t/h | 1.8-5 t/h | 1.5-12 t/h |
| Main unit power | 75 kW | 132 kW | 185 kW |
| Classifier power | 18.5 kW | 30 kW | 75 kW |
| Blower power | 45 kW | 75 kW | 132 kW |
| Discharge valve | 0.75 x 2 kW | 1.1 kW | 1.5 kW |
| Screw conveyor | 3 kW | 4 kW | 4 kW |
| Total installed power | 143 kW | 244 kW | 401 kW |
| Overall dimensions (L x W x H) | 15.9 x 4.2 x 6.1 m | 19.7 x 4.7 x 7.7 m | 23.2 x 4.7 x 7.7 m |
Source: CRONUS Grinding Mill Catalog supplied with this project. Ask for a representative gypsum test before fixing capacity, power consumption or guaranteed residue.
08 / Engineering advantages
No mill is automatically efficient. The following benefits appear when the feed is conditioned, the classifier is correctly selected and the circuit operates near its stable design point.
Oversize material is internally returned instead of leaving with the product, helping control the coarse tail.
Multiple stressed contacts are arranged vertically in one main unit, reducing the footprint of the grinding stage.
Wear management focuses on engineered rollers, rings and pins rather than a large inventory of grinding balls.
Recorded feeder, airflow and classifier recipes can support several validated product grades from one line.
A correctly balanced fan and filter circuit helps manage dust at transfer points and supports clean production.
Wear surfaces are inspectable and replaceable; condition trends can be tied to a planned maintenance schedule.
09 / Related applications
CRGM equipment is intended for brittle non-flammable, non-explosive mineral feeds within the verified hardness, moisture and contamination limits.
GypsumPlaster, board, filler, cement
CalciteCoatings, plastics, paper
KaolinCeramics, coatings, filler
DolomiteGlass, agriculture, filler10 / Field evidence
The project media below document Cronus ultrafine mineral lines and workshop assembly. Material identity and guaranteed performance remain project-specific and are not inferred from a photograph.
11 / Wear parts & spares
Quartz contamination, feed top size, target fineness and unstable operation can dominate wear cost. A spare-parts plan should begin with the mineralogy report.
Primary stressed surface; inspect profile, mass loss and mounting condition.
Mating wear surface; replace as a controlled set when geometry affects product or vibration.
Check clearance, lubrication condition and fatigue indicators during planned shutdowns.
Cleanliness, balance and blade condition directly influence separation consistency.
12 / Cronus & Guilin Mining Machinery
Shanghai Cronus Machinery Co., Ltd. is a subsidiary of Guilin Mining Machinery Co., Ltd. Guilin Mining Machinery was founded in 1973 and developed as a specialist manufacturer of grinding and mineral-processing equipment.
The manufacturing base combines machining, welding, assembly, testing and after-sales teams. This long production history matters most where it becomes practical: mature drawings, repeatable fits, original spare parts, experienced commissioning and the ability to review unusual mineral behavior.
13 / Quality credentials
Project compliance must be checked against the current certificate scope, model, destination market and contract documents.
14 / Project lifecycle
Scope is agreed project by project and can include remote or arranged on-site support.
Assay, moisture, mineralogy, feed PSD, target PSD and application requirements.
Grinding trial, classifier review, mass balance, equipment list and layout inputs.
Drawing control, fabrication, assembly checks and documentation package.
Foundation, erection, alignment, ducting, electrical and interlock review.
Start-up sequence, recipes, sampling, safety, maintenance and operator training.
Trend review, troubleshooting, optimization and original spare-part planning.
15 / Engineering FAQ
A useful proposal starts with material and product data, not only a requested model number.
Both routes exist. Pre-grinding can improve heat transfer and calcination uniformity; post-calcination grinding can adjust stucco fineness. The best route depends on kiln type, desired crystal phase, handling and product setting properties.
The catalogue maximum is 20 mm. A narrower and stable crusher product is usually better for feeding, power stability and predictable wear.
Not always. Measure free moisture through seasonal variation. Drying or warm air becomes relevant when the feed coats surfaces, bridges in bins or weakens air classification.
Potentially, after removing paper, metal and other contaminants and confirming moisture and flow behavior. FGD gypsum often needs dewatering and drying; recycled wallboard needs robust separation.
Use a laser particle-size distribution with D10, D50 and D97 or a clearly defined sieve residue. Also state the test method, moisture condition and application performance target.
Compare required capacity at the agreed PSD, operating hours, feed properties, power supply, building height and future grade mix. The material test and process balance should confirm the model.
For conventional 80-325 or roughly 400-mesh products, a Raymond mill may offer simpler operation and lower project complexity. Compare tested output, residue and energy before deciding.
It may suit very large plants, wet grinding, an existing ball-mill infrastructure or products that benefit from its breakage mechanism. Review footprint, media wear and contamination.
Classifier speed, airflow, feed rate, grinding condition and circulating load interact. Changing one variable can shift both capacity and PSD, so validated operating recipes are important.
Quartz and hard impurities, oversize feed, very fine targets, unstable feeding, incorrect air balance and delayed maintenance can all accelerate wear.
Yes, within the tested operating window. Each grade needs a documented recipe, sampling method, suitable silo routing and a changeover procedure.
Project scope can include crushing, magnetic separation, feeding, conveying, grinding, classification, cyclone, bag filter, silos, packing and electrical control. Calcination can be coordinated according to the selected route.
Send material source, assay, moisture, feed size, target PSD or sieve residue, application, capacity, annual hours, voltage, altitude, climate, packing method and site layout.
Documentation, installation guidance, remote or arranged site commissioning, operator training, process follow-up and original spare-part support can be included in the project scope.
START WITH THE MATERIAL
We can review the process route when you provide feed and product data. The inquiry form opens a prepared email in your mail application; no information is silently stored by this page.
