D10, D50, and D90 are key parameters in **particle size distribution analysis**, used to describe the cumulative distribution of particle sizes in a granular system. Their definitions, significance, and differences are as follows:

---

### **1. Definitions and Meanings**

- **D10**: Represents the particle size at which **10% of the total particle volume is smaller than this value**. It characterizes the distribution of fine particles in the system.

- **D50**: Known as the **median particle size** or midpoint value, it indicates the particle size at the 50% cumulative distribution mark. **Half of the particles are smaller than this size, and the other half are larger**. D50 is commonly used to represent the average particle size of the system.

- **D90**: Represents the particle size at which **90% of the total particle volume is smaller than this value**. It reflects the distribution of coarse particles and is critical for quality control.

---

### **2. Differences and Roles**

| Parameter | Core Significance                     | Application Scenarios                 | Typical Use Cases                   |

|-----------|---------------------------------------|----------------------------------------|-------------------------------------|

| **D10**   | Threshold for fine particles, indicating their proportion | Evaluating material flowability and dispersion | Controlling side effects of fine powders in pharmaceuticals |

| **D50**   | Represents average particle size, dividing the distribution | Characterizing overall particle size  | Measuring average grain size in powder industries |

| **D90**   | Threshold for coarse particles, indicating their proportion | Controlling maximum particle size to prevent defects | Avoiding surface roughness caused by large particles in coatings |

---

### **3. Practical Applications**

- **Pharmaceuticals**: D90 must be controlled to avoid oversized particles affecting drug dissolution, while D10 is monitored to mitigate risks from ultrafine particles.

- **Environmental Science**: D50 assesses average pollution levels of airborne/waterborne particles, while D90 highlights extreme coarse contaminants.

- **Materials Science**: D10 and D90 jointly constrain the particle size range to ensure material stability (e.g., ceramic sintering strength).

---

### **4. Measurement Methods**

Particle size distribution is typically measured using **laser diffraction analyzers**, which rely on the relationship between particle size and light scattering angles: **larger particles scatter light at smaller angles**. The intensity of scattered light at different angles is analyzed to calculate these parameters.

---

### **Summary**

D10, D50, and D90 comprehensively describe particle size distributions by quantifying cumulative percentages at key thresholds. D50 serves as the central average metric, while D10 and D90 define the fine and coarse boundaries of the distribution. These parameters are vital in industrial production and research, directly impacting product performance and process design.