In the steel production process, especially in short-process steelmaking and electric arc furnace (EAF) operations, the quality of raw materials directly impacts energy efficiency, yield, and final product performance. Among these, sintered ore tumbler strength is a critical physical indicator that reflects the mechanical durability of sinter during handling and blast furnace charging. Accurate testing ensures optimal furnace operation and reduced fines generation.
As a leading manufacturer of rolling mill equipment and short-process steelmaking systems, we emphasize standardized material testing protocols—such as the sintered ore tumbler strength test method—to support high-efficiency, low-emission steel production.
Standard Sintered Ore Tumbler Strength Test Procedure
1. Sampling
- Belt sampling: Collect 8 kg every 15 minutes. Over 4 hours, gather 16 samples (~120 kg) to form one composite test batch.
- Minimum of two independent samplings per day are recommended.
- Samples must be taken across the entire cross-section of the conveyor belt to ensure representativeness.
- For stockpile sampling, follow standard bulk material sampling guidelines.
2. Drying
If the sinter has been watered or stored outdoors, dry it at 105 ± 5°C before testing to remove surface moisture.
3. Sample Size Requirement
The total sample must contain at least 60 kg of the 10.0–40.0 mm size fraction.
4. Sieve Analysis
Perform four-stage sieving: 40.0 mm, 25.0 mm, 16.0 mm, and 10.0 mm. Record weights and calculate percentage distribution.
5. Test Sample Preparation
The tumbler test uses a blend of three size fractions:
- 40.0–25.0 mm
- 25.0–16.0 mm
- 16.0–10.0 mm
These are mixed in proportion to their sieve percentages to form a 15.0 ± 0.15 kg test sample (denoted as M).
Example:
If sieve analysis yields 22.2% (40–25 mm), 28.5% (25–16 mm), and 15.7% (16–10 mm), the 15 kg test mix includes:
- 5.02 kg of 40–25 mm
- 6.44 kg of 25–16 mm
- 3.56 kg of 16–10 mm
6. Tumbler Test Execution
Place the prepared sample into a standard tumbler drum rotating at 25 ± 1 rpm for 200 revolutions.
7. Post-Test Sieving & Calculation
After tumbling, sieve the sample through a 6.3 mm square-hole screen using 30 reciprocating motions at 20 cycles per minute (stroke: 100–150 mm).
Weigh the +6.3 mm fraction (m).
Tumbler Index (T) = (m / M) × 100%
8. Quality Standards
- Qualified product: T ≥ 62.5%
- First-grade product: T ≥ 65.5%
Why This Matters for Modern Steel Plants
For operators of EAF-based short-process steel mills and continuous rolling lines, consistent sinter quality minimizes dust formation, improves reducibility, and stabilizes furnace burden permeability. Integrating reliable tumbler strength data into raw material acceptance protocols enhances process control—especially when feeding high-efficiency direct reduced iron (DRI) or hot briquetted iron (HBI) blends alongside sinter.
At our company, we design green, intelligent short-process steelmaking solutions and high-precision rolling mill systems that rely on stringent input material standards. Understanding and applying the sinter tumbler strength test method aligns with global best practices in sustainable steel production, energy-saving smelting, and smart manufacturing.