Testing that Reaches the World
Clark Laboratories | CRI and CSR Testing
Analysis for Quality, Environmental Compliance, and Commercial Value
What are CRI and CSR Tests?
CRI (Coke Reactivity Index) and CSR (Coke Strength After Reaction) are critical metallurgical coke quality indicators used throughout the steel industry.
These tests evaluate how coke behaves inside a blast furnace under high-temperature operating conditions.
Coke Reactivity Index (CRI)
CRI measures the tendency of coke to react with carbon dioxide at elevated temperatures.
Lower CRI values generally indicate:
- Better coke stability
- Improved furnace performance
- Reduced coke consumption
Coke Strength After Reaction (CSR)
CSR measures the physical strength of coke after exposure to high-temperature reaction conditions.
Higher CSR values indicate:
- Greater structural integrity
- Improved blast furnace support
- Better permeability
- Increased productivity
Why CRI/CSR Testing Matters
Steel producers use CRI and CSR results to:
- Evaluate coke quality
- Improve furnace efficiency
- Reduce operating costs
- Enhance iron production rates
These tests are among the most important quality metrics for metallurgical coke producers worldwide.
› Proximate Analysis Testing
Fuel quality analysis including moisture, ash, volatile matter, and fixed carbon.
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› Sulfur Analysis Testing
Sulfur testing for emissions compliance and product specification verification.
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› Ultimate Analysis Testing
Elemental analysis of carbon, hydrogen, nitrogen, sulfur, and oxygen.
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› BTU & Calorific Value Testing
Measure energy content for fuel valuation and combustion performance.
Why Choose Clark Testing for CRI & CSR Testing?
For more than three decades, Clark Testing has provided independent coal, coke, and fuel testing services to industrial customers throughout North America. Our laboratory understands the critical role metallurgical coke quality plays in blast furnace performance, iron production efficiency, and overall steelmaking operations.
CRI and CSR testing provide essential insight into how coke will perform under the extreme conditions encountered within a blast furnace. Accurate, reliable results help producers, suppliers, and end users evaluate coke quality, optimize furnace operations, and support commercial quality specifications.
Clark Testing performs metallurgical coke testing using recognized industry methodologies, delivering dependable data that supports operational decision-making, product certification, quality assurance, and commercial transactions.
Clark Testing Advantages
- Independent Third-Party Laboratory
- Experienced Coal and Coke Specialists
- Metallurgical Coke Testing Expertise
- Fast Turnaround Times
- Quality Assurance and Product Verification
- Commercial Transaction Support
- Reliable Analytical Results
- Responsive Technical Service
Whether you are evaluating blast furnace coke quality, verifying supplier specifications, supporting steel production operations, or monitoring product consistency, Clark Testing provides the trusted CRI and CSR data needed to support performance, productivity, and operational success.
› Hardgrove Grindability Testing
Evaluate grindability to optimize milling and fuel handling.
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› CRI and CSR Testing
Assess coke reactivity and strength for blast furnace optimization.
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› Ash Fusion Testing
Determine ash melting behavior and slagging potential.
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› Trace Metals Analysis
Analyze nickel, vanadium, mercury, and other trace elements.
Need Petroleum Coke Testing?
Request a quote or speak with a Clark Testing specialist about your project.

