Phosphatic fertilizer manufacturing: Which constituent of phosphate rock is the primary pollutant of concern due to emissions released during processing?

Introduction:
Processing phosphate rock can release gaseous pollutants. Identifying the key contaminant helps target emission control systems.

Given Data / Assumptions:

• Phosphatic fertilizer plant using phosphate rock.
• Looking for the pollutant of primary interest.
• Typical wet-process phosphoric acid or superphosphate context.

Concept / Approach:
Phosphate rock frequently contains fluorine. During acidulation, volatile fluorine compounds such as HF and SiF4 can be emitted unless scrubbed.

Step-by-Step Solution:
Step 1: Recognize fluorine content in many phosphate ores.Step 2: Acid treatment liberates fluoride gases.Step 3: Therefore, fluorine compounds are the primary pollutant concern.

Verification / Alternative check:
Plants install wet scrubbers to capture fluoride emissions and protect workers and nearby communities.

Why Other Options Are Wrong:
Calcium and phosphorus are product-related, not the main emitted pollutants; sulfur and silica behave differently and are not the chief gaseous emissions of concern here.

Common Pitfalls:
Assuming phosphorus itself is the key air pollutant; it is largely retained in the product stream.

Final Answer:
Fluorine