At the Trombay (RCF) complex, nitrophosphate is manufactured. In fertilizer classification, nitrophosphate is best described as which type of fertilizer?

Introduction / Context:
Nitrophosphate processes (e.g., Odda) produce fertilizers containing both nitrogen and phosphorus in chemically combined forms. Unlike simple blends, complex fertilizers have nutrients present as part of the same granule through chemical reactions, improving uniformity of nutrient distribution and handling characteristics.

Given Data / Assumptions:

• Nitrophosphate is produced by reacting phosphate rock with nitric acid, followed by neutralization and finishing.
• Product contains N and P; potassium may be added to make NPK complexes.
• Terminology: “mixed” implies physical blending; “complex” implies chemical combination within a single product matrix.

Concept / Approach:
Because nitrophosphate nutrients are generated by chemical reaction and incorporated in each particle, the product is a complex fertilizer. While any fertilizer may exhibit some hygroscopicity, “highly hygroscopic” is not the defining class, and “highly explosive” is incorrect for finished nitrophosphate products managed under normal fertilizer safety protocols.

Step-by-Step Solution:
Identify production route: nitric acid digestion of rock phosphate.Recognize nutrient incorporation into particle matrix.Differentiate complex vs mixed: chemical vs physical mixing.Select “complex fertilizer.”

Verification / Alternative check:
Fertilizer manuals classify nitrophosphates among complex N–P or N–P–K fertilizers based on chemical manufacture rather than physical blending.

Why Other Options Are Wrong:
Mixed: implies blend of separate nutrient salts, not chemically co-produced.Highly hygroscopic: property, not a type.Highly explosive: not an attribute of finished nitrophosphate fertilizers.

Common Pitfalls:
Confusing “nitro” in the name with explosives; equating any multi-nutrient fertilizer with a “mixed” product regardless of manufacturing route.

Final Answer:
Complex fertilizer