What Raw Materials Are Used in Fertilizer Production?

Fertilizers are vital for helping plants and crops grow. But have you ever wondered what ingredients go into making modern fertilizers?

As it turns out, fertilizer production relies on a variety of raw materials derived from mineral deposits, hydrocarbon sources, industrial byproducts, and more.

In this complete guide, as a professional fertilizer production line manufacturer, I’ll give you an in-depth look at the key raw materials used to produce nitrogen, phosphorus, and potassium fertilizers.

Why Fertilizers Are Important

Before jumping into the raw materials, it helps to understand why fertilizers play such a crucial role in agriculture and food production.

As plants grow, they absorb nutrients from the soil. Key nutrients plants need include:

• Nitrogen – For green, leafy growth
• Phosphorus – To form roots, stems, and fruit
• Potassium – To build cell structure and improve drought resistance

Over time, these nutrients get depleted from the soil through erosion, leaching, and absorption by plants. As nutrient levels drop, plants won’t grow as vigorously or produce as plentiful of a harvest.

That’s where fertilizers come in. Fertilizers replace depleted soil nutrients, acting as a plant “vitamin shot”.

On average, 30-50% of crop yields depend directly on fertilizer nutrition. So without fertilizers helping augment the soil, the global food supply would take a significant hit.

What Raw Materials Are Used in Fertilizer Production?

The Core Ingredients: Nitrogen, Phosphorus, and Potassium

The three primary nutrients in fertilizers are nitrogen (N), phosphorus (P), and potassium (K). That’s why you often see fertilizers labeled with a combination “N-P-K” percentage.

For example, a 10-15-30 fertilizer contains:

• 10% nitrogen
• 15% phosphorus (in the form of P2O5)
• 30% potassium (in the form of K2O)

This N-P-K ratio is tailored to give plants a nutritional balance of each key ingredient.

But where do these core fertilizer ingredients actually come from? Let’s take a closer look at the raw materials behind nitrogen, phosphorus, and potassium fertilizers.

Nitrogen Fertilizer Raw Materials

Nitrogen is a critical component of proteins and growth hormones in plants. As such, it’s required in greater quantities than other nutrients.

The Haber-Bosch process, invented in the early 1900s, enabled mass production of nitrogen fertilizer. It works by combining nitrogen gas from the atmosphere with hydrogen derived from natural gas or methane.

Specifically, here’s a quick rundown:

1. Nitrogen and hydrogen gases are piped into a high-pressure reactor vessel along with a metal catalyst.
2. Bonding occurs between the hydrogen and nitrogen gases to produce ammonia (NH3).
3. The hot ammonia gas is cooled, causing it to liquefy.
4. Trace elements are removed to purify the ammonia.
5. Finally, the liquid ammonia is stored under pressure before going to downstream plants for conversion into nitrogen fertilizers like urea and ammonium nitrate.

So in summary, the raw materials are:

• Atmospheric Nitrogen – Sourced from air
• Hydrogen – Mainly from natural gas or methane
• Iron Catalyst – Improves ammonia synthesis reaction speed/efficiency

This ammonia then provides the base nitrogen that’s formulated into various end-use nitrogen fertilizers.

Phosphorus Fertilizer Raw Materials

The second key plant nutrient in fertilizers is phosphorus (P).

Found in critical growth compounds like DNA, phosphorus helps plants develop healthy root systems and postpone maturity. It also aids in seed production and fruit ripening.

Phosphorus fertilizers originate from phosphate rock deposits:

• Sedimentary – Formed by fossilized marine life
• Igneous – Created when molten lava containing phosphorus hardens

No matter the type of deposit, phosphate rock contains 12-17% phosphorus.

To unlock this, phosphate rock undergoes mining, beneficiation, and chemical processing:

1. Surface deposits are strip mined.
2. Phosphate ore is crushed and washed to remove impurities in a process called beneficiation. This leaves a phosphate-enriched powder.
3. The powder is treated with sulfuric acid, which separates out a phosphorus nutrient solution called green phosphoric acid.
4. Ammonia, sulfuric acid, or nitric acid is then added to the phosphoric acid solution to produce concentrated phosphorus fertilizers like triple superphosphate and diammonium phosphate.

So the raw materials behind phosphorus fertilizers includes:

• Phosphate Rock
• Sulfuric Acid – For processing ore
• Secondary Acids – Like nitric and sulfuric acid to create phosphorus compounds

That covers the key materials for synthesizing phosphorus fertilizers!

Potassium Fertilizer Raw Materials

The third primary nutrient, potassium (K), assists plants with building cell structure, water retention, and photosynthesis efficiency. It also helps fruits develop better color and flavor.

Potassium fertilizer raw materials mainly come from underground potassium salt deposits laid down by the evaporation of ancient inland seas.

Common production steps include:

1. Underground deposits of potassium salts like sylvinite are mined.
2. Raw potassium ore then goes through flotation, crystallization and purification processes. These form varieties like potassium chloride and potassium sulfate.
3. The potassium salts are next granulated to simplify handling and transportation.
4. Finally, chemical engineers blend them with other nutrient fertilizers at regional blending facilities.

So potassium fertilizer raw materials derive from mined potassium salt compounds like:

• Potassium Chloride
• Potassium Sulfate

Those are the origins of the “K” nutrients in your standard N-P-K fertilizer mix!

Secondary Nutrients & Trace Elements

While they make up a smaller composition percentage, secondary nutrients and micronutrients play an equally vital role in fertilizers.

Let’s do a quick review of where these origin from.

Secondary Nutrient Raw Materials

Secondary macronutrients represent about 5% of a typical fertilizer blend. Common secondary nutrients consist of:

• Calcium – Assists cell wall formation
• Magnesium – Found in chlorophyll
• Sulfur – Protein synthesis

These mainly originate from:

Limestone: Made up of calcium carbonate & calcium magnesium carbonate
Dolomite: Provides magnesium
Elemental Sulfur: Direct sulfur source

Micronutrient Raw Materials

While only making up around 1% of blends, micronutrients serve as essential cofactors driving plant enzyme activity and protein synthesis.

Micronutrients consist of boron, chlorine, copper, iron, manganese, molybdenum, nickel and zinc.

The raw materials derive from supplementing:

• Mineral ores like hematite
• Industrial metal byproducts
• Naturally concentrated trace mineral sources

That covers the common secondary nutrient and micronutrient raw materials blended into fertilizers!

Other Key Ingredients & Materials

Aside from the key macro/micronutrients already outlined, fertilizer production also relies on a few additional materials, including:

Binders & Fillers

Unreactive fillers make fertilizers easier to apply as a dust-free solid. Binders also minimize moisture absorption in storage.

Typical fillers consist of limestone, lignite, and iron sulfate. Natural fossilized phosphate, gypsum, and potassium magnesium sulfate also find use.

Coatings

Controlled release coatings serve an important role in granular fertilizers. These protective polymer layers regulate the speed of nutrient dissolution based on soil moisture and temperature. The objective is keeping nutrients available over a sustained period.

Polymer types often consist of plastic resins combined with sulfur, synthetic rubber, or vegetable oils. This tailors coating durability depending on the desired release rate.

Anti-Caking Agents

As granular fertilizers sit in storage, moisture and pressure can cause clumping. Anti-caking compounds prevent this through stabilizing agents, coatings, or crystal size/shape manipulation.

Common anti-caking materials consist of stearates, shale, gypsum, diatomaceous earths, silicas, and other crumbling minerals. These non-reactive substances separate fertilizer granules.

That sums up some other essential ingredients that enable efficient fertilizer production and handling!

The Bottom Line

• The main raw materials for fertilizer production consist of nitrogen compounds, phosphates, and potassium salts providing primary macronutrients.
• These originate from sources like phosphate rock mining, atmospheric separation, and extensive chemical processing and synthesis.
• Secondary nutrients and micronutrients represent a smaller but equally critical component supporting plant development, enzyme function, and stress tolerance.
• Additional raw materials like mineral fillers, polymer coatings, anti-caking additives play a role improving production, handling, and nutrient release characteristics.

So while the farming field is where fertilizers demonstrate their invaluable impact, it takes a vast industry harnessing resources globally to deliver the essential plant nutrients improving harvests.

Now that you know the raw materials backbone enabling fertilizers, you can better appreciate the science powering our food production system!