How to Make Rock Phosphate Fertilizer

Rock phosphate fertilizer is an essential nutrient source for plants, particularly in organic farming systems where synthetic inputs are limited or prohibited. Rock phosphate, primarily composed of phosphorite, is a natural, slow-releasing source of phosphorus, which is crucial for plant growth, energy transfer, and reproduction. Here’s how to make rock phosphate fertilizer for agricultural use.

Understanding Rock Phosphate

Before making SPP granule fertilizer, it’s critical to understand that rock phosphate is not immediately available to plants. It is a mined material that contains phosphorus in a form that must be broken down by soil acidity and microbial processes before plants can absorb it. The effectiveness of rock phosphate as a fertilizer depends significantly on soil pH, with acidic soils (below pH 7) favoring faster breakdown and availability.

Rock phosphate as fertilizer
Rock phosphate as fertilizer

Sourcing Rock Phosphate

Rock phosphate is usually obtained from phosphate rock deposits. It’s vital to source high-quality rock phosphate with a good concentration of phosphorus. The ideal rock phosphate for fertilizer should have at least 28% phosphorus pentoxide (P2O5). You can purchase rock phosphate from gardening stores, agricultural supply stores, or directly from mining companies.

Making Rock Phosphate Fertilizer

Creating rock phosphate fertilizer is a process that transforms insoluble phosphate rock into a more plant-accessible form. Here is a concise guide on phosphate fertilizer making process

Rock Phosphate Crushing

Begin by crushing the mined rock phosphate into smaller particles. This increases its surface area, allowing for a more efficient chemical reaction. Use industrial crushers or hammer mills to crush the rock into a fine powder.

Mixing with Sulfuric Acid

Carefully combine the crushed rock phosphate with concentrated sulfuric acid in a controlled environment. This reaction produces phosphoric acid and gypsum, a byproduct. Ensure proper safety measures, including protective gear and equipment, are in place due to the corrosive nature of the chemicals involved.

Acidification and Aging

Allow the mixture to undergo acidification. During this phase, the chemical reaction continues as the mixture heats and releases fumes. The resulting slurry should be stored safely to age. This period allows the reactions to complete and the mixture to stabilize.

Granule Making

Once the slurry has aged and cooled, the next step is to convert it into a granular form. Use a SSP granulator machine to form uniform-sized granules, which are then dried to create the final rock phosphate fertilizer product. Click here for more details

After these steps, the rock phosphate fertilizer is ready to be packaged and distributed for agricultural use, ensuring that it meets safety and quality standards. Always follow environmental regulations and safety protocols throughout the process to minimize any potential risks to workers and the environment.

Rock phosphate fertilizer production equipment
Rock phosphate fertilizer production equipment

Rock phosphate powder using in organic Composting

When you make organic fertilizer, to make phosphate elements more readily available to plants, you can mix it into your compost pile. The organic matter and microorganisms within the compost can help break down the rock phosphate, making the phosphorus more accessible.

By following these steps and understanding the nature of rock phosphate, you can effectively make and use rock phosphate fertilizer to maintain the phosphorus levels in your soil and promote healthy plant growth or for commercial. If you need a precise plan for rock phosphate to SSP fertilizer, you can visit