Granulated Single Super sulphate Plant

The granulated SSP is produced by granulation of SSP in the granulation plant. The granulation is done because the nutrients remain available for a longer time. The granule releases the nutrients very slowly. This process improves the nutrient utilization.

RAW MATERIALS AND THEIR RESOURCES :
The raw materials for manufacturing SSP are as follows:

• ROCK PHOSPHATE: Rock phosphate is mined in many countries like India, China, Israel, Jordan, Syria, Morocco, Egypt, Malaysia, Indonesia and many African & American countries. The 31% plus grade is suitable for the production
• SULPHURIC ACID: The technical grade Sulfuric acid that is 98.5% pure is suitable for the process. However spent sulfuric acid from other industries like textiles, Detergent and which is a waste, can also be used along with the technical grade sulfuric acid in the plants designed by us.
• FUEL: To dry GSSP any fuel like Furnace Oil, H.S. Diesel, LDO etc may be used.
• FILLERS: Gypsum, Sand etc.

PROCESS OF MANUFACTURING :
The Rock phosphate brought from the mines is stored in rock storage shade. This is very important because it is very difficult to ground wet Rock phosphate. If the Rock Phosphate is received wet, first of all it has to be dried with the help of Rock dryer. The rock dryer contains a drum connected with a Hot air generator and cyclone with ID fan & scrubber. The dried Rock is fed to a Ball Mill to grind it to -100 mesh (90%). The ground Rock is stored in the Ground Rock hopper. The Sulfuric acid received from the manufacturer is stored in the Sulfuric acid storage tanks. The special lined tank may be used for the spent acid storage.

The reaction between the raw materials takes place in the mixer. The mixer is a vessel with acid and heat resistant lining. The ground Rock Phosphate is controlled, weighed and fed to the mixer with the help of rotary airlocks, screw conveyors and elevator. The Sulfuric acid is pumped, controlled, measured and fed into the mixer with the help of pumps, pipelines, Rotameter and valves. The mixed material is kneaded for some time and dumped into a Den. The den is a enclosed, acid & heat resistant lined and slow moving conveyor. The materials keep on reacting for about an hour. The mixer and den are connected to an ID Fan through the scrubbers to scrub the emitted gases. The mixed material which was a free flowing slurry in the mixer becomes a semi solid in the den and becomes a cake at the discharge end of the den. At the discharge end of the den the cake is disintegrated by den cutter. The reaction is very fast and exothermic. The reaction rate depends on many parameters but most importantly it depends on the origin of rock Phosphate.

The material is discharged from the den and it is heaped in the green SSP shade with the help of an Electric Overhead Travel Crane. The reaction continues in the heap and it may complete in 5 days to 21 days. This period depends entirely on the origin of Rock Phosphate as the reactivity of the rock is related to its origin. The heaps are regularly monitored and as soon as the material is cured it is shifted for manufacturing either GSSP The reaction between the rock phosphate and acid is called as acidulation & proceeds with the emission of Fluorine based gases. These gases are scrubbed by the state of the art Ventury scrubbers which have 90 - 95% efficiency, convert the gases into Hydro Fluoro Silicic Acid. and Silica. The Hydro Fluoro Silicic Acid is recycled back into the Mixer. The silica formed is used as a filler in PSSP & GSSP manufacture. So a zero effluent system is used.

PROPERTIES OF SINGLE SUPER PHOSPHATE :
Nature:

1. Free flowing powder and Granules Grayish to brownish white angle of repose 36O slight Hygroscopic / Caking at long storage acidic in nature, stored in dry place

Quality Specifications :

1. Powder SSP(Green super phosphate)
   1. Moisture Contents Max 12%
   2. Free Acidity Max 4%
   3. Water Soluble P2O5 Min 16

PROCESS OF MANUFACTURING OF GRANULATED SINGLE SUPER PHOSPHATE :The measured quantity of the cured SSP is mixed properly with filler in a mixer. The homogeneous mass is then processed in the granulator drum.. The granulator drum rotates at very low RPM. The material goes up with the wall of granulator for some height and then starts rolling back. A fine spray of water at this stage starts the process of granulation and as the material rolls on, the size of the granules increases. This material is transferred to the dryer drum with the help of a conveyor belt. The Furnace attached to the dryer generates hot air which is made to pass through this wet material. The evaporation & condensation of water gets deposited on the small granules and further enhance the size of the granules. With the hot air stream the material gets dried. The material is then passed through the cooler drum for cooling. The cooled material is transferred to the screens to remove the oversize & undersize granules from the product. The oversize granules after crushing & under size granule are mixed with the raw feed for reprocessing. The plant is equipped to deal with air pollution inside the plant and stack flue gases.
The product is packed in 50 Kg bags.

Granulated SSP(GSSP)

• Moisture Contents Max 6%
• Free Acidity Max 4%
• Water Soluble P2O5 Min 16%
• Granule Size ( 1-4 mm) Min 90%