We offer a complete end-to-end process solution for the production of sulphur bentonite fertilizer, starting from raw materials handling and the mixing of liquid sulphur and bentonite, through solidification on our proven Rotoform granulation system, to storage, weighing and bagging.

Meeting a global agricultural demand for sulphur

Global demand for sulphur for agricultural use has grown rapidly in recent years. However, elemental sulphur cannot be used as nutrient, mainly because it is not soluble in water.

One solution is to combine elemental sulphur with bentonite, a type of clay that increases its volume by factor of 3 to 5 when it comes into contact with water.

When a sulphur bentonite granule comes into contact with soil moisture, it breaks apart into fragments of dust-size particles, thus allowing swift and continuous solubilisation.

Upstream sulphur bentonite mixing solutions

We supply a range of upstream solutions including blending and grinding units. These can be used to combine liquid and solid products into suspensions, enabling the production of sulphur bentonite and many other speciality fertilizer products.

Rotoform solidification

Granulation takes place on the Sandvik Rotoform system. This consists of a heated, cylindrical stator and a perforated rotating shell that deposits molten droplets onto a continuously running steel belt.

The circumferential speed of the rotating shell is synchronised with the speed of the belt: drops are therefore deposited without deformation. Heat released during solidification and cooling is transferred by the stainless steel belt to cooling water sprayed against the belt underside. This water is collected in tanks and returned to the recooling plant; at no stage does it come into contact with the sulphur.

Advantages of the Rotoform process for sulphur bentonite

  • Product quality – uniform shaped pastille due to Rotoform process
  • Solidification 
- well defined cooling time
  • Heat transfer 
- indirect, no contact between product and cooling medium
  • Flexibility – rapid changeover to partial operation without changes in quality; modular design means each unit can be operated individually
  • Environmentally friendly – dust, H2S and SO2 content are all within internationally accepted limits

Low utility costs

  • Low power consumption
  • Low water consumption due to recooling system
  • Low compressed air and instrument air consumption
  • Low steam consumption

Easy maintenance and reliable operation

  • Fully-automatic operation (except start-up which is manual for safety reasons)
  • Easy maintenance and operation
  • Essential components accessible from the floor without auxiliary equipment
  • Few, light and easily mountable spare parts
  • Quick start-up of plant for reduced downtime

Handling of sulphur bentonite pastilles

We have the know-how and experience needed to design, manufacture and commission complete handling installations, tailor-made to the requirements of each client.

  • Systems for the transportation of pastilles, i.e. conveyor belts, inclined conveyors and bucket elevators
  • Silos including filling and discharging devices
  • Weighing and bagging systems for different types of bags (25, 50, 500, 1000 kg)
  • Control systems