ROP Single Superphosphate and Triplesuperphosphate

Features

• Turbine mixers-belt dens have been used to produce SSP/TSP with both igneous and sedimentary phosphate rocks since the 1950's
• Designs are available from 10 to 130 tph.
• Operations since 1984 with direct dilution of the 98% H₂SO₄ with either water or H₂SiF_6.
• No liquid effluents when using dilution with H₂SiF₆.
• The turbine mixer-belt den combination produces a low density, porous product, that is easy to granulate.
• Permits operation with rock slimes or ground phosphate rock in the form of slurry with the H₂SiF₆ from the scrubbing system. This option uses 98% H₂SO₄ in a special mixing head and is only available for SSP production.

The Process

The process involves the grinding of the phosphate rock either in a dry ball mill or ring roller mill to meet the following size specification:

Sedimentary phosphate rocks: 80 - 85% passing Tyler 200 mesh.

Igneous phosphate rocks: 80 - 85% passing Tyler 325 mesh.

The ground rock is weighed on a continuous belt-weigher and fed into the turbine mixer.

The rock feed controls both the H₂SO₄ concentration and mass by means of a ratio controller. (Or the H₃PO₄ concentration and mass by means of a ratio controller in the case of TSP).

The degree of agitation and residence time in the turbine mixer is controlled by the speed of rotation of the mixer. The mixer has 3 sets of 4 blades. The reactor and mixer blades are treated with a resin coating to increase their resistance to corrosion and abrasion.

The reacting mass of SSP/or TSP is discharged from the turbine mixer onto the enclosed belt den, which has a residence time of 6 - 10 minutes. There is a low HP cutter located at the end of the den, which helps to break up the material before being dispatched to the store for "curing".

There are several gas exhaust points on the belt den, including the cutter housing and the first stage of the conveyor belt to the storage box.

The gases from the den are washed in a three-stage Venturi scrubbing system, which produces a dilute solution of H₂SiF₆. This can be used to dilute the H₂SO₄ or H₃PO₄ or filtered and sold for water treatment.

JSA Turbine Mixer Features

The JSA Turbine Mixer has been used in five installations in Brazil. The JSA Turbine Mixer has the following features:

• Can be used to produce SSP/TSP with both igneous and sedimentary phosphates.
• Designs available from 10 to 130 tph.
• The turbine mixer - belt den combination produces a low density, porous product, that is easy to granulate.

JSA Turbine Mixer Reference List