Salt Refining Process Description

The Raw Salt will be loaded to the hopper through which it will enter the Special Washing System. The flow rate will be measured here and controlled to set it as per the pre-decided rate based on the purity of raw salt. In the Screw Washery, the major portion of the impurities will be removed. The washed salt will enter the wet Mill Section (Grinding/ Hammer Mill). The brine is added here to give slurry output from the mill. The output is tanked into a slurry tank where further brine is added. The slurry is then pumped to the Elutriation tank for washing. The washed slurry is then transferred to Thickener and decanted brine is transferred to the clarifier by means of Elutriation & wash tank. From here the clear brine is transferred to the brine tank and remaining to the settling pond. Here at settling pond, the settled mud is drained and the upper layer of clear brine is pumped to the Screw Washery. The Salt after removal of water in Thickener is fed to the Centrifuge. In Thickener, the slurry concentration achieved is 50%.

The salt will then be centrifuged to liquid form and it Will be conveyed through the blender cum screw conveyor and belt to fluidized bed dryer. On its way to dryer, it will be iodized.

The washed salt with Iodine Solution will get fluidized in Dryer and Iodine mixing will uniform. Then dry and cooled salt Will travel to Vibro screen through bucket elevator.

After screening, the undersize will be conveyed to a blender cum screw conveyor. Here the Free Flow Agent will be mixed at a specified and predetermined flow rate.

The blender cum conveyor will mix the content well and convey the same to a silo. The finished goods from the silo bottom will be conveyed and distributed by a screw conveyor to Packing Machines. Then the pouches of 1.0 Kg. will be sealed. Another conveyor will carry the refined salt to the bagging and stitching machine where it will be packed in 50Kg bags.

Specification

PROCESS OF THE PLANT

Raw salt is sent to a feed hopper at appropriate capacity and then transferred to a conveyor band.

A magnet is used to remove trash metals from this conveyor.

Raw salt is washed in a special washing system.

Crude salt is ground in a wet grinding system with a saturated brine.

Salt slurry is sent to a tank and pumped to a washing tank with one of centrifugal, high-pressure pump, centrifugal pump, axial flow pumps or gear pump.

Slurry is removed from slurry in washing tank.

Saltwater overflowing from washing tank is recycled.

Salt slurry is sent to hydrocyclone to thicken it.

Salt is removed from water in large scale by centrifugation. Iodine dosing is made.

In the fluidized bed dryer, salt is completely dried.

Drying milling is done to thin clumping salts.

Salts are passed through a screening machine to be classified.

If tablet salt production will be carried out, fine grade salt is sent to the rotary tablet machine.

FEATURES OF THE PLANT

For less salt loss, washing process is carried out in conjunction with countercurrent washing technology.
Iodine or other additives are added according to customer needs.
After drying, screening process is applied to classify granules in different sizes.