Sulphitation with Bentonite A process employing colloidal bentonite combined with sulphitation was developed in Argentina for the production of direct-consumption white sugars, especially with juices of deteriorated or frozen cane. Bentonite is a clay, and the material selected is sold in Argentina under the trade name Clarigel . The advantages claimed are lower sulphur and lime consumption, much greater removal of organic non-sugars, better boiling properties of syrups and molasses because of reduced viscosities, and less scaling of evaporators. The production of SO 2 occurs when sulphur is burned in a current of air. In any type of sulphur burner the air supplied to the furnace should be dry, because moisture in the air will cause the formation of sulphuric acid, obviously detrimental to piping, and soon, and can be especially serious if it reaches the juice.
Mechanical feed ensures continuous operation.
The sulphur melts by its own heat of combustion in the rotating cylinder, presenting a large surface for combustion as the sulphur drips through the air. There are new methods of SO 2 generation. It is normally operated at 2.0-3.0 psig, but can also function effectively at 42 psig. A typical flow scheme for a modern SO 2 generation plant is given Liquid Sulphur Dioxide Where transportation costs will permit, liquid SO 2 offers many advantages. MeGinnis diagrams a system for the introduction of liquid SO 2 .