Fluidized Bed Acid Regeneration Plants

Our fluidized bed acid regeneration plants recover bound and unbound chlorides from metal chloride solutions as azeotrope HCl at 18% strength. Metals contained in the feed solution are oxidized and separated as metal oxide powder.
Applications of this technology include:

	spent pickle liquor regeneration
	nickel oxide production
	titanium dioxide production

Metal oxides produces by fluidized bed technology are of coarse, granular consistency with spherical shape and average grain diameters of approximately 1-2 mm. In case of ferric oxide the bulk density is about 3.5 kg per liter.
While the fluidized bed process consumes significantly more energy (+50%) than a comparable spray roaster operation, the dust free nature of its by-product, which permits easy, compact storage, simplified transportation and convenient feeding to downstream metallurgical operations (such as iron ore sinter plants) is widely regarded a significant operational advantage.

Similar to spray roaster acid regeneration the core chemical conversion step performed inside a fluidized bed hydrochloric acid regeneration plant is pyrohydrolysis. For spent pickle liquors the reaction equations are given as:

Those reactions happen inside the directly fired fluidized bed furnace at temperatures between 850 and 950 degrees Celsius, depending on feed composition and furnace operating mode. Oxide retention time is several hours. This yields oxides with ultra-low residual chlorine content but also very low specific surface areas. Suitable fuels include:

	natural gas
	city gas
	propane or petroleum gas (LPG)
	coke oven gas
	mixed gas from coking and steel making
	liquified natural gas (LNG)

Fluidized Bed Acid Regeneration Plants for the carbon steel industry can be designed for treatment capacities between 500 and 25.000 liters per hour. Larger treatment capacities require parallel arrangements of more than one plant. Compared to spray roaster plants their reactors operate at higher temperature and have to withstand higher abrasive forces resulting in comparably higher operating and maintenance cost.

Fluidized Bed Acid Regeneration Plants produce only minor quantities of NOx emissions. This makes them a sensible choice in locations where regulatory NOx limits are severe.

Process Characteristics

Furnace Operating Principle