RECOVERY OF SOME ELEMENTS FROM SOLID WASTE PRODUCED FROM FUEL COMBUSTION IN POWER PLANTS

Document Type : Review Article

Authors

1 Egyptian Electricity Holding Company, Cairo, Egypt

2 Faculty of Graduate Studies and Environmental Research, Ain Shams University, Egypt.

Abstract

Solid waste residue generated in power stations that use heavy oil as the source of fuel poses a threat to the environment due to the presence of some heavy metals. At the same time, these metals include Vanadium (V) and Nickel (Ni) can be recovered and recycled. In this work Vanadium and nickel were recovered from solid waste residue (Furnace Bottom Sediments FBS) collected from the bottom of steam boiler. Four samples were selected and collected from different boilers. Solid samples were grinded to convert them to powdered form and sieved in 200 micrometer. The grinded samples were used for recovery. The recovery of vanadium and nickel was conducted in two stages. A first stage was acidification of the grinded (FBS) using 30 % sulfuric acid (dissolution of FBS) followed by alkali metal precipitation. The second stage is similar to first stage on the remaining solids from first stage. Determination of vanadium and nickel were conducted by two techniques, Energy Dispersive X-ray(EDX) and Inductive Coupled Plasma (ICP technique) .The effect of some operational parameters (liquid/solid, leaching, temperature, mixing time, acid and alkali concentrations) on the recovery of V and Ni was investigated. Conditions of precipitation of V and Ni from alkali solutions were established. The effect of different amount of ammonium hydroxide/ammonium chloride which gives deferent pH value from (2 to 10) at different temperatures (25, 40, 60, and 80 ºC) were investigated. The maximum recovery of vanadium reached 96.3% at (pH 3.5), Nickel recovery was 95.8% at (pH 9.5) for reaction time 4 h.
 

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