Froth flotation of carbon from fly ash using environmentally friendly oil/method of removing carbon from fly ash

Robert Styron

A froth flotation method is provided for removing carbon from fly ash which utilizes an environmental friendly conditioning agent. The conditioning agent preferably comprises a biodegradable oil which is added to a slurry containing raw fly ash and water. The conditioning agent renders the carbon in the fly ash hydrophobic such that upon aeration of the slurry, air bubbles attach to the carbon particles and carry them to the surface of the slurry in the form of a froth, such that the carbon may be removed.

Removal of ammonia from fly ash

Jiann-Yang (Jim) Hwang

A method for removing ammonia and ammonia compounds from fly ash and other combustion by-products is provided. The method may be performed with raw or processed fly ash, or it may be performed in conjunction with a wet beneficiation process. The method involves mixing the ammonia-contaminated fly ash with water and then filtering and/or drying the solution to remove the ammonia and water. The method produces fly ash having an ammonia content of less than about 60-80 ppm, which allows the fly ash to be utilized in a number of applications.

Wet process for fly ash beneficiation

Xiaoqiu Huang

A wet process for the beneficiation of a fly ash by-product has the following steps: a) forming a slurry mixture of a fly ash material and a liquid; b) gravitationally separating and collecting a first material fraction of the fly ash having a density less than the liquid by skimming off floating slurry material; c) separating a first magnetic fraction from the slurry by subjecting a first magnetic fraction from the slurry by subjecting the slurry to a magnetic field of from about 300 gauss to about 10 kilogauss; d) separating the unburned carbon from the remaining slurry components by adding an effective amount of an oil having a carbon chain greater than octane, and a frothing agent whereby the oil coats the unburned carbon forming hydrophobic carbon materials and inducing air into the system for frothing the slurry mixture wherein the hydrophobic unburned carbon froths to the surface and is removed by skimming off the frothing layer; and e) collecting the remaining fraction of silicate spheres and silicates.

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