A process for magnetization of fly ash for use as soil conditioner Field of the Invention:

This invention relates to the field of disposal of fly ash generated in thermal power plants and more particularly to the largely small field of adding economic value to fly ash by use as a soil conditioner.

Background of the Invention:

There are volumes published on disposal of fly ash and adding economic value to fly ash by its use in manufacture of cement and ceramics.

However, scale of this utility is insignificant and confined to small field, compared to the one at which fly ash is generated, posing ever-increasing challenge of balancing land conservation with fly ash disposal. The conventional methods of using fly ash as landfills do not complete the cycle of returning to earth what is extracted out from the earth as coal. The centuries of this continuing practice has rendered millions of acres of land devastated by this imbalance.

There is a sole prior work of art in the field, cited below for comparison with the present invention and drawing out drawbacks, if any, in the prior work. US Patent 3,536,198 - This prior work magnetizes fly ash agglomerates in liquids to convert them into larger agglomerates for easier separation from liquids, employing magnetic field of 800 gauss at centre of a pipeline for a residence time of one twentieth of a second. There is a difference to state of fly ash material between the prior work cited and the present inventions. The former relates to fly ash agglomerates being suspended in flowing liquids. The present invention relates to magnetizing dry ash.

The cited work employs magnetization for the sole objective of facilitating agglomeration of suspended solids. The cited prior work shares no similarities with the present invention.

There are no other prior works found registered or pending registration. Objects of the Invention:

A primary object of the present invention is to devise a process for converting fly ash into soil conditioner to return to the earth what is taken out and extracted from the earth as coal.

Another object of the present invention is to enhance many-fold economic value of otherwise disposable fly ash. Another object of the present invention is to facilitate land management in terms of arresting land degradation and improving intake of fertilizers by plants and crops, quality and yield of crops per acre of cultivated land.

Another object of the present invention is to ease the disposal of gigantic quantities of fly ash generated by thermal power plants.

Another object of the present invention is to address the problem of the land imbalance, so widespread in coal-bearing regions of the world, where the earth stands denuded of its productive layers, supporting plants, trees and agriculture on the one hand and nothing capable of supporting biological processes and regenerating earth is returned to the earth on the other hand. The present invention aims to address the land imbalance problem on both fronts.

Summary of the Invention:

The present invention eliminates the drawbacks associated with the conventional methods for disposal, handling and storage of fly ash as explained hereunder.

A process for converting fly ash ^' generated in thermal power plants into soi l conditioner comprises following operations:

) collecting fly ash ( 10) into vehicle-mounted

containers of 10 ton or 20 ton capacity to avoid ground-level

contamination;

) reducing moisture of fly ash (10) by passing through an oven (20) heated to 55 degree C temperature to fly ash (15) with 4% - 5% by weight moisture content;

) passing fly ash ( 1 5) through a magnetizer (30) generating a magnetic field of 10,000 to 15,000 gauss such that the residence of the fly ash ( 15) during exposure to magnetic field is for 5 to 8 seconds.

) collecting magnetized fly ash (25) leaving the magnetizer (30) into

plurality of open pans (40) and cooling to ambient temperature as magnetized fly ash (100), ready for use as soil conditioner.

The present invention does not seek to treat fly ash by adding storage and transportation operations for handling fly ash, as carried out with the conventional fly ash disposal procedures. It, instead, works like an extension of thermal power plant by employing the magnetizer in close vicinity of downstream end of electrostatic precipitator. Description of Drawings:

Drawing # 1 i llustrates flow sheet for handling and magnetization of fly ash

Drawing # 2 illustrates cross sectional side view of the magnetizer (30). Drawing # 3 illustrates cross sectional elevation view of magnetizer (30).

Detailed Description of the Invention:

Fly ash chemically consists of silica, alumina, iron oxides (ferrous and ferric) and trace elements such as calcium, magnesium, potassium, sodium and titanium. Fly ash. upon being subjected to controlled magnetic field, exhibits remarkable magnetic movement. This magnetic movement causes nutrients in soil to be attracted to roots of plants, facilitating assimilation of the nutrients in the soil - to which magnetized fly ash is added - by the plants.

Fly ash (10) discharged from electrostatic precipitator of thermal power plant directly must be collected into 10 tonne or 20 tonne container (50) without being dropped on ground. Contamination of the fly ash ( 10) at ground level conditions renders it unsuitable for magnetization.

Containers (50), mounted on vehicles, are unloaded by means of a screw conveyor (40) into plurality of pans (22) of hot air oven (20). The oven (20) is maintained at 55°C temperature to reduce moisture content of fly ash ( 10) to dried fly ash ( 1 5) with moisture content of 4-5% by weight. Electrical conductivity of fly ash ( 10) being dried in hot air oven (20) is monitored and should not fall below 0.25 dsm ^{" 1} unit. First inventive feature of the present invention is to pass in vertical direction dried fly ash (15) through a magnetizer (30) under controlled conditions to impart permanently magnetic activity to the dried fly ash (15).

The second inventive feature of the present invention is to devise controlled conditions, conducive to imparting magnetic activity to fly ash - namely eliminating ground level contamination of fly ash, reducing moisture content to 4% - 5% by weight by drying fly ash (10) at 55 °C temperature, monitoring electrical conductivity during drying operation, subjecting dried fly ash to magnetic field of 10,000 to 15,000 gauss and controlling residence time of dried fly ash (15) inside the magnetizer (30) to 5 - 8 seconds by means of feed valve (28), situated on upstream end of the magnetizer (30).

Dried fly ash ( 1 5) is fed vertically tQ mouth of magnetizer (30), which is cylindrical in shape and is made of twin coaxial chambers (31 , 32), as illustrated in the accompanying drawings # 2 and # 3. The inner chamber

(31 ) has an internal diameter of 600 mm and the outer cylindrical chamber

(32) has an internal diameter of 1200 mm. The dried fly ash ( 15) passes through the inner chamber (31 ). The outer cylindrical chamber (32) radially is fitted with nine rows of coil (33). each coi l being capable of conducting 240 V D.C. power of 60 amperes rating. Each coil (33) is wound around pole piece (34) of iron core. The inner cylindrical chamber (31 ) exteriorly is fitted with fixed coil sextupole (35), as illustrated in the accompanying drawing # 2.

The magnetizer (30) is fitted with an automatic lead (37) of stainless steel construction, ahead of the nine rows of coil (33). The automatic lead (37) is electronically operated from control panel (42) for controlling passage of the dried fly ash ( 15) through the-magnetizer (30) such that the residence time of the dried fly ash inside the magnetizer (30) is 5-8 seconds.

Magnetized fly ash (25) leaving from the bottom end of the magnetizer (30) is collected into pans (40) through hopper 40A and discharge valve 40B, is cooled to ambient temperature. The cooled magnetized fly ash (100) is the ideal soil conditioner and is packed into 50 kg bags for end use.

Field trials were conducted using the magnetized fly ash ( 100) as a soil conditioner for use in conjunction with fertilizers. The magnetized fly ash ( 100) not only improved the yield and the quality of agricultural produce, but reduced the requirement for fertilizers. The filed trials are summarized in the table below.

Experiment - 1

To determine response of groundnut to levels of magnetized fly ash and NPK and their effects on soil properties.

Total no. of treatment: Eight

Crop Variety: SB XI

Spacing: 30cm X 15 cm

Plot size: 6.6m X 6.0m

Date of sowing - 17/08/2008

Date of Harvesting - 12/12/2008

Details of treatment:

A. Levels of magnetized fly ash

AO - No fly ash application

Al - 1000 kg MFA/ha

A2 - 2000 kg MFA/ha

A3 - 3000 kg MFA/ha

(MFA - Magnetized fly ash)

B. Levels of NPK

Fl - Recommended NPK doses (25:50:ONP /ha)

F2-3/4ofFl (18.75:37.5:0 kg NPK/ha) Results: -

I. Growth and yield of groundnut

The data (table) indicates beneficial effect of magnetized fly ash application with recommended NPK doses. It was observed that there 5. was more or less similar plant count in every treatment, however, application of 3 / 4 dose of fertilizer and

15000 kg of MFA / ha has given highest pod yield.

Table: 1

Best Method for Operating the Invention:

Following conditions ensure ideal working of the invention:

1 0. 1 . Fly ash should not be contaminated.

2. Electrical conductivity of dried fly ash should not be less than 0.25 dsm