Claims
- 1. A method for smelting fly ash to a leaching resistant slag while simultaneously being able to separate the content of heavy metals such as zinc and lead,
- characterized in that the fly ash is introduced into an oxidizing gas which has a temperature which is 2500.degree. C. or higher,
- and that there is added a carbon or hydrocarbonaceous substance which supplies additional energy to the process, thus bringing the fly ash to smelting point as drops of slag,
- that heavy metals such as zinc and lead are reduced, pass into the gas phase and are recovered in one or more subsequent stages as zinc and lead compounds in a dust from
- and that drops of slag are collected as liquid leaching resistant slag.
- 2. A method for smelting fly ash according to claim 1, characterized in that the oxidizing gas is passed through a plasma generator for heating.
- 3. A method for smelting fly ash according to claims 1, characterized in that the degree of oxidation of the gas is regulated in such a manner that the ratio CO.sub.2 /CO+CO.sub.2 is kept within the values 0.4-0.9 by regulating the supply of a carbon or hydrocarbonaceous material.
- 4. A method for smelting fly ash according to claim 3, characterized in that the degree of leaching of the slag formed is regulated by keeping the ratio CaO/SiO.sub.2 lower than 1.2, preferably with the admixture of a slag-forming material to the fly ash with a high content of SiO.sub.2.
- 5. A system for smelting fly ash to a leaching resistant slag while simultaneously being able to separates the content of heavy metals such as zinc and lead,
- characterized in that a plasma generator (1) with a supply device (4) for electrical energy and a supply device (5) for oxidizing gas is installed in connection with a first reactor (2),
- the first reactor (2) is conical in shape with increasing volume in the direction away from the plasma generator (1),
- the inlet to the first reactor (2) is equipped with a constriction (6), a supply device (7) for fly ash and optionally a slag-forming material, and a supply device (8) for a fuel,
- perpendicular to the first reactor (2) there is installed a second reactor (3) for collection of the smelted fly ash, the second reactor (3) has an outlet device (10) for gas and an outlet device (9) in the form of a slag lock for slag.
Priority Claims (1)
Number |
Date |
Country |
Kind |
951382 |
Apr 1995 |
NOX |
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Parent Case Info
This is a Continuation of: International Appln. No. PCT/NO96/00032 filed Feb 13, 1996 which designated the U.S.
US Referenced Citations (10)
Foreign Referenced Citations (2)
Number |
Date |
Country |
1529526 |
Oct 1978 |
GBX |
1538460 |
Jan 1979 |
GBX |
Continuations (1)
|
Number |
Date |
Country |
Parent |
PCTNO9600032 |
Feb 1996 |
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