Claims
- 1. An immobilization agent for toxic heavy metals wherein said immobilization agent is mixed in sufficient amounts with said heavy metals to solidify said mixture, said immobilization agent comprising 100 parts by weight of cement and 40 to 140 parts by weight of the mixture of ferrous chloride, iron oxalate and amorphous aluminum silicate and in which the ratio of ferrous chloride: iron oxalate: amorphous aluminum silicate is 5 to 30% by weight: 5 to 50% by weight: 20 to 90% by weight.
- 2. An immobilization agent according to claim 1, in which said ferrous chloride, iron oxalate and amorphous aluminum silicate are contained as a granulate prepared by a procedure in which ferrous chloride and iron oxalate are mixed together with amorphous aluminum silicate and granulated and heated in an inert gas stream.
- 3. An immobilization agent according to claim 1 or 2, which contains at least one selected from the group consisting of 0.05 to 0.35% by weight of potassium chloride, 0.03 to 0.20% by weight of magnesium chloride, 0.03 to 0.20% by weight of sodium chloride, 0.0002 to 0.01% by weight of cobalt chloride, 0.05 to 0.5% by weight of aluminum sulfate, 0.0002 to 0.01% by weight of citric acid, 0.03 to 0.25% by weight of calcium chloride and 0.001 to 0.02% by weight of sodium sulfate in addition to the compound mentioned above.
- 4. A process for the immobilization of toxic heavy metals contained in industrial waste comprising the steps of: (a) mixing 100 parts by weight of cement and 40 to 140 parts by weight of the mixture consisting of 5 to 30% by weight of ferrous chloride, 5 to 50% by weight of iron oxalate and 20 to 90% by weight of amorphous aluminum silicate to prepare a granulate; (b) adding the granulate to water and the industrial waste to form a mixture; and (c) milling, curing and solidifying the mixture.
- 5. A process according to claim 4, in which said granulate of ferrous chloride, iron oxalate and amorphous aluminum silicate is prepared by first mixing ferrous chloride and iron oxalate together with amorphous aluminum silicate and subsequently heating said mixture in an inert gas stream.
- 6. A process according to claim 5, in which said heating step is conducted at a temperature of about 50.degree. to 600.degree. C. under nitrogen or argon gas stream while agitated for about 5 to 30 minutes.
- 7. A process according to claims 4, 5 or 6, which contains at least one selected from the group consisting of 0.05 to 0.35% by weight of potassium chloride, 0.03 to 0.20% by weight of magnesium chloride, 0.03 to 0.20% by weight of sodium chloride, 0.0002 to 0.01% by weight of cobalt chloride, 0.05 to 0.5% by weight of aluminum sulfate, 0.0002 to 0.01% by weight of citric acid, 0.03 to 0.25% by weight of calcium chloride and 0.001 to 0.02% by weight of sodium sulfate is added to said granulate.
Priority Claims (1)
Number |
Date |
Country |
Kind |
3-305303 |
Oct 1991 |
JPX |
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Parent Case Info
This is a continuation of co-pending application Ser. No. 07/929,794, filed on Aug. 13, 1992, now abandoned.
US Referenced Citations (4)
Foreign Referenced Citations (3)
Number |
Date |
Country |
133578 |
Nov 1978 |
JPX |
44084 |
Apr 1981 |
JPX |
44085 |
Apr 1981 |
JPX |
Continuations (1)
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Number |
Date |
Country |
Parent |
929794 |
Aug 1992 |
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