US4404105A
Expired / Lapsed
US
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Process for treatment of waste
Assignee: Internationale de Publicite et D'agences Commerciales Ste
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Filing: 1981-10-02
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Granted: 1983-09-13
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Expires: 2001-10-02
Abstract
Abstract Process for the irreversible treatment of toxic waste by means of a silicate, in the presence of water, in such a way as to form a solid aggregate includes treatment of the silicate in an acid medium, for the purpose of obtaining silicic acid of low molecular weight; mixing the silicic acid with the waste to be treated, in the presence of water and controlling the pH between 0 and 4 in a sufficiently acid medium to cause the waste to undergo at least partial solution; precipitation of a gel of high molecular weight from the resultant aqueous mixture; addition thereto of a mixture which reacts with the gel of high molecular weight to form a silicate, possibly in the presence of a cementation agent, in such a way as to produce a sludge, and the hardening of the sludge into a solid aggregate which can not be changed physically so as to release again the harmful or toxic waste into the environment.
Inventors
- 👤 Serge H. Rysman de Lockerente
- 👤 Norbert Van de Voorde
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-06 20:11
CPC Classifications
C; C04; C04B; C04B18/00; C04B18/04; C04B18/0463; C04B18/02; C04B18/021; C04B28/00; C04B28/24; G; G21; G21F; G21F9/00; G21F9/04; G21F9/06; G21F9/16; G21F9/162; G21F9/165; G21F9/28; G21F9/30; G21F9/301; G21F9/302; G21F9/304; Y; Y02; Y02W; Y02W30/00; Y02W30/50; Y02W30/91; Y10; Y10S; Y10S210/00; Y10S210/902; Y10S210/911; Y10S210/912; Y10S210/913; Y10S210/914
Claims Analysis
Total Claims: 37
Claim 1
Independent Claim
237 words
A process for the formation of a chemically stable solid aggregate of wastes containing at least one heavy metal or heavy metal compound which is at least partially water soluble under acid conditions comprising the sequential steps of: (a) forming a low-polymerization-silicic-acid of molecular weight not exceeding 50,000 by reacting (i) a silicate selected from at least one of the group consisting of alkaline earth metal silicates, aluminum silicates, and aluminosilicates, (ii) water, and (iii) acid sufficient to provide the reaction mixture with a pH between about 0.5 and about 3; (b) mixing (i) the wastes containing heavy metals or heavy metal compounds, and (ii) the low-polymerization-silicic-acid, with (iii) sufficient water and acid, to adjust the mixture to one having at least 70% dissolved solids and a pH of less than 4; (c) synthesizing a higher-polymerization-silicic-acid/hydrated-heavy-metal coprecipitate gel, by reacting (i) the low-polymerization-silicic-acid, and (ii) the cations of the heavy metal in the wastes, (iii) in the presence of a base catalyst selected from at least one of the group consisting of sodium hydroxide, potassium hydroxide, calcium hydroxide, their carbonates or hydrocarbonates, in an amount sufficient to increase the pH of the mixture to progressively to at least 7; and (d) hardening the coprecipitate gel into a chemically stable solid aggregate; wherein the total amount of water in above steps (a) through (d) is at least 15 percent by weight based upon the total weight of solids.
Claim 2
Dependent Claim
237 words
A process for the formation of a chemically stable solid aggregate of wastes containing at least one heavy metal or heavy metal compound which is at least partially water soluble under acid conditions comprising the sequential steps of: (a) forming a low-polymerization-silicic-acid of molecular weight not exceeding 50,000 by reacting (i) a silicate selected from at least one of the group consisting of alkaline earth metal silicates, aluminum silicates, and aluminosilicates, (ii) water, and (iii) acid sufficient to provide the reaction mixture with a pH between about 0.5 and about 3; (b) mixing (i) the wastes containing heavy metals or heavy metal compounds, and (ii) the low-polymerization-silicic-acid, with (iii) sufficient water and acid, to adjust the mixture to one having at least 70% dissolved solids and a pH of less than 4; (c) synthesizing a higher-polymerization-silicic-acid/hydrated-heavy-metal coprecipitate gel, by reacting (i) the low-polymerization-silicic-acid, and (ii) the cations of the heavy metal in the wastes, (iii) in the presence of a base catalyst selected from at least one of the group consisting of sodium hydroxide, potassium hydroxide, calcium hydroxide, their carbonates or hydrocarbonates, in an amount sufficient to increase the pH of the mixture to progressively to at least 7; and (d) hardening the coprecipitate gel into a chemically stable solid aggregate; wherein the total amount of water in above steps (a) through (d) is at least 15 percent by weight based upon the total weight of solids.
Claim 3
Dependent Claim
18 words
The process of claim 1 wherein the pH of step (a) is between about 1 and about 3.
Claim 4
Dependent Claim
101 words
The process of claim 2 wherein the heavy metal or heavy metal compound contained in the wastes to be aggregated is at least one of the group consisting of aluminum, antimony, silver, arsenic, barium, beryllium, bismuth, cadmium, calcium, cerium, cesium, chromium, cobalt, copper, tin, iron, lithium, magnesium, manganese, mercury, nickel, lead, plutonium, radium, strontium, thorium, uranium, vanadium, and zinc, and a compound of any of these metals, including an oxide, hydroxide or salt, consisting of at least one anion of the anions of sulphate, sulphite, nitrate, nitrite, phosphate, phosphite, fluoride, chloride, bromide, nitride, cyanide, sulphide, cyanate, thiocyanate, thiosulphate, ferricyanide or ferrocyanide.
Claim 5
Dependent Claim
19 words
The process of claim 3 wherein the wastes also contain at least one organic compound having a polar function.
Claim 6
Dependent Claim
39 words
The process of claim 4 wherein the organic compound is a carboxylic acid, protein, carbohydrate, fat, therapeutic agent, coloring agent, pesticide, detergent, mineral oil, hydrocarbon, phenol, latex waste, aminated base, stearate, oleate, or mixture of any of the above.
Claim 7
Dependent Claim
40 words
The process of claim 4 wherein the organic wastes are present in a concentration of from about 5% to about 20% by weight of the weight of the wastes and are in the form of an aqueous solution or suspension.
Claim 8
Dependent Claim
14 words
The process of claim 6 wherein the organic wastes are added before step (c).
Claim 9
Dependent Claim
14 words
The process of claim 6 wherein the organic wastes are added after step (c).
Claim 10
Dependent Claim
21 words
The process of claim 2 wherein the wastes contain solids which are dissolved before mixing with the low-polymerization-silicic-acid in step (b).
Claim 11
Dependent Claim
105 words
The process of claim 2 wherein the wastes are selected from at least one of the group consisting of: (i) steel industry-pickling liquids, neutralization sludges, solids and sludges produced by a material collector, soluble salts produced by the regeneration of acids, (ii) mining-liquids produced by a neutralization station, (iii) power station produced boiler ash, (iv) surface treatment works-metal salt liquids, acid and base liquids, purification of waste water liquids and sludges, liquids produced by recuperation of an ion exchanger, (v) chemical factory-acid and base liquids, metal salt liquids, (vi) non-ferrous metal-pickling liquids, soluble salts produced by recuperation of acids, and solids which are manufacturing waste.
Claim 12
Dependent Claim
24 words
The process of claim 10 wherein the wastes are acidic liquids having at least 70% dissolved solids and a pH of 4 or less.
Claim 13
Dependent Claim
16 words
The process of claim 11 wherein no further water or acid is added in step (a).
Claim 14
Dependent Claim
21 words
The process of claim 2 wherein the silicate of step (a) is a solid aluminosilicate which is a blast furnace slag.
Claim 15
Dependent Claim
29 words
The process of claim 13 wherein the slag is granulated and step (d) is conducted by adding lime or sodium hydroxide to the coprecipitate gel to harden the same.
Claim 16
Dependent Claim
23 words
The process of claim 2 wherein the acid of step (a) is sulphuric, hydrochloric, nitric, or a mixture of at least two thereof.
Claim 17
Dependent Claim
20 words
The process of claim 2 wherein the mixture of step (b) has at least about 85% to 95% dissolved solids.
Claim 18
Dependent Claim
14 words
The process of claim 16 wherein substantially all of the wastes solids are dissolved.
Claim 19
Dependent Claim
28 words
The process of claim 2 wherein the mixing of step (b) is conducted within a time ranging from immediately the low-polymerization-silicic-acid is formed up to about three days.
Claim 20
Dependent Claim
19 words
The process of claim 18 wherein the mixing of step (b) is conducted substantially immediately the low-polymerization-silicic-acid is formed.
Claim 21
Dependent Claim
23 words
The process of claim 2 wherein the wastes solids are dissolved in advance, in a separate phase, prior to mixing with the low-polymerization-silicic-acid.
Claim 22
Dependent Claim
37 words
The process of claim 2 wherein the pH of the wastes is from low acidity to alkaline and a sufficient quantity of acid is added in step (b) to reduce the pH to about 1 or less.
Claim 23
Dependent Claim
30 words
The process of claim 3 wherein the wastes contain at least copper and the pH of step (b) is about 4 or less, in order to render the copper soluble.
Claim 24
Dependent Claim
30 words
The process of claim 3 wherein the wastes contain at least iron and the pH of step (b) is about 1 or less, in order to render the iron soluble.
Claim 25
Dependent Claim
20 words
The process of claim 2 wherein the pH of step (c) is increased up to from about 7 to 8.
Claim 26
Dependent Claim
13 words
The process of claim 2 wherein the base catalyst is a basic slag.
Claim 27
Dependent Claim
14 words
The process of claim 2 wherein the base catalyst is lime or sodium hydroxide.
Claim 28
Dependent Claim
24 words
The process of claim 2 wherein step (d) is conducted by permitting the coprecipitate gel to harden in the absence of a cementation additive.
Claim 29
Dependent Claim
14 words
The process of claim 27 wherein the coprecipitate gel is heated to accelerate hardening.
Claim 30
Dependent Claim
36 words
The process of claim 2 wherein step (d) is conducted by adding a cementation agent to the coprecipitate gel accompanied by mixing, in an amount sufficient to form a sludge, and permitting the sludge to harden.
Claim 31
Dependent Claim
40 words
The process of claim 29 wherein the cementation agent is selected from at least one of the group consisting of Portland cements with or without secondary constituents, mixed metallurgical cements, clinker slag cements, supersulphated cements, aluminous cements or sodium silicate.
Claim 32
Dependent Claim
25 words
The process of claim 30 wherein the amount of cementation agent added is from about 5% to about 50% by weight of the total mixture.
Claim 33
Dependent Claim
36 words
The process of claim 29 wherein step (d) is conducted by adding a hardening aid to the coprecipitate gel selected from at least one of the group consisting of slaked lime, hydrated lime, and caustic soda.
Claim 34
Dependent Claim
28 words
The process of claim 32 wherein the gel or step (c) is first separated from the aqueous solution containing it and the resulting practically pure water is recycled.
Claim 35
Dependent Claim
16 words
The process of claim 33 wherein the water is recycled into step (b) of the process.
Claim 36
Dependent Claim
40 words
The process of claim 33 wherein the water is recycled into step (d) of the process by using it to form a liquid paste with at least one of the group consisting of the cementation agent or the hardening aid.
Claim 37
Dependent Claim
36 words
The process of claim 2 wherein step (d) is conducted by adding a hardening aid to the coprecipitate gel selected from at least one of the group consisting of slaked lime, hydrated lime, and caustic soda.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1986-09-12 | 1987-03-14 | 1987-09-13 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1990-09-12 | 1991-03-14 | 1991-09-13 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1994-09-12 | 1995-03-14 | 1995-09-13 | $7700.00 | Window Closed / Lapsed |