Patent US3845323A successfully refreshed from Google Patents.
Patent US3958150A successfully refreshed from Google Patents.
US4069033A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Extraction of fertilizer salts and organic substances of high nutritive value from industrial waste waters
Assignee: Reggiane Cranes and Plants SpA
•
Filing: 1975-09-19
•
Granted: 1978-01-17
•
Expires: 1995-09-19
Abstract
Abstract A process for obtaining fertilizer salts and organic substance concentrates of high nutritive value from industrial waste waters, in particular of waste waters of the agricultural, food processing and food preserving industries, with a high content of Totally Dissolved Solids (T.D.S.), includes the following operating phases: Automatic diversion of the high T.D.S. content waste waters from those of low T.D.S. content by means of a conductivity or density measuring instrument. Mixing of the high T.D.S. content waste waters with strong acids or bases, according to the composition of the waste waters, so as to form stable salts. Filtration of the so-formed solution for the purpose of eliminating the insoluble substances and precipitates. Concentration of the solution by means of evaporation. Crystallization of the concentrated solution. Separation by means of centrifugation of the fertilizer salts from the mother liquors containing organic substances of high nutritive value.
Inventors
- 👤 Paolo Baldassari
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 13:41
CPC Classifications
C; C05; C05F; C05F5/00; C05F5/006; A; A23; A23K; A23K10/00; A23K10/30; A23K10/37; C02; C02F; C02F9/00; C05F5/008; C05F7/00; Y; Y02; Y02A; Y02A40/00; Y02A40/10; Y02A40/20; Y02P; Y02P60/00; Y02P60/80; Y02P60/87
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
156 words
A process for the extraction of fertilizer salts, on the one hand, and concentrates of organic substances having a high nutritive value, on the other hand, from industrial waste waters, comprising the following successive steps: monitoring the T.D.S. cntent of the waste water; automatically diverting waste waters of high T.D.S. content to the following additional steps from waste water of low T.D.S. which does not undergo the following additional steps; mixing the waste waters of high T.D.S. content with strong acids or bases, according to the composition of the waste water, in a quantity sufficient to form stable salts of low solubility; filtering the formed mixture to eliminate insoluble substances or precipitates; concentrating the filtrate by evaporation until the less soluble salts are saturated; crystallizing the concentrated filtrate at least once; separating the crystallized mineral salts, for use as fertilizer salts, from the mother liquor which is the concentrate of organic substances having high nutritive value.
Claim 2
Dependent Claim
156 words
A process for the extraction of fertilizer salts, on the one hand, and concentrates of organic substances having a high nutritive value, on the other hand, from industrial waste waters, comprising the following successive steps: monitoring the T.D.S. cntent of the waste water; automatically diverting waste waters of high T.D.S. content to the following additional steps from waste water of low T.D.S. which does not undergo the following additional steps; mixing the waste waters of high T.D.S. content with strong acids or bases, according to the composition of the waste water, in a quantity sufficient to form stable salts of low solubility; filtering the formed mixture to eliminate insoluble substances or precipitates; concentrating the filtrate by evaporation until the less soluble salts are saturated; crystallizing the concentrated filtrate at least once; separating the crystallized mineral salts, for use as fertilizer salts, from the mother liquor which is the concentrate of organic substances having high nutritive value.
Claim 3
Dependent Claim
62 words
An extraction process according to claim 1, wherein said monitoring and diverting steps are carried out by means of a conductivity meter or a densimiter, depending on the chemical and physical characteristics of the wastes, the said instrument controlling automatically a flow control valve capable of directing and conveying only the high T.D.S. content waste waters to the following successive operational steps.
Claim 4
Dependent Claim
35 words
An extraction process according to claim 1, wherein the acids used in said mixing step comprise sulphuric acid, phosphoric acid or nitric acid, either as reagents or as waste solutions obtained from preceding working steps.
Claim 5
Dependent Claim
34 words
An extraction process according to claim 1, wherein the bases used in said mixing step comprise potassium hydroxide or ammoniac potassium, either as pure reagents or in waste solutions obtained from preceding working steps.
Claim 6
Dependent Claim
34 words
An extraction process according to claim 1, further including the step of filtering for a second time said filtrate after said concentrating step, to eliminate possible insoluble substances formed during the preceding concentrating step.
Claim 7
Dependent Claim
24 words
An extraction process in accordance with claim 1, wherein the waste waters being treated are waste waters of the agricultural, food-processing or food-preservation industries.
Claim 8
Dependent Claim
39 words
An extraction process in accordance with claim 1, further including the steps of using the mineral salts obtained from said separating step as fertilizer salts and using the mother liquor obtained from said separating step as additive for fodder.
Claim 9
Dependent Claim
44 words
An extraction process in accordance with claim 1, wherein said mixing step comprises mixing a sufficient amount of a sufficiently strong acid to shift the ionic equilibrium of the solution and form less soluble salts with the cations which are present in the solution.
References Cited (Backward Citations)
US3171804A
Cited
US3236766A
Cited
US3650686A
Cited
US3605775A
Cited
US3725263A
Cited
US3936375A
Cited
US3865568A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1981-01-16 | 1981-07-18 | 1982-01-17 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1985-01-16 | 1985-07-18 | 1986-01-17 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1989-01-16 | 1989-07-18 | 1990-01-17 | $7700.00 | Window Closed / Lapsed |