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US5296293A Expired / Lapsed US ⏱️ 0.0 years remaining

Particulate material suitable for the removal of heavy metals

Assignee: EIDP Inc
•
Filing: 1991-12-23
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Granted: 1994-03-22
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Expires: 2011-12-23
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Abstract

Abstract A particulate material suitable for the removal of heavy metals from an aqueous effluent comprises a finely ground solid encapsulated in a microporous shell of a polyvinyl chloride. The solid may be peat. The shell comprises a sufficient amount of polyvinyl chloride to utilize the adsorptive qualities of the peat while imparting structural integrity thereto. A process for making the particulate material comprises the steps of dissolving a polyvinyl chloride in an organic solvent therefor to produce a polymer solution, combining the polymer solution with a solid to produce a homogenous dispersion, forming droplets from the dispersion and contacting the droplets with water to precipitate out a particulate material comprising a finely ground solid encapsulated in a microporous shell of the polyvinyl chloride. The material may be modified after the solid is encapsulated, or the solid of the material may be modified before it is encapsulated. The material or the peat is modified with a calcium salt, such as calcium carbonate, or a sodium salt, such as sodium hydroxide. Raw peat which is modified with a calcium salt, preferably calcium carbonate, is also suitable for the removal of heavy metals from an aqueous effluent.

Inventors

  • 👤 Wolfram Jobst

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-11-08 20:02
CPC Classifications
B; B01; B01J; B01J20/00; B01J20/22; B01J20/24; B01J20/26; B01J20/261; B01J20/28; B01J20/28002; B01J20/28004; B01J20/28054; B01J20/28078; B01J20/30; B01J20/3021; B01J20/3092; B01J20/32; B01J20/3202; B01J20/3206; B01J20/3231; B01J20/3242; B01J20/3268; B01J20/327; B01J20/3291; B01J20/3293; C; C02; C02F; C02F1/00; C02F1/28; C02F1/288; B01J2220/00; B01J2220/40; B01J2220/48; B01J2220/4812; B01J2220/485; B01J2220/50; B01J2220/58; Y; Y10; Y10S; Y10S210/00; Y10S210/902; Y10S210/911; Y10S210/912; Y10T; Y10T428/00; Y10T428/29; Y10T428/2982; Y10T428/2991; Y10T428/2998

Claims Analysis

Total Claims: 5
Claim 1
Independent Claim 46 words
A particulate material suitable for the removal of heavy metals from an aqueous effluent, comprising: peat finely ground to an average size below about 30 mesh encapsulated in a microporous shell of a polyvinyl chloride, wherein the weight percentage of the peat is less than 82%.
Claim 2
Dependent Claim 46 words
A particulate material suitable for the removal of heavy metals from an aqueous effluent, comprising: peat finely ground to an average size below about 30 mesh encapsulated in a microporous shell of a polyvinyl chloride, wherein the weight percentage of the peat is less than 82%.
Claim 3
Dependent Claim 30 words
The particulate material of claim 1, wherein the shell comprises a sufficient amount of the polyvinyl chloride to utilize the adsorptive qualities of the peat while imparting structural integrity thereto.
Claim 4
Dependent Claim 23 words
The particulate material of claim 2, wherein the weight percentage of the polyvinyl chloride is in the range of about 18% to 50%.
Claim 5
Dependent Claim 23 words
The particulate material of claim 3, wherein the weight percentage of the polyvinyl chloride is in the range of about 20% to 30%.

References Cited (Backward Citations)

JPS5621777A Cited
JPS5631317A Cited
GB2063228A Cited
JPS5767515A Cited
EP0119925A2 Cited
US4829045A Cited
JPS6250200A Cited
WO1991005859A1 Cited

USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 1997-03-21 1997-09-20 1998-03-22 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 2001-03-21 2001-09-20 2002-03-22 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 2005-03-21 2005-09-20 2006-03-22 $7700.00 Window Closed / Lapsed

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