WO2019000091A1 - STABILIZATION OF HAZARDOUS MATERIALS - Google Patents

STABILIZATION OF HAZARDOUS MATERIALS Download PDF

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Publication number
WO2019000091A1
WO2019000091A1 PCT/CA2018/050790 CA2018050790W WO2019000091A1 WO 2019000091 A1 WO2019000091 A1 WO 2019000091A1 CA 2018050790 W CA2018050790 W CA 2018050790W WO 2019000091 A1 WO2019000091 A1 WO 2019000091A1
Authority
WO
WIPO (PCT)
Prior art keywords
aluminum
arsenic
scorodite
gel
carbonate base
Prior art date
Application number
PCT/CA2018/050790
Other languages
English (en)
French (fr)
Inventor
George DEMOPOULOS
Original Assignee
The Royal Institution For The Advancement Of Learning/Mcgill University
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by The Royal Institution For The Advancement Of Learning/Mcgill University filed Critical The Royal Institution For The Advancement Of Learning/Mcgill University
Priority to CA3096126A priority Critical patent/CA3096126A1/en
Priority to PE2019002680A priority patent/PE20200766A1/es
Priority to MX2020000165A priority patent/MX2020000165A/es
Priority to CN201880049403.1A priority patent/CN110944724B/zh
Priority to AU2018292424A priority patent/AU2018292424B2/en
Priority to JP2019571443A priority patent/JP7265267B6/ja
Priority to EP18823982.6A priority patent/EP3645132A4/en
Publication of WO2019000091A1 publication Critical patent/WO2019000091A1/en

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Classifications

    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B09—DISPOSAL OF SOLID WASTE; RECLAMATION OF CONTAMINATED SOIL
    • B09B—DISPOSAL OF SOLID WASTE NOT OTHERWISE PROVIDED FOR
    • B09B3/00—Destroying solid waste or transforming solid waste into something useful or harmless
    • B09B3/20—Agglomeration, binding or encapsulation of solid waste
    • B09B3/25—Agglomeration, binding or encapsulation of solid waste using mineral binders or matrix
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B09—DISPOSAL OF SOLID WASTE; RECLAMATION OF CONTAMINATED SOIL
    • B09B—DISPOSAL OF SOLID WASTE NOT OTHERWISE PROVIDED FOR
    • B09B3/00—Destroying solid waste or transforming solid waste into something useful or harmless
    • B09B3/20—Agglomeration, binding or encapsulation of solid waste
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B09—DISPOSAL OF SOLID WASTE; RECLAMATION OF CONTAMINATED SOIL
    • B09C—RECLAMATION OF CONTAMINATED SOIL
    • B09C1/00—Reclamation of contaminated soil
    • B09C1/08—Reclamation of contaminated soil chemically

Definitions

  • This invention relates to stabilization / solidification of hazardous materials and, in particular, arsenical wastes through encapsulation with mineralized products of hydrolyzed aluminum gels.
  • Stabilization/solidification is an approach used for the fixation of toxic waste materials of various types and sources.
  • An example of such a process involves the mixing of a toxic waste with cement and/or other binder materials to produce a chemically and physically stable solid mass suitable for use in the landfill.
  • the most common technologies currently used for the stabilization/solidification of hazardous wastes are those based upon hydraulic cement and/or slaked lime and, less commonly, organic polymers, sulphur polymer cement, and other encapsulation materials.
  • a method for the stabilization of hazardous materials comprising:
  • carbonate base such as NaHC03 or Na 2 COs
  • aluminum gels and their mineralized products in stabilization of hazardous materials.
  • a composite comprising scorodite particles and a gel-derived solidified matrix comprising aluminum (oxy)hydroxide mineral phases.
  • a composite prepared by the method as defined herein.
  • FIG. 1 is a graph of the evolution profiles of pH and Eh with time during stability testing of scorodite-gel blends using either Na 2 S0 3 (top) or Na 2 S (bottom) to adjust Eh;
  • FIG. 2 depicts arsenic release from naked scorodite and scorodite encapsulated with aluminum gels derived from reference bases NaOH and Mg(OH) 2 , compared to a carbonate base
  • FIG. 3 depicts arsenic release from naked scorodite and scorodite encapsulated with aluminum gels derived from reference bases NaOH and Mg(OH) 2 , compared to a carbonate base
  • FIG. 4 is a graph showing the arsenic release from naked scorodite and scorodite encapsulated with Al-gels prepared from NaOH, Na2C03 and NaHC03 under anoxic (Na2S03) condition and pH ⁇ 9;
  • FIG. 5. represents the arsenic release from scorodite encapsulated with aluminum gels derived from Na 2 C0 3 and NaHC0 3 under anoxic condition chemically generated with Na 2 S;
  • FIG. 6 depicts XRD patterns of Na 2 C0 3 derived aluminum gels after 167 days stability testing under oxic and anoxic conditions;
  • FIG. 7 presents the profile of arsenic release from scorodite encapsulated with Al-gels prepared from Na 2 CC>3 or Mg(OH) 2 under oxic (with and without elemental sulfur present) or anoxic (Na 2 S) condition (with or without elemental sulfur present) in water of pH ⁇ 9 compared to release of arsenic under same conditions from naked scorodite; and
  • FIG. 8 is a schematic representation of scorodite particle encapsulated with gel-derived mineralized aluminum (oxy)hydroxides phases.
  • the inventors have discovered hydrolyzed aluminum gels derived from aluminum sulfate solutions by neutralization with carbonate bases to be highly effective in encapsulating hazardous materials like scorodite particles.
  • the said aluminum gels form a mineralized matrix protecting the scorodite particles from decomposition in alkaline or anoxic waters, hence minimizing release of arsenic.
  • the encapsulation process involves blending scorodite particles with gels prepared with carbonate bases from aluminum sulphate solution and storing the resultant composite that provides protection via the in situ formation of a mineralized aluminum (oxy)hydroxide matrix.
  • the carbonate base is comprising a carbonate anion (formula: CO3 2" ) or bicarbonate anion (formula: HCO 3 " - also referred to as hydrogen-carbonate ion in the IUPAC system).
  • Suitable carbonates include:
  • the carbonate base is NaHC0 3 or Na 2 C0 3 .
  • the molar ratio of Al:As is ranging from about 1.5 to 0.05; preferably less than about 1, or from about 1.0 to 0.1, or less than about 0.2, or more preferably from about 0.2 to 0.1, and most preferably about 0.1.
  • the concentration of Al(S0 4 ) l 5 in the aqueous medium for preparing the Al gel is ranging from about 0.5 to 3.0M (mol/L) of 1.0 to 3.0 mol/L; preferably, about 1.0 to 2.0, more preferably about 1.5 to 2.0, and most preferably about 2.0.
  • the carbonate bases can be used as powders or suspension/solution.
  • Na 2 C0 3 from about 0.5M to dry powder and preferably about 1.0M to 6M, more preferably about 2M to 4M and most preferably about 2.5 to 3M.
  • NaHC0 3 one can double these numbers, i.e. from about 1M to powder, or about 2M to 12M or about 4M to 8M or most preferably about 5 to 6M.
  • the amount will suitably vary depending on the concentration of Al sulfate solution.
  • the skilled person understands that it may not be desirable to use very dilute solutions of base or AI-SO 4 as this would lead to very liquid-like gel. On the other hand, it may not be desirable to use too concentrated a medium as this leads to immediate solidification (in the form of crushed ice) of the gel, and making more difficult its handling, such as its transportation to the storage site.
  • the temperature range for forming the gel or blending it with the hazardous material is from about 0 to 80°C, or preferably about 10 to 40°C, or more preferably about 15 to 30°C or about 20°C.
  • hazardous materials subjected to stabilization with hydrolyzed aluminum gels as defined herein is not especially limited. Examples include ferric arsenate/scorodite, but however may as well be other arsenical compounds, residues, precipitates or flue dusts such as arsenic sulfides, calcium arsenates or arsenites, mixed calcium arsenates- phosphates, ferrous arsenate, ferric arsenite, arsenic trioxide and so on. Further, the carbonate- derived aluminum gels could be used to provide additional protection to arsenical residues previously stabilized (partially) with conventional cement based methods.
  • the gels could be used for other types of hazardous materials, as is the case for example of antimony, mercury or selenium-containing wastes generated by smelting and other industrial operations.
  • "blending" may involve aging following mixing of the gel and the hazardous arsenical material or not before permanent disposal.
  • Non-limiting examples of aging time may be about one day or from 1 day to 30 days before permanent disposal (storing) of the blended material.
  • aqueous medium can be essentially water, optionally comprising conventional additional components present in the "hazardous materials" subjected to stabilization with hydrolyzed aluminum gels as defined herein.
  • the scorodite substrate material was synthesized by atmospheric precipitation via the use of a seed and supersaturation control method previously developed by the inventors.
  • 0.5 L As(V) - Fe(III) - H 2 S0 4 solutions containing 40 g/L arsenic(V) and iron(III) to arsenic molar ratio of one were placed in a reactor and heated to 95°C.
  • 5 g of hydrothermally produced scorodite were added to the reactor as seed.
  • precipitation started and was allowed to proceed for 24 hours, after which the slurry was filtered using a pressure filter with 0.22 ⁇ pore size membrane filter.
  • TCLP Toxicity Characterization Leachability Procedure-method developed by the Environmental Protection Agency-EPA- of the USA.
  • the freshly washed scorodite particles were subsequently used in aging with aluminum hydroxyl gels. All the reagents and chemicals used were of analytical grade.
  • Preferred gels were prepared using sodium bicarbonate (NaHCOs) and sodium carbonate (Na 2 CC>3) by partial neutralization of aluminum(III) sulfate solution.
  • magnesium hydroxide also as reference gel
  • sodium carbonate and sodium bicarbonate powders or previously dissolved or suspended in water (as reported in the specific examples given) were introduced to the prepared Al(S0 4 ) l 5 (typical concentration: 2 mol/L) solutions.
  • Mild stirring had to be applied during mixing as excessive force was found to be counter-productive, causing gel thinning.
  • the freshly prepared aluminum gels were used to stabilize scorodite particles.
  • This anoxic stability test was conducted at adjusted reducing potential (Eh) conditions ( 200 + 20 mV ) via the addition of sodium sulfite (0.15mol/L Na 2 SOs) solution. The pH of the solution was monitored and periodically adjusted to pH 9 ⁇ 0.2 with 0.5 mol/L Ca(OH)2 slurry. Refer to FIG. 1.
  • This anoxic stability test was conducted at adjusted reducing potential (E h ) of 50mV via addition of sodium sulfide solution (0.125M Na 2 S). The pH of the solution was monitored and periodically adjusted to pH 9 ⁇ 0.2 with 0.5 mol/L Ca(OH) 2 slurry. Refer to FIG. 1.
  • ICP-AES Inductively Coupled Plasma- Atomic Emission Spectrometer
  • an aluminum gel of acceptable quality for ageing tests is one that has a sufficiently high initial viscosity (at least 300 cP) to enable solid particles to be blended with the gel without subsequently settling. It is also preferable that the aluminum gel maintains a sufficiently high viscosity for enough time (e.g. 1 to 24 hours) for ease of transportation to storage site before it becomes solidified.
  • Tables 1-4 below summarizes some of the viscosity measurements. The measurements were made with a Brookfield LVDV-E Viscometer apparatus. [0037] Table 1 - NaOH pellets, Na 2 C0 3 , NaHC0 3 powders were introduced to a 2M Al(S0 4 )i.s solution.
  • NaHCC>3 and Na 2 CC>3 provided satisfactory initial viscosities under various reaction conditions except for very dilute (0.5M-Table 3) Al(S04)i.s solution.
  • tests showed gels made with NaOH suffered breakage with time, i.e. water/gel separation (Table 4).
  • scorodite encapsulated with the gel deriving from Na2C03 exhibited a negligible amount of arsenic release after 167 days, and was below the detection limit of the ICP-AES for arsenic (i.e. ⁇ 0.1 mg/L) at a final pH of -7.6. This is significantly lower than the permitted amount of released arsenic in leachate from industrial/mining waste ranging from 1.0 mg/L in certain countries like Japan to 5.0 mg/L in USA. Therefore, these gels display a superior performance for industrial usage. It was also observed that the arsenic released from the two types of hydroxide ions (i.e. NaOH and Mg(OH) 2 ) varied broadly and in an unexpected manner relative to each other.
  • FIG. 3 shows the arsenic release versus time for various aluminum gel/scorodite materials in comparison with scorodite substrate under anoxic environment (chemically generated under Na 2 SOs). It can be seen that the dissolution of scorodite (-137 mg/L in the case of naked mineral) was effectively suppressed with the aid of these aluminum gels encapsulations. The concentration of arsenic released from scorodite encapsulated with particular aluminum gels was reduced by at least one order of magnitude. The scorodite encapsulated with the sodium hydroxide -derived gels had a significantly higher arsenic release.
  • the arsenic released from the scorodite encapsulated with Al-gel derived from NaHC0 3 is no more than 0.1 mg/L and lower than that from Al-gel derived from Na 2 C0 3 .
  • the in-situ mineralization of the hydrolyzed aluminum gel into inert aluminum (oxy)hydroxide crystalline phases as schematically depicted in FIG. 8 provides a protective layer to the scorodite particles, thus preventing their dissolution/decomposition.
  • the mineralized aluminum (oxy)hydroxide matrix is immune to pH and redox potential swings compared to those caused by the addition of chemical reducing agents, hence greatly enhancing the stabilization of the toxic material.

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  • Engineering & Computer Science (AREA)
  • Environmental & Geological Engineering (AREA)
  • Processing Of Solid Wastes (AREA)
  • Removal Of Specific Substances (AREA)
  • Solid-Sorbent Or Filter-Aiding Compositions (AREA)
  • Compounds Of Alkaline-Earth Elements, Aluminum Or Rare-Earth Metals (AREA)
PCT/CA2018/050790 2017-06-29 2018-06-27 STABILIZATION OF HAZARDOUS MATERIALS WO2019000091A1 (en)

Priority Applications (7)

Application Number Priority Date Filing Date Title
CA3096126A CA3096126A1 (en) 2017-06-29 2018-06-27 Stabilization of hazardous materials
PE2019002680A PE20200766A1 (es) 2017-06-29 2018-06-27 Estabilizacion de materiales peligrosos
MX2020000165A MX2020000165A (es) 2017-06-29 2018-06-27 Estabilizacion de materiales peligrosos.
CN201880049403.1A CN110944724B (zh) 2017-06-29 2018-06-27 危险材料的稳定化
AU2018292424A AU2018292424B2 (en) 2017-06-29 2018-06-27 Stabilization of hazardous materials
JP2019571443A JP7265267B6 (ja) 2017-06-29 2018-06-27 有害物質の安定化
EP18823982.6A EP3645132A4 (en) 2017-06-29 2018-06-27 STABILIZATION OF DANGEROUS MATERIALS

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
US201762526511P 2017-06-29 2017-06-29
US62/526,511 2017-06-29

Publications (1)

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WO2019000091A1 true WO2019000091A1 (en) 2019-01-03

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EP (1) EP3645132A4 (zh)
JP (1) JP7265267B6 (zh)
CN (1) CN110944724B (zh)
AU (1) AU2018292424B2 (zh)
CA (1) CA3096126A1 (zh)
CL (1) CL2019003807A1 (zh)
MX (1) MX2020000165A (zh)
PE (1) PE20200766A1 (zh)
WO (1) WO2019000091A1 (zh)

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CN111069228A (zh) * 2019-11-22 2020-04-28 昆明理工大学 一种铜渣凝胶包裹稳定化臭葱石的方法
CN112718793A (zh) * 2020-12-15 2021-04-30 紫金矿业集团股份有限公司 一种含亚砷酸盐的含砷物料直接玻璃化固砷方法

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JP2012240017A (ja) 2011-05-23 2012-12-10 Nittetsu Kankyo Engineering Kk 有害物質の処理材及び有害物質の処理方法
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Publication number Priority date Publication date Assignee Title
CN111069228A (zh) * 2019-11-22 2020-04-28 昆明理工大学 一种铜渣凝胶包裹稳定化臭葱石的方法
CN112718793A (zh) * 2020-12-15 2021-04-30 紫金矿业集团股份有限公司 一种含亚砷酸盐的含砷物料直接玻璃化固砷方法

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Publication number Publication date
JP7265267B6 (ja) 2023-05-19
JP2020525121A (ja) 2020-08-27
EP3645132A1 (en) 2020-05-06
CL2019003807A1 (es) 2020-08-14
PE20200766A1 (es) 2020-07-30
CN110944724A (zh) 2020-03-31
MX2020000165A (es) 2020-07-22
JP7265267B2 (ja) 2023-04-26
EP3645132A4 (en) 2021-03-03
AU2018292424B2 (en) 2023-09-28
CN110944724B (zh) 2022-08-26
AU2018292424A1 (en) 2020-02-13
CA3096126A1 (en) 2019-01-03

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