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WO1997036829A1 - Procede pour traiter des eaux usees acides - Google Patents

Procede pour traiter des eaux usees acides Download PDF

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Publication number
WO1997036829A1
WO1997036829A1 PCT/AU1997/000179 AU9700179W WO9736829A1 WO 1997036829 A1 WO1997036829 A1 WO 1997036829A1 AU 9700179 W AU9700179 W AU 9700179W WO 9736829 A1 WO9736829 A1 WO 9736829A1
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WO
WIPO (PCT)
Prior art keywords
precipitate
ions
acid
green
vessel
Prior art date
Legal status (The legal status 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 status listed.)
Ceased
Application number
PCT/AU1997/000179
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English (en)
Inventor
Reginald Morton Taylor
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Geo2 Ltd
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Geo2 Ltd
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 Geo2 Ltd filed Critical Geo2 Ltd
Priority to US09/155,490 priority Critical patent/US6139753A/en
Priority to AU20184/97A priority patent/AU704342B2/en
Publication of WO1997036829A1 publication Critical patent/WO1997036829A1/fr
Anticipated expiration legal-status Critical
Ceased legal-status Critical Current

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Classifications

    • C—CHEMISTRY; METALLURGY
    • C02—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
    • C02F—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
    • C02F1/00—Treatment of water, waste water, or sewage
    • C02F1/58—Treatment of water, waste water, or sewage by removing specified dissolved compounds
    • C02F1/62—Heavy metal compounds

Definitions

  • This invention relates to precipitation processes for the remediation of acidic waste and drainage waters comprising metal and/or metalloid ions such as ions selected from (but not restricted to) the group consisting of copper, zinc, lead, mercury, cadmium, iron, arsenic, barium, selenium, silver, chromium, aluminium, manganese, nickel, cobalt, uranium and antimony.
  • metal and/or metalloid ions such as ions selected from (but not restricted to) the group consisting of copper, zinc, lead, mercury, cadmium, iron, arsenic, barium, selenium, silver, chromium, aluminium, manganese, nickel, cobalt, uranium and antimony.
  • the invention relates to the remediation of acidic waste water comprising iron ions and sulfate ions, as well as other undesirable metal or metalloid species.
  • acidic waste water comprising iron ions and sulfate ions, as well as other undesirable metal or metalloid species.
  • Such waters are frequently formed as a result of the oxidation and leaching of sulfide minerals during and after mining operations, and are referred to as acid mine drainage.
  • In-situ mitigation is a method whereby limestone placements are put down to collect surface run-off and funnel it into waste rock dumps.
  • Such a method is described in SITE 94, p. 374, presented by the University of South Carolina.
  • SITE 94 refers to the US EPA Superfund innovative Technology Evaluation Program, Technology Profiles, Seventh Edition 1994. This document is issued by the Risk Reduction Engineering Laboratory Office of Research and Development, US EPA Cincinnati, Ohio, 45268, USA.
  • Acidic material is capped with an impermeable layer to divert water from the acid cores. This method relies on the existence of sufficient rainfall to produce seepage or drainage that continually contacts the limestone. The method has limited efficiency for remediation (as judged by the acidity of treated versus untreated areas) and is weather dependent.
  • Wet-lands based treatment has also been considered. This method uses a man- made wet-land ecosystem to remove heavy metals and is described in SITE 94, p. 164 (Colorado Department of Public Health and Environment). This method is not able to recover useful metals from the acid mine drainage and removal efficiencies are generally less than for chemical precipitation processes.
  • SITE 94 at p. 304 describes a method involving precipitation plus adsorption in which the pH of the waste stream is adjusted to 9-10 (under standard atmospheric conditions) followed by pumping/drainage through a column containing adsorbent ferrihydrite applied to the surface of an inert substrate such as sand.
  • This method has limited efficiency for the removal of sulfate anions and generates relatively dilute strip liquor.
  • the adjustment under oxidising atmospheric conditions to pH up to 9-10 will involve the precipitation of large quantities of amorphous or poorly crystalline ferrihydrite having particle size and surface characteristics which lead to high sludge volumes and consequently to facile blocking of separation columns.
  • the limestone neutralisation/aeration step removes Fe, Al, Cu, and some sulfate.
  • the Fe is removed as Fe(lll) hydroxide (ferrihydrite), and whilst this precipitate has better settling characteristics than when lime is used as a precipitating agent, significant processing difficulties related to long settling times and filter clogging would be anticipated to occur.
  • the lime neutralisation step removes cadmium, zinc and manganese from the aqueous phase, and a pH of 10 or greater is necessary to reduce manganese to below 3ppm.
  • the sludge formed has a large volume and is slimy and difficult to settle and filter. It is unstable with respect to discharge back into the Pit and must be disposed in a controlled area or extracted for metal values.
  • Huang et al. noted a number of problems with the neutralisation process including the inability to remove aluminium and manganese at the same time and the instability of the sludge with respect to re-dissolution in the Pit.
  • the formula for the Jarosite family of compounds is AB 3 (XO 4 ) 2 (OH) n .mH 2 O
  • A represents monovalent or divalent metal species (commonly Pb, possibly Ag, NH 4 , H 3 O, Na, K) and B represents a trivalent or tetravalent metal species (e.g. Fe(lll), Al(lll), Sn(IV)).
  • X represents a member of the family consisting of sulphur, phosphorus, silicon, arsenic.
  • the most common Jarosites are based on trivalent iron and have a formula of M[Fe(OH) 2 ] 3 (SO 4 ) 2 where M is the species H 3 O, Li, Na, K, NH 4 , Ag and 0.5 Pb.
  • the Jarosite remediation process is not suitable for the remediation of acid mine drainage because
  • a method of treatment of acid waste waters containing heavy metals including ferrous and ferric ion comprising increasing the pH of the acid waste to at least 7.5 by additions of an alkaline reagent under conditions such that ferrous ions are stable with respect to oxidation to ferric ions (herein referred to as non-oxidising conditions) to form a precipitate and collecting the precipitate.
  • the method will preferably involve increasing the pH from its starting value to at least 7.5 under the non-oxidising conditions and subsequently increasing the pH to at least 8.
  • the pH range 6.0 to 7.5 is the most critical to providing formation of a precipitate which may be easily filtered and which binds undesirable species present in the acid mine drainage.
  • Alkaline reagents which may be added to the acid mine drainage can be chosen from the group consisting of lime, limestone, sodium carbonate, sodium hydroxide, potassium hydroxide, calcined dolomite, magnesia, ammonium hydroxide. These reagents may be insoluble or in finely suspended form, or in the form of finely divided powder.
  • Conditions in which ferrous ions in the initial waste stream are stable against oxidation to ferric ions may be achieved either by carrying out the precipitation reaction under a non-oxidising atmosphere (e.g. nitrogen, argon, natural gas) or by carrying out the precipitation reaction in a filled, closed reactor vessel such as a pipe.
  • a non-oxidising atmosphere e.g. nitrogen, argon, natural gas
  • a filled, closed reactor vessel such as a pipe.
  • the colour of the precipitate foimed in the pH range of pH 6.0 - 7.5 is green, and said precipitate is highly susceptible to oxidation becoming honey-brown in colour when exposed to oxygen or other oxidizing atmospheres.
  • the green precipitate formed in the regime pH 6.0 -7.5 has been found to belong structurally to the pyroaurite class of compounds, which according to Hansen et al. consist of alternating positively charged trioctahedral metal hydroxide layers and negatively charged interlayers of anions such as chloride, sulphate, carbonate (see Evaluation of Free Energy of Formation of Fe(ll)/Fe(lll) Hydroxide- Sulfate (green rust) and its Reduction of Nitrate, H.B. Hansen et al. Geochemica Cosmochemica Acta 1994 Vol. 58 No.12 pp2599-2602).
  • the pyroaurite compounds have the general composition
  • a common pyroaurite type compound which may be formed from acid mine drainage using the process of this invention is Green Rust comprising Fe(ll) - Fe(lll) hydroxides with interlayer sulfate ions or other anions.
  • Green Rust may be detected by means of X ray diffraction and by means of Mossbauer spectroscopy (see references below). The latter method is useful where the X ray diffraction lines are masked for example by more highly crystalline materials such as gypsum.
  • Green Rust and other pyroaurite-like compounds are their ability, if not seriously degraded, to transform by thermal decomposition to a crystalline spinel or ferrite structure.
  • At least 30% by weight of the precipitate formed in the pH regime 6.0 - 7.5 will comprise pyroaurite-like compounds.
  • Acid mine drainage will in general comprise divalent and trivalent metal cations and we have found that the ratio of divalent cations to trivalent cations effects the efficiency with which the desired precipitate is formed.
  • the ratio obtained by taking the sum of the mole quantities of non-calcium divalent species per litre and dividing by the sum of the mole quantity of trivalent species per litre (the D/T ratio) ration is preferably greater than 1. More preferably D/T is between 2 and 100, and even more preferably D/T is between 2 and 20, and even more preferably D T is between 4 and 10.
  • the ferrous ion concentration at pH 7.5 will decline to no more than 25% of the concentration at pH 6.0.
  • the decline at pH 7.5 will be to no more than 10% and more preferably to no more than 2% of the soluble ferrous ion concentration at pH 6.0.
  • the acid waste (preferably of pH less than 4) comprises divalent cation species including iron and one or more of cobalt, nickel, copper, magnesium, manganese or zinc and trivalent species including iron and optionally also other trivalent species such as aluminium and wherein the process comprises adding alkaline reagents to the acid waste until the final pH of the system is in the range 7-9 or greater, and wherein the reaction conditions are such that ferrous ions in the acid waste are stable with respect to oxidation, until the pH is greater than approximately 7.5.
  • the process further comprises removing the coarse moderately crystalline precipitate formed as a result of the addition of alkaline reagents under the above conditions, leaving a resultant liquor which contains low levels of dissolved metal species.
  • Precipitated salts formed according to the process of this invention can readily be filtered without a settling or flocculation stage.
  • the salts exhibit a coarse, often platey structure, at least in part, whereas ferrihydrite arising from the rapid precipitation of Fe(lll) with carbonate or hydroxide comprises ultra-fine particles frequently having no obvious morphology under electron microscopy.
  • good remediation of heavy metal components can be achieved at the conclusion of a pH ramp starting at the pH of the acid mine drainage (e.g. pH 3.3 for the Berkeley Pit contaminated water) and ending at a pH value in the range 7.5-9.
  • Remediation of acid mine drainage by the method of this invention does not use air sparging, nor does it require significant carbon dioxide sparging for pH adjustment.
  • stratification may occur, whereby the surface layer (e.g. top 2 m) comprises iron as Fe(lll) and the deep layer (below 3 m) comprises iron as Fe(ll).
  • an appropriate divalent/trivalent ratio may be achieved by judicious mixing of waters of deep and surface origin.
  • the recovery of valuable metals such as zinc and copper from the precipitated pyroaurite-like compound can be achieved by solubilisation using acid and/or ammoniacal or other treatments followed by electro-winning, solvent extraction or resin-based recovery methodology.
  • the precipitation reaction of the present invention is carried out in a pipe reactor.
  • a pipe reactor is particularly preferred as it enables a continuous rather than a batch process to be used while excluding oxygen and minimising environmental hazards. By changing the length and diameter of the pipe, various reaction times can be achieved providing good control of the process.
  • the process of this invention can be a batch process or a continuous process.
  • the reactor vessel can comprise one or more continuous stirred tank reactors.
  • the process of the present invention generally allows the undesirable metal values to be substantially removed in a single precipitation process and the precipitate is generally easy to isolate without the use of further chemical additives such as flocculating agents and the like.
  • the precipitate may be collected by any suitable means.
  • a filter, stirred settling pond or lamella thickener may be used to collect the precipitate.
  • Example 1 Remediation of Metal Cations from Berkeley Pit Acid Mine Drainage
  • ALD Advanced Driver Assistance Device
  • HDPE high density polyethylene
  • the HDPE container was opened in a glove box under argon and 200 ml of the Pit water was added to a stoppered 250 ml Metrohm reaction vessel with argon flowing over the fluid surface.
  • the glass stopper of the vessel contained ground glass conical apertures to take a plastic blade stirrer, a glass pH electrode, a plastic microburette with a non- diffusing tip as well as the argon delivery tube.
  • Ambient temperature was about 21 °C.
  • a solution of approximately 1M Na 2 CO 3 was made with argon saturated double deionised water.
  • the sodium carbonate solution was supplied to the burette system of an automatic titrimeter set to a pH stat mode so that on any hydrolysis sufficient alkali would be automatically added to restore the pH upwards to a preset value.
  • the set pH was then raised to 8.5 and a further reaction started while the pH was maintained at this value.
  • the suspension remained dark green. All reaction had ceased after 30 minutes.
  • the reaction vessel which was water jacketed was then heated to about 30°C, the argon flow turned low and air allowed to diffuse into the vessel to allow some oxidation of the products.
  • the pH was again raised to a value of 9 and a long, slow, reaction commenced and lasted about 180 minutes. At the end of this time the colour had changed to a pale orange colour with a brown tinge.
  • the suspended solid phase was iron rich and some oxidation had obviously occurred.
  • the suspension was immediately filtered through a Whatman 41 paper (a fast filtering coarse grade) without the provision of any settling period, and the filtrate was examined by inductively coupled plasma (ICP) spectroscopy for elemental composition.
  • ICP inductively coupled plasma
  • the metal composition of the filtrate by ICP is shown in the Table below, together with the starting values of metals in the acid mine drainage (AMD).
  • X-ray diffraction results on the precipitate showed d spacings at 7.57, 2.57 and 3.77 angstroms. These spacings were compared to the d spacings of takovite, a stable member of the pyroaurite group with basal spacings near to that of green rust (Bernal Desgupta and Mackay, The Oxides and Hydroxides of Iron and their Structural Interrelationships, Clay Minerals Bulletin 1959, 4, 15-30).
  • takovite nickel aluminium hydroxy carbonate
  • the principal spacings are at 7.54, 2.55 and 3.77 angstroms.
  • Example 2 The purpose of this example is to illustrate the process of this invention when the pH-modifying agents (limestone and lime) are added in the powder form.
  • Sample 400 ml fresh pit water collected 6 days before the experiment, sub- sampled and stored in a 500ml autoclave bottle, completely filled and stoppered.
  • Reagent preparation pH modifying agents were powdered one micron CaCO 3 and AR grade CaO.
  • NB arrows going from left to right indicate an upward drift of pH, and vice versa for arrows going from right to left.
  • the dark green brown suspension was filtered and the filtrate and washings were made up to a fixed volume (564 ml) from which 250 ml were taken and bottled for ICP analysis. This was stored in the refrigerator and was re-filtered through a 0.45 ⁇ m filter for analysis.
  • Example 3 The purpose of this example is to illustrate the process of this invention when the sole pH-modifying agent (lime) is added as a suspension.
  • pH modifying agent is 0.731 M CaO suspension (3.2g dispersed in 80 ml distilled water). CaO was finely milled reagent grade.
  • Material preparation 400 ml of the freshly gathered pit water.
  • the residual pit water in the glass bottle was also bubbled with the natural gas for about 10 sec before being closed in an effort to minimise oxidation.
  • the purpose of this example is to illustrate the process of this invention when a shorter reaction time was used.
  • the pH-modifying agents limestone
  • the sample consisted of 400 ml pit water collected 13 days before the experiment and stored in a 500 ml glass autoclave bottle which was completely filled and stoppered.
  • pH modifying agents were 0.1 g/m! one micron CaCO 3 suspension and 0.1g/ml CaO suspension (3.0g dispersed in 30ml distilled water in each case).
  • the CaO was taken from the lower part of the bottle to minimize the risk of having CaO that might have been partially converted to the carbonate.
  • the dark green brown suspension was filtered through a Whatman type 41 paper using a Buchner funnel.
  • the filtrate and washings were made up to volume in a 500 ml volumetric flask. 250 ml was taken and bottled for ICP analysis. This was stored in the refrigerator and re-filtered through a 0.45 micron filter for analysis.
  • the results were as follows:

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  • Life Sciences & Earth Sciences (AREA)
  • Hydrology & Water Resources (AREA)
  • Engineering & Computer Science (AREA)
  • Environmental & Geological Engineering (AREA)
  • Water Supply & Treatment (AREA)
  • Chemical & Material Sciences (AREA)
  • Organic Chemistry (AREA)
  • Removal Of Specific Substances (AREA)

Abstract

L'invention concerne un procédé de traitement d'eaux usées acides ou d'eaux de ruissellement acides, contenant des métaux comprenant des ions ferreux et ferriques, consistant à augmenter le pH des rejets acides à pH 7,5 au moins, par l'addition d'un réactif alcalin, dans des conditions telles que les ions ferreux résistent à l'oxydation en ions ferriques, pour former un précipité qui est ensuite séparé.
PCT/AU1997/000179 1996-03-28 1997-03-21 Procede pour traiter des eaux usees acides Ceased WO1997036829A1 (fr)

Priority Applications (2)

Application Number Priority Date Filing Date Title
US09/155,490 US6139753A (en) 1997-03-21 1997-03-21 Method for treating acidic waste water
AU20184/97A AU704342B2 (en) 1996-03-28 1997-03-21 Method for treating acidic waste water

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
AUPN8955A AUPN895596A0 (en) 1996-03-28 1996-03-28 Method of treatment of waste water
AUPN8955 1996-03-28

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AU (1) AUPN895596A0 (fr)
ID (1) ID16400A (fr)
WO (1) WO1997036829A1 (fr)
ZA (1) ZA972606B (fr)

Cited By (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO1999001383A1 (fr) * 1997-07-02 1999-01-14 Csir Traitement d'eau acide contenant des cations ferreux dissous
WO2001028934A1 (fr) * 1999-10-18 2001-04-26 Inco Limited Procede pour reduire la concentration de metaux et de metalloides dissous dans une solution aqueuse
RU2187463C1 (ru) * 2001-06-06 2002-08-20 Янченко Дмитрий Федорович Способ очистки подземных вод
CN116199267A (zh) * 2023-02-01 2023-06-02 中国科学院南京土壤研究所 一种利用高铁镁酸性矿井水合成的层状双氢氧化物及其制备方法和应用
CN116328710A (zh) * 2023-04-28 2023-06-27 贵州大学 高效去除amd中重金属的生物矿化材料、制备方法及应用
WO2023183965A1 (fr) * 2022-03-30 2023-10-05 Eagle Innovations Pty Ltd Procédés, appareil et additif de traitement

Families Citing this family (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN112321076A (zh) * 2020-10-29 2021-02-05 太原理工大学 一种酸性矿井水的级联处理系统

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US4321149A (en) * 1975-05-30 1982-03-23 Gte Products Corporation Process for removing multivalent metals from waste effluents
WO1983002446A1 (fr) * 1982-01-19 1983-07-21 MÜLLER, German Procede de decontamination des boues naturelles et industrielles
US5169538A (en) * 1991-01-12 1992-12-08 Basf Aktiengesellschaft Removal of nobler metal ions than iron from process and waste waters
US5308501A (en) * 1993-04-02 1994-05-03 Eckert C Edward Treatment system for alkaline or acidic solution containing heavy metals
WO1994018126A1 (fr) * 1993-02-15 1994-08-18 958075 Ontario Inc. Carrying On Business As Eurocan Ventures Procede pour eliminer les ions de metaux lourds de l'eau
US5427691A (en) * 1992-12-02 1995-06-27 Noranda, Inc. Lime neutralization process for treating acidic waters

Patent Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4321149A (en) * 1975-05-30 1982-03-23 Gte Products Corporation Process for removing multivalent metals from waste effluents
WO1983002446A1 (fr) * 1982-01-19 1983-07-21 MÜLLER, German Procede de decontamination des boues naturelles et industrielles
US5169538A (en) * 1991-01-12 1992-12-08 Basf Aktiengesellschaft Removal of nobler metal ions than iron from process and waste waters
US5427691A (en) * 1992-12-02 1995-06-27 Noranda, Inc. Lime neutralization process for treating acidic waters
WO1994018126A1 (fr) * 1993-02-15 1994-08-18 958075 Ontario Inc. Carrying On Business As Eurocan Ventures Procede pour eliminer les ions de metaux lourds de l'eau
US5308501A (en) * 1993-04-02 1994-05-03 Eckert C Edward Treatment system for alkaline or acidic solution containing heavy metals

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DERWENT ABSTRACT, Accession No. 71300W/43, Class D15; & JP,A,50 024 160, (HITACHI KK), 15 March 1975. *
DERWENT ABSTRACTS, Accession No. 85-161543/27, Class D15; & JP,A,60 090 832, (SHIN-NIPPON KINZOKU), 22 May 1985. *
DERWENT ABSTRACTS, Accession No. 86-016480/03, Class D15; & JP,A,60 238 194, (MORIMOTO), 27 November 1985. *
DERWENT ABSTRACTS, Accession No. 86-025531/04, Class D15; & JP,A,60 248 293, (TAMONOI), 7 December 1985. *
DERWENT ABSTRACTS, Accession No. 89-127593/17, Class D15; & JP,A,01 075 093, (MITSUBISHI METAL KK) 20 March 1989. *
JAPIO ONLINE, Abstract 80-061996, Class 13.I; & JP,A,55 061 996, (MITSUBISHI HEAVY IND LTD), 10 May 1980. *
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Cited By (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO1999001383A1 (fr) * 1997-07-02 1999-01-14 Csir Traitement d'eau acide contenant des cations ferreux dissous
US6419834B1 (en) 1997-07-02 2002-07-16 Csir Treatment of acidic water containing dissolved ferrous cations
WO2001028934A1 (fr) * 1999-10-18 2001-04-26 Inco Limited Procede pour reduire la concentration de metaux et de metalloides dissous dans une solution aqueuse
RU2238246C2 (ru) * 1999-10-18 2004-10-20 Инко Лимитед Способ уменьшения концентрации растворенных металлов и металлоидов в водном растворе
RU2187463C1 (ru) * 2001-06-06 2002-08-20 Янченко Дмитрий Федорович Способ очистки подземных вод
WO2023183965A1 (fr) * 2022-03-30 2023-10-05 Eagle Innovations Pty Ltd Procédés, appareil et additif de traitement
CN116199267A (zh) * 2023-02-01 2023-06-02 中国科学院南京土壤研究所 一种利用高铁镁酸性矿井水合成的层状双氢氧化物及其制备方法和应用
CN116328710A (zh) * 2023-04-28 2023-06-27 贵州大学 高效去除amd中重金属的生物矿化材料、制备方法及应用

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ZA972606B (en) 1998-09-28
AR006443A1 (es) 1999-08-25
ID16400A (id) 1997-09-25
AUPN895596A0 (en) 1996-04-26

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