WO1994002417A2 - Procede d'extraction de sodium dans les matieres solides contaminees par du sodium - Google Patents

Procede d'extraction de sodium dans les matieres solides contaminees par du sodium Download PDF

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Publication number
WO1994002417A2
WO1994002417A2 PCT/GB1993/001513 GB9301513W WO9402417A2 WO 1994002417 A2 WO1994002417 A2 WO 1994002417A2 GB 9301513 W GB9301513 W GB 9301513W WO 9402417 A2 WO9402417 A2 WO 9402417A2
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WO
WIPO (PCT)
Prior art keywords
sodium
process according
acid
cation exchanger
solids
Prior art date
Application number
PCT/GB1993/001513
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English (en)
Other versions
WO1994002417A3 (fr
Inventor
Graham Wightman
Original Assignee
Davy Mckee (Stockton) Limited
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 Davy Mckee (Stockton) Limited filed Critical Davy Mckee (Stockton) Limited
Priority to AU45796/93A priority Critical patent/AU670608B2/en
Priority to EP93916106A priority patent/EP0613453A1/fr
Publication of WO1994002417A2 publication Critical patent/WO1994002417A2/fr
Publication of WO1994002417A3 publication Critical patent/WO1994002417A3/fr

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Classifications

    • C—CHEMISTRY; METALLURGY
    • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
    • C22B—PRODUCTION AND REFINING OF METALS; PRETREATMENT OF RAW MATERIALS
    • C22B26/00—Obtaining alkali, alkaline earth metals or magnesium
    • C22B26/10—Obtaining alkali metals
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
    • B01J39/00—Cation exchange; Use of material as cation exchangers; Treatment of material for improving the cation exchange properties
    • B01J39/04—Processes using organic exchangers
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
    • B01J47/00—Ion-exchange processes in general; Apparatus therefor
    • B01J47/011—Ion-exchange processes in general; Apparatus therefor using batch processes
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
    • B01J49/00—Regeneration or reactivation of ion-exchangers; Apparatus therefor
    • B01J49/05—Regeneration or reactivation of ion-exchangers; Apparatus therefor of fixed beds
    • B01J49/06—Regeneration or reactivation of ion-exchangers; Apparatus therefor of fixed beds containing cationic exchangers
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B09—DISPOSAL OF SOLID WASTE; RECLAMATION OF CONTAMINATED SOIL
    • B09C—RECLAMATION OF CONTAMINATED SOIL
    • B09C1/00—Reclamation of contaminated soil
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B09—DISPOSAL OF SOLID WASTE; RECLAMATION OF CONTAMINATED SOIL
    • B09C—RECLAMATION OF CONTAMINATED SOIL
    • B09C1/00—Reclamation of contaminated soil
    • B09C1/02—Extraction using liquids, e.g. washing, leaching, flotation
    • C—CHEMISTRY; METALLURGY
    • C01—INORGANIC CHEMISTRY
    • C01F—COMPOUNDS OF THE METALS BERYLLIUM, MAGNESIUM, ALUMINIUM, CALCIUM, STRONTIUM, BARIUM, RADIUM, THORIUM, OR OF THE RARE-EARTH METALS
    • C01F7/00—Compounds of aluminium
    • C01F7/02—Aluminium oxide; Aluminium hydroxide; Aluminates
    • C01F7/04—Preparation of alkali metal aluminates; Aluminium oxide or hydroxide therefrom
    • C01F7/06—Preparation of alkali metal aluminates; Aluminium oxide or hydroxide therefrom by treating aluminous minerals or waste-like raw materials with alkali hydroxide, e.g. leaching of bauxite according to the Bayer process
    • C01F7/066—Treatment of the separated residue
    • C—CHEMISTRY; METALLURGY
    • C01—INORGANIC CHEMISTRY
    • C01F—COMPOUNDS OF THE METALS BERYLLIUM, MAGNESIUM, ALUMINIUM, CALCIUM, STRONTIUM, BARIUM, RADIUM, THORIUM, OR OF THE RARE-EARTH METALS
    • C01F7/00—Compounds of aluminium
    • C01F7/02—Aluminium oxide; Aluminium hydroxide; Aluminates
    • C01F7/46—Purification of aluminium oxide, aluminium hydroxide or aluminates

Definitions

  • This invention relates to a process for the removal of sodium values from sodium contaminated solids, such as red mud.
  • Red mud is the major waste product from the production of aluminium, being the residue remaining after leaching of bauxite by the Bayer process.
  • bauxite is heated under pressure with sodium hydroxide.
  • the aluminium oxide reacts to form the aluminate ion which remains in solution.
  • the solid impurities are removed by filtration and are known as red mud.
  • Aluminium values in the sodium aluminate solution are reprecipitated upon cooling the filtered sodium aluminate solution by seeding with a crystal of alumina trihydrate: extraction A1 2 0 3 .3H 2 0 + 2NaOH 2NaA10 2 + 4H 2 0 (1). decomposition
  • the resulting alumina trihydrate precipitate can then be calcined to yield alumina:
  • Aluminium is the non-ferrous metal produced in largest quantity throughout the world. It is estimated that between 40 and 50 million tonnes per year of red mud are produced, essentially all of which is stored as landfill. It is also estimated that this quantity of red mud contains the equivalent of about 2 million tonnes of sodium hydroxide.
  • the red mud is a mixture of oxides, such as those of iron, titanium and calcium, together with desilication products resulting from the Bayer leaching of the bauxite ore.
  • desilication products are sodium alumino-silicates, or sodalites as they are alternatively called, which act as ion exchange compounds for sodium.
  • sodium slowly leaches from the red mud and produces a highly alkaline residue, typically having a pH of 12 or more.
  • red mud is dumped without treatment, considerable pollution will occur since rain water run off from, and ground water contact with, the red mud will lead to leaching of sodium with accompanying impact on the environment. As a result, soil under and around an exposed dump of red mud will become contaminated with sodium values. There is also difficulty in rehabilitating red mud lagoons because, for example, revegetation is hindered by the alkalinity and red mud is slow to settle and to undergo dewatering. Moreover the presence of sodium in the red mud prevents its finding a use as a raw material for other processes.
  • the red mud When the neutralised red mud contains reaction products which include calcium or other metal salts of low solubility, the red mud will be contaminated by anions that may be detrimental to the storage of the neutralised red mud or to the use thereof as a raw material for other processes.
  • the neutralised red mud will contain calcium sulphate which has a solubility of about 2 gpl and which will continue to leach slowly from the neutralised red mud.
  • S0 2 will be released during calcination.
  • Alumina produced in the Bayer process may also be contaminated with sodium values.
  • Another potential source of alkaline pollution of the environment due to sodium contamination is steel plant dust from a sinter plant, blast furnace or a steelmaking plant.
  • ion exchange resins to absorb metal values, such as sodium ions, from solutions thereof is well known.
  • a problem can arise in regeneration of ion exchange resins when the resin has been loaded with metal values using a solution that contains finely divided particulate matter or a solute, such as a calcium salt, which tends to yield a precipitate in finely divided form. This difficulty in regeneration can be attributed at least in part to a blockage of pores in the resin beads.
  • the present invention accordingly seeks to provide a viable process for removal of sodium values from red mud and other sodium contaminated solids (such as alumina, alkali washed coal, sodium contaminated soil, for example contaminated soil from the neighbourhood of red mud dumps, and steel plant dusts), which will reduce the sodium content of the red mud or other solids and hence minimise the pollution problems associated with storage of the treated red mud or other solids, as well as potentially yielding useful products from the metal-containing residues and a source of sodium ions suitable for production of, for example, sodium hydroxide for recycle to the Bayer process.
  • red mud and other sodium contaminated solids such as alumina, alkali washed coal, sodium contaminated soil, for example contaminated soil from the neighbourhood of red mud dumps, and steel plant dusts
  • the invention further seeks to provide a process for regenerating sodium loaded cation exchange resins, particularly such loaded resins that are also loaded with calcium values, that results in an eluate with less acidity and a higher sodium tenor than conventional regeneration procedures and that is more suitable for disposal or for further treatment for removal of sodium values.
  • a process for the removal of sodium values from sodium contaminated solids which comprises contacting a slurry of sodium contaminated solids with a particulate cation exchanger, separating sodium loaded cation exchanger, regenerating said sodium loaded cation exchanger to liberate sodium values therefrom, and recycling resulting regenerated cation exchanger for contact with further slurry of sodium contaminated solids.
  • the process of the invention is applicable to treatment of a wide variety of sodium contaminated solids, including red mud, sodium contaminated soil (e.g. soil from the vicinity of a red mud dump) , alumina produced by the Bayer process, coal that has been washed with a caustic soda or soda ash solution, and steel plant dusts. It is of particular applicability to treatment of red mud.
  • the particles are very fine; typically the particles are smaller than about 0.1 mm and 80% or more of the particles may be smaller than about 10 ⁇ m.
  • the particulate cation exchanger In order to enable separation of the red mud or other solid being treated and the cation exchanger by particle size, the particulate cation exchanger preferably has a significantly larger particle size than that of the red mud or other solid being treated. Hence in the treatment of red mud the particulate cation exchanger preferably has a particle size in the range of from about 0.1 mm to about 5 mm or more, more preferably from about 0.5 mm to about 2 mm.
  • separation by particle size is not the only method of separating cation exchangers from slurries of red mud or other solids and the use of particulate cation exchangers having the specified range of particle sizes is not an essential feature of the invention.
  • cation exchangers there can be mentioned cation exchange resins, chelating resins, and zeolites.
  • Cation exchange resins typically comprise polymeric chains, such as polystyrene chains, having pendant functional groups, typically acidic groups such as sulphonic acid groups, carboxylic acid groups, or phenolic groups. Such resins may have a macroreticular structure or may have a gel-like structure. They may be classed as strong cation exchange resins, such as those resins containing pendant sulphonic acid groups, or as weak cation exchange resins, such as those containing pendant carboxylic acid groups. Suitable cation exchange resins include, but are not limited to, Amberlite IR120, Amberlite 200C, Purolite C105, Purolite C106, and Purolite 160TL. (The words “Amberlite” and “Purolite” are trade marks). Such resins typically have an ion exchange capacity ranging from about 1.7 to about 4 equivalents per litre.
  • the red mud or other sodium contaminated solid is supplied to the process in the form of a slurry containing typically from about 50 gpl to about 250 gpl up to about 500 gpl, e.g. about 200 gpl, of red mud solids or other solids.
  • the solids concentration is as high as is possible so as to enable the equipment to be as compact as possible but not so high that its viscosity renders the slurry insufficiently fluid for handling.
  • the slurrying liquid is conveniently water.
  • the red mud or other solid being treated can be contacted batchwise as a slurry with the cation exchanger.
  • the solids:cation exchanger mass ratio preferably ranges from about 1:1 up to about 10:1 or more, e.g. 20:1. More preferably, however, it ranges from about 1.5:1 to about 5:1.
  • the pH of the pulp can be controlled by selection of the solids:cation exchanger mass ratio.
  • the red mud or other solid being treated is contacted with the particulate cation exchanger in a contactor of the type used in resin-in-pulp or carbon-in-pulp metallurgical processes and the red mud or other solid is continuously supplied to the contactor in the form of a slurry.
  • the red mud slurry (or other solid slurry) and the cation exchanger may pass in countercurrent through the contactor.
  • the solids:cation exchanger volume mass ratio is preferably from about 1:1 up to about 10:1 or more, e.g. 20:1, even more preferably from about 1.5:1 to about 5:1.
  • the pH of the pulp can be controlled by selection of an appropriate solids:cation exchanger mass flow ratio.
  • the sodium contaminated solid comprises red mud.
  • red mud For convenience the following description refers in the main to treatment of red mud.
  • other types of sodium contaminated solids such as sodium contaminated soil, alumina produced by the Bayer process, or steel plant dust, can be treated in place of red mud by the process of the invention
  • the Na + loaded resin can be regenerated in any convenient manner. However, for recycle for further use in the process, of the invention it needs to be converted to the H form. Thus, for example, it can be regenerated by treatment with a regenerant solution containing an organic or inorganic acid. Alternatively it can be treated with a regenerant solution containing cations other than Na + ions.
  • organic acids there can be mentioned formic acid and acetic acid.
  • Hydrochloric acid, sulphuric acid, sulphurous acid, phosphoric acid are examples of inorganic acids.
  • Other regenerant solutions that can be used include solutions containing calcium ions, such as calcium chloride, or a magnesium salt, such as magnesium chloride.
  • the calcium or magnesium loaded cation exchange resin should, however, be converted by treatment with an acid to the H + form before return to the process of the invention.
  • the loaded resin is regenerated using a regenerant solution containing an acid, such as sulphuric acid, and also sodium ions, for example, a solution containing sodium sulphate and sulphuric acid.
  • an acid such as sulphuric acid
  • sodium ions for example, a solution containing sodium sulphate and sulphuric acid.
  • the mole ratio of sodium ions to sulphuric acid is desirably less than about 5:1.
  • the process can be operated in batch fashion by stirring a given quantity of red mud in water with an appropriate quantity of cation exchange resin in the H form, followed by filtration through a mesh filter of appropriate mesh size which permits passage of red mud particles but retention of the Na + loaded resin, regeneration of the Na + loaded resin, and recycle of regenerated resin in H + form for further use.
  • the process is conducted on a continuous basis using contactors of the type conventionally used in resin-in-pulp or carbon-in-pulp metallurgical processes for recovery of metal values, such as uranium or gold values.
  • Stirred contactors can be used.
  • An example of such apparatus is described, for example, in GB-A-2106806.
  • one or more such contactors connected in series can be used with a continuous flow of red mud slurry (pulp) passing through the contactor or train of contactor? while the resin is transferred countercurrent to the julp flow in order to remove and recover the sodium values from the red mud.
  • the sodium loaded resin is then transferred to another contactor or train of contactors operating in a regeneration mode in order to regenerate the hydrogen form of the resin for recycle and to release the sodium and calcium values therefrom.
  • a regeneration mode e regenerant solution and sodium-loaded resin can pass countercurrent to one another through the contactor or train of contactors.
  • the on line phase may be continued for a particular contactor until the resin is loaded to its equilibrium capacity with sodium and other metal values, it will usually be preferred to stop short of this point when the resin has been loaded with sodium and other metal values to, for example, about 90% up to about 95% or more of its equilibrium ion exchange capacity.
  • the present invention provides a process for regenerating a cation exchange resin loaded with metal values selected from sodium values, calcium values, and mixtures thereof, which comprises contacting said loaded resin with a regenerant solution comprising a mixture of sodium ions and an acid.
  • the acid may be for example, sulphuric acid or sulphorous acid.
  • a solution containing a mixture of sodium sulphate and sulphuric acid Preferably the sodium loaded resin is one which has been used for removal of sodium values from red mud.
  • a resin may be, for example, a weak acid cation exchange resin.
  • the acid used may be sulphurous acid but is preferably sulphuric acid.
  • the ratio of sodium sulphate to sulphuric acid may range, for example, up to about 5:1 on a molar basis, preferably in the range of from about 0.5:1 to about 2:1.
  • the concentration of sulphuric acid is typically from about 5 gpl to about 500 gpl, preferably from about 10 gpl to about 200 gpl.
  • the pH of the eluate resulting from regeneration of the sodium loaded cation exchanger with the regenerant solution can be controlled by control of the volume flow rate of the regenerant solution through the sodium loaded cation exchanger. Alternatively it can be controlled by control of the composition of the regenerant solution applied to the cation exchanger.
  • the cation exchange resin takes up calcium values in addition to sodium values.
  • calcium sulphate is formed in the course of regeneration of the resin using a sulphuric acid- containing regenerant calcium sulphate. This tends to form a supersaturated solution in the regenerant eluate and to crystallise out therefrom. It is an advantage of using a mixed sodium sulphate/sulphuric acid regenerant solution that the crystals of calcium sulphate formed are finer than those formed when sulphuric acid is used alone.
  • the sodium loaded eluate obtained upon regeneration of the loaded resin can be treated in any desired manner for the recovery of sodium hydroxide or sodium salts, e.g. sodium sulphate, therefrom.
  • the sodium loaded eluate can be subjected to crystallisation or to electrolysis in a membrane cell such as that developed by Imperial Chemical Industries p.I.e. or by the Aquatech Systems Division of Allied-Signal Inc. of 7 Powder Horn Drive, P.O. Box 4904, Warren, NJ 07059-5191, U.S.A., in order to recover in a commercially usable form the sodium values removed from the red mud.
  • Such sodium values can be used, for example, for recycle to the Bayer process.
  • the eluate from the regeneration stage is less acidic than that obtained when sulphuric acid is used alone. Hence electrolysis of the eluate solution is facilitated.
  • the eluate is to be discharged from the plant or crystallised, less neutralisation is required.
  • the sodium tenor of the eluate is higher when using a mixed Na 2 SO j /H 2 SO ij eluant in the regeneration step. This makes subsequent recovery of sodium values easier by crystallisation, electrolysis or other treatment steps.
  • An additional advantage of the use of a mixed Na 2 S ⁇ 4/H 2 S ⁇ 4 regenerant solution is that the pH of the eluate changes dramatically once the peak of the elution curve is passed.
  • the pH of the eluate is typically in the range from about 4 to about 7 and requires addition of only a minor amount of an alkali, such as lime or sodium carbonate, to produce a neutral solution which can be treated or discharged.
  • the pH of the eluate drops below about 4.
  • the resulting eluate can be mixed with further sulphuric acid and/or sodium sulphate to produce an eluant solution for regeneration of a subsequent batch of loaded resin.
  • a split elution process can be advantageously used.
  • the use of a mixed Na ⁇ O ⁇ / ⁇ SO ⁇ regenerant solution may assist calcium removal by forming calcium bisulphate, which is soluble, in place of insoluble calcium sulphate.
  • calcium bisulphate may eventually crystallise as calcium sulphate, possibly as a result of the presence of a seed crystal of calcium sulphate, this will tend to occur away from the resin. Hence blockage of resin pores will be reduced.
  • Treated red mud resulting from the process of the invention may be substantially free from leachable sodium values or may have a markedly reduced leachable sodium content and can be used for addition to cement, as a fluxing agent, as a building material feedstock, or as a source of iron and/or other metal values.
  • Figure 1 is a flow diagram of the process of the invention used for treatment of red mud
  • Figure 2 is a series of graphs showing the effect, when using a strong cation exchange resin, of changes in the pulp:resin ratio upon the change in sodium concentration in the solids with time in the course of treatment of red mud by the process of the invention;
  • Figure 3 is a series of graphs showing the change of sodium content of the solids with time when using a weak cation exchange resin at various pulp/resin ratios in a red mud treatment process conducted in accordance with the teachings of the invention
  • Figure 4 is a graph showing how elution of calcium ions in three successive tests varies with the volume of eluate during resin regeneration;
  • Figure 5 is a graph showing acid utilisation in the same three tests.
  • Figure 6 plots two graphs showing elution of sodium ions from a loaded resin using, on the one hand, sulphuric acid and, on the other hand, a mixture of sodium sulphate and sulphuric acid for resin regeneration;
  • Figure 7 provides a comparison of free acid concentration during resin regeneration determined by titration with the corresponding calculated concentrations
  • Figure 8 is a graph of pH against eluate analysis during resin regeneration
  • Figure 9 is a plot of sodium distribution as sulphate and bisulphate during the course of elution during resin regeneration
  • Figure 10 shows a graph of acid utilisation during regeneration of a sodium loaded weak cation resin, assuming (a) sodium sulphate formation and (b) sodium bisulphate formation;
  • Figure 11 is a flow diagram of a process for regeneration of sodium loaded cation exchange resin produced by treatment of red mud according to the process of the invention.
  • Example 1 The invention is further illustrated in the following Examples in which all percentages are by weight unless otherwise stated.
  • Example 1 The invention is further illustrated in the following Examples in which all percentages are by weight unless otherwise stated.
  • the low mass balance can be attributed to incomplete elution.
  • Example 2 The procedure of Example 2 was repeated using 595 g dry weight of red mud dispersed in water to form 2.55 litres of pulp. This was stirred with 1000 ml of a weakly cationic exchange resin, i.e. Purolite C105. This resin is described by its manufacturers as being of gel type. The results of this stirring test are summarised in Table IV. Table IV
  • ND means "not detected” .
  • the sodium balance was as set out in Table VI .
  • a weak cation exchange resin namely Purolite C105
  • Purolite C105 was loaded, at a 10:1 pulp:resin ratio, to 31.9 g sodium per litre of resin using a slurry of red mud.
  • a portion of the loaded resin was regenerated using (i) 50 gpl sulphuric acid as regenerant and (ii) a regenerant solution containing 35 gpl sulphuric acid plus 22 gpl sodium sulphate, both at 5 bed volumes (BV) per hour.
  • the sodium sulphate figures given in Table VIII exclude the 22 gpl sodium sulphate already present in the eluant; in other words the total sodium sulphate for aliquot 1A was 50.19 gpl, corresponding to a total sodium content of 16.26 gpl.
  • the Na 2 S0 4 figures exclude the 22 gpl Na 2 S0 4 already present in the eluant solution and the H S0 4 figures are calculated figures. Washing with 2 litres of 100 gpl HCl to dissolve the precipitated crystals of CaS0 gave a liquor with a sodium content of 0.52 gpl and a calcium content of 0.27 gpl.
  • Figure 6 illustrates figures for the sodium concentration of the eluate (less the sodium initially present in eluant (ii) ) measured after different numbers of bed volumes of eluate have emerged from the resin bed.
  • Figure 7 shows a comparison of the free acid in the eluate during regeneration of a sodium loaded resin using a mixture of Na 2 S0 4 (22 gpl) and H 2 S0 4 (35 gpl) as determined by titration as compared with concentrations determined by calculation assuming (a) that sodium forms sodium bisulphate and (b) that sodium forms sodium sulphate, while in either case calcium forms calcium sulphate.
  • Figure 7 indicates that sodium in the eluate initially forms sodium bisulphate until all the free acid has been removed, whereupon sodium liberated in the eluate forms sodium sulphate.
  • the titrations at the start and end of the elution indicate the presence of 30 to 35 gpl free acid, showing that the Na S0 4 /H 2 S0 eluant behaves as free acid rather than forming sodium bisulphate.
  • Figure 8 shows graphs of the eluate analysis and of pH plotted against numbers of bed volumes of eluant (regenerant) passing through a bed of sodium loaded weak cation exchange resin, loaded according to the method of Example 2 and eluted according to the procedure of Example 5(c). It is notable how the pH value drops dramatically at about bed volume 2E, although the decline in NaHS0 4 concentration is somewhat less marked. This sudden change in pH may be used in a split elution process to mark the change between a near neutral eluate which can be processed further or discharged and a more acidic eluate suitable for recycle as eluant.
  • Figure 9 shows the measured sodium content of the eluate from elution using a mixed H 2 S0 4 /Na 2 S0 4 eluant together with the calculated proportions of the sodium present as sulphate and as bisulphate. Superimposed are the recorded pH and the quantity of alkali required to neutralise the excess acid and attain pH7. Over the first bed volume virtually no alkali is needed to achieve pH7. Between bed volumes 2 and 3 the peak of the elution is passed and the eluted sodium reports as sodium bisulphate with a corresponding drop in pH and increase in alkali requirement to achieve pH7. In this example elution would be split as pH dropped below 4 and very little alkali would be required to neutralise the first eluate, equivalent to less than 1 gpl acid in the combined eluate.
  • Figure 10 shows the calculated acid utilisation assuming (a) that all the sodium eluted forms sodium bisulphate and (b) that all the sodium eluted forms sodium sulphate.
  • This Figure shows the results of a wide range of elutions of resin loaded under various pulp/resin ratios. Each peak corresponds to an individual elution curve. The horizontal axis represents eluate volume on an arbitrary scale. The peak acid elutions are comparable for 50 gpl acid at 5 bed volumes (BV) per hour and are not dependent on pulp/resin ratio during loading. Similarly at 35 gpl acid, also at 5 bed volumes per hour, the acid utilisation is similar to that at 50 gpl acid, although it is higher at 1 bed volume per hour. Consequently the higher utilisations achieved in the mixed eluant system are attributable to the synergistic effect observed, which is contrary to normal observations when the presence of a cation inhibits elution of that cation.
  • FIG. 11 there is illustrated a possible reaction scheme for regeneration of batches of sodium loaded cation exchange resin which has been used for treatment of red mud in accordance with the invention.
  • a batch of sodium loaded resin is regenerated using a mixture of a solution of Na 2 S0 4 /H S0 and eluate (herein called "Second eluate") having a pH, at the flow rate and eluant concentration selected, typically less than about 3 to about 4 obtained from the later stages of regeneration of a previous batch of sodium loaded resin.
  • the initial eluate from the regeneration vessel has a pH typically greater than about 4. That initial eluate requires minimal neutralisation to achieve pH 7.
  • the pH of the collected initial eluate is 4.8
  • addition of sodium carbonate equivalent to 0.05 gpl of cone. H 2 S0 4 suffices to achieve a pH of 7.
  • the eluate collected in these later stages forms the second eluate mentioned above.
  • the initial eluate possibly after neutralisation, can be discharged or can be subjected to further processing, e.g. crystallisation to produce sodium sulphate or electrohydrolysis to produce sodium hydroxide and sulphuric acid.
  • the raffinate from such a crystallisation procedure or the acid stream from the electrohydrolysis step can be recycled to provide eluant for elution of further sodium loaded resin.
  • the species present in the initial eluate can be described as an NaHS0 4 /Na 2 S0 4 solution.
  • the species present will be NaHS0 4 , Na 2 S0 4 and H 2 S0 4 and at this point the pH drops below 4.

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Abstract

L'élimination du sodium contenu dans des matières solides contaminées par le sodium, par exemple dans de la boue rouge, consiste à mettre une boue liquide desdites matières solides en contact avec un échangeur cationique particulaire, l'échange se déroulant à une vitesse supérieure à celle du procédé de lavage par l'eau ou par une solution acide. Lorsqu'on utilise une solution de sulfate de sodium mélangé à un acide, par exemple de l'acide sulfurique, la régénération de la résine chargée en sodium s'effectue de manière plus efficace que dans le cas de l'utilisation d'une solution d'acide sulfurique.
PCT/GB1993/001513 1992-07-21 1993-07-19 Procede d'extraction de sodium dans les matieres solides contaminees par du sodium WO1994002417A2 (fr)

Priority Applications (2)

Application Number Priority Date Filing Date Title
AU45796/93A AU670608B2 (en) 1992-07-21 1993-07-19 Process for the removal of sodium values from sodium contaminated solids
EP93916106A EP0613453A1 (fr) 1992-07-21 1993-07-19 Procede d'extraction de sodium dans les matieres solides contaminees par du sodium

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GB929215438A GB9215438D0 (en) 1992-07-21 1992-07-21 Process
GB9215438.4 1992-07-21

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WO1994002417A2 true WO1994002417A2 (fr) 1994-02-03
WO1994002417A3 WO1994002417A3 (fr) 1994-04-28

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CA (1) CA2132638A1 (fr)
GB (1) GB9215438D0 (fr)
WO (1) WO1994002417A2 (fr)

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
FR2746786A1 (fr) * 1996-04-01 1997-10-03 Pechiney Aluminium Procede de recuperation du sodium contenu dans les residus alcalins industriels
WO2009009824A1 (fr) * 2007-07-13 2009-01-22 Alcoa Of Australia Limited Procédé de contrôle de la précipitation de l'alumine
CN110194545A (zh) * 2019-06-26 2019-09-03 浙江中金格派锂电产业股份有限公司 一种废水中镍、钴重金属与镁分离、富集和回收工艺

Families Citing this family (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5717406A (en) * 1995-06-07 1998-02-10 Sanconix Inc. Enhanced position calculation

Citations (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2689229A (en) * 1951-12-04 1954-09-14 Standard Oil Dev Co Regeneration of ion-exchange materials
US3403097A (en) * 1965-03-05 1968-09-24 Asahi Chemical Ind Process for regeneration of cation exchange resin
GB1208217A (en) * 1968-05-13 1970-10-07 Roumanian Minister Of Electric Regeneration of ion-exchange resins
CA1108319A (fr) * 1977-11-18 1981-09-01 Horst Pohland Elimination des boues thixotropiques
GB2106806A (en) * 1981-10-02 1983-04-20 Davy Mckee Apparatus for separating particulate materials of different particle sizes
GB2130109A (en) * 1982-06-28 1984-05-31 Mckee David Inclined screen
EP0253635A1 (fr) * 1986-07-16 1988-01-20 Alcan International Limited Hydrates d'alumine

Family Cites Families (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
SU387723A1 (ru) * 1970-11-30 1973-06-22 СПОСОБ очистки ТРАВИЛЬНЫХ РАСТВОРОВ
US3928541A (en) * 1972-09-05 1975-12-23 Huber Corp J M Amorphous precipitated siliceous pigments for cosmetic or dentrifrice use and methods for their production
JPS57149805A (en) * 1981-03-06 1982-09-16 Showa Alum Ind Kk Manufacture of inorganic oxide or hydroxide freed of ionic impurity

Patent Citations (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2689229A (en) * 1951-12-04 1954-09-14 Standard Oil Dev Co Regeneration of ion-exchange materials
US3403097A (en) * 1965-03-05 1968-09-24 Asahi Chemical Ind Process for regeneration of cation exchange resin
GB1208217A (en) * 1968-05-13 1970-10-07 Roumanian Minister Of Electric Regeneration of ion-exchange resins
CA1108319A (fr) * 1977-11-18 1981-09-01 Horst Pohland Elimination des boues thixotropiques
GB2106806A (en) * 1981-10-02 1983-04-20 Davy Mckee Apparatus for separating particulate materials of different particle sizes
GB2130109A (en) * 1982-06-28 1984-05-31 Mckee David Inclined screen
EP0253635A1 (fr) * 1986-07-16 1988-01-20 Alcan International Limited Hydrates d'alumine

Non-Patent Citations (4)

* Cited by examiner, † Cited by third party
Title
CHEMICAL ABSTRACTS, vol. 50, no. 19, 1959, Columbus, Ohio, US; abstract no. 18346 f, V.P. MELESHKO 'Use of sulfuric acid in the regeneration of cationic filters used in deep desalting of water.' & ZHUR. PRIKLAD KHIM vol. 32 , 1959 pages 1230 - 1238 *
CHEMICAL ABSTRACTS, vol. 81, no. 2, 15 July 1974, Columbus, Ohio, US; abstract no. 6093b, A.D. SMETANICH 'Purification of etching solutions.' page 135 ; & SU,A,387 723 (ALL-UNION SCIENTIFIC RESEARCH INSTITUTE OF WATER SUPPLY) 22 June 1973 *
DATABASE WPI Week 8243, Derwent Publications Ltd., London, GB; AN 82-91156E & JP,A,57 149 805 (SHOWA KEIKINZOKU) 16 September 1982 *
JOURNAL OF SCIENTIFIC AND INDUSTRIAL RESEARCH vol. 42, no. 2 , February 1983 pages 87 - 108 R.S. THAKUR ET AL. 'Utilisation of red mud: Part I - Analysis and utilization as raw material for absorbents, building materials, catalysts, fillers, paints and pigments.' *

Cited By (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
FR2746786A1 (fr) * 1996-04-01 1997-10-03 Pechiney Aluminium Procede de recuperation du sodium contenu dans les residus alcalins industriels
WO1997036823A1 (fr) * 1996-04-01 1997-10-09 Aluminium Pechiney Procede de recuperation du sodium contenu dans les residus alcalins industriels
AU720685B2 (en) * 1996-04-01 2000-06-08 Aluminium Pechiney Process for recovering the sodium contained in industrial alkaline waste
US6110377A (en) * 1996-04-01 2000-08-29 Aluminum Pechiney Process for recovering the sodium contained in industrial alkaline waste
WO2009009824A1 (fr) * 2007-07-13 2009-01-22 Alcoa Of Australia Limited Procédé de contrôle de la précipitation de l'alumine
CN110194545A (zh) * 2019-06-26 2019-09-03 浙江中金格派锂电产业股份有限公司 一种废水中镍、钴重金属与镁分离、富集和回收工艺
CN110194545B (zh) * 2019-06-26 2021-04-27 浙江中金格派锂电产业股份有限公司 一种废水中镍、钴重金属与镁分离、富集和回收工艺

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AU670608B2 (en) 1996-07-25
AU4579693A (en) 1994-02-14

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