WO1996033133A1 - Procede de traitement de sulfate ferreux - Google Patents

Procede de traitement de sulfate ferreux Download PDF

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Publication number
WO1996033133A1
WO1996033133A1 PCT/FI1996/000198 FI9600198W WO9633133A1 WO 1996033133 A1 WO1996033133 A1 WO 1996033133A1 FI 9600198 W FI9600198 W FI 9600198W WO 9633133 A1 WO9633133 A1 WO 9633133A1
Authority
WO
WIPO (PCT)
Prior art keywords
cement
ferrous sulphate
weight
product
limestone
Prior art date
Application number
PCT/FI1996/000198
Other languages
English (en)
Inventor
Bo-Erik Eriksson
Harri Mattila
Original Assignee
Finnsementti Oy
Kemira Pigments Oy
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 Finnsementti Oy, Kemira Pigments Oy filed Critical Finnsementti Oy
Priority to EP96910049A priority Critical patent/EP0821656A1/fr
Publication of WO1996033133A1 publication Critical patent/WO1996033133A1/fr

Links

Classifications

    • C—CHEMISTRY; METALLURGY
    • C04—CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
    • C04B—LIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE; CERAMICS; REFRACTORIES; TREATMENT OF NATURAL STONE
    • C04B22/00—Use of inorganic materials as active ingredients for mortars, concrete or artificial stone, e.g. accelerators, shrinkage compensating agents
    • C04B22/08—Acids or salts thereof
    • C04B22/14—Acids or salts thereof containing sulfur in the anion, e.g. sulfides
    • C04B22/142—Sulfates
    • C04B22/149—Iron-sulfates
    • C—CHEMISTRY; METALLURGY
    • C01—INORGANIC CHEMISTRY
    • C01G—COMPOUNDS CONTAINING METALS NOT COVERED BY SUBCLASSES C01D OR C01F
    • C01G49/00—Compounds of iron
    • C01G49/14—Sulfates
    • C—CHEMISTRY; METALLURGY
    • C04—CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
    • C04B—LIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE; CERAMICS; REFRACTORIES; TREATMENT OF NATURAL STONE
    • C04B2111/00—Mortars, concrete or artificial stone or mixtures to prepare them, characterised by specific function, property or use
    • C04B2111/00034—Physico-chemical characteristics of the mixtures
    • C04B2111/00112—Mixtures characterised by specific pH values
    • C—CHEMISTRY; METALLURGY
    • C04—CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
    • C04B—LIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE; CERAMICS; REFRACTORIES; TREATMENT OF NATURAL STONE
    • C04B2111/00—Mortars, concrete or artificial stone or mixtures to prepare them, characterised by specific function, property or use
    • C04B2111/10—Compositions or ingredients thereof characterised by the absence or the very low content of a specific material
    • C04B2111/1075—Chromium-free or very low chromium-content materials
    • C04B2111/1081—Chromium VI, e.g. for avoiding chromium eczema

Definitions

  • the object of the present invention is a method for trea ⁇ ting ferrous sulphate for the preparation of ferrous sul- phate hydrate which can be used in cement manufacture for the reduction of chromium.
  • cement is manufactured from limestone, sili ⁇ cate, iron and aluminium minerals together with optional fluorine and sulphur correction materials, which are ground and mixed homogenously and thereafter burned to form so called cement clinker.
  • Cement also contains chro ⁇ mium compounds, which on contact with water, for example in concrete production, is converted to the Cr 6+ -form. This soluble chromate is undesirable as it can cause al ⁇ lergies in persons who come into contact with the cement- water mixture.
  • ferrous sulphate in order to reduce the Cr 6+ -content, to add ferrous sulphate to the dry cement clinker to reduce Cr 6+ to Cr 3+ , which reduced form is practically insoluble in the cement-water mixtu ⁇ re.
  • the added amount ferrous sulphate is generally in the range of 0.5 to 1 % by weight of the cement clinker.
  • Ferrous sulphate has a tendency to absorb water wherefore it is difficult to handle as such, for example to pump or to blow.
  • Ferrous sulphate is, however, commercially avai ⁇ lable e.g. in the form of its heptahydrate provided with an oxidation preventing coating, which coating imparts to the product also desirable flow characteristics.
  • the use of such a coated preparation is, however, expensive ta ⁇ king into account the large amounts needed in cement ma ⁇ nufacture.
  • Mixing of gypsum or fly ash in the ferrous sulphate is mentioned as a particularly suitable chemical method, whereas calcium oxide or cement alone are not said to give optimal re ⁇ sults.
  • the problem underlying the present invention was to find a material for chromium reduction which, on the one hand, contains only such components that are "familiar" in ce ⁇ ment manufacture and, on the other hand, are available at low cost and in large quantities, and the use of which in addition satisfies the environmental requirements one today places on the industry and its waste products.
  • the problem according to the invention was solved by using, as chromium reduction agent, ferrous sulphate originating from the titanium pigment manufacture.
  • ferrous con ⁇ tent in such a ferrous sulphate side product which pri- marily in its monohydrate form, lies typically in the range of from 13 to 18 % by weight and it has a high sul ⁇ phuric acid content, up to 30 % by weight, typically from about 10 to 30 % by weight, and is therefore extremely corroding and useless as such.
  • This product contains in addition a considerable amount of moisture, up to 10 % by weight, and smaller amounts of trace elements. It is a product which is extremely difficult to handle and a bur ⁇ den on the environment, and has to be neutralized in or ⁇ der to be deposited.
  • Such methods according to which the neutralization takes place in an aqueous solution to an alkaline pH have been described, for example, in DE OS 4103311 and 3724677.
  • this moist and sulphuric acid rich ferrous sulphate obtained as a side product is neut ⁇ ralized and dried with a CaO-containing material, prefe ⁇ rably cement, optionally together with limestone, to a pH-value of 1.5 to 5, thereby allowing the reaction tem ⁇ perature to rise to at the most 120 °C.
  • a large part of both the free water and the water bound in crystal water form leaves, and as major products fer ⁇ rous sulphate hydrate, which is water soluble, primarily in the form of monohydrate, and gypsum, calcium sulphate, which is one of the starting materials in cement produc ⁇ tion, are obtained.
  • the temperature does not exceed the said 120 °C in order to ensure that not all hydrate water leaves the product and that the iron is not oxidized to trivalent form which is useless for the chromium reduc ⁇ tion.
  • the product obtained has excellent handling, espe- cially flow characteristics, and it can be pumped and blown in silos, and it does not dust, which is of essen ⁇ tial importance in industry in outdoor handling.
  • a method has been pro- vided according to which a waste product from the ti ⁇ tanium dioxide pigment industry in a simple and economi ⁇ cal manner kan be converted to a product which is easy to handle and which without any problems can be further uti ⁇ lized in full in cement manufacture.
  • the product contains only such components which are already included among the cement manufacture materials and thus does not contribute with any side products whatsoever which are detrimental to the cement manufacture.
  • CaO-containing material cement or a cement containing material, e.g. slag or fly ash cement, optionally toge ⁇ ther with limestone, are used.
  • the CaO-containing mate ⁇ rial is added to the starting ferrous sulphate in subs ⁇ tantially dry form. It is in principle possible to use any type of CaO-containing material, for example steel slag, blast furnace slag, precipitator dust etc. provided they exhibit sufficient hydraulic characteristics.
  • Pro ⁇ ducts having a lower reactivity e.g. filter dust from the cement and lime industry, limestone, and even fly ash, are usable in an initial stage of the process, but in such case a post-treatment with more reactive mate ⁇ rial, e.g. cement, has to be carried out. It is also con- ceivable to use hydrated and unhydrated lime, but the use of these extremely reactive materials require a strict temperature control.
  • the amount of CaO-containing material to be added depends naturally on the sulphuric acid content in the starting material, but an amount of from 5 to 20 % by weight, cal ⁇ culated from the starting ferrous sulphate, is in most cases sufficient to neutralize to the desired pH and to dry the product.
  • the starting ferrous sulphate is used in the form it is obtained from the pigment production, that is in crystallized, filter dry pressed form, which gene ⁇ rally means a moisture content of less than appr. 10 % by weight in the starting product. It is also possible to carry out a careful pre-drying of the starting material.
  • the addition of CaO-containing material leads to an exo ⁇ thermic reaction, which aids in the removal of free mois ⁇ ture from the material.
  • the flow characteristics of the obtained product can be further improved by treating the product with fly ash, either already together with the neutralizing material or after neutralization, using an amount up to 20 % by weight of the ferrous sulphate.
  • Fly ash as such does not possess sufficient hydraulic properties to function alone as both a neutralization and drying medium, but can very well be used as a post-treatment agent, or filler.
  • the neutralizing agent preferably cement, optionally together with limestone
  • the neutralizing agent is added in an amount which gi ⁇ ves a pH of appr. 3 to 4. It is also preferable to keep the temperature below appr. 105 °C, optimally at appr. 80 to 105 °C, whereby a soluble product suitable for passi ⁇ vation, is obtained.
  • the treatment can take place so that in a first stage limestone is added, which, as mentioned above, gives a slower reaction and a lesser temperature increase, for example to a pH of appr. 1.4, and thereafter the more active material, e.g. cement, is added to raise the pH to the desired pH end value. This procedure provides an ex- cellent temperature control.
  • the amount of cement or a material with com ⁇ parative reactivity can be reduced, for example to 2 to 15 % by weight of the starting material.
  • the pH value is measured by dissolving one part by weight of ferrous sul- phate in 9 parts by weight of water.
  • the composition of the product obtained after the treat ⁇ ment varies to some degree depending on the composition of the starting material and the amount and type of neut- ralizing agents used. From the point of view of use, na ⁇ turally the ferrous content, i.e. the Fe 2+ -content, is of importance, and this is generally within the range of 10 to 18 % by weight, which corresponds to a ferrous sulpha ⁇ te content in pure hydrate form of appr. 30 to 55 % by weight.
  • the product typically contains appr. 15 to 30 % by weight of gypsum, CaS0 4 , and moisture, typi ⁇ cally 2 to 5 % by weight, and other products, e.g. cement and limestone.
  • the product is well preserved during ce ⁇ ment manufacture, i.e. there is no premature oxidation to Fe 3+ in the mill, the product does not irritate and it is compatible with the cement manufacture.
  • the gypsum in the product can substitute part of the amount of gypsum nor ⁇ mally used in cement manufacture.
  • the mixing took place in a continuous concrete mixing plant. The mixing time was short, only a few seconds, whereafter the mixture was deposited for end reaction. Mixing took place without any disturbances from the materials used. An analysis of the end material showed that the Fe 2+ -con ⁇ tent was substantially the same and that essentially no oxidation to Fe 3+ had taken place.
  • the pH of the end pro ⁇ duct was 1.5.
  • the ferrous sulphate had been pre-treated with 8 % by weight of limestone. From the results it can be seen i.a. that the temperature can be regulated by means of a suitable choice of cement ty ⁇ pe.
  • the capacity of the ferrous sulphate hydrate products made according to the process namely products 2 and 3 from the Table 3 was measured.
  • One part by weight of products 2 and 3, respectively, was mixed with 92 parts by weight of Rapid cement and 7 parts by weight of gypsum.
  • the content of sixvalent chromium (Cr 6+ ) was measured in the obtained product.
  • the reduction capacity of the product was measured using the standard SFS 5183 (24.3.86) by adding to the mixture an excess of 50 mg/kg Cr 6+ and measuring the amount of re ⁇ quizd chromium. Without the addition of extra chromium no measurable chromium content is obtained. The higher the value, the better reduction capacity of the product
  • n.a. not analyzed.

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  • Chemical & Material Sciences (AREA)
  • Organic Chemistry (AREA)
  • Inorganic Chemistry (AREA)
  • Engineering & Computer Science (AREA)
  • Ceramic Engineering (AREA)
  • Materials Engineering (AREA)
  • Structural Engineering (AREA)
  • Compounds Of Alkaline-Earth Elements, Aluminum Or Rare-Earth Metals (AREA)
  • Inorganic Compounds Of Heavy Metals (AREA)
  • Curing Cements, Concrete, And Artificial Stone (AREA)

Abstract

L'invention se rapporte à un procédé de traitement de sulfate ferreux en vue de la préparation d'hydrate de sulfate ferreux utilisé pour la réduction du chrome dans la fabrication du ciment. Selon l'invention, l'acide sulfurique contenant du sulfate ferreux obtenu comme produit secondaire de la production de dioxyde de titane et qui contient approximativement 30 % en poids d'acid sulfurique, est neutralisé avec une substance contenant du CaO, de préférence du ciment, en quantité suffisante pour donner au produit final un pH compris entre 1,5 et 5, permettant ainsi à la température de réaction d'augmenter jusqu'à 120 °C au maximum.
PCT/FI1996/000198 1995-04-21 1996-04-12 Procede de traitement de sulfate ferreux WO1996033133A1 (fr)

Priority Applications (1)

Application Number Priority Date Filing Date Title
EP96910049A EP0821656A1 (fr) 1995-04-21 1996-04-12 Procede de traitement de sulfate ferreux

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
FI951922 1995-04-21
FI951922A FI100966B (sv) 1995-04-21 1995-04-21 Förfarande för behandling av ferrosulfat

Publications (1)

Publication Number Publication Date
WO1996033133A1 true WO1996033133A1 (fr) 1996-10-24

Family

ID=8543287

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/FI1996/000198 WO1996033133A1 (fr) 1995-04-21 1996-04-12 Procede de traitement de sulfate ferreux

Country Status (3)

Country Link
EP (1) EP0821656A1 (fr)
FI (1) FI100966B (fr)
WO (1) WO1996033133A1 (fr)

Cited By (14)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
FR2761679A1 (fr) * 1997-04-08 1998-10-09 Carrieres Du Boulonnais Procede pour l'elimination d'acides sulfureux residuaires de traitement industriel et pour l'obtention de produits stables
EP1123719A2 (fr) * 2000-01-10 2001-08-16 mg technologies ag Procédé pour le traitement de résidus contenant du chrome (VI)
EP1314706A3 (fr) * 2001-11-21 2004-05-26 Ferro Duo GmbH Liant hydraulique
EP1440954A1 (fr) * 2003-01-25 2004-07-28 Ferro Duo GmbH Liant hydraulique avec une teneur en chromate réduite
WO2005009917A1 (fr) * 2003-07-17 2005-02-03 Kerr-Mcgee Pigments Gmbh Agent de reduction destine aux chromates solubles presents dans du ciment et procedes de production dudit agent de reduction
EP1580175A1 (fr) * 2004-03-23 2005-09-28 Alexander Kehrmann Agrégat pour béton
WO2008000855A1 (fr) * 2006-06-27 2008-01-03 Aditivos Del Cemento, S.L. Procédé d'obtention d'un additif pour le ciment et additif ainsi obtenu
WO2008000887A1 (fr) 2006-06-28 2008-01-03 Sachtleben Pigments Oy Procédé de traitement d'un précipité comprenant du sulfate de fer (ii) monohydraté, une usine, un matériau granulaire et ses applications
EP1892219A1 (fr) * 2006-06-28 2008-02-27 Kemira Pigments Oy Procédé de traitement d'un précipité comprenant du sulfate de fer (II) monohydraté, une installation, matériau granulaire et ses utilisations
US7717999B1 (en) 2008-12-24 2010-05-18 The National Titanium Dioxide, Co., Ltd. (Cristal) Titanium production waste byproduct as partial cement replacement
CN101955233A (zh) * 2010-08-30 2011-01-26 攀枝花圣地元科技有限责任公司 生产一水硫酸亚铁的方法
EP1544182B2 (fr) † 2003-12-12 2016-04-06 Kehrmann Alexander Liant hydraulique
CN113060948A (zh) * 2021-04-01 2021-07-02 重庆康尼睿能商贸有限公司 一种水泥生料及水泥的制备方法
ES2926356A1 (es) * 2021-04-14 2022-10-25 Aditivos Del Cemento S L MEZCLA REDUCTORA DE Cr(VI) CONTENIDO EN CEMENTO A Cr(III)

Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB1581539A (en) * 1976-10-07 1980-12-17 Laporte Industries Ltd Making plaster from ferrous sulphate
WO1984001942A1 (fr) * 1982-11-17 1984-05-24 Aalborg Portland Cement Procedes de production d'un melange de ciment frais et d'un produit d'hydrate de sulfate ferreux s'ecoulant librement ainsi que les produits prepares par ces procedes

Patent Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB1581539A (en) * 1976-10-07 1980-12-17 Laporte Industries Ltd Making plaster from ferrous sulphate
WO1984001942A1 (fr) * 1982-11-17 1984-05-24 Aalborg Portland Cement Procedes de production d'un melange de ciment frais et d'un produit d'hydrate de sulfate ferreux s'ecoulant librement ainsi que les produits prepares par ces procedes

Cited By (24)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
FR2761679A1 (fr) * 1997-04-08 1998-10-09 Carrieres Du Boulonnais Procede pour l'elimination d'acides sulfureux residuaires de traitement industriel et pour l'obtention de produits stables
EP0870738A1 (fr) * 1997-04-08 1998-10-14 Carrières du Boulonnais Procédé pour l'élimination d'acides sulfureux résiduaires de traitement industriel et pour l'obtention de produits stables
US6190449B1 (en) * 1997-04-08 2001-02-20 Carrieres Du Boulonnais Method for eliminating waste sulfurous acids coming from industrial treatments and for obtaining stable products
EP1123719A2 (fr) * 2000-01-10 2001-08-16 mg technologies ag Procédé pour le traitement de résidus contenant du chrome (VI)
EP1123719A3 (fr) * 2000-01-10 2001-09-12 mg technologies ag Procédé pour le traitement de résidus contenant du chrome (VI)
EP1314706A3 (fr) * 2001-11-21 2004-05-26 Ferro Duo GmbH Liant hydraulique
EP1440954A1 (fr) * 2003-01-25 2004-07-28 Ferro Duo GmbH Liant hydraulique avec une teneur en chromate réduite
WO2005009917A1 (fr) * 2003-07-17 2005-02-03 Kerr-Mcgee Pigments Gmbh Agent de reduction destine aux chromates solubles presents dans du ciment et procedes de production dudit agent de reduction
EP1780183A2 (fr) * 2003-07-17 2007-05-02 Tronox Pigments International GmbH Agent de réduction destiné aux chromates solubles présents dans le ciment et procédé de production dudit agent de réduction
EP1780183A3 (fr) * 2003-07-17 2007-07-25 Tronox Pigments International GmbH Agent de réduction destiné aux chromates solubles présents dans le ciment et procédé de production dudit agent de réduction
JP2009500268A (ja) * 2003-07-17 2009-01-08 カー−マックギー・ピグメンツ・ゲーエムベーハー セメントの可溶性クロム酸塩含有物用還元剤およびその製造方法
EP1544182B2 (fr) † 2003-12-12 2016-04-06 Kehrmann Alexander Liant hydraulique
EP1580175A1 (fr) * 2004-03-23 2005-09-28 Alexander Kehrmann Agrégat pour béton
WO2008000855A1 (fr) * 2006-06-27 2008-01-03 Aditivos Del Cemento, S.L. Procédé d'obtention d'un additif pour le ciment et additif ainsi obtenu
WO2008000887A1 (fr) 2006-06-28 2008-01-03 Sachtleben Pigments Oy Procédé de traitement d'un précipité comprenant du sulfate de fer (ii) monohydraté, une usine, un matériau granulaire et ses applications
EP2371769A1 (fr) 2006-06-28 2011-10-05 Sachtleben Pigments Oy Procédé de traitement d'un précipité comportant un monohydrate de sulfate de fer (II), installation, matériau granulaire et ses utilisations
US8128903B2 (en) 2006-06-28 2012-03-06 Sachtleben Pigments Oy Method of treating a precipitate comprising iron (II) sulfate monohydrate, a plant, granular material and its uses
EP1892219A1 (fr) * 2006-06-28 2008-02-27 Kemira Pigments Oy Procédé de traitement d'un précipité comprenant du sulfate de fer (II) monohydraté, une installation, matériau granulaire et ses utilisations
US7717999B1 (en) 2008-12-24 2010-05-18 The National Titanium Dioxide, Co., Ltd. (Cristal) Titanium production waste byproduct as partial cement replacement
US7824322B2 (en) 2008-12-24 2010-11-02 The National Titanium Dioxide, Co. Ltd. (Cristal) Titanium production waste byproduct as partial cement replacement
CN101955233A (zh) * 2010-08-30 2011-01-26 攀枝花圣地元科技有限责任公司 生产一水硫酸亚铁的方法
CN101955233B (zh) * 2010-08-30 2012-07-11 攀枝花圣地元科技有限责任公司 生产一水硫酸亚铁的方法
CN113060948A (zh) * 2021-04-01 2021-07-02 重庆康尼睿能商贸有限公司 一种水泥生料及水泥的制备方法
ES2926356A1 (es) * 2021-04-14 2022-10-25 Aditivos Del Cemento S L MEZCLA REDUCTORA DE Cr(VI) CONTENIDO EN CEMENTO A Cr(III)

Also Published As

Publication number Publication date
EP0821656A1 (fr) 1998-02-04
FI951922A (fi) 1996-10-22
FI951922A0 (fi) 1995-04-21
FI100966B (sv) 1998-03-31

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