ES2251879B1 - HEXAVALENT CHROME REDUCING ADDITIVE PRESENT IN CEMENTING MATRICES. - Google Patents
HEXAVALENT CHROME REDUCING ADDITIVE PRESENT IN CEMENTING MATRICES. Download PDFInfo
- Publication number
- ES2251879B1 ES2251879B1 ES200402566A ES200402566A ES2251879B1 ES 2251879 B1 ES2251879 B1 ES 2251879B1 ES 200402566 A ES200402566 A ES 200402566A ES 200402566 A ES200402566 A ES 200402566A ES 2251879 B1 ES2251879 B1 ES 2251879B1
- Authority
- ES
- Spain
- Prior art keywords
- reducing additive
- hexavalent chromium
- cements
- cement
- chromium
- 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.)
- Expired - Fee Related
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
-
- 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
Abstract
Aditivo reductor de cromo hexavalente presente en matrices cementantes. El objeto de esta invención esta relacionada con la utilización de un aditivo reductor, a base de ditionito o hidrosulfito, como agente reductor del cromo VI soluble en agua contenido en las materias primas, clinkeres y cementos Pordland. Con este aditivo reductor se consigue, con una mínima cantidad, reducir los contenidos de cromo hexavalente presentes en los materiales cementantes por debajo del límite máximo permitido en la normas internacionales (2 ppm). Contenidos de aditivo reductor hasta el 0,3% en peso de cemento, puede incorporarse a la matriz cementante para la obtención cementos denominados como "cementos sin cromo hexavalente".Hexavalent chromium reducing additive present in cementitious matrices. The object of this invention is related to the use of a reducing additive, based on dithionite or hydrosulfite, as a reducing agent for water-soluble chromium VI contained in Pordland raw materials, clinkeres and cements. With this reducing additive it is possible, with a minimum amount, to reduce the hexavalent chromium contents present in the cementitious materials below the maximum limit allowed in international standards (2 ppm). Contents of reducing additive up to 0.3% by weight of cement, can be incorporated into the cementitious matrix to obtain cements called "cements without hexavalent chromium".
Description
Aditivo reductor de cromo hexavalente presente en matrices cementantes.Hexavalent chromium reducing additive present in cementitious matrices.
El sector de la técnica está dirigido principalmente al sector químico, fabricante del aditivo reductor comercial y, en segundo lugar, al sector de los fabricantes de cementos por ser el sector se aplicación de la invención, principalmente.The technical sector is directed mainly to the chemical sector, manufacturer of the reducing additive commercial and, secondly, to the sector of the manufacturers of cements for being the sector application of the invention, mainly.
Se tiene conocimiento de varias patentes en las que se describen diferentes productos químicos para la reducción de cromo VI en cementos:There are several patents in the that different chemicals are described for the reduction of chromium VI in cements:
- \bullet?
- Patente US4572739 (1982) utiliza el sulfato ferroso granulado con película protectora.US4572739 (1982) uses granulated ferrous sulfate with protective film.
- \bullet?
- Patente WO8401942 (1984) utiliza el sulfato Ferroso heptahidratado secado a 20-60ºC y mezclado con arcilla, cemento, etc.WO8401942 (1984) patent uses Ferrous sulfate heptahydrate dried at 20-60 ° C and mixed with clay, cement, etc.
- \bullet?
- Patente JP3205331 (1991) utiliza sulfato ferroso.JP3205331 (1991) uses ferrous sulfate.
- \bullet?
- Patente EP0934914 (1994) utiliza lignosulfonato para este fin.EP0934914 (1994) uses lignosulfonate for this purpose.
- \bullet?
- Patente JP11092193 (1999) utiliza Cloruro de Bario como reductor.JP11092193 (1999) Use Barium Chloride as a reducer.
- \bullet?
- Patente EP092690 (2001) utiliza los carbonatos Férricos tratados térmicamente o mecánicamente.EP092690 (2001) patent uses thermally treated ferric carbonates or mechanically.
- \bullet?
- Patente JP2002060751 (2002) utiliza diferentes quelantes más sulfatos.JP2002060751 (2002) use different chelants plus sulfates.
- \bullet?
- Patente JP2002274907 (2002) utiliza como agente reductor un subproducto de la síntesis del acetileno.JP2002274907 (2002) uses as a reducing agent a byproduct of the synthesis of acetylene.
- \bullet?
- Patente CN 1299788 (2001) emplea una escoria de bario como agente reductor.CN patent 1299788 (2001) employs a barium slag as a reducing agent.
- \bullet?
- Patente WO 8402900 (1984) utiliza el sulfato ferroso en forma de ferroyeso.WO 8402900 (1984) uses ferrous sulfate ferrous sulfate.
El objeto de esta invención esta relacionada con la utilización de un aditivo reductor, a base de hidrosulfito, como agente reductor del cromo VI soluble en agua contenido en las materias primas, componentes utilizados en la fabricación del cemento Portland (clinkeres, adiciones activas, aditivos, etc) y cementos portland.The object of this invention is related to the use of a reducing additive, based on hydrosulfite, as water soluble chromium VI reducing agent contained in the raw materials, components used in the manufacture of Portland cement (clinkeres, active additions, additives, etc.) and Portland Cements
El sector de la construcción y, más concretamente la industria cementera es uno de los principales motores de la economía mundial. De acuerdo con los datos disponibles, la producción mundial de cemento está en torno a 1.736,9 millones de toneladas en el año 2002, de los cuales 40 m.tn corresponde a la producción española.The construction sector and, more specifically the cement industry is one of the main engines of the world economy. According to the data available, global cement production is around 1,736.9 million tons in 2002, of which 40 m.tn corresponds to the Spanish production.
Los clinkeres y cementos Pórtland comerciales
principalmente contienen elementos minoritarios en su composición
química, cuya presencia tiene una incidencia directa en aspectos
científicos, técnicos y medioambiental. Sin embargo, algunos de
ellos, principalmente cromo VI soluble en agua, tiene un efecto
negativo en la salud humana (alérgenos), constituyendo el principal
causante de la Dermatitis Profesional (irritante y alérgica) e
incluso el cromo VI es
cancerígeno por inhalación.Commercial Portland cement and cement mainly contain minor elements in their chemical composition, whose presence has a direct impact on scientific, technical and environmental aspects. However, some of them, mainly water soluble chromium VI, have a negative effect on human health (allergens), constituting the main cause of Professional Dermatitis (irritant and allergic) and even chromium VI is
carcinogen by inhalation.
Debido a las consecuencias toxicológicas, la Directiva 76/769/CEE (2003) recoge la limitación de la comercialización y el uso de determinadas sustancias y preparados peligrosos, señalando que ``el cemento y los preparados que contiene cemento no se pueden usar o poner en el mercado si, su contenido de cromo VI soluble es superior a 2 ppm. De acuerdo con la experiencia del grupo investigador la mayoría de los cementos comerciales (nacionales y de importación) superan este valor.Due to the toxicological consequences, the Directive 76/769 / EEC (2003) includes the limitation of the marketing and use of certain substances and preparations dangerous, noting that `` the cement and the preparations that contains cement cannot be used or placed on the market if, its Soluble chromium VI content is greater than 2 ppm. In accordance with the experience of the research group most cements Commercial (domestic and import) exceed this value.
Para poder cumplir esta limitación es necesario disponer de agentes reductores que tengan capacidad de reducir el cromo VI soluble en agua a cromo III insoluble, sin alterar las propiedades de la matrices cementantes. Por lo tanto, urge la necesidad de buscar nuevos agentes reductores que permitan reducir al máximo los problemas de salud y facilitar al sector cementero alternativas reales y eficaces para controlar su contenido.In order to comply with this limitation it is necessary have reducing agents that have the capacity to reduce the water soluble chromium VI to insoluble chromium III, without altering the properties of cementitious matrices. Therefore, the need to look for new reducing agents that allow reducing maximizing health problems and facilitating the cement sector Real and effective alternatives to control its content.
La Directiva 76/769/CEE, basándose en el informe del Comité Científico sobre Toxicidad, Ecotoxicidad y Medioambiente (CSTEE), solicitado por la Comisión Europea de Salud y Protección al consumidor argumenta las ventajas de utilización del sulfato ferroso como reductor del Cromo VI en los cementos, el cual está basado en la experiencia danesa (seguida de Findandia, Suecia y Alemania), cuya legislación contempla la reducción del cromo VI en los cementos con sulfato ferroso.Directive 76/769 / EEC, based on the report of the Scientific Committee on Toxicity, Ecotoxicity and Environment (CSTEE), requested by the European Health and Protection Commission the consumer argues the advantages of sulfate utilization ferrous as a reducer of Chromium VI in cements, which is based on the Danish experience (followed by Findandia, Sweden and Germany), whose legislation contemplates the reduction of chromium VI in Cements with ferrous sulfate.
La disponibilidad y normalización sólo de un agente reductor a nivel mundial y, concretamente en España, solo existe una empresa que comercializa un reductor como un subproducto industrial en forma de sulfato ferroso heptahidratado húmedo, el cual tiene asociada diferentes inconvenientes relacionados con aspectos técnicos y económicos principalmente; tales como disponibilidad de ese producto, estabilidad del mismo (la cual disminuye con la temperatura), eficacia o caducidad (de acuerdo con la experiencia europea se necesita un mínimo de 0.35% de SO_{4}Fe 7H_{2}O, para mantener el contenido de cromo por debajo de 2 mg/Kg, problemas de homogeneización en el momento del mezclado con el cemento, disponibilidad de medios técnicos adicionales para su almacenamiento y mezclado, etc las cuales pueden encarecer el precio del cemento final.The availability and standardization of only one reducing agent worldwide and, specifically in Spain, only there is a company that markets a reducer as a byproduct industrial in the form of ferrous sulfate heptahydrate moist, the which has associated different inconveniences related to technical and economic aspects mainly; such as availability of that product, its stability (which decreases with temperature), efficacy or expiration (according to European experience requires a minimum of 0.35% of SO_ {4} Fe 7H 2 O, to keep the chromium content below 2 mg / kg, homogenization problems at the time of mixing with cement, availability of additional technical means for its storage and mixing, etc. which can make the final cement price.
Por este motivo, en los últimos años existe investigaciones encaminadas a conocer y profundizar en esta línea de investigación (ver patentes). En este sentido, la presente invención propone utilizar el agente reductos a base de Hidrosulfito como nuevo agente reductor químico del cromo VI en clinkeres, cementos y sus derivados. Este reductor es un producto comercial, que por su características es fácil de conseguir, manejar y presenta un alto valor negativo del potencial oxidación-reducción E = -1,12 V en medio básico, lo que implica que este producto es un agente reductor potente del cromo VI en matrices cementantes, las cuales se caracterizan por presentar valores de pH superiores a 12-12,5.For this reason, in recent years there is research aimed at knowing and deepening in this line of research (see patents). In this sense, the present invention proposes to use the reductive agent based on Hydrosulfite as a new chemical reducing agent for chromium VI in clinkeres, cements and their derivatives. This reducer is a product commercial, which by its characteristics is easy to obtain, handle and has a high negative value of the potential oxidation-reduction E = -1,12 V in basic medium, what which implies that this product is a potent reducing agent of chromium VI in cementitious matrices, which are characterized by have pH values greater than 12-12.5.
La descripción de la invención se basa en
mezclar con los medios disponibles una cantidad determinada de
matriz cementante con un porcentaje de reductor hasta el 0,3% de
peso de cemento, hasta la obtención de una mezcla homogénea de
cemento-agente reductor que, a nivel de laboratorio
es suficiente con 15 min de tiempo de mezclado. Una vez obtenida la
mezcla homogénea se almacena en un recipiente adecuado a ambiente
de laboratorio hasta la realización de los ensayos de lixiviación
de cromo soluble en agua, de acuerdo con la metodología recogida
en
norma.The description of the invention is based on mixing with the available means a certain amount of cementitious matrix with a percentage of reducer up to 0.3% of cement weight, until a homogeneous mixture of cement-reducing agent is obtained which, at Laboratory level is sufficient with 15 min of mixing time. Once the homogeneous mixture has been obtained, it is stored in a suitable container in a laboratory environment until the water soluble chromium leaching tests are carried out, in accordance with the methodology included in
rule.
Los resultados analíticos realizados en el laboratorio se basaron en la incorporación de diferentes porcentajes de agente reductor a base de hidrosulfito (hasta un 0.3% en peso de cemento) a dos cementos comerciales con diferentes contenidos de cromo soluble en agua (aprox 4 y 6,5 ppm), poniendo de manifiesto que la adición de este reductor (hasta un 0,3% en peso de cemento) actúa como un agente reductor muy fuerte de cromo VI presente en los cementos comerciales y, destacando que la incorporación mínima de 0,1% de agente reductor a la matriz cementante es suficiente para reducir el contenido de cromo VI soluble en agua por debajo de 0,1 ppm durante un periodo mínimo de 6 meses. Valores muy inferiores al valor máximo permitido en norma (2 ppm), de cumplimiento obligatorio para todos los Estados Miembros de la Comunidad Económica Europea.The analytical results performed in the laboratory were based on the incorporation of different percentages of hydrosulfite-based reducing agent (up to 0.3% by weight of cement) to two commercial cements with different water soluble chromium contents (approx. 4 and 6.5 ppm), setting It is clear that the addition of this reducer (up to 0.3% by weight cement) acts as a very strong reducing agent of chromium VI present in commercial cements and, highlighting that the minimum incorporation of 0.1% of reducing agent to the matrix Cementing agent is sufficient to reduce chromium VI content Water soluble below 0.1 ppm for a minimum period of 6 months. Values far below the maximum value allowed in the standard (2 ppm), mandatory for all States Members of the European Economic Community.
Con el objeto de esta invención, se consigue, disponer de una nueva gama de agentes reductores a los ya existentes en el mercado, con el objetivo de: 1. resolver el problema social que existe en la actualidad sobre la influencia del cromo VI de los cementos en la salud humana, 2. mejorar los problemas técnicos del sulfato ferroso heptahidratado húmedo, único agente reductor comercializado en España y, 3. dar a conocer a los fabricantes de cementos y sus derivados alternativas viables de nuevos agentes reductores más eficaces técnicamente que el agente reductor normalizado en la actualidad.For the purpose of this invention, it is achieved, have a new range of reducing agents to those already existing in the market, with the aim of: 1. resolving the social problem that currently exists on the influence of chromium VI of cements in human health, 2. improve technical problems of ferrous sulfate heptahydrate moist, unique reducing agent marketed in Spain and, 3. publicize cement manufacturers and their viable alternative derivatives of new reducing agents more technically effective than the agent standardized reducer today.
La realización de la invención es fácil de llevar a cabo, ya que no se necesita ninguna instalación o metodología específica a la ya existente tanto a nivel de laboratorio como industrial. En este último caso la incorporación se llevaría a cabo tanto en la molienda conjunta clinker-regulador de fraguado como en un mezclado previo con el cemento Pórtland antes del almacenamiento.The embodiment of the invention is easy to carry out, since no installation is needed or specific methodology to the existing one both at the level of Laboratory as industrial. In the latter case the incorporation is would carry out both in the joint milling clinker-setting regulator as in a mixed prior to Portland cement before storage.
El ejemplo de realización a nivel de laboratorio sería de la siguiente forma:The example of realization at the laboratory level It would be as follows:
Se toma una cantidad determinada de cemento comercial o material a ensayar (p.e. 100 gr), previamente secado en una estufa de desecación a 105ºC, y se deposita en un recipiente de cristal o plástico con capacidad suficiente.A certain amount of cement is taken commercial or material to be tested (e.g. 100 gr), previously dried in a drying oven at 105 ° C, and is deposited in a container of glass or plastic with sufficient capacity.
A continuación, se toman 0,1% de ditionito comercial con relación al peso de cemento seleccionado anteriormente (0.1 gr/100 gr de cemento) y se deposita en el recipiente anterior. Una vez introducidos los dos materiales, se homogeniza mediante un dispositivo mecánico usado para este fin durante 15 minutos.Next, 0.1% dithionite is taken commercial in relation to the selected cement weight previously (0.1 gr / 100 gr of cement) and deposited in the anterior vessel Once the two materials have been introduced, homogenize by means of a mechanical device used for this purpose during 15 minutes.
Una vez obtenida la mezcla homogénea, se almacena en un recipiente adecuado a ambiente de laboratorio, hasta la realización de los ensayos de lixiviación de cromo soluble en agua y su posterior cuantificación de acuerdo con la metodología recogida en las normas existentes.Once the homogeneous mixture is obtained, it is Store in a container suitable for laboratory environment, up to the performance of soluble chromium leaching tests in water and its subsequent quantification according to the methodology Collection in existing standards.
Los resultados analíticos de cromo soluble en los clinkeres y cementos Pórtland, en los que previamente se les había incorporado este reductor, presentaban concentraciones mínimas (inferiores al 0,1 ppm) lo que supone una reducción de 65 veces el contenido de cromo original (para un cemento de 6,5 ppm de cromo VI).The analytical results of soluble chromium in portland clinkeres and cements, in which they were previously had incorporated this reducer, presented concentrations minimum (less than 0.1 ppm) which means a reduction of 65 times the original chromium content (for a 6.5 ppm cement of chrome VI).
Claims (4)
cementos, derivados y adiciones puzolánicas.2. Hexavalent chromium reducing additive of the family of sulfur derivatives according to claim 1 characterized by incorporating up to 0.3% by weight of sample of dithionite or sodium hydrosulfite under normal conditions to clinkeres,
Cements, derivatives and pozzolanic additions.
Priority Applications (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| ES200402566A ES2251879B1 (en) | 2004-10-26 | 2004-10-26 | HEXAVALENT CHROME REDUCING ADDITIVE PRESENT IN CEMENTING MATRICES. |
| PCT/ES2005/070149 WO2006048488A1 (en) | 2004-10-26 | 2005-10-25 | Additive for reducing hexavalent chromium present in binding matrices |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| ES200402566A ES2251879B1 (en) | 2004-10-26 | 2004-10-26 | HEXAVALENT CHROME REDUCING ADDITIVE PRESENT IN CEMENTING MATRICES. |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| ES2251879A1 ES2251879A1 (en) | 2006-05-01 |
| ES2251879B1 true ES2251879B1 (en) | 2007-07-01 |
Family
ID=36318917
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| ES200402566A Expired - Fee Related ES2251879B1 (en) | 2004-10-26 | 2004-10-26 | HEXAVALENT CHROME REDUCING ADDITIVE PRESENT IN CEMENTING MATRICES. |
Country Status (2)
| Country | Link |
|---|---|
| ES (1) | ES2251879B1 (en) |
| WO (1) | WO2006048488A1 (en) |
Family Cites Families (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US6991593B2 (en) * | 2001-12-05 | 2006-01-31 | Heritage Environmental Services, Llc | Hazardous waste stabilization methods, products and testing procedures |
| DE602004004870D1 (en) * | 2004-03-23 | 2007-04-05 | Gruppo Chimico Dalton S P A | Process for producing chromate-reduced cement |
-
2004
- 2004-10-26 ES ES200402566A patent/ES2251879B1/en not_active Expired - Fee Related
-
2005
- 2005-10-25 WO PCT/ES2005/070149 patent/WO2006048488A1/en active Application Filing
Non-Patent Citations (1)
| Title |
|---|
| LASKOWSKY,C. IRON(II)-SULFATE AS CONCRETE ADMIXTURE FOR CHROMIUM(VI) REDUCTION. Otto Graf Journal, Volumen 7 (1996), páginas 69-82. * |
Also Published As
| Publication number | Publication date |
|---|---|
| WO2006048488A1 (en) | 2006-05-11 |
| ES2251879A1 (en) | 2006-05-01 |
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