BOL. SOC. ESP. CERAM. VIDR. 31 (1992), 5, 419-525

Influence of different carbonaceous binders on the properties of refractories

Prof. Dr. Ing. W. SCHULLE and Dor. Dr. Ing. habil. J. ULBRICHT Institut für Silikattechnik Bergakademie Freiberg/Sachsen

ABSTRACT. Influence of different carbonaceous bin­ders on the properties of refractories.

The influence of différente carbonaceous binders on the properties of MgO-C refractories were reviewed. The utilization of both pitch and zynthetic resin was also discussed, not only in the expansion process, produced during the heat treatment, but also in the material final porosity.

The different behaviour of both binders concerning to the residual carbon content, the oxidation resistance, and the coarsening pores were also reported and exa­mined.

KEY WORDS. rosity, oxidation.

Binders, refractories pitch, resin, po-

RESUMEN. Influencia de los diferentes sistemas aglo­merantes sobre las propiedades de los refractarios.

Se revisan los sistemas de aglomeración empleados en los refractarios de MgO-C, discutiendo las ventajas al­ternativas de utilizar alquitranes o resinas sintéticas, tanto en los procesos de expansión que se produce du­rante el tratamiento térmico como en el volumen y porosidad final del material. Los autores plantean que la mejora de las propiedades de los materiales aglomerados con alquitranes o con resinas es función del contenido en carbón residual, de su comportamiento a la oxidación y el tamaño medio de poro.

PALABRAS CLAVE. Aglomerados, refractarios, al­quitrán, resinas, porosidad, oxidación.

1. INTRODUCTION

The use of carbonaceous refractories has greatly in­creased in recent years (1,2). Table I gives the various pos­sibilities to include carbon in a refractory material. These techniques allow to establish different carbon contents, different types of binding based on a coke skeleton and, thus.

TABLE I

POSSIBILITY FOR ADDITION CARBON TO REFRACTORIES

1. Ipregnation with pitch

app. porosity - 1 5 vol.-% -^ impregnations 2 - 3 m-% coke

2. Bonding with pitch or resin

-1 m-% bonding material with ca. 50 % C-content-^ -3 ,5 m-% coke + 2 - 3 m-% soot -^ 5 - 6-m% coke

3. Addition from solid C-components (graphit, soot) alone or with pitch-/resin bonding or pitch - impregnation 9 -addition -> 12 - 30 m-% C-content

27-m% graphit

different properties; thist last effect is the most interesting. Generally, refractories with an increased content of carbon cannot be strengthened by sintering alone as usual with other types of bricks. Strengthening will have to be achieved mainly by a carbonaceous binder phase which is specially added. The used binders and the type of binding thus produced in the structure are of decisive importance for the properties of the resulting carbonaceous refractories.

The Institute of Silicate Technology has done extensive fundamental research in the field of carbonaceous binders and their influence. This article is to briefly describe some of our results.

Recibido junio de 1992 y aceptado agosto 1992.

2. GENERAL ASSESSMENT OF PITCH BINDING

If a pitch binder is used, heating will first lead to the softening of the binding agent (3). Concurrently, a distilla­tion process begins leading to the release of low-molecular components. At a temperature higher than about 350 °C, liquid crystals form in the isotropic molten phase, which grow under the impact of the continued release of volatile aromatics and the separation of hydrocarbon radicals and eventually are transformed into a soHd phase at about 500 °C. In the further course of pyrolysis, radicals continue to be separated and released by the components of this "green" coke. The process is accompanied by crystal growth and an increase of density in the coke phase. After pyrolysis having come to an end between 900 and 1.000 °C, the material has an anisotropic coke skeleton similar to that of graphite.

Usually, tar pitches with a softening point of 70...80 °C and no less than 42 % coking residue are used as binding agents (4). They are processed at a temperature of 120...150 °C which guarantees a viscosity of 1...4 Pas. In many cases, the moulding process is followed by tempering at 300...450 °C, with the aim of eUminating part of the volatile components. Such treatment provides for a reduced susceptibility to deformation due to an increased viscosity of the binding phase; furthermore, some fraction of the irreversible thermal expansion caused by gas bubbles is accelerated.

The above problems occurring in the application of tar pitch can mostly be avoided by modifying the process. Thus, we have found that the pitch binding can be improved by small additions of sulphur. Figure la shows the change of the weight losses of a pitch binder in dependence on the S addition. The weight losses are reduced (from 56 % to 42 %) and distributed over a larger range of temperatures, as is particularly well shown by figure lb. Due to the dehydrating and vulcanizing effect of the sulphur (5), the compressive strength of sulphur-containing MgO-C bricks (0.5 % S) after

SEPTIEMBRE-OCTUBRE, 1992 419

W. SCHULLER, J. ULBRICHT

200 300 hOO 500 600

TEMPERATURE IN 'C

Fig. la. Mass loss from pitch-sulphur-mixtures in dependency of temperature.

coking increased by 2.5 times, while the open porosity was reduced by 3 %. A greater fraction of coking residue (microcrystalline or amorphous binder coke) was observed in the structure.

3. GENERAL ASSESSMENT OF RESIN BINDING

Artificial resins allow to carry out both moulding and mixing at room temperature. Unlike pitches, they do not proceed through a thermoplastic phase during coking, which creates the possibihty of greater accuracy of the products (6). The decisive factor in the selection of the optimum artificial resin is the residual carbon content after coking. These contents vary over a wide range. Most favorable are the hardenable artifical resins of the phenol formaldehyde type (molecular weight 500...2.000 before hardening), since in their hardened state they form a spatial network which is converted into a complete carbon network (glass carbon) after coking.

The curve of weight losses of a resin binder during heating differs from that of a pitch binder (Figures 2a and 2b). Unlike pitch, phenol formaldehyde resin binders shows a thermosetting behavior. At a temperature normally lying

100 200 300 UOO 500 600

TEMPERATURE IN 'C

Fig. lb. Speed of mass loss from pitch-sulphur-mixtures in dependency of temperature.

100 200 300 kOO 500 600

TEMPERATURE IN "C

Fig. 2a. Mass loss from different bonding-material independency of temperature.

420 BOL. SOC. ESP. CERAM. VIDR. VOL. 31 - NUM. 5

Influence of different carbonaceous binders on the properties of refractories

0,3

1 - PITCH 1

2 - PITCH 2

3 - PITCH 3

4- RESIN

CO m a

tn CO <z

u_ o

ce

200 300 400 500 TEMPERATURE IN "C

600

Fig. 2b. Speed of mass loss form different bonding-material in dependency of temperature.

between 150 and 200 °C the resins harden either directly or catalytically. A high-molecular phenol structure mainly cross-linked by methylene bridges is formed, which is called the resite skeleton. The pyrolysis of resite begins above 350 ''C with the separation of phenols, cresols, xylenols and lower oligomers form the boundary zones of the macro-molecules, as well as the release of hydroxyl groups. Later

on, small amounts of aromatic cores which do not contain hydroxyl groups are separated above 550 °C. Simultaneous­ly, methane and carbon monoxide are produced by the breaking up the phenol cores and from the remaining methyl groups. In the result of pyrolysis, a polymeric carbon skeleton with a spatially interlinked band structure is formed, which can be characterized as widely isotropic. For structural reasons, the coking residue of resin binders is always lower than that of high-quality pitches. Under ideal pyrolysis conditions, about 52 % polymeric carbon can be obtained from the resin binder (solids content 75 %).

4. COMPARATIVE ANALYSIS OF PITCHBOUND AND RESIN-BOUND MqO-C MODEL BATCHES

The model batches used in the investigations can be subdivided into three series:

Series 1 - pitch binder: 5 parts graphite added Series 2 - resin binder: 5 parts graphite added Series 3 - resin binder: 15 parts graphite added

These series each consisted of three batches containing sintered or cast magnesium oxide or a mixture for both (cast magnesium oxide as fine and middle grain), respectively. An overview is given in table IL The type of the used MgO grain and the content of graphite influence the structure of the MgO-C model samples. Some of these influences shall be briefly discussed int his place (7).

The smooth surface of cast MgO leads to poor adhesion of the binder. In fig. 3 (bottom), a smooth coke surface can be observed from which a molten grain has broked free. Moreover, a good cleavability in the coarse grain range is noticed with the cast MgO samples. Large grains of cast magnesium oxide were partially destroyed when the samples were pressed (fig. 4). The increased graphite content of Series 3 leads to a continuous graphite skeleton in the structure of the refractory body (see figs. 5 and 6; 5 % and 15 % graphite, respectively). The coarse fraction is almost

TABLE II

MODEL COMPOSITIONS

Composition

Data in parts

Composition dead burned MgO fused MgO graphite pitch

Resin Composition dead burned MgO fused MgO graphite pitch

liquid soHd

1 a 95 — 5 7 — —

l b 65 30 5 7 — —

I c — 95 5 7 — —

2 a 95 — 5 — 6

2 b 65 30 5 — 6

2 c __ 95 5 — 6

3 a 85 — 15 — 6

3 b 55 30 15 — 6

3c — 85 15 — 6

SEPTIEMBό-OCTUBRE, 1992 421

W. SCHULLER, J. ULBRICHT

Fig. 3. Detail microstrukture composition with pitch bonding (5 % - graphit) coked (SEM).

Fig. 4. Detail microstructure composition with pitch bonding (5 % - graphit) coked (reflected light).

Fig. 5. Detail microstructure composition with resin bonding (5 % - graphit) coked (reflected light).

completely surrounded by graphite flakes in Series 3. To press-induced strains these flakes react by marked deforma­tions (fig. 7).

With respect to the effect of the selected type of binding, it can be said that the expansion-shrinkage behavior of the samples (table HI) is in close connection with the structure of the carbon lattice. Due to the thermoplastic properties of the binder, a liquid phase is formed in pitch-bond samples during the tempering process, leading to the relaxation of pressing strains and an expansion of the samples. In the same way, the vapors produced in the process of distillation contribute to the expansion. As a result of the higher density of pyrolitically formed carbon in comparison with pitch, a slight shrinkage was stated during coking. In Series 2, the fast irreversible hardening of the resin binder hindered the back expansion. The samples of Series 3 with their higher percentage of graphite proved capable of compensating for pressing strains by a deformation of graphite flakes, and also converted into deformations the contraction forces which

TABLE III

EXPANSION-SHRINKEsTG BEHAVIOR

Composition

longitudinal change in %

Composition after tempering, resp. hardening after coking Composition

a b a b

l a +1,13 +0,83 +0,94 +0,69

l b +1,08 +0,88 +,081 +0,68

i c +1,12 +0,89 +1,05 +0,93

2a notdet. notdet. -0,87 -0,66

2b +0,67 +0,39 -0,74 -0,65

2c +0,50 +0,10 -0,82 -0,51

3a -0,27 -0,30 -0,70 -0,43

3b -0,47 -0,33 -0,79 -0,35

3c -0,31 -0,13 -0,61 -0,36

a-in pressing direction referring to green state. b-vertical to pressing direction referring to green state.

422 BOL. SOC. ESP. CEÍIAM. VIDR. VOL. 31 - NUM. 5

Influence of different carbonaceous binders on the properties of refractories

^ ^ ' ^ • ^

Fig. 6. Detail microstructure composition with resin bonding (15 % - graphit) coked (reflected light) - sample 1.

Fig. 7. Detail microstructure composition with resin bonding (15 % - graphit) coked (reflected light) - sample 2.

occurred due to resin shrinkage during hardening; thus, the final result was a shrinkage of these samples. The density increase of resin in the pyrolysis led to further shrinkage of all resin bond samples. The pore structure of the pitch-bond samples was always coarser than that of the resin-bond samples, both in tempered and coked state. This is proved for batches la, 2a and 3a by the pore size distribution function and related distribution densities (figs. 8 to 10).

In the oxidation experiments, it was found that the carbon burnout of the resin-bond batches is in significant relation­ship only with the related residual carbon content, both in hardened and in coked state. With increasing residual carbon content, the relative loss of carbon decreases linearly; the absolute loss of carbon was greater, with the increasing weight loss being governed by a root function (see figs. 11 and 12). For comparison, the losses of pitch-bond batches are shown; a better resistance to combustion particularly after coking is evident. This is explained by the smaller specific inner suface of pitch-bond samples, which was between 0.5 and 1.0 m /̂cm^ both after tempering and after coking. The specific inner surface of resin, bonded samples, in contrast, was measured between 2 and 4 m^/cm^.

In addition, the coke skeleton formed from pitch is less reactive than the polymeric carbon skeleton formed from the

con,pos,-.,on,.n

^ \V(

yJllI Y\\ c _ . . . - ' |

A lil-^^' 1 ^ / J4ÍIII nil 1 / f^

A 1 1 ,^ 4i| ; ̂ • 1 J Ui^

^ •'fi" HI /• ' " — 1 ^ ^ "H" W

\\\^ y \Y

v\ •'' TCTil L- ^1 JAK À\ TT ^

1 ->•-' ' " i l \\\ ^ ̂ r r am " In pore diameter in r

Fig. 8. Pore size distribution ßnctions of compositions 1 a, 2 a and 3 a (tempered, resp. hardened).

H\i 11 NIK NI

/ N ||/f Ir' Ml / \ NI lil-A^ y . . 11 S- — • - > > h i | ---ivri 1 / H / t i r Il ^u Á- 1 1 írU ^ composition 1 . |

:>.^ J/| A |\I 1 Wir /' "̂-̂ J. 4-1 'Hpv composition J I |

^4H -m r i " composition > ' ' |

0 100 10.000 I n p ore d la meter in n

Fig. 9. Pore size distribution density of compositions 1 a, 2 a and 3 a (tempered, resp. hardened).

/ ^ /

m ^ i \m \ Mil \ /III \

/^•\ \ 1 m ^ \ / \ l l : m̂̂ ^̂ \ \

,̂ •xl i 1 / hh/ • ^ • ^ \ 11 / K nil /.-• 1 \ N 1 lir>.

1 ."-{^ A i-Hj; ' '7 \ \ N^ ^ composition 1 . . .

\ 1 i ^n> [/' u\ Ml1 1 11 j . s position a ,

W\\y N-LL 'f r ' " composition 3a

/ / Y_

In pore diameter

Fig. 10. Pore size distribution density of compositions 1 a, 2 a and 3 a (coked).

dm/CR i(

Q series 1, tempered • series 1, coked A series 2, hardened ik series 2, coked Q secies 3, hardened « series 3, coked

Am/CR - 110-3.2 CR (%)

-J ' ' J ' ' '

redisual carbon content

Fig. 11. Mass loss in dependency on residual carbon content, related to residual carbon content (oxidation test 850 °C, 2 hrs. air 60 lit/hr).

SEPTIEMBRE-OCTUBRE, 1992 423

W. SCHULLER, J. ULBRICHT

TABLE IV

VALUES OF COLD CRUSHING STRENGTHS

15 CR in %

r e d i s u a l carbon con ten t

Fig. 12. Mass loss in dependency on residual carbon content, related to mass of sample (oxidation test 850 °C, 2 hrs, air 60 lit/hr).

resin binder for structural reasons. The cold compressive strength of pitch-bonded magnesium oxide - carbon bricks has its minimum after tempering in the melting range of the binder and increases above 500 °C as a result of the forma­tion of the coke lattice. In contrast, resin-bonded MgO-C bricks have their maximum cold compressive strength after hardening which is then reduced in the pyrolysis. Therefore, pitch binders normally guarantee higher strength after coking than do artificial resins. The cold compressive strengths measured for the model samples confirm these statements (table IV).

In conclusion, it can be stated that:

— the expansion-shrinkage behavior of the pitch-bond and resin-bond samples is characterized by considerable dif­ferences. While pitch-bond samples are subjet to expan­sion after tempering or coking in all cases, resinbound samples show more or less pronounced shrinkage phenomena in dependence on their graphite content.

— pitch-bond magnesium oxide - carbon samples differed from resin-bond ones by a higher percentage of coarse pores. The resulting reduced inner surface as well as the anisotropic character of the pyrolytic coke skeleton are the reason for their better resistance to oxidation.

nitrogen air

Flexural strength in MPa

201

Content of Phases in %

—Flexural strength — S i C content .- SÍ2UN2 content «. SiC + SÍ2ON2 content

12

950 1000 1050 1100 llSO 1200 1250 1300 1350 lAOO 1450 1500

Composition cold crushing strength in MPa

Composition green tempered/hardened coked

l a 63,8 35,0 44,2

l b 61,2 32,3 37,2

I c 53,6 28,8 25,7

2 a notdet. 78,9 37,7

2 b notdet. 75,4 34,9

2 c notdet. 71,4 29,2

3a notdet. 49,5 26,3

3 b notdet. 44,1 24,6

3c notdet. 41,6 22,3

— A usual type of pitch binder leads to a higher residual carbon content than do artificial resins. Among others, this leads to a higher strength of the coked pitch-bond samples after pyrolysis.

5. SPECIAL CONSIDERATIONS ON THE BINDING OF MODEL SAMPLES ON THE BASIS OF CORUNDUM-GRAPHITE-RESIN

Within the framework of these investigations, binding was effected with phenol resins of the resol type (7 M%). An addition of about 9 M% of FeSi 90 led to a considerable improvement of the properties in terms of strength and thermal shock resistivity (8). The increased strength is ex­plained by the formation of secondary phases such as SiC and SÍ2ON2 (fig. 13).

argon a i r

JFlexural strength in MPa 1 *-

Content of Phases in % 1

20

15

10

5J

n 1

•Flexural strength I SiC content j

. - i " - - . ^ Î 1 ! f ! ! ! / ! • - .

1

112

9

6

3

0

20

15

10

5J

n 1

' 1 1 : i i I .- I

l i t ! ! / 1 I ! ! f I ' 1 1 1 1 1 .i 1 1 1 ! ! .«'I î

"**«H, 1

112

9

6

3

0

20

15

10

5J

n 1

^^0Ír 1 s' 1 i ¡

l--"^: ! ! ! !

112

9

6

3

0

20

15

10

5J

n 1 1

Î

• ^ " ' ! 1 1 t ! 1 I 1 1 f I 1 l i l i l í

! i 1 1 ! 1 ! 1 1 ! I :

i i

1 1

112

9

6

3

0

9 50 1000 1050 1100 1150 1200 1250 1300 135 3 1400 1450 150t ) 1

Fig. 13. Flexural strength and content of new phases in dependency on temperature for burning in nitrogen-air (left) and argon-air (rigth).

424 BOL. SOC. ESP. CERAM. VIDR. VOL. 31 - NUM. 5

Influence of different carbonaceous binders on the properties of refractories

Fig. 14. Detail microstructur composition free form FeSi-additiori after burning by 1.300 °C.

Fig. 16. Detail microstructur composition with FeSi-addition after burning by 1.300 °C (sample 2%

Fig. 15. Detail microstructur composition with FeSi-addition after burning by 1.300 °C (sample 1).

From about 1.000 °C (the beginning of the strength in­crease), the formation of silicon carbide was detected. In the case of a fumace atmosphere containing nitrogen, the formation of new phases is extended by that of silicon oxinitride above 1.200 °C. In spite of its thermodynamic possibility, no forma­tion of silicon nitride was observed. Silicon carbide formation greatly depends on the fumace atmosphere: it is more pronounced under argon than under nitrogen.

SEM investigations give rise to the supposition that the strengthening effect of the new phases is related to their fibrous shape. A comparison of silicon-containing and silicon-free batches for the former revealed a felt-like matrix into which the grains are embedded (Figs. 14 to 16). This also well explains the improved thermal shock resistivity.

6. REFERENCES

1. MOCHIDA, I.: The Role of Carbon of Refractory Com­posites in the Improvement of their Properties. Taika-butsu, 39 (1987), 2, 108-117.

2. ZEDNICEK, W.: Kohlenstoffhaltige basische feuerfeste Steine - eine neue Generation in der Qualitätspalette der Feuerfestindustrie. Silikattechnik 39 (1988), 11, 385-390.

3. HUTTINGER, K. J.: Die intermidiären Kristallin-flüssi­gen Phasen beim thermischen Abbau von Aromatenge-mischen für graphitischen Kohlenstoff. Ber. OKG 48 (1971), 5, 216-221.

4. BORN, M.; OLSCHINKA, P.: Eigenschaften und Pyroly­severhalten von Pech-bindemitteln für die Herstellung kohlenstoffhaltiger Feuerfestmaterialien. Silikattechnik 40 (1989), 12, 400-403.

5. BACH, U.; ULBRICHT, J.: Beeinflussung ber Pyrolyse­verhalten von Binde-pechen für Feuerfestmaterialien durch Schwefelzusätze. Silikattechnik 39 (1988), 11, 369-374.

6. SRIDHARAN, P.; BAJAN, S.: Phenol Formaldehyde Re­sins for Bonding of Magnesium-Carbon Refractories. Refract J. 62 (1987), 6, 10-11.

7. KLOß, G.; SCHULLE, W.; ZEDNICEK, W.: Beitrag zur Ge-füge-Eigenschafts-Bewertung unterschiedlicher koh­lenstoffhaltiger MgO-Modellversätze. Radex-Rulids-chau 1991, 1/2, 419-432.

8. JUST, T.: Phasenausbildung und Eigenschaftsentwick­lung bei feuerfesten Korund-Graphit-Materialien. Dis­sertation an der Bergakademie Freiberg 1991.

SEPTIEMBRE-OCTUBRE, 1992 425

Precio: Socios SECV 4.000. No socios: 5.000

Capítulo I Características especiales de los sistemas vitreos aplicables a la producción de nuevos esmaltes cerámicos. J. Ma. Rincón 13

Capítulo II Nuevos procesos en la fabricación de pigmentos cerámicos. G. Monrós. J. Cania, M. A. Tena. P. Escribano. J. Alarcón . 39

Capítulo III Problemáticas reológica y fabricación cerámica: reológica aplicada a los esmaltes. A. Ravaglioli 49

Capítulo IV Estimación del coeficiente de expansión térmica de fritas y esmaltes cerámicos. J. L. A moros, A. Belda, E. Ochandio, A. Escardino 63

Capítulo V Pigmentos rojos con elementos de transición o tierras raras para cerámica de alta temperatura. Dr. R. Olazcuaga 93

Capítulo VI Vidriados y Pigmentos. E P. Classer Ill

Capítulo VII Principales aditivos para la preparación y aplicaciones de esmaltes cerámicos: características e influencias sobre el comportamiento reológico, con referencia en particular a los ciclos rápidos de cocción. P Prampolini, Cerámico Spa., Italia 121

Capítulo VIII Reología de suspensiones de esmaltes cerámicos. P Blanchart 129

Capítulo IX Introducción a la colorimetría. V. Climent y J. Pérez Carpinell 143

Capítulo X Enfoques actuales en la búsqueda de pigmentos cerámicos. J. Carda, O. Monrós, M. A. Tena, P Escribano, V. Cantavella y J. Alarcón 165

Capítulo XI La producción de vidriados por aplicación en seco. F. Ambri, Montegibbio, Italy 183

índice de autores 199 índice de materias 201

p r e s e n t a c i ó n La Ley de Reforma Universitaria establece ya en su preámbulo que la Universidad es

un bien social, es decir, un Servicio más de la Sociedad que la crea, por tanto es ésa la que debe arbitrar los mecanismos oportunos para orientar, controlar y evaluar las actividades que en ella se realicen.

La mencionada ley establece que los profesores universitarios, entre las diversas labores que su actividad universitaria abarca, tienen «el derecho y el deber de investigan). La piedra angular del éxito o fracaso de la Investigación y el Desarrollo en la Universidad, es disponer de grupos de trabajo de calidad, con los medios económicos necesarios para llevarla a cabo y es en este punto donde radican, en la mayor parte de los casos, las dificultades para desarrollar una investigación de calidad.

Es de sobra conocido la desconexión existente entre el mundo universitario y el empresarial. No se trata de buscar culpables sino que habría que arbitrar los mecanismos de colaboración necesarios para reorientar, si fuera necesario, las investigaciones que en la Universidad se están realizando, atendiendo a las necesidades del mundo empresarial dado el vertiginoso avance de la Ciencia y la Tecnología.

La colaboración entre la Universidad y la Empresa sería altamente beneficioso para la Universidad no sólo porque puede representar una fuente de financiación adicional sino ̂ también acceso a medios no disponibles, intercambio de ideas con profesionales ajenos al mundo universitario, conocimiento de la demanda social, aplicación de los resultados de investigación, abordar problemas reales saliéndose de los puros teoricismos hacia los que se puede estar tentado, etc..

Desde el punto de vista de la Empresa, las ventajas podrían ir encaminadas hacia el estudio y tratamiento de los problemas que tengan planteados, el enriquecimiento con ideas y metodologías nuevas, la formación en un entorno próximo de plantillas especializadas en las técnicas y métodos que demanda la Empresa y la actualización de la formación universitaria de su propia plantilla.

No obstante, conviene señalar que la Universidad no debe caer en la tentación de convertirse en una «Oficina de Proyectos». Los temas que a ella se le encomienden deberían tener un mínimo de creatividad e innovación, tanto en proyectos a medio plazo como a largo plazo y no concebirla para resolver problemas puntuales e inmediatos.

El libro titulado «Nuevos Productos y Tecnologías de Esmaltes y Pigmentos Cerámicos», que tengo el honor de prologar, nace fruto de la colaboración entre la Universidad y la Empresa. Su contenido es de alta calidad científica y de gran aplicabilidad industrial. En su elaboración han intervenido científicos de gran renombre internacional y la temática se ha orientado de cara a satisfacer las inquietudes de las empresas del sector cerámico, concretamente, en la profundización del conocimiento en los campos de los esmaltes y los pigmentos. Es un buen ejemplo de cómo hay que caminar, para, en definitiva, prestar un mejor servicio a la Sociedad.

Purificación Escribano López Profesora Titular de Química Inorgánica

Universität Jaume I de Castelló

Nuevos Productos y Tecnologías de

Esmaltes y Pigmentos Cerámicos

Editores científicos: J. Ma. RINCÓN, J. CARDA y J. ALARCÓN

Faenza Editrice Ibérica y Sociedad Española de Cerámica y Vidrio CASTELLÓN