MECHANISMS OF REACTIONS AT THE INTERFACE OF SOLID PHASE/LIQUID ELECTROLITE
Main researcher
: ŠARC-LAHODNY, OLGA (46003) Assistants
DRAGČEVIĆ, ZVONKO (10420)
KRSTULOVIĆ, LJILJANA (24080)
IVIĆ, JURE (165371)
KULUŠIĆ, BISERKA (24616)
Type of research: applied Duration from: 01/01/91. to 01/01/95. Papers on project (total): 1
Institution name: Rudarsko geološko naftni fakultet, Zagreb (195) Department/Institute: Mining, Geology and Petroleum Engineering Faculty of the Univers ity of Zagreb, Address: Pierottijeva 6 City: 10000 - Zagreb, Croatia
Communication
Phone: 385 (0)1-442-409
Fax: 385 (0)1-440-008
Summary: 1. Mechanisms of Reaction in Coorosion and Protection of
Metals 1.1. Synergistic action of certain non-toxic compounds has been
studied along with some passivating inhibitors commonly used for the
protection of steel against corrosion in neutral media. Passivating
inhibitors, as nitrite, are not ecologically acceptable and if they could
be replaced completely or at least partly by non-toxic substances, the
procedure would be of interest in environmental protection. 1.2. The
composition and the procedure of treatement of sacrified electrodes for
cathodic protection of steel in the seawater has been studied. The
alloying elements, Zn, Pb, Sn, and Sb in aluminium anodes have been
investigated. The protection effects was estimated by the lowering of
electrochemical potential in the region of immunity and by the
measurements of protective current. 1.3. Completely clean surfaces of
metals are not always available for the protection with inhibitors in the
practice, therefore the mechanism of interaction of inhibitors with the
corrosion products has been studied. Some natural compounds, ecologically
acceptable, were investigated in the presence of the rust on the steel. 2.
Synthesis and Surface Properties of Aluminosilicates. 2.1. Factors
influencing the synthesis of kaolinite in the system Alumina-Silica-Water
under hydrothermal conditions were defined in order to get a well
crystallized product. 2.2. Pillar-clays were synthesized and their surface
area, the cation exchange capacity and thermal stability detected.
Keywords: 1. corrosion, metals, inhibitors, synergistic action, ecologically acceptable, cathodic protection, sacrified electrodes, rusted steel, oil and gas production corrosion 2. synthesis, surface properties, aluminosilicates, kaoline, "pillar-gline"
Research goals: 1. The use of corrosion inhibitors, successfully
applied in the practice has been actually limited or completely restricted
due to their toxic properties, as of chromate, or because provoking the
eutrophycation, as nitrite or inorganic phosphate, in natural and seawater.
To raplace these toxic compounds it is necessary to understand the
mechanism of action of newly intruduced low toxic substances, and to define
the mixture of compounds with synergistic behaviour. Successful results in
the inhibition of steel in the tap water and in the seawater are expected.
In the process of inhibition of metals against corrosion very often one is
the dealing with partly corroded surface covered with the corrosion
products. Certain natural substances are investigated in order to detect
their action on rusted steel. Sacrified anodes for the cathodic protection
have been studied, mainly aluminium alloys and zincated aluminium to
obtained the protection device with optimal life time of the electrode and
the minimum of its passivation. 2. The synthesis of aluminosilikates in the
solutions of electrolites has been studied under hydrthermal conditions.
Synthesis was carried out at temperatures lower than indicated in the
equilibrum diagram for the stability phases. "Pillar"-clays were prepared
and thier surface properties defined. Obtained products can be applied in
industrial catalyisis, as adsorbents, molecular sieves and in drilling
muds.
COOPERATION - PROJECTS
Name of project
: Corrosivity of Seawater Name of institution: European Federation of Corrosion, The Institute
of Materials 1 Carlton House Terrace City: SW1Y 5DB - London, UK
COOPERATION - INSTITUTIONS
Name of institution
: Zavod za istraživanje korozije i za
desalinaciju HAZU Type of institution: State institute Type of cooperation: Other City: 20000 - Dubrovnik, Croatia
Name of institution
: European Federation of Corrosion Type of institution: International organization Type of cooperation: Other City: Frankfurt, Njemačka
OTHER ACHIEVEMENTS
Name
: Organization of the 7th International Congress of ICSOBA
(International Committee for the Study of Bauxite, Alumina and Aluminium). Type of achievement: Other Authors: Olga Šarc-Lahodny (46003), General Secretary of ICSOBA Other information about the project.