In many industrial
operations metals such as steel and iron are subjected to very high temperature
which often leaves a discoloring oxide layer or scale on the surface. The process
of hot rolling, drawing, annealing and molding of metals result in the
deposition of organic impurities, stains, rusts and scale which impede further metal
processing. In industries same metals are used for a long period which makes
them vulnerable to development of rust and surface deformation.
Pickling is the
conventional method practiced in industries for removing rust and scales from
metal surface. It is the removal of any high temperature scales from metal
surface by chemical means. It involves dipping of the metal work piece in acid
solution referred to as “pickle liquor”. Earlier sulphuric acid was used in
pickling process but now HCL has taken the prime position as it pickles much faster
with minimum loss of base metal.
Corrosiveness of acid
makes it difficult to handle. The acid reduces the protective oxide film on
metals and thus expose the underlying metal to corrosion. The hydrogen present
in the acids further reacts with the metal surface and ultimately builds up cracks.
The acid often cause dissolution of the pure metal leading to metal loss.
An acid inhibitor is thus added to the pickling solution to reduce corrosion and prevents the metal from dissolving or becoming pitted.
Inhibitors may be natural or synthetic organic compounds which are added to
pickling acid solution to reduce metal corrosion .They slow down the reaction
between acid and base metals which help in controlling excessive fume
generation during pickling. Inhibitor also aids in controlling pickling rate.
Rodine 85 is a low
foaming liquid corrosion inhibitor intended for use in sulfuric acid pickling
operations on various types of metals like copper, brass, nickel and all type
of steel. It is formulated using 1,
3 Diethyl Thiourea, Propargyl alcohol, Formaldehyde, Substituted triazine &
O-Toluidine and detergent. Rodine 85 shows activity at any acid
concentration. Rodine 85 is an effective inhibitor for phosphoric and acetic
acids, as well as sulfamic, citric, oxalic, and sodium bisulfate solutions in
pickling and industrial cleaning operations.
Rodine
85 reduces corrosive attack of acids on the clean metal to a minimum, which
reduces the amount of sludge formed in pickling baths also it helps in reducing the consumption of acid and prolongs
the life of the bath. It passivates the metal surface, to a considerable degree
and makes it highly corrosion resistant. Rodine 85 allows pickling baths to be
used at higher temperature, which leaves the surface of the metal chemically
clean and ready for the application of finishing coatings such as plating, painting
or lacquering; It improves the appearance of the pickled metal by creating a
uniformly whiter (i.e. more silvery) surface, thus improving its solubility.
Other advantages are the elimination of gases and fumes in the pickling process
and the prevention of acid brittleness of the steel.
Rodine 85 dosage
greatly depends on the type of metal, the temperature of operation and the
sequence of cleaning operation. The recommended amount of Rodine 85 to be used
for pickling is always given in percent by volume of the concentrated acid,
regardless of the degree of acid dilution used. RODINE 85 should be used at a
concentration ranging from 0.05 to 0.30 percent by volume of the diluted acid
regardless of the degree of acid dilution used. In addition, it is recommended
that Rodine 85 inhibitor be used at a concentration not less that 0.5% by
volume of the concentrated liquid acid or not less that 0.5% by weight of the
concentrated solid acid, regardless of the temperature of the industrial
cleaning operation.
The key features can be
summarized as follows -
- Strong inhibitor with detergent improves rinsability
- Aids in attaining maximum cleanliness on nickel work
- Low foaming inhibitor for general purpose inhibition
ChemEqual, the largest chemical marketplace gives the opportunity to buyer to compare and buy Rodine 85 chemicals and its equivalents from the global manufactures.
