USE DH-3237 IRON-STEEL RUST
DH-3237 is a rust remover for iron and steel
pieces. It has phosphoric acid as its main
component, comprising also complexes of
other organic acids and non-organic acids as
well as some kinds of surface activators.
It being used to remove rust before the
workpieces are parkerized can bring about
the two-way effect --- not only the results
of acid pickling shown on he surface more
satisfactory, but the surface is also no
longer so liable to get rusty again(than if
hydrochloric acid is used instead). So it is
helpful to produce a more lasting
DH-3237 iron-steel rust
remover being used in pickling workpieces
with folds, dog-ears and welding seams can
prevent rusting again of these hidden parts,
so that the quality of later processes can
Characteristics of the product
(a) As the rust
remover consists of various surface
activators, its actions of permeating,
dispersing, moistening and carrying-away can
speed up the clearance of rusty crusts and
other impurities attached to the surface of
the steel material, and improve the results
of pickling to get the material ready for
(b) The compounds in this dust remover can
get into drastic complexing with Fe3+, and
thus quicken the process of rust removing.
(c) This dust remover is nonpoisonous, very
steady in property, without any peculiar
smell, doing no harm to users and giving no
acid mists. It has not any erosive effects
to the electric and mechanic installations
and the workshop itself.
Main technical indexes
Appearance --- colorless or light yellow.
Physical-chemical properties ---
Specific gravity: 1.465 – 1.510
dissolved in water.
Density of the liquid to be used ---
1:2/3(to be diluted with water 2 or 3 times
the quantity of the original liquid.
The tank(1000L) --- in case the liquid is
diluted with water twice the quantity of
Let the tank contain at first 50% of the
Pour in DH-3237 dust remover about 500kg,
and stir the mixer.
Add some more water(total amount of the
mixer1000L), stir well.
Get 2ml of the mixer out to testify the
The liquid is always valid as long as its
general acidity keeps between 50-70pt, so
there is no need to make tests repeatedly.
Free acidity need not be tested.
Temperature and manner of application ---
Soaking at normal temperature (RT – 50°C)
Time duration ---
treatment of surface rust: 5 to 10 minutes.
For treatment of rusty
crusts: 10 to 20 minutes.
Supplement and adjustment --- in case 1000L
liquid is used.
density of the liquid gets lower during the
treating of the rusty material, the changing
density should be tested from time to time,
and extra agent should be supplied to
maintain a normal effective rate. Generally
speaking, adding every 4kg of the agent will
get the general acidity to increase by 1 pt.
Testing methods ---
General acidity: Transfer 2 ml of the
treating liquid with a suction pipet into a
250ml beaker, add 50ml of distilled water,
and then 5 or 6 drops of phenolphthalin.
Titrate the mixer with NaOH of 0.1N. When
the mixer changes from colorless to pink,
the number of ml of NaOH used will be the pt
value of the general acidity.
Quality of the container ---
pickling tank should be made of stainless
steel or carbon steel lined with glass fiber
reinforced plastic. The heat exchanger, the
sprayer nozzle, the piping and the pump
should be stainless steel parts.
9) Points for attention
This rust remover has a lower solubility of
iron, so when the density of Fe2+ reaches
65-70g/L, the liquid should be drained off.
The best way to get rid of deposits in the
tank is to pump the whole of the liquid into
a clarifying tower or clarifying basin, and
then return the clear liquid to the tank.
10) Package , storage
and transportation ---
Specifications: This product is a light
yellow liquid, containing no impurities and
insoluble substances. It can be stored for
long periods without deteriorating.
Storage, transportation and package: The
product is not an inflammable or explosive
substance, neither is it poisonous. It does
not demand any special storage and
transportation conditions. The normal
package is 30kg polythene plastic
containers. Other kinds of package are
available on customers’ requirements.