Phosphoric acid is one of the most important products in
chemical industry, where it is used in different industries,
such as food and fertilizer industries and so on .
This study focuses on the preparation of phosphoric acid
from Syrian phosphate in the laboratory by using the
hemihydrate method , and determines the best optimal
conditions for preparing this acid using this method .
The Purpose of this study was to evaluate and compare the shear bond strength
(SBS) of two composite repair systems to zirconia-ceramic with and without sandblasting.
This research showed the great importance for following studies of the effect of polluted phosphoric acid,
produced in General Fertilizer Company, on the high corrosion resisting alloys, to reach suitable alloys
for equipments and machines used for
its production, because of its high corrosion rates that create many
corrosion problems in these equipments and machines.
Welded joints corrosion phenomena for some kinds of stainless steels and nickel alloy was studied in
polluted phosphoric acid 37.7%H3Po4 using electrochemical techniques like Tafel polarization. Corrosion
rate of base metal and weld metal had calcu
lated & compared among these alloys.
Laboratory Test results showed the change in both corrosion rate and corrosion current densities (Icorr)
for tested alloys, and there is a clear difference between base metal and weld metal in most of tested alloys
, which lead to high corrosion rates of welded joint, and change in its properties then gets out of service in
some service conditions. The stainless steel 904L has low corrosion rates and low difference in corrosion
rates between base metal and weld metal, so it may be the most suitable alloy, among all the studied
alloys, for exploitation in polluted phosphoric acid 37.7%H3Po4 produced at the General Fertilizer
Company in Homs city.
to evaluate the shear bond strength(SBS) of a composite resin repair system to
zirconia-ceramic with and without water storage and thermo-cycling (WSTC).
Etching by phosphoric acid is considered an important factor to achieve
resin bonding to Primary enamel.
Bond strength was significantly higher in the third group (etching for
35sec) than the other groups (etching for (15), (25), or (45)sec).
The
re were no significant differences in bond strength between etch
durations: (15), (25), or (45) sec.
