Engineering Materials: Portland Cement: Definition, manufacturing by Rotary Kiln, role of gypsum, chemistry of setting and hardening of cement. Glass: Definition, manufacturing by tank furnace, significance of annealing, types and properties of soft glass, hard glass, borosilicate glass. Lubricants: Classification, mechanism, properties; viscosity and viscosity index, flash and fire point, cloud and pour point.

1. Engineering Materials: Portland Cement:
Definition, manufacturing by Rotary Kiln, role
of gypsum, chemistry of setting and hardening
of cement.
Glass: Definition, manufacturing by tank
furnace, significance of annealing, types and
properties of soft glass, hard glass, borosilicate
glass.
Lubricants: Classification, mechanism,
properties; viscosity and viscosity index, flash
and fire point, cloud and pour point.
Unit 4

2. The chief chemical components of Portland cement are calcium, silica,
alumina and iron. Calcium is derived from limestone, marl or chalk,
while silica, alumina and iron come from the sands, clays and iron
ore sources.

3. Manufacturing by Rotary kiln
A kiln (kil or kiln) is a thermally insulated chamber, a type of oven, that produces temperatures
sufficient to complete some process, such as hardening, drying, or chemical changes.

4. Rotary kiln Process

7. Gypsum is a mineral and is hydrated calcium sulfate in chemical form.
Gypsum plays a very important role in controlling the rate of hardening
of the cement. During the cement manufacturing process, upon the
cooling of clinker, a small amount of gypsum is introduced during the
final grinding process.
When cement is mixed with water, it becomes hard over a period of
time. This is called setting of cement. Gypsum is often added to
Portland cement to prevent early hardening or “flash setting”, allowing
a longer working time. Gypsum slows down the setting of cement so
that cement is adequately hardened.
Chemical composition of Portland Cement:
Portland cement is made up of four main compounds: tricalcium silicate
(3CaO · SiO2), dicalcium silicate (2CaO · SiO2), tricalcium aluminate
(3CaO · Al2O3), and a tetra-calcium aluminoferrite (4CaO · Al2O3Fe2O3)
Role of Gypsum: CaSO4.2H2O

13. Portland Cement: Structure

23. Tank Furnace
Manufacturing of Glass by tank furnace

30. Annealing of Glass

31. Annealing Process of Glass Bottles with Them Being Removed From the Conveyor Afterwards

35. Chemical Structure of Soda-Lime Glass

36. Chemical Structure of Soda Glass

37. Borosilicate Glass
Borosilicate glass is a type of glass with
the main glass-forming constituents' silica
and boron oxide.

38. Chemical Structure of Borosilicate Glass

39. What are the benefits of borosilicate glass?
•Optical Clarity
•Cleanability
•Compact Design
•Corrosion Resistance
•Temperature Range
•Structural Integrity due to Low
Thermal Expansion
•Affordability
•Inert Behavior

40. Lubricants
A lubricant is a substance, usually organic, introduced to reduce friction
between surfaces in mutual contact, which ultimately reduces the heat
generated when the surfaces move.
Dry lubricants or solid lubricants are materials that, despite being
in the solid phase, are able to reduce friction between two surfaces
sliding against each other without the need for a liquid oil medium.
The two main dry lubricants are graphite and molybdenum disulfide.

50. The SI unit of viscosity is poiseiulle (PI). Its other units are
newton-second per square metre (N s m-2) or pascal-second
(Pa s.) The dimensional formula of viscosity is [ML-1T-1].
The viscosity of liquids decreases rapidly with an increase in
temperature. Thus, upon heating, liquids flow more easily.

52. Flash Point and Fire Point
The observed temperature when the flame momentarily ignites the
vapour/air mixture is the Flash Point. The ignitions repeat as the liquid
temperature continues to rise. The observed temperature when the
burning becomes continuous is the Fire Point.

53. Cloud Point and Pour Point

54. Temperature reduce
Cloud Point Pour Point