Ceramics

Give examples (2) of equipment for crushing brittle raw materials

Hammer Crusher,, Jaw Crusher

Give examples (3) of mills used in ceramic industry

Ball mill, Roller mill, Atritor mill

Could you explain a term “calcination”

Calcination is a heat treatment in order to decompose the materials especially carbonate to its oxide state. It’s use only to simple oxides, is a endothermic reaction,

Give an example (1 reaction) of solid state synthesis of mixed oxides

CaO + TiO2 -&rt; CaTiO3 (perovskite, ferroelectric)

Give an example (1 reaction) of carbothermal synthesis of non-oxide ceramic powder

Si + C = SiC (???) Si3N4 + 3C ⇌ 3SiC + 2N2 (???)

Obligatory requirement for self-propagating high-temperature synthesis (SHS) powder

exothermic reaction - the rate of heat losses from the closed system is slower from the rate of the heat evolution: borides, carbides, nitrides, silicides - ignition

Give examples of chemical methods of ceramics powders manufacturing

Wet chemical methods: -spray frying; - freeze drying; - co-precipation; - pecchini method with critic acid; - hydrothermal methods; - SOL-GEL

Description of spray-drying method fo ceramic powder

Spray-drying is a process of producing a granulates ,flowable powder of uniform bulk density. It is process by which fluid feed material is transformed in a dry powderby spraying the feed into a hot drying medium (gas) EVAPORATION -&rt; PRECIPITATION -&rt; DRYINGE -&rt; DECOMPOSITION

Description of freeze drying method for ceramic powder

Freeze-drying is used to create a formable powder from a sprayed slurry mist. Freeze-drying creates softer particles with a more homogeneous chemical composition than traditional hot spray drying, but it is also more expensive.

.List the reagents (3) in sol-gel method for ceramic powder production

- water - alkoxides - acid

Principles of ceramic nanopowder production via gas-phase methods

EVAPORATION-CONDENSATION, DECOMPOSITION OF GASEOUS COMPOUNDS, REACTIONS BETWEEN GAS PHASES

What does it mean: “rheology”

RHEOLOGY: hydrodynamics of dispersed systems: solid+liquid

Parameters describing powder properties(3)

Particle size distribution, Apparent mean size, Specific Surface area (SSA)

Why powder particles from agglomerates?

Because it wants to reduce the surface energy

How water presence affect Hamaker’s constant of powder?

Water presence reducecs Hamaker's constant