Basic Civil Engineering Multiple Choice Questions on “Manufacture of Tiles”.
1. How many operations are involved in the manufacturing of tiles?
a) 5
b) 6
c) 10
d) 8
Answer: b
Clarification: The main 6 operations are a selection of suitable clay, preparation of clay, moulding, drying and shaping, burning and cooling.
2. What type of clay is selected for tile manufacture?
a) Slightly wet
b) Sticky
c) Dry
d) Rich
Answer: a
Clarification: Clay is cleaned and mixed with other additives. It is stirred in water and allowed to settle. Then slightly wet form is taken.
3. Secondary crushing of small lumps of clay to particles is carried out in:
a) Jaw crusher
b) Ball mill
c) Muller mill
d) Gyratory crusher
Answer: c
Clarification: Primary crushing of clay to small lumps is carried out in jaw crusher or gyratory crusher. A third particle reduction is carried out using ball mill.
4. At what point is a glaze applied to a tile?
a) Finished tile
b) Drying
c) Placing
d) Firing
Answer: d
Clarification: Glaze is a glass material designed to melt on to the surface during the firing process. It then adheres to tile while cooling.
5. Which of the following is matched properly?
a) Ribbon mixer-helical vanes
b) Shell mixer-revolving plows
c) Intensive mixer-two cylinders joined into a V
d) Pack mixer-uses water
Answer: a
Clarification: These are used for mixing the batched raw material. Shell mixer is the one that consists of 2 cylinders joined into a V. Intensive mixer uses rapidly revolving plows.
6. What is the meaning of slip?
a) Dry mixture
b) Impurities in mixture
c) Water filled mixture
d) Different sized mixture
Answer: c
Clarification: For fine grinding, water is added to the ball mill, where clay particles are obtained as wet mixture. It is called wet milling. Then it is followed by dry milling.
7. How is water content in the slip or slurry removed?
a) Filter pressing
b) Spray drying
c) Sun drying
d) Vacuum pressing
Answer: a
Clarification: If wet milling is carried out, excess water is removed by spray drying. If dry milling is carried out after wet milling, filter pressing is used. It removes 40-50% of moisture.
8. Which method of forming is used for heavily profiled tiles?
a) Dry pressing
b) Ram pressing
c) Pressure glazing
d) Extrusion
Answer: b
Clarification: In Ram pressing, extruded slugs are pressed between 2 halves of hard mould mounted in a hydraulic press.
9. Which of the following is not a method of drying?
a) Impulse drying
b) Infrared drying
c) Kiln drying
d) Tunnel driers
Answer: c
Clarification: Impulse drying uses pulses of hot air flowing in the transverse direction. Tunnel driers use gas, oil, infrared lamps or microwave energy. Infrared drying is used for thin tiles.
10. In waterfall method of glazing, glaze is fed through rotating disc that flings glaze onto tile.
a) True
b) False
Answer: b
Clarification: The above described method is employed in a centrifugal or discing method. In the waterfall or bell method, a stream of glaze falls onto tiles, moving below on a conveyor belt.
11. Which step removes volatiles from the material during firing?
a) Glost firing
b) Single firing
c) Fly firing
d) Bisque firing
Answer: d
Clarification: Tile prepared by dry grinding requires 2 step process. In the first step, tile passes through low temperature firing, called bisque firing.
12. Fluorine emission is a pollutant generated during the manufacturing process.
a) True
b) False
Answer: a
Clarification: Pollutants released are lead, fluorine, waste water, etc. Fluorine emission can be controlled by using scrubbers.
.