Waste/polluted water discharged from electroplating, blast furnace and coal mining industries contain mainly __________ substances.

Coal mines drainage waste water (acidic in nature) results from the earth's water percolating through the voids created in coal bed during mining. This polluted water which either drains out naturally to water courses or are removed before starting the mining is

A

Neutralised by alkali treatment

B

Left as such without any treatment

C

Diluted with fresh water to reduce its acidity

D

None of these

In the blast furnace, incorporation of water vapour in the blast gives the following effect.

A

Increases the reducing potential of the gas

B

Increases the flame temperature

C

No significant change occurs

D

Increases the hydrogen content in the metal

Thermal efficiency of blast furnace stoves used for heating blast (air) may be about __________ percent.

A

20

B

40

C

60

D

80

Oilish impurities present the effluent discharged from the electroplating industry is normally not removed by

A

Chemical coagulation

B

Floatation & skimming

C

Centrifugation

D

Ultrafiltration

Operation of blast furnace stove is based on the principles of a __________ furnace.

A

Regenerative

B

Recuperative

C

Both A and B

D

Neither A nor B

Blast furnace coke is made from coal by

A

Low temperature carbonisation

B

High temperature carbonisation

C

Medium temperature carbonisation

D

Heating the coal in an oven in presence of air

Caking index of coal blend used for blast furnace coke making is about

A

8

B

12

C

22

D

36

Blast furnace slag is mainly molten

A

Sand

B

Magnesium silicate

C

Calcium silicate

D

Iron pyrite

Blast furnace gas constitutes mainly of

A

N₂ & CH₄

B

N₂ & H₂

C

N₂ & CO

D

CH₄ & CO₂

Oil and grease present in an emulsified state in waste water discharged from industries can be removed by

A

Biological oxidation

B

Skimming off

C

Settling out using chemical reagents

D

Chlorination

Waste/polluted water discharged from electroplating, blast furnace and coal mining industries contain mainly __________ substances.

Related Questions