d3

From the analysis of fuels given below, what is the most suitable fuel for Cu melting at 1200øC?

%C %H %O %N %D %ash %H2O Cal.

Value

a) 19.7 16 38 42.14 0 0 0 2.35

b) 49.7 19.1 17.1 11.5 2.6 0 0 37.67

c) 87.3 6.2 2.9 1.5 0.8 0.3 1.0 37.91

d) 58.0 4.0 1.0 1.0 1.0 15.0 20.0 24.19

a) 19.7 16 38 42.14 0 0 0 2.35

3]Metal tempering is a simple heat treatment process normally carried out by combustion of a gaseous fuel or

electric heating. From the list of fuel analysis given below, what are the unsuitable fuels for tempering?

%C %H %O %N %D %ash %H2O Cal.

Value

1) 19.7 16 38 42.14 0 0 0 2.35

2) 49.7 19.1 17.1 11.5 2.6 0 0 37.67

3) 87.3 6.2 2.9 1.5 0.8 0.3 1.0 37.91

4) 58.0 4.0 1.0 1.0 1.0 15.0 20.0 24.19

a) 1 & 2

b) 3 & 4

c) 2 & 3

d) 1 & 4

b) 3 & 4

C/H ratio is a guide to the type of fuel used for metallurgical applications. Choose the fuel below with wrong C/H

ratio.

a) coal tar fuel is 14

b) coals have ratio of 10 to a very large value

c) petroleum hydrocarbon is 7 or 8

d) coal gas is greater than 4

d) coal gas is greater than 4

Coke is a cellular coherent mass produced by carbonization of coal. Which of the following has the correct coking

sequence?

a) coal soften->contract slightly->swell->solidify into coke

b) coal swell->soften->contract slightly->solidify into coke

c) coal contract slightly->soften->swell->solidify into coke

d) coal soften->swell->contract slightly->solidify into coke

a) coal soften->contract slightly->swell->solidify into coke

The syngas produced by gasifiers can be converted

to substitute natural gas (SNG). This involve 3 major steps (may not be in correct sequence):

1) methanation

2) CO2 is removed from the product which has been enriched in hydrogen

3) Treating syngas with steam by shift reaction

Which of the following steps has the correct sequence of conversion?

a) 1,2 & 3

b) 3,2 & 1

c) 2,3 & 1

d) 1,3 & 2

b) 3,2 & 1

3]The Orsat apparatus, which operates on the principle of selective absorption, can provide the percentage of CO2,

O2 & CO directly and that of N2 by difference. This absorption apparatus consist of three (3) absorption pippetes

containing potassium hydroxide (KOH), pyrogallic acid and cuprous chloride. Which of the following options of gases can

be absorbed by potassium hydroxide, pyrogallic acid & cuprous chloride, respectively?

a) O2, CO2, CO

b) CO2, O2, CO

c) CO, CO2, O2

d) CO2, CO, O2

b) CO2, O2, CO

3]Consider the combustion of a hydrocarbon fuels having the general formula CmHn. The formula & the C/H mass

ratio for the fuel can be deduced simply from its chemical composition. Its combustion yields CO2 & H2O. Which of the ff.

formula gives the correct stoichiometric fuel air ratio?

a) (12m + 2n) / (138.32m + 34.58n)

b) (12m + 1n) / (138.32m + 34.58n)

c) (12m + 1n) / (34.58m + 138.32n)

d) (1n + 12m) / (138.32m + 34.58n)

b) (12m + 1n) / (138.32m + 34.58n)

3]A gas mixture containing 50 mole% CO, 32 mole %H2, & 18 mole %H2O is heated at 927oC. What is the final

composition, assuming that it behave ideally at the water gas equilibrium.

H2 + CO2 --> H2O + CO -Go= 11774J @ 927oC

%CO %H2O %H2 %CO2

a) 40.34 9.66 41.66 8.34

b) 41.66 9.66 40.34 8.34

c) 41.66 8.34 40.34 9.66

d) 40.34 8.34 41.66 9.66

b) 41.66 9.66 40.34 8.34

3]A waste gas analysis shows a dry analysis of 6.94% CO2, 10.92% O2, and 82.14%N2. What can be deduced

about the combustion process as to its empirical formula for the hydrocarbon & its %excess air.

a) A heptane (C7H16) completely burn with 100% excess air.

b) A heptane (C7H16) completely burn with 50% excess air.

c) A propane (C3H8) completely burn with 100% excess air.

d) A propane (C3H8) completely burn with 50% excess air.

a) A heptane (C7H16) completely burn with 100% excess air.

[Day 3]A coal containing 75% C, 5.34% H2, 7.36% O2, 1.26% N2, 1.28% S, 9.76% ash is burn w/ 100% excess air. The

combustion rate of coal is 12 tons/hr and the mean gas velocity is 6.5 m/sec. What is the chimney diameter required if

the waste gas temperature is 237oC?

a) 4.59 m

b) 5.49 m

c) 3.95 m

d) 3.59 m

a) 4.59 m

3]It is desirable to supply an excess amount of air in the complete combustion of coke to CO2 for heat generation

because:

a) an adequate supply of nitrogen must be made available

b) a deficiency of oxygen results in the formation of CO w/ much lower BTU yield

c) the excess air will carry more water vapor

d) more volatile matter will be carried away

a) an adequate supply of nitrogen must be made available

The strain upon a material is relative displacement per unit length. What strain parameter is defined below?

a) strain, nominal

b) strain, shear

c) strain, normal

d) strain, true

e) strain, engineering

d) strain, true

2]This law quantitatively describes the linear relationship between the stress and strain characteristics of elastic

deformation. In the law, E is Young's Modulus.

å

E= -----

î

a) Hooke's Law

b) Young's Law

c) Fick's Law

d) Bragg's Law

e) Fourier's Law

a) Hooke's Law

2]Tensile strength, expressed in psi or Kgf/mm2

, is simply

a) stress/elastic strain

b) resistance to plastic indentation

c) fractional deformation, -l/l

d) maximum strength

e) resistance to plastic deformation

d) maximum strength

The toughness parameter of a material is expressed in what measurable unit?

a) Joule/m2

b) Joules

c) Pascals

d) Newtons

e) joule/m(m2

ù s ù oC)

b) Joules

2]It is the load divided at any instant divided by the cross-sectional area which it acts.

P

å = -------

A

a) True stress

b) Normal stress

c) Engineering stress

d) Nominal stress

e) Conventional stress

a) True stress

2]It is the load divided at any instant divided by the original cross-sectional area which it acts.

P

å = --------

Ao

a) True stress

b) Normal stress

c) Engineering stress

d) Nominal stress

e) Conventional stress

c) Engineering stress

The following are related to the proximate analysis of coals except:

a) moisture

b) ash

c) tar

d) volatile matter

c) tar

Which of the following denotes gross calorific power?

a) reference state is liquid water

b) reference state is gaseous water

c) fuel is at 250C

d) liquid fuels

e) solid fuels

a) reference state is liquid water

3] Which of the following is correct coalification process?

a) wood -> peat -> anthracite coal -> bituminous coal -> lignite -> graphite

b) wood -> peat -> lignite -> bituminous coal -> anthacite coal-> graphite

c) wood -> lignite -> anthracite coal -> bituminous coal -> peat -> graphite

d) wood -> peat -> bituminous coal -> anthracite coal -> lignite -> graphite

e) graphite -> peat -> anthracite coal -> bituminous coal -> lignite -> wood

b) wood -> peat -> lignite -> bituminous coal -> anthacite coal-> graphite

3]Coals are noncrystalline and are of infinitely variable compositions, thus, they should be classed as

a) ore

b) mineral

c) gangue

d) rocks

e) stones

d) rocks

3]This water gas is enriched with hydrocarbons obtained by thermal decomposition of petroleum oils.

a) carburetted water gas

b) oil water gas

c) natural water gas

d) LPG

e) Producer water gas

a) carburetted water gas

3]This gas is found in earth, trapped at great depths and under high pressure.

a) producer gas

b) water gas

c) oil gas

d) natural gas

e) LPG

d) natural gas

3]The maximum flame temperature theoretically attainable in burning a fuel-air mixture under given conditions is

the temperature of the products of combustion when the combustion is carried out adiabatically.

a) adiabatic flame temperature

b) isothermal flame temperature

c) maximum flame temperature

d) adiabatic fuel temperature

e) maximum fuel temperature

a) adiabatic flame temperature

3]This is the coherent residue from the destructive distillation of coal in the absence of air. The destructive

distillation is carbonization.

a) carbonized coal

b) destructed coal

c) coke

d) processed coal

e) metallurgical coal

c) coke

3]The following account for the characteristic structure of coke during coking except

a) fusion

b) volatilization

c) swelling

d) solidification

b) volatilization

3]Which coke oven wastes the valuable by-products of coking?

a) beehive oven

b) by-product oven

c) conventional coke oven

d) coke oven

a) beehive oven

3]This coke oven has greater flexibility in handling poorer coals and in controlling coke properties.

a) beehive oven

b) by-product oven

c) conventional coke oven

d) coke oven

e) coal oven

b) by-product oven

3]This fuel gas is made by treating coal or coke with a mixture of air and steam.

a) producer gas

b) blast-furnace gas

c) coal gas

d) water gas

e) oil gas

a) producer gas

3]This/These is/are noncondensable gas(es) obtained from the destructed distillation of coal.

a) producer gas

b) coke oven gas

c) coal gas

d) b & a

e) c & b

e) c & b

3]This gas is made by the reaction of steam with a hot bed of coal or coke.

a) producer gas

b) blast-furnace gas

c) coal gas

d) water gas

e) oil gas

d) water gas

3]These are substances which are burned to supply heat at usable temperature levels for metallurgical

operations on a commercial scale.

a) fuel

b) fuel oil

c) metallurgical fuel

d) bunker oil

e) coke

c) metallurgical fuel

3]Bituminous coal represents the largest single source of energy for metallurgical purposes. Evaluate this

statement:

"The largest portion of tha coal is burned

directly for metallurgical purposes."

a) true

b) false

b) false

3] The following are solid primary fuels except

a) anthracite coal

b) bituminous coal

c) lignite

d) peat

e) graphite

e) graphite

3]"Charcoal is completely different to coke."

a) true

b) false

b) false

3]The following are the principal fuel products used in metallurgical processes except

a) pulverized coal

b) coke

c) charcoal

d) gaseous fuel

e) fuel oil

c) charcoal

3]The reference state is H2O at the gaseous state, and the latent heat of vaporization is not included in the

calorific value.

a) net calorific value

b) gross calorific value

c) total calorific value

d) calorific power

e) high calorific power

a) net calorific value

3] The formula expressed below is low calorific power

= 81C + 340(H-O/8) + 225 - 5.84(9H+M) cal/kg

=146C + 610(H-O/8) + 40S - 10.5(9H+M) BTU/lb

a) Dulong's Formula

b) Law of Combustion

c) Combustion of Coal Theory

d) Combustion Equation

e) Rittinger's Law

a) Dulong's Formula

3]Gross heating value of solid and liquid fuels are determined using:

a) a muffle furnace

b) an oxygen calorimeter

c) a combustion tube

d) a test tube

e) a fuel tube

b) an oxygen calorimeter

3]During combustion of fuels enriching the combustion air with oxygen will

a) decrease combustion temperature

b) have an effect on combustion temperature

c) increase combustion temperature

d) increase the nitrogen content of the flue gas

e) increase the oxygen content of the flue gas

c) increase combustion temperature

3]Combustion of a fuel with just its theoretical amount of air will result in

a) the maximum percentage of available heat

b) the maximum fuel comsumption

c) increase of the volume of flue gas

d) a and b

e) a, b and c

d) a and b

3]The effect of moisture in a given quantity of fuel is

a) reduce the available heat

b) increase the available heat

c) reduce the waste heat in the flue gas

d) produces more methane in the flue gas

e) none of the above

a) reduce the available heat

3]The heating value of bituminous coal compared to lignite is

a) equal

b) higher

c) lower

d) both are incomparable

b) higher

3]The _____________ of matte smelting furnace consists of silica sand rammed with binder and sinter in place.

a) sidewall

b) roof

c) hearth

d) slag line

e) tapping hole

c) hearth

3]Essential tools in interpreting and predicting structures of refractory bodies and structural changes during firing

and service.

a) Ellingham diagram

b) Equilibrium diagram

c) Pyrometers

d) expansion and shrinkage

e) fusion and softening behavior

b) Equilibrium diagram

3]Reheat furnace ____________ are normally constructed of several courses of standard bricks.

a) roof

b) walls

c) hearths

d) covers

e) none of the above

b) walls

3]The method of measuring the fusion and softening behaviour of refractories at high temperature.

a) PCE

b) Seger Cone Equivalent

c) pyrometric method

d) furnace heating

e) only a and b

e) only a and b

3]Silica grains rammed and sintered in place in the lining of ______________ for melting cast iron.

a) cupola

b) blast furnace

c) induction furnace

d) electric arc furnace

e) converter furnace

a) cupola

3]Expansion and shrinkage of refractories does not occur by except

a) allotropic changes and changes in structure / phase composition

b) change in temperature

c) elastic and plastic deformation

d) very high temperature

e) a, b and c

e) a, b and c

3]Refractory chromite compared to metallurgical chromite has

a) higher percentage of Cr2O3

b) higher ratio of Chromium to Iron

c) both are just the same

d) low percentage of iron

e) none of the above

e) none of the above

3]Refractories which are universally used in all types of furnaces except for places where very high

temperatures and severe chemical attack by slag.

a) basic refractories

b) silica refractories

c) fireclay refractories

d) chromite refractories

e) special refractories

c) fireclay refractories

3]Insulating refractories have

a) high thermal conductivity

b) low bulk density

c) porous

d) a and b

e) b and c

e) b and c

3]The principal constituents of most basic refractory materials

a) burnt dolomite

b) CaO

c) Cr2O3

d) MgO

e) CaCaO3

d) MgO

3]Refractory bricks commonly used at the slag line of basic electric arc furnace

a) chromite

b) magnesia

c) silica

d) fireclay

e) carbon

b) magnesia

3]Basic electric arc furnace hearths are commonly lined with granular __________ rammed and sintered in

place.

a) magnesia

b) chromite

c) silica

d) dolomite

e) any of the above

a) magnesia

3]Major types of mortars

a) gypsum

b) cement

c) air-setting

d) heat-setting

e) c and d

e) c and d

3]Cupolas are normally lined with ______________ bricks.

a) alumina

b) magnesia

c) fireclay

d) silica

e) dolomite

d) silica

3]The prime cause(s) of refractory body failure

a) chemical attack

b) softening

c) spalling

d) all of the above

e) none of the above

d) all of the above

3]Basic oxygen furnace converters are normally lined with

a) magnesia bricks

b) tar-impregnated dolomite bricks

c) silica bricks

d) carbon blocks

e) any of the above

b) tar-impregnated dolomite bricks

3]The prime cause of spalling is that stresses set-up in the bricks by

a) abrasion

b) mechanical stress

c) temperature gradient

d) slag

e) melt

c) temperature gradient