Quiz 7 Flashcards
An aggregate of minerals from which metal maybe extracted at a
profit is called
a . concentrate c . middling
b . ore d . gangue minerals .
b
The formula of Magnetite is
a . Fe203 c . Fe2O3 H2O
b . Fe304
b
The formula of enargite is
a . Cu3AsS4 c . Cu2As2S5
b . Cu3AsS3 d . CuAsS2
a
A most common gold ore is
a . gold - quartz c . pyritic ores
b . telluride d . Au associated with Cu
a
A most common important ore minerals of manganese is
a . pyrolusite c . Rhodochiosite
b . psilomelane d . millerite
a
The process of separating the ore minerals from the gangue
minerals is
a . ore dressing c . milling
b . extractive metallurgy d . leaching
a
The main object of comminution is
a . liberation of ore minerals from the gangue minerals
b . establish uniform fineness of the lead
c . homogently
d . enhance solubility of ground product
a
The law that states that the energy consumed in grinding is
proportional to the new surface area created is
a . Bond’s Law c . Kick Law
b . Hettinger’s Law d . Newton’s Law
b
A gyratory crusher is
a . primary c . tertiary
b . secondary d . forth stage crusher
a
The part of the crusher that determines the maximum size that will
enter the crusher
a . throat c . gape
b . mouth d . angle of nip
C
In ball milling , the ball charge centrifuge when the
a . critical speed is exceeded c . when less water is added
b . critical speed is not reached d . when ball mill is operating , under
load reduce energy
a
The purpose of close circuit grinding is
a . lengthen the residence of ore inside the mill
b . prevent ore - grinding
c . reduce oversize in the product
d . reduce energy consumption
b
The primary grinding , the ideal circulating load ratio is
a . 150 % c . 250 %
b . 200 % d . 300 %
c
In Tyler standard series , the openings are regulated such that the
ratio in any screen to the next screen is
a . 1.414 c . 2.000
b . 1.750 d . 2.150
a
The mesh number of a screen
a . no . of opening per linear inch c . opening in inch
b . opening in cm d . opening in mm
a
The method of separating a mixture of minerals into two or more
products on the basis of velocities at which the grains will fall thru
a fluid medium is called
a . classification c . heavy media separation
b . sedimentation d . elutriation
a
Hindered settling refers to
a . settling of minerals in the thick pulp
b . settling of minerals in water
c . settling of minerals in dilute pulp
d . settling after agitation
a
Cyclone is a
a . classifier c . mixing
b . de - watering d . thickening
a
A thickener is
a . de - watering equipment c . sizing
b . mixing d . dissolution equipment
a
A middling is concentration refers to
a . feed to concentration system c . contains ore and minerals
locked together
b . by product d . discarded portion of the concentration system
C
One of this concentration processes is not gravity method
a . panning c.tabbling
b . jigging d . hand - picking
d
Commercial sink - and - float processes used as medium
a . magnetite c . galena
b . ferrosilicon d . carbon tetrachloride
b
In ore dressing , sulfide minerals respond most readily to
a . flotation c . gravity concentration
b . amalgamation d . hydraulic classification .
a
A most common frothier used in flotation is
a . ethyl alcohol c . minerec
b . pine oil d . solid hydrocarbon
b
A most widely used collectors are
a . xanthates c . thiosulfates
b . sodium sulfides d . cresylic acid
a
Substances that inhibits flotation of minerals are called
a . conditioner c . depress ore
b . activators d . modifiers
c
The flotation process of recovering two or more minerals as sep-
arate concentrate is called
a . bulk sulfide flotation c . differential flotation
b . selective flotation d . stage flotation
C
The conditioner used to regulate alkalinity of the pulp is
a . NaCN c . soda ash
b . CaO d . Na2S
b
The metallurgical recovery refer to
a . wt . of concentrate divided by the wt . of feed
b . percent of metal contained in the concentrate against metal in
the ore
c . percent mineral recovered against recoverable minerals
d . distribution percentage of metal in feed
b
If f , c , and t are corresponding metal assays as feed , concentrate
and tails , then the ratio of concentration maybe expressed as
a . ( c - t ) / f c . ( ft ) / ( c - t )
- b . ( c t ) / ( ft ) d . ( ft ) ( ct )
C
Calculated head refers to
a . assay of feed
b . grams of metal in product / 100 gram feed
c . grams of metal recovered in concentration
d . metals in by - product
b
Pulp density is the
a . weight of a unit volume of pulp
b . weight of dry solids in the pulp
c . ratio of the water to solids by weight
C
Avogadro’s number is the number of atoms in one gram atom
which is
a . 3.4 x 1014 c . 5.0 x 1032
b . 6.02 x 1023 d . 22.4 x 102
b