Quiz 6 Flashcards
ln sampling of pulp stream, the following statements are correct
except:
a.Material is sampled at the point of free fall discharge
b.Cutter should cut parallel to the stream
c.Cutter covers the whole stream
d.Cutter moves at constant speed
b
In the method of tailing disposal, the dam is raised. This has the
advantage of requiring smaller volumes of sand fill to raise crest to
any given height. The dam can be raised more quickly and there
is more trouble keeping it ahead of the tailings pond during the
early stages of construction.
a.Upstream method
b.Centerline method
c.Downstream method
d.Rightstream method
e.Leftstream method
b
Sedimentation produces 55-65% up to 80% solids by weight.
Filtration produces 80-90% solids. Thermal drying produces:
a.About 95% solids by weight
b.90-100% solids by weight
c.92-97% solids by weight
d.95-100% by weight
e.exactly 1005 solids by weight
a
In fire assaying, this is usually blue-gray in color nearing galena
in composition and is very brittle.
a. Dore
b.Speiss
c.Slag
d.Pb button
e.Matte
e
Bone ash cupel is made from the calcitation of animal bones
characterized by the presence of organice matte and carbonates,
nitrates, etc. which can decompose at cupellation temperature
and is undesirable because of the evolution of gases causing:
a.Sprouting
b.Splitting
c.Breakage
d.Spattering
e.Spitting
e
The following are reducing agents in fire assaying except:
a.Cream of tartart
b.Flour
c.Charcoal
d.Iron
e.Cryolite
e
Given the screen efficiency equation: E=(10,000u)/(UF), where
U=undersize; F=feed; and u=% undersize in feed, is it possible to
have 100% efficiency?
a. True
b.False
b
Assume that the capacity of a ball mill varies directly with the
length of the mill and with the 2.9 power of the diameter. If a 4’x4’
ball mill has a capacity of 30 tons per day, calculate the diameter
of a ball mill 5 feet long and that would grind 100 tons per day.
a.6.82ft
b.5.43ft
c.6.70ft
d.5.60ft
d
A CIP plant treats 1000 DMTPD of ore with specific gravity of 2.62
and slurry feed density at 1362 kg/m3. Calculate the following:
9.1.Grams gold to be adsorbed on carbon surfaces:
a.12530.21gms
b.11972.81gms
c.11449.97gms
d.11688.51gm
e.11815.22gms
9.2.Head grade in gms/ton if the assay results are as follows:
Residue, g/t Soln, ppm
Feed 3.018 0.306
Tails 0.352 0.035
a.3.370 b.3.521 c.3.324 d.3.156 e.3.485
9.3.Gold recovery:
a.85.01 b.87.65 c.87.91 d.89.89 e.90.70
a
A flotation plant treats 800 tons of solid per hour. The feed pulp
containing 45% solids by weight is conditioned for 10 mins with
reagents before being pumped for flotation. Calculate the volume
of conditioning tank required. Density of solids is 2700 kg/m3
a.78.0 m3
b.77.93 m3
c.211.12 m3
d.212.35 m3
e.200.16 m3
d
The error of separation defined as the half difference between the
density when 75% is recovered to the tank A and that which 25%
is recovered to float B. Its called ideal separation when its value is
zero. Ep=A-B/2
a. Ecart partition
.Ecart probable
c.Ecci partition
I.Ecci probable
Elton partition
b
A CIP plant treats 4200 MT of ore in 24 hrs. It consumes 1.1 kg
NaCN per MT of ore. If the cyanide solution is 15% solution, how
much cyanide solution should be added in CC [per minute?
a.25,465 cc/min
b.8,000 cc/min
c.22,600 cc/min
d.21,389 cc/min
e.24,712 cc/min
d
Calculate tons of material going to the tailings and the recovery
if 350.9 of concentrate are produced assaying 53% metal from a
head grade of 4.65% and tailings 0.9%.
a.3541 tons, 70%
b.3743 tons, 79%
c.4589.11 tons, 66.32%
d.4769.21 tons, 82.04%
e.4875.2 tons, 82.04%
e
Fusion is one process in fire assaying where the flux with samples
to be analysed for Au are placed in fire assay crucibles and melted
in the furnace. What is the required temperature for the process?
a.800deg C
b.700deg C
c.900deg C
d.1050deg C
d
In fusion process in fire assaying, why do we require a certain
temperature of the furnace during the stage assaying samples for
Au determination.
a. Because this is the maximum temperature of the furnace b.Because of the boiling point of the flux
c.Because of the boiling point of CU, Fe, Pb, Zn, Te, and Ag d.Because of the boilih point of Au
d
In fire assaying, we have the color scale of temperature in the chamber of the furnace. What is the estimated temperature of the
furnace if it is observed as orange color in the chamber?
a.850deg C
b.800deg C
c.950deg C
d.900deg C
d
In preparing beads before adapting acids, they are flattened on an anvil and rolled out to a thickness desired and to prevent it from
crushing when annealing them. What is the desired thickness of
the beads?
a.0.0001 inch
b.0.0015 inch
c.0.001 inch
d.0.01 inch
d
It originated from the custom of the assayers of adding silver until
the gold was about a fraction of the whole. What ratio is silver to gold do they consider to be necessary for parting? a.2Ag.2Au
b.3Au.1. Ag
c.3Au.2Ag
d.3Ag. 1Au
d
According to their oxidizing or reducing character in the crucible
assay, classify the following ores: Siliceous, oxide and carbonate
ore, ore containing no sulphides, arsenides, antimonides, tel-
lurides
a.Ores having reducing agent
b.Ores having reducing agent c.High sulphide ores
d.Natural ores
d
Inscorification, the color of the slags resulting from crucible assays is often indicative of the metal present. What is the metal present if the slags is shaded with green color?
a.Copper
b.Cobalt
c.Zinc
d.Fe
d
What is the most serious objection in scorification process with
regards to losses?
a.Slagging
b.pouring
c.Oxidizing
d.Spitting
d
