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MPC711S - Mineral Separation Process 314 - 2nd OPP - JUN 2023 |
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nAmlBIA UnlVERSITY
OF SCIEn CE Ano TECHn OLOGY
FACULTY OF ENGINEERING AND THE BUILT ENVIRONMENT
DEPARTMENT OF CIVIL, MINING AND PROCESSENGINEERING
QUALIFICATION : BACHELOR OF ENGINEERING IN METALLURGY, CHEMICAL ENGINEERING &
MINING ENGINEERING
QUALIFICATION CODE:
08BEMT /08BECE/08BM EG
LEVEL: 7
COURSE CODE: MPC711S
COURSE NAME: MINERAL SEPARATION PROCESSES
314
SESSION: JUNE 2023
DURATION: 3 HOURS
PAPER: THEORY
MARKS: 100
EXAMINER(S)
MODERATOR:
SECOND OPPORTUNITY QUESTION PAPER
Dr Clement Kwasi Owusu
Prof. Godfrey Dzinomwa
INSTRUCTIONS
5. Answer all questions.
6. Read all the questions carefully before answering.
7. Marks for each question are indicated at the end of each question.
8. Please ensure that your writing is legible, neat and presentable.
PERMISSIBLE MATERIALS
3. Examination paper.
4. Non-programmable calculator.
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Question 1
(31 marks)
a. Mention 3 differences between cone crusher and gyratory crusher (9 marks)
b. An alluvial ore containing Gold (SG 19.0) and Quartz (SG 2.65) is to be
separated by Knelson concenh·ator. If the SG and viscosity of water are 1 and
0.00lPas respectively, discuss whether the selected density-based process is
appropriate
(10 marks)
c. A plant is being fed with metallic ore assaying 2.5 g/ t Au, producing a
concenh·ate product assaying 65 g/ t Au and tailings assaying 0.21 g/ t Au.
What is the recovery of Au, emichment ratio and ratio of concenh·ation? (12
marks)
Question 2
(36 marks)
a. Explain the significance of the contact angle between mineral particles being
floated and air bubbles in water. How does the addition of collectors affect the
contact angle?
(8 marks)
b. After blending at the ROM pad, it was estimated that the feed rate of pyrite and
quartz to a continuous flotation circuit were 8 t/h and 81 t/h respectively. If a
single cell in the bank of flotation cells gives pyrite and quartz recoveries of
35% and 2.5% respectively, at a residence time of 5 minutes
z. Determine the total recoveries of each mineral for a bank of 10 cells of
the same size and design
(12 marks)
zz. Estimate the tom1ages of quartz and pyrite in the concenh·ate? (8 marks)
c. Explain why conveyor belts used in the mining indush·ies are always equipped
with pull wires and underspeed sensors.
(8 marks)
Question 3
(33 marks)
a. Discuss briefly how separation of magnetic material from diamagnetic material
is achieved by the drum separator
(6 marks)
b. A plant h·eats an ore containing Pyrite (FeS2),Arsenopyrite (FeAsS) and Bornite
(CusFeS4). After ore upgrading and analysis, the Arsenic (As), Copper (Cu) and
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r
Iron (Fe) concenh·ation in the concenh·ate were 21.6%, 42.5% and 73.3%
respectively. What is the concenh·ation of pyrite, arsenopyrite, chalcopyrite in
the concenh·ate? (Molar masses of As, Cu, Fe and S are 74.92 g/mol, 63.55
g/mol, 55.85 g/mol and 32.07 g/mol respectively)
(12 marks)
c. An ore after mineralogical studies was found to contain mixtures of minerals
as shown below with their properties. As a consultant, propose a suitable
flowsheet for recovering Tantalite and Zircon from the mineral mixtures.
Also, give reasons for the selection of equipment that you would use to separate
all the minerals of interest.
(15 marks)
Mineral
Quartz
Talc
Tantalite
Zircon
Rutile
Composition
Si02
Mg3Sk014(0H)2
(Fe,Mn)(Ta,
Nb)206
ZrSi04
Ti02
S.G
Magnetic
response
2.65
None
2.75
None
6.2- Paramagneti
8.2
C
4.7
None
5.6
None
Electrostatic
response
None
None
Conductive
None
Conductive
THIS QUESTION PAPER CONSISTS OF 3 PAGES (Including this front page)
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