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What is the advantage of hydrometallurgy compared to pyrometallurgy and electrometallurgy?
MINE 290
Introduction to Mining and Mineral Processing
Final Examination
Time Limit: 3 hours December 5, 2003
MILLING QUESTIONS
(76 marks - all questions of equal value)
1. A mill processes 12,500 tonnes of wet ore per day with a relatively low moisture content
of 1.5 %H
2
0. The feed grade of dry ore is 2.5 %Pb and 4.8 %Zn. The ore is processed in a
differential flotation circuit in which lead is recovered in the first stage to a Pb concentrate
at a grade of 67.5 %Pb leaving a Pb circuit tailing containing 0.42 %Pb and 4.75 %Zn.
This latter material is fed to a zinc flotation circuit producing a Zn concentrate of 53.6
%Zn and a final tailing containing 0.31 %Zn and 0.26 %Pb.
a.
What is the percent recovery of Pb to the Pb concentrate and the percent recovery of Zn
to the Zn concentrate?
b.
What is the grade of Pb in the Zn concentrate and the grade of Zn in the Pb concentrate?
c.
Describe the types of chemicals that would be added to the Pb circuit feed and to the Zn
circuit feed and give their function in the flotation circuit.
2. Tailing disposal at a mine site is one of the major expenses involved in both building a
mine and then in operating the facility. Problems associated with environmental protection
and geotechnical aspects are extremely important if a long-term viable operation is to be
achieved.
a.
Discuss tailing disposal practices with respect to four different methods of disposal.
Provide examples of where each method might be used and why its use might be
preferred over the other methods?
b.
What is ARD and why is it such a ubiquitous
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and important problem in mining?
c.
Discuss water use in milling with respect to using fresh water and with respect to using
recycle water. What aspects of a mill affect the use of recycle water? How can these
effects be minimized?
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Ubiquitous means existing or being everywhere at the same time; constantly encountered; widespread.
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3.
A ore with a work index of 12.5 kWhr/t is ground in a lab ball mill for 10 minutes using a
20,125 gram charge of half-inch stainless steel balls. The 80 % passing size of the ore
was initially 4 mm while the 80 % passing size after grinding was 93 microns. A second
sample of a similar ore was subjected to the identical procedure. The sample had an 80 %
passing size of 3 mm and the product showed an 80 % passing size of 107 microns.
a.
What is the work index of this second ore sample?
b.
What is a SAG mill and why has this unit operation become so popular over the past 25
years or so? Is this popularity deserved and what might suggest that SAG milling is
overblown as a legitimate process?
c.
Discuss the differences and similarities between liberation and "grind size".
4.
Sustainable Mining is a term used to describe how a mining company and industry
designs, operates, manages and closes operations around the world in the 21
st
Century.
The concept of sustainable mining accounts for technical, economic, environmental, and
socio-political aspects of operating a mine in a particular region or jurisdiction.
a.
From the viewpoint of the principal components of Mining and Milling (Mining,
Liberation, Separation, Extraction), discuss how each of these components have changed
as the social and political aspects take on a relatively more-important position in the
decision-making involved in running a mining company. Give at least one example of
how the socio-political aspects of a situation impact on technical decisions in Mining, in
Liberation, in Separation and in Extraction.
b.
Connect each of the terms at the left with its most appropriate match on the right:
i. locked particles a. middlings
ii. gangue j. copper sulfate
iii. hydrophilic g. pH modifier
iv. carbon-in-leach i. depression
v. head grade e. water-avid
vi. riffles b. waste minerals
vii. soda ash h. gravity separation
vii.jig c. assay of mill feed
ix.critcal pH d. gold recovery
x.activator f. shaking table
c. Why is hydrometallurgical processing becoming a more important extraction process in
place of pyrometallurgical processing? Give at least three reasons.
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MINING QUESTION
(25 marks)
5. For the mineral deposit described below,
prepare
a detailed outline of the steps involved
in bringing this prospect (including the major studies required) into a producing mine (5
marks
).
Select
the mining method which would be best suited, most economical, and
safest for the conditions given (5 marks
),
defending
your choice briefly (5 marks
), and
citing
the main advantages and disadvantages of the method (5 marks
).
Identify
the cycle
of operations and the major equipment pieces required for supporting your selected
mining method (5 marks
). Total 25 marks.
Design conditions are as follows:
Deposit - a) chalcocite/chalcopyrite ore mineral disseminated in a quartz porphyry
intrusive, average grade 0.5% Cu, fairly uniform ore distribution.
b) massive irregular deposit, reserves estimated at 100 millions tonnes
extending to 350m below ground surface, average depth of covering
overburden is 25m.
c) ore compressive strength set at 85 MPa, frequent joints.
d) host rock is a schist with a compressive strength of 55 MPa, fractured
and with distinguishable boundary contact with the ore.
Topography - Desert and low mountain ridges, elevation 1370 metres.
Climate - Arid, mean annual rainfall 250 mm.
Ore Production Rate - 20,000 tpd over a 20-year mine life.
Metal Value - $2.00 US/kg.
What else can I help you with?
It is anything that a firm does especially well compared to rival firms?
competitive advantage
Does a country have a comparative advantage in the production of some good?
Yes, a country has a comparative advantage in the production of a good when it can produce that good at a lower opportunity cost compared to other countries.
In which country does a comparative advantage in the production of a good exist if it can?
A comparative advantage in the production of a good exists in a country when it can produce that good at a lower opportunity cost compared to other countries.
The concept of competitive advantage in business organizations?
A Competitive advantage describes the ability of a firm to be better at something than all other firms in that industry. This advantage allows the firm to differentiate their product/themselves by being 'better' than their competition. Not to be confused with comperative advantage, which focuses on a firms ability to be better at something COMPARED to another firm.
What are the changes in the UK's absolute and comparative advantage industries compared with other countries Take an example.?
Type your answer here... 不知道哦
What are some uses and advantages of electrometallurgy?
Electrometallurgy is used in the production of various metals like aluminum, magnesium, and titanium. It offers advantages such as high purity of the produced metal, efficient energy consumption compared to traditional methods, and the ability to recycle and reclaim metals from scrap materials.
What is the advantage of presenting data in table form?
Depends on advantage compared to what. There may not be any advantage compared with representing data in graph form.
What is cumulative advantage?
A cumulative advantage is the totality of the advantage that the business has compared to competitors. This includes employees, intellectual property, and business processes.
What is the advantage and disadvantege of milling cutters compared to single point cutter?
advantage and disadvantage of milling cutter
What's the main advantage of a diesel train?
The advantage of the diesel train is that it is not expensive to run as compared to the electric train.
What are the advantages of the bike?
As compared to what? The advantage of an exercise bike when compared to a regular bike is that you can ride and get your exercise w/o having to worry about weather and traffic. The advantage when compared to a treadmill is less impact, takes less place and maybe you prefer cycling over running.
Major advantage in cpp compared to c?
The major advantage of C++ over C is the Object Oriented Programming compatibility in C++.
What is one advantage of a debit card compared to a credit card?
One advantage of a debit card compared to a credit cards is that with debit card you will not be heavily indebted because your purchases are directly charged to your checking account.
What is the advantage of using checks compared to other forms of payment?
One advantage of using checks compared to other forms of payment is that they provide a paper trail of transactions, making it easier to track and record expenses.
It is anything that a firm does especially well compared to rival firms?
competitive advantage
What advantage do birds have over other species when their food supply changes?
they are cappable to migrate which is an advantage when compared with starvation of humans depending on agriculture in Africa
The advantage of dpsk over coherent psk?
dpsk has lesser bw compared to psk
