– MINE 292 – 2014 Laboratory Manual Introduction to Mineral Processing

Laboratory Manual – MINE 292 – 2014
Introduction to Mineral Processing
Safety in the Lab
Working with ores, machines and chemicals can be dangerous if proper procedures are not
followed. The most dangerous types of equipment are facilities with moving parts. Fingers and
loose hair can get caught in rotating shafts and serious injury may result. Some of the
chemicals used in the lab are considered toxic and great care must be taken in mixing these
chemicals and avoiding contact with skin or breathing in emissions.
The following requirements are mandatory when participating in the MINE292 labs:
1. All students are expected to wear a white lab coat and keep the front buttoned up.
2. All students are expected to use a face mask when working in the sample preparation room
and the screening laboratory to prevent inhalation of dust emitted from the ore.
3. All students are expected to wear long sleeve shirts, long pants, and shoes when working
in the lab. If you are assigned to work with the Rolls Crusher and/or to prepare samples in
the crushing room, you must wear a hard hat and steel-toed safety shoes.
4. At all times in the CMP Lab, everyone is expected to wear safety glasses. If you currently
wear glasses, these may be OK depending on their size. However, there are safety glasses
that fit over normal glasses and provide the side protection lacking with normal glasses.
5. If you have long hair, it must be covered with a scarf or other head gear.
6. No eating or drinking is permitted anywhere in the CMP Laboratory.
7. When mixing known toxic chemicals, it must be done within a fume hood.
8. When adding reagents to a flotation cell or to a grinding mill, do not pipette by mouth,
always use an air bulb or a hypodermic needle.
9. When taking samples to the drying oven, take care not to spill material on the floor.
10. Take care when removing containers from the drying ovens – the temperature is hot and
you may burn yourself.
11. Make sure all samples are properly labeled with the date, the sample name, the weight of
sample, the required assays, and your own name and course.
12. After finishing your work in the lab, you are required to clean up the table-tops and put all
equipment and supplies into their respective drawer.
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13. When doing grinding tests, make sure to not catch clothing or hair in the rotating mill.
14. When cleaning out a sample at the end of a grind test, pour all material into a pail and wash
out the mill. Wash each rod individually into the pail. Be careful not to add too much water
in order to avoid having to dewater before the flotation test.
15. When using the Pressure Filter, take care not to attempt to remove the sealed metal topplate without releasing the air pressure.
16. When using the Pressure Filter, make sure there is sufficient filter cloth on the bottom of the
filter so it properly seals and doesn't leak during operation.
17. When recovering material from the filter at the end of the test, make sure all of the material
is removed from the inner surface of the filter cylinder.
18. When using the Electrostatic Separator, be extremely careful to ground out the rotating
drum after shutting off the power. The voltage can be as high as 40kV but the charge in mA
is low, so danger is minimized, but should not be taken lightly. The unit should not be run at
an electricity level that generates sparks between the corona coil and the drum.
19. All horseplay in the lab is forbidden and students found to be participating in such activities
will be banned from the lab for the remaining term.
20. Never leave the lab without making it cleaner than when you arrived. Any student found
leaving a mess behind will be banned from future participation in the labs.
21. If you see anything that looks dangerous or if you see someone acting in a dangerous
manner, you must speak up. Safety is your personal responsibility for both yourself and
your workmates.
22. Ask the Technician or TAs for help whenever you are uncertain about the activities in which
you are participating.
23. Because the sizes of each group are large, please ensure that all members of the group
see what is happening and participate in the activities.
24. Each group performs a different experiment as listed in the lab schedule. The 1st and 2nd
persons in the list act as Group Leader and Seconder respectively for Lab 1. It is their
responsibility to see all activities are performed in a responsible and timely fashion and all
data collected. The 2nd and 3rd persons on the list are Group Leader and Seconder for lab
2; the third and fourth persons for lab 3; the 4th and the 5th persons for lab 4 and the 5th and
6th persons for lab 5. The seventh person will assist with the final lab organization.
25. Lab reports are due two weeks after the lab is performed. The write-up is to be done
collectively. Lab write-ups should follow the outline on the attached sheet. Write-ups should
be brief – no more than 5 pages. Use diagrams where appropriate and tables for all data.
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Laboratory Reports for MINE 292
One report per group per lab is required. The Group Leader and Seconder are responsible for
organizing the laboratory activities as well as the write-up each lab. Lab reports are due two
weeks after performing the lab.
Outline
Summary (one paragraph)
Introduction/Background
Procedure
Results
Discussion
Answers to questions
Conclusions
References
Maximum Number of Pages = 5.
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A1
Betaina, Fouad
Dodds, Emma
Jiang, Jiaqi
Mavety, Patrick
Rektor, Melissa
Zhang, Ran
B1
Chen, Zehan
Hansen, Morgan
Khanna, Prithvi
Nazari, Rojin
Wildsmith, Simon
Zwingenberger, Gert
MINE 292 Laboratory Groups
A2
A3
A4
Bradley, Trevor
Carson, Nathalie
Chan, Chun Yeung
Eidelof-Leighton, Erik Gallant, Charles
Gumboc, William
Johnson, Quinn
Kam, Gregory
Kao, Douglas
McKay, James
McLellan, Mark
Murat, Sanzhar
Sirotic, Mario
Tu, Duke
Tyab, Aron
De Wet, Ingemar
A5
Chan, Victoria
Hall, Jerry
Kelly, Davis
Murray, Glen
Weekse, Precious
B2
Cheng, Kevin
Heieis, Adian
Kiselbach, Dylan
Peddie,Logan
Willick, Greg
B5
Dick, Robert
Hua, Michael
Lu, Cathy
Qu, Tom
Yoon, Nawoong
B3
Correa Avelar, Barbara
Hengemuhle, Ian
Ladyman, Jon
Prost, Andrew
Wu, Aiden
B4
Dagget, Hayden
Ho, Ray
Leigh, Rob
Pudar, Marko
Xu, Bo
Laboratory Schedule
Group
A1
A2
A3
Tutorial Schedule
A4
A5
Group
A1
A2
A3
A4
A5
Lab. 1
Jan-23 Apr-03 Mar-20 Feb-27 Feb-06
Tut. 2
Jan-16 Mar-27 Mar-06 Feb-13 Jan-30
Lab. 2
Feb-06 Jan-23 Apr-03 Mar-20 Feb-27
Tut. 3
Jan-30 Jan-16 Mar-27 Mar-06 Feb-13
Lab. 3
Feb-27 Feb-06 Jan-23 Apr-03 Mar-20
Tut. 4
Feb-13 Jan-30 Jan-16 Mar-27 Mar-06
Lab. 4
Mar-20 Feb-27 Feb-06 Jan-23 Apr-03
Tut. 5
Mar-06 Feb-13 Jan-30 Jan-16 Mar-27
Lab. 5
Apr-03 Mar-20 Feb-27 Feb-06 Jan-23
Tut. 6
Mar-27 Mar-06 Feb-13 Jan-30 Jan-16
Group
B1
B2
B3
B4
B5
Group
B1
B2
B3
B4
B5
Lab. 1
Jan-16 Mar-27 Mar-06 Feb-13 Jan-30
Tut. 2
Jan-23 Apr-03 Mar-20 Feb-27 Feb-06
Lab. 2
Jan-30 Jan-16 Mar-27 Mar-06 Feb-13
Tut. 3
Feb-06 Jan-23 Apr-03 Mar-20 Feb-27
Lab. 3
Feb-13 Jan-30 Jan-16 Mar-27 Mar-06
Tut. 4
Feb-27 Feb-06 Jan-23 Apr-03 Mar-20
Lab. 4
Mar-06 Feb-13 Jan-30 Jan-16 Mar-27
Tut. 5
Mar-20 Feb-27 Feb-06 Jan-23 Apr-03
Lab. 5
Mar-27 Mar-06 Feb-13 Jan-30 Jan-16
Tut. 6
Apr-03 Mar-20 Feb-27 Feb-06 Jan-23
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Laboratory Procedure – MINE 292
Introduction to Mineral Processing
LAB 1. Grinding and Particle Size
A 1 kg sample of an ore is available for grinding test work. The sample is to be ground
for a particular grind time in a rod mill with a 20 kg rod charge at 65 %solids. Grind
times are 5, 10, and 15 minutes duration as advised by the lab instructor. Each week
will select a different grind time.
After grinding each sample, transfer it into a bucket and then filter the pulp using the
pressure filter.
Dry the sample in the drying oven for 1 hour. (Instead of drying the samples, the lab
instructor may ask you to perform a wet screen of the products).
When dry, place 75 grams of the sample onto a screen deck and run the deck on the
Ro-Tap machine for 20 minutes duration. The screen deck will be made-up of the
following screen sizes:
28 mesh screen
35 mesh screen
65 mesh screen
150 mesh screen
200 mesh screen
270 mesh screen
Pan
Weigh each size fraction and record the weights in a table.
Expand the table in a spreadsheet to report the weight% in each fraction and the
cumulative weight% passing and retained on each size.
Graph the data and establish the d80 particle size as well as the d50 size.
Assuming the feed size d80 is 1,240 microns, what reduction ratio was achieved in this
grinding test?
Assuming the feed size is 12,700 microns and the required grind is 80% passing 105
microns, what power must be installed on a mill to process 250 tph, if the Work Index is
13.2 kWh/t?
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Laboratory Procedure – MINE 292
Introduction to Mineral Processing
LAB 2 – Physical Separation (shaking table)
A 1-kg sample of an ore containing copper ore and beach sand is available for
separation using a shaking table.
Mix the ore with water to achieve a pulp density of 30%solids.
Turn on the shaking table and adjust the water flow so a thin film of water flows
across the table. Adjust the table to an angle of about 0.25 degrees with an
eccentric throw of about 2-3 cm.
Slowly feed the slurry into the feed box so the ore particles flow out into the table
and begin to flow both across the table and along the riffles.
Adjust the concentrate splitter to cut a high-grade concentrate and adjust the tailings
splitter to achieve a low-grade tailing product.
Continue the test until all the feed material has left the table. Collect the three
products – concentrate, middlings, and tailings. Filter these products in a pressure
filter press and examine all products under a microscope. Weigh the three products
and calculate the solids weight assuming a 10% weight of water in each product.
Estimate the quantity of pyrite by volume in each sample. Convert the %volume to a
%weight and prepare a mass balance of the test reporting the weight yield and the
%recovery of pyrite and %recovery of quartz.
Questions:
1. Did you observe a particle size effect on the separation of pyrite and quartz on
the shaking table? If so, describe the effect and provide an explanation of how
the riffles act to segregate fine and coarse particle?
2.
Based on the observed productivity, what general conclusion can you make
about the use of shaking tables for conducting gravity-separation of an ore with
respect to the size of plant? Assuming each commercial table is 10x the size of
the laboratory model, and that each table can process about 1.5 tph of ore,
layout a plant to process 1,000 tpd of an ore. Assume cleaning tables are
unnecessary.
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Laboratory Procedure – MINE 292
Introduction to Mineral Processing
LAB 3. – Physical Separation (electrostatic)
A 1-kg sample of a galena-quartz ore is available for processing by electrostatic
separation. The CARPCO high-intensity electrostatic separator will be used.
Place a sample into the feed bin and turn on the rotor. Adjust the speed to about 50
rpm. Adjust the electric field strength to about 32,000 kV.
Open the feed port and allow material to flow across the drum and through the electric
field collecting three products – concentrate, middlings, and tailings.
Weight all products and estimate the galena content in each product.
Redo several tests under different conditions and report the results in metallurgical
balance tables that give %Yield of total weight and %Recovery of lead.
What productivity was achieved in this test in terms of feed tonnage per unit length of
the roll?
What length of roll would be required in metres to process 5 tph of material?
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Laboratory Procedure – MINE 292
Introduction to Mineral Processing
LAB 4. Flotation
Flotation is the most widely used method to separate ores because of its high degree of
selectivity and its ability to deal with fine ores.
A 1-kg sample of a copper ore is available for flotation and has been ground to a
suitable degree of fineness. Place the ore into a 2-L flotation cell and add water
sufficient to yield a density of 25%solids. Adjust the level of the pulp to about 3 cm
below the lip.
Turn on the impeller to about 1800 rpm. Keep the air valve closed.
Add 50 g/t of Potassium Amyl Xanthate to the slurry and condition the pulp for 5
minutes. Turn on the air and observe the froth. Record your observations.
Turn off the air and add 4 drops of Pine Oil into the cell. Condition the pulp for 1 minute
and then turn on the air. Observe the froth once more and record any differences in the
froth characteristics.
Pull off the froth into a flotation pan using a paddle - maintain a consistent stroke and
add water using a wash bottle to maintain the forth height.
Change the pans at the following time intervals – 0.5, 1.0, 1.0, 3.0 minutes.
If the froth still appears to contain significant copper mineralization, then add an
additional 2 minutes of flotation. If the froth dies out before the end of the test, add an
additional 2 drops of Pine Oil. Filter the tailings in a Pressure Filter press.
Weight all samples after drying and bag the samples for assay.
After receiving the assays, use the weights to perform a metallurgical balance to report
a grade/recovery curve. Apply the following smelter contract and calculate the optimum
point on the grade/recovery curve:
Pay $4.00 per pound of contained copper after deducting 1% from the dry
assay. Charge $200 per tonne of concentrate for smelting and transport.
Deduct $0.20 per pound of smelter recovered copper for refining and
transport.
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Laboratory Procedure – MINE 292
Introduction to Mineral Processing
LAB 5. Thickening Tests
Prepare four 1-L graduated cylinders for test work. Place 50g of fine silica into each
cylinder and fill to the 1-L mark.
Agitate and well-mix the contents in each cylinder. Label the cylinders from 1 to 4.
Place the following amounts of flocculant into each cylinder and gently mix for 5 min.:
Cylinder 1 = 0.005%
Cylinder 2 = 0.05%
Cylinder 3 = 0.10%
Cylinder 4 = 0.20 %
Start the stop watch when agitation is finished and record the mud level in each
cylinder at the following time intervals: 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 20, 40, 60, minutes
and after 24 hours.
Plot a graph of the results allowing you to obtain the settling rate. Plot the settling rate
as a function of flocculant addition.
Use the results to design a thickener to treat 75,000 tonnes of dry solids per day at a
feed density of 45 %solids and an underflow density of 65 %solids which will also
produce clear water in the overflow. Assume the S.G. of the solids is 2.73.