{[ promptMessage ]}

Bookmark it

{[ promptMessage ]}

exm301ie20071

exm301ie20071 - MURDOCH UNIVERSITY ‘ v PERTH WESTERN...

This preview shows pages 1–4. Sign up to view the full content.

This preview has intentionally blurred sections. Sign up to view the full version.

View Full Document

This preview has intentionally blurred sections. Sign up to view the full version.

View Full Document
This is the end of the preview. Sign up to access the rest of the document.

Unformatted text preview: MURDOCH UNIVERSITY ‘ v PERTH, WESTERN AUSTRALIA Examinations - Semester 1, 2007 nit EXM301 MINERAL PROCESSING I ExamType - Internal & External Time Allowed 3 hours plus 10 minutes reading time INSTRUCTIONS ANSWER ONLY FIVE QUESTIONS EXAMINATION AIDS ALLOWED Provided by the Universiﬂ GRAPH PAPER (A4 1MM) GRAPH PAPER (LOG-LOG) Provided by the Candidate CLOSED BOOK EXAMINATION CALCULATOR PERMITTED (NOT GRAPHICS) ANSWER ONLY FIVE QUESTIONS ALL QUESTIONS CARRY EQUAL MARKS AS INDICATED . How would you determine the size distribution of a SAG mill feed stream that is fed by a conveyor belt. (5 marks) . Brieﬂy describe the requirements of a sample cutter that may be used to sample a hydrocyclone underﬂow stream. (5 marks) . The feed to a copper ﬂotation circuit is prepared using a standard SABC comminution circuit. A 5kg sample of ore is taken by sampling the SAG mill discharge with a top size of 3mm, so that the assay error is kept to within :h 0.2% Cu @ 95% level of conﬁdence. What would be the assay error if a sample of 1.0 kg is taken ﬁom the ﬂotation circuit feed which has a top size of 150p? Note: liberation factor = (liberation size/particle size)'/2 (10 marks) A sample of an ore was batch ground in a laboratory mill. The results of the size analysis of the ground product are given in the table below. TABLE 1: Sieve Analysis Data Size (microns) Cum.Weight (%) Passmg 1600 . Evaluate the parameters of the Gate-Gaudin Schuhmann plot of the above product. (10 marks) . Hence calculate the amount of ﬁnes below 10 microns in the product. (5 marks) Determine the sphericity of cubic particle of side 2mm. (5 marks) Describe the characteristic features of a Rod mill, Ball mill and a SAG mill. Highlight any differences in their design and/or operation. (6 marks) . What are “seats” and explain how you would deal with seats in a comminution circuit? (4 marks) What are the main beneﬁts of having a circulating load in a grinding circuit compared to an open circuit operation? (4 marks) . Brieﬂy describe the following: (i) Critical speed of a tumbling mill. (2 marks) (ii) Grindability of an ore. (2 marks) (iii) Mill charge. (2 marks) Sketch a typical Grade/Recovery plot that represents a spiral concentrator performance treating a beach sand that produces a heavy mineral concentrate and a tailing. Give two measures of efﬁciency that can be used to enumerate the efﬁciency of the separation process at a given operating point. Discuss their limitations. (8 marks) . The feed to a gravity concentrator contains 10% heavy mineral. The concentrate assays 30% heavy mineral and the tailings assay 1.5% heavy mineral. Determine: (i) The mass % of the feed recovered in the concentrate. (6 marks) (ii) The separation efﬁciency of the separation. (6 marks) Describe the working of a spiral classiﬁer or a hydrocyclone. (3 marks) . Explain why the performance curve of a hydrocyclone does not pass through the origin. Show how it may be modiﬁed to determine a plot that represents the “machine characteristics” of the hydrocyclone. (8 marks) The reduced performance curve of a jig is shown in Figure 1. If the jig operates at a cut speciﬁc gravity of 1.6, determine the operating performance curve of the jig. Also estimate the probable error and the imperfection. (9 marks) Discuss the factors affecting the performance of an industrial screen. (6 marks) . What are washability curves used in gravity concentration circuit design? Sketch typical curves and illustrate how they are used. (8 marks) Suggest a ﬂow sheet to process a beach sand mineral deposit comprising of the following minerals: Ilmenite, Rutile, Zircon, Monazite and Silica gangue. (6 marks) 5! Cum Wt. % to Floats Figure 1 - 05- Reduced Performance curve of Jig 1 00 90 80 7O 6O 50 40 30 20 10 0 T71 _J___ M .L..._ l _ I— ...w... _._._l L—eﬁe a— 0.5 0.6 0.7 0.8 0.9 1 ____'_ 1.1 1.2 1.3 1.4 1.5 1.6 1.7 1.8 1.9 ReducedSG ******** END OF PAPER ******** ...
View Full Document

{[ snackBarMessage ]}

What students are saying

• As a current student on this bumpy collegiate pathway, I stumbled upon Course Hero, where I can find study resources for nearly all my courses, get online help from tutors 24/7, and even share my old projects, papers, and lecture notes with other students.

Kiran Temple University Fox School of Business ‘17, Course Hero Intern

• I cannot even describe how much Course Hero helped me this summer. It’s truly become something I can always rely on and help me. In the end, I was not only able to survive summer classes, but I was able to thrive thanks to Course Hero.

Dana University of Pennsylvania ‘17, Course Hero Intern

• The ability to access any university’s resources through Course Hero proved invaluable in my case. I was behind on Tulane coursework and actually used UCLA’s materials to help me move forward and get everything together on time.

Jill Tulane University ‘16, Course Hero Intern