Report Buzwagi

8/4/2019 Report Buzwagi

1/21

ACKNOWLEDGEMENT

I sincerely give my special thanks to our almighty God for being so good and keeping me

healthy.

Special thanks should also go to my project supervisor Eng. Paul Gongo for his wonderful

assistance to the completion of this project.

I also give extraordinary thanks to the management of the Buzwagi Gold mine for the provision

of this wonderful opportunity of providing me a placement of conducting my final year project. I

explicitly acknowledge the unlimited support and enthusiastic cooperation which I received from

the Mining Manager Mr. Neil Colobourne, the senior Engineer Mr. Godfrey Ayisi, Engineer

Onesphory Gebra and Engineer Sebastian Joseph.

Lastly I would like to be grateful to my family and friends for their support.


2/21


3/21

DEFINITION OF TERMS

Cycle time is a Time used by a machine to complete a single unit of operation.

Density is the ratio of the mass of a substance to its volume, and it can be calculated by dividing

the mass by the volume.

Digital imaging is a method of making images without the use of conventional photographic

film. Instead, a machine called scanner records visual information and converts it into a code of

ones and zeroes that a computer can read.

Fleet is a number of loading and hauling equipment working and managed as single unit

Mine dispatch is a center of information between the machines and equipment operation,

performance and mine production.

Payload is the quantity of load that a truck, or other vehicle that can carry, often expressed in

terms of weight or volume.

Software is a computer program; instructions that cause the hardware or the machines to do

work.

Stockpile is a collection and storage of large amounts of material.

Surveying is amathematical science used to determine and delineate the form, extent, and

position of features on or beneath the surface of the earth for control purposes.

Swell factor is the percentage increase of material volume when are removed from in situ.

Terrain is a ground or a piece of land seen in terms of its surface features or general physical

character, especially for crossing it.

Truck factor is percentage of the rated capacity that a truck is assigned to carry at a particular

time and particular conditions.


4/21

ABBREVIATIONS

3DThree Dimension

BCMBank Cubic Meter

DEMDigital Elevation Model

DGMDigital Ground ModelDGPSDifferential Global Positioning System

DHMDigital Height Model

DTEMDigital Terrain Elevation Model

DTMDigital Terrain Model

EDMElectronic Digital Measurement

GCPGround Control Point

GNSSGlobal navigation satellite system

GPSGlobal Positioning System

HEXHydraulic excavator

ILRIS- Intelligent Laser Ranging & Imaging System

JDSJigsaw Dispatching SystemKPIKey Performance Indicator

LCDLiquid Crystal Display

LCMLoose Cubic Meter

MHzMegahertz

OHTOff- Highway Truck

SAESociety of Automotive Engineers

TINTriangulated Irregular Network

UHFUltra High Frequency

VHFVery high Frequency

WLWheel Loader


5/21

1.0 INTRODUCTION

1.1 LOCATION AND ACCESSIBILITY:

The Buzwagi Project is located in Kahama District, Shinyanga region, in northwest Tanzania.

The mine lies on the divide defined by boundaries of the Hindagi river watershed, which drains

toward Lake Victoria, and the Kagozi river watershed, which drains toward Lake Tanganyika.

The mine is located approximately 6 km east of Kahama town along the tarmac road, and

approximately 100 km west of the town of Shinyanga.

Figure 1 : A map showing the location of Buzwagi mine.The Buzwagi open pit is located on land for which Pangea Mineral Limited (PML) acquired a

prospecting license in 1992. Between 1995 and 2000, this land was optioned to and explored by

Anmercosa Service (East Africa) Limited. In 2003, Pangea initiated its own exploration

program. Because of this exploration program, a design was made in 2004 to move the project

into development phase and in 2008 started the mining operations.

1.2 GEOLOGY AND RESERVES.

Buzwagi is hosted in the Nzega Belt, which consists of the lower portion of the Nyanzian

system. This belt is composed of basalts and intermediate volcanic intruded by granitoid masses.

The regional structure elements are dominated by a deep seated structural trend referred to as the

Nzega shear.


6/21

This shear comprises numerous second and third order structures in which the Buzwagi deposit

is likely hosted in one of these supplementary shears. Buzwagi mine operates a single open pit

mine; the size of the pit is approximately 0.9 km wide and 1.2 km length. Production began in

may 2009, expecting to generate 250 thousand to 260 thousand oz of gold per year in its first full

five years of operation. Proven and probable reserves at Buzwagi are 3.3 million oz of gold and

79 million kg (175 million lb) of copper. The expected mine life based upon proven and probable

reserves is about 15 years. With continued exploration indicating additional reserves, it is

anticipated that the life of mine may be extended.


7/21

PROJECT TITLE:

A COMPARISON OF TONS MINED ON A MONTHLY BASIS MEASURED AGAINST

THE TONS REPORTED FROM SURVEY VOLUMES AT BUZWAGI GOLD MINE

2.0 PROBLEM STATEMENT

In mining industry, it is vital to get correct production figures as they are presented before

stakeholders and different shareholders. At Buzwagi mine, production figures are tracked and

recorded on daily basis by using a jigsaw dispatching system and at the end of the month are

compared to the monthly surveyed volumes.

A big difference has been noticed to exist between the production reports and the survey reports

whereas figures reported by dispatcher are higher than those reported by the surveyors.

2.1 MAIN OBJECTIVE

To investigate the causes of the variation and the best way to ensure the two reports are

presenting the same figures.

2.2 SPECIFIC OBJECTIVES

To determine the effectiveness of the jigsaw dispatching system

To review the material density and the swell factor

To compare the tons from production against surveyed volumes

2.3 SCOPE OF THE STUDY

The project will deal with blasted and mined material from the pit for the purpose of mine

production at Buzwagi mine.


8/21

5.0 DATA COLLECTION

Data were collected at buzwagi mine site from the pit and technical service office. Data collected

were the following;

5.1 Survey volumesSurveyed volumes of material mined from the pit for the period of nine months from May

2010 to March 2011 were collected from the survey section of the technical service

department at buzwagi mine. The data were extracted from the spreadsheet saved in the

computer.

5.2 Dispatch volumesTwo types of data were collected for the volumes of material mined and recorded at

dispatch office. The first data was the data captured into the computer system directly by

the jigsaw dispatching software and the second data was the one recorded in spreadsheet

by the dispatcher, this is the data obtained through a two way radio communication

between the dispatcher and the truck operators. The data collected was for nine months

from May 2010 to March 2011

5.3 Truck factorsEstablished truck factors for the nine months from May 2010 to March 2011 were

collected from the Dispatch Engineer office

5.4 Material densityInsitu and loose density of material was done in the Geology laboratory at Buzwagi mine

site and on the pit respectively. The insitu density was found by application of

Archimedes principle in the laboratory whereas the loose density was done using

standard measuring of volumes and masses of the samples of loose materials collected on

the pit. Sampling was done from different parts of the pit to have a good representative of

the entire pit.


9/21

5.4.1 Insitu density experiment

Equipments;

Digital weighing balance

Bucket of water

A rope

Procedures

i. A digital weighing balance was calibrated to zero reading

ii. A sample of insitu rock was measured on the digital weighing balance and its

weight was recorded as weight in air

iii. A sample was immersed full in water and its weight is measured on the digital

weigh balance, the weight was recorded as weight in wateriv. Density of a sample rock was calculated from the formula;

v. Procedures ( i-iv ) were repeated for all samples collected from different parts

of the pit.

5.4.2 Loose density

Equipments;

Mass balance

A 20cm x 20cm x 20cm can

Plastic bags

spade

Procedures

i. sample of blasted material was filled into the can using a spade

ii. the plastic bags were measured for their masses

iii. sample materials were taken from the can and filled into the plastic bag and

measured for their mass

iv. density was calculated using the formula;


10/21

v. Procedures (iiv) was repeated for different samples collected from different

parts of the pit.


11/21

6.0 DATA ANALYSIS

6.1 Effectiveness of Jigsaw dispatching systemAn analysis of the jigsaw dispatching system was done by comparing the total BCM captured by

the system with the dispatching information obtained through a two way radio communication.

The capturing of production data of the jigsaw dispatching system is not consistency with the

capturing of data using a two way communication between the dispatcher and the truck

operators. In most of the times it was found that the dispatch spreadsheet data were higher than

the jigsaw captured data, this was found to be caused by ineffectiveness of the signals

transmission from the transmission tower to the trucks. The problem is facilitated by the shape of

the pit where the deepest parts of the pit are obstacles to the signals transmission.

300,000.00

400,000.00

500,000.00

600,000.00

700,000.00

800,000.00

900,000.00

1,000,000.00

BCM'S

Months

DISPATCH SPREADSHEET BCM Vs JIGSAW BCM

DISPATCH BCM

JIGSAW CAPTURE


12/21

6.2 Comparison of production BCM against surveyed BCMThe total reported monthly production BCM were compared with the monthly reported survey

BCM and the chart () was obtained.

Of the eleven months of data collected, it shows that eight months presented higher production

BCM than surveyed BCM whereas three months presented higher survey BCM than production

BCM.

300,000.00

400,000.00

500,000.00

600,000.00

700,000.00

800,000.00

900,000.00

1,000,000.00

BCM

MONTHS

DISPATCH BCM Vs SURVEY BCM

DISPATCH BCM

SURVEY BCM


13/21

6.3 Material densities and percentage swellsInsitu densities and loose densities of materials from different locations of the pit were analyzed

to obtain chart and chart below.

Insitu densities of material vary from one location of the pit to another as indicated in the chartabove where the densities are 2.51t/m

3, 2.73t/m

3and 2.48t/m

3for stage1, stage2 and stage3

respectively. Average loose densities were found to vary in the same sense too. This is caused by

different rock types and layers found in Buzwagi pit.

Calculation of percentage swell

( )

2.51

2.73

2.48

1.60 1.621.49

0.00

0.50

1.00

1.50

2.00

2.50

3.00

1 2 3

DEN

SITIES

STAGES

INSITU AND LOOSE DENSITIES

INSITU

DENSITYLOOSE

DENSITY


14/21

Considering found densities of fresh rocks from experiment

insitudensity

loosedensity %swell

stg2 2.73 1.62 69

stg1 2.51 1.60 57

stg3 2.55 1.53 67

AVERAGE 2.595934972 1.584618056 64

Assumptions made

Mined blocks with known dimensions to produce insitu volumes (BCM) of 200, 300, 400, 500,

600, 700, 800 and 900.

Sample calculation;

Loose volume = insitu volume x % swell

= 200 x 1.64

= 328

Survey tons = insitu volume x insitu density

Production tons = loose volume x density


15/21

Applying average insitu density for survey and production tons;

AVERAGE

INSITU

DENSITY

SURVEY

BLOCK

VOLUME

LOOSE

VOLUME

SURVEY

TONS

PRODUCTION

TONS

%

INCREASE

2.59 200 328 519.19 851.47 642.59 300 492 778.78 1277.20 64

2.59 400 656 1038.37 1702.93 64

2.59 500 820 1297.97 2128.67 64

2.59 600 984 1557.56 2554.40 64

2.59 700 1148 1817.15 2980.13 64

2.59 800 1312 2076.75 3405.87 64

2.59 900 1476 2336.34 3831.60 64

Percentage increase from production to survey tons is equivalent to the average percentage swell

of material indicating that material swell has direct impact on tons comparisons. The approach is

not recommended because it applies only insitu density and affected by extreme density and

swell variations of material mined over a particular time.

0

500

1000

1500

2000

2500

3000

3500

4000

4500

1 2 3 4 5 6 7 8

TONS

MINED BLOCKS

SURVEY AND PRODUCTION TONS PROVIDED SAME INSITU DENSITY IS APPLIED

SURVEY TONS

PRODUCTION TONS


16/21

Applying averaged insitu and loose densities for surveyed and production tons respectively

INSITU

AVERAGE

DENSTY

LOOSE

AVERAGE

DENSITY

SURVEY

BLOCK

VOLUME

LOOSE

VOLUME

SURVEY

TONS

PRODUCTION

TONS

%

INCREASE2.59 1.58 200 328 519.18 519.75 0.10

2.59 1.58 300 492 778.78 779.63 0.10

2.59 1.58 400 656 1038.37 1039.51 0.10

2.59 1.58 500 820 1297.96 1299.39 0.10

2.59 1.58 600 984 1557.56 1559.26 0.10

2.59 1.58 700 1148 1817.15 1819.14 0.10

2.59 1.58 800 1312 2076.74 2079.02 0.10

2.59 1.58 900 1476 2336.34 2338.90 0.10

This is the best scenario that yields a difference of 0.1% between the production tons and the

surveyed tons

0

500

1000

1500

2000

2500

1 2 3 4 5 6 7 8

TONS

MINED BLOCKS

SURVEY AND PRODUCTION TONS PROVIDED INSITU AND LOOSE DENSITIES ARE

APPLIED

SURVEY TONS

PRODUCTION TONS


17/21

7.0 CONCLUSION

It has been concluded that the percentage swell of material is direct proportional to the difference

of the production tons and survey tons provided the same average insitu density is applied in

conversion of BCM to tons. The material with higher density difference between the insitu and

loose density will produce higher percentage swell of the material hence bigger variation of the

two ton figures and if the material has small difference of the two densities will have lower

percentage swell and hence lower variation of the two tons. In this case the swell factors must be

included in the conversion of BCM to tons.

However, it has been concluded that for the correlation purpose of the two ton figures, it is

necessary to consider the loose density in the determination of production tons for the fact that

the data considered in production are for loose materials. Doing so will eliminate the effect of

percentage swell of material.

8.0 RECOMMENDATION

It is recommended that in order to obtain true production tons, the swell factor of materials

should be considered in conversion of BCM to tons. The consideration can be achieved through

measuring of material densities before and after blast. The average of the densities should berecorded for the entire month so as to be used in the calculation of monthly mined tons.

It is further recommended that the densities to be recorded should be only taken from mined

blocks so as to obtain actual densities of mined materials with no inclusion of unmined materials.


18/21

9.0 REFERENCES

Bettina pflipsen, 2006, volume computation, a comparison of total station versus laser

scanner and different software, A masters thesis, University of Gavle, Switzerland.

H. Murat Yilmaz and Murat Yakar, computing of volume of excavation areas by digital

close range photogrammetry, The Arabian Journal for Science and Engineering, Volume

33, Number 1A, Aksaray University, Engineering Faculty Geodesy and Photogrammetry

Department, Aksaray, Turkey.

http//books.smenet.org/Surf_Min_2ndEd/sm-ch06-sc05-ss02-bod.cfm

http//www.answers.com/

JC Najor and PC Hagan, Mine production scheduling within capacity constraints, The

University of New South Wales (UNSW), Sydney

Karim Mleli, Fleet management study using Jigsaw dispatching system at Buzwagi gold

mine with the aim of improving productivity and operating performance, Field report,

2010, Buzwagi Gold Mine, Tanzania.

Kemp-Engineering survey and setting out services-page 1,

www.kempengineeringsurvey.co.uk

M. A. R. Cooper and S. Robson, "Theory of Close Range Photogrammetry", Close Range

Photogrammetry and Machine Vision, 1996, p. 9.

Modular Mining Systems. 2003, whttp://www.mmsi.com/modular/news, Company

News, Arizona,USA.

Osanloo, M. , Gholamnejad, J. and Karimi, B.(2008) 'Long-term open pit mine

production planning: a review of models and algorithms', International Journal of Mining,

Reclamation and Environment, 22: 1, 335, First published on: 02 July 2007

Wenco International Mining Systems. 2003, http://www.wencomine.com/products. asp,

Product Overview, Vancouver, Canada.

www.optech.ca/www.ilris-3d.com
http://www.kempengineeringsurvey.co.uk/http://www.kempengineeringsurvey.co.uk/http://www.optech.ca/www.ilris-3d.comhttp://www.optech.ca/www.ilris-3d.comhttp://www.optech.ca/www.ilris-3d.comhttp://www.kempengineeringsurvey.co.uk/


19/21

10. APPENDICES

Appendices 1: Monthly BCM recorded

DISPATCHBCM JIGSAW CAPTURED BCM

SURVEYED BCM

Mar-11 736,239.00 660,226.00

631,696

Feb-11 668,906.13 714,371.00

660,992

Jan-11 677,912.42 764,607.00

729,867

Dec-10 776,836.36 772,655.00

650,997

Nov-10 668,738.64 652,708.00

610,104

Oct-10 471,709.62 472,659.00

402,888

Sep-10 479,151.36 479,636.00

402,888

Aug-10 789,386.80 782,259.00

575,516

Jul-10 941,618.44 928,243.00

947,068

Jun-10 846,602.61 832,345.00

659,009

May-10 808,049.52 814,379.00

698,483

Appendices 2: Monthly truck factors

MONTH HD 1500 HD 785

April 2010 46 30

May 2010 45.36 29.16

June 2010 46.83 30.1

July 2010 44.86 28.84

August 2010 44.96 28.84

September 2010 44.96 28.84

October 2010 43.35 27.87

November 2010 43.88 28.21

December 2010 47.16 30.32

January 2011 44.62 28.68

February 2011 44.95 28.89

March 2011 43.0 28.0


20/21

Appendices 3: Insitu densities

STAGE 1 (FRESH ROCK)

WEIGHT IN AIR(g)WEIGHT INWATER(g) SPECIFIC GRAVITY

1 724 425 2.42

2 990 600 2.54

3 1036 646 2.66

4 1098 646 2.43

AVERAGE 2.51


1 653 380 2.39

2 763 509 3.003 716 460 2.80

4 466 296 2.74

AVERAGE 2.73


1 773 463 2.49

2 1224 760 2.64

3 1136 683 2.51

AVERAGE 2.55

STAGE 3

(TRANSITION

ROCK)

1 1296 694 2.15

2 1120 690 2.60

3 1170 694 2.46

2.41


21/21

Appendices 4: Loose densities


WEIGHT (Tons) VOLUME (Cubic meter) DENSITY (Tons/cubic meter)

1 0.01240 0.008 1.552 0.01165 0.008 1.46

3 0.01300 0.008 1.63

4 0.01430 0.008 1.79

AVERAGE 1.60

STAGE 2


1 0.0123 0.008 1.54

2 0.0141 0.008 1.763 0.0124 0.008 1.55

AVERAGE 1.62

STAGE 3 (Fresh)


1 0.012 0.008 1.5

2 0.011 0.008 1.38

3 0.0137 0.008 1.71

AVERAGE 1.531.49

STAGE 3 TRANSITION


1 0.011 0.008 1.38

2 0.0107 0.008 1.34

3 0.0107 0.008 1.34

4 0.01115 0.008 1.39

AVERAGE 1.36

AVERAGE FOR ENTIRE STAGE 3 1.45

Report Buzwagi

Documents

Transcript of Report Buzwagi