CAMIRO Micro Bolter

Prototype Test Results

&

Data Analysis

January 01, 2009 through February 28, 2009

By:

2  

Table of Contents Introduction ................................................................................................................................. 3

History of Micro Mining .............................................................................................................. 4

Effects of Dilution ....................................................................................................................... 6

General Specifications ............................................................................................................... 7

Testing at 153 Ore Body ........................................................................................................... 10

Data Collected during Trials at 153 ......................................................................................... 15

Data Analysis ............................................................................................................................ 16

Conclusions .............................................................................................................................. 22 

 List of Figures Figure 1, Hand Held Drilling ....................................................................................................... 4 Figure 2, Long Tom ..................................................................................................................... 4 Figure 3, Single Boom Hydraulic Jumbo .................................................................................. 5 Figure 4, Tramming Configuration ............................................................................................ 9 Figure 5, Bolting Configuration ................................................................................................. 9 Figure 6, Deck and Access Layout ............................................................................................ 9 Figure 7, Feed configuration for 1.2m (4 ft) drill steel ........................................................... 11 Figure 8, Feed configuration for 1.8m (6 ft) drill steel. .......................................................... 11 Figure 9 COP 1022 Drifter with integrated steel locking feature .......................................... 12 Figure 10, Micro Bolter tightening screen to the back .......................................................... 13 Figure 11, Micro Bolter screening and bolting the shoulder and rib ................................... 14 Figure 12, Micro Bolter Operator on deck positioning screen ............................................. 14 Figure 13, Good Ground Bolt Pattern ..................................................................................... 19 Figure 14, Best Case Scenario Simulation ............................................................................. 19 Figure 15, Poor Ground Bolt Pattern ...................................................................................... 20 Figure 16, Worst Case Scenario Simulation ........................................................................... 20 List of Tables Table 1, Steel lengths, Feed travel and Back heights required .............................................. 7 Table 2 - Ground Support Installation Tasks Time Study Data ............................................ 15 Table 3 - Ground Support Installation Tasks Time Study Data ............................................ 16 Table 4 - Miscellaneous MICRO Bolter Tasks Time Study Data ........................................... 16

3  

Introduction The cost benefits of controlling dilution of extracted ore have been very well understood by miners and mining professionals for many years. However, as we strive towards more mechanization, the dilution factor has been compromised in order to fit “equipment” that is better suited to provide improved safety and productivity. Alternately, the drilling and ground support is accomplished by handheld drilling.

In 2007, a short study, commissioned by CAMIRO (Canadian Mining Industry Research Organization) on the safety of hand held drilling vs. mechanized drilling, concluded that the risk of injury with handheld drills was seven times greater than with mechanized drills. Armed with this data, MEDATech Engineering proposed to the CAMIRO group to fund development of a “MICRO Bolter”.

Project Objectives

The objectives of this machine were,

1. To operate within the confines of a narrow development or production heading from 8 ft x 8 ft up to 11 ft x 11ft (2.44m x 2.44m up to 3.35m).

2. To allow the miner to place various types of ground support without exposing the operator to unsupported ground.

3. To eliminate the risks of handheld drilling (fatigue, white hand, slips and falls and environmental factors such as noise and air borne contaminants).

CAMIRO found six industry sponsors (Barrick, Breakwater, HudBay, Teck, Vale Inco and Xstrata Nickel) and initiated the project in July 2007. The MICRO Bolter was delivered in November 2008 to NORCAT’s Underground Centre for initial testing and then in January 2009 to Coleman Mine in the 153 Orebody for a 60 day time trial.

The time study proved that the machine could function as designed within the confines of a small heading (2.44m x 2.44m), safely drilling and placing various kinds of ground support. The machine was deemed successful in all of its primary objectives. The following is a brief overview of the machine and simulations of productivity based on actual data measured at the 153 Orebody.

4  

History of Micro Mining The use of pneumatic jackleg drills dates from the early 1930’s. This facilitated the drilling of face holes in drift rounds particularly in small headings. Jacklegs have performed very well and remain in use today throughout the mining world.

Figure 1, Hand Held Drilling 

There was a progression to Long Toms to add drills and relieve some of the physical effort of the jackleg. 

 

Figure 2, Long Tom 

5  

Figure 3, Single Boom Hydraulic Jumbo

Productivity increased. Further refinements looked for increased mobility, larger, faster drills, three and more booms, electric–hydraulic drills, computerized jumbos and steadily larger headings became the norm. The local standard today is a 5m x 5m heading.

About seven years ago, the nickel mines started mining high grade copper stringers in the Sudbury West End Mines – Vale Inco’s Coleman and Xstrata Nickel’s Strathcona and Fraser Mine. These specific operations started looking for equipment that could operate in much smaller cross-sections, reversing the trend to ever bigger and bigger. Even so, the optimal drift size is compromised by the lack of suitable equipment.

The obvious technology drivers are safety and simultaneous dilution reduction.

6  

Effects of Dilution Dilution is the amount of waste that has to be taken to get the ore, usually expressed as a percent (100% dilution connotes taking one ton of waste for every ton of ore). Grades fall accordingly. Mines usually have a cut-off which in the Sudbury context would equate to a vein width of six or eight inches in an eight foot wide face. A one foot wide vein angling across the face of an 8x8 heading means about 600% dilution. Thus a vein sampling 30% copper would produce a mucked grade of about 5% with this geometry. There has not been any mechanized bolting equipment that would operate in an 8x8 heading. Wider headings have even lower grade, take longer to drill and muck, require more bolts and screen and in some cases longer bolts, especially at depth. The process gets more elaborate, time consuming and more prone to equipment delays. In simplistic terms, drift back stability is related to the inverse of the span cubed and dilution follows a square law. This makes larger headings very much less cost effective and slower.

In the following graph, dilution is plotted against drift size for vein widths ranging from 0.3m (1 ft.) to 1.2m (4ft.)

Dilution % vs. drift size

8x8 8x10 10x10 10x12 12x12

7  

General Specifications 

Minimum heading size – 7ft x 7ft with single stage feed or 4 ft single pass hole length.

Minimum heading size – 9ft x 9ft with compound feed system or 6 ft single pass hole length.

Maximum heading size – 11ft x 11ft

Drilling Type – Electric Hydraulic

Maximum Single Pass hole length – To Suit

Feed Type Steel Length Feed Travel Back Height

Single stage 4 ft 4’-4” 7’-0”

Double Stage 4 ft 4’-4” 7’-2”

Double Stage 6 ft 6’-4” 9’-0”

Table 1, Steel lengths, Feed travel and Back heights required

8  

Ground Support Hardware 1. Standard mechanical bolts

2. Resin re-bar

3. Friction bolts

a. Split-sets

b. Swellex

4. Other specialty products as specified by User

Mobility 1. Electric over hydraulic track drive

2. Easily disengaged and towable

3. Optional diesel driven power pack (towable)

Power Required 1. Standard power grid options

a. 575 v/60 hz/3phase

b. 460v/60hz/3 phase

c. 480v/50hz/3 phase

d. Others as requested

9  

Current Size Specifications

Figure 4, Tramming Configuration 

Figure 5, Bolting Configuration 

 

Figure 6, Deck and Access Layout

10  

Testing at 153 Ore Body 

Methodology of Testing at Coleman Mine 153 OB

The MICRO Bolter was dedicated to a single heading at the 4250 Level of the 153 Orebody at Coleman Mine (see Figure 1). This was done to ensure consistency in data collection and results. A single operator was selected to operate the MICRO Bolter on a Monday to Friday dayshift schedule (8 hr shifts). The operator was provided all information pertaining to the functionality of the machine with respect to the controls. MEDATech Engineering technicians were on hand at all times to aid the operator in developing bolting and screening procedures. The operator used basic hand held drilling techniques as well as using the machine to act as an additional set of hands to manage the screen.

Bolting in an area less than 2.75m (9 ft)

When the heading size allowed, typically 1.8 m (6 ft) bolts were placed in the back. The machine was designed to eliminate the need of the operator having to hold the drill. When drilling 1.8 m (6 ft) holes in an area where the back was less than 9 ft high, the operation required the feed to be retracted and 4 ft starter steel had to be used (4 ft single pass hole). Then once this 4 ft section of steel was drilled, the operator had to remove the steel and replace it with 6 ft steel to finish the hole.

Bolting in areas greater than 2.75m (9 ft)

When ground conditions demanded 8 ft bolts, the same procedure had to be followed as with the 6 ft bolts except in this case the feed could be extended to 6 ft single pass drill length. Therefore 6 ft starter steel could be used with an 8 ft steel to finish the hole to the desired depth.

11  

Feed Lengths Verses Hole Length (4 ft & 6 ft Configurations)  

Figure 7, Feed configuration for 1.2m (4 ft) drill steel 

Figure 8, Feed configuration for 1.8m (6 ft) drill steel. 

12  

Figure 9 COP 1022 Drifter with integrated steel locking feature 

Integrated Steel Retaining System The Copco 1022 hydraulic drill can be fitted with an integrated steel retainer. This allows the operator to use the exact same steel change procedures as he would if he were using a jack leg. The steel can be changed easily from the work deck or when operating from the ground.

This same system can be used to insert bolts by removing the steel and placing a bolt adaptor into the chuck of the drill. Again, this would be a very similar procedure if the operator were using a hand held drill.

13  

Screen Handling The type of screen used at the 153 OB was typically 11 ft x 5 ft welded wire mesh. Along with some input from the MEDATech Engineering technical staff on site, the operator used some trial and error in developing a technique to place the screen. He used a similar method as a miner working off the muck pile but also found that he could use the feed as an extra support arm to pin the screen in position. In addition to using the feed to hold the screen in place as bolts are placed, the operator used “push plates” and other common techniques to hold the screen in position as he drilled and placed the ground support on standard spacing’s.

 

Figure 10, Micro Bolter tightening screen to the back

14  

Figure 11, Micro Bolter screening and bolting the shoulder and rib

Figure 12, Micro Bolter Operator on deck positioning screen

15  

Data Collected during Trials at 153 

30‐Jan 31‐Jan 1‐Feb 2‐Feb 3‐Feb 4‐Feb 5‐Feb 6‐Feb 7‐Feb 8‐Feb 9‐Feb 10‐Feb 11‐Feb 12‐Feb 13‐Feb 14‐Feb 15‐Feb 16‐Feb 17‐Feb 18‐Feb 19‐Feb 20‐Feb 21‐Feb 22‐Feb 23‐Feb 24‐Feb 25‐Feb 26‐Feb 27‐Feb 28‐Feb6' Split Set Hole 5.25 6.92 7.47 7.33

8.23 5.02 5.1 5.826.08 5.27 5.87

4.986' Mechanical Hole 8.07 5.90 5.87 6.9 4.6 5.07 4.32 8.98 9.53 5.57

5.52 5.57 8.32 4.96 5.12 4.22 5.256.66 5.95 4.73 6.72 5.58 5.025.15 4.88 5.375.07 4.53 7.137.15 4.875.47 8.4810.33 7.511.5 5.575.42 6.326.07 5.637.7 76.53 5.975.03 5.727.68 7.57

11.325.46

8' Rebar 14.37 10.03 14.6 9.2311.57 11.23 15.72 9.9314.12 12.47 9.85

12.53 9.7312.65 14.6

6' Rebar 9.73 7.85 7.37 8.85 78' Mechanical Hole 8.32 7.7 12.03 8.13

7.77 7.57 9 9.86.18 9.32 8.4316.02 12

total number 9 0 0 0 0 8 0 0 0 0 16 5 0 4 0 0 0 0 18 6 0 3 0 0 0 0 14 13 0 0Total Time 83.22 0 0 0 0 74.36 0 0 0 0 109.05 30.58 0 21.66 0 0 0 0 119.67 32.14 0 19.25 0 0 0 0 142.67 111.29 0 0Average Time Per 9.246667 #DIV/0! #DIV/0! #DIV/0! #DIV/0! 9.295 #DIV/0! #DIV/0! #DIV/0! #DIV/0! 6.815625 6.116 #DIV/0! 5.415 #DIV/0! #DIV/0! #DIV/0! #DIV/0! 6.648333 5.356667 #DIV/0! 6.416667 #DIV/0! #DIV/0! #DIV/0! #DIV/0! 10.19071 8.560769 #DIV/0! #DIV/0!Time to place 40 bolts 369.8667 #DIV/0! #DIV/0! #DIV/0! #DIV/0! 371.8 #DIV/0! #DIV/0! #DIV/0! #DIV/0! 272.625 244.64 #DIV/0! 216.6 #DIV/0! #DIV/0! #DIV/0! #DIV/0! 265.9333 214.2667 #DIV/0! 256.6667 #DIV/0! #DIV/0! #DIV/0! #DIV/0! 407.6286 342.4308 #DIV/0! #DIV/0!Hours 6.164444 #DIV/0! #DIV/0! #DIV/0! #DIV/0! 6.196667 #DIV/0! #DIV/0! #DIV/0! #DIV/0! 4.54375 4.077333 #DIV/0! 3.61 #DIV/0! #DIV/0! #DIV/0! #DIV/0! 4.432222 3.571111 #DIV/0! 4.277778 #DIV/0! #DIV/0! #DIV/0! #DIV/0! 6.79381 5.707179 #DIV/0! #DIV/0!

Table 2 - Ground Support Installation Tasks Time Study Data

16  

Data Analysis The mean, minimum and maximum values for all Bolts are found in Table 3.

Table 3 - Ground Support Installation Tasks Time Study Data

Ground Support Installation Tasks Number of data points

Time (min)

Mean Minimum Maximum

Install 6' rebar 5 8.16 7.00 9.73

Install 6' splitset 12 6.11 4.98 8.23

Install 6' mechanical bolt 51 6.37 4.22 11.50

Install 8' rebar 15 12.18 9.23 15.72

Install 8' mechanical bolt 13 9.41 6.18 16.02

Other tasks not specific to ground support type were noted and are displayed in the table 4.

Table 4 - Miscellaneous MICRO Bolter Tasks Time Study Data

Task Number

of events

Time (min)

Mean Minimum Maximum

Pre-Op time at beginning of shift 8 9.92 4.20 16.55

Install new section of screen 17 4.64 2.52 8.78

End of shift preparation 9 6.89 3.20 13.17

Move machine to adjacent heading (maximum tram distance of 81 feet)

7 7.12 3.37 12.56

Miscellaneous tasks/delays 10 9.21 3.95 20.47

17  

The approach taken to analyze the data was to consider the Vale Inco standards for ground support as a standard datum. From this we determined how long the bolting cycle would be for a best case and a worst case scenario (good ground conditions and poor ground conditions. This standard datum was developed from Vale Inco ground support policies for Narrow Vein Headings. (See Appendix A)

From the standards, a bolting and screening pattern was developed for standard narrow vein headings in good ground conditions as shown below in Figure 13. In addition to this, an additional bolting pattern was developed for 11’x5’ screen in poor ground conditions as shown in Figure 15.

18  

CAMIRO Simulation Methodology  

How simulations were conducted:

1. Determine the number of occurrences per cycle of (this can be user specified or

statistically approximated from the collected data)

a. Screen

b. Moving of machine (tramming)

c. Interruptions

d. Pre-operations (prepare material)

e. Post-operations (cleanup work place)

f. Bolts

i. 6’ split sets

ii. 6’ mechanical bolts

iii. 8’ mechanical bolts

iv. 6’ resin re-bar

v. 8’ resin re-bar

2. For each occurrence from point #1

a. Select a random data point (time) from the collected data for each

occurrence of each task.

b. Sum all of the above to achieve a cycle time.

3. Repeat #2 for 100k times, store each cycle time independently.

4. Determine the range of #3 (min-max)

5. Create 30 ‘bins’ or ‘buckets’ for #4 (range)

6. Sort #3 (cycle times) into the 30 bins – (each bin has a range ie.. 6.2-6.4 hours) –ie 2.. if there are 8 cycle times between 6.2 and 6.4 hours then increment the 6.2-6.4h bin by 8.

7. Plot the results

19  

Simulation 1 Best Case Scenario • Boundary Conditions:

o Good Ground o 2.44m (8 ft) x 2.44m (8 ft) heading o Standard bolt pattern for good ground

Figure 13, Good Ground Bolt Pattern

Figure 14, Best Case Scenario Simulation

20  

Simulation 2 - Worst Case Scenario • Boundary Conditions

o Poor Ground o 2.44m (8 ft) x 2.44m (8 ft) heading o Standard bolt pattern for bad ground

Figure 15, Poor Ground Bolt Pattern

Figure 16, Worst Case Scenario Simulation

21  

Simulation Summary

The two cases simulated above from Figures 14 & 16

Case Maximum (Hrs) Minimum (Hrs) Standard Deviation

Average (Hrs)

Best Case 3.54 2.19 0.15639 2.87

Worst Case 5.15 3.67 0.18156 4.41

Time Delta 1.60 1.47 0.02517 1.54

 

22  

Conclusions Although the data was limited, the simulations show some promising results. The machine definitely provided the operator the safety and protection from all the environmental factors related to hand held drilling. The productivity numbers of the simulations also indicated that these goals are achievable, given a reliable machine. Further design enhancements will be required in order to achieve reliability, however, for a prototype, the machine preformed remarkably well and was not the cause of any significant delays. The operator did damage the water tube of the drill due to some inexperience with the system but the machine was never damaged. The machine did not require any hose replacements which is always a concern with machines of this nature. Further field testing is required in order to fully develop a matrix of data that can be considered large enough to produce accurate simulations. However, based on the data collected during the Coleman test, the machine achieved all of its three primary goals as defined at the onset of the project.

23  

Appendix A: Vale Inco Bolt Standards

24  

Appendix B: Simulation Scripts

BOLTER STUDY - 8ft x 8ft x 8ft round

11ft x 5ft screen 

 

Load VALE INCO time study data clear;

load bolterstudy;

Settings num_of_studies=10000; % number of studies

num_screen_head=4; % unmber of 8'x 4' screens per heading

num_bolt_screen=5; % number of new bolts per screen <-overriden if absolute is set to 1

num_tram=1; % number of times to tram per cycle

pre=1; % 1 to add pre to cycle times 0 to not

post=0; % 1 to add post to cycle times 0 to not

interuption=1; % how many interuptions per cycle

bins=30; % how many bins to split results into

agressive=1; % bolt pattern = 1 for aggressive- 0 for conservative -2 for medium

% overriden if absolute is set to 1

bpat='4ft x 2.5ft pattern'; % Bolt Pattern pattern

absolute=1; % User specified bolt pattern! fill in variables below!

%%%%%%%%% if absolute set to 1 then fill in below %%%%%

s6=6; % number of 6 ft split sets

m6=23; % number of 6 ft mechanical

m8=0; % number of 8 ft mechanical

r6=4; % numbrt of 6 ft resin rebar

r8=0; % number of 8 ft resin rebar

25  

Bolt time Variable init time_8m=0;

time_6m=0;

time_8r=0;

time_6r=0;

time_6s=0;

time_screen=0;

data length init %%%% bolts

dp_mech6=size(mech6,1);

dp_mech8=size(mech8,1);

dp_split6=size(split6,1);

dp_rb6=size(rb6,1);

dp_rb8=size(rb8,1);

%%%% Misc

dp_screen=size(screentack,1);

dp_tram=size(tram,1);

dp_preshift=size(preshift,1);

dp_postshift=size(postshift,1);

dp_inter=size(interuption,1);

26  

Appendix C: Conclusions and Recommendations of Vale INCO Following Testing at Coleman

Conclusions and Recommendations

The MEDATech Micro Bolter proved that it was capable of bolting in small and large narrow vein headings. The safety benefits were shown on several occasions when loose fell down and struck the machine rather than risking injury to the operator if he were to be operating a stoper drill.

Some recommended modifications requested from the operator, maintenance and management were made in order to render the machine desirable for use at Vale Inco sites. These include:

• Adding a cable reel to the machine. However, there is a concern about maneuverability if the unit becomes too long, thus a cable reel installation should take this into consideration.

• Improving the design of the centralizer.

• Providing more on-board storage capacity.

• Providing handles and steps on the boom to allow the operator to climb up to the collar of the hole to cut screen or insert resin cartridges.

• More maneuverability of the drill table to make it more versatile to drill slashes or test holes in burst-prone areas.

• The front and rear jacks require longer strokes.

• Self-propelled carrier or drive system to make the machine independent of other equipment in the mine.

• Hydraulic hoses need to be re-routed or a bracket installed.

27  

• Reliability and certification of the remote control(s) need to be addressed.

• The addition of a hammer function on the remote control would be beneficial. It is understood that safety interlocks would have to be in place to ensure the hammer isn’t activated inadvertently. Otherwise, it is suggested to relocate the hammer switch.

• In order for the remote not to get lost or damaged, it would be good to have a spot to store the remote unit.

• A wearbar or protection for the main boom mounting bolts where it rests on the floor would be of benefit. When they wear out or break off, the feed assembly will fall.

MEDATech has recognized some modifications as well. They intend to develop proper mounting interfaces for screen pushers to allow them to be more effective for the operator. This was realized during testing at NORCAT and was to be investigated underground at Coleman but it is unknown what the results of this investigation have concluded.

The overall consensus from operations was that the drill did perform well. At the end of the trial, it could bolt about 65% as fast as a jackleg/stoper and the operator felt with enough experience and all the bugs worked out, and with the additions requested, it would be very close to bolting on par and, of course, be safer to use.