University of Saskatchewan Geological Engineering GEOE Introduction to Mineral Engineering

Lecture # 3  Production Rate Productivity Productivity Stope Production Stope Production Mine Production Mine Production  U/G Infrastructure

Productivity vs. Production  Productivity is the rate at which a task is completed or ore is produced. In mining it is usually reported in units per machine or man hour. Drilling: metres per drill - Hour Drilling: metres per drill - Hour Mucking: Tonnes per LHD - Hour Mucking: Tonnes per LHD - Hour Development: metres per man-shift. Development: metres per man-shift.  Production is the total amount produced. In mining it is usually the total production per day, week, month or year.

Determining Productivity and Production  Rule’s of Thumb  Benchmarking  Historical Data  Equipment Specifications  First Principle Calculations

Rule of Thumb   Rule of Thumb – An easy to remember guide that falls somewhere between an engineered solution and an experienced or educated guess.   Are the Rules always correct? Absolutely no. Can they provide a quick answer or a starting place? Absolutely yes.   The primary usage of Rules of Thumb should be in the development of conceptual designs and feasibility studies or, when a quick decision is required in the solution of an operating problem.   When the time arrives for final design and actual construction, Rules of Thumb are no substitute for sound engineering practices.

Productivity - Rule’s of Thumb

Mucking Productivity

Productivity - Drilling

Mucking Productivity - Trucking

Mucking Productivity Large Scoop

Benchmarking  Gathering information and statistically analyzing how other similar operation are performing. Production Production Productivity Productivity Cost Cost Safety Safety  Information is not always readily available.  Must ensure that orebody, skill of labour, work organization, consumable costs, etc. are in fact similar.

Benchmarking

First Principle Calculations  Zero based calculations where the production or productivity estimate is created by the mine engineer.  Typically used at the detailed design stage.  Equipment specifications, quotations, detailed drawings, established engineering practices form the bases.

Equipment Manufacturer  Equipment Manufacturers have detailed specifications for their equipment that will provide data on: Productivity Productivity Energy consumption Energy consumption Water Consumption Water Consumption Compressed Air Compressed Air Size of Openings Size of Openings Weights Weights

Equipment Manufacturer  The specifications are typically derived under ideal conditions.  The mine engineer must factor in site specific conditions such as: Skill of work force Skill of work force Environment (heat, depth, humidity) Environment (heat, depth, humidity) Condition of openings Condition of openings Hardness of rock Hardness of rock Maintenance Maintenance Availability and Utilization Availability and Utilization Play LHD Video

First Principle Shotcrete Calculation

Productivity Mucking Equipment

Mucking Productivity - Trucking

Productivity Drill Equipment

Tunneling Equipment

Historical Data  Usually applies to existing operations and is used to forecast production and create annual operating budgets. If a site does things the way they always did, can expect the same results. If a site does things the way they always did, can expect the same results.  Data gathered from time studies.  May also be used when estimating productivity, production and costs for an expansion.

Summary  In most estimating situations a combination of history, benchmarking, rule of thumb and first principle calculations are used.  CAUTION: in mining “stuff happens” It is important to build efficiency factors and reality into the estimate. Types of Delays: Types of Delays: Gas Check Equipment down Ground Conditions No Materials Surveying Air, water, vent, power Travel and Breaks

Equipment Availability  Rule of Thumb - New and/or well maintained equipment will have % effective availability

Equipment Utilization  Rule of Thumb - New and/or well maintained equipment should have 60-70% effective utilization

Equipment Reliability  Reliability: is the probability that a piece of equipment or system will perform its required function under stated conditions for a stated period of time.  MTBF: Mean Time Between Failures – how long a piece of equipment or system will operate before it fails.  TTR : Time to repair  Preventative Maintenance : routinely schedule equipment for service and inspection of key components  Predictive Maintenance : Schedule changeout of key components and major overhauls or rebuilds prior to equipment failure.

Example 1  Estimate development advance and metres per manshift in a typical development  Assumptions: RMR : Very Strong RMR : Very Strong 2 man Crew, 2 man Crew, 2 boom Jumbo, stoper for ground support, med sized scoop 2 boom Jumbo, stoper for ground support, med sized scoop Round size is 5x5x3.5 Round size is 5x5x3.5 Drill pattern requires 65 holes Drill pattern requires 65 holes Bolting pattern is 1.5x1.5 and 2m long bolts Bolting pattern is 1.5x1.5 and 2m long bolts

Example 1

Estimating Mine Production  Taylor’s Rule is a means of estimating Mine Life and Daily Production. It has been calibrated against many mines over several years and is adequate for pre-feasibility level estimates. L=0.2T 0.25 PR=T/(LxDPY) Where L=Mine Life T=Resource (inc. Dilution and Recovery) PR=Daily Production DPY=Scheduled Days Per Year

Example 2  Orebody A is t  The expected Recovery is 90% and dilution is estimated at 20%, therefore the Resource = 2mt x.9 x 1.2 = 2.16 mt  L=0.2T 0.25 L = 0.2 x ( ) 0.25 L = 7.7 years  If the mine is scheduled to operate 350 days per year, then the daily production is PR=T/(LxDPY) PR= /(7.7 x 350) PR ~ 800 tpd

Example 3  Orebody B is t  The expected Recovery is 80% and dilution is estimated at 10%, therefore the Resource = 20mt x 0.8 x 1.1 = 17.6 mt  L=0.2T 0.25 L = 0.2 x ( ) 0.25 L = years  If the mine is scheduled to operate 350 days per year, then the daily production is PR=T/(LxDPY) PR= /(12.95 x 350) PR ~ 3900 tpd

Example 4  Orebody A is a nearly vertical quartz vein containing 0.25 oz gold per tonne (insitu). It is a tabular, deposit that measures 215 metres on strike, 240 m high and 15m thick. It has a strong ore and f/w and a week h/w. The top of the orebody is 200 metres below surface and the bottom is 440 metres below surface. Both ore and waste have a SG of 2.6 t/m 3  The chosen mining method is Transverse Mechanized Cut and Fill.  Stope dimensions Have been established as 7m wide x 24m high x 15 m long

Example 4  Determine: Average tonnes per day per stope of ore and waste. Average tonnes per day per stope of ore and waste. Number of stopes required to meet daily production target. Number of stopes required to meet daily production target. The truck fleet size. The truck fleet size.

Example 5  Orebody B is a thick, tabular steeply dipping Nickel deposit with a diluted grade of 3% Ni. It averages 330 metres on strike, 400 m high and 40m thick. It has a strong ore and h/w and a moderate f/w. The top of the orebody is 100 metres below surface and the bottom is 500 metres below surface. The recovered ore has an S.G. of 3.8 and the waste has an SG of 2.6 t/m 3  The chosen mining method blasthole stoping with paste fill  Stope dimensions Have been established as 15m wide x 32.5m high x 20m long

Example 5  Determine: Average tonnes per day per stope of ore Average tonnes per day per stope of ore Number of stopes required to meet daily production target. Number of stopes required to meet daily production target. If 30 metres of development is required to access each stope, calculate tonnes of waste per day If 30 metres of development is required to access each stope, calculate tonnes of waste per day

Sequencing  Once the number of stopes are determined, they need to be sequenced  Considerations: Stress Stress Voids Voids Fill Cure Time Fill Cure Time Logistics (congestion on a level) Logistics (congestion on a level) Ventilation Ventilation Capital or access developement Capital or access developement

Chevron & Primary/Secondary Mining Primary Stopes Secondary Stopes STRIKE

Mining Sequence Sill level 1 PPPSS

Mining Sequence Sill level 1 PPPSS 2

Mining Sequence Sill level 1 PPPSS 2 33

Mining Sequence Sill level 1 PPPSS

Mining Sequence Sill level 1 PPPSS

Mining Sequence Sill level 1 PPPSS

Sequencing