GEMS Use of Gems Information Management Mulabisna

8/3/2019 GEMS Use of Gems Information Management Mulabisna

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THE USE OF GEMS AS AN INFORMATION MANAGEMENT TOOL - MULABISANA

THE USE OF GEMS AS AN INFORMATION MANAGEMENT TOOL

Jeffrey Mulabisana

De Beers Group, Venetia Mine

SYNOPSIS

Venetia mine is an open pit diamond mine located in the Limpopo Province, close to bordersof Zimbabwe and Botswana. The mine has about 15 kimberlite intrusions of which only twoare currently mined. The mine has been using and implementing GEMS for the past fewyears in an effort to integrate data to be manipulated and utilized more efficiently.Commencing with a drilling strategy that will enable the Geologist and GeotechnicalEngineers to achieve the most optimal results. GEMS is also used to provide an updated orereserve model for end-users to plan and design the mining process more efficiently. Gemsprovided a platform for better information management. At present, the ore reserve model isused to plan new drill sites for optimal information retrieval, updating the model with theexploration data as well as blast hole information to create a new updated and accurate ore

reserve model. Data is also manipulated in GEMS to determine the internal waste componentof kimberlite that may contribute to mining dilution. Both the ore model and dilution modelcontributes considerably to the planning and mining processes of the mine. The systems anddata that the Geotechnical Engineer uses, are integrated into GEMS to provide end userswith information like rockmass ratings, fracture frequency and blastability indexes. The endresult is block model being created and updated to view different features of the rockmass.

INTRODUCTION

Venetia is located in the northern part of the Limpopo Province, 30 kilometers south of wherethe Botswana, Zimbabwe and South African borders meet. The mine is approximately 80 kmwest of the town Musina and 37 km north east of Alldays.

Venetia Mine has integrated most of its mining systems in the past few years. GEMS(Gemcom Enterprise Mining System) has been a key software in integrating Geological,




Geotechnical, Survey and other mining data. GEMS has provided the platform for better information management. Thousands of data points can now easily be plotted to produce ablock model that becomes useful information for interpretation. This paper is aimed at givingthe reader a preview of some of the uses of GEMS as an information management tool atVenetia Mine.

GEOLOGY

Ore reserve drilling and delineation

In the last few years Gems has been used extensively to design diamond drill holes atVenetia Mine. Polylines of the existing geological model are used to identify areas that needto be drilled in GEMS. Trial holes are then designed to intersect the required geologicalfeatures at depth. Trial holes are displayed in both 3D and 2D views to see if they areintersecting the required geological features. Changes can be made to hole azimuth, dip, andhole position to design an optimal drillhole. The optimal hole position, azimuth and dip arerecorded and used to position the drillhole in the field. Figure 1 below shows some of holesdesigned in GEMS.

Figure 1. Section of Venetia Mine showing some drilled holes and planned holes for future drilling.

Once a hole is drilled and logged, the information is captured into a GEMS central database.The information captured from the drillhole is plotted in GEMS for interpretation. The ability toview the data in 2D and in 3D makes it easier to interpret the data. The attributes that one canlink to the data are also quite handy for further interpretation of drillhole information. SeeFigure 2 below for an example of the information one can extract from a database usingGEMS software.




Figure 2. Drillhole with different rock units depicted in different colours to show thelocal stratigraphy.

The information deduced from the drillholes is used to delineate kimberlite contacts and other lithological units. Geological block models are created from the identified lithological units.These block models are also updated regularly using additional drillhole information.

Ore Reserve Model Update

The ore reserve model, i.e. kimberlite geological model, is updated on a monthly basis inGEMS. During the mining process, blast holes are logged in the field and updated in GEMS.Blast holes positions are merged into GEMS through the Survey System. The geologistupdate geological information for each blast hole in Gems. Figure 3 shows a blast pattern withgeological information associated with each blast hole. The information from blast holes isused in GEMS to revise kimberlite contacts. Contacts are updated by revising polylinespositions. Updated polylines are then used to create solids for the block model.

Figure 3. Blast holes with their corresponding geological information.

Newly created solids are used by Surveyors to do their depletions. The integration of theSurvey and Geology Systems has opened an opportunity for the mine to reconcile monthly




volume depletions more efficient. The accessibility of the latest geological model has a far-reaching impact on the mine planning process. The integration of Survey and GeologicalSystems has not only opened the opportunity for the mine to reconcile monthly volumedepletions more efficiently, but also provided the short-term planning process with valuableinformation. Both the Short-term Planner and Blasting Engineer need the most updated andaccurate model to provide the miners with an achievable plan to conform to long-term budgettargets.

Selective blasting is one important and value adding process at the mine. To achieve this, theBlasting Engineer wants to avoid blasting waste and ore together in a single blast. The latestgeological model is used to design the blast outlines considering kimberlite/waste contactsthat will minimize mining dilutions and maximize grade. He also considers internal miningdilution and blastability indexes (next section) for optimal blast designs.

Pit Mapping

GEMS is also used in pit mapping. Previous maps have been scanned and integrated intoGEMS. This makes it easier for using this information together with other mining informationetc. The latest mapping techniques in GEMS gives us the opportunity to use point data todigitize maps on the screen using polygons. Attributes of each polygon are entered into the

system and basically describe the rock type and its structure. This system is still in its infantstage but it has shown a lot of potential for what we can call mapping information made easy.

Dilution Model

The ability to integrate information into GEMS from different sources makes it easier to makebetter geological interpretations. Drillhole and blast hole information was used to create adilution model for Venetia Mine K001 kimberlite. Figure 4 (a) shows waste rock embedded inthe kimberlite. To pick up features of interest in drillholes, display profiles were created to pickup those features only (Fig. 4b). It was easier to pick areas with high concentrations of waste.Different profiles can be used to extract different information from the same set of drillholes.The dilution model was used successfully for better mine planning and geological ore qualitycontrol.

(a) (b)

Figure 4. (a) A block of country rock within kimberlite, (b) Core holes in GEMSdiscriminating kimberlite from waste.

GEOTECHNICAL ENGINEERING

There are a number of systems and other data sources for Geotechnical Engineering use.This data has been integrated into GEMS to produce useful information for Geotechpurposes. Drill core, blast hole (Aquila System), Joint sampling, Bench Face Mapping are




main source of Geotechnical data. Figure 6 shows a schematic representation of Geotechnical Engineering data flow.

(a) (b)

Figure 5: (a & b). Schematic representation of Geotechnical Information managementsystem.

Drill core, face mapping and joint sampling information are entered into GEMS database

drilling workspace. Face mapping and joint sampling data is interpreted before entered intothe database. Whilst the information is in GEMS it is then used to create Geotechnical Blockmodels. Block models are used for designing purposes.

Rock Property Tests, Slope Monitoring, Failure Documentation, Failure Back-analysis, andPost-blast Face Analysis data is entered into a Geotechnical database, a Microsoft Accessdatabase. After the data is entered into the Geotechnical database, automated calculationsare done and information like rockmass ratings (RMR) for core logging and face mapping arefed into GEMS database. Block models are also created from the data integrated into GemsDatabase. Block models are used for information interpretation. Block Models are created toview different features of the rockmass like blastibility, rock strength, Fracture frequency etc.(Fig. 6).

Figure 6: Fracture frequency block model.

Block models created in GEMS are used to provide valuable information for risk managementand mine design. GEMS has become a very useful information management tool that reducesall the unwanted small tasks of data management and provides required information at a ver short space of time.

Information Management

Geotechnical

Database (Access)

GEMS Database (SQL)

Modelling and Design Processes

Automated RMR calculations

for Core Logging

and Face Mapping

Information Management

Drillcore Logging

Face Mapping andJoint Sampling

GEMS

Drill ingWorkspace

Interpretation

and Analysis

Geotechnical

Database

Rock Property Tests

Slope Monit oring

Failure Documentation

Failure Back- analysis

Post- blast Face Analysis




CONCLUSION

GEMS has been used creatively at Venetia Mine to integrate lots of data and to producevaluable information for both Geological and Geotechnical engineering and down the line endusers (the mine planners). In the same time more information becomes available for the firstend users like a short-term plan and blast outlines that helps communication between thedifferent sections on the mine. While there is a lot of potential to do more with the system, it

has at this stage been used to obtain very useful information. The importance of adding valueto the overall mining process must never be underestimated.

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GEMS Use of Gems Information Management Mulabisna