3D scanning and the future of mining maintenance Part I

article image
Machinery and equipment scanning is providing a whole new aspect on mine site maintenance.

3D laser scanning has been slow to make an appearance in the mining industry.

While it has seen some use in surveying stockpiles autonomously, there had been little uptake.

However, over recent years the use of this technology at mine sites and plants has increased due to the distinct advantages it offers compared with traditional survey methods.

Point cloud data uses a 3D set of vertices represented by X, Y and Z coordinates that is gathered via 3D laser scanners.

Vast numbers of points are collated from a given surface to produce a high point density representation of an area or object.

This becomes particularly relevant to the mining industry in its ability to tackle vast, complex and even underground sites with far greater simplicity and convenience than conventional surveying.

Accuracy, time, and cost efficiency are just some of the benefits laser scanning has to offer.

From a detail d​esign perspective
Point cloud technology, from a detail design point of view, not only makes the job in hand that much easier, but minimises the potential for human error to almost zero.

The captured data provides an ‘as built’ status, giving a real-time snapshot of the site as it currently is and the subsequent data processing that follows has a fast turnaround.

This negates the risk of changes at site affecting plans, drawings and tenders.

The accuracy and coverage of the gathered data eliminates incorrect measurements or the need to make estimations.

In conjunction with CAD technology, specific measurements can be extrapolated to provide exact calculations.

For quality assurance purposes, using the point cloud data against prepared drawings is an excellent tool to clearly identify incompatibilities.

The data also has a multitude of other uses, such as clash detection of existing infrastructure and determining what aspects need to be removed, modified and in which order.

New designs can be reviewed internally and externally with client and maintenance teams, prior to fabrication and installation to identify potential problems and amend accordingly.

Additionally, the 3D point cloud data can be scanned to suit the plant coordinates or even a real-time satellite position.

This allows the new area being modelled to be positioned into Google Earth or any other real-time satellite imagery, allowing site a true aerial preview of the new construction.

Simplicity and ​convenience
The generation of a 3D replica of a physical object, regardless of size, layout or density can generally be performed while the plant is in production.
Site personnel can continue with site activities as their presence does not interfere with data collection.

This presents huge opportunities as the majority of the site can be surveyed during production without the need to schedule downtime and reduce productivity.

Where interior survey of, for example, a grinding mill is concerned, a short amount of downtime is necessary.

However, by using a laser scanning service such as MillMapper (Scanalyse, now part of Outotec), it’s possible to scan mills in as little as 15 minutes and this can be scheduled to coincide with a planned inspection shutdown.

Both MillMapper and CrusherMapper (used for gyratory crusher analysis) use patented, proprietary software to process laser scanning data, providing 3D files and reports on liner thickness wear and cross-sectional / longitudinal profiles.

Service life projections are given at the average and fastest wearing points.

Localised critical areas of breakage, cracks and uneven wear are highlighted, resulting in significantly improved liner assessment being provided as the total surface is mapped, not just accessible areas.

In terms of safety, both internal and external scanning reduce the need to work at heights or in confined spaces as laser scanners can be placed strategically in vantage points for remote scanning.

While a miner may potentially expect higher up-front costs due to production and manipulation of the data, the net results from minimised downtime alone will offset this cost.

This, coupled with the convenience of the survey, quick procedure and turn-around, along with clear, highly accurate and informative imagery, more than compensate over the course of the entire project.

The fabrication stage also benefits from the inherent precision in plans and drawings which will potentially reduce commissioning time.

A complete plant can be scanned within a day and the data files compiled into one or several 3D models and available to the design team within a short time frame.

High density imaging
The data produced from the millions of points captured in a 3D environment is generally processed via a CAD program.

These high density CAD images offer numerous advantages including versatility.

Sections of an image can be isolated or cut and viewed from any angle in the same way as a 3D CAD model.

The extensive data also provides the same detailed information of surrounding areas.

Exact calculations of space and measurement allow construction, access and craneage around existing infrastructure to be planned well in advance, without the need to revisit the site.

When processed, point cloud data images provide the basis for digital manipulation, giving an accurate, impressive and true representation of the project.

Whether rendered, false or true-coloured, the images are highly detailed.

Every fine point is captured which by any other method may have been missed, including non-documented assets such as cable trays, service piping and on-site modifications.

With so much information readily available in the digital files, time spent sorting through and analysing multiple drawings and site sketches is greatly reduced.