UNDERGROUND LASER SCANNING SYSTEM AIDS GOLD MINE

13 May 2008, 10:00am

Underground surveys at a major US gold mine are being carried out more effectively by using a Cavity Autoscanning Laser System (C-ALS) from laser measurements specialists, Measurement Devices Ltd (MDL). Cavity and stope surveys are being made faster and more cost-effective for Newmont Midas Operations, Nevada, thanks to a C-ALS acquired from Measurement Devices Ltd, York, last year (2007).

CLEAR VIEW: One of the team at Newmont Mines studies images of a stope void gained by using a Cavity Autoscanning Laser System (C-ALS) from laser measurements specialists, Measurement Devices Ltd (MDL).

Newmont Mining Corporation, founded in New York in 1921, is among the world’s major mining operations with precious-metals mines on five continents and 34,000 staff.

Midas Operations, which started production in 1999 and was acquired in 2002, is part of Newmont’s Nevada Operations. Newmont’s Nevada Operations began in 1965 and encompass a range of surface and underground mining facilities. Current underground operations which form part of Newmont Nevada include Midas, Leeville, Deep Post and Chukar. Total underground production for 2008 is budgeted at two millions tons.

Newmont Midas Operations, where the C-ALS is in use, is a single, underground gold mine producing 300k of ore each year as well as significant amounts of silver.

MDL, which also has offices in Aberdeen and Houston, Texas, launched its new 50mm/1.97” diameter C-ALS in 2006 for carrying out remote surveys of subterranean voids and cavities from above ground to enhance safety.

The slim line C-ALS, which represents a first step in `key-hole scanning’, can be operated through 50mm diameter boreholes drilled in any direction. Angled holes can be drilled from the surface, or from other underground workings, to intersect abandoned workings, voids and stopes 100s of meters from the surface or borehole origin.

Chief mining engineer for Newmont Midas Operations, Chris Johnson, says: “We are using C-ALS to survey stope voids where normal access to the stope is inadequate.

“We previously used another system which we still operate for other surveys but C-ALS fulfils a unique and valuable need where access is limited. With the other surveying system, underground stope surveys are possible only with a drift access and where the system can be deployed into the void.

“If access to the void is limited, the quality of surveying with the more traditional system is likely to be inadequate due to survey shadows.

“However, with the unique, tube-like design of C-ALS, access to the stope void can be done easily through a four-inch drill hole. Because this is far faster and more cost-effective than drift access, numerous holes can be drilled into the stope void. This enables several surveys to be conducted at different locations within the void which minimises stope shadows and a higher quality result can be achieved.

“As only the tip of the C-ALS unit is exposed in the void, the risk of equipment damage is reduced compared with other equipment which is totally exposed and could be destroyed by a rock fall. An added benefit is that, after some basic training and set up, C-ALS is relatively user friendly.”

MDL business development manager in Nevada, Rick Tolhurst, says: “Newmont Midas Operations is gaining real operational benefits from C-ALS. The system’s unique ability to measure and monitor underground cavities via a borehole is playing a key role in the safety of underground mining by providing a new, safer way for engineers and planners to study underground voids and decide how best to address them as part of their operations.”

MDL, which recently launched its first overseas franchise in Australia, has four strategic business units for laser modules, handheld laser systems, laser systems and dynamic systems and generates 80 per cent of its sales outside the UK.

For further details on Measurement Devices Ltd (MDL), please contact marketing director, Elaine Ball, tel: (01904) 791139.

Mike Clarke

Media Giants PR Ltd, Tel (01423) 5688