When a gold processing plant required sampling equipment, McLanahan was able to improve the site’s process flow and quality outcomes with an innovative crushing and sampling solution.
The customer, an Australian gold producer, required sampling equipment for its gold processing plant. They had employed the services of an Engineering, Procurement and Construction (EPC) contractor to design and engineer the plant and to run the tendering process for the equipment.
The original plan required a sampling system to sample the product from the High-Pressure Grinding Roll (HPGR) crusher prior to feeding into the agglomerator. It would then analyse the ore’s size and quality to ensure optimal performance of the agglomerator. However, during the tender evaluation process, the customer and the EPC realized that the crushed product from the HPGR, which is comprised of compressed flake material, would need to be broken down further prior to feeding into the agglomerator.
Improved Flowsheet Design
After discussions with the customer, the McLanahan engineering team proposed a change to the flow sheet design. The new and improved circuit would include additional crushing equipment to efficiently crush the oversized flakes from the HPGR prior to it being sampled and received by the agglomerator. This solution was accepted by the customer, and an updated sampling system package was then sent out for tender to include the additional crushing equipment.
The crushing and sampling equipment supplied by McLanahan is tailored to the feed material specifications and the compact site layout. The McLanahan engineering teams in Australia and the United States were able to provide the customer with swift clarifications to all technical queries and clarifications as per the customer’s requirements. Feeback from the tender process confirmed that McLanahan’s timely and detailed technical support allowed them to complete their technical evaluation quickly.
New Customer: Unique Solutions
McLanahan was successfully awarded the tender for both the crusher and sampling system in 2021.
The crushing equipment supplied is a McLanahan DDC-Sizer that is designed to break oversized flake material from the HPGR while passing the greater proportion of on-size product at a maximum throughput capacity of 1,000t/h.
The DDC-Sizer 24x48-T-2x75(IR) is a specialised crushing machine that features:
- 24” (800mm) diameter x 48” (1.2m) long inward rotating crushing rolls
- A heavy-duty exterior frame
- An automatic lubrication system
- Two 75kW electric motors
- Specifically engineered segments
The segments feature a non-standard design with a high void tooth pattern. They were specifically designed by the McLanahan engineering team to handle the flake material. This tooth pattern produces a high level of interparticle crushing, which takes advantage of the highly friable nature of the flake material to break up the flakes and pass the required tonnage rate.
The Two-Stage Falling Stream Sampling System is designed to extract samples in increments from the DDC-Sizer discharge, and features:
- A primary horizontal carriage bottom dump type sampler
- A vibratory sampler feeder
- A secondary horizontal carriage bottom dump sampler
- A four-station rotary sample collector
- An electrical control package
- Additional chutes and sample supports
The DDC-Sizer was assembled and tested at McLanahan’s Newcastle facility, and the sampling system was manufactured by the McLanahan team in Pennsylvania. The equipment was successfully delivered and installed on site, with the McLanahan Field Service team providing installation and commissioning supervision.