HG Leach?s Tahuna quarry began operating in 1992. In 2005, it took delivery of a Lokotrack LT1213 mobile impactor plant. The LT1213 joined an ST171 mobile screening plant. In 2007, an LT105 mobile jaw crushing plant was delivered and an LT272 mobile screening plant followed in 2009.
Apart from Tahuna, Leach operates three other quarries in the Thames Valley, all of which crush andesite.
The material at the Tahuna quarry is greywacke, which is much harder than the andesite at Leach?s other quarries. The result is a top quality final product, but it is tough on the machinery.
The LT1213 is currently fed a 300 minus feed. Production is about 500m3 to 600m3 per day, crushed over an eight hour day. ?We had been
running in closed circuit, but this can change depending on the demand from customers,? says Corrie Leach, mobile crushing manager.
The final products produced are a 65mm all-in, a 40mm, a 20mm and drainage ballast that are used for roads, on local farms, railway ballast and grading metals.
FLEXIBILITY IN OPERATIONS
The ease with which the crushers can be moved between Leach?s quarries has allowed the machines to operate at a specific quarry, depending on the product demanded at the time. The mobile plants have operated in Leach?s four quarries and have been contracted
out when they have not been needed.
?We like flexibility for the crushers to float between plants, which you can?t do with a static plant. This enables the best utilisation of our assets,? says Corrie.
?The ability to crush our finished product at the base has cut transportation costs. We have experienced cost savings by running our own equipment rather than hiring equipment.?
The flexibility of the machines means the operators can change the final product quickly while using the same crusher and screen. ?The LT1213 impactor is making good product in one hit, so we can use one machine instead of three,? says Corrie.
?Back-up and parts availability is the most important factor to our operation,? says Graham Leach, the plant and maintenance manager. ?This means being easily accessible to our plant to change wearparts.?
Most maintenance work is done by Leach?s, however they have the added advantage of being able to call on technical expertise.
?Preventative maintenance is always important,? states Corrie. ?Otherwise you run the machines into the ground. You need to keep on top of maintenance.?
Leach?s has a long relationship with Mimico, Metso?s distributor in New Zealand. The relationship started in 1996, when Mimico supplied them with MOXYs. ?Mimico is just down the road. It?s not too far to go to get parts or stock,? says Graham.
?The site has opened up more markets and customers,? concludes Corrie. ?People are happy with the product produced and service offered.?