Mpumatech Mining – Split Sets + Washers
Mpumatech, has in a recent drive to expand our product range and after exploring all industry needs for rolled products, have decided to focus on the manufacture of split sets / friction anchors for underground mining and civil engineering projects. Mpumatech have now developed their own split set friction anchor which we manufacture alongside our main product ranges at our facility, conveniently located in Witbank, close to major transport links and hubs in Johannesburg.
Split sets / friction anchors have been used as a primary roof support in the underground mining environment for many years. The anchor consists of an open seamed high tensile Supraform S420 steel tube with a face plate. One end is tapered for easy insertion into a pre-drilled hole. It is installed by driving the assembly into a marginally smaller hole than the split sets diameter and the welded steel ring then provides the necessary support to hold the washer plate in place. The set then uses friction to anchor itself along the whole length of the bolt by relying on the radial spring force generated through compression of the tube. Split set technology is used worldwide by many mines for an extensive variety of mining applications.
Key Advantages of using Split Sets
- Fast and easy installation
- Full length support
- Effective support at any angle
- Cost effective
- Axial and radial support
- No torqueing or re-torqueing
- No special equipment is required
- Improved rock stability
Changing Ground Conditions
Pull testing on the split set friction anchors proves their superiority in anchoring themselves inside the drilled hole. Once the product has been installed, the spring loading allows the anchor to adapt to minor changes in the ground conditions. This is an important advantage over inelastic bolts that are unable to adapt to changing ground conditions.
The split set is a popular choice due to its easy installation. Once the hole is drilled, the driver tool drives the anchor into the wall. Installation time is typically less than a minute and there is no waiting time for grout to set, no tightening or torqueing and no ongoing maintenance is needed after installation. This saves time, labour and additional grouting or resin expenses.
Split set friction anchors are available in 33mm, 39mm, 41mm and 46mm diameters in a variety of lengths to suit the application of the mine. Depending on the strength and corrosion requirements, we offer S420MC Supraform as well as 3CR12 stainless steel. The domed bearing washer plates are available in 125 x 125 x 4mm and 150mm x 150mm x 4mm as well as the Combi Plate 300mm x 270mm x 1.6mm.
Custom specifications are available for large orders.
Mpumatech wraps and straps all products in high quality packaging with metal straps designed to withstand the rigours of transport by road and sea. This ensures damage is eliminated or kept to an absolute minimum during transport.
The pull test is a common method to determine the effectiveness of the split sets. From each batch Mpumatech tests a split set in our in-house laboratory to ensure that the product conforms to the required load.
The first part of the curve signifies the elastic deformation of the steel, the set-up of the test apparatus and the split set. The initial slip load, which is the load at which the split set firsts moves in its hole, is considered to be the split set’s pull-out strength.
The scale of the slip load depends on an array of factors, including the contact area between the Split Set and the rock, the size of the drill hole into which the bolt is installed, properties and type of the rock, the time passed between split set installation, the pull test and the quality of installation.
he pull test should not be regarded as a conclusive measure of the split sets capacity but rather as an index test and one that can give an idea of the expected performance of the split set.
Both in-house and an independent laboratory tensile test are conducted on Mpumatech manufactured split sets to confirm the product conforms to the published specification and to offer complete transparency to the client. Mpumatech clients can rely upon the standard, consistency and quality of our split set units as supported by these ongoing tests.
Introduction to 3CR12 Stainless Steel Split Sets / Friction Anchors
A key concern of split sets relates to their useful life span in an underground environment. They are vulnerable to corrosion and can become ineffective after a short period of time, with this in mind we now offer 3CR12 Stainless Steel split sets.
Our 3CR12 Stainless Steel split sets, with similar high tensile properties, is available at a similar price point to the galvanised split sets. Where absolute peace of mind is required, the 3CR12 split set will meet even the most demanding safety standards.
We have conducted salt spray tests to compare the performance between galvanised and stainless steel split sets and the results show the advantage of using 3CR12 material, please click on the following link for the test report:
Key Advantages of 3CR12 Stainless Steel Split Sets
- Superior corrosion resistance
- Recommended for areas high in acid and salinity
- Galvanised material scratches off when inserting into the hole compromising the steel to the corrosive elements, stainless steel can scratch and remain effective
- Cost effective compared to galvanised split sets
- Can outlast galvanised split sets where they fail over time
To view our online split set brochure, please click on the following link:
For any enquiries for our manufactured split sets / friction anchors please send us an email to firstname.lastname@example.org or complete the form below