The development of safe lifting tools for jaw crusher liners and cone crusher liners continues apace. A few years ago, they were rarely sighted or implemented. Today, the introduction of such devices to quarry and mine sites in all parts of Australia is well advanced and interest is being expressed from overseas operators. The change from traditional long-standing and outdated lifting techniques has now become the norm for customers.
The introduction of the lifting tools within Crushing Equipment Pty Ltd began in 2009 and continues with great support today from end users. Development began with the initial trials being carried out by Conundrum Holdings? Stawell Quarry and its quarry manager Brian Calovic and Crushing Equipment?s parent company Scaw Metals and sister company PWB Anchor, with key project personnel Tom Bruce, Lew Dilkes and Trevor Box.
{{image2-a:r-w:250}}The traditional handling, installation, removal and reversing of crusher liners from the introduction of rock crushers before 1900 was predominantly carried out using weld-on lifting lugs and, to a lesser extent, cast-on lifting hooks or lifting holes. The cast-on components often did not cover all handling requirements and in the main do not cover today?s standards for lifting requirements.
A committee comprising quarry operators, maintenance tradespersons and Crushing Equipment representatives carried out extensive investigations from 2008. The many existing lifting arrangements were reviewed, along with the training and procedures for weld-on lifting lugs. Although welding procedures were developed and welder training was supported for all operators, the outcome was not the answer. The most highly trained welder cannot predict the suitability of the cast manganese steel liner in its many metallic forms.
The days when crusher maintenance people knew they had to ?stand back? while lifting jaw or cone crusher liners with weld-on lifting lugs may have been lost along the way. The occasional mishap with a liner dropping onto the ground or equipment rarely gets reported. There have been fatalities, injuries and plant damage during the past 10 years that do not need to be revisited in this report. Further work
was required.
INTRODUCTION OF MANGASAFE
Crushing Equipment Pty Ltd had the crusher end user support and the expertise within its own company group to take on the challenge to introduce a lifting tool to cover both jaw crusher and cone crusher liners. The lifting tool had to meet the following criteria:
? It should be designed to eliminate the requirement for weld-on lifting lugs for handling, installation and removal.
? The lifting tool should be designed to support the crusher liner during the entire process of installation or removal.
This included eliminating the possibility for the liner to become disconnected from the lifting device during times of slack chains. This also included eliminating the requirement for the removal of the lifting tool prior to the liner being secured to the crusher, eg bolts fitted, etc.
? It should be designed to bend or distort before failure if overloaded.
? It should be designed with a working load limit greater than the load for each lifting eye.
? It would not include bolts or threads.
? The lifting tool should be tested and certified to Australian Standard AS3776. Test reports would be available for all end users. Ongoing inspection and testing would be included with other on-site lifting tackle annual inspections.
? The lifting tool would be positioned on the crusher liner to allow clearance for feed chutes and securing arrangements.
? It should be designed to accommodate both the top and bottom of a split jaw liner and include liner rotation where required.
? The design should allow the liner to be lifted at the correct angle to minimise manual handling of the liner into position.
{{image3-a:l-w:250}}JAW LINER LIFTING TOOL
The CE011 jaw liner lifting tool comprises two lifting eyes (WLL 4.0 tonne each) and a stabiliser bar. It is light, easy to use and manufactured, tested and approved for liners up to four tonnes. The jaw liner cast lifting holes are strategically located to angle the jaw liner against the crusher jaw liner backing plate without the use of additional mechanical aids (see Figure 1).
Lifting a jaw liner includes the following steps:
? The jaw liner lifting tool is used to lift the liner from the storage position (floor, pallet or other open container) to the crusher or from within the crusher during jaw liner change or reversal.
? Both lifting eyes are inserted into the elongated lifting holes and rotated 90 degrees in the recess cast into the fitting face of the jaw liner (see Figure 2).
? The stabiliser bar is fitted through the holes in both lifting eyes and locked into place with two clip pins (Figure 1).
? Lifting chains, including closed hooks attached to equal length chains, are attached to both lifting eyes.
? To remove jaw liners from the crusher, it is important to ensure they are free of any obstructions and all retaining bolts are removed before lifting commences. To remove the jaw liner from the crusher seating face it is important to ensure the two chains are evenly loaded and the combined load does not exceed the combined working load limit of the jaw liner lifting tool, lifting eyes or the working load limit of the chain sling.
? The jaw liner lifting tool is removed once the jaw liner is placed on the floor or container, or securely bolted to the crusher backing plate. The lifting holes may be filled with expanding foam to minimise the amount of crushing residue entering the lifting hole cavity.
CONE LINER LIFTING TOOL
{{image4-a:r-w:250}}The CE014 cone liner lifting tool comprises two lifting eyes (WLL 4.0 tonne each) complete with locking slides (see Figures 3 and 4). Elongated holes are cast into the cone liner to accommodate the two lifting eyes. The lifting eyes are strategically located in the cone liner to ensure a vertical lift without the use of additional mechanical aids (Figure 4).
Lifting a cone liner includes the following steps:
? The cone liner lifting tool is used to lift the liner from the storage position (floor, pallet or other open container) to the crusher or from within the crusher during liner changes.
? Both lifting eyes are inserted into the elongated lifting holes in the cone liner and rotated 90 degrees (see Figure 5).
? The locking slides are moved forward into the lifting holes and locked into place with two lynch pins (Figure 4).
? Lifting chains, including closed hooks attached to equal length chains, are attached to both lifting eyes.
? The cone liner lifting tool is removed from the cone liner once the liner is placed on the floor, in a container, or securely fitted to the crusher.
? At the completion of the cone liner installation the lifting holes may be filled with expanding foam to minimise the amount of crushing residue entering the lifting hole cavity.
{{image5-a:l-w:250}}SAFE OPERATING INSTRUCTIONS
The lifting tools are supplied with instruction booklets for all those involved with their use. It is important to incorporate these instructions for the jaw liner and cone liner lifting tools into site-specific operating procedures and work instructions. A Crushing Equipment representative can assist with these documents if required. A number of relevant points to be observed include:
? Inspecting the cast-in lifting holes before lifting a jaw or cone liner to ensure any excess wear or damage does not exceed the requirements included in the instruction booklets.
? Ensuring the liner is free of any obstructions and all locking devices are removed. Removing jaw or cone liners from the crusher presents issues due to manganese expansion onto side walls, locking onto seating faces or locking bolts not removed. To remove the cone or jaw liner from the crusher seating face, it is important to ensure the two chains are evenly loaded and the combined load does not exceed the combined working load limit of the lifting tool lifting eyes. Cranes with load measuring devices to protect all equipment from possible overload must be given preference for this task.
Crushing Equipment Pty Ltd has the design and manufacturing facilities to custom make liners for the quarry industry. This includes cast-in lifting holes for the lifting tools strategically placed to meet individual customer requirements. The total package, initially introduced to address the current safety issue identified by the committee, has led to significant cost savings due to the reduced time and crane hire required for liner changes.
Lew Dilkes is a qualified metallurgist with Crushing Equipment Pty Ltd.