Mills (alignment, gear reversal, base plate refurbish and more)
Mills and Scrubbers are rotary vessels used in the beneficiation process throughout the mining and cement & coal industries and are usually gear driven by making use of girth gears and pinions. These require regular inspections and maintenance. We have a highly skilled team and equipment that is capable of executing repairs, inspections and maintenance on these.
Baseplate failure is a common problem when it comes to high powered equipment such as mills and scrubbers, this results from incorrect alignment and vibration. We own the required equipment to remove, refurbish and reinstall base plates up to the required OEM specifications and tolerances.
For aged mills where OEM parts are no longer available, we’re able to deliver engineering solutions.
Our vast skill set and equipment allows us to work on dry and wet mills, trunnion or shell support.
Robtek ensures:
Radial and axial alignment to the highest standards and to strict tolerances that is essential with the installation and reversal of girth gears.
The use of state of the art equipment and highly skilled staff to ensure complete drive train alignment.
The highest standard regarding skill, tooling and workmanship when doing pinion alignment.
Our team has been executing alignment of gears on various manufacturers equipment for the last 30 years.



Kilns and Dryers (chair plate replacement and seal repairs)
Our experience and expertise in Kiln and Dryer mechanical maintenance are immense.
We have an in-house loose-fitting chairplate design that has been successfully rolled out on both kilns and driers across Southern Africa, for clients such as Sappi, Idwala Lime, PPC and Foskor to mention but a few.
We can assist clients who have lost retainers by jacking tyres back into position over rollers. This can be done without having to lift the kiln/drier.
We are the preferred installer of ITECA seals in Southern Africa and have experience in the maintenance and installation of various seal designs.
Robtek ensures:
Advice on chairplate design, tyre shimming, cold gaps and creep.
Pain-free installation, minimal thermal stress to the shell and easy adjustment of shims when using our own chairplate design.



Alignment and Grinding
Our hot kiln alignments are performed with the latest industry leading equipment and theodolites. This is done in conjunction with a comprehensive kiln inspection which encompasses every mechanical aspect of an operating kiln. Our recommendations are based on findings and presented back to the client in the form of a presentation, this aims to ensure client’s get the most out of our reports and effective corrective action can be taken should it be required.
Alignment measurements include:
Plan and elevation view alignments.
Shell eccentricity and profile
Shell temperatures
Ovality
Tyre creep
Roller slopes and skew
Non-conductive gear runouts and shaft deflection.
We’re able to assist with the service and repair of any mechanical issue highlighted in the report including: roller adjustments and replacements, gear and drive chain servicing, shell replacement, tyre and roller resurfacing, chain plate shimming and replacement, seal maintenance, crack repairs and thrust roller maintenance.
Tyre and roller resurfacing is done to eradicate tapers, concavity, deformation and/or poor surface contact. This is preferably done ahead of alignment so that any changes in roller or tyre diameter can be accounted for in the alignment recommendations.
HPGR’s (studs, rolls and more)
HPGR’s, also known as High Pressure Grinding Rolls are highly efficient crushers used in the mining industry. Specifically the diamond mining industry as it is the only grinding crusher that would not break undersized diamonds.
The rolls consist of a steel roll fitted with tungsten carbide studs that affect the crushing. Depending on the wear of the studs, it may require replacing. The maintenance would require periodic replacement of the rolls and drive train.
With our highly skilled and experienced workforce and comprehensive range of tooling and equipment, we’re able to assist with the repair and replacement work on HPGR’s.




Furnaces (slipper pads)
With Metix being the leaders in electrodes and electrode bus tubes, we’ve successfully installed and maintained many Metix slipping devices, electrodes and electrode bus tubs on numerous projects.
Typical slipping device servicing includes:
The installation of contact shoes on electrodes.
Installation of all stainless steel hanger brakes and stainless steel welding on electrodes.
Installation of an electrode bus tube and the soldering to copper tube joint contact shoes.
Rigging of electrodes and contact shoes
Installation of power packs and a large amount of hydraulic tubing going through tight corners and small openings leading to electrodes and slipping devices.
Installation of cooling water lines and the testing of each line to ensure there is no water leak.
Installation of isolation blocks to ensure there is no electrical arc. We also perfect arc testing.
Air Filters and Precipitators
Air filters and precipitators are high wear parts within a plant due to the abrasive nature of the particles within the airflow. We have experience in both the ongoing repair and the complete retrofit of equipment from various international OEMs.
Our combined skills of boiler making, welding and fitting allow us to repair air filters and precipitators of every kind
Typical procedures included in the repair and maintenance include:
The removal of cladding and other obstructions where required.
Cutting of existing worn and/or crumbling casing plate sections and replacing with a new part.
Checking of all collecting plates/bags for excessive build up or burn marks and looseness.
Inspection, repair and replacement of emitter bars/bag cages.
Inspection and replacement of rapper shafts and hammers.
Inspection and replacement of insulators.
Inspection and replacement of internal, hopper or collection unit plate work.




Gas Producer
Gas producers are critical components in advanced pulp, paper and synthetic molecular chain plants.
Typical servicing involves:
The removal of ash pan, skirting and grate, and coal feeder.
Opening of all manholes, coal feeder vent lines and the removal of ash cam breakers.
Opening tar cyclones, deterrer seal pot, isolation valves and dust cyclones, then repair or replace.
The repair of producer shell and poke holes.
The replacement of grate, flange and poke hole seals
The reinstallation of coal feeder, grate, skirting and ash pan.