Multotec SSM’s Top 5 Magnetic Separation Innovations

A developed technology 

Magnets have been used to manufacture mineral processing machines for decades. Given their history, magnetic technology and physics are recognised as a developed art. In the global magnetic separation industry, the magnetic “heart” of the machine has generally remained unchanged and short of any revolutionary innovations. Rather, innovations help improve mechanical reliability, lower manufacturing costs and allow for easier maintainability and operability. As mine throughputs increase, Multotec continues to add larger machine models to the existing range. 

The Multotec Samplers, Solid/Liquid and Magnetic Separation (SSM) Division holds a strategic market in the industry, with mechanically strong and reliable machines that consistently deliver a low cost of ownership. It is through high-quality components that the SSM Division provides reliability across the product range. Yet, these components come with a price tag and there is always room for cost optimisation, which led Multotec SSM to the first of the top 5 innovations. 

1.    Lower cost procurement: leveraging off economies of scale

SSM General Manager, Jaco de Beer, negotiated an offset deal with the Division’s magnetic supplier taking losses or break-even cost on this product in exchange for reallocating gains on the sampler’s business. This resulted in a cessation of the silos experienced between samplers and magnetics procurement found within the SSM Division. 

The benefit is a reliable supplier that manufactures a machine with improved quality to that of competitors. Such an advantage benefits both new and existing SSM customers with continuously low cost of machine ownership.
 
 

2.    Improved technical sales support material 

With Covid-19’s influence, Multotec SSM has experienced less customer interaction over the last few months, which will continue into the foreseeable future. This means that remote sales will increase, and Multotec employees may not always have face-to-face opportunities to explain their machines and technologies to new clients (including those of overseas markets). 

In turn, Multotec has placed large efforts on the improvement of quote and tender documents to explain their products and technologies to customers (including those who use English as second language) in easy-to-understand terminology. These improved documents define the features, advantages and benefits these products and services hold for customers. 

Although Multotec already supports products with technical sales material, the Division has gone the extra mile to better explain their machines to assist clients with technical adjudication. Willem Slabbert, SSM Manager, believes that their quote and tender documents now match the quality of their equipment, which “stand out from the rest”. 

3.    Customers and colleagues are included in Multotec’s value offer

Multotec SSM’s customers often do not have to work at a level in which they fully comprehend how and why Multotec recommends certain machines or bespoke machine models for their application. Slabbert says that when these fundamental details are left unexplained, customers’ decision making (or technical adjudication) tends to lean towards lowest cost procurement.
 
To counter this, Multotec has implemented a sales tool document called an Application Brief per product, which has the following characteristics:

• Explains the application at a very high level, e.g. what an overbelt is used for; what the purpose of the machine is; what advantages/benefits there are for the client if they had a magnet (any suppliers magnet). 
• Finds out about the critical application parameters that affect the operation of the machine and the size selection. 
• The documents are short (1-2 A4 pages). 
• The tone and register are simple for anyone to understand. 
   

4.    Environmentally friendly overbelt magnet transformers 

An advancement in electrical technology allows for Multotec’s overbelt magnets to be more environmentally friendly. This is done by using an air-cooled system and replacing the conventional oil cooled transformer-rectifier with a digital based direct current generator. When this is done, no changes are made to the coil, known as the “magnetic heart of the machine”, but rather a change made in the electrical supply to the coil. 

The advantages of this air-cooled system are: 

• Increased energy efficiency with lower heat loss 
• More direct current control despite varying supply voltage surges into the control panel
• Increased electromagnetic coil protection 
• Smaller panel footprint and a lower weight
• No oil (does not pose an environmental oil spillage hazard)

It is important to note that these advancements are only cost-effective for larger model overbelt magnets.

5.    Wet Drum Magnetic Separator Level Control 

Wet drum magnetic separators do not work efficiently if the slurry level in the machine is low. Traditionally, this level is never controlled but regulated by mechanical means only. 

SSM has built a test rig that allows the underflow of the machine to be automatically controlled, controlling the level in the machine through an electro-mechanical linear actuator coupled to a hose clamp. 

Wet Drum Magnetic Separator showing level control rod (light blue) connected to closing pinchers (green & brown) at the machine underflow outlet hoses (black) which will be adjusted by the linear actuator (dark blue) acting on a torque arm system.

The control logic of the unit is provided by smart relay technology, a computer programmable device 90 % more cost-effective than a typical PLC. The smart relay allows just enough functionality in terms of its inputs and outputs to control this simple system. A level sensor in the tank informs the controller of the current tank levels. 

The controller then runs calculations, adjusting the linear actuator to open or close the underflow hose. If the hose opening is restricted more, flow out of the unit will reduce and the level in the tank will rise.

After testing, the design will be retrofittable to any existing magnetic separator (not only Multotec supply) and can greatly improve wet drum magnetic separator efficiencies.