technology
Many mining and aggregates operations have long used traditional products , such as woven wire cloth , for screens with great results . But for operations experiencing high wear and frequent screen changeouts , it ’ s worth looking into engineered screen media . Materials such as polyurethane , rubber , and perforated steel plates often handle heavy and abrasive materials better than woven wire . But operators need to know how to choose the best screen media for their operation .
The difference between using ‘ good enough ’ screen media and optimal screen media for the application can be unwanted downtime and expense . Consider three things when selecting the best engineered screen media for an application . First , look at all aspects of an aggregate or mining operation and any challenges to increasing production rates and profitability . Second , look at the composition of the material going through the vibrating screen and consult an expert from a reputable company to match the best screen media to the application . Finally , learn to install and maintain the screen media properly .
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The first step towards selecting the most productive screen media involves answering several questions . What material is being processed ? Is the screen media reaching a suitable lifespan for the operation ? And what sort of challenges are occurring with the current screen media ?
Consider the types of material going through the vibrating screen . Factors such as material size , weight and abrasiveness all come into play during the selection process . For example , screening gravel typically requires media with higher wearability to handle the material ’ s abrasiveness . Materials with top sizes as large as 25cm , on the other hand , require screens that are more durable because of the constant high impacts .
Next , look at the vibrating screen itself and complete a vibration analysis . Some analysis systems are designed to safely monitor vibrating screen performance in real time and detect irregularities before small problems lead to diminished performance or bigger issues . In some instances , the machine may be running perfectly , but changing the screen media can prevent screening irregularities and the resulting damage .
Consider the three phases that material goes through within the vibrating screen , from layered to basic to sharp . Producers can customise the screen deck with various types of screen media through each phase by accounting for open area and wear life to maximise productivity in each phase .
In the layered phase , as material of all sizes hits the screen deck , the media should handle a deep bed depth , high impact , and a mix of coarse and fine particles . Material should stratify in the middle of the deck during the basic phase , and near-size and oversize particles should be at the top of the material being screened . Virtually all undersize material should
QUARRY SA | march 2017 _ 29