Client: Kumba Iron Ore – Sishen Mine
Project: DMS Primary Crusher Replacement Project – Crusher Concrete Base & Shaft Structural Vibration Analysis
Year: 2021
In 2021 Sishen Mine endeavoured to replace the existing ageing Nordberg Gyratory Crusher. The following analyses and designs were performed in order to ensure suitability, adequate safety of design and serviceabillity of the existing structures to accommodate the new gyratory crusher:
- The capacity of the floor to resist the new crusher loads were analyzed.
- A dynamic vibration analysis of the crusher shaft concrete structures was performed to identify possible frequencies in the plant that could cause resonance with the new crusher operating frequency. Due to uncertainties varying soil parameters were adopted in order to most accurately model soil-structure interaction. Dynamic amplification of the building response will occur if the exiting frequency fe is close or equal to the natural frequency fn of a significant vibration mode of the building. To avoid resonance, the natural frequency of any significant vibration mode must be outside the boundaries specified by the relevant Anglo American Specification for which fn ≤ 0.6 fe or fn ≥1.4 fe.
- A comparison was made between dimensions of the existing and new crushers. Differences in dimensions were highlighted and their implications on installation and maintenance considered.
A Crusher base repairs were designed together with a suitable repair methodology.
