CLOSED ON: 03 MAY 2021  |  REWARD: INR 10,00,000
Reward money is paid in exchange of legally acquiring the solution, implementing it to solve the problem and meeting the success criteria. Milestones for paying the reward money would depend upon the complexity of challenge and maturity of the proposed solution, which would be discussed with the solver as soon as the proposed solution is selected by us.
Under Evaluation

Short Description:

We are seeking solutions to avoid freezing and bridging of iron ore in Surge bin when ambient temperature drops to -20 to -40 DegC.

Challenge Details

We mine and process high-grade iron ore from our hematite deposits in the Menihek region of Labrador and northern Quebec, Canada. Fines and superfine material from our beneficiation plant are produced with minimum 64% Fe while our DSO (Direct Shipping Ore) facilities crush, screen and dry 60%-62% Fe iron ore for direct shipping.

The ambient temperature reaches -10 to -40 Deg C in winter and the low temperatures cause problems such as iron ore freezing and choking, thereby reducing the productivity.

Iron ore processing plant follows the process steps (refer figure 1) as below -

  1. Mine truck feeds hopper from blended iron ore stockpile
  2. From hopper iron ore goes to primary sizer which reduces the size to 100 - 250mm.
  3. It is then sent for secondary crushing which reduces to 75 mm
  4. It is then sent to Surge bin through 36” wide conveyor belt. These bins have 1000 tons capacity.
  5. After Surge bin, ore is sent to drum srubber through apron feeder where water is mixed in ore for further process of screening.

We are facing the problem in Surge bin. In winter season, ore starts freezing and bridging in Surge bin which chokes it and further processing cannot be done. Bridging is a no-flow condition in which material forms a stable arch (bridge, dome) in surge bin due to which ore flow is choked for down stream process.

We are seeking solutions to avoid freezing and bridging of iron ore in Surge bin when ambient temperature drops to -20 to -40 DegC.


The proposed solution should fulfil following requirements:

  • Avoiding iron ore bridging when ambient temp drops to -20 to -40 DegC even when the Suge bin is 75% full
  • Cost of solutions should be less than 1 USD/ton

Options tried:

1. CaCl2 is sprayed to avoid freezing of Ore. It helps to certain extent. High volume of CaCl2 creates issues in downward processing

2. Induced vibration to the Surge bin to smoothen iron ore flow.


Following constraints to be considered with solution -

1. Plant shutdown is not available for more than 10 days.

Have any query or need more clarification about this challenge?